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Sample records for dental restorative materials

  1. Radiopacity of dental restorative materials and cements

    International Nuclear Information System (INIS)

    Kang, Byung Chul; Yang, Hong So; Chung, Hyun Ju; Oh, Won Mann

    1994-01-01

    The radiopacity of six composite resins, three resin luting cements and ten filling materials were studied. The purpose was to obtain an indication of radiopacity value of different brands within each of these groups of materials and to show differences in radiopacities of filling materials and natural tooth structures. On radiographs, the optimal densities of standardized samples were determined by computer imaging system and radiopacity values of the materials were expressed in millimeter equivalent aluminum. Within to groups of materials studied, there was considerable variation in radiopacity. The composite resins of P-50, Zl00 and prisma AP. H displayed much higher radiopacities than aluminum. Panavia resin cement was shown to be similarly radiopaque to aluminum. Generally, the radiopacity of base and filling materials appeared to combined applications for restorative treatment of teeth, lower radiopacity can interfere with the diagnosis and detection of gaps near the restoration.

  2. Various Effects of Sandblasting of Dental Restorative Materials.

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    Goro Nishigawa

    Full Text Available Sandblasting particles which remain on the surfaces of dental restorations are removed prior to cementation. It is probable that adhesive strength between luting material and sandblasting particle remnants might exceed that with restorative material. If that being the case, blasting particles adhere to sandblasted material surface could be instrumental to increasing adhesive strength like underlying bonding mechanism between luting material and silanized particles of tribochemical silica coating-treated surface. We hypothesize that ultrasonic cleaning of bonding surfaces, which were pretreated with sandblasting, may affect adhesive strength of a resin luting material to dental restorative materials.We therefore observed adhesive strength of resin luting material to aluminum oxide was greater than those to zirconia ceramic and cobalt-chromium alloy beforehand. To measure the shear bond strengths of resin luting material to zirconia ceramic and cobalt-chromium alloy, forty specimens of each restorative material were prepared. Bonding surfaces were polished with silicon abrasive paper and then treated with sandblasting. For each restorative material, 40 sandblasted specimens were equally divided into two groups: ultrasonic cleaning (USC group and non-ultrasonic cleaning (NUSC group. After resin luting material was polymerized on bonding surface, shear test was performed to evaluate effect of ultrasonic cleaning of bonding surfaces pretreated with sandblasting on bond strength.For both zirconia ceramic and cobalt-chromium alloy, NUSC group showed significantly higher shear bond strength than USC group.Ultrasonic cleaning of dental restorations after sandblasting should be avoided to retain improved bonding between these materials.

  3. Role of dental restoration materials in oral mucosal lichenoid lesions

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    Rajneesh Sharma

    2015-01-01

    Full Text Available Background: Dental restorative materials containing silver-mercury compounds have been known to induce oral lichenoid lesions. Objectives: To determine the frequency of contact allergy to dental restoration materials in patients with oral lichenoid lesions and to study the effect of removal of the materials on the lesions. Results: Forty-five patients were recruited in three groups of 15 each: Group A (lesions in close contact with dental materials, Group B (lesions extending 1 cm beyond the area of contact and Group C (no topographic relationship. Thirty controls were recruited in two groups of 15 individuals each: Group D (oral lichenoid lesions but no dental material and Group E (dental material but no oral lichenoid lesions. Patch tests were positive in 20 (44.5% patients. Mercury was the most common allergen to elicit a positive reaction in eight patients, followed by nickel (7, palladium (5, potassium dichromate (3, balsam of Peru, gold sodium thiosulphate 2 and tinuvin (2 and eugenol (1, cobalt chloride (1 and carvone (1. Seven patients elicited positive response to more than one allergen. In 13 of 20 patients who consented to removal of the dental material, complete healing was observed in 6 (30%, marked improvement in 7 (35% and no improvement in 7 (35% patients. Relief of symptoms was usually observed 3 months after removal. Limitations: Limited number of study subjects and short follow up after removal/replacement of dental restoration materials are the main limitations of this study. Conclusion: Contact allergy to amalgam is an important etiologic factor in oral lichenoid lesions and removal of restorative material should be offered to patients who have lesions in close proximity to the dental material.

  4. Recent advances and developments in composite dental restorative materials.

    Science.gov (United States)

    Cramer, N B; Stansbury, J W; Bowman, C N

    2011-04-01

    Composite dental restorations represent a unique class of biomaterials with severe restrictions on biocompatibility, curing behavior, esthetics, and ultimate material properties. These materials are presently limited by shrinkage and polymerization-induced shrinkage stress, limited toughness, the presence of unreacted monomer that remains following the polymerization, and several other factors. Fortunately, these materials have been the focus of a great deal of research in recent years with the goal of improving restoration performance by changing the initiation system, monomers, and fillers and their coupling agents, and by developing novel polymerization strategies. Here, we review the general characteristics of the polymerization reaction and recent approaches that have been taken to improve composite restorative performance.

  5. Backscattering from dental restorations and splint materials during therapeutic radiation

    International Nuclear Information System (INIS)

    Farman, A.G.; Sharma, S.; George, D.I.; Wilson, D.; Dodd, D.; Figa, R.; Haskell, B.

    1985-01-01

    Models were constructed to simulate as closely as possible the human oral cavity. Radiation absorbed doses were determined for controls and various test situations involving the presence of dental restorative and splint materials during cobalt-60 irradiation of the models. Adjacent gold full crowns and adjacent solid dental silver amalgam cores both increased the dose to the interproximal gingivae by 20%. Use of orthodontic full bands for splinting the jaws increased the dose to the buccal tissues by an average of 10%. Augmentation of dose through backscatter radiation was determined to be only slight for intracoronal amalgam fillings and stainless steel or plastic bracket splints

  6. Evaluation of radiation effects on dental enamel hardness and dental restorative materials

    International Nuclear Information System (INIS)

    Adachi, Lena Katekawa; Saiki, Mitiko; Campos, Tomie Nakakuki

    2000-01-01

    This research presents the results of the microhardness of human dental enamel and of the following dental restorative materials: three dental porcelains - Ceramco II, Finesse and Noritake, and two resin restorative materials - Artglass and Targis, for materials submitted to different times of irradiation at the IEA-R1m nuclear reactor under a thermal neutron flux of 10 12 n cm -2 .s -1 . The results obtained indicated that there is a decrease of the surface microhardness when the enamel is irradiated for 1 h and when dental materials are irradiated for 3 h. However, enamels irradiated for 30 min. did not show significant change of their surface hardness. Therefore, the selection of irradiation time is an important factor to be considered when irradiated teeth or dental materials are used in the investigations of their properties. (author)

  7. Interpenetrating network ceramic-resin composite dental restorative materials.

    Science.gov (United States)

    Swain, M V; Coldea, A; Bilkhair, A; Guess, P C

    2016-01-01

    This paper investigates the structure and some properties of resin infiltrated ceramic network structure materials suitable for CAD/CAM dental restorative applications. Initially the basis of interpenetrating network materials is defined along with placing them into a materials science perspective. This involves identifying potential advantages of such structures beyond that of the individual materials or simple mixing of the components. Observations from a number of recently published papers on this class of materials are summarized. These include the strength, fracture toughness, hardness and damage tolerance, namely to pointed and blunt (spherical) indentation as well as to burr adjustment. In addition a summary of recent results of crowns subjected to simulated clinical conditions using a chewing simulator are presented. These results are rationalized on the basis of existing theoretical considerations. The currently available ceramic-resin IPN material for clinical application is softer, exhibits comparable strength and fracture toughness but with substantial R-curve behavior, has lower E modulus and is more damage tolerant than existing glass-ceramic materials. Chewing simulation observations with crowns of this material indicate that it appears to be more resistant to sliding/impact induced cracking although its overall contact induced breakage load is modest. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  8. Evaluation of patients with oral lichenoid lesions by dental patch testing and results of removal of the dental restoration material

    Directory of Open Access Journals (Sweden)

    Emine Buket Şahin

    2016-12-01

    Full Text Available Background and Design: Oral lichenoid lesions (OLL are contact stomatitis characterized by white reticular or erosive patches, plaque-like lesions that are clinically and histopathologically indistinguishable from oral lichen planus (OLP. Amalgam dental fillings and dental restoration materials are among the etiologic agents. In the present study, it was aimed to evaluate the standard and dental series patch tests in patients with OLL in comparison to a control group and evaluate our results. Materials and Methods: Thirty-three patients with OLL or OLP and 30 healthy control subjects, who had at least one dental restoration material and/or dental filling, were included in the study. Both groups received standard series and dental patch test and the results were evaluated simultaneously. Results: The most frequent allergens in the dental series patch test in the patient group were palladium chloride (n=4; 12.12% and benzoyl peroxide (n=2, 6.06%. Of the 33 patients with OLL; 8 had positive reaction to allergents in the standard patch test series and 8 had positive reaction in the dental patch test series. There was no significant difference in the rate of patch test reaction to the dental and standard series between the groups. Ten patients were advised to have the dental restoration material removed according to the results of the patch tests. The lesions improved in three patients [removal of all amalgam dental fillings (n=1, replacement of all amalgam dental fillings with an alternative filling material (n=1 and replacement of the dental prosthesis (n=1] following the removal or replacement of the dental restoration material. Conclusion: Dental patch test should be performed in patients with OLL and dental restoration material. Dental filling and/or prosthesis should be removed/replaced if there is a reaction against a dental restoration material-related allergen.

  9. Machinable glass-ceramics forming as a restorative dental material.

    Science.gov (United States)

    Chaysuwan, Duangrudee; Sirinukunwattana, Krongkarn; Kanchanatawewat, Kanchana; Heness, Greg; Yamashita, Kimihiro

    2011-01-01

    MgO, SiO(2), Al(2)O(3), MgF(2), CaF(2), CaCO(3), SrCO(3), and P(2)O(5) were used to prepare glass-ceramics for restorative dental materials. Thermal properties, phases, microstructures and hardness were characterized by DTA, XRD, SEM and Vickers microhardness. Three-point bending strength and fracture toughness were applied by UTM according to ISO 6872: 1997(E). XRD showed that the glass crystallized at 892°C (second crystallization temperature+20°C) for 3 hrs consisted mainly of calcium-mica and fluorapatite crystalline phases. Average hardness (3.70 GPa) closely matched human enamel (3.20 GPa). The higher fracture toughness (2.04 MPa√m) combined with the hardness to give a lower brittleness index (1.81 µm(-1/2)) which indicates that they have exceptional machinability. Bending strength results (176.61 MPa) were analyzed by Weibull analysis to determine modulus value (m=17.80). Machinability of the calcium mica-fluorapatite glass-ceramic was demonstrated by fabricating with CAD/CAM.

  10. A useful and non-invasive microanalysis method for dental restoration materials

    Science.gov (United States)

    Hosoki, M.; Satsuma, T.; Nishigawa, K.; Takeuchi, H.; Asaoka, K.

    2012-12-01

    The elemental analysis of intraoral dental restorations provides considerable information for the treatment of dental metal allergy. Elemental analyses require specific instruments and complicated procedures, so this examination is not commonly carried out in private dental clinics. We describe a novel, simple and useful micro-analytical method for dental metal restorations. Micro metal dust was obtained by polishing the surface of restorative metal material with an unused silicone point (SUPER-SNAP). The metal dust on the silicone point was then rubbed onto adhesive tape, and this tape was covered with polyethylene film. The amount of metal dust material was film. Three types of dental metal alloy materials of known components were examined. The results of elementary analyses were compared with the specifications provided by the manufacturer. The same procedure was carried out for three dental metal restorations of an adult female volunteer in vivo. The results of elemental analyses for five alloy materials exactly matched the product specification. Three metal samples obtained from intraoral restoration were also available for elemental analyses. The distinct advantage of this method is that it enables sample extraction without an invasive effect for the restoration. The metal sample is in a polyethylene film, so it is easy to mail it for inspection at specialist institutes yet it can be also be used in general dental clinics.

  11. A useful and non-invasive microanalysis method for dental restoration materials

    International Nuclear Information System (INIS)

    Hosoki, M.; Satsuma, T.; Nishigawa, K.; Takeuchi, H.; Asaoka, K.

    2012-01-01

    Highlights: ► This method for the microanalysis of dental alloys is beneficial for patients with allergies to dental materials. ► This metal sample is easy to mail it for inspection at specialist institutes. ► This method can be also be used in general dental clinics. - Abstract: The elemental analysis of intraoral dental restorations provides considerable information for the treatment of dental metal allergy. Elemental analyses require specific instruments and complicated procedures, so this examination is not commonly carried out in private dental clinics. We describe a novel, simple and useful micro-analytical method for dental metal restorations. Micro metal dust was obtained by polishing the surface of restorative metal material with an unused silicone point (SUPER-SNAP). The metal dust on the silicone point was then rubbed onto adhesive tape, and this tape was covered with polyethylene film. The amount of metal dust material was <20 μg. An energy dispersive X-ray fluorescence spectrometer was used to carry out the elementary analysis of the metal dust on the polyethylene film. Three types of dental metal alloy materials of known components were examined. The results of elementary analyses were compared with the specifications provided by the manufacturer. The same procedure was carried out for three dental metal restorations of an adult female volunteer in vivo. The results of elemental analyses for five alloy materials exactly matched the product specification. Three metal samples obtained from intraoral restoration were also available for elemental analyses. The distinct advantage of this method is that it enables sample extraction without an invasive effect for the restoration. The metal sample is in a polyethylene film, so it is easy to mail it for inspection at specialist institutes yet it can be also be used in general dental clinics.

  12. A useful and non-invasive microanalysis method for dental restoration materials

    Energy Technology Data Exchange (ETDEWEB)

    Hosoki, M., E-mail: hosoki@tokushima-u.ac.jp [Department of Fixed Prosthodontics, Institute of Health Biosciences, University of Tokushima Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8504 (Japan); Satsuma, T.; Nishigawa, K.; Takeuchi, H. [General Dentistry, Tokushima University Hospital, 3-18-15 Kuramoto-cho, Tokushima 770-8504 (Japan); Asaoka, K. [Department of Biomaterials and Bioengineering, Institute of Health Biosciences, University of Tokushima Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8504 (Japan)

    2012-12-01

    Highlights: Black-Right-Pointing-Pointer This method for the microanalysis of dental alloys is beneficial for patients with allergies to dental materials. Black-Right-Pointing-Pointer This metal sample is easy to mail it for inspection at specialist institutes. Black-Right-Pointing-Pointer This method can be also be used in general dental clinics. - Abstract: The elemental analysis of intraoral dental restorations provides considerable information for the treatment of dental metal allergy. Elemental analyses require specific instruments and complicated procedures, so this examination is not commonly carried out in private dental clinics. We describe a novel, simple and useful micro-analytical method for dental metal restorations. Micro metal dust was obtained by polishing the surface of restorative metal material with an unused silicone point (SUPER-SNAP). The metal dust on the silicone point was then rubbed onto adhesive tape, and this tape was covered with polyethylene film. The amount of metal dust material was <20 {mu}g. An energy dispersive X-ray fluorescence spectrometer was used to carry out the elementary analysis of the metal dust on the polyethylene film. Three types of dental metal alloy materials of known components were examined. The results of elementary analyses were compared with the specifications provided by the manufacturer. The same procedure was carried out for three dental metal restorations of an adult female volunteer in vivo. The results of elemental analyses for five alloy materials exactly matched the product specification. Three metal samples obtained from intraoral restoration were also available for elemental analyses. The distinct advantage of this method is that it enables sample extraction without an invasive effect for the restoration. The metal sample is in a polyethylene film, so it is easy to mail it for inspection at specialist institutes yet it can be also be used in general dental clinics.

  13. Quantification of Staphylococcus aureus adhesion forces on various dental restorative materials using atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Merghni, Abderrahmen, E-mail: abderrahmen_merghni@yahoo.fr [Laboratoire des Maladies Transmissibles et Substances biologiquement actives (LR99ES27) Faculté de Pharmacie de Monastir, Université de Monastir (Tunisia); Kammoun, Dorra [Laboratoire de Biomatériaux et Biotechnologie, Faculté de Médecine Dentaire, Monastir (Tunisia); Hentati, Hajer [Laboratoire de Recherche en Santé Orale et Réhabilitation Bucco-Faciale (LR12ES11), Faculté de Médecine Dentaire de Monastir, Université de Monastir (Tunisia); Janel, Sébastien [BioImaging Center Lille-FR3642, Lille (France); Popoff, Michka [Cellular Microbiology and Physics of Infection-CNRS UMR8204, INSERM U1019, Institut Pasteur de Lille, Lille University (France); Lafont, Frank [BioImaging Center Lille-FR3642, Lille (France); Cellular Microbiology and Physics of Infection-CNRS UMR8204, INSERM U1019, Institut Pasteur de Lille, Lille University (France); Aouni, Mahjoub [Laboratoire des Maladies Transmissibles et Substances biologiquement actives (LR99ES27) Faculté de Pharmacie de Monastir, Université de Monastir (Tunisia); Mastouri, Maha [Laboratoire des Maladies Transmissibles et Substances biologiquement actives (LR99ES27) Faculté de Pharmacie de Monastir, Université de Monastir (Tunisia); Laboratoire de Microbiologie, CHU Fattouma Bourguiba de Monastir (Tunisia)

    2016-08-30

    Highlights: • 4 dental restorative materials were characterized for roughness, angle contact water and surface free energy. • AFM adhesion forces of S. aureus to tested materials were achieved in presence and absence of salivary conditioning film. • S. aureus initial adhesion is dependent on the surface free energy and roughness. - Abstract: In the oral cavity dental restorative biomaterials can act as a reservoir for infection with opportunistic Staphylococcus aureus pathogen, which can lead to the occurrence of secondary caries and treatment failures. Our aim was to evaluate the adhesion forces by S. aureus on four dental restorative biomaterials and to correlate this finding to differences in specific surface characteristics. Additionally, the influence of salivary conditioning films in exerted adhesion forces was investigated. The substrate hydrophobicity was measured by goniometer and the surface free energy was calculated using the equilibrium advancing contact angle values of water, formamide, and diiodomethane on the tested surfaces. The surface roughness was determined using atomic force microscope (AFM). Additionally, cell force spectroscopy was achieved to quantify the forces that drive cell-substrate interactions. S. aureus bacterium exerted a considerable adhesion forces on various dental restorative materials, which decreased in the presence of saliva conditioning film. The influence of the surface roughness and free energy in initial adhesion appears to be more important than the effect of hydrophobicity, either in presence or absence of saliva coating. Hence, control of surface properties of dental restorative biomaterials is of crucial importance in preventing the attachment and subsequent the biofilm formation.

  14. Quantification of Staphylococcus aureus adhesion forces on various dental restorative materials using atomic force microscopy

    International Nuclear Information System (INIS)

    Merghni, Abderrahmen; Kammoun, Dorra; Hentati, Hajer; Janel, Sébastien; Popoff, Michka; Lafont, Frank; Aouni, Mahjoub; Mastouri, Maha

    2016-01-01

    Highlights: • 4 dental restorative materials were characterized for roughness, angle contact water and surface free energy. • AFM adhesion forces of S. aureus to tested materials were achieved in presence and absence of salivary conditioning film. • S. aureus initial adhesion is dependent on the surface free energy and roughness. - Abstract: In the oral cavity dental restorative biomaterials can act as a reservoir for infection with opportunistic Staphylococcus aureus pathogen, which can lead to the occurrence of secondary caries and treatment failures. Our aim was to evaluate the adhesion forces by S. aureus on four dental restorative biomaterials and to correlate this finding to differences in specific surface characteristics. Additionally, the influence of salivary conditioning films in exerted adhesion forces was investigated. The substrate hydrophobicity was measured by goniometer and the surface free energy was calculated using the equilibrium advancing contact angle values of water, formamide, and diiodomethane on the tested surfaces. The surface roughness was determined using atomic force microscope (AFM). Additionally, cell force spectroscopy was achieved to quantify the forces that drive cell-substrate interactions. S. aureus bacterium exerted a considerable adhesion forces on various dental restorative materials, which decreased in the presence of saliva conditioning film. The influence of the surface roughness and free energy in initial adhesion appears to be more important than the effect of hydrophobicity, either in presence or absence of saliva coating. Hence, control of surface properties of dental restorative biomaterials is of crucial importance in preventing the attachment and subsequent the biofilm formation.

  15. SU-E-T-89: Characterization of Dental Restoration Material for Cs-137 Radiation Dosimetry.

    Science.gov (United States)

    Ratliff, S; Gustafson, B; Barry, K

    2012-06-01

    The purpose of this work is to characterize the radiation-induced thermoluminescence properties of a dental restoration material and to see if the material might be feasible for use in retrospective radiation dosimetry. Retrospective, or accidental, dosimetry is the study of using nearby materials to measure radiation received by individuals. In this project we obtained samples of Ivoclar Vivadent e.max CAD material, a glass-ceramic used for making dental restorations such as full or partial crowns. The samples were machined into square chips .32 cm × .32 cm × .089 cm and annealed in the same furnace used by the dentist. The samples were exposed to a Cs-137 source using a PMMA source holder and then read in a Harshaw 3500 TLD reader. The samples were read without nitrogen gas flux using heating rates of 5 degrees C/s or 10 degrees C/s up to a maximum temperature of 400 degrees Celsius. The glow curves were analyzed using Systat PeakFIT peak-fitting software and Microsoft Excel spreadsheets. The authors gratefully thank Dr. Aaron Imdieke and the staff of River City Dental, St. Cloud, MN for the dental restoration materials and the use of their dental furnace. A sample subjected to a radiation exposure of .04 C/kg exhibits a glow curve with a prominent peak at approximately 140 degrees Celsius, which is well-modeled by the first order glow curve deconvolution formula developed by Kitis, Gomez-Ros, and Tuyn. The activation energy corresponding to this peak is approximately 1 eV. The thermoluminescent signal fades with time after exposure. Ivoclar Vivadent e.max CAD dental restoration material has the potential to be used as a material for retrospective Cs-137 radiation dosimetry. Future work could look at its thermoluminescent dosimetry properties in more detail and also at other dental restoration materials. The authors would like to thank Dr. Aaron Imdieke and the staff of River City Dental, St. Cloud, MN, for the donation of scrap dental restoration materials and

  16. Fluoride release and recharge abilities of contemporary fluoride-containing restorative materials and dental adhesives.

    Science.gov (United States)

    Dionysopoulos, Dimitrios; Koliniotou-Koumpia, Eugenia; Helvatzoglou-Antoniades, Maria; Kotsanos, Nikolaos

    2013-01-01

    The aim of this study was to evaluate the fluoride release of five fluoride-releasing restorative materials and three dental adhesives, before and after NaF solution treatment. Five restorative materials (Fuji IX GP, GC Corp.; Ketac N100, 3M ESPE; Dyract Extra, Dentsply; Beautifil II, Shofu Inc.; Wave, SDI) and three dental adhesives (Stae, SDI; Fluorobond II - Shofu Inc.; Prime & Bond NT, Dentsply) were investigated before and after NaF solution treatment. A fluoride ion-selective electrode was to measure fluoride concentrations. During the 86-day period before NaF solution treatment, Fuji IX GP released the highest amount of fluoride among the restorative materials while Prime & Bond NT was the highest among the dental adhesives. After NaF solution treatment, Fuji IX GP again ranked the highest in fluoride release among the restorative materials while Fluorobond II ranked the highest among dental adhesives. It was concluded that the compositions and setting mechanisms of fluoride-containing dental materials influenced their fluoride release and recharge abilities.

  17. Effect of dental restorative materials on total antioxidant capacity and calcium concentration of unstimulated saliva.

    Science.gov (United States)

    Ramezani, Gholam H; Moghadam, Mona-Momeni; Saghiri, Mohammad-Ali; Garcia-Godoy, Franklin; Asatourian, Armen; Aminsobhani, Mohsen; Scarbecz, Mark; Sheibani, Nader

    2017-01-01

    To evaluate the effect of dental amalgam and composite restorations on total antioxidant capacity (TAC) and calcium (Ca) ion concentration of unstimulated saliva. Forty-eight children aged 6-10 years selected and divided into three groups of sixteen (8 males, 8 females). In group A and B, samples consisted of two class II dental composite or amalgam restorations, while in group C samples were caries-free (control group). Unstimulated saliva from all samples was collected and TAC was measured by spectrophotometry using an adaptation of 2, 2'-azino-di-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) assay. The Ca ion level was estimated by an auto- analyzer. Data were analyzed with one- and two-way ANOVA test, at a p difference between groups ( p differences within and between groups ( p Gender is an effective factor in changes induced in oral cavity as females showed more emphatic reaction to dental filling materials than males. Patients who have dental restorations, especially dental composites, should pay more attention to their dental hygiene, because dental restorations can increase oxidative stress and decrease Ca ion level in saliva, which might jeopardize remineralization process of tooth structures after demineralization. Key words: Amalgam, caries, composite, saliva, total antioxidant capacity.

  18. Evaluation of radiation effects on dental enamel hardness and dental restorative materials; Avaliacao do efeito da irradiacao na dureza do esmalte dental e de materiais odontologicos

    Energy Technology Data Exchange (ETDEWEB)

    Adachi, Lena Katekawa; Saiki, Mitiko [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Supervisao de Radioquimica; Campos, Tomie Nakakuki [Sao Paulo Univ., SP (Brazil). Faculdade de Odontologia. Dept. de Protese

    2000-07-01

    This research presents the results of the microhardness of human dental enamel and of the following dental restorative materials: three dental porcelains - Ceramco II, Finesse and Noritake, and two resin restorative materials - Artglass and Targis, for materials submitted to different times of irradiation at the IEA-R1m nuclear reactor under a thermal neutron flux of 10{sup 12}n cm{sup -2}.s{sup -1} . The results obtained indicated that there is a decrease of the surface microhardness when the enamel is irradiated for 1 h and when dental materials are irradiated for 3 h. However, enamels irradiated for 30 min. did not show significant change of their surface hardness. Therefore, the selection of irradiation time is an important factor to be considered when irradiated teeth or dental materials are used in the investigations of their properties. (author)

  19. Fluoride uptake from restorative dental materials by human enamel

    International Nuclear Information System (INIS)

    Forsten, L.; Rytoemaa, I.; Anttila, A.; Keinonen, J.

    1976-01-01

    The purpose of the study was to determine the uptake in vitro of fluoride from restorative materials by tooth enamel and whether prior etching of the enamel causes a change of uptake. The outermost layer of the labial surface of extracted canines was removed by grinding and the enamel was covered with five different fluoride-containing materials ; a silicate, a composite resin, an amalgam, a silicophosphate, and a polycarboxylate luting cement. The material was either removed immediately or after storing the tooth in distilled water. The fluoride content was determined using a sensitive physical method based on the 19 F (p, αγ) 16 O reaction. In addition, the fluoride content of enamel after etching for different periods of time and of etched enamel which had been in contact with silicate cement was determined. The mean fluoride content of uncovered interior enamel was 226 parts 10 6 . All materials, except the composite, increased clearly the fluoride content of the underlying enamel. Etching of interior enamel also increased the fluoride values. No difference could be shown in fluoride uptake from silicate and composite resin between etched and unetched enamel. (author)

  20. Opalescence of human teeth and dental esthetic restorative materials.

    Science.gov (United States)

    Lee, Yong-Keun

    2016-12-01

    Human tooth enamel is opalescent, which renders teeth bluish in reflected and orange in transmitted color. The aim was to review opalescent property of teeth and application and mimetic reproduction in esthetic restorations. A PubMed search for articles published in English till 2015 on the opalescence of teeth and esthetic materials revealed 29 relevant papers. Opalescence was measured with OP-RT index, which was calculated as the difference in the yellow-blue and red-green color coordinates between the reflected and transmitted colors. Mean OP-RT value of human enamel was 22.9. OP-RT values of direct resin composites changed after polymerization, and the range in these materials was 5.7-23.7. OP-RT value ranges were 1.6-6.1 and 2.0-7.1 for the core and veneer ceramics, respectively. Since the OP-RT values of esthetic materials were lower than that of enamel, it is recommended that materials that can reproduce the opalescence of enamel be further designed.

  1. Dental restorative materials from a work environmental perspective

    OpenAIRE

    Lönnroth, Emma-Christin

    1999-01-01

    The main occupational health hazard for dental personnel is muscle-skeletal problem, followed by symptoms caused by exposure to chemicals. Clinical dental work includes exposure to a number of products like soap, detergents, disinfectants, amalgam, mono- and oligomers, catalysts, inhibitors, solvents and adhesives. Some are chemically very active. The aims of this thesis have been to survey the occurrence of symptoms from skin, eyes and respiratory tract among dental personnel working in gene...

  2. Effect of Dental Restorative Material Type and Shade on Characteristics of Two-Layer Dental Composite Systems

    Directory of Open Access Journals (Sweden)

    Atefeh Karimzadeh

    Full Text Available Abstract The purpose of this study was to investigate the effects of shade and material type and shape in dental polymer composites on the hardness and shrinkage stress of bulk and two-layered restoration systems. For this purpose, some bulk and layered specimens from three different shades of dental materials were prepared and light-cured. The experiments were carried out on three types of materials: conventional restorative composite, nanohybrid composite and nanocomposite. Micro-indentation experiment was performed on the bulk and also on each layer of layered restoration specimens using a Vicker's indenter. The interface between the two layers was studied by scanning electron microscopy (SEM. The results revealed significant differences between the values of hardness for different shades in the conventional composite and also in the nanohybrid composite. However, no statistically significant difference was observed between the hardness values for different shades in the nanocomposite samples. The layered restoration specimens of different restorative materials exhibited lower hardness values with respect to their bulk specimens. The reduction in the hardness value of the layered conventional composite samples was higher than those of the nanocomposite and nanohybrid composite specimens indicating more shrinkage stresses generated in the conventional composite restorations. According to the SEM images, a gap was observed between the two layers in the layered restorations.

  3. Amino acid derivative-mediated detoxification and functionalization of dual cure dental restorative material for dental pulp cell mineralization.

    Science.gov (United States)

    Minamikawa, Hajime; Yamada, Masahiro; Iwasa, Fuminori; Ueno, Takeshi; Deyama, Yoshiaki; Suzuki, Kuniaki; Yawaka, Yasutaka; Ogawa, Takahiro

    2010-10-01

    Current dental restorative materials are only used to fill the defect of hard tissues, such as dentin and enamel, because of their cytotoxicity. Therefore, exposed dental pulp tissues in deep cavities must be first covered by a pulp capping material like calcium hydroxide to form a layer of mineralized tissue. However, this tissue mineralization is based on pathological reaction and triggers long-lasting inflammation, often causing clinical problems. This study tested the ability of N-acetyl cysteine (NAC), amino acid derivative, to reduce cytotoxicity and induce mineralized tissue conductivity in resin-modified glass ionomer (RMGI), a widely used dental restorative material having dual cure mechanism. Rat dental pulp cells were cultured on untreated or NAC-supplemented RMGI. NAC supplementation substantially increased the percentage of viable cells from 46.7 to 73.3% after 24-h incubation. Cell attachment, spreading, proliferative activity, and odontoblast-related gene and protein expressions increased significantly on NAC-supplemented RMGI. The mineralization capability of cells, which was nearly suppressed on untreated RMGI, was induced on NAC-supplemented RMGI. These improved behaviors and functions of dental pulp cells on NAC-supplemented RMGI were associated with a considerable reduction in the production of intracellular reactive oxygen species and with the increased level of intracellular glutathione reserves. These results demonstrated that NAC could detoxify and functionalize RMGIs via two different mechanisms involving in situ material detoxification and antioxidant cell protection. We believe that this study provides a new approach for developing dental restorative materials that enables mineralized tissue regeneration.

  4. An in vitro study of dental enamel wear by restorative materials using radiometric method

    International Nuclear Information System (INIS)

    Adachi, Lena Katekawa

    2000-01-01

    There is an increasing demand and interest to study the dental materials wear as well as about the abrasion effect on antagonistic teeth. Due to the fact that the existent restorative materials have no specifications about their abrasiveness, it is necessary the establishment of degrees of comparison among them to support clinical application. In this work, the radiometric method was applied to study the enamel wear caused by another enamel and by restorative materials (Ceramco II, Noritake and Finesse porcelains, Artglass and Targis). The dental enamel made radioactive by irradiation at the IEA-R1m nuclear research reactor under a thermal neutron flux was submitted to wear in a machine which allows sliding motion of an antagonistic surface in contact with this radioactive enamel. The enamel wear was evaluated by measuring beta activity of 32 P transferred to water from this irradiated tooth. Results obtained indicated that dental porcelains cause pronounced enamel wear when compared with that provoked by another enamel or by resin materials. Resin materials caused less enamel wear than another enamel. Vickers microhardness data obtained for antagonistic materials showed a correlation with the wear caused to the enamel. This study allowed to conclude that the radiometric method proposed can be used satisfactorily in the evaluation of enamel wear by restorative materials. This method presents advantages due to quick responses and ease of analyses There is (author)

  5. Biofilm Formation on Dental Restorative and Implant Materials

    NARCIS (Netherlands)

    Busscher, H. J.; Rinastiti, M.; Siswomihardjo, W.; van der Mei, H. C.

    Biomaterials for the restoration of oral function are prone to biofilm formation, affecting oral health. Oral bacteria adhere to hydrophobic and hydrophilic surfaces, but due to fluctuating shear, little biofilm accumulates on hydrophobic surfaces in vivo. More biofilm accumulates on rough than on

  6. An in vitro investigation of human enamel wear by restorative dental materials

    International Nuclear Information System (INIS)

    Adachi, L.K.; Saiki, M.; De Campos, T.N.

    2001-01-01

    A radiometric method was applied to asses enamel wear by another enamel and by restorative materials. The radioactive enamel was submitted to wear in a machine which allows sliding motion of an antagonistic surface in contact with the radioactive enamel. The enamel wear was evaluated by measuring the beta-activity of 32 P transferred to water from this irradiated tooth. Results obtained indicated that dental porcelains cause pronounced enamel wear when compared with that provoked by another natural enamel or by resin materials. Resin materials caused less enamel wear than another natural enamel. Vickers microhardness data obtained for antagonistic materials showed a correlation with the wear caused to the enamel. (author)

  7. Morphological characterization of ceramic fillers made from Indonesian natural sand as restorative dental materials

    Science.gov (United States)

    Karlina, E.; Susra, S.; Fatmala, Y.; Hartoyo, H. M.; Takarini, V.; Usri, K.; Febrida, R.; Djustiana, N.; Panatarani, C.; Joni, I. M.

    2018-02-01

    Dental composite as restorative dental materials can be reinforced using ceramic fillers. Homogeneous distribution of filler particles shall improve its mechanical properties. This paper presents the results of the preliminary study on the ZrO2-Al2O3-SiO2 ceramic fillers made from Indonesian natural sand that can increase the mechanical properties of dental composite. The synthesis was done using zirconium silicate sand (ZrSiO4) and aluminium oxide (Al2O3) precursors, which dissolved together with 70:30 weight ratios. Two types of sand were used: (1) manufactured sand (mesh #80) and (2) natural sand (mesh #400). The samples then heated in the furnace at 1100 °C for 8 hours. The morphological characterization was then evaluated using JEOL Scanning Electron Microscope (SEM) for the surface structure that analyze particles size and distribution. Ceramic fillers made from natural sand is homogenous, well distributed with average particle size of 5-10 µm. Comparably, ceramic filler made from the manufactured sand is heterogeneous, poorly distributed and appear as agglomerates with average particle size are 30-50 µm. The results suggest that ceramic fillers made from natural sand demonstrate better character to represent as a functional restorative dental material.

  8. The effect of bleaching agents on the microhardness of dental aesthetic restorative materials.

    Science.gov (United States)

    Türker, S B; Biskin, T

    2002-07-01

    This study investigated the effects of three home bleaching agents on the microhardness of various dental aesthetic restorative materials. The restorative materials were: feldspatic porcelain, microfilled composite resin and light-cured modified glass-ionomer cement and the bleaching agents Nite-White (16% carbamide peroxide), Opalescence (10% carbamide peroxide and carbapol jel) and Rembrandt (10% carbamide peroxide jel). A total of 90 restorative material samples were prepared 1 cm diameter and 6 mm thick and kept in distilled water for 24 h before commencing bleaching which was carried out for 8 h day-1 for 4 weeks. Microhardness measurements were then made using a Tukon tester. Statistically significant differences with respect to unbleached controls were found only for the feldspatic porcelain and microfilled composite resins (P light cured modified glass-ionomer cement. For the composite resin, whereas Nite-White increased its microhardness, the other bleaching agents decreased it. There were no significant differences between the bleaching agents for any of the restorative materials.

  9. Evaluation of effects of ionizing radiation on materials used in dental restorations

    International Nuclear Information System (INIS)

    Maio, Mireia Florencio

    2009-01-01

    This work consisted of quantitative studies of the effects caused by ionizing radiation on materials used in dental restorations (Titanium, Amalgam, Resin Composite and Glass Ionomer) aiming the deleterious effects of radiotherapy when patients with tumors in head and neck, arising when the teeth are restored within in the field of radiation. Samples were submitted to X-ray beams of 6 MV from a linear accelerator, VARIAN 2100C model. The samples were analyzed by X-ray fluorescence techniques to compare the chemical composition before and after the irradiation. The sample were submitted to Geiger-Mueller detectors and the ionization chambers in order to verify any residual radiation in the samples. The samples were also analyzed by gamma spectrometry by a Germanium detector. These tests were performed to determine small changes in the composition in the samples due to the radiation interaction. The results of this study may encourage the development of new research for alternative materials in dental restorations that can contribute to improve the quality of life of those patients with tumors of the mouth. (author)

  10. Nordic dentists' opinions on the safety of amalgam and other dental restorative materials.

    Science.gov (United States)

    Widström, E; Haugejorden, O; Sundberg, H; Birn, H

    1993-08-01

    The safety of amalgam and other restorative materials has caused concern among dental patients in recent years. The aim of this study was to obtain information on dentists' perceived competence in handling different filling materials and their opinions on the safety of these. A random sample of practising dentists in Denmark, Finland, Norway, and Sweden received a mail questionnaire in spring 1990. Answers were received from 1732 dentists (65%). The study showed that the respondents believed that their theoretic knowledge and clinical skills were generally at a high level regarding restorative materials. The risks of the side-effects of gold, ceramic materials, and glass ionomer were considered to be low by about 90% of the respondents. Amalgam was considered to be significantly more hazardous by the Swedish respondents than the others. Interestingly, composite was considered to be associated with a high risk of side-effects by about half of the dentists in all Nordic countries. The dentists' opinions were not found to be greatly influenced by their sex, age, or place of residence but rather by their country and service sector. Against the background of the present lack of scientific evidence on the hazardousness of amalgam or other restorative materials for patients' general health, these findings indicate that dentists are influenced by discussions in the mass media about dental treatment and materials and, of course, by the guidelines given by the health authorities in their own countries. Few dentists were shown to be concerned about occupational risks associated with the use of amalgam, and they had not had their own amalgam fillings replaced.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. A Deep Morphological Characterization and Comparison of Different Dental Restorative Materials

    Directory of Open Access Journals (Sweden)

    R. Condò

    2017-01-01

    Full Text Available Giomer is a relatively new class of restorative material with aesthetics, handling and physical properties of composite resins, and benefits of glass ionomers: high radiopacity, antiplaque effect, fluoride release, and recharge. To verify the superior properties of Giomers, in this study, a deep morphological characterization has been performed with an in vitro comparative study among a Giomer (Beautifil® II by Shofu Dental Corporation, Osaka, Japan, a Compomer (Dyract Extra by Dentsply, Caulk, Germany, glass ionomer cement (Ketac fil plus by 3M ESPE, and a composite resin (Tetric Evoceram by Ivoclar. In particular, mechanical and optical properties and ageing effects have been compared to investigate materials similarities and differences. Indentation tests, UV-Visible spectroscopy, Raman spectroscopy, and weight loss after storage in saliva or sugary drink have been carried out to analyze materials behavior in real conditions. The results confirm the high quality of Giomer material and indicate possible improvements in their usage.

  12. Effects of hydrogen peroxide bleaching strip gels on dental restorative materials in vitro: surface microhardness and surface morphology.

    Science.gov (United States)

    Duschner, Heinz; Götz, Hermann; White, Donald J; Kozak, Kathleen M; Zoladz, James R

    2004-01-01

    This study examined the effects of peroxide tooth bleaching, including Crest Whitestrips hydrogen peroxide gel treatments, on the surface hardness and morphology of common dental restorative treatments. American Dental Association (ADA) recommended dental restorative materials, including amalgam, dental gold, porcelain, glass ionomer, and composites, were prepared according to manufacturers' instructions. A cycling treatment methodology was employed which alternated ex vivo human salivary exposures with bleaching treatments under conditions of controlled temperature and durations of treatment. Bleaching treatments included commercial Crest Whitestrips bleaching gels, which utilize hydrogen peroxide as the in situ bleaching source, and several commercial carbamide peroxide bleaching gels. Control treatments included placebo gels and an untreated group. Crest Whitestrips bleaching included treatment exposures simulating recommended clinical exposures (14 hours), along with excess bleaching simulating exposure to five times suggested Crest Whitestrips use. At the conclusion of treatments, surface microhardness measures and surface morphological assessments with standard and variable pressure (VP-) SEMs were conducted to assess the effects of bleaching exposure on the surface morphology and structural integrity of the restoratives. Surface microhardness and SEM measures revealed no significant deleterious effects on the restoration surfaces from Whitestrips gels. These results confirm that tooth bleaching from the selected commercial hydrogen peroxide or carbamide peroxide bleaching systems does not produce changes in surface morphology or microhardness of common dental restorative materials. These results support the clinical safety of the selected commercial bleaching systems to the oral environment, matching results obtained from long-term use of these ingredients applied in dental offices and available in commercial formulations.

  13. Mechanical properties and three-body wear of dental restoratives and their comparative flowable materials.

    Science.gov (United States)

    Schultz, Sabine; Rosentritt, Martin; Behr, Michael; Handel, Gerhard

    2010-01-01

    To compare wear performance and resistance to crack propagation (K1C) of commercial restorative materials and their flowable variations. A potential correlation between three-body wear and fracture toughness, modulus of elasticity, fracture work, Vickers hardness, and filler content was investigated. Seven restoratives (five composites, one ormocer, and one compomer) and their corresponding flowable materials were used to determine and compare the three-body wear with a bolus of millet-seed shells and rice food (Willytec). The wear characteristics were measured by profilometry after 50,000, 100,000, 150,000, and 200,000 loading cycles. The fracture toughness value, K1C (MPam1/2), for each single-edged notched specimen was measured in a three-point bending test (universal testing machine 1446, Zwick). Fracture work and modulus of elasticity were calculated from the load curves. Vickers hardness was measured (HV hardness tester, Zwick) according to DIN 50133. The veneering composite Sinfony (3M ESPE) was used as a reference material. Heavily filled composites experienced less wear than their flowable variations. The nanofiller composites revealed better wear results than hybrid composites, compomers, and ormocers. After 200,000 load cycles, the lowest wear rates were detected for Grandio (14 microm; Voco), and the highest mean values were found for Dyract AP (104 microm; Dentsply DeTrey). The values for fracture toughness (K1C) ranged from 0.82 to 3.64 MPam1/2. Highest K1C data was exhibited by the nanocomposite Nanopaq (Schutz Dental). All tested restorative materials exhibited higher fracture toughness than their low-viscosity variations. The wear resistance of the newer generation composites with incorporated nanofiller or microfiller particles increased to a high extent. Flowables show less resistance against wear and crack propagation because of their lower filler content. The reduced mechanical properties limit their use as a restorative to small noncontact

  14. Matching the optical properties of direct esthetic dental restorative materials to those of human enamel and dentin

    Science.gov (United States)

    Ragain, James Carlton, Jr.

    One of the goals of the restorative dentist is to restore the appearance of the natural dentition. Clinical matching of teeth and restorative materials are seldom accurate and shade selection techniques are subjective. The first specific aim of this research was to characterize the optical absorption and scattering that occurs within enamel, dentin, and composite resin and compomer restorative materials and to relate those phenomena to translucency and color. The second aim was to evaluate small color differences among composite restorative materials which would be detectable by humans. The last aim was to lay the foundation for developing an improved model of specifying layers of dental restorative materials in order to match the translucency and color to those of human enamel. The Kubelka-Munk theory was validated for enamel, dentin, and the restorative materials. These tissues and materials were then characterized in terms of their color parameters. Tooth cores were also characterized in terms of color space parameters. Human subjects were evaluated for their abilities to discriminate small color differences in the dental composite resin materials. The following conclusions were derived from this study: (1) Kubelka-Munk theory accurately predicts the diffuse reflectance spectra of enamel, dentin, and the direct esthetic dental restorative materials studied. (2) Scattering and absorption coefficients of the dental tissues and esthetic restorative materials can be directly calculated from diffuse reflectance measurements of a uniformly thick slab of tissue/material using black and white backings and the appropriate refractive index. (3) For tooth cores, there is a positive correlation between L* and b* and a negative correlation between L* and a*. (4) The range of translucency parameters for the restorative materials studied does not match those of enamel and dentin. (5) None of the shades of the dental composite resin restorative materials studied fit into the

  15. Ultrashort pulse laser processing of hard tissue, dental restoration materials, and biocompatibles

    Science.gov (United States)

    Yousif, A.; Strassl, M.; Beer, F.; Verhagen, L.; Wittschier, M.; Wintner, E.

    2007-07-01

    During the last few years, ultra-short laser pulses have proven their potential for application in medical tissue treatment in many ways. In hard tissue ablation, their aptitude for material ablation with negligible collateral damage provides many advantages. Especially teeth representing an anatomically and physiologically very special region with less blood circulation and lower healing rates than other tissues require most careful treatment. Hence, overheating of the pulp and induction of microcracks are some of the most problematic issues in dental preparation. Up till now it was shown by many authors that the application of picosecond or femtosecond pulses allows to perform ablation with very low damaging potential also fitting to the physiological requirements indicated. Beside the short interaction time with the irradiated matter, scanning of the ultra-short pulse trains turned out to be crucial for ablating cavities of the required quality. One main reason for this can be seen in the fact that during scanning the time period between two subsequent pulses incident on the same spot is so much extended that no heat accumulation effects occur and each pulse can be treated as a first one with respect to its local impact. Extension of this advantageous technique to biocompatible materials, i.e. in this case dental restoration materials and titanium plasma-sprayed implants, is just a matter of consequence. Recently published results on composites fit well with earlier data on dental hard tissue. In case of plaque which has to be removed from implants, it turns out that removal of at least the calcified version is harder than tissue removal. Therefore, besides ultra-short lasers, also Diode and Neodymium lasers, in cw and pulsed modes, have been studied with respect to plaque removal and sterilization. The temperature increase during laser exposure has been experimentally evaluated in parallel.

  16. Comparison of chemical composition of materials used in dental restorations 08 years after the irradiation

    International Nuclear Information System (INIS)

    Maio, Mireia Florencio; Santos, Adimir dos; Fernandes, Marco A.R.

    2009-01-01

    The purpose of this work consisted of quantitative studies of the effects caused by ionizing radiation on the materials commonly used in dental restorations (amalgam, composite resin and Compomer), to mitigate the deleterious effects of radiotherapy when patients with tumors in head and neck, observed when the teeth are restored within the field of radiation. Samples were submitted to the beam of radiation from a source of cobalt-therapy, and analyzed by a X-ray fluorescence technique, by comparing the chemical composition of samples before and after irradiation. Gamma spectrometry was performed with detector of NaI and HPGe in the same samples. Then, the samples were kept in an appropriate place and after 08 years is repeated the same analysis. With these tests, it was possible to verify small changes in the composition of bodies of evidence due to the interaction 08 years after exposure to gamma radiation beams, simulating a patient who develops deleterious effects of radiation after the end radiotherapy treatment. (author)

  17. Comparison of chemical composition of materials used in dental restorations 08 years after the irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Maio, Mireia Florencio; Santos, Adimir dos, E-mail: mfmaio@ipen.b, E-mail: asantos@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP) Sao Paulo, SP (Brazil); Fernandes, Marco A.R., E-mail: marcosrf@salesiano-ata.b [UNESP, Botucatu, SP (Brazil). Faculdade de Medicina

    2009-07-01

    The purpose of this work consisted of quantitative studies of the effects caused by ionizing radiation on the materials commonly used in dental restorations (amalgam, composite resin and Compomer), to mitigate the deleterious effects of radiotherapy when patients with tumors in head and neck, observed when the teeth are restored within the field of radiation. Samples were submitted to the beam of radiation from a source of cobalt-therapy, and analyzed by a X-ray fluorescence technique, by comparing the chemical composition of samples before and after irradiation. Gamma spectrometry was performed with detector of NaI and HPGe in the same samples. Then, the samples were kept in an appropriate place and after 08 years is repeated the same analysis. With these tests, it was possible to verify small changes in the composition of bodies of evidence due to the interaction 08 years after exposure to gamma radiation beams, simulating a patient who develops deleterious effects of radiation after the end radiotherapy treatment. (author)

  18. Influence of different restorative materials on the stress distribution in dental implants.

    Science.gov (United States)

    Datte, Carlos-Eduardo; Tribst, João-Paulo-Mendes; Dal Piva, Amanda-Maria-de Oliveira; Nishioka, Renato-Sussumu; Bottino, Marco-Antonio; Evangelhista, Alexandre-Duarte M; Monteiro, Fabrício M de M; Borges, Alexandre-Luiz-Souto

    2018-05-01

    To assist clinicians in deciding the most suitable restorative materials to be used in the crowns and abutment in implant rehabilitation. For finite element analysis (FEA), a regular morse taper implant was created using a computer aided design software. The implant was inserted at the bone model with 3 mm of exposed threads. An anatomic prosthesis representing a first maxillary molar was modeled and cemented on the solid abutment. Considering the crown material (zirconia, chromium-cobalt, lithium disilicate and hybrid ceramic) and abutment (Titanium and zirconia), the geometries were multiplied, totaling eight groups. In order to perform the static analysis, the contacts were considered bonded and each material was assigned as isotropic. An axial load (200 N) was applied on the crown and fixation occurred on the base of the bone. Results using Von-Mises criteria and micro strain values were obtained. A sample identical to the CAD model was made for the Strain Gauge (SG) analysis; four SGs were bonded around the implant to obtain micro strain results in bone tissue. FEA results were 3.83% lower than SG. According to the crown material, it is possible to note that the increase of elastic modulus reduces the stress concentration in all system without difference for bone. Crown materials with high elastic modulus are able to decrease the stress values in the abutments while concentrates the stress in its structure. Zirconia abutments tend to concentrate more stress throughout the prosthetic system and may be more susceptible to mechanical problems than titanium. Key words: Finite element analysis, dental implants, ceramic.

  19. An in vitro study of dental enamel wear by restorative materials using radiometric method; Estudo in vitro do desgaste do esmalte dental pelos materiais restauradores utilizando metodo radiometrico

    Energy Technology Data Exchange (ETDEWEB)

    Adachi, Lena Katekawa

    2000-07-01

    There is an increasing demand and interest to study the dental materials wear as well as about the abrasion effect on antagonistic teeth. Due to the fact that the existent restorative materials have no specifications about their abrasiveness, it is necessary the establishment of degrees of comparison among them to support clinical application. In this work, the radiometric method was applied to study the enamel wear caused by another enamel and by restorative materials (Ceramco II, Noritake and Finesse porcelains, Artglass and Targis). The dental enamel made radioactive by irradiation at the IEA-R1m nuclear research reactor under a thermal neutron flux was submitted to wear in a machine which allows sliding motion of an antagonistic surface in contact with this radioactive enamel. The enamel wear was evaluated by measuring beta activity of {sup 32}P transferred to water from this irradiated tooth. Results obtained indicated that dental porcelains cause pronounced enamel wear when compared with that provoked by another enamel or by resin materials. Resin materials caused less enamel wear than another enamel. Vickers microhardness data obtained for antagonistic materials showed a correlation with the wear caused to the enamel. This study allowed to conclude that the radiometric method proposed can be used satisfactorily in the evaluation of enamel wear by restorative materials. This method presents advantages due to quick responses and ease of analyses There is (author)

  20. Shear bond strength of brackets on restorative materials: Comparison on various dental restorative materials using the universal primer Monobond® Plus.

    Science.gov (United States)

    Ebert, Thomas; Elsner, Laura; Hirschfelder, Ursula; Hanke, Sebastian

    2016-03-01

    The purpose of this work was to analyze surfaces consisting of different restorative materials for shear bond strength (SBS) and failure patterns of metal and ceramic brackets. Bonding involved the use of a universal primer (Monobond® Plus, Ivoclar Vivadent). Six restorative materials were tested, including one composite resin (Clearfil Majesty™ Posterior, Kuraray Noritake Dental), one glass-ceramic material (IPS Empress® Esthetic, Ivoclar Vivadent), one oxide-ceramic material (CORiTEC Zr transpa Disc, imes-icore), two base-metal alloys (remanium® star, Dentaurum; Colado® CC, Ivoclar Vivadent), and one palladium-based alloy (Callisto® 75 Pd, Ivoclar Vivadent). Bovine incisors served as controls. Both metal and ceramic brackets (discovery®/discovery® pearl; Dentaurum) were bonded to the restorative surfaces after sandblasting and pretreatment with Monobond® Plus. A setup modified from DIN 13990-2 was used for SBS testing and adhesive remnant index (ARI)-based analysis of failure patterns. The metal brackets showed the highest mean SBS values on the glass-ceramic material (68.61 N/mm(2)) and the composite resin (67.58 N/mm(2)) and the lowest mean SBS on one of the base-metal alloys (Colado® CC; 14.01 N/mm(2)). The ceramic brackets showed the highest mean SBS on the glass-ceramic material (63.36 N/mm(2)) and the lowest mean SBS on the palladium-based alloy (38.48 N/mm(2)). Significant differences between the metal and ceramic brackets were observed in terms of both SBS values and ARI scores (p bracket types, fractures of the composite-resin and the glass-ceramic samples were observed upon debonding. Opaque restorative materials under metal brackets were found to involve undercuring of the adhesive. Monobond® Plus succeeded in generating high bond strengths of both bracket types on all restorative surfaces. Given our observations of cohesive fracture (including cases of surface avulsion) of the composite-resin and the glass-ceramic samples, we recommend

  1. In Vitro Inhibition of Enamel Demineralisation by Fluoride-releasing Restorative Materials and Dental Adhesives.

    Science.gov (United States)

    Dionysopoulos, Dimitrios; Koliniotou-Koumpia, Eugenia; Helvatzoglou-Antoniades, Maria; Kotsanos, Nikolaos

    2016-01-01

    To determine the ability of 5 contemporary fluoride-releasing restoratives and 3 fluoride-releasing adhesives to inhibit enamel demineralisation surrounding restorations, and the associations between inhibition and the levels of fluoride released from these materials. Five fluoride-releasing restoratives (Fuji IX GP, Ketac N100, Dyract Extra, Beautifil II and Wave) and 3 fluoride-releasing adhesives (Stae, Prime & Bond NT and Fluoro Bond II) were investigated. Eight disks of each material were prepared. Fluoride release was measured daily using a fluoride-ion-selective electrode for 15 days. Twenty-four cavities for each group were restored with a restorative and an adhesive. Specimens were subjected to thermal stress and stored for 30 days in saline solution. After a 15-day pH-cycling regimen, two 150-μm-thick sections were derived from each specimen. Enamel lesion depth was measured at 0, 100, and 200 μm from each restoration's margin via polarised light microscopy. Of the restoratives investigated, Fuji IX GP released the most fluoride. The fluoride-releasing restoratives tested exhibited shallower enamel lesions than did the control group at all distances tested (p < 0.05). Fuji IX GP yielded significantly lower enamel lesion depth than did the other experimental materials. The depths of enamel lesions did not differ significantly when comparing restoratives applied with a fluoride-releasing adhesive with those applied with a non-fluoride-releasing adhesive. The fluoride-releasing materials tested reduced enamel demineralisation but to different extents, depending on their levels of fluoride release. Fluoride-releasing adhesives did not influence enamel lesion formation.

  2. Hydrogen peroxide bleaching induces changes in the physical properties of dental restorative materials: Effects of study protocols.

    Science.gov (United States)

    Yu, Hao; Zhang, Chang-Yuan; Wang, Yi-Ning; Cheng, Hui

    2018-03-01

    The purpose of this study was to evaluate the influence of study protocols on the effects of bleaching on the surface roughness, substance loss, flexural strength (FS), flexural modulus (FM), Weibull parameters, and color of 7 restorative materials. The test materials included 4 composite resins, 1 glass-ionomer cement, 1 dental ceramic, and 1 polyacid-modified composite. The specimens were randomly divided into 4 groups (n = 20) according to different study protocols: a bleaching group at 25°C (group 25B), a bleaching group at 37°C (group 37B), a control group at 25°C (group 25C), and a control group at 37°C (group 37C). The specimens in the bleaching group were treated with 40% hydrogen peroxide for 80 min at the respective environmental temperatures. The surface roughness, substance loss, FS, FM, and color of the specimens were measured before and after treatment. FS data were also subjected to Weibull analysis, which was used to estimate of the Weibull modulus (m) and the characteristic strength (σ 0 ). Surface roughness increased and significant color changes were observed for all tested specimens after bleaching treatment, except for the ceramic. After bleaching at 37°C, the polyacid-modified composite showed significantly reduced FS, FM, m, and σ 0 values in comparison to the control specimens stored at 37°C in whole saliva. Significant differences were also found between the 37B and 25B polyacid-modified composite groups in terms of surface roughness, FS, m, σ 0 , and color changes. Varying effects of bleaching on the physical properties of dental restorative materials were observed, and the influences of the study protocols on bleaching effects were found to be material-dependent. The influence of study protocols on the effects of bleaching on the surface roughness, flexural properties, and color of dental restorative materials are material-dependent and should be considered when evaluating the effects of bleaching on dental restorative

  3. Candida albicans adherence to resin-composite restorative dental material: influence of whole human saliva.

    Science.gov (United States)

    Maza, José Luis; Elguezabal, Natalia; Prado, Carlota; Ellacuría, Joseba; Soler, Iñaki; Pontón, José

    2002-11-01

    Attachment of Candida albicans to oral surfaces is believed to be a critical event in the colonization of the oral cavity and in the development of oral diseases such as Candida-associated denture stomatitis. Although there is considerable information about the adhesion of C albicans to buccal epithelial cells and prosthetic materials, there is very little information about the adhesion of C albicans to composite restorative materials. The purpose of this study was to investigate the degree of adhesion of C albicans to a resin-composite restorative material (Herculite). The adhesion of 2 strains of C albicans, a germinative and a germ tube-deficient mutant, was studied by a visual method after incubating the fungus and the resin with and without human whole saliva. In absence of saliva, the adhesion of the C albicans germinative isolate to the resin showed an increase in parallel with the germination, reaching a maximum at the end of the experiment (120 minutes). However, no significant differences were observed in the adhesion of the agerminative mutant during the period of time studied. In the presence of saliva, the adhesion of both isolates to the resin was significantly lowered. Germination and the presence of human whole saliva are important factors in the adhesion of C albicans to the resin-composite restorative material Herculite.

  4. Toxicity Testing of Restorative Dental Materials Using Brine Shrimp Larvae (Artemia salina

    Directory of Open Access Journals (Sweden)

    Manar M. Milhem

    2008-08-01

    Full Text Available This study investigated the effect of extracts of different composites, glass ionomer cement (GICs and compomers on the viability of brine shrimp larvae. Ethanolic extracts of four dental composites (Z-100; Solitaire 2; Filtek P60 and Synergy, a conventional GIC (Ketac-Fil, a resin-modified glass ionomer cement (Vitremer, two compomers (F2000; Dyract AP, and a flowable compomer (Dyract Flow were prepared from each material. Following evaporation of the ethanol, the extracts were resuspended in distilled water, which was then used to test the effects on the viability of brine shrimp larvae. For the composites, the extract of Synergy was the least toxic (88% viability followed by the extracts of Solitaire 2, Z100 and P60 (75%, 67.5% and 50% viability, respectively. One-way ANOVA revealed highly significant differences between the resin composite materials (p<0.001. Follow-up comparison between the composite groups by Tukey's pairwise multiple-comparison test (α =0.05 showed that the extract of Synergy was significantly less toxic than the extracts of all the other materials except that of Solitaire 2. The compomers showed 100% lethality, while the percentage of viable larvae for the extracts of Ketac-Fil, and Vitremer were 32.3%, and 37.0%, respectively. One-way ANOVA revealed highly significant differences between the groups of materials (p<0.001. Follow-up comparison between the groups by Tukey's test (α = 0.05 showed that the toxic effect of the extracts of the compomers were significantly greater than that of Ketac-Fil, and Vitremer. The differences in the toxic effects of Vitremer and Ketac-Fil were not statistically significant. In conclusion, the toxicity of composite materials varied according to their chemical composition. Compomers were the most lethal materials to brine shrimp larvae followed by GICs and then composites.

  5. Toxicity testing of restorative dental materials using brine shrimp larvae (Artemia salina).

    Science.gov (United States)

    Milhem, Manar M; Al-Hiyasat, Ahmad S; Darmani, Homa

    2008-01-01

    This study investigated the effect of extracts of different composites, glass ionomer cement (GIC)s and compomers on the viability of brine shrimp larvae. Ethanolic extracts of four dental composites (Z-100; Solitaire 2; Filtek P60 and Synergy), a conventional GIC (Ketac-Fil), a resin-modified glass ionomer cement (Vitremer), two compomers (F2000; Dyract AP), and a flowable compomer (Dyract Flow) were prepared from each material. Following evaporation of the ethanol, the extracts were resuspended in distilled water, which was then used to test the effects on the viability of brine shrimp larvae. For the composites, the extract of Synergy was the least toxic (88% viability) followed by the extracts of Solitaire 2, Z100 and P60 (75%, 67.5% and 50% viability, respectively). One-way ANOVA revealed highly significant differences between the resin composite materials (plarvae for the extracts of Ketac-Fil, and Vitremer were 32.3%, and 37.0%, respectively. One-way ANOVA revealed highly significant differences between the groups of materials (pshrimp larvae followed by GICs and then composites.

  6. [Dental implant restoration abutment selection].

    Science.gov (United States)

    Bin, Shi; Hao, Zeng

    2017-04-01

    An increasing number of implant restoration abutment types are produced with the rapid development of dental implantology. Although various abutments can meet different clinical demands, the selection of the appropriate abutment is both difficult and confusing. This article aims to help clinicians select the appropriate abutment by describing abutment design, types, and selection criteria.

  7. Wear mechanisms of dental composite restorative materials by two different in-vitro methods

    Directory of Open Access Journals (Sweden)

    Juliana Antonino de Souza

    2013-04-01

    Full Text Available In this work two very simple apparatuses, namely the ball crater (or ball-on-plate and the linear reciprocating (or pin-on-plate tests, were used in order to investigate the wear mechanisms of TPH Spectrum® and Resilab Master® dental composite resins. Loads in the range of 100 g to 1 kg and a total number of up to 24000 cycles were employed. During some of these tests, aqueous aluminum oxide suspensions were used as abrasive agent either diluted or not in distilled water. In case of the ball-on-plate test wear is dominated by abrasive and/or adhesive mechanisms, and is characterized by scratches which are composed of wear defects comprising particle detachment, wear of the polymer matrix and ceramic particle abrasion. However, the relative contributions of the two wear mechanisms could not be determined separately. In case of the pin-on-plate test wear is governed by the fatigue mechanism, although abrasive and adhesive wear mechanism are also present. After a certain number of cycles fatigue wear dominates the wear behavior and results in severe material loss. This mechanism seems to be more important in case of more brittle materials and when higher loads are employed. Qualitative analysis of the results suggests that the combination of these two very simple methods under appropriate conditions can yield sound results which may be representative of a number of clinical situations.

  8. Wear mechanisms of dental composite restorative materials by two different in-vitro methods

    Directory of Open Access Journals (Sweden)

    Juliana Antonino de Souza

    2012-01-01

    Full Text Available In this work two very simple apparatuses, namely the ball crater (or ball-on-plate and the linear reciprocating (or pin-on-plate tests, were used in order to investigate the wear mechanisms of TPH Spectrum® and Resilab Master® dental composite resins. Loads in the range of 100 g to 1 kg and a total number of up to 24000 cycles were employed. During some of these tests, aqueous aluminum oxide suspensions were used as abrasive agent either diluted or not in distilled water. In case of the ball-on-plate test wear is dominated by abrasive and/or adhesive mechanisms, and is characterized by scratches which are composed of wear defects comprising particle detachment, wear of the polymer matrix and ceramic particle abrasion. However, the relative contributions of the two wear mechanisms could not be determined separately. In case of the pin-on-plate test wear is governed by the fatigue mechanism, although abrasive and adhesive wear mechanism are also present. After a certain number of cycles fatigue wear dominates the wear behavior and results in severe material loss. This mechanism seems to be more important in case of more brittle materials and when higher loads are employed. Qualitative analysis of the results suggests that the combination of these two very simple methods under appropriate conditions can yield sound results which may be representative of a number of clinical situations.

  9. Evaluation of the effects of high energy X-ray radiation in materials used in dental restorations

    International Nuclear Information System (INIS)

    Maio, Mireia Florencio; Santos, Adimir dos; Fernandes, Marco Antonio Rodrigues

    2011-01-01

    This work studied the behavior of the physical features and chemical composition of materials used in dental restorations (titanium, amalgam, composite resin and glass ionomer cement) which were submitted to x-ray radiation of 6.0 Mega-Volt (MV) of energy produced in a linear accelerator that is used in radiotherapy of head and neck tumors 1 2. The samples were analyzed using a x-ray fluorescence technique by comparing the chemical composition before and after irradiation. In order to check the residual radiation in the samples, measurements of the sample dosimetry were performed with Geiger-Mueller radiation detectors and an ionization chamber. The samples were also analyzed by gamma-ray spectrometry using a hyper-pure Germanium (HPGe) detector. From these tests, we aimed to verify small changes in the composition of the test bodies due to the radiation. (author)

  10. Evaluation of the effects of high energy X-ray radiation in materials used in dental restorations

    Energy Technology Data Exchange (ETDEWEB)

    Maio, Mireia Florencio; Santos, Adimir dos, E-mail: mfmaio@ipen.br, E-mail: asantos@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Fernandes, Marco Antonio Rodrigues, E-mail: marfernandes@fmb.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Botucatu, SP (Brazil). Departamento de Radioterapia

    2011-07-01

    This work studied the behavior of the physical features and chemical composition of materials used in dental restorations (titanium, amalgam, composite resin and glass ionomer cement) which were submitted to x-ray radiation of 6.0 Mega-Volt (MV) of energy produced in a linear accelerator that is used in radiotherapy of head and neck tumors 1 2. The samples were analyzed using a x-ray fluorescence technique by comparing the chemical composition before and after irradiation. In order to check the residual radiation in the samples, measurements of the sample dosimetry were performed with Geiger-Mueller radiation detectors and an ionization chamber. The samples were also analyzed by gamma-ray spectrometry using a hyper-pure Germanium (HPGe) detector. From these tests, we aimed to verify small changes in the composition of the test bodies due to the radiation. (author)

  11. Adhesive dental materials

    International Nuclear Information System (INIS)

    Unlu, N.

    2005-01-01

    Two main classes of material are involved, the glass-ionomer cements and the composite resins. This investigation describes the way they are bonded to the tooth and highlights their differences. Glass ionomers develop a zone of interaction with the tooth as they age which ultimately gives an extremely strong bond, and results in excellent retention rates. By contrast, bonding of composite resins is more complicated and possibly less effective, though these materials have better wear resistance and better aesthetics than glass ionomers. Assessment of bond durability is difficult. This is because a dental restorative can fail by a number of mechanisms apart from de bonding: for example, through wear or fracture

  12. Dental lesions and restorative treatment in molars

    Directory of Open Access Journals (Sweden)

    Gheorghiu Irina-Maria

    2017-08-01

    Full Text Available This article review specific clinical issues of the molar teeth, as well as the therapeutic approach of their pathology. The dental pathology we face in the group of molars is related to: dental caries, dental trauma (crown and crown-root fractures, dental wear phenomena. The therapeutic approach of the molar teeth is represented by: restoration of the loss of hard dental tissues; endodontic treatments of pulpal and periapical complications; surgical treatment. The restorative treatments in molars are: direct restorations, with or without supplementary anchorage for obturations; inlay, onlay; prosthetic crown.

  13. The use of differential scanning calorimetry for the evaluation of dental materials. I. Cements, cavity lining materials and anterior restorative materials.

    Science.gov (United States)

    McCabe, J F; Wilson, H J

    1980-03-01

    Thermal changes occurring during the setting of restorative materials have been measured accurately using a differential scanning calorimeter. The results were used to evaluate setting characteristics. The heat of reaction and rate of heat output may be significant in determining thermal damage to the pulp. The heat capacity is related to thermal insulation properties. These properties have been determined and their effect on the efficacy of restorative materials discussed.

  14. Occlusal considerations for dental implant restorations.

    Science.gov (United States)

    Bergmann, Ranier H

    2014-01-01

    When placed, dental implants are put into an ever-changing oral environment in which teeth can continue to migrate. Yet, the implants themselves are ankylosed. This can lead to occlusal instability. Teeth may continue to erupt, leaving the implants in infraocclusion. Teeth may move mesially away from an implant, requiring modification to close an open contact point. Friction in the connection between teeth and implants can lead to intrusion of teeth and damage to the periodontal attachment apparatus. Implant occlusion with shallow incisal guidance minimizes lateral and tipping forces. Cross-arch stabilization allows the best distribution of occlusal forces. The choice of restorative materials influences long-term occlusal stability.

  15. Evaluation of the effect of tooth and dental restoration material on electron dose distribution and production of photon contamination in electron beam radiotherapy.

    Science.gov (United States)

    Bahreyni Toossi, Mohammad Taghi; Ghorbani, Mahdi; Akbari, Fatemeh; Mehrpouyan, Mohammad; Sobhkhiz Sabet, Leila

    2016-03-01

    The aim of this study is to evaluate the effect of tooth and dental restoration materials on electron dose distribution and photon contamination production in electron beams of a medical linac. This evaluation was performed on 8, 12 and 14 MeV electron beams of a Siemens Primus linac. MCNPX Monte Carlo code was utilized and a 10 × 10 cm(2) applicator was simulated in the cases of tooth and combinations of tooth and Ceramco C3 ceramic veneer, tooth and Eclipse alloy and tooth and amalgam restoration materials in a soft tissue phantom. The relative electron and photon contamination doses were calculated for these materials. The presence of tooth and dental restoration material changed the electron dose distribution and photon contamination in phantom, depending on the type of the restoration material and electron beam's energy. The maximum relative electron dose was 1.07 in the presence of tooth including amalgam for 14 MeV electron beam. When 100.00 cGy was prescribed for the reference point, the maximum absolute electron dose was 105.10 cGy in the presence of amalgam for 12 MeV electron beam and the maximum absolute photon contamination dose was 376.67 μGy for tooth in 14 MeV electron beam. The change in electron dose distribution should be considered in treatment planning, when teeth are irradiated in electron beam radiotherapy. If treatment planning can be performed in such a way that the teeth are excluded from primary irradiation, the potential errors in dose delivery to the tumour and normal tissues can be avoided.

  16. Evaluation of the effect of tooth and dental restoration material on electron dose distribution and production of photon contamination in electron beam radiotherapy

    International Nuclear Information System (INIS)

    Bahreyni Toossi, M.T.; Ghorbani, Mahdi; Akbari, Fatemah; Sabet, Leila S.; Mehrpouyan, Mohammad

    2016-01-01

    The aim of this study is to evaluate the effect of tooth and dental restoration materials on electron dose distribution and photon contamination production in electron beams of a medical linac. This evaluation was performed on 8, 12 and 14 MeV electron beams of a Siemens Primus linac. MCNPX Monte Carlo code was utilized and a 10 × 10 cm 2 applicator was simulated in the cases of tooth and combinations of tooth and Ceramco C3 ceramic veneer, tooth and Eclipse alloy and tooth and amalgam restoration materials in a soft tissue phantom. The relative electron and photon contamination doses were calculated for these materials. The presence of tooth and dental restoration material changed the electron dose distribution and photon contamination in phantom, depending on the type of the restoration material and electron beam’s energy. The maximum relative electron dose was 1.07 in the presence of tooth including amalgam for 14 MeV electron beam. When 100.00 cGy was prescribed for the reference point, the maximum absolute electron dose was 105.10 cGy in the presence of amalgam for 12 MeV electron beam and the maximum absolute photon contamination dose was 376.67 μGy for tooth in 14 MeV electron beam. The change in electron dose distribution should be considered in treatment planning, when teeth are irradiated in electron beam radiotherapy. If treatment planning can be performed in such a way that the teeth are excluded from primary irradiation, the potential errors in dose delivery to the tumour and normal tissues can be avoided.

  17. Evaluation of effects of ionizing radiation on materials used in dental restorations;Avaliacao dos efeitos da radiacao ionizante em materiais utilizados em restauracoes dentarias

    Energy Technology Data Exchange (ETDEWEB)

    Maio, Mireia Florencio

    2009-07-01

    This work consisted of quantitative studies of the effects caused by ionizing radiation on materials used in dental restorations (Titanium, Amalgam, Resin Composite and Glass Ionomer) aiming the deleterious effects of radiotherapy when patients with tumors in head and neck, arising when the teeth are restored within in the field of radiation. Samples were submitted to X-ray beams of 6 MV from a linear accelerator, VARIAN 2100C model. The samples were analyzed by X-ray fluorescence techniques to compare the chemical composition before and after the irradiation. The sample were submitted to Geiger-Mueller detectors and the ionization chambers in order to verify any residual radiation in the samples. The samples were also analyzed by gamma spectrometry by a Germanium detector. These tests were performed to determine small changes in the composition in the samples due to the radiation interaction. The results of this study may encourage the development of new research for alternative materials in dental restorations that can contribute to improve the quality of life of those patients with tumors of the mouth. (author)

  18. Effects of dental materials on MR images

    International Nuclear Information System (INIS)

    Hinshaw, D.B. Jr.; Hoishouser, B.; Engstrom, H.

    1986-01-01

    As MR imaging of the head and neck area becomes increasingly important in evaluating pathologic conditions of the brain, mid-face, and pharynx, it is becoming apparent that artifacts due to certain dental materials can obscure the findings. Although this fact has been known for some time, a study to identify which materials produce artifacts has not been performed. The authors examined the degree of artifact production caused by various materials commonly used in dental restorations. Since not all dental materials produce artifacts during MR imaging, these materials are described also

  19. Regression of oral lichenoid lesions after replacement of dental restorations.

    Science.gov (United States)

    Mårell, L; Tillberg, A; Widman, L; Bergdahl, J; Berglund, A

    2014-05-01

    The aim of the study was to determine the prognosis and to evaluate the regression of lichenoid contact reactions (LCR) and oral lichen planus (OLP) after replacement of dental restorative materials suspected as causing the lesions. Forty-four referred patients with oral lesions participated in a follow-up study that was initiated an average of 6 years after the first examination at the Department of Odontology, i.e. the baseline examination. The patients underwent odontological clinical examination and answered a questionnaire with questions regarding dental health, medical and psychological health, and treatments undertaken from baseline to follow-up. After exchange of dental materials, regression of oral lesions was significantly higher among patients with LCR than with OLP. As no cases with OLP regressed after an exchange of materials, a proper diagnosis has to be made to avoid unnecessary exchanges of intact restorations on patients with OLP.

  20. Advances in dental materials.

    Science.gov (United States)

    Fleming, Garry J P

    2014-05-01

    The dental market is replete with new resorative materials marketed on the basis of novel technological advances in materials chemistry, bonding capability or reduced operator time and/or technique sensitivity. This paper aims to consider advances in current materials, with an emphasis on their role in supporting contemporary clinical practice.

  1. Mechanical behaviour of dental composite filling materials using digital holography

    OpenAIRE

    Monteiro, J.M.; Lopes, H.; Vaz, M.A.P.; Campos, J.C. Reis

    2010-01-01

    One of the most common clinical problems in dentistry is tooth decay. Among the dental filling materials used to repair tooth structure that has been destroyed by decay are dental amalgam and composite materials based on acrylics. Dental amalgam has been used by dentists for the past 150 years as a dental restorative material due to its low cost, ease of application, strength, durability, and bacteriostatic effects. However its safety as a filling material has been questioned due to th...

  2. Effects of Ceramic Density and Sintering Temperature on the Mechanical Properties of a Novel Polymer-Infiltrated Ceramic-Network Zirconia Dental Restorative (Filling) Material.

    Science.gov (United States)

    Li, Weiyan; Sun, Jian

    2018-05-10

    BACKGROUND Polymer-infiltrated ceramic-network (PICN) dental material is a new and practical development in orthodontics. Sintering is the process of forming a stable solid mass from a powder by heating without melting. The aim of this study was to evaluate the effects of sintering temperature on the mechanical properties of a PICN zirconia dental material. MATERIAL AND METHODS A dense zirconia ceramic and four PICN zirconia dental materials, with varying porosities, were sintered at three different temperatures; 12 PICN zirconia dental materials based on these porous ceramics were prepared, as well as a pure polymer. After the specimen preparation, flexural strength and elastic modulus values were measured using the three-point bending test, and fracture toughness were determined by the single-edge notched beam (SENB) method. The Vickers hardness test method was used with an indentation strength (IS) test. Scanning electron microscopy (SEM) was used to examine the microstructure of the ceramic surface and the fracture surface. RESULTS Mechanical properties of the PICN dental materials, including flexural strength, elastic modulus, fracture toughness, and hardness, were more similar to the properties of natural teeth when compared with traditional dental ceramic materials, and were affected by the density and sintering temperature. SEM showed that the porous ceramic network became cohesive and that the length of cracks in the PICN dental material was reduced. CONCLUSIONS PICN zirconia dental materials were characterized by similar mechanical properties to natural dental tissues, but further studies are required continue to improve the similarities with natural human enamel and dentin.

  3. Clinical Investigation of a New Bulk Fill Composite Resin in the Restoration of Posterior Teeth

    Science.gov (United States)

    2017-09-14

    Dental Restoration Failure of Marginal Integrity; Dental Caries; Unrepairable Overhanging of Dental Restorative Materials; Poor Aesthetics of Existing Restoration; Secondary Dental Caries Associated With Failed or Defective Dental Restorations; Fractured Dental Restorative Materials Without Loss of Materials; Fracture of Dental Restorative Materials With Loss of Material

  4. Dosimetry of accidents using thermoluminescence of dental restorative porcelains

    International Nuclear Information System (INIS)

    Mauricio, C.L.P.; Rosa, L.A.R. da; Cunha, P.G. da

    1986-01-01

    The thermoluminescence (TL) properties of dental restorative porcelain were investigated with the aim of using this material as a TL dosemeter to estimate high doses in radiological accidents. The irradiations were carried out with a 60 Co gamma source and X rays with effective energies from 29 to 95 KeV. The samples have a limit of detection at about 50R and their reproducibility is better than 15%. Linearity was observed from 50 to 5000R. (Author) [pt

  5. Reasons for placement of restorations on previously unrestored tooth surfaces by dentists in The Dental Practice-Based Research Network

    DEFF Research Database (Denmark)

    Nascimento, Marcelle M; Gordan, Valeria V; Qvist, Vibeke

    2010-01-01

    The authors conducted a study to identify and quantify the reasons used by dentists in The Dental Practice-Based Research Network (DPBRN) for placing restorations on unrestored permanent tooth surfaces and the dental materials they used in doing so....

  6. The Historical Evolution of Dental Impression Materials.

    Science.gov (United States)

    Papadiochos, Ioannis; Papadiochou, Sofia; Emmanouil, Ioannis

    The concept of impression making process in dentistry began in the mid 1800s. Dentists realized that the construction of a prosthetic restoration required both a detailed capture of the oral tissues along with stone cast fabrications. To accomplish these goals, impression materials were essential. Beeswax represents the first impression material, while important bechmarks during the historical evolution of dental impression materials are considered to be the introduction of dental trays in the early 1800s and the invention of the gutta-percha, thermoplastic resins and plaster of Paris. The double (corrective) impression technique, along with the functional impression concept that was established after mid 1800s, are also identified as pivotal innovations. During the 20th century, the advances in material development slowed significantly since the majority of the current impression materials had already been invented. However, the introduction of elastomeric impression materials in the field of prosthodontics that offered the advantages of accuracy and dimensional stability substantially upgraded both the impression accuracy and the quality of the final restoration. Presently, the dental practitioner has access to a variety of impression materials and should be aware of their properties, indications and limitations as well. Futhermore, while continuous attempts are being made to enhance these materials, the ideal impression material has yet to be developed. The purpose of this article was to provide a comprehensive review about the historical development of impression dental materials. Copyright American Academy of the History of Dentistry.

  7. Fire victim identification by post-mortem dental CT: Radiologic evaluation of restorative materials after exposure to high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Woisetschlaeger, Mischa, E-mail: Mischa.woisetschlager@lio.se [Center for Medical Image Science and Visualisation (CMIV), University Hospital Linkoeping, Linkoeping University, 58185 Linkoeping (Sweden); Lussi, Adrian, E-mail: anders.persson@cmiv.lio.se [Department of Preventive, Restorative and Pediatric Dentistry, School of Dental Medicine, University of Bern, Freiburgstrasse 7, 3010 Bern (Switzerland); Persson, Anders, E-mail: adrian.lussi@zmk.unibe.ch [Center for Medical Image Science and Visualisation (CMIV), University Hospital Linkoeping, Linkoeping University, 58185 Linkoeping (Sweden); Jackowski, Christian, E-mail: christian.jackowski@irm.uzh.ch [Center for Medical Image Science and Visualisation (CMIV), University Hospital Linkoeping, Linkoeping University, 58185 Linkoeping (Sweden); Institute of Legal Medicine, University of Zuerich, Winterthurerstrasse 190/52, 8057 Zuerich (Switzerland)

    2011-11-15

    Objectives: The aim of this study was to evaluate the use of high resolution CT to radiologically define teeth filling material properties in terms of Hounsfield units after high temperature exposure. Methods: 122 human molars with 10 different filling materials at defined filling diameters were examined. The teeth were CT scanned both before and after the exposure to different temperatures. After image reconstruction, the teeth and filling materials were analyzed regarding their morphology and Hounsfield units (HU) using an extended HU scale. Results: The majority of filling materials diminished in size at temperatures {>=}400 deg. C. HU values were stable for all materials up till 200 deg. C, and only slightly changed up to 600 deg. C. Cerec, Dyract and dentin showed only minor changes in HU at all temperatures. The other materials, inclusive enamel, showed specific patterns, either increasing or decreasing in HU with increasing temperatures over 600 deg. C. Conclusions: Over 600 deg. C the filling materials show specific patterns that can be used to discriminate filling materials. Ultra high resolution CT may improve the identification processes in fire victims. Existing 3D visualization presets for the dentition can be used until 600 deg. C and have to be optimized for bodies exposed to higher temperatures.

  8. Fire victim identification by post-mortem dental CT: Radiologic evaluation of restorative materials after exposure to high temperatures

    International Nuclear Information System (INIS)

    Woisetschlaeger, Mischa; Lussi, Adrian; Persson, Anders; Jackowski, Christian

    2011-01-01

    Objectives: The aim of this study was to evaluate the use of high resolution CT to radiologically define teeth filling material properties in terms of Hounsfield units after high temperature exposure. Methods: 122 human molars with 10 different filling materials at defined filling diameters were examined. The teeth were CT scanned both before and after the exposure to different temperatures. After image reconstruction, the teeth and filling materials were analyzed regarding their morphology and Hounsfield units (HU) using an extended HU scale. Results: The majority of filling materials diminished in size at temperatures ≥400 deg. C. HU values were stable for all materials up till 200 deg. C, and only slightly changed up to 600 deg. C. Cerec, Dyract and dentin showed only minor changes in HU at all temperatures. The other materials, inclusive enamel, showed specific patterns, either increasing or decreasing in HU with increasing temperatures over 600 deg. C. Conclusions: Over 600 deg. C the filling materials show specific patterns that can be used to discriminate filling materials. Ultra high resolution CT may improve the identification processes in fire victims. Existing 3D visualization presets for the dentition can be used until 600 deg. C and have to be optimized for bodies exposed to higher temperatures.

  9. Fluoride-releasing restorative materials and secondary caries.

    Science.gov (United States)

    Hicks, John; Garcia-Godoy, Franklin; Donly, Kevin; Flaitz, Catherine

    2003-03-01

    Secondary caries is responsible for 60 percent of all replacement restorations in the typical dental practice. Risk factors for secondary caries are similar to those for primary caries development. Unfortunately, it is not possible to accurately predict which patients are at risk for restoration failure. During the past several decades, fluoride-releasing dental materials have become a part of the dentist's armamentarium. Considerable fluoride is released during the setting reaction and for periods up to eight years following restoration placement. This released fluoride is readily taken up by the cavosurface tooth structure, as well as the enamel and root surfaces adjacent to the restoration. Resistance against caries along the cavosurface and the adjacent smooth surface has been shown in both in vitro and in vivo studies. Fluoride-releasing dental materials provide for improved resistance against primary and secondary caries in coronal and root surfaces. Plaque and salivary fluoride levels are elevated to a level that facilitates remineralization. In addition, the fluoride released to dental plaque adversely affects the growth of lactobacilli and mutans streptococci by interference with bacterial enzyme systems. Fluoride recharging of these dental materials is readily achieved with fluoridated toothpastes, fluoride mouthrinses, and other sources of topical fluoride. This allows fluoride-releasing dental materials to act as intraoral fluoride reservoirs. The improvement in the properties of dental materials with the ability to release fluoride has improved dramatically in the past decade, and it is anticipated that in the near future the vast majority of restorative procedures will employ fluoride-releasing dental materials as bonding agents, cavity liners, luting agents, adhesives for orthodontic brackets, and definitive restoratives.

  10. Novel Translucent and Strong Submicron Alumina Ceramics for Dental Restorations.

    Science.gov (United States)

    Zhao, M; Sun, Y; Zhang, J; Zhang, Y

    2018-03-01

    An ideal ceramic restorative material should possess excellent aesthetic and mechanical properties. We hypothesize that the high translucency and strength of polycrystalline ceramics can be achieved through microstructural tailoring. The aim of this study is to demonstrate the superior optical and mechanical properties of a new class of submicron grain-sized alumina ceramics relative to the current state-of-the-art dental ceramic materials. The translucency, the in-line transmission ( T IT ) in particular, of these submicron alumina ceramics has been examined with the Rayleigh-Gans-Debye light-scattering model. The theoretical predictions related very well with the measured T IT values. The translucency parameter ( TP) and contrast ratio ( CR) of the newly developed aluminas were measured with a reflectance spectrophotometer on a black-and-white background. For comparison, the T IT , TP, and CR values for a variety of dental ceramics, mostly measured in-house but also cited from the literature, were included. The flexural strength of the aluminas was determined with the 4-point bending test. Our findings have shown that for polycrystalline alumina ceramics, an average grain size ceramic and zirconias, including the most translucent cubic-containing zirconias. The strength of these submicron grain-sized aluminas was significantly higher than that of the cubic-containing zirconia (e.g., Zpex Smile) and lithia-based glass-ceramics (e.g., IPS e.max CAD HT). A coarse-grained alumina could also reach a translucency level comparable to that of dental porcelain. However, the relatively low strength of this material has limited its clinical indications to structurally less demanding applications, such as orthodontic brackets. With a combined high strength and translucency, the newly developed submicron grain-sized alumina may be considered a suitable material for dental restorations.

  11. Complex layered dental restorations: Are they recognizable and do they survive extreme conditions?

    Science.gov (United States)

    Soon, Alistair S; Bush, Mary A; Bush, Peter J

    2015-09-01

    Recent research has shown that restorative dental materials can be recognized by microscopy and elemental analysis (scanning electron microscopy/energy dispersive X-ray spectroscopy and X-ray fluorescence; SEM/EDS and XRF) and that this is possible even in extreme conditions, such as cremation. These analytical methods and databases of dental materials properties have proven useful in DVI (disaster victim identification) of a commercial plane crash in 2009, and in a number of other victim identification cases. Dental materials appear on the market with ever expanding frequency. With their advent, newer methods of restoration have been proposed and adopted in the dental office. Methods might include placing multiple layers of dental materials, where they have different properties including adhesion, viscosity, or working time. These different dental materials include filled adhesives, flowable resins, glass ionomer cements, composite resins, liners and sealants. With possible combinations of different materials in these restorations, the forensic odontologist is now confronted with a new difficulty; how to recognize each individual material. The question might be posed if it is even possible to perform this task. Furthermore, an odontologist might be called upon to identify a victim under difficult circumstances, such as when presented with fragmented or incinerated remains. In these circumstances the ability to identify specific dental materials could assist in the identification of the deceased. Key to use of this information is whether these new materials and methods are detailed in the dental chart. Visual or radiographic inspection may not reveal the presence of a restoration, let alone the possible complex nature of that restoration. This study demonstrates another scientific method in forensic dental identification. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  12. Restorative Rehabilitation of a Patient with Dental Erosion

    OpenAIRE

    AlShahrani, Mohammed Thamer; Haralur, Satheesh B.; Alqarni, Mohammed

    2017-01-01

    Dental erosion is the chemical dissolution of the tooth structure. Factors like eating disorders and gastrointestinal diseases are recognized as intrinsic factors for dental erosion. Advanced stages of dental erosion extensively damage the tooth morphology, consequently affecting both esthetics and functions. Reports indicate the growing prevalence of erosion, and hence knowledge of restorative rehabilitation of tooth erosion is an integral part of the contemporary dental practice. This clini...

  13. Understanding dental CAD/CAM for restorations - dental milling machines from a mechanical engineering viewpoint. Part A: chairside milling machines.

    Science.gov (United States)

    Lebon, Nicolas; Tapie, Laurent; Duret, Francois; Attal, Jean-Pierre

    2016-01-01

    The dental milling machine is an important device in the dental CAD/CAM chain. Nowadays, dental numerical controlled (NC) milling machines are available for dental surgeries (chairside solution). This article provides a mechanical engineering approach to NC milling machines to help dentists understand the involvement of technology in digital dentistry practice. First, some technical concepts and definitions associated with NC milling machines are described from a mechanical engineering viewpoint. The technical and economic criteria of four chairside dental NC milling machines that are available on the market are then described. The technical criteria are focused on the capacities of the embedded technologies of these milling machines to mill both prosthetic materials and types of shape restorations. The economic criteria are focused on investment costs and interoperability with third-party software. The clinical relevance of the technology is assessed in terms of the accuracy and integrity of the restoration.

  14. Restorative Rehabilitation of a Patient with Dental Erosion.

    Science.gov (United States)

    AlShahrani, Mohammed Thamer; Haralur, Satheesh B; Alqarni, Mohammed

    2017-01-01

    Dental erosion is the chemical dissolution of the tooth structure. Factors like eating disorders and gastrointestinal diseases are recognized as intrinsic factors for dental erosion. Advanced stages of dental erosion extensively damage the tooth morphology, consequently affecting both esthetics and functions. Reports indicate the growing prevalence of erosion, and hence knowledge of restorative rehabilitation of tooth erosion is an integral part of the contemporary dental practice. This clinical report describes an adult patient with gastroesophageal reflux induced dental erosion involving the palatal surface of the maxillary anterior teeth. The extensive involvement of the palatal surfaces compromised the esthetics, incisal guidance, and functional occlusal efficiency. Indirect all-ceramic restorations were utilized to restore the esthetics and occlusal reconstruction. In conclusion, patients affected by severe dental erosion require prosthetic rehabilitation besides the management of the associated medical condition.

  15. Restorative Rehabilitation of a Patient with Dental Erosion

    Directory of Open Access Journals (Sweden)

    Mohammed Thamer AlShahrani

    2017-01-01

    Full Text Available Dental erosion is the chemical dissolution of the tooth structure. Factors like eating disorders and gastrointestinal diseases are recognized as intrinsic factors for dental erosion. Advanced stages of dental erosion extensively damage the tooth morphology, consequently affecting both esthetics and functions. Reports indicate the growing prevalence of erosion, and hence knowledge of restorative rehabilitation of tooth erosion is an integral part of the contemporary dental practice. This clinical report describes an adult patient with gastroesophageal reflux induced dental erosion involving the palatal surface of the maxillary anterior teeth. The extensive involvement of the palatal surfaces compromised the esthetics, incisal guidance, and functional occlusal efficiency. Indirect all-ceramic restorations were utilized to restore the esthetics and occlusal reconstruction. In conclusion, patients affected by severe dental erosion require prosthetic rehabilitation besides the management of the associated medical condition.

  16. The presence of antimony in various dental filling materials

    International Nuclear Information System (INIS)

    Molokhia, Anat; Combe, E.C.; Lilley, J.D.

    1985-01-01

    Antimony was determined in a number of non-metallic dental materials currently used for tooth restoration. The method applied was instrumental neutron activation analysis. The concentration of antimony in some of the brands tested was found to be as high as 900 fold that in the normal hard dental tissues. (author)

  17. Effect of a Simulation Exercise on Restorative Identification Skills of First Year Dental Hygiene Students.

    Science.gov (United States)

    Lemaster, Margaret; Flores, Joyce M; Blacketer, Margaret S

    2016-02-01

    This study explored the effectiveness of simulated mouth models to improve identification and recording of dental restorations when compared to using traditional didactic instruction combined with 2-dimensional images. Simulation has been adopted into medical and dental education curriculum to improve both student learning and patient safety outcomes. A 2-sample, independent t-test analysis of data was conducted to compare graded dental recordings of dental hygiene students using simulated mouth models and dental hygiene students using 2-dimensional photographs. Evaluations from graded dental charts were analyzed and compared between groups of students using the simulated mouth models containing random placement of custom preventive and restorative materials and traditional 2-dimensional representations of didactically described conditions. Results demonstrated a statistically significant (p≤0.0001) difference: for experimental group, students using the simulated mouth models to identify and record dental conditions had a mean of 86.73 and variance of 33.84. The control group students using traditional 2-dimensional images mean graded dental chart scores were 74.43 and variance was 14.25. Using modified simulation technology for dental charting identification may increase level of dental charting skill competency in first year dental hygiene students. Copyright © 2016 The American Dental Hygienists’ Association.

  18. Atraumatic restorative treatment versus conventional restorative treatment for managing dental caries.

    Science.gov (United States)

    Dorri, Mojtaba; Martinez-Zapata, Maria José; Walsh, Tanya; Marinho, Valeria Cc; Sheiham Deceased, Aubrey; Zaror, Carlos

    2017-12-28

    Dental caries is a sugar-dependent disease that damages tooth structure and, due to loss of mineral components, may eventually lead to cavitation. Dental caries is the most prevalent disease worldwide and is considered the most important burden of oral health. Conventional treatment methods (drill and fill) involve the use of rotary burs under local anaesthesia. The need for an electricity supply, expensive handpieces and highly trained dental health personnel may limit access to dental treatment, especially in underdeveloped regions.To overcome the limitations of conventional restorative treatment, the Atraumatic Restorative Treatment (ART) was developed, mainly for treating caries in children living in under-served areas of the world where resources and facilities such as electricity and trained manpower are limited. ART is a minimally invasive approach which involves removal of decayed tissue using hand instruments alone, usually without use of anaesthesia and electrically driven equipment, and restoration of the dental cavity with an adhesive material (glass ionomer cement (GIC), composite resins, resin-modified glass-ionomer cement (RM-GICs) and compomers). To assess the effects of Atraumatic Restorative Treatment (ART) compared with conventional treatment for managing dental caries lesions in the primary and permanent teeth of children and adults. Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 22 February 2017), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2017, Issue 1), MEDLINE Ovid (1946 to 22 February 2017), Embase Ovid (1980 to 22 February 2017), LILACS BIREME Virtual Health Library (Latin American and Caribbean Health Science Information database; 1982 to 22 February 2017) and BBO BIREME Virtual Health Library (Bibliografia Brasileira de Odontologia; 1986 to 22 February 2017). The US National Institutes of Health Trials Registry (Clinical

  19. Retention of class V restorations placed by dental students: a retrospective evaluation

    OpenAIRE

    Silva, Úrsula Aparecida Escalero; Department of Restorative Dentistry – Araçatuba Dental School – UNESP – Univ Estadual Paulista – Araçatuba – São Paulo – Brazil.; da Silva, Emílie; Department of Restorative Dentistry – Araçatuba Dental School – UNESP – Univ Estadual Paulista – Araçatuba – São Paulo – Brazil.; Okida, Ricardo; Department of Restorative Dentistry – Araçatuba Dental School – UNESP – Univ Estadual Paulista – Araçatuba – São Paulo – Brazil.; Sundefeld, Maria; Department of Biostatistics – Araçatuba Dental School – UNESP – Univ Estadual Paulista – Araçatuba – São Paulo – Brazil.; Fagundes, Ticiane Cestari; Department of Restorative Dentistry – Araçatuba Dental School – UNESP – Univ Estadual Paulista – Araçatuba – São Paulo – Brazil.

    2016-01-01

    Objective: The aim of this study was to evaluate the clinical performance of class V restorations made by undergraduate students and determine the factors that might influence retention of restorations. Material and Methods: A survey of the clinical records created between 2007 and 2009 was used to collect data on patients with dental restorations. The USPHS (United States Public Health Service) criteria were used to perform evaluations by direct clinical observation. Statistical analyses wer...

  20. Components of patient satisfaction with a dental restorative visit

    DEFF Research Database (Denmark)

    Riley, Joseph L; Gordan, Valeria V; Rindal, D Brad

    2012-01-01

    The authors conducted a study to identify components of patient satisfaction with restorative dental care and to test the hypothesis that certain dentist, patient and procedure factors are associated with patient satisfaction.......The authors conducted a study to identify components of patient satisfaction with restorative dental care and to test the hypothesis that certain dentist, patient and procedure factors are associated with patient satisfaction....

  1. Syllabus of Dental Materials

    Science.gov (United States)

    1984-07-01

    Rubberloid Van R Dental Prod. Surgident Lactona Corp. Alginates Coe Alginate Coe Labs o Jeltrate L.D. Caulk Kerr Alginate Kerr/Sybron Alginate S.S. White Co...Surgident- Alginate Lactona Corp. Unijel II Unitek Corp. O Combination Agar/a ig inate Colloid 80 U.S. Shiza Corp. Dentloid Denterials, Ltd...66061 (215) 277-3800 (913) 782-2200 Shofu Dental Corp. Lactona Corp. (subsidary of 4025 Bohannon Dr. Warner-Lambert Co.) Menlo Park, CA 94025 . Academy

  2. Color stability evaluation of aesthetic restorative materials

    Directory of Open Access Journals (Sweden)

    Adriana Postiglione Bührer Samra

    2008-09-01

    Full Text Available Color match is one of the most important characteristics of aesthetic restorative materials. Maintenance of color throughout the functional lifetime of restorations is important for the durability of treatment. This characteristic is not constant among dental materials. The purpose of this research was to assess the color stability of five aesthetic restorative materials when immersed in a coffee solution. Seventy-one 17 mm x 1 mm specimens, divided into five groups, were made using one direct composite resin (Tetric Ceram®, Ivoclar/Vivadent - G1, three indirect composite resins (Targis, Ivoclar/Vivadent - G2; Resilab Master, Wilcos - G3; belleGlassTM HP, Kerr - G4 and one porcelain (IPS Empress® 2, Ivoclar/Vivadent - G5. The specimens were immersed in a coffee staining media for 15 days and stored under a controlled temperature of 37°C ± 1°C in the dark. The evaluations were made after 1, 7 and 15 days by means of reflectance spectrophotometry. The data was submitted to two-way ANOVA (p < 0.005 and post hoc tests. Statistical difference was observed between G1 / G3 and the other groups; G2 / G4 and the other groups; and G5 and all the other groups. It was concluded that G1 and G3 showed significantly higher discoloration than the other groups. G2 and G4 showed intermediary pigmentation, while G5 showed the smallest changes.

  3. Restorative Management of Intrinsic and Extrinsic Dental Erosion.

    Science.gov (United States)

    Al-Salehi, Samira Kathryn

    2014-12-01

    The restorative management of tooth surface loss is highlighted through the presentation of two advanced cases of dental erosion. On presentation, the causes of the dental erosion in both patients had been previously diagnosed and stopped. The first patient was a 67 year old with intrinsic erosion and an element of attrition where a multidisciplinary approach was used. The other, a 17 year old patient with extrinsic erosion managed via adhesive restorations. Adhesive techniques are a relatively simple, effective and conservative method for the treatment of dental erosion. The two treatment modalities (conventional versus contemporary) are compared and discussed.

  4. The demand for preventive and restorative dental services.

    Science.gov (United States)

    Meyerhoefer, Chad D; Zuvekas, Samuel H; Manski, Richard

    2014-01-01

    Chronic tooth decay is the most common chronic condition in the United States among children ages 5-17 and also affects a large percentage of adults. Oral health conditions are preventable, but less than half of the US population uses dental services annually. We seek to examine the extent to which limited dental coverage and high out-of-pocket costs reduce dental service use by the nonelderly privately insured and uninsured. Using data from the 2001-2006 Medical Expenditure Panel Survey and an American Dental Association survey of dental procedure prices, we jointly estimate the probability of using preventive and both basic and major restorative services through a correlated random effects specification that controls for endogeneity. We found that dental coverage increased the probability of preventive care use by 19% and the use of restorative services 11% to 16%. Both conditional and unconditional on dental coverage, the use of dental services was not sensitive to out-of-pocket costs. We conclude that dental coverage is an important determinant of preventive dental service use, but other nonprice factors related to consumer preferences, especially education, are equal if not stronger determinants. Copyright © 2013 John Wiley & Sons, Ltd.

  5. To Analyse the Erosive Potential of Commercially Available Drinks on Dental Enamel and Various Tooth Coloured Restorative Materials - An In-vitro Study.

    Science.gov (United States)

    Karda, Babita; Jindal, Ritu; Mahajan, Sandeep; Sandhu, Sanam; Sharma, Sunila; Kaur, Rajwinder

    2016-05-01

    With the enormous change in life style pattern of a common man through the past few decades, there has been proportional variation in the amount and frequency of consumption of drinks. An increased consumption of these drinks will concurrently increase enamel surface roughness by demineralization, resulting in hypersensitivity and elevated caries risk. The present study was designed to evaluate the erosive potential of commercially available drinks on tooth enamel and various tooth coloured restorative materials. Extracted human teeth were taken and divided into four groups i.e. tooth enamel, glass ionomer cement, composite and compomer. Four commercially available drinks were chosen these were Coca -Cola, Nimbooz, Frooti and Yakult. The pH of each drink was measured. Each group was immersed in various experimental drinks for a period of 14 days. The erosive potential of each drink was measured by calculating the change in average surface roughness of these groups after the immersion protocol in various drinks. The data analysis was done by One Way Anova, Post-Hoc Bonferroni, and paired t -test. Group II-GIC showed highest values for mean of change in average surface roughness and the values were statistically significant (pCoca-cola showed the highest erosive potential and Yakult showed the lowest, there was no statistical significant difference between the results shown by Yakult and Frooti. Characteristics which may promote erosion of enamel and tooth coloured restorative materials were surface texture of the material and pH of the drinks.

  6. Management of periodontal destruction caused by overhanging dental restoration

    Directory of Open Access Journals (Sweden)

    Misnova Misnova

    2016-06-01

    Full Text Available Periodontal tissue inflammations are occasionally caused by positions of restoration margins, particularly if they are placed subgingivally. A 44-year old male was referred to the Dental and Mouth Hospital of Dentistry Faculty Hasanuddin University with the chief complaint of severe pain at right posterior maxillary. Clinical examinations demonstrate a 7-mm periodontal pocket at buccal aspect of 16 teeth with tooth mobility °2. Overhanging dental composite restorations of Class V were detected at the subgingival areas of 15, 16, and 17. Radiographic results show vertically and horizontally alveolar bone loss. This case report is aimed to describe the management of periodontal tissue destruction as a result of overhanging dental composite restorations. Scaling and root planing were conducted as the initial therapy. The periodontal surgery was performed a week after the initial therapy. A full-thickness flap design with sulcular incision from 14 to 18 was made before the pocket curretage and necrotic tissue debridement along with restoration recontouring. The flap was sutured with simple suture technique. Periodontal dressing was packed for a week. Antibiotics, analgetics and antiinflammatory drugs were prescribed per orally. There was no history of pain a week after the surgical procedure. Tooth mobility was decreased to °1 and the periodontal pocket was reduced to 3 mm. Overhanging dental restorations may lead to periodontal tissue destruction. The subgingivally placement of those restorations should consider the health of periodontal tissues.

  7. Equivalent Young's modulus of composite resin for simulation of stress during dental restoration.

    Science.gov (United States)

    Park, Jung-Hoon; Choi, Nak-Sam

    2017-02-01

    For shrinkage stress simulation in dental restoration, the elastic properties of composite resins should be acquired beforehand. This study proposes a formula to measure the equivalent Young's modulus of a composite resin through a calculation scheme of the shrinkage stress in dental restoration. Two types of composite resins remarkably different in the polymerization shrinkage strain were used for experimental verification: the methacrylate-type (Clearfil AP-X) and the silorane-type (Filtek P90). The linear shrinkage strains of the composite resins were gained through the bonded disk method. A formula to calculate the equivalent Young's moduli of composite resin was derived on the basis of the restored ring substrate. Equivalent Young's moduli were measured for the two types of composite resins through the formula. Those values were applied as input to a finite element analysis (FEA) for validation of the calculated shrinkage stress. Both of the measured moduli through the formula were appropriate for stress simulation of dental restoration in that the shrinkage stresses calculated by the FEA were in good agreement within 3.5% with the experimental values. The concept of equivalent Young's modulus so measured could be applied for stress simulation of 2D and 3D dental restoration. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  8. Fractographic features of glass-ceramic and zirconia-based dental restorations fractured during clinical function.

    Science.gov (United States)

    Oilo, Marit; Hardang, Anne D; Ulsund, Amanda H; Gjerdet, Nils R

    2014-06-01

    Fractures during clinical function have been reported as the major concern associated with all-ceramic dental restorations. The aim of this study was to analyze the fracture features of glass-ceramic and zirconia-based restorations fractured during clinical use. Twenty-seven crowns and onlays were supplied by dentists and dental technicians with information about type of cement and time in function, if available. Fourteen lithium disilicate glass-ceramic restorations and 13 zirconia-based restorations were retrieved and analyzed. Fractographic features were examined using optical microscopy to determine crack initiation and crack propagation of the restorations. The material comprised fractured restorations from one canine, 10 incisors, four premolars, and 11 molars. One crown was not categorized because of difficulty in orientation of the fragments. The results revealed that all core and veneer fractures initiated in the cervical margin and usually from the approximal area close to the most coronally placed curvature of the margin. Three cases of occlusal chipping were found. The margin of dental all-ceramic single-tooth restorations was the area of fracture origin. The fracture features were similar for zirconia, glass-ceramic, and alumina single-tooth restorations. Design features seem to be of great importance for fracture initiation. © 2014 Eur J Oral Sci.

  9. Factors influencing the dimensional accuracy of 3D-printed full-coverage dental restorations using stereolithography technology

    NARCIS (Netherlands)

    Alharbi, N.; Osman, R.B.; Wismeijer, D.

    2016-01-01

    Purpose: The aim of the present study was to evaluate the effect of the build angle and the support configuration (thick versus thin support) on the dimensional accuracy of 3D-printed full-coverage dental restorations. Materials and Methods: A full-coverage dental crown was digitally designed and

  10. Relevant optical properties for direct restorative materials.

    Science.gov (United States)

    Pecho, Oscar E; Ghinea, Razvan; do Amaral, Erika A Navarro; Cardona, Juan C; Della Bona, Alvaro; Pérez, María M

    2016-05-01

    To evaluate relevant optical properties of esthetic direct restorative materials focusing on whitened and translucent shades. Enamel (E), body (B), dentin (D), translucent (T) and whitened (Wh) shades for E (WhE) and B (WhB) from a restorative system (Filtek Supreme XTE, 3M ESPE) were evaluated. Samples (1 mm thick) were prepared. Spectral reflectance (R%) and color coordinates (L*, a*, b*, C* and h°) were measured against black and white backgrounds, using a spectroradiometer, in a viewing booth, with CIE D65 illuminant and d/0° geometry. Scattering (S) and absorption (K) coefficients and transmittance (T%) were calculated using Kubelka-Munk's equations. Translucency (TP) and opalescence (OP) parameters and whiteness index (W*) were obtained from differences of CIELAB color coordinates. R%, S, K and T% curves from all shades were compared using VAF (Variance Accounting For) coefficient with Cauchy-Schwarz inequality. Color coordinates and optical parameters were statistically analyzed using one-way ANOVA, Tukey's test with Bonferroni correction (α=0.0007). Spectral behavior of R% and S were different for T shades. In addition, T shades showed the lowest R%, S and K values, as well as the highest T%, TP an OP values. In most cases, WhB shades showed different color and optical properties (including TP and W*) than their corresponding B shades. WhE shades showed similar mean W* values and higher mean T% and TP values than E shades. When using whitened or translucent composites, the final color is influenced not only by the intraoral background but also by the color and optical properties of multilayers used in the esthetic restoration. Copyright © 2016 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  11. Synchrotron-radiation-based X-ray micro-computed tomography reveals dental bur debris under dental composite restorations.

    Science.gov (United States)

    Hedayat, Assem; Nagy, Nicole; Packota, Garnet; Monteith, Judy; Allen, Darcy; Wysokinski, Tomasz; Zhu, Ning

    2016-05-01

    Dental burs are used extensively in dentistry to mechanically prepare tooth structures for restorations (fillings), yet little has been reported on the bur debris left behind in the teeth, and whether it poses potential health risks to patients. Here it is aimed to image dental bur debris under dental fillings, and allude to the potential health hazards that can be caused by this debris when left in direct contact with the biological surroundings, specifically when the debris is made of a non-biocompatible material. Non-destructive micro-computed tomography using the BioMedical Imaging & Therapy facility 05ID-2 beamline at the Canadian Light Source was pursued at 50 keV and at a pixel size of 4 µm to image dental bur fragments under a composite resin dental filling. The bur's cutting edges that produced the fragment were also chemically analyzed. The technique revealed dental bur fragments of different sizes in different locations on the floor of the prepared surface of the teeth and under the filling, which places them in direct contact with the dentinal tubules and the dentinal fluid circulating within them. Dispersive X-ray spectroscopy elemental analysis of the dental bur edges revealed that the fragments are made of tungsten carbide-cobalt, which is bio-incompatible.

  12. Practitioner, patient and carious lesion characteristics associated with type of restorative material

    DEFF Research Database (Denmark)

    Makhija, Sonia K; Gordan, Valeria V; Gilbert, Gregg H

    2011-01-01

    The authors conducted a study to identify factors associated with the materials that dentists in The Dental Practice-Based Research Network (DPBRN) use when placing the first restoration on permanent posterior tooth surfaces....

  13. Nanoscale Mobility of Aqueous Polyacrylic Acid in Dental Restorative Cements.

    Science.gov (United States)

    Berg, Marcella C; Benetti, Ana R; Telling, Mark T F; Seydel, Tilo; Yu, Dehong; Daemen, Luke L; Bordallo, Heloisa N

    2018-03-28

    Hydrogen dynamics in a time range from hundreds of femtoseconds to nanoseconds can be directly analyzed using neutron spectroscopy, where information on the inelastic and quasi-elastic scattering, hereafter INS and QENS, can be obtained. In this study, we applied these techniques to understand how the nanoscale mobility of the aqueous solution of polyacrylic acid (PAA) used in conventional glass ionomer cements (GICs) changes under confinement. Combining the spectroscopic analysis with calorimetric results, we were able to separate distinct motions within both the liquid and the GICs. The QENS analysis revealed that the self-diffusion translational motion identified in the liquid is also visible in the GIC. However, as a result of the formation of the cement matrix and its setting, both translational diffusion and residence time differed from the PAA solution. When comparing the local diffusion obtained for the selected GIC, the only noticeable difference was observed for the slow dynamics associated with the polymer chain. Additionally, over short-term aging, progressive water binding to the polymer chain occurred in one of the investigated GICs. Finally, a considerable change in the density of the GIC without progressive water binding indicates an increased polymer cross-linking. Taken together, our results suggest that accurate and deep understanding of polymer-water binding, polymer cross-linking, as well as material density changes occurring during the maturation process of GIC are necessary for the development of advanced dental restorative materials.

  14. Dental ceramics: a review of new materials and processing methods.

    Science.gov (United States)

    Silva, Lucas Hian da; Lima, Erick de; Miranda, Ranulfo Benedito de Paula; Favero, Stéphanie Soares; Lohbauer, Ulrich; Cesar, Paulo Francisco

    2017-08-28

    The evolution of computerized systems for the production of dental restorations associated to the development of novel microstructures for ceramic materials has caused an important change in the clinical workflow for dentists and technicians, as well as in the treatment options offered to patients. New microstructures have also been developed by the industry in order to offer ceramic and composite materials with optimized properties, i.e., good mechanical properties, appropriate wear behavior and acceptable aesthetic characteristics. The objective of this literature review is to discuss the main advantages and disadvantages of the new ceramic systems and processing methods. The manuscript is divided in five parts: I) monolithic zirconia restorations; II) multilayered dental prostheses; III) new glass-ceramics; IV) polymer infiltrated ceramics; and V) novel processing technologies. Dental ceramics and processing technologies have evolved significantly in the past ten years, with most of the evolution being related to new microstructures and CAD-CAM methods. In addition, a trend towards the use of monolithic restorations has changed the way clinicians produce all-ceramic dental prostheses, since the more aesthetic multilayered restorations unfortunately are more prone to chipping or delamination. Composite materials processed via CAD-CAM have become an interesting option, as they have intermediate properties between ceramics and polymers and are more easily milled and polished.

  15. Dental ceramics: a review of new materials and processing methods

    Directory of Open Access Journals (Sweden)

    Lucas Hian da SILVA

    2017-08-01

    Full Text Available Abstract The evolution of computerized systems for the production of dental restorations associated to the development of novel microstructures for ceramic materials has caused an important change in the clinical workflow for dentists and technicians, as well as in the treatment options offered to patients. New microstructures have also been developed by the industry in order to offer ceramic and composite materials with optimized properties, i.e., good mechanical properties, appropriate wear behavior and acceptable aesthetic characteristics. The objective of this literature review is to discuss the main advantages and disadvantages of the new ceramic systems and processing methods. The manuscript is divided in five parts: I monolithic zirconia restorations; II multilayered dental prostheses; III new glass-ceramics; IV polymer infiltrated ceramics; and V novel processing technologies. Dental ceramics and processing technologies have evolved significantly in the past ten years, with most of the evolution being related to new microstructures and CAD-CAM methods. In addition, a trend towards the use of monolithic restorations has changed the way clinicians produce all-ceramic dental prostheses, since the more aesthetic multilayered restorations unfortunately are more prone to chipping or delamination. Composite materials processed via CAD-CAM have become an interesting option, as they have intermediate properties between ceramics and polymers and are more easily milled and polished.

  16. Liquid crystalline epoxy nanocomposite material for dental application

    Directory of Open Access Journals (Sweden)

    Yun-Yuan Tai

    2015-01-01

    Conclusion: The microhardness of the bracket-like blocks made by our new material is superior to the commercially available brackets, even after thermocycling. Our results indicate that the evaluated liquid crystalline epoxy nanocomposite materials are of an appropriate quality for application in dental core and post systems and in various restorations. By applying technology to refine manufacturing processes, these new materials could also be used to fabricate esthetic brackets for orthodontic treatment.

  17. Modelling the Longevity of Dental Restorations by means of a CBR System

    Directory of Open Access Journals (Sweden)

    Ignacio J. Aliaga

    2015-01-01

    Full Text Available The lifespan of dental restorations is limited. Longevity depends on the material used and the different characteristics of the dental piece. However, it is not always the case that the best and longest lasting material is used since patients may prefer different treatments according to how noticeable the material is. Over the last 100 years, the most commonly used material has been silver amalgam, which, while very durable, is somewhat aesthetically displeasing. Our study is based on the collection of data from the charts, notes, and radiographic information of restorative treatments performed by Dr. Vera in 1993, the analysis of the information by computer artificial intelligence to determine the most appropriate restoration, and the monitoring of the evolution of the dental restoration. The data will be treated confidentially according to the Organic Law 15/1999 on 13 December on the Protection of Personal Data. This paper also presents a clustering technique capable of identifying the most significant cases with which to instantiate the case-base. In order to classify the cases, a mixture of experts is used which incorporates a Bayesian network and a multilayer perceptron; the combination of both classifiers is performed with a neural network.

  18. Improved single- and multi-contact life-time testing of dental restorative materials using key characteristics of the human masticatory system and a force/position-controlled robotic dental wear simulator.

    Science.gov (United States)

    Raabe, D; Harrison, A; Ireland, A; Alemzadeh, K; Sandy, J; Dogramadzi, S; Melhuish, C; Burgess, S

    2012-03-01

    . Experimental studies of wear using this simulator demonstrate that integrating the biological feature of combined force/position hybrid control in dental material testing improves the linearity and reduces the variability of results. In addition, it has been shown that present biaxially operated dental wear simulators are likely to provide misleading results in comparative in vitro/in vivo one-contact studies due to neglecting the occlusal sliding motion in one plane which could introduce an error of up to 49% since occlusal sliding motion D and volumetric wear loss V(loss) are proportional.

  19. Improved single- and multi-contact life-time testing of dental restorative materials using key characteristics of the human masticatory system and a force/position-controlled robotic dental wear simulator

    International Nuclear Information System (INIS)

    Raabe, D; Dogramadzi, S; Melhuish, C; Harrison, A; Alemzadeh, K; Burgess, S; Ireland, A; Sandy, J

    2012-01-01

    . Experimental studies of wear using this simulator demonstrate that integrating the biological feature of combined force/position hybrid control in dental material testing improves the linearity and reduces the variability of results. In addition, it has been shown that present biaxially operated dental wear simulators are likely to provide misleading results in comparative in vitro/in vivo one-contact studies due to neglecting the occlusal sliding motion in one plane which could introduce an error of up to 49% since occlusal sliding motion D and volumetric wear loss V loss are proportional.

  20. Understanding dental CAD/CAM for restorations--dental milling machines from a mechanical engineering viewpoint. Part B: labside milling machines.

    Science.gov (United States)

    Lebon, Nicolas; Tapie, Laurent; Duret, Francois; Attal, Jean-Pierre

    2016-01-01

    Nowadays, dental numerical controlled (NC) milling machines are available for dental laboratories (labside solution) and dental production centers. This article provides a mechanical engineering approach to NC milling machines to help dental technicians understand the involvement of technology in digital dentistry practice. The technical and economic criteria are described for four labside and two production center dental NC milling machines available on the market. The technical criteria are focused on the capacities of the embedded technologies of milling machines to mill prosthetic materials and various restoration shapes. The economic criteria are focused on investment cost and interoperability with third-party software. The clinical relevance of the technology is discussed through the accuracy and integrity of the restoration. It can be asserted that dental production center milling machines offer a wider range of materials and types of restoration shapes than labside solutions, while labside solutions offer a wider range than chairside solutions. The accuracy and integrity of restorations may be improved as a function of the embedded technologies provided. However, the more complex the technical solutions available, the more skilled the user must be. Investment cost and interoperability with third-party software increase according to the quality of the embedded technologies implemented. Each private dental practice may decide which fabrication option to use depending on the scope of the practice.

  1. [Influence of the fluoride releasing dental materials on the bacterial flora of dental plaque].

    Science.gov (United States)

    Płuciennik, Małgorzata; Sakowska, Danuta; Krzemiński, Zbigniew; Piatowska, Danuta

    2008-01-01

    The assessment of influence of silver-free, fluor releasing dental materials on dental plaque bacteria quantity. 17 patients were included into the study. 51 restorations were placed following manufacturers recommendations. Following materials were used: conventional glassionomer Ketac-Molar ESPE, resin modified glassionomer Fuji II LC GC and fluor containing composite Charisma Heraeus Kulzer Class V restorations were placed in following teeth of upper and lower jaw: canines, first bicuspids, second bicuspids. Sound enamel was a control. After 10 weeks the 72 hours old dental plaque was collected from surface of restorations and control using sterile probe. Total amount of 68 dental plaques were investigated. Each plaque was placed on scaled and sterile aluminum foil. The moist weight of dental plaque was scaled. Dental plaque was moved into 7 ml 0.85% NaCl solution reduced by cystein chlorine hydrogen and disintegrated by ultrasounds (power:100 Watt, wave amplitude: 5 micorm). The suspension of dental plaque was serially diluted from 10(-4) to 10(-5) in sterile 0,85% NaCl solution, and seeded with amount of 0.1 ml on appropriate base. In dental plaque trials the amount of cariogenic bacteria was calculated--Streptococcus mutans, Streptococcus, Lactobacillus, Veillonella and Neisseria, and also total amount of aerobic and anaerobic bacteria was measured. Microbiologic studies were performed in Institute of Microbiology, Medical University, Łódź. Statistical analysis of collected data was accomplished. In 72 hours old dental plaques collected from the surfaces of Ketac -Molar, Fuji II LC, Charisma after 10 weeks since being placed into the class V cavity, results show no statistically significant differences in the amount of Streptococcus mutans, Streptococcus spp., Lactobacillus spp., Veillonella spp., Neisseria spp, in total amount of aerobic and anaerobic bacteria and in the quantity proportion of Streptococcus mutans versus Streptococcus spp. in comparison

  2. Effect of prophylactic treatments on the superficial roughness of dental tissues and of two esthetic restorative materials Efeito de tratamentos profiláticos na rugosidade superficial de tecidos dentais e de dois materiais restauradores estéticos

    Directory of Open Access Journals (Sweden)

    Daniele Salami

    2003-03-01

    Full Text Available Dental prophylaxis is a common way to remove dental plaque and stain, both undesirable factors in most dentistry procedures. However, besides cleaning the tooth surface, prophylactic techniques may increase the surface roughness of restorations and dental tissues, which, in turn, may result in plaque accumulation, superficial staining and superficial degradation. This study evaluated the effect of three prophylactic techniques - sodium bicarbonate jet, pumice paste and whiting paste - on the superficial roughness of two restorative materials - a composite resin and a compomer - and on the superficial roughness of two dental surfaces - enamel and cementum/dentin - through rugosimetric and scanning electron microscopy (SEM analysis. Statistical analysis of the rugosimetric data showed that the use of pumice paste on enamel produced a significantly smoother surface than the natural surface. However, comparing the effect of the three techniques, prophylaxis with the pumice paste produced a rougher surface than did the other techniques as regards enamel and cementum/dentin probably due to its abrasiveness. On composite resin, the pumice paste only produced a rougher surface than did the whiting paste. On compomer, all of the applied treatments produced similar results. Based on rugosimetric and SEM analysis, we could conclude that the prophylactic treatments employed did not improve roughness of the studied surfaces. As to the effects of the techniques, they were different depending on the surfaces on which the prophylactic treatments were applied.A profilaxia dental é uma prática comum para a remoção de placa bacteriana e outros indutos que dificultam a realização dos procedimentos restauradores. Entretanto, como efeito secundário à limpeza, pode-se ter uma superfície mais rugosa e sujeita a manchamentos e degradações. O presente estudo avaliou os efeitos de três técnicas de profilaxia - jato de bicarbonato de sódio, pasta de pedra

  3. Sol-gel-graphene-based fabric-phase sorptive extraction for cow and human breast milk sample cleanup for screening bisphenol A and residual dental restorative material before analysis by HPLC with diode array detection.

    Science.gov (United States)

    Samanidou, Victoria; Filippou, Olga; Marinou, Eirini; Kabir, Abuzar; Furton, Kenneth G

    2017-06-01

    Fabric-phase sorptive extraction has already been recognized as a simple and green alternative to the conventional sorbent-based sorptive microextraction techniques, using hybrid organic-inorganic sorbent coatings chemically bonded to a flexible fabric surface. Herein, we have investigated the synergistic combination of the advanced material properties offered by sol-gel graphene sorbent and the simplicity of Fabric phase sorptive extraction approach in selectively extracting bisphenol A and residual monomers including bisphenol A glycerolatedimethacrylate, urethane dimethacrylate, and triethylene glycol dimethacrylate derived dental restorative materials from cow and human breast milk samples. Different coatings were evaluated. Final method development employed sol-gel graphene coated media. The main experimental parameters influencing extraction of the compounds, such as sorbent chemistry used, sample loading conditions, elution solvent, sorption stirring time, elution time, impact of protein precipitation, amount of sample, and matrix effect, were investigated and optimized. Absolute recovery values from standard solutions were 50% for bisphenol A, 78% for T triethylene glycol dimethacrylate, 110% for urethane dimethacrylate, and 103% for bisphenol A glycerolatedimethacrylate, while respective absolute recovery values from milk were 30, 52, 104, and 42%. Method validation was performed according to European Decision 657/2002/EC in terms of selectivity, sensitivity, linearity, accuracy, and precision. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Dental caries, restorations and extractions by dental caries in first permanent molars. Clinical and radiographic study

    International Nuclear Information System (INIS)

    Aguiar, Sandra Maria H.C. Avila de; Santos Pinto, Ruy dos

    1996-01-01

    This research analyse by clinical and radiographic study, dental caries, restorations and extractions in 1.600 first permanent molars, from 400 children, both sexes, aged 5 to 13 years old, assisted in the Children's Clinic, Faculdade de Odontologia de Aracatuba, UNESP, in 1994. (author)

  5. Antibacterial agents in composite restorations for the prevention of dental caries.

    Science.gov (United States)

    Pereira-Cenci, Tatiana; Cenci, Maximiliano S; Fedorowicz, Zbys; Azevedo, Marina

    2013-12-17

    Dental caries is a multifactorial disease in which the fermentation of food sugars by bacteria from the biofilm (dental plaque) leads to localised demineralisation of tooth surfaces, which may ultimately result in cavity formation. Resin composites are widely used in dentistry to restore teeth. These restorations can fail for a number of reasons, such as secondary caries, and restorative material fracture and other minor reasons. From these, secondary caries, which are caries lesions developed adjacent to restorations, is the main cause for restorations replacement. The presence of antibacterials in both the filling material and the bonding systems would theoretically be able to affect the initiation and progression of caries adjacent to restorations. This is an update of the Cochrane review published in 2009. To assess the effects of antibacterial agents incorporated into composite restorations for the prevention of dental caries. We searched the following electronic databases: the Cochrane Oral Health Group's Trials Register (to 23 July 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 6), MEDLINE via OVID (1946 to 23 July 2013) and EMBASE via OVID (1980 to 23 July 2013). We searched the US National Institutes of Health Trials Register (http://clinicaltrials.gov), the metaRegister of Controlled Trials (www.controlled-trials.com) and the World Health Organization International Clinical Trials Registry platform (www.who.int/trialsearch) for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. Randomised controlled trials comparing resin composite restorations containing antibacterial agents with composite restorations not containing antibacterial agents. Two review authors conducted screening of studies in duplicate and independently, and although no eligible trials were identified, the two authors had planned to extract data independently and

  6. [Research on the aging of all-ceramics restoration materials].

    Science.gov (United States)

    Zhang, Dongjiao; Chen, Xinmin

    2011-10-01

    All-ceramic crowns and bridges have been widely used for dental restorations owing to their excellent functionality, aesthetics and biocompatibility. However, the premature clinical failure of all-ceramic crowns and bridges may easily occur when they are subjected to the complex environment of oral cavity. In the oral environment, all-ceramic materials are prone to aging. Aging can lead all-ceramic materials to change color, to lower bending strength, and to reduce anti-fracture toughness. There are many factors affecting the aging of the all-ceramic materials, for example, the grain size, the type of stabilizer, the residual stress and the water environment. In order to analyze the aging behavior, to optimize the design of all-ceramic crowns and bridges, and to evaluate the reliability and durability, we review in this paper recent research progress of aging behavior for all-ceramics restoration materials.

  7. Tribology of dental materials: a review

    International Nuclear Information System (INIS)

    Zhou, Z R; Zheng, J

    2008-01-01

    The application of tribology in dentistry is a growing and rapidly expanding field. Intensive research has been conducted to develop an understanding of dental tribology for successful design and selection of artificial dental materials. In this paper, the anatomy and function of human teeth is presented in brief, three types of current artificial dental materials are summarized, and their advantages and disadvantages, as well as typical clinical applications, are compared based on the literature. Possible tribological damage of tooth structure, which is induced by complex interfacial motion, and friction-wear test methods are reported. According to results obtained by the authors and from the literature, the main progress in the area of dental tribology on both natural teeth and artificial dental materials is reviewed. Problems and challenges are discussed and future research directions for dental tribology are recommended. (topical review)

  8. Tribology of dental materials: a review

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Z R; Zheng, J [Tribology Research Institute, Key Laboratory for Advanced Technology of Materials of Ministry of Education, Southwest Jiaotong University, Chengdu 610031 (China)], E-mail: zrzhou@home.swjtu.edu.cn

    2008-06-07

    The application of tribology in dentistry is a growing and rapidly expanding field. Intensive research has been conducted to develop an understanding of dental tribology for successful design and selection of artificial dental materials. In this paper, the anatomy and function of human teeth is presented in brief, three types of current artificial dental materials are summarized, and their advantages and disadvantages, as well as typical clinical applications, are compared based on the literature. Possible tribological damage of tooth structure, which is induced by complex interfacial motion, and friction-wear test methods are reported. According to results obtained by the authors and from the literature, the main progress in the area of dental tribology on both natural teeth and artificial dental materials is reviewed. Problems and challenges are discussed and future research directions for dental tribology are recommended. (topical review)

  9. Rubber dam may increase the survival time of dental restorations.

    Science.gov (United States)

    Keys, William; Carson, Susan J

    2017-03-01

    Data sourcesCochrane Oral Health's Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Embase, LILACS, SciELO, Chinese BioMedical Literature Database, VIP, China National Knowledge Infrastructure, ClinicalTrials.gov, World Health Organization International Clinical Trials Registry Platform, OpenGrey and Sciencepaper Online databases. Handsearches in a number of journals.Study selectionRandomised controlled trials, including split-mouth studies assessing the effects of rubber dam isolation for restorative treatments in dental patients.Data extraction and synthesisTwo review authors independently screened the results of the electronic searches, extracted data and assessed the risk of bias of the included studies.ResultsFour studies involving a total of 1,270 patients were included. The studies were at high risk of bias. One trial was excluded from the analysis due to inconsistencies in the presented data. Restorations had a significantly higher survival rate in the rubber dam isolation group compared to the cotton roll isolation group at six months in participants receiving composite restorative treatment of non-carious cervical lesions (risk ratio (RR) 1.19, 95% confidence interval (CI) 1.04 to 1.37, very low-quality evidence). The rubber dam group had a lower risk of failure at two years in children undergoing proximal atraumatic restorative treatment in primary molars (hazard ratio (HR) 0.80, 95% CI 0.66 to 0.97, very low-quality evidence). One trial reported limited data showing that rubber dam usage during fissure sealing might shorten the treatment time. None of the included studies mentioned adverse effects or reported the direct cost of the treatment, or the level of patient acceptance/satisfaction. There was also no evidence evaluating the effects of rubber dam usage on the quality of the restorations.ConclusionsWe found some very low-quality evidence, from single studies, suggesting that rubber dam usage in dental direct

  10. Wear characteristics of current aesthetic dental restorative CAD/CAM materials: two-body wear, gloss retention, roughness and Martens hardness.

    Science.gov (United States)

    Mörmann, Werner H; Stawarczyk, Bogna; Ender, Andreas; Sener, Beatrice; Attin, Thomas; Mehl, Albert

    2013-04-01

    This study determined the two-body wear and toothbrushing wear parameters, including gloss and roughness measurements and additionally Martens hardness, of nine aesthetic CAD/CAM materials, one direct resin-based nanocomposite plus that of human enamel as a control group. Two-body wear was investigated in a computer-controlled chewing simulator (1.2 million loadings, 49N at 1.7Hz; 3000 thermocycles 5/50°C). Each of the 11 groups consisted of 12 specimens and 12 enamel antagonists. Quantitative analysis of wear was carried out with a 3D-surface analyser. Gloss and roughness measurements were evaluated using a glossmeter and an inductive surface profilometer before and after abrasive toothbrushing of machine-polished specimens. Additionally Martens hardness was measured. Statistically significant differences were calculated with one-way ANOVA (analysis of variance). Statistically significant differences were found for two-body wear, gloss, surface roughness and hardness. Zirconium dioxide ceramics showed no material wear and low wear of the enamel antagonist. Two-body wear of CAD/CAM-silicate and -lithium disilicate ceramics, -hybrid ceramics and -nanocomposite as well as direct nanocomposite did not differ significantly from that of human enamel. Temporary polymers showed significantly higher material wear than permanent materials. Abrasive toothbrushing significantly reduced gloss and increased roughness of all materials except zirconium dioxide ceramics. Gloss retention was highest with zirconium dioxide ceramics, silicate ceramics, hybrid ceramics and nanocomposites. Temporary polymers showed least gloss retention. Martens hardness differed significantly among ceramics, between ceramics and composites, and between resin composites and acrylic block materials as well. All permanent aesthetic CAD/CAM block materials tested behave similarly or better with respect to two-body wear and toothbrushing wear than human enamel, which is not true for temporary polymer CAD

  11. Optical investigations of various polymeric materials used in dental technology

    Science.gov (United States)

    Negrutiu, Meda Lavinia; Sinescu, Cosmin; Topala, Florin Ionel; Ionita, Ciprian; Goguta, Luciana; Marcauteanu, Corina; Rominu, Mihai; Podoleanu, Adrian Gh.

    2011-10-01

    Dental prosthetic restorations have to satisfy high stress as well as aesthetic requirements. In order to avoid deficiencies of dental prostheses, several alternative systems and procedures were imagined, directly related to the material used and also to the manufacturing technology. Increasing the biomechanical comportment of polymeric materials implies fiber reinforcing. The different fibers reinforcing products made very difficult the evaluation of their performances and biomechanical properties analysis. There are several known methods which are used to assess the quality of dental prostheses, but most are invasive. These lead to the destruction of the samples and often no conclusion could be drawn in the investigated areas of interest. Using a time domain en-face OCT system, we have recently demonstrated real time thorough evaluation of quality of various dental treatments. The aim of this study was to assess the quality of various polymeric materials used in dental technology and to validate the en face OCT imagistic evaluation of polymeric dental prostheses by using scanning electron microscopy (SEM) and microcomputer tomography (μCT). SEM investigations evidenced the nonlinear aspect of the interface between the polymeric material and the fiber reinforcement and materials defects in some samples. The results obtained by microCT revealed also some defects inside the polymeric materials and at the interfaces with the fiber reinforcement. The advantages of the OCT method consist in non-invasiveness and high resolution. In addition, en face OCT investigations permit visualization of the more complex stratified structure at the interface between the polymeric material and the fiber reinforcement.

  12. Scattering and Absorption Properties of Biomaterials for Dental Restorative Applications

    Science.gov (United States)

    Fernandez-Oliveras, A.; Rubiño, M.; Pérez, M. M.

    2013-08-01

    The physical understanding of the optical properties of dental biomaterials is mandatory for their final success in restorative applications.Light propagation in biological media is characterized by the absorption coefficient, the scattering coefficient, the scattering phase function,the refractive index, and the surface conditions (roughness). We have employed the inverse adding-doubling (IAD) method to combine transmittance and reflectance measurements performed using an integrating-sphere setup with the results of the previous scattering-anisotropygoniometric measurements. This has led to the determination of the absorption and the scattering coefficients. The aim was to optically characterize two different dental-resin composites (nanocomposite and hybrid) and one type of zirconia ceramic, and comparatively study them. The experimental procedure was conducted under repeatability conditions of measurement in order to determine the uncertainty associated to the optical properties of the biomaterials. Spectral variations of the refraction index and the scattering anisotropy factor were also considered. The whole experimental procedure fulfilled all the necessary requirements to provide optical-property values with lower associated uncertainties. The effective transport coefficient presented a similar spectral behavior for the two composites but completely different for the zirconia ceramic. The results demonstrated that the scattering anisotropy exerted a clearly distinct impact on the optical properties of the zirconia ceramic compared with those of the dental-resin composites.

  13. Assessment of Heat Hazard during the Polymerization of Selected Light-Sensitive Dental Materials

    OpenAIRE

    Janeczek, Maciej; Herman, Katarzyna; Fita, Katarzyna; Dudek, Krzysztof; Kowalczyk-Zaj?c, Ma?gorzata; Czajczy?ska-Waszkiewicz, Agnieszka; Piesiak-Pa?czyszyn, Dagmara; Kosior, Piotr; Dobrzy?ski, Maciej

    2016-01-01

    Introduction. Polymerization of light-cured dental materials used for restoration of hard tooth tissue may lead to an increase in temperature that may have negative consequence for pulp vitality. Aim. The aim of this study was to determine maximum temperatures reached during the polymerization of selected dental materials, as well as the time that is needed for samples of sizes similar to those used in clinical practice to reach these temperatures. Materials and Methods. The study involved fo...

  14. Mercury release from dental amalgam restorations after magnetic resonance imaging and following mobile phone use

    Energy Technology Data Exchange (ETDEWEB)

    Mortazavi, S M.J., [Shiraz Univ. of Medical Sciences (Iran, Islamic Republic of). School of Paramedical Sciences; Daiee, E; Yazdi, A; Khiabani, K; Kavousi, A [Rafsanjan Univ. of Medical Sciences (Iran, Islamic Republic of). Dentistry School; Vazirinejad, R [Rafsanjan Univ. of Medical Sciences (Iran, Islamic Republic of). School of Medicine, Community Medicine Dept.; Behnejad, B [Rafsanjan Univ. of Medical Sciences (Iran, Islamic Republic of). School of Paramedical Sciences, Radiologic Technology Dept.; Ghasemi, M [Mashad University of Medical Science (Iran, Islamic Republic of). Imam Reza Hospital, Toxicology Laboratory; Mood, M Balali [Mashad Univ. of Medical Science (Iran, Islamic Republic of). Imam Reza Hospital, Medical Toxicology Research Center

    2008-07-01

    Background: Mercury or Hydrargyrum (Hg) is the most non-radioactive toxic element. Dental amalgam is made up of 50% mercury. Exposure to electromagnetic fields of magnetic resonance imaging (MRI) and microwave radiation emitted from mobile phone use may increase the emission of mercury from dental amalgam fillings. It was thus aimed to study the effects of exposure to MRI and mobile phone use on the mercury release from dental amalgam restorations. Materials and Methods: Following approval of the University Medical Ethics Committee and the informed consents of the subjects, two different studies were undertaken. A-MRI: - Thirty patients (27 F, 3 M) aged 18 to 48 years who had been referred to MRI department of Ali-ebn Abitaleb Teaching Hospital and had at least four amalgam restorated teeth, were investigated. Five ml stimulated saliva was collected just before and after MRI. The magnetic flux density was 0.23 T, and the duration of exposure of patients to magnetic field was 30 minutes. B-Mobile phone Use: Fourteen female healthy University students aged 19-23 years, who had not used mobile phones before the study and did not have any previous amalgam restorations but had decays in at least four teeth were investigated. Their urine samples were collected before amalgam restoration, and at days 1, 2, 3 and 4 after restoration. Dental amalgam restoration was performed for all 14 students (2 molars on one side, one class I and one class II restorations with identical volume and surface area of the amalgam fillings). The students randomly divided into two equal groups. The test group students were exposed to microwave radiation emitted from a Nokia 3310 mobile phone (SAR=0.96 W kg{sup -1}) that was operated in talk mode for 15 min every day at days 1-4 after restoration. The other seven female age matched students who served as controls sham exposed to microwave radiation. For each subject, a questionnaire regarding their possible sources of exposure to electromagnetic

  15. Mercury release from dental amalgam restorations after magnetic resonance imaging and following mobile phone use

    International Nuclear Information System (INIS)

    Mortazavi, S.M.J.; Daiee, E.; Yazdi, A.; Khiabani, K.; Kavousi, A.; Vazirinejad, R.; Behnejad, B.; Ghasemi, M.; Mood, M. Balali

    2008-01-01

    Background: Mercury or Hydrargyrum (Hg) is the most non-radioactive toxic element. Dental amalgam is made up of 50% mercury. Exposure to electromagnetic fields of magnetic resonance imaging (MRI) and microwave radiation emitted from mobile phone use may increase the emission of mercury from dental amalgam fillings. It was thus aimed to study the effects of exposure to MRI and mobile phone use on the mercury release from dental amalgam restorations. Materials and Methods: Following approval of the University Medical Ethics Committee and the informed consents of the subjects, two different studies were undertaken. A-MRI: - Thirty patients (27 F, 3 M) aged 18 to 48 years who had been referred to MRI department of Ali-ebn Abitaleb Teaching Hospital and had at least four amalgam restorated teeth, were investigated. Five ml stimulated saliva was collected just before and after MRI. The magnetic flux density was 0.23 T, and the duration of exposure of patients to magnetic field was 30 minutes. B-Mobile phone Use: Fourteen female healthy University students aged 19-23 years, who had not used mobile phones before the study and did not have any previous amalgam restorations but had decays in at least four teeth were investigated. Their urine samples were collected before amalgam restoration, and at days 1, 2, 3 and 4 after restoration. Dental amalgam restoration was performed for all 14 students (2 molars on one side, one class I and one class II restorations with identical volume and surface area of the amalgam fillings). The students randomly divided into two equal groups. The test group students were exposed to microwave radiation emitted from a Nokia 3310 mobile phone (SAR=0.96 W kg -1 ) that was operated in talk mode for 15 min every day at days 1-4 after restoration. The other seven female age matched students who served as controls sham exposed to microwave radiation. For each subject, a questionnaire regarding their possible sources of exposure to electromagnetic

  16. Assessment of exposures and potential risks to the US adult population from wear (attrition and abrasion) of gold and ceramic dental restorations.

    Science.gov (United States)

    Richardson, G Mark; Clemow, Scott R; Peters, Rachel E; James, Kyle J; Siciliano, Steven D

    2016-01-01

    Little has been published on the chemical exposures and risks of dental restorative materials other than from dental amalgam and composite resins. Here we provide the first exposure and risk assessment for gold (Au) alloy and ceramic restorative materials. Based on the 2001-2004 US National Health and Nutrition Examination Survey (NHANES), we assessed the exposure of US adults to the components of Au alloy and ceramic dental restorations owing to dental material wear. Silver (Ag) is the most problematic component of Au alloy restorations, owing to a combination of toxicity and proportional composition. It was estimated that adults could possess an average of four tooth surfaces restored with Au alloy before exceeding, on average, the reference exposure level (REL) for Ag. Lithium (Li) is the most problematic component of dental ceramics. It was estimated that adults could possess an average of 15 tooth surfaces restored with ceramics before exceeding the REL for Li. Relative risks of chemical exposures from dental materials decrease in the following order: Amalgam>Au alloys>ceramics>composite resins.

  17. Effect of type of cavity preparation (bur,Er:YAG laser) and restorative materials on prevention of caries lesion

    OpenAIRE

    Masumeh Hasani Tabatabaei; Sakineh Arami; Fatemeh Khajavi; Zohreh Moradi

    2017-01-01

    Background and Aims: Despite the reduction of incidence of dental caries in recent years, this disease is common and many efforts were conducted to decrease the prevalence of dental caries. On the other hand secondary caries lesions are the main reason for replacement of direct restorations. Therefore, the aim of the current study was to evaluate suitable methods of preparation and restorative materials to reduce caries recurrence. Materials and Methods: In this experimental study, eighty...

  18. Evaluation of effects of ionizing radiation on the titanium used in dental restorations

    International Nuclear Information System (INIS)

    Maio, Mireia Florencio; Santos, Adimir dos; Fernandes, Marco A.R.

    2009-01-01

    The purpose of this work consisted of quantitative studies of the effects caused by ionizing radiation on titanium, a material used in dental restorations. Titanium is used to mitigate the deleterious effects of radiotherapy when patients with tumors in head and neck, seen when the teeth are restored within in the field of radiation. Samples were submitted to X-radiation beams from 6 and 10 Mega - Volt (MV) from a linear accelerator, VARIAN 2100C model. The samples were analyzed by X-ray fluorescence techniques to compare the chemical composition before and after the irradiation. Sample dose measurements were performed employing Geiger-Mueller detectors and the ionization chamber in order to verify any residual radiation in the samples. The samples were also analyzed by gamma spectrometry by a HPGe detector. These tests were performed to determine small changes in the composition in the samples due to the radiation interaction. The results of this study may encourage the development of new research for alternative materials in dental restorations that can contribute to improve the quality of life of those patients with tumors of the mouth. (author)

  19. Evaluation of effects of ionizing radiation on the glass ionomer used in dental restorations

    International Nuclear Information System (INIS)

    Maio, F.M.; Santos, A.; Fernandes, M.A.R.

    2009-01-01

    The purpose of this work consisted of quantitative studies of the effects caused by ionizing radiation on glass ionomer, a material used in dental restorations. Glass ionomer is used to mitigate the deleterious effects of radiotherapy when patients with tumors in head and neck, seen when the teeth are restored within in the field of radiation. Samples were submitted to X-radiation beams from 6 MV from a linear accelerator, VARIAN 2100C model. The samples were analyzed by X-ray fluorescence techniques to compare the chemical composition before and after the irradiation. Sample dose measurements were performed employing Geiger-Mueller detectors and the ionization chamber in order to verify any residual radiation in the samples. The samples were also analyzed by gamma spectrometry by a HPGe detector. These tests were performed to determine small changes in the composition in the samples due to the radiation interaction. The results of this study may encourage the development of new research for alternative materials in dental restorations that can contribute to improve the quality of life of those patients with tumors of the mouth. (author)

  20. Liquid crystalline epoxy nanocomposite material for dental application.

    Science.gov (United States)

    Tai, Yun-Yuan; Hsu, Sheng-Hao; Chen, Rung-Shu; Su, Wei-Fang; Chen, Min-Huey

    2015-01-01

    Novel liquid crystalline epoxy nanocomposites, which exhibit reduced polymerization shrinkage and effectively bond to tooth structures, can be applied in esthetic dentistry, including core and post systems, direct and indirect restorations, and dental brackets. The purposes of this study were to investigate the properties of liquid crystalline epoxy nanocomposites including biocompatibility, microhardness, and frictional forces of bracket-like blocks with different filler contents for further clinical applications. In this study, we evaluated liquid crystalline epoxy nanocomposite materials that exhibited various filler contents, by assessing their cell activity performance using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and their microhardness with or without thermocycling. We also evaluated the frictional force between bracket-like duplicates and commercially available esthetic bracket systems using Instron 5566. The liquid crystalline epoxy nanocomposite materials showed good biocompatibility. The materials having high filler content demonstrated greater microhardness compared with commercially available bracket materials, before and after the thermocycling treatment. Thus, manufacturing processes are important to reduce frictional force experienced by orthodontic brackets. The microhardness of the bracket-like blocks made by our new material is superior to the commercially available brackets, even after thermocycling. Our results indicate that the evaluated liquid crystalline epoxy nanocomposite materials are of an appropriate quality for application in dental core and post systems and in various restorations. By applying technology to refine manufacturing processes, these new materials could also be used to fabricate esthetic brackets for orthodontic treatment. Copyright © 2014. Published by Elsevier B.V.

  1. Structural, Surface, in vitro Bacterial Adhesion and Biofilm Formation Analysis of Three Dental Restorative Composites

    Directory of Open Access Journals (Sweden)

    Maria T. Azam

    2015-06-01

    Full Text Available This study was conducted to investigate the relationship between dental materials and bacterial adhesion on the grounds of their chemical composition and physical properties. Three commercially available dental restorative materials (Filtek™Z350, Filtek™P90 and Spectrum®TPH® were structurally analyzed and their wettability and surface roughness were evaluated by using Fourier Transform Infrared Spectroscopy, Contact Angle Measurement and Atomic Force Microscopy, respectively. These materials were molded into discs and tested with three bacterial strains (Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia for microbial attachment. The bacterial adhesion was observed at different time intervals, i.e., 0 h, 8 h, 24 h, 48 h and 72 h, along with Colony Forming Unit Count and Optical Density measurement of the media. It was found that all materials showed a degree of conversion with time intervals, i.e., 0 h, 8 h, 24 h, 48 h and 72 h, which led to the availability of functional groups (N–H and C–H that might promote adhesion. The trend in difference in the extent of bacterial adhesion can be related to particle size, chemical composition and surface wettability of the dental materials.

  2. Synthetic Light-Curable Polymeric Materials Provide a Supportive Niche for Dental Pulp Stem Cells.

    Science.gov (United States)

    Vining, Kyle H; Scherba, Jacob C; Bever, Alaina M; Alexander, Morgan R; Celiz, Adam D; Mooney, David J

    2018-01-01

    Dental disease annually affects billions of patients, and while regenerative dentistry aims to heal dental tissue after injury, existing polymeric restorative materials, or fillings, do not directly participate in the healing process in a bioinstructive manner. There is a need for restorative materials that can support native functions of dental pulp stem cells (DPSCs), which are capable of regenerating dentin. A polymer microarray formed from commercially available monomers to rapidly identify materials that support DPSC adhesion is used. Based on these findings, thiol-ene chemistry is employed to achieve rapid light-curing and minimize residual monomer of the lead materials. Several triacrylate bulk polymers support DPSC adhesion, proliferation, and differentiation in vitro, and exhibit stiffness and tensile strength similar to existing dental materials. Conversely, materials composed of a trimethacrylate monomer or bisphenol A glycidyl methacrylate, which is a monomer standard in dental materials, do not support stem cell adhesion and negatively impact matrix and signaling pathways. Furthermore, thiol-ene polymerized triacrylates are used as permanent filling materials at the dentin-pulp interface in direct contact with irreversibly injured pulp tissue. These novel triacrylate-based biomaterials have potential to enable novel regenerative dental therapies in the clinic by both restoring teeth and providing a supportive niche for DPSCs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. IN VITRO TESTING – AN ESENTIAL METHOD FOR EVALUATING THE PERFORMANCE OF DENTAL MATERIALS AND DEVICES

    Directory of Open Access Journals (Sweden)

    Anca VIŢALARIU

    2015-06-01

    Full Text Available Dentistry is unique among biomaterials specialties as to the large variety of materials used, and nature of the challenges they must resist. Intra-oral service demands materials adapted to a warm and moist environment, resisting the attack of digestive acids and enzymes. The materials subjected to mechanical forces should preserve their strength, fatigue and wear characteristics, for accomplishing their function. The wide range of materials available for restorative dentistry demands knowledge of their relative strengths and trade-offs, and offers the opportunity for many interesting lines of research. The spectrum extensively ranges from elastic impression materials to extremely stiff metal and ceramic appliances, so that familiarity with a variety of mechanical testing situations is required from a well-rounded dental materials laboratory. Evaluating the mechanical and wear characteristics of dental restorative materials and analyzing the durability of adhesives is critical to the development of improved dental devices

  4. Evaluation of the dental structure loss produced during maintenance and replacement of occlusal amalgam restorations

    Directory of Open Access Journals (Sweden)

    Fernanda Sardenberg

    2008-09-01

    Full Text Available The aim of this in vitro study was to evaluate four different approaches to the decision of changing or not defective amalgam restorations in first primary molar teeth concerning the loss of dental structure. Ditched amalgam restorations (n = 11 were submitted to four different treatments, as follows: Control group - polishing and finishing of the restorations were carried out; Amalgam group - the ditched amalgam restorations were replaced by new amalgam restorations; Composite resin group - the initial amalgam restorations were replaced by composite resin restorations; Flowable resin group - the ditching around the amalgam restorations was filled with flowable resin. Images of the sectioned teeth were made and the area of the cavities before and after the procedures was determined by image analysis software to assess structural loss. The data were submitted to ANOVA complemented by the Student Newman Keuls test (p < 0.05. The cavities in all the groups presented significantly greater areas after the procedures. However, the amalgam group showed more substantial dental loss. The other three groups presented no statistically significant difference in dental structure loss after the re-treatments. Thus, replacing ditched amalgam restorations by other similar restorations resulted in a significant dental structure loss while maintaining them or replacing them by resin restorations did not result in significant loss.

  5. An evaluation of dental operative simulation materials.

    Science.gov (United States)

    He, Li-Hong; Foster Page, Lyndie; Purton, David

    2012-01-01

    The study was to evaluate the performance of different materials used in dental operative simulation and compare them with those of natural teeth. Three typical phantom teeth materials were compared with extracted permanent teeth by a nanoindentation system and evaluated by students and registered dentists on the drilling sensation of the materials. Moreover, the tool life (machinability) of new cylindrical diamond burs on cutting the sample materials was tested and the burs were observed. Although student and dentist evaluations were scattered and inconclusive, it was found that elastic modulus (E) and hardness (H) were not the main factors in determining the drilling sensation of the materials. The sensation of drilling is a reflection of cutting force and power consumption.An ideal material for dental simulation should be able to generate similar drilling resistance to that of natural tooth, which is the machinability of the material.

  6. Repair or replacement of defective restorations by dentists in The Dental Practice-Based Research Network

    DEFF Research Database (Denmark)

    Gordan, Valeria V; Riley, Joseph L; Geraldeli, Saulo

    2012-01-01

    The authors aimed to determine whether dentists in practices belonging to The Dental Practice-Based Research Network (DPBRN) were more likely to repair or to replace a restoration that they diagnosed as defective; to quantify dentists' specific reasons for repairing or replacing restorations......; and to test the hypothesis that certain dentist-, patient- and restoration-related variables are associated with the decision between repairing and replacing restorations....

  7. Presence and leaching of bisphenol a (BPA) from dental materials

    Science.gov (United States)

    Becher, Rune; Wellendorf, Hanne; Sakhi, Amrit Kaur; Samuelsen, Jan Tore; Thomsen, Cathrine; Bølling, Anette Kocbach; Kopperud, Hilde Molvig

    2018-01-01

    Abstract BPA has been reported to leach from some resin based dental restorative materials and materials used for orthodontic treatment. To confirm and update previous findings, especially in light of the new temporary lower threshold value for tolerable daily BPA intake, we have investigated the leaching of BPA from 4 composite filling materials, 3 sealants and 2 orthodontic bonding materials. The materials were either uncured and dissolved in methanol or cured. The cured materials were kept in deionized water for 24 hours or 2 weeks. Samples were subsequently analyzed by ultra-performance liquid chromatography coupled to mass spectrometry (UPLC-MS-MS). The composite filling material Tetric EvoFlow® and the fissure sealant DELTON® showed significantly higher levels of BPA leaching compared to control samples for all test conditions (uncured, 24 h leaching and 2 weeks leaching). There were no significant differences in amount of leached BPA for any of the tested materials after 24 hours compared to 2 weeks. These results show that BPA is still released from some dental materials despite the general concern about potential adverse effects of BPA. However, the amounts of BPA were relatively low and most likely represent a very small contribution to the total BPA exposure. PMID:29868625

  8. Use of digital impression systems with intraoral scanners for fabricating restorations and fixed dental prostheses.

    Science.gov (United States)

    Takeuchi, Yoshimasa; Koizumi, Hiroyasu; Furuchi, Mika; Sato, Yohei; Ohkubo, Chikahiro; Matsumura, Hideo

    2018-01-01

    Accurate impressions are essential in fabri-cating dental restorations and fixed dental prostheses. During the last decade, digital impression systems have improved substantially. This review discusses the accuracy of digital impression systems for fabrication of dental restorations and fixed dental prostheses. A literature search in PubMed was performed for the period from July 2010 through June 2017. The search keywords were Cerec, digital impression, direct digitalization, indirect digitalization, and intraoral scanner. Only relevant studies are summarized and discussed in this review. In general, the latest systems have considerably reduced the time required for impression making, and the accuracy and marginal fit of digital impression systems have recently improved. Restorations and fixed dental prostheses fabricated with currently available digital impression systems and intraoral scanners exhibit clinically acceptable ranges of marginal gap in both direct and indirect procedures.

  9. Restoration of noncarious tooth defects by dentists in The Dental Practice-Based Research Network

    DEFF Research Database (Denmark)

    Nascimento, Marcelle M; Gordan, Valeria V; Qvist, Vibeke

    2011-01-01

    The authors conducted a study to quantify the reasons for restoring noncarious tooth defects (NCTDs) by dentists in The Dental Practice-Based Research Network (DPBRN) and to assess the tooth, patient and dentist characteristics associated with those reasons....

  10. Longevity of posterior composite restorations: not only a matter of materials.

    Science.gov (United States)

    Demarco, Flávio F; Corrêa, Marcos B; Cenci, Maximiliano S; Moraes, Rafael R; Opdam, Niek J M

    2012-01-01

    Resin composites have become the first choice for direct posterior restorations and are increasingly popular among clinicians and patients. Meanwhile, a number of clinical reports in the literature have discussed the durability of these restorations over long periods. In this review, we have searched the dental literature looking for clinical trials investigating posterior composite restorations over periods of at least 5 years of follow-up published between 1996 and 2011. The search resulted in 34 selected studies. 90% of the clinical studies indicated that annual failure rates between 1% and 3% can be achieved with Class I and II posterior composite restorations depending on several factors such as tooth type and location, operator, and socioeconomic, demographic, and behavioral elements. The material properties showed a minor effect on longevity. The main reasons for failure in the long term are secondary caries, related to the individual caries risk, and fracture, related to the presence of a lining or the strength of the material used as well as patient factors such as bruxism. Repair is a viable alternative to replacement, and it can increase significantly the lifetime of restorations. As observed in the literature reviewed, a long survival rate for posterior composite restorations can be expected provided that patient, operator and materials factors are taken into account when the restorations are performed. Copyright © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  11. Characteristics Identified for Success by Restorative Dental Science Department Chairpersons.

    Science.gov (United States)

    Wee, Alvin G; Weiss, Robert O; Wichman, Christopher S; Sukotjo, Cortino; Brundo, Gerald C

    2016-03-01

    The primary aim of this study was to determine the characteristics that current chairpersons in restorative dentistry, general dentistry, prosthodontics, and operative dentistry departments in U.S. dental schools feel are most relevant in contributing to their success. The secondary aim was to determine these individuals' rankings of the importance of a listed set of characteristics for them to be successful in their position. All 82 current chairs of the specified departments were invited to respond to an electronic survey. The survey first asked respondents to list the five most essential characteristics to serve as chair of a department and to rank those characteristics based on importance. Participants were next given a list of ten characteristics in the categories of management and leadership and, without being aware of the category of each individual item, asked to rank them in terms of importance for their success. A total of 39 chairpersons completed the survey (47.6% response rate; 83.3% male and 16.2% female). In section one, the respondents reported that leadership, vision, work ethic, integrity, communication, and organization were the most essential characteristics for their success. In section two, the respondents ranked the leadership characteristics as statistically more important than the management characteristics (psuccessful in their positions.

  12. Titanium Nitride and Nitrogen Ion Implanted Coated Dental Materials

    Directory of Open Access Journals (Sweden)

    David W. Berzins

    2012-07-01

    Full Text Available Titanium nitride and/or nitrogen ion implanted coated dental materials have been investigated since the mid-1980s and considered in various applications in dentistry such as implants, abutments, orthodontic wires, endodontic files, periodontal/oral hygiene instruments, and casting alloys for fixed restorations. Multiple methodologies have been employed to create the coatings, but detailed structural analysis of the coatings is generally lacking in the dental literature. Depending on application, the purpose of the coating is to provide increased surface hardness, abrasion/wear resistance, esthetics, and corrosion resistance, lower friction, as well as greater beneficial interaction with adjacent biological and material substrates. While many studies have reported on the achievement of these properties, a consensus is not always clear. Additionally, few studies have been conducted to assess the efficacy of the coatings in a clinical setting. Overall, titanium nitride and/or nitrogen ion implanted coated dental materials potentially offer advantages over uncoated counterparts, but more investigation is needed to document the structure of the coatings and their clinical effectiveness.

  13. A study of dentists’ preferences for the restoration of shortened dental arches with partial dentures

    Science.gov (United States)

    Nassani, Mohammad Zakaria; Ibraheem, Shukran; Al-Hallak, Khaled Rateb; Ali El Khalifa, Mohammed Othman; Baroudi, Kusai

    2015-01-01

    Objective: This study aimed to use a utility method in order to assess dentists’ preferences for the restoration of shortened dental arches (SDAs) with partial dentures. Also, the impact of patient age and length of the SDA on dentists’ preferences for the partial dentures was investigated. Materials and Methods: Totally, 104 subjects holding a basic degree in dentistry and working as staff members in a private dental college in Saudi Arabia were interviewed and presented with 12 scenarios for patients of different ages and mandibular SDAs of varying length. Participants were asked to indicate on a standardized visual analog scale how they would value the health of the patient's mouth if the mandibular SDAs were restored with cobalt-chromium removable partial dentures (RPDs). Results: With a utility value of 0.0 representing the worst possible health state for a mouth and 1.0 representing the best, dentists’ average utility value of the RPD for the SDAs was 0.49 (sd= 0.15). Mean utility scores of the RPDs across the 12 SDA scenarios ranged between 0.35 and 0.61. RPDs that restored the extremely SDAs attracted the highest utility values and dentists’ utility of the RPD significantly increased with the increase in the number of missing posterior teeth. No significant differences in dentists’ mean utility values for the RPD were identified among SDA scenarios for patients of different ages. Conclusion: Restoration of the mandibular SDAs by RPDs is not a highly preferred treatment option among the surveyed group of dentists. Length of the SDA affects dentists’ preferences for the RPD, but patient age does not. PMID:26038647

  14. Evaluating the Reasons of Amalgam Restoration Replacement in Esthetic and Restorative Department of Babol Dental School in 2013-14

    Directory of Open Access Journals (Sweden)

    F Abolghasemzade

    2015-08-01

    Results: Within 263 patients, there were 81(30.8% men and 182(69.2% women. Most patients aged 30-40(42.2%, and were reported to suffer from class Ι dental occlusion(92.4%.The mean DMF was 9.7±2.4 . Lower molars were demonstrated as the most frequent teeth group for replacing amalgam restorations as well as causing secondary caries. Furthermore, secondary caries involved the major causes of amalgam restoration replacement. The most prevalent class for amalgam restoration replacement was class II restorations. It should be noted that secondary caries were most prevalent within class II MO / DO(25 cases(44.6%. Conclusion: The study findings revealed that the most common cause of the restoration replacement involved the secondary caries which was most observed in the Class II restorations.

  15. A comparative evaluation of microleakage of restorations using silorane-based dental composite and methacrylate-based dental composites in Class II cavities: An in vitro study

    Directory of Open Access Journals (Sweden)

    Jambai Sampath Kumar Sivakumar

    2016-01-01

    Full Text Available Aim: The aim of this in vitro study was to evaluate and compare the microleakage of restorations using low shrinkage silorane-based dental composite and methacrylate-based dental composites in Class II cavity at the occlusal and gingival margins. Materials and Methods: Sixty mandibular molars were collected and divided into three experimental groups and one negative control group. Class II slot cavity was prepared on the mesial surface. Experimental groups were restored with Group I: silorane-based microhybrid composite, Group II: methacrylate-based nanohybrid composite, and Group III: Methacrylate-based microhybrid composite, respectively. Group IV: negative control. The samples were thermocycled, root apices were sealed with sticky wax and coated with nail varnish except 1 mm around the restoration. This was followed by immersion in 2% Rhodamine-B dye solution under vacuum at room temperature for 24 h. Then, the samples were sectioned longitudinally in the mesiodistal direction and evaluated under stereomicroscope ×40 magnification. Scoring was done according to the depth of dye penetration in to the cavity. Statistical analysis of the data was done. Results: The results were that no statistically significant difference in the microleakage at the occlusal margin for all the restorative materials, whereas at the gingival margin, silorane-based microhybrid composite showed less microleakage than the methacrylate-based nano- and micro-hybrid composites. Conclusion: In general, silorane-based microhybrid composite had less microleakage among the other materials used in this in vitro study.

  16. Improving the competency of dental hygiene students in detecting dental restorations using quantitative light-induced fluorescence technology.

    Science.gov (United States)

    Oh, Hye-Young; Jung, Hoi-In; Lee, Jeong-Woo; de Jong, Elbert de Josselin; Kim, Baek-Il

    2017-03-01

    The purpose of this study was to determine the usefulness of a quantitative light-induced fluorescence (QLF) technology in detecting dental restorations by comparing the detection ability of dental hygiene students between using conventional visual inspection alone and visual inspection combined with QLF technology. The subjects of this study comprised 92 dental hygiene students. The students assigned to the control group only used white-light images to visually assess the mouth environment, while those in the experimental group additionally used fluorescence images. Using the test results of an experienced inspector as a reference value, the agreement between the reference value and the evaluation results of the students in the experimental and control groups was evaluated using Cohen's kappa and the percentage agreement. The subjects were then classified into groups covering three percentage ranges according to the score distribution and agreement values of the three groups were compared. The percentage agreement was calculated according to the type of dental restorations. The mean kappa value was significantly higher in the experimental group than the control group (0.70 vs 0.60, ptechnology increased by 8% more in the middle and bottom percentage groups than in the top percentage group (ptechnology with conventional visual inspections could improve the ability to detect dental restorations and distinguish sound teeth from aesthetic restorations. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Determination of dose rates from natural radionuclides in dental materials

    International Nuclear Information System (INIS)

    Veronese, I.; Guzzi, G.; Giussani, A.; Cantone, M.C.; Ripamonti, D.

    2006-01-01

    Different types of materials used for dental prosthetics restoration, including feldspathic ceramics, glass ceramics, zirconia-based ceramics, alumina-based ceramics, and resin-based materials, were investigated with regard to content of natural radionuclides by means of thermoluminescence beta dosimetry and gamma spectrometry. The gross beta dose rate from feldspathic and glass ceramics was about ten times higher than the background measurement, whereas resin-based materials generated negligible beta dose rate, similarly to natural tooth samples. The specific activity of uranium and thorium was significantly below the levels found in the period when addition of uranium to dental porcelain materials was still permitted. The high-beta dose levels observed in feldspathic porcelains and glass ceramics are thus mainly ascribable to 4 K, naturally present in these specimens. Although the measured values are below the recommended limits, results indicate that patients with prostheses are subject to higher dose levels than other members of the population. Alumina- and zirconia-based ceramics might be a promising alternative, as they have generally lower beta dose rates than the conventional porcelain materials. However, the dosimetry results, which imply the presence of inhomogeneously distributed clusters of radionuclides in the sample matrix, and the still unsuitable structural properties call for further optimization of these materials

  18. Advancements in all-ceramics for dental restorations and their effect on the wear of opposing dentition

    Science.gov (United States)

    Rashid, Haroon; Sheikh, Zeeshan; Misbahuddin, Syed; Kazmi, Murtaza Raza; Qureshi, Sameer; Uddin, Muhammad Zuhaib

    2016-01-01

    Tooth wear is a process that is usually a result of tooth to tooth and/or tooth and restoration contact. The process of wear essentially becomes accelerated by the introduction of restorations inside the oral cavity, especially in case of opposing ceramic restorations. The newest materials have vastly contributed toward the interest in esthetic dental restorations and have been extensively studied in laboratories. However, despite the recent technological advancements, there has not been a valid in vivo method of evaluation involving clinical wear caused due to ceramics upon restored teeth and natural dentition. The aim of this paper is to review the latest advancements in all-ceramic materials, and their effect on the wear of opposing dentition. The descriptive review has been written after a thorough MEDLINE/PubMed search by the authors. It is imperative that clinicians are aware of recent advancements and that they should always consider the type of ceramic restorative materials used to maintain a stable occlusal relation. The ceramic restorations should be adequately finished and polished after the chair-side adjustment process of occlusal surfaces. PMID:28042280

  19. Bacterial adhesion on direct and indirect dental restorative composite resins: An in vitro study on a natural biofilm.

    Science.gov (United States)

    Derchi, Giacomo; Vano, Michele; Barone, Antonio; Covani, Ugo; Diaspro, Alberto; Salerno, Marco

    2017-05-01

    Both direct and indirect techniques are used for dental restorations. Which technique should be preferred or whether they are equivalent with respect to bacterial adhesion is unclear. The purpose of this in vitro study was to determine the affinity of bacterial biofilm to dental restorative composite resins placed directly and indirectly. Five direct composite resins for restorations (Venus Diamond, Adonis, Optifil, Enamel Plus HRi, Clearfil Majesty Esthetic) and 3 indirect composite resins (Gradia, Estenia, Signum) were selected. The materials were incubated in unstimulated whole saliva for 1 day. The biofilms grown were collected and their bacterial cells counted. In parallel, the composite resin surface morphology was analyzed with atomic force microscopy. Both bacterial cell count and surface topography parameters were subjected to statistical analysis (α=.05). Indirect composite resins showed significantly lower levels than direct composite resins for bacterial cell adhesion, (Pcomposite resins (P>.05). However, within the indirect composite resins a significantly lower level was found for Gradia than Estenia or Signum (Pcomposite resin roughness and bacterial adhesion when the second and particularly the third-order statistical moments of the composite resin height distributions were considered. Indirect dental restorative composite resins were found to be less prone to biofilm adhesion than direct composite resins. A correlation of bacterial adhesion to surface morphology exists that is described by kurtosis; thus, advanced data analysis is required to discover possible insights into the biologic effects of morphology. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  20. Understanding dental CAD/CAM for restorations--the digital workflow from a mechanical engineering viewpoint.

    Science.gov (United States)

    Tapie, L; Lebon, N; Mawussi, B; Fron Chabouis, H; Duret, F; Attal, J-P

    2015-01-01

    As digital technology infiltrates every area of daily life, including the field of medicine, so it is increasingly being introduced into dental practice. Apart from chairside practice, computer-aided design/computer-aided manufacturing (CAD/CAM) solutions are available for creating inlays, crowns, fixed partial dentures (FPDs), implant abutments, and other dental prostheses. CAD/CAM dental solutions can be considered a chain of digital devices and software for the almost automatic design and creation of dental restorations. However, dentists who want to use the technology often do not have the time or knowledge to understand it. A basic knowledge of the CAD/CAM digital workflow for dental restorations can help dentists to grasp the technology and purchase a CAM/CAM system that meets the needs of their office. This article provides a computer-science and mechanical-engineering approach to the CAD/CAM digital workflow to help dentists understand the technology.

  1. Systematic approach to preparing ceramic-glass composites with high translucency for dental restorations.

    Science.gov (United States)

    Yoshimura, Humberto N; Chimanski, Afonso; Cesar, Paulo F

    2015-10-01

    Ceramic composites are promising materials for dental restorations. However, it is difficult to prepare highly translucent composites due to the light scattering that occurs in multiphase ceramics. The objective of this work was to verify the effectiveness of a systematic approach in designing specific glass compositions with target properties in order to prepare glass infiltrated ceramic composites with high translucency. First it was necessary to calculate from literature data the viscosity of glass at the infiltration temperature using the SciGlass software. Then, a glass composition was designed for targeted viscosity and refractive index. The glass of the system SiO2-B2O3-Al2O3-La2O3-TiO2 prepared by melting the oxide raw materials was spontaneously infiltrated into porous alumina preforms at 1200°C. The optical properties were evaluated using a refractometer and a spectrophotometer. The absorption and scattering coefficients were calculated using the Kubelka-Munk model. The light transmittance of prepared composite was significantly higher than a commercial ceramic-glass composite, due to the matching of glass and preform refractive indexes which decreased the scattering, and also to the decrease in absorption coefficient. The proposed systematic approach was efficient for development of glass infiltrated ceramic composites with high translucency, which benefits include the better aesthetic performance of the final prosthesis. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  2. How dentists diagnose and treat defective restorations: evidence from the dental practice-based research network

    DEFF Research Database (Denmark)

    Gordan, Valeria V; Garvan, Cynthia W; Richman, Joshua S

    2009-01-01

    , Norway and Sweden. METHODS: A questionnaire was sent to all DPBRN practitioner-investigators who reported doing some restorative dentistry (n = 901). Questions included clinical case scenarios that used text and clinical photographs of defective restorations. Dentists were asked what type of treatment......OBJECTIVES: To (1) identify and quantify the types of treatment that dentists use to manage defective dental restorations and (2) identify characteristics that are associated with these dentists' decisions to replace existing restorations. The Dental Practice-Based Research Network (DPBRN) consists...... of dentists in outpatient practices from five regions: AL/MS: Alabama/Mississippi; FL/GA: Florida/Georgia; MN: dentists employed by HealthPartners and private practitioners in Minnesota; PDA: Permanente Dental Associates in cooperation with Kaiser Permanente's Center for Health Research and SK: Denmark...

  3. Mechanical properties of dental restorative materials: relative contribution of laboratory tests Propriedades mecânicas dos materiais dentários restauradores: contribuição relativa dos ensaios laboratoriais

    Directory of Open Access Journals (Sweden)

    Linda Wang

    2003-09-01

    Full Text Available A wide variety of dental products that are launched on the market becomes the correct selection of these materials a difficult task. Although the mechanical properties do not necessarily represent their actual clinical performance, they are used to guide the effects of changes in their composition or processing on these properties. Also, these tests might help somehow the clinician to choose once comparisons between former formulations and new ones, as well as, with the leading brand, are highlighted by manufactures. This paper presents a review of the most important laboratory tests. In this manner, the knowledge of these tests will provide a critical opinion related to the properties of different dental materials.Uma grande variedade de produtos odontológicos que são lançados no mercado faz da seleção do material uma difícil tarefa. Apesar das propriedades mecânicas não representarem necessariamente o seu real desempenho clínico, os testes são utilizados para orientar os efeitos das alterações das composições do material ou a evolução das suas propriedades. Além disso, estas propriedades podem ajudar o clínico de alguma forma na seleção correta, uma vez que a comparação entre as formulações anteriores e as mais recentes, assim como as líderes de mercado são mais destacadas pelos fabricantes. Este artigo apresenta uma revisão dos testes laboratoriais mais importantes. Desta forma, o conhecimento destes ensaios fornecerá uma opinião crítica relacionada às propriedades dos diferentes materiais dentários.

  4. 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.

  5. OSL and TL retrospective dosimetry with a fluorapatite glass-ceramic used for dental restorations

    International Nuclear Information System (INIS)

    Ekendahl, Daniela; Judas, Libor; Sukupova, Lucie

    2013-01-01

    Optically Stimulated Luminescence (OSL) and Thermoluminescence (TL) properties of a fluorapatite glass-ceramic have been investigated, with a view to developing a dose assessment technique for medical triage following unplanned exposures of individuals to ionizing radiation. The ceramic is an innovative material used in dental prostheses and restorations. It is strongly sensitive to radiation and the intensity of both the OSL and TL signals are proportional to the absorbed radiation dose. We focused on the optimization of the measuring procedure and investigated characteristics such as reproducibility, fading, minimum detectable dose (MDD), dose response and photon energy response of TL and OSL signals. The dental ceramic exhibited very good reproducibility (<5% at 2σ level) when measured and a linear dose response for a wide range of doses (50 mGy–20 Gy). The MDD values for the samples investigated were ∼5 mGy. The material is not tissue equivalent and the OSL and TL signals are strongly dependent on incident photon energy. Both the luminescence signals exhibited significant fading during the first few hours after irradiation. Its rate was dependent on the parameters of measurement. The results indicate that the material can be used for the purposes of accident dosimetry, however, the fading and photon energy response have to be properly corrected for a reliable dose assessment. - Highlights: ► A dental ceramic was considered as a retrospective and accident dosimeter. ► Dosimetry application was investigated using OSL and TL. ► TL and OSL signals are proportional to absorbed radiation dose. ► Accuracy is dependent on correction of fading and photon energy response

  6. Efficient digitalization method for dental restorations using micro-CT data.

    Science.gov (United States)

    Kim, Changhwan; Baek, Seung Hoon; Lee, Taewon; Go, Jonggun; Kim, Sun Young; Cho, Seungryong

    2017-03-15

    The objective of this study was to demonstrate the feasibility of using micro-CT scan of dental impressions for fabricating dental restorations and to compare the dimensional accuracy of dental models generated from various methods. The key idea of the proposed protocol is that dental impression of patients can be accurately digitized by micro-CT scan and that one can make digital cast model from micro-CT data directly. As air regions of the micro-CT scan data of dental impression are equivalent to the real teeth and surrounding structures, one can segment the air regions and fabricate digital cast model in the STL format out of them. The proposed method was validated by a phantom study using a typodont with prepared teeth. Actual measurement and deviation map analysis were performed after acquiring digital cast models for each restoration methods. Comparisons of the milled restorations were also performed by placing them on the prepared teeth of typodont. The results demonstrated that an efficient fabrication of precise dental restoration is achievable by use of the proposed method.

  7. Efficient digitalization method for dental restorations using micro-CT data

    Science.gov (United States)

    Kim, Changhwan; Baek, Seung Hoon; Lee, Taewon; Go, Jonggun; Kim, Sun Young; Cho, Seungryong

    2017-03-01

    The objective of this study was to demonstrate the feasibility of using micro-CT scan of dental impressions for fabricating dental restorations and to compare the dimensional accuracy of dental models generated from various methods. The key idea of the proposed protocol is that dental impression of patients can be accurately digitized by micro-CT scan and that one can make digital cast model from micro-CT data directly. As air regions of the micro-CT scan data of dental impression are equivalent to the real teeth and surrounding structures, one can segment the air regions and fabricate digital cast model in the STL format out of them. The proposed method was validated by a phantom study using a typodont with prepared teeth. Actual measurement and deviation map analysis were performed after acquiring digital cast models for each restoration methods. Comparisons of the milled restorations were also performed by placing them on the prepared teeth of typodont. The results demonstrated that an efficient fabrication of precise dental restoration is achievable by use of the proposed method.

  8. In vivo Evaluation of Enamel Dental Restoration Interface by Optical Coherence Tomography

    International Nuclear Information System (INIS)

    Mota, Claudia C. B. O.; Gomes, Anderson S. L.; Kashyap, Hannah U. K. S.; Kyotoku, Bernardo B. C.

    2009-01-01

    In this work, we report in vivo application of Optical Coherence Tomography (OCT) to assess dental restorations in humans. After approval by the Ethical Committee in Humans Research of the Federal University of Pernambuco, thirty patients with resin composite restorations performed in anterior teeth were selected. The patients were clinically evaluated, and OCT was performed. Images were obtained using OCT operating in the spectral domain, with a 840 nm super luminescent diode light source (spectral width of 50 nm, fiber output power 25mW and a measured spatial resolution of 10 μm). The image acquisition time was less than one second. The results were analyzed with respect to the integrity and marginal adaptation of the restoration. Using appropriate software, the lesion region can be exactly located and a new restoration procedure can be carried out. We have shown that OCT is more than adequate in clinical practice to assess dental restorations. (Author)

  9. Investigation of contact allergy to dental materials by patch testing

    Directory of Open Access Journals (Sweden)

    Reena Rai

    2014-01-01

    Full Text Available Background: Dental products are widely used by patients and dental personnel alike and may cause problems for both. Dental materials could cause contact allergy with varying manifestations such as burning, pain, stomatitis, cheilitis, ulcers, lichenoid reactions localized to the oral mucosa in patients, and hand dermatitis in dental personnel. Patch testing with the dental series comprising commonly used materials can be used to detect contact allergies to dental materials. Aim: This study aimed to identify contact allergy among patients who have oral mucosal lesions after dental treatment and among dental personnel who came in contact with these materials. Materials and Methods: Twenty patients who had undergone dental procedures with symptoms of oral lichen planus, oral stomatitis, burning mouth, and recurrent aphthosis, were included in the study. Dental personnel with history of hand dermatitis were also included in the study. Patch testing was performed using Chemotechnique Dental Series and results interpreted as recommended by the International Contact Dermatitis Research Group (ICDRG. Results: Out of 13 patients who had undergone dental treatment/with oral symptoms, six patients with stomatitis, lichenoid lesions, and oral ulcers showed positive patch tests to a variety of dental materials, seven patients with ulcers had negative patch tests, seven dental personnel with hand dermatitis showed multiple allergies to various dental materials, and most had multiple positivities. Conclusion: The patch test is a useful, simple, noninvasive method to detect contact allergies among patients and among dental personnel dealing with these products. Long term studies are necessary to establish the relevance of these positive patch tests by eliminating the allergic substances, identifying clinical improvement, and substituting with nonallergenic materials.

  10. Dimensional changes of alginate dental impression materials.

    Science.gov (United States)

    Nallamuthu, N; Braden, M; Patel, M P

    2006-12-01

    The weight loss and corresponding dimensional changes of two dental alginate impression materials have been studied. The weight loss kinetics indicate this to be a diffusion controlled process, but with a boundary condition at the surface of the concentration decreasing exponentially with time. This is in marked contrast to most desorption processes, where the surface concentration becomes instantaneously zero. The appropriate theory has been developed for an exponential boundary condition, and its predictions compared with experimental data; the agreement was satisfactory. The diffusion coefficients for two thicknesses of the same material were not identical as predicted by theory; the possible reasons for this are discussed.

  11. Effect of dental restoration with epoxy and bioceramic paste on periodontal tissue damage

    Institute of Scientific and Technical Information of China (English)

    Nan-Lin Meng

    2017-01-01

    Objective:To study the effect of dental restoration with epoxy and bioceramic paste on periodontal tissue damage.Methods: Patients with pulpal and periapical diseases who received root canal therapy in our hospital between May 2013 and October 2016 were retrospectively analyzed, and according to the different root canal filling materials they used, they were divided into epoxy group and bioceramic group who used epoxy paste and bioceramic paste as root canal filling materials respectively. Before and after treatment, gingival crevicular fluid was collected respectively to determine the levels of inflammatory factors, oxidative stress products, cell apoptosis molecules and protease-related molecules.Results: 2 weeks after treatment, IL-1β, IL-6, CRP, ROS, MDA, AOPP, Bcl-2, Bax, Cyt-C, caspase-3, Smac, EMMPRIN, MMP-1, MMP-2, TIMP-1 and TIMP-2 levels in gingival crevicular fluid of epoxy group were not significantly different from those before treatment; IL-1β, IL-6, CRP, ROS, MDA, AOPP, Bax, Cyt-C, caspase-3, Smac, EMMPRIN, MMP-1 and MMP-2 levels in gingival crevicular fluid of bioceramic group were significantly higher than those before treatment while Bcl-2, TIMP-1 and TIMP-2 levels were significantly lower than those before treatment; IL-1β, IL-6, CRP, ROS, MDA, AOPP, Bcl-2, Bax, Cyt-C, caspase-3, Smac, EMMPRIN, MMP-1, MMP-2, TIMP-1 and TIMP-2 levels in gingival crevicular fluid were significantly different between two groups of patients after treatment.Conclusion:Epoxy paste for dental restoration causes less damage to periodontal tissue than bioceramic paste.

  12. Effect of dental restoration with epoxy and bioceramic paste on periodontal tissue damage

    Directory of Open Access Journals (Sweden)

    Nan-Lin Meng

    2017-05-01

    Full Text Available Objective: To study the effect of dental restoration with epoxy and bioceramic paste on periodontal tissue damage. Methods: Patients with pulpal and periapical diseases who received root canal therapy in our hospital between May 2013 and October 2016 were retrospectively analyzed, and according to the different root canal filling materials they used, they were divided into epoxy group and bioceramic group who used epoxy paste and bioceramic paste as root canal filling materials respectively. Before and after treatment, gingival crevicular fluid was collected respectively to determine the levels of inflammatory factors, oxidative stress products, cell apoptosis molecules and protease-related molecules. Results: 2 weeks after treatment, IL-1β, IL-6, CRP, ROS, MDA, AOPP, Bcl-2, Bax, Cyt-C, caspase-3, Smac, EMMPRIN, MMP-1, MMP-2, TIMP-1 and TIMP-2 levels in gingival crevicular fluid of epoxy group were not significantly different from those before treatment; IL-1β, IL-6, CRP, ROS, MDA, AOPP, Bax, Cyt-C, caspase-3, Smac, EMMPRIN, MMP-1 and MMP-2 levels in gingival crevicular fluid of bioceramic group were significantly higher than those before treatment while Bcl-2, TIMP-1 and TIMP-2 levels were significantly lower than those before treatment; IL-1β, IL-6, CRP, ROS, MDA, AOPP, Bcl-2, Bax, Cyt-C, caspase-3, Smac, EMMPRIN, MMP-1, MMP-2, TIMP-1 and TIMP-2 levels in gingival crevicular fluid were significantly different between two groups of patients after treatment. Conclusion: Epoxy paste for dental restoration causes less damage to periodontal tissue than bioceramic paste.

  13. Investigations of step-growth thiol-ene polymerizations for novel dental restoratives.

    Science.gov (United States)

    Lu, Hui; Carioscia, Jacquelyn A; Stansbury, Jeffery W; Bowman, Christopher N

    2005-12-01

    The goal of this work was to investigate the feasibility of formulating novel dental restorative materials that utilize a step-growth thiol-ene photopolymerization. Particularly, we are aiming to significantly reduce the polymerization shrinkage and shrinkage stress while retaining adequate physical properties as compared to current dimethacrylatre-based systems. The thiol-ene system is composed of a 4:3 molar mixture of triallyl-1,3,5-triazine-2,4,6-trione (TATATO) and pentaerythritol tetramercaptopropionate (PETMP). The simultaneous measurement of shrinkage stress and functional group conversion was performed. Solvent extraction of unreacted monomers and dynamic mechanical analysis on the polymer networks that were formed were also studied. Flexural strength was measured for both filled and unfilled PETMP/TATATO and Bis-GMA/TEGDMA systems. Photopolymerization of PETMP/TATATO occurs at a much higher rate, with the maximum polymerization rate six times faster, than Bis-GMA/TEGDMA cured under the identical conditions. The results from the simultaneous measurement of shrinkage stress and conversion showed that the onset of shrinkage stress coincides with the delayed gel point conversion, which is predicted to be 41% for the 3:4 stoichiometric PETMP/TATATO resin composition. The maximum shrinkage stress developed for PETMP/TATATO was about 0.4 MPa, which was only approximately 14% of the maximum shrinkage stress of the Bis-GMA/TEGDMA system. Adequate flexural strength and flexural modulus values were obtained for both filled and unfilled PETMP/TATATO systems. The dramatically reduced shrinkage stress, increased polymerization rate, significance increased functional group conversion, and decreased leachable species are all benefits for the use-of thiol-ene systems as potential dental restorative materials.

  14. Nano materials for Medical and Dental Applications

    International Nuclear Information System (INIS)

    Yub Kwon, T.; Oh, D.S.; Narayanan, R.

    2015-01-01

    Welcome to this special issue. Nano science and nano technology concepts are applicable across all fields of science and a more widespread application of nano materials and nano technologies is imminent or already occurring in many areas, including health care. Today is scientists take those cutting-edge technologies and concepts and apply them to medicine and dentistry. They are finding a wide variety of ways to make medical and dental materials at the nano scale to take advantage of their enhanced physical and biological properties.The purpose of this special issue is to publish high-quality research papers as well as review articles addressing recent advances in the field of nano materials for medical and dental applications. A particular interest is given to papers exploring or discussing nano materials and nano technologies related to delivery system, bonding substitutes, and surface modification techniques applicable in these areas. For this special issue, several investigators were invited to contribute original research findings that can stimulate continuing efforts to understand the cutting-edge applications of nano materials in medicine and dentistry.

  15. A comparative evaluation of four restorative materials to support undermined occlusal enamel of permanent teeth

    Directory of Open Access Journals (Sweden)

    Prabhakar A

    2006-09-01

    Full Text Available The purpose of this study was to test the support to undermined occlusal enamel provided by posterior restorative composite (FiltekTM P60, 3M Dental products USA, polyacid modified resin composite (F2000 compomer, 3M Dental products, USA., radiopaque silver alloy-glass ionomer cement (Miracle Mix. GC Corp, Tokyo, Japan and Glass Ionomer cement (Fuji IX GP. To test each material, 20 human permanent mandibular third molars were selected. The lingual cusps were removed and the dentin supporting the facial cusps was cut away, leaving a shell of enamel. Each group of prepared teeth was restored using the materials according to the manufacturer′s instructions. All the specimens were thermocycled (250 cycles, 6°C- 60°C, dwell time 30 seconds and then mounted on an acrylic base. Specimens were loaded evenly across the cusp tips at a crosshead speed of 5 mm /minute in Hounsfield universal testing machine until fracture occurred. Data obtained was analyzed using analysis of variance and Studentized- Newman- Keul′s range test. No significant differences were detected in the support provided by P-60, F 2000, Miracle Mix or Fuji IX GP groups. The support provided to undermined occlusal enamel by these materials was intermediate between no support and that provided by sound dentin. Without further development in dental material technology and evidence of its efficacy, restorative materials should not be relied upon to support undermined occlusal enamel to a level comparable to that provided by sound dentin.

  16. Mechanical fatigue degradation of ceramics versus resin composites for dental restorations.

    Science.gov (United States)

    Belli, Renan; Geinzer, Eva; Muschweck, Anna; Petschelt, Anselm; Lohbauer, Ulrich

    2014-04-01

    For posterior partial restorations an overlap of indication exists where either ceramic or resin-based composite materials can be successfully applied. The aim of this study was to compare the fatigue resistance of modern dental ceramic materials versus dental resin composites in order to address such conflicts. Bar specimens of five ceramic materials and resin composites were produced according to ISO 4049 and stored for 14 days in distilled water at 37°C. The following ceramic materials were selected for testing: a high-strength zirconium dioxide (e.max ZirCAD, Ivoclar), a machinable lithium disilicate (e.max CAD, Ivoclar), a pressable lithium disilicate ceramic (e-max Press, Ivoclar), a fluorapatite-based glass-ceramic (e.max Ceram, Ivoclar), and a machinable color-graded feldspathic porcelain (Trilux Forte, Vita). The composite materials selected were: an indirect machinable composite (Lava Ultimate, 3M ESPE) and four direct composites with varying filler nature (Clearfil Majesty Posterior, Kuraray; GrandioSO, Voco; Tetric EvoCeram, Ivoclar-Vivadent; and CeramX Duo, Dentsply). Fifteen specimens were tested in water for initial strength (σin) in 4-point bending. Using the same test set-up, the residual flexural fatigue strength (σff) was determined using the staircase approach after 10(4) cycles at 0.5 Hz (n=25). Weibull parameters σ0 and m were calculated for the σin specimens, whereas the σff and strength loss in percentage were obtained from the fatigue experiment. The zirconium oxide ceramic showed the highest σin and σff (768 and 440 MPa, respectively). Although both lithium disilicate ceramics were similar in the static test, the pressable version showed a significantly higher fatigue resistance after cyclic loading. Both the fluorapatite-based and the feldspathic porcelain showed equivalent initial and cyclic fatigue properties. From the composites, the highest filled direct material Clearfil Majesty Posterior showed superior fatigue performance

  17. Understanding dental CAD/CAM for restorations--accuracy from a mechanical engineering viewpoint.

    Science.gov (United States)

    Tapie, Laurent; Lebon, Nicolas; Mawussi, Bernardin; Fron-Chabouis, Hélène; Duret, Francois; Attal, Jean-Pierre

    2015-01-01

    As is the case in the field of medicine, as well as in most areas of daily life, digital technology is increasingly being introduced into dental practice. Computer-aided design/ computer-aided manufacturing (CAD/CAM) solutions are available not only for chairside practice but also for creating inlays, crowns, fixed partial dentures (FPDs), implant abutments, and other dental prostheses. CAD/CAM dental practice can be considered as the handling of devices and software processing for the almost automatic design and creation of dental restorations. However, dentists who want to use dental CAD/CAM systems often do not have enough information to understand the variations offered by such technology practice. Knowledge of the random and systematic errors in accuracy with CAD/CAM systems can help to achieve successful restorations with this technology, and help with the purchasing of a CAD/CAM system that meets the clinical needs of restoration. This article provides a mechanical engineering viewpoint of the accuracy of CAD/ CAM systems, to help dentists understand the impact of this technology on restoration accuracy.

  18. Future perspectives of resin-based dental materials.

    Science.gov (United States)

    Jandt, Klaus D; Sigusch, Bernd W

    2009-08-01

    This concise review and outlook paper gives a view of selected potential future developments in the area of resin-based biomaterials with an emphasis on dental composites. A selection of key publications (1 book, 35 scientific original publications and 1 website source) covering the areas nanotechnology, antimicrobial materials, stimuli responsive materials, self-repairing materials and materials for tissue engineering with direct or indirect relations and/or implications to resin-based dental materials is critically reviewed and discussed. Connections between these fields and their potential for resin-based dental materials are highlighted and put in perspective. The need to improve shrinkage properties and wear resistance is obvious for dental composites, and a vast number of attempts have been made to accomplish these aims. Future resin-based materials may be further improved in this respect if, for example nanotechnology is applied. Dental composites may, however, reach a completely new quality by utilizing new trends from materials science, such as introducing nanostructures, antimicrobial properties, stimuli responsive capabilities, the ability to promote tissue regeneration or repair of dental tissues if the composites were able to repair themselves. This paper shows selected potential future developments in the area of resin-based dental materials, gives basic and industrial researchers in dental materials science, and dental practitioners a glance into the potential future of these materials, and should stimulate discussion about needs and future developments in the area.

  19. Fifty years of Brazilian Dental Materials Group: scientific contributions of dental materials field evaluated by systematic review

    Science.gov (United States)

    ROSA, Wellington Luiz de Oliveira; SILVA, Tiago Machado; LIMA, Giana da Silveira; SILVA, Adriana Fernandes; PIVA, Evandro

    2016-01-01

    ABSTRACT Objective A systematic review was conducted to analyze Brazilian scientific and technological production related to the dental materials field over the past 50 years. Material and Methods This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (Prisma) statement. Searches were performed until December 2014 in six databases: MedLine (PubMed), Scopus, LILACS, IBECS, BBO, and the Cochrane Library. Additionally, the Brazilian patent database (INPI - Instituto Nacional de Propriedade Industrial) was screened in order to get an overview of Brazilian technological development in the dental materials field. Two reviewers independently analyzed the documents. Only studies and patents related to dental materials were included in this review. Data regarding the material category, dental specialty, number of documents and patents, filiation countries, and the number of citations were tabulated and analyzed in Microsoft Office Excel (Microsoft Corporation, Redmond, Washington, United States). Results A total of 115,806 studies and 53 patents were related to dental materials and were included in this review. Brazil had 8% affiliation in studies related to dental materials, and the majority of the papers published were related to dental implants (1,137 papers), synthetic resins (681 papers), dental cements (440 papers), dental alloys (392 papers) and dental adhesives (361 papers). The Brazilian technological development with patented dental materials was smaller than the scientific production. The most patented type of material was dental alloys (11 patents), followed by dental implants (8 patents) and composite resins (7 patents). Conclusions Dental materials science has had a substantial number of records, demonstrating an important presence in scientific and technological development of dentistry. In addition, it is important to approximate the relationship between academia and industry to expand the technological development in

  20. Mechanical characterization of materials for dental applications

    International Nuclear Information System (INIS)

    Pajares, A.; Miranda, P.; Guiberteau, F.; Cumbrera, F. I.

    2001-01-01

    An study of the damage induced in dental materials and model multilayer systems by masticatory contact stresses, simulated by hertz ian indentation test, have been performed. In particular, the nature of induced damage has been identified, and quantified from stress-strain curves and critical loads for yielding or crack initiation. For multilayer systems, test have been numerically simulated using finite element techniques (FEM). FEM simulations complement indentation test, allowing to justify the observed fracture modes from calculated stress fields. Practical implications can be derived from our results, relevant to the design of multilayer structures tolerant to contact damage. (Author) 34 refs

  1. Zirconia toughened mica glass ceramics for dental restorations.

    Science.gov (United States)

    Gali, Sivaranjani; K, Ravikumar; Murthy, B V S; Basu, Bikramjit

    2018-03-01

    The objective of the present study is to understand the role of yttria stabilized zirconia (YSZ) in achieving the desired spectrum of clinically relevant mechanical properties (hardness, elastic modulus, fracture toughness and brittleness index) and chemical solubility of mica glass ceramics. The glass-zirconia mixtures with varying amounts of YSZ (0, 5, 10, 15 and 20wt.%) were ball milled, compacted and sintered to obtain pellets of glass ceramic-YSZ composites. Phase analysis was carried out using X-ray diffraction and microstructural characterization with SEM revealed the crystal morphology of the composites. Mechanical properties such as Vickers hardness, elastic modulus, indentation fracture toughness and chemical solubility were assessed. Phase analysis of sintered pellets of glass ceramic-YSZ composites revealed the characteristic peaks of fluorophlogopite (FPP) and tetragonal zirconia. Microstructural investigation showed plate and lath-like interlocking mica crystals with embedded zirconia. Vickers hardness of 9.2GPa, elastic modulus of 125GPa, indentation toughness of 3.6MPa·m 1/2 , and chemical solubility of 30μg/cm 2 (well below the permissible limit) were recorded with mica glass ceramics containing 20wt.% YSZ. An increase in hardness and toughness of the glass ceramic-YSZ composites with no compromise on their brittleness index and chemical solubility has been observed. Such spectrum of properties can be utilised for developing a machinable ceramic for low stress bearing inlays, onlays and veneers. Copyright © 2018 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  2. Fifty years of Brazilian Dental Materials Group: scientific contributions of dental materials field evaluated by systematic review.

    Science.gov (United States)

    Rosa, Wellington Luiz de Oliveira; Silva, Tiago Machado; Lima, Giana da Silveira; Silva, Adriana Fernandes; Piva, Evandro

    2016-01-01

    A systematic review was conducted to analyze Brazilian scientific and technological production related to the dental materials field over the past 50 years. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (Prisma) statement. Searches were performed until December 2014 in six databases: MedLine (PubMed), Scopus, LILACS, IBECS, BBO, and the Cochrane Library. Additionally, the Brazilian patent database (INPI - Instituto Nacional de Propriedade Industrial) was screened in order to get an overview of Brazilian technological development in the dental materials field. Two reviewers independently analyzed the documents. Only studies and patents related to dental materials were included in this review. Data regarding the material category, dental specialty, number of documents and patents, filiation countries, and the number of citations were tabulated and analyzed in Microsoft Office Excel (Microsoft Corporation, Redmond, Washington, United States). A total of 115,806 studies and 53 patents were related to dental materials and were included in this review. Brazil had 8% affiliation in studies related to dental materials, and the majority of the papers published were related to dental implants (1,137 papers), synthetic resins (681 papers), dental cements (440 papers), dental alloys (392 papers) and dental adhesives (361 papers). The Brazilian technological development with patented dental materials was smaller than the scientific production. The most patented type of material was dental alloys (11 patents), followed by dental implants (8 patents) and composite resins (7 patents). Dental materials science has had a substantial number of records, demonstrating an important presence in scientific and technological development of dentistry. In addition, it is important to approximate the relationship between academia and industry to expand the technological development in countries such as Brazil.

  3. [Clinical and microbiological study regarding surface antibacterial properties of bioactive dental materials].

    Science.gov (United States)

    Târcă, T; Bădescu, Aida; Topoliceanu, C; Lăcătuşu, St

    2010-01-01

    In the new era of dentistry the coronal restoration materials must possess "bio-active" features represented by fluor ions release, chemical adhesion and antibacterial agents. Our study aims to determine the surface antibacterial properties of glassionomer cements and compomers. The study group included 64 patients with high cariogenic risk with 80 teeth with acute and chronic dental caries affecting proximal and occlusal dental surfaces. The teeth with cariogenic lesions were restored with zinc-oxide-eugenol (n=20), glassionomer cement GC Fuji Triage (n=20), glassionomer cement modified with resins Fuji II LC (n=20), compomer Dyract (n=20). DENTOCULT SM test (Orion Diagnostica, Finland) was used for bacterial analyses. The samples from bacterial biofilm were collected from the restorated dental surfaces (study group) and intact enamel surfaces (control group). The recorded data were processed using non-parametrical statistical tests. The lowest mean value of bacterial indices was recorded for glassionomer cement Fuji Triage (0.4), and Fuji II LC (1.2), material with highest surface antibacterial properties. The highest value (1.5) was recorded for compomer Dyract. The Kruskal-Wallis test proves the significant statistical differences between the three bioactive materials. The materials with bioactive features have the ability to inhibate the growth of Streptococcus mutans in bacterial biofilm to the surfaces of coronal restoration.

  4. Clinical Effect of Dental Adhesive on Marginal Integrity in Class I And Class II Resin-Composite Restorations

    Directory of Open Access Journals (Sweden)

    Manchorova-Veleva Neshka A.

    2015-12-01

    Full Text Available BACKGROUND: Dental adhesives are believed to influence marginal adaptation and marginal discoloration when used under posterior resin-based composite restorations. Studies on the latest adhesive systems reveal that the group of the three-step etch-and-rinse adhesive (3-E&RA and the one-step self-etch adhesive (1-SEA have entirely different bonding mechanisms, as well as different bond strength and resistance to chemical, thermal and mechanical factors. STUDY OBJECTIVES: A hypothesis that a 1-SEA would result in greater enamel marginal discoloration and poorer marginal adaptation than a 3-E&RA was tested. MATERIAL AND METHODS: One hundred restorations were placed with a 1-SEA and 100 restorations with a 3-E&RA. Teeth were restored with Filtek Supreme nanofilled resin-composite and were evaluated for marginal adaptation and marginal discoloration at baseline, and 6 months, 12 months, and 36 months postoperatively. RESULTS: The statistical analysis revealed significant differences in marginal integrity between test groups. The 1-SEA resulted in greater enamel marginal discoloration and poorer marginal adaptation than the 3-E&RA at any recall time. CONCLUSIONS: Marginal adaptation and marginal discoloration depend on the type of dentin adhesive used. The restorations with Filtek Supreme and Scotchbond MP are better than the restorations with Adper Prompt L-Pop with regard to the marginal adaptation and marginal discoloration at 6-, 12- and 36-month evaluations.

  5. Genotoxicity evaluation of dental restoration nanocomposite using comet assay and chromosome aberration test

    International Nuclear Information System (INIS)

    Musa, Marahaini; Ponnuraj, Kannan Thirumulu; Mohamad, Dasmawati; Rahman, Ismail Ab

    2013-01-01

    Nanocomposite is used as a dental filling to restore the affected tooth, especially in dental caries. The dental nanocomposite (KelFil) for tooth restoration used in this study was produced by the School of Dental Sciences, Universiti Sains Malaysia, Malaysia and is incorporated with monodispersed, spherical nanosilica fillers. The aim of the study was to determine the genotoxic effect of KelFil using in vitro genotoxicity tests. The cytotoxicity and genotoxicity of KelFil was evaluated using MTT assay, comet assay and chromosome aberration tests with or without the addition of a metabolic activation system (S9 mix), using the human lung fibroblast cell line (MRC-5). Concurrent negative and positive controls were included. In the comet assay, no comet formation was found in the KelFil groups. There was a significant difference in tail moment between KelFil groups and positive control (p < 0.05). Similarly, no significant aberrations in chromosomes were noticed in KelFil groups. The mitotic indices of treatment groups and negative control were significantly different from positive controls. Hence, it can be concluded that the locally produced dental restoration nanocomposite (KelFil) is non-genotoxic under the present test conditions. (paper)

  6. Effect of whitening toothpastes on bonding of restorative materials to ...

    African Journals Online (AJOL)

    2015-03-26

    Mar 26, 2015 ... Materials and Methods: Eighty labial enamel surfaces of primary ... Introduction ... recommended further research of dental whitening agents ... and/or enamel); or mixed failure (partial cohesive failure ..... A concise review.

  7. Grinding damage assessment for CAD-CAM restorative materials.

    Science.gov (United States)

    Curran, Philippe; Cattani-Lorente, Maria; Anselm Wiskott, H W; Durual, Stéphane; Scherrer, Susanne S

    2017-03-01

    To assess surface/subsurface damage after grinding with diamond discs on five CAD-CAM restorative materials and to estimate potential losses in strength based on crack size measurements of the generated damage. The materials tested were: Lithium disilicate (LIT) glass-ceramic (e.max CAD), leucite glass-ceramic (LEU) (Empress CAD), feldspar ceramic (VM2) (Vita Mark II), feldspar ceramic-resin infiltrated (EN) (Enamic) and a composite reinforced with nano ceramics (LU) (Lava Ultimate). Specimens were cut from CAD-CAM blocs and pair-wise mirror polished for the bonded interface technique. Top surfaces were ground with diamond discs of respectively 75, 54 and 18μm. Chip damage was measured on the bonded interface using SEM. Fracture mechanics relationships were used to estimate fracture stresses based on average and maximum chip depths assuming these to represent strength limiting flaws subjected to tension and to calculate potential losses in strength compared to manufacturer's data. Grinding with a 75μm diamond disc induced on a bonded interface critical chips averaging 100μm with a potential strength loss estimated between 33% and 54% for all three glass-ceramics (LIT, LEU, VM2). The softer materials EN and LU were little damage susceptible with chips averaging respectively 26μm and 17μm with no loss in strength. Grinding with 18μm diamond discs was still quite detrimental for LIT with average chip sizes of 43μm and a potential strength loss of 42%. It is essential to understand that when grinding glass-ceramics or feldspar ceramics with diamond discs surface and subsurface damage are induced which have the potential of lowering the strength of the ceramic. Careful polishing steps should be carried out after grinding especially when dealing with glass-ceramics. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  8. In vitro Comparative Evaluation of Various Restorative Materials used for restoring Class III Cavities in Deciduous Anterior Teeth: A Clinical Study.

    Science.gov (United States)

    Priyank, Harsh; Verma, Ankita; Gupta, Komal; Chaudhary, Esha; Khandelwal, Deepak; Nihalani, Shweta

    2016-12-01

    Beauty standards in today's modernized world scenario are formed by well-aligned and well-designed bright white teeth. One of the major reasons behind patients reporting to dental clinics is pain. Caries in the anterior primary teeth forms one of the major concerns from a restorative point of view. Very few studies are quoted in literature which stresses on the follow-up of anterior restorations in primary teeth. Hence, we evaluated and compared the efficacy of composite resin and resin-modified glass ionomer cement (RGIC) for class III restorations in primary anterior teeth. The present study was conducted in the pediatric dental wing and included a total of 80 patients aged 3 to 5½ years who reported with the chief complaint of carious lesions in the primary anterior teeth. Patients having minimal of a pair of similar appearing small carious lesions on the same proximal surfaces of the deciduous maxillary incisors were included for the study. All the patients were randomly divided into two groups: One in which RGIC restoration was done and other in which composite restoration was done. Cavity preparation was done and filling of the cavity with the restorative materials was carried out. Assessment of the restorations was done at 4, 8, and 12 months time following criteria given by Ryge et al. All the results were analyzed by Statistical Package for the Social Sciences (SPSS) software. Mann-Whitney test and one-way analysis of variance (ANOVA) were used to evaluate the level of significance; p value less than 0.05 was considered as significant. For composite and RGIC restorations, the mean score for anatomic shape was 1.21 and 1.10 respectively. While comparing the clinical parameters, nonsignificant results were obtained between composite and RGIC restorative materials at 4-, 8-, and 12-month interval. On comparing the clinical parameters for individual restorative materials at different time intervals, statistically significant results were obtained only for

  9. Utilizing optical coherence tomography for CAD/CAM of indirect dental restorations

    Science.gov (United States)

    Chityala, Ravishankar; Vidal, Carola; Jones, Robert

    Optical Coherence Tomography (OCT) has seen broad application in dentistry including early carious lesion detection and imaging defects in resin composite restorations. This study investigates expanding the clinical usefulness by investigating methods to use OCT for obtaining three-dimensional (3D) digital impressions, which can be integrated to CAD/CAM manufacturing of indirect restorations. 3D surface topography `before' and `after' a cavity preparation was acquired by an intraoral cross polarization swept source OCT (CP-OCT) system with a Micro-Electro-Mechanical System (MEMS) scanning mirror. Image registration and segmentation methods were used to digitally construct a replacement restoration that modeled the original surface morphology of a hydroxyapatite sample. After high resolution additive manufacturing (e.g. polymer 3D printing) of the replacement restoration, micro-CT imaging was performed to examine the marginal adaptation. This study establishes the protocol for further investigation of integrating OCT with CAD/CAM of indirect dental restorations.

  10. Endocrine disruptors and dental materials: health implications associated with their use in Brazil

    Directory of Open Access Journals (Sweden)

    Coelho Antonio Jorge Molinário

    2002-01-01

    Full Text Available This study analyzes international historical trends in the use of different types of materials in dental practice. The author describes the chemical properties of their ingredients and the potential and observed adverse effects in patients and dental technicians resulting from clinical or occupational exposure to various metals like beryllium, used to produce metal alloys. The growing use of various products (resin cements, ionomer cements, aesthetic restorative materials, resins, endodontal cements, and others based on the compound bisphenol-A, whose chemical structure is similar to that of estrogen. Considering the demographic and contemporary work force characteristics of those involved in dental practice in the Brazil, the study highlights the possible effect of the use of these materials in both male and female patients and all age strata, as well as in health professionals with occupational exposure to products containing bisphenol-A.

  11. A comparative study of additive and subtractive manufacturing for dental restorations.

    Science.gov (United States)

    Bae, Eun-Jeong; Jeong, Il-Do; Kim, Woong-Chul; Kim, Ji-Hwan

    2017-08-01

    Digital systems have recently found widespread application in the fabrication of dental restorations. For the clinical assessment of dental restorations fabricated digitally, it is necessary to evaluate their accuracy. However, studies of the accuracy of inlay restorations fabricated with additive manufacturing are lacking. The purpose of this in vitro study was to evaluate and compare the accuracy of inlay restorations fabricated by using recently introduced additive manufacturing with the accuracy of subtractive methods. The inlay (distal occlusal cavity) shape was fabricated using 3-dimensional image (reference data) software. Specimens were fabricated using 4 different methods (each n=10, total N=40), including 2 additive manufacturing methods, stereolithography apparatus and selective laser sintering; and 2 subtractive methods, wax and zirconia milling. Fabricated specimens were scanned using a dental scanner and then compared by overlapping reference data. The results were statistically analyzed using a 1-way analysis of variance (α=.05). Additionally, the surface morphology of 1 randomly (the first of each specimen) selected specimen from each group was evaluated using a digital microscope. The results of the overlap analysis of the dental restorations indicated that the root mean square (RMS) deviation observed in the restorations fabricated using the additive manufacturing methods were significantly different from those fabricated using the subtractive methods (Padditive manufacturing methods (P=.466). Similarly, no significant differences were found between wax and zirconia, the subtractive methods (P=.986). The observed RMS values were 106 μm for stereolithography apparatus, 113 μm for selective laser sintering, 116 μm for wax, and 119 μm for zirconia. Microscopic evaluation of the surface revealed a fine linear gap between the layers of restorations fabricated using stereolithography apparatus and a grooved hole with inconsistent weak scratches

  12. Restorative treatment thresholds for interproximal primary caries based on radiographic images: findings from the Dental Practice-Based Research Network

    DEFF Research Database (Denmark)

    Gordan, Valeria V; Garvan, Cynthia W; Heft, Marc W

    2009-01-01

    with restorative intervention in lesions that have penetrated only the enamel surface. This study surveyed dentists from the Dental Practice-Based Research Network (DPBRN) who had reported doing at least some restorative dentistry (n = 901). Dentists were asked to indicate the depth at which they would restore...

  13. Competitive light absorbers in photoactive dental resin-based materials.

    Science.gov (United States)

    Hadis, Mohammed A; Shortall, Adrian C; Palin, William M

    2012-08-01

    The absorbance profile of photoinitiators prior to, during and following polymerization of light curable resin-based materials will have a significant effect on the cure and color properties of the final material. So-called "colorless" photoinitiators are used in some light-activated resin-based composite restorative materials to lessen the yellowing effect of camphoroquinone (CQ) in order to improve the esthetic quality of dental restorations. This work characterizes absorption properties of commonly used photoinitiators, an acylphosphine oxide (TPO) and CQ, and assesses their influence on material discoloration. Dimethacrylate resin formulations contained low (0.0134 mol/dm(3)), intermediate (0.0405 mol/dm(3)) or high (0.0678 mol/dm(3)) concentrations of the photoinitiators and the inhibitor, butylated hydroxytoluene (BHT) at 0, 0.1 or 0.2% by mass. Disc shaped specimens (n = 3) of each resin were polymerized for 60s using a halogen light curing unit. Dynamic measurements of photoinitiator absorption, polymer conversion and reaction temperature were performed. A spectrophotometer was used to measure the color change before and after cure. GLM three-way analysis of variance revealed significant differences (pphotoinitiator type (df = 1; F = 176.12)>% BHT (df = 2, F = 13.17). BHT concentration affected the rate of polymerization and produced lower conversion in some of the CQ-based resins. Significant differences between photoinitiator type and concentrations were seen in color (where TPO resins became yellower and camphoroquinone resins became less yellow upon irradiation). Reaction temperature, kinetics and conversion also differed significantly for both initiators (presins producing a visually perceptible color change upon polymerization, the color change was significantly less than that produced with CQ-based resins. Although some photoinitiators such as TPO may be a more esthetic alternative to CQ, they may actually cause significant color contamination when

  14. Evaluation of Survival Time of Tooth Color Dental Materials in Primary Anterior Teeth

    Directory of Open Access Journals (Sweden)

    Behjat-Al-Molook Ajami

    2013-01-01

    Full Text Available Introduction: In restorative dentistry, selecting the proper material is an important factor for clinical success. The objective of this study was clinical evaluation of survival time of three tooth color materials in primary anterior teeth. Methods: In this interventional clinical trial study, 94 deciduous anterior teeth (36 teeth in boys, 58 teeth in girls belonging to 3-5 year old children in Pediatric Department of Mashhad Faculty of Dentistry, Iran were selected. Selective dental materials included compoglass, glass-ionomer Fuji II LC, and composite resin. The data were analyzed with Kaplan–Meyer and Log rank test. Results: compoglass had the highest survival time in comparison with composite and glass-ionomer. Nine months retention rate for teeth restored with compoglass, composite resin and glass-ionomer were estimated: 95%, 21%, and 12.5%, respectively. Conclusion: Compoglass can be a suitable material for anterior primary teeth restoration

  15. Evaluation of Survival Time of Tooth Color Dental Materials in Primary Anterior Teeth

    Directory of Open Access Journals (Sweden)

    Taraneh Movahhed

    2012-09-01

    Full Text Available Introduction: In restorative dentistry, selecting the proper material is an important factor for clinical success. The objective of this study was clinical evaluation of survival time of three tooth color materials in primary anterior teeth. Methods: In this interventional clinical trial study, 94 deciduous anterior teeth (36 teeth in boys, 58 teeth in girls belonging to 3-5 year old children in Pediatric Department of Mashhad Faculty of Dentistry, Iran were selected. Selective dental materials included compoglass, glass-ionomer Fuji II LC, and composite resin. The data were analyzed with Kaplan–Meyer and Log rank test. Results: compoglass had the highest survival time in comparison with composite and glass-ionomer. Nine months retention rate for teeth restored with compoglass, composite resin and glass-ionomer were estimated: 95%, 21%, and 12.5%, respectively. Conclusion: Compoglass can be a suitable material for anterior primary teeth restoration.

  16. Esthetic modification of cast dental-ceramic restorations.

    Science.gov (United States)

    Campbell, S D

    1990-01-01

    The advantages and disadvantages of conventional opaque substructures (eg, metal ceramic restorations) used for creating esthetic complete crown restorations are reviewed, and the esthetic advantages of veneering a translucent crown (Dicor) are considered. An appropriate aluminous veneering porcelain was identified (Vitadur Veneer). This veneer porcelain was chosen to match the thermal coefficient of expansion of the cast glass-ceramic substructure. A flexural strength study was then completed and it showed no difference in the strength of the veneered and nonveneered translucent cast glass-ceramic specimens. Scanning electron microscopy revealed that the interface between the porcelain veneer and cast glass-ceramic substructure had no visible porosity and resulted in a continuous-appearing structure. Potential coping designs, as well as the clinical applications and ramifications of this modified crown, are discussed.

  17. Adhesive Bonding to Computer-aided Design/ Computer-aided Manufacturing Esthetic Dental Materials: An Overview.

    Science.gov (United States)

    Awad, Mohamed Moustafa; Alqahtani, H; Al-Mudahi, A; Murayshed, M S; Alrahlah, A; Bhandi, Shilpa H

    2017-07-01

    To review the adhesive bonding to different computer-aided design/computer-aided manufacturing (CAD/CAM) esthetic restorative materials. The use of CAD/CAM esthetic restorative materials has gained popularity in recent years. Several CAD/ CAM esthetic restorative materials are commercially available. Adhesive bonding is a major determinant of success of CAD/ CAM restorations. Review result: An account of the currently available bonding strategies are discussed with their rationale in various CAD/ CAM materials. Different surface treatment methods as well as adhesion promoters can be used to achieve reliable bonding of CAD/CAM restorative materials. Selection of bonding strategy to such material is determined based on its composition. Further evidence is required to evaluate the effect of new surface treatment methods, such as nonthermal atmospheric plasma and self-etching ceramic primer on bonding to different dental ceramics. An understanding of the currently available bonding strategies to CA/CAM materials can help the clinician to select the most indicated system for each category of materials.

  18. The use of a masticatory robot to analyze the shock absorption capacity of different restorative materials for implant prosthesis

    Directory of Open Access Journals (Sweden)

    M. Menini

    2011-01-01

    Full Text Available The aim of the present research was to measure in vitro the chewing load forces transmitted through crowns made of different prosthetic restorative materials onto the dental implant. A masticatory robot that is able to reproduce the mandibular movements and the forces exerted during mastication was used. The forces transmitted to the simulated periimplant bone during the robot mastication were analysis of variance (ANOVA was used. The zirconia and the ceramic crowns transmitted significantly greater forces (p-value < 0.0001 than the other crowns tested. Dental materials with lower elastic modulus were better able to ansorb shock from acclusal forces than more rigid materials.

  19. Marginal adaptation and CAD-CAM technology: A systematic review of restorative material and fabrication techniques.

    Science.gov (United States)

    Papadiochou, Sofia; Pissiotis, Argirios L

    2018-04-01

    The comparative assessment of computer-aided design and computer-aided manufacturing (CAD-CAM) technology and other fabrication techniques pertaining to marginal adaptation should be documented. Limited evidence exists on the effect of restorative material on the performance of a CAD-CAM system relative to marginal adaptation. The purpose of this systematic review was to investigate whether the marginal adaptation of CAD-CAM single crowns, fixed dental prostheses, and implant-retained fixed dental prostheses or their infrastructures differs from that obtained by other fabrication techniques using a similar restorative material and whether it depends on the type of restorative material. An electronic search of English-language literature published between January 1, 2000, and June 30, 2016, was conducted of the Medline/PubMed database. Of the 55 included comparative studies, 28 compared CAD-CAM technology with conventional fabrication techniques, 12 contrasted CAD-CAM technology and copy milling, 4 compared CAD-CAM milling with direct metal laser sintering (DMLS), and 22 investigated the performance of a CAD-CAM system regarding marginal adaptation in restorations/infrastructures produced with different restorative materials. Most of the CAD-CAM restorations/infrastructures were within the clinically acceptable marginal discrepancy (MD) range. The performance of a CAD-CAM system relative to marginal adaptation is influenced by the restorative material. Compared with CAD-CAM, most of the heat-pressed lithium disilicate crowns displayed equal or smaller MD values. Slip-casting crowns exhibited similar or better marginal accuracy than those fabricated with CAD-CAM. Cobalt-chromium and titanium implant infrastructures produced using a CAD-CAM system elicited smaller MD values than zirconia. The majority of cobalt-chromium restorations/infrastructures produced by DMLS displayed better marginal accuracy than those fabricated with the casting technique. Compared with copy

  20. New layer-based imaging and rapid prototyping techniques for computer-aided design and manufacture of custom dental restoration.

    Science.gov (United States)

    Lee, M-Y; Chang, C-C; Ku, Y C

    2008-01-01

    Fixed dental restoration by conventional methods greatly relies on the skill and experience of the dental technician. The quality and accuracy of the final product depends mostly on the technician's subjective judgment. In addition, the traditional manual operation involves many complex procedures, and is a time-consuming and labour-intensive job. Most importantly, no quantitative design and manufacturing information is preserved for future retrieval. In this paper, a new device for scanning the dental profile and reconstructing 3D digital information of a dental model based on a layer-based imaging technique, called abrasive computer tomography (ACT) was designed in-house and proposed for the design of custom dental restoration. The fixed partial dental restoration was then produced by rapid prototyping (RP) and computer numerical control (CNC) machining methods based on the ACT scanned digital information. A force feedback sculptor (FreeForm system, Sensible Technologies, Inc., Cambridge MA, USA), which comprises 3D Touch technology, was applied to modify the morphology and design of the fixed dental restoration. In addition, a comparison of conventional manual operation and digital manufacture using both RP and CNC machining technologies for fixed dental restoration production is presented. Finally, a digital custom fixed restoration manufacturing protocol integrating proposed layer-based dental profile scanning, computer-aided design, 3D force feedback feature modification and advanced fixed restoration manufacturing techniques is illustrated. The proposed method provides solid evidence that computer-aided design and manufacturing technologies may become a new avenue for custom-made fixed restoration design, analysis, and production in the 21st century.

  1. Mercury release from dental amalgam restorations after magnetic resonance imaging and following mobile phone use.

    Science.gov (United States)

    Mortazavi, S M J; Daiee, E; Yazdi, A; Khiabani, K; Kavousi, A; Vazirinejad, R; Behnejad, B; Ghasemi, M; Mood, M Balali

    2008-04-15

    In the 1st phase of this study, thirty patients were investigated. Five milliliter stimulated saliva was collected just before and after MRI. The magnetic flux density was 0.23 T and the duration of exposure of patients to magnetic field was 30 minutes. In the 2nd phase, fourteen female healthy University students who had not used mobile phones before the study and did not have any previous amalgam restorations were investigated. Dental amalgam restoration was performed for all 14 students. Their urine samples were collected before amalgam restoration and at days 1, 2, 3 and 4 after restoration. The mean +/- SD saliva Hg concentrations of the patients before and after MRI were 8.6 +/- 3.0 and 11.3 +/- 5.3 microg L(-1), respectively (p mobile phone. The mean +/- SE urinary Hg concentrations of the students who used mobile phones were 2.43 +/- 0.25, 2.71 +/- 0.27, 3.79 +/- 0.25, 4.8 +/- 0.27 and 4.5 +/- 0.32 microg L(-1) before the amalgam restoration and at days 1, 2, 3 and 4, respectively. Whereas the respective Hg concentrations in the controls, were 2.07 +/- 0.22, 2.34 +/- 0.30, 2.51 +/- 0.25, 2.66 +/- 0.24 and 2.76 +/- 0.32 microg L(-1). It appears that MRI and microwave radiation emitted from mobile phones significantly release mercury from dental amalgam restoration. Further research is needed to clarify whether other common sources of electromagnetic field exposure may cause alterations in dental amalgam and accelerate the release of mercury.

  2. Dosimetric evaluation of scattered and attenuated radiation due to dental restorations in head and neck radiotherapy

    Directory of Open Access Journals (Sweden)

    Mona Azizi

    2018-01-01

    Full Text Available In radiotherapy of head and neck cancer, the presence of high density materials modifies photon dose distribution near these high density materials during treatment. The aim of this study is to calculate the backscatter and attenuation effects of a healthy tooth, Amalgam, Ni-Cr alloy and Ceramco on the normal tissues before and after these materials irradiated by 6 and 15 MV photon beams, respectively. All measurements were carried out in a water phantom with dimension of 50 × 50 × 50 cm3with an ionization chamber detector. Two points before and four points after the dental sample were considered to score the photon dose. The depth dose on the central beam axis was explored in a water phantom for source to surface distance (SSD of 100 cm in a 10 × 10 cm2 field size. The percentage dose change was obtained relative to the dose in water versus depth of water, tooth, Amalgam, Ni-Cr alloy and Ceramco for the photon beams. The absolute dose (cGy was measured by prescription of 100 cGy dose in the water phantom at depth of 2.0 and 3.1 cm for 6 and 15 MV photons, respectively. At depth of 0.6 cm, the maximum percentage dose increase was observed with values of 6.99% and 9.43%for Ni-Cr and lowest percentage dose increase of 1.49% and 2.63% are related to the healthy tooth in 6 and 15 MV photon beams, respectively. The maximum absolute dose of 95.58 cGy and 93.64 cGy were observed at depth of 0.6 cm in presence of Ni-Cr alloy for 6 and 15 MV photon beams, respectively. The presence of dental restorations can cause backscattering dose during head and neck radiation therapy. Introduction of compositions and electron density of high density materials can improve the accuracy of dosimetric calculations in treatment planning systems to deliver the relevant dose to target organ and reduce the backscattering dose in healthy tissues in the surrounding of tooth.

  3. DENTAL MATERIAL BIOCOMPATIBILITY: A CROSS-SECTIONAL STUDY

    Directory of Open Access Journals (Sweden)

    Carmen SAVIN

    2017-06-01

    Full Text Available The aim of this study is to assess the knowledge of the students in the Faculty of Dental Medicine of Iasi on the biocompatibility of the dental materials used in current practice. To this end, we elaborated our own questionnaire, including 10 questions to which 92 students from the last 2 years of study answered. The questionnaire cotains assertions on the potential toxic reactions of the most frequently used dental materials. The students answered correctly to the questions related to the biocompatibility of certain dental materials, such as glass-ionomer cement and calcium hydroxide, and they recognized that allergic reactions determined by acrylic resins may occur. We also noticed the lack of knowledge referring to the irreversible modifications produced by the tooth whitening substances on the enamel and dentin, as well as to the side effects produced by dental amalgam.

  4. Effect of the video output of the dental operating microscope on anxiety levels in a pediatric population during restorative procedures

    Directory of Open Access Journals (Sweden)

    Abrar Sayed

    2016-01-01

    Full Text Available Background: Adapting a child to the alien settings of a dental operatory is a major challenge to the dentist. Fear of the unknown and preconceived notions of dental pain causes anxiety in the pediatric patient. This often leads to disruptive and uncooperative behavior in the dental operatory. Many methods of behavior management have been described, of which the Tell-Show-Do (TSD is an established and time-tested technique of behavior management. Aim: To determine if a live visual output of the dental operating microscope (DOM could be used as an adjunct to the TSD technique, to involve the child more completely in the procedure and reduce the fear of the unknown. Materials and Methods: The study was a randomized, controlled, crossover, and cross-sectional clinical trial. Data were obtained from two visits. 90 children having carious lesions on both lower first molars, in the 7-9 years age group were selected and divided randomly into two groups. Restorative procedures were performed on one tooth per visit, with visits 1 week apart. Live display of the procedure was shown to the patient using video output of the DOM displayed on a 72 inch LCD monitor, angled for best visibility of the child. Anxiety levels were evaluated using Venhams picture selection test and pulse oximetry. Statistical Analysis: Student′s t-test was used to compare the anxiety scores obtained from the two groups. Results: The results showed there was a decrease in the anxiety from the first visit to the second visit. (P = 0.05 for Group A and P = 0.003 for Group B. The patients preferred the visit in which the DOM was used. The operator reported an increased patient compliance and reduced patient movement in the visits in which the DOM was used. Conclusion: There is a reduction in anxiety from the first visit to the second visit for restorative treatment when the DOM is used.

  5. Gingival and dental parameters in the evaluation of aesthetic characteristics of fixed restorations (II

    Directory of Open Access Journals (Sweden)

    Obradović-Đuričić Kosovka

    2005-01-01

    Full Text Available This paper is a continuing evaluation of dental and facial parameters in the estimation of aesthetic characteristic of fixed restorations. First of all, attention is paid to the phenomenon describing the tooth tissue's characteristics (transiucency, opalescence, and transparency. The paper also discusses tooth color as a special occurrence, the position of the lower lip line as well as the symmetry of the smile. In addition to these fundamental objective criteria, the paper also deals with subjective criteria (tooth arrangement and position, variation in tooth form, and relative crown length, which play a part in the successful aesthetic integration of fixed restorations.

  6. Performance of dental impression materials: Benchmarking of materials and techniques by three-dimensional analysis.

    Science.gov (United States)

    Rudolph, Heike; Graf, Michael R S; Kuhn, Katharina; Rupf-Köhler, Stephanie; Eirich, Alfred; Edelmann, Cornelia; Quaas, Sebastian; Luthardt, Ralph G

    2015-01-01

    Among other factors, the precision of dental impressions is an important and determining factor for the fit of dental restorations. The aim of this study was to examine the three-dimensional (3D) precision of gypsum dies made using a range of impression techniques and materials. Ten impressions of a steel canine were fabricated for each of the 24 material-method-combinations and poured with type 4 die stone. The dies were optically digitized, aligned to the CAD model of the steel canine, and 3D differences were calculated. The results were statistically analyzed using one-way analysis of variance. Depending on material and impression technique, the mean values had a range between +10.9/-10.0 µm (SD 2.8/2.3) and +16.5/-23.5 µm (SD 11.8/18.8). Qualitative analysis using colorcoded graphs showed a characteristic location of deviations for different impression techniques. Three-dimensional analysis provided a comprehensive picture of the achievable precision. Processing aspects and impression technique were of significant influence.

  7. Impact of Atraumatic Restorative Treatment (ART) on the treatment profile in pilot government dental clinics in Tanzania.

    Science.gov (United States)

    Kikwilu, Emil Namakuka; Frencken, Jo; Mulder, Jan

    2009-06-08

    The predominant mode of treatment in government dental clinics in Tanzania has been tooth extraction because the economy could not support the conventional restorative care which depends on expensive equipment, electricity and piped water systems. Atraumatic Restorative Treatment (ART) was perceived as a suitable alternative. A 3.5-year study was designed to document the changes in the treatment profiles ascribed to the systematic introduction of ART in pilot government dental clinics. Dental practitioners who were working in 13 government dental clinics underwent a 7-day ART training. Treatment record data on teeth extracted and teeth restored by the conventional and ART approaches were collected from these clinics for the three study periods. The mean percentage of ART restorations to total treatment, ART restorations to total restorations, and total restorations to total treatments rendered were computed. Differences between variables were determined by ANOVA, t-test and Chi-square. The mean percentage of ART restorations to total treatment rendered was 0.4 (SE = 0.5) and 11.9 (SE = 1.1) during the baseline and second follow-up period respectively (ANOVA mixed model; P ART restorations to total restorations rendered at baseline and 2nd follow-up period was 8.4% and 88.9% respectively (ANOVA mixed model; P ART restorations, 96.6% willing to receive ART restoration again in future, and 94.9% willing to recommend ART treatment to their close relatives. ART introduction in pilot government dental clinics raised the number of teeth saved by restorative care. Countrywide introduction of the ART approach in Tanzania is recommended.

  8. 3D printed versus conventionally cured provisional crown and bridge dental materials.

    Science.gov (United States)

    Tahayeri, Anthony; Morgan, MaryCatherine; Fugolin, Ana P; Bompolaki, Despoina; Athirasala, Avathamsa; Pfeifer, Carmem S; Ferracane, Jack L; Bertassoni, Luiz E

    2018-02-01

    To optimize the 3D printing of a dental material for provisional crown and bridge restorations using a low-cost stereolithography 3D printer; and compare its mechanical properties against conventionally cured provisional dental materials. Samples were 3D printed (25×2×2mm) using a commercial printable resin (NextDent C&B Vertex Dental) in a FormLabs1+ stereolithography 3D printer. The printing accuracy of printed bars was determined by comparing the width, length and thickness of samples for different printer settings (printing orientation and resin color) versus the set dimensions of CAD designs. The degree of conversion of the resin was measured with FTIR, and both the elastic modulus and peak stress of 3D printed bars was determined using a 3-point being test for different printing layer thicknesses. The results were compared to those for two conventionally cured provisional materials (Integrity ® , Dentsply; and Jet ® , Lang Dental Inc.). Samples printed at 90° orientation and in a white resin color setting was chosen as the most optimal combination of printing parameters, due to the comparatively higher printing accuracy (up to 22% error), reproducibility and material usage. There was no direct correlation between printing layer thickness and elastic modulus or peak stress. 3D printed samples had comparable modulus to Jet ® , but significantly lower than Integrity ® . Peak stress for 3D printed samples was comparable to Integrity ® , and significantly higher than Jet ® . The degree of conversion of 3D printed samples also appeared higher than that of Integrity ® or Jet ® . Our results suggest that a 3D printable provisional restorative material allows for sufficient mechanical properties for intraoral use, despite the limited 3D printing accuracy of the printing system of choice. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  9. SU-F-T-426: Measurement of Dose Enhancement Due to Backscatter From Modern Dental Materials

    International Nuclear Information System (INIS)

    Hurwitz, M; Margalit, D; Williams, C; Tso, T; Lee, S; Rosen, E

    2016-01-01

    Purpose: High-density materials used in dental restoration can cause significant localized dose enhancement due to electron backscatter in head-and-neck radiotherapy, increasing the risk of mucositis. The materials used in prosthetic dentistry have evolved in the last decades from metal alloys to ceramics. We aim to determine the dose enhancement caused by backscatter from currently-used dental materials. Methods: Measurements were performed for three different dental materials: lithium disilicate (Li 2 Si 2 O 5 ), zirconium dioxide (ZrO 2 ), and gold alloy. Small thin squares (2×2×0.15 cm 3 ) of the material were fabricated, and placed into a phantom composed of tissue-equivalent material. The phantom was irradiated with a single 6 MV photon field. A thin-window parallel-plate ion chamber was used to measure the dose at varying distances from the proximal interface between the material and the plastic. Results: The dose enhancement at the interface between the high-density and tissue-equivalent materials, relative to a homogeneous phantom, was 54% for the gold alloy, 31% for ZrO 2 , and 9% for Li 2 Si 2 O 5 . This enhancement decreased rapidly with distance from the interface, falling to 11%, 5%, and 0.5%, respectively, 2 mm from the interface. Comparisons with the modeling of this effect in treatment planning systems are performed. Conclusion: While dose enhancement due to dental restoration is smaller with ceramic materials than with metal alloys, it can still be significant. A spacer of about 2–3 mm would be effective in reducing this enhancement, even for metal alloys.

  10. SU-F-T-426: Measurement of Dose Enhancement Due to Backscatter From Modern Dental Materials

    Energy Technology Data Exchange (ETDEWEB)

    Hurwitz, M; Margalit, D; Williams, C [Brigham and Women’s Hospital / Harvard Medical School, Boston, MA (United States); Tso, T; Lee, S; Rosen, E [Harvard School of Dental Medicine, Boston, MA (United States)

    2016-06-15

    Purpose: High-density materials used in dental restoration can cause significant localized dose enhancement due to electron backscatter in head-and-neck radiotherapy, increasing the risk of mucositis. The materials used in prosthetic dentistry have evolved in the last decades from metal alloys to ceramics. We aim to determine the dose enhancement caused by backscatter from currently-used dental materials. Methods: Measurements were performed for three different dental materials: lithium disilicate (Li{sub 2}Si{sub 2}O{sub 5}), zirconium dioxide (ZrO{sub 2}), and gold alloy. Small thin squares (2×2×0.15 cm{sup 3}) of the material were fabricated, and placed into a phantom composed of tissue-equivalent material. The phantom was irradiated with a single 6 MV photon field. A thin-window parallel-plate ion chamber was used to measure the dose at varying distances from the proximal interface between the material and the plastic. Results: The dose enhancement at the interface between the high-density and tissue-equivalent materials, relative to a homogeneous phantom, was 54% for the gold alloy, 31% for ZrO{sub 2}, and 9% for Li{sub 2}Si{sub 2}O{sub 5}. This enhancement decreased rapidly with distance from the interface, falling to 11%, 5%, and 0.5%, respectively, 2 mm from the interface. Comparisons with the modeling of this effect in treatment planning systems are performed. Conclusion: While dose enhancement due to dental restoration is smaller with ceramic materials than with metal alloys, it can still be significant. A spacer of about 2–3 mm would be effective in reducing this enhancement, even for metal alloys.

  11. Validation of assessment of intraoral digital photography for evaluation of dental restorations in clinical research.

    Science.gov (United States)

    Signori, Cácia; Collares, Kauê; Cumerlato, Catarina B F; Correa, Marcos B; Opdam, Niek J M; Cenci, Maximiliano S

    2018-04-01

    The aim of this study was to investigate the validity of assessment of intraoral digital photography in the evaluation of dental restorations. Intraoral photographs of anterior and posterior restorations were classified based on FDI criteria according to the need for intervention: no intervention, repair and replacement. Evaluations were performed by an experienced expert in restorative dentistry (gold standard evaluator) and 3 trained dentists (consensus). The clinical inspection was the reference standard method. The prevalence of failures was explored. Cohen's kappa statistic was used. Validity was accessed by sensitivity, specificity, likelihood ratio and predictives values. Higher prevalence of failed restorations intervention was identified by the intraoral photography (17.7%) in comparison to the clinical evaluation (14.1%). Moderate agreement in the diagnosis of total failures was shown between the methods for the gold standard evaluator (kappa = 0.51) and consensus of evaluators (kappa = 0.53). Gold standard evaluator and consensus showed substantial and moderate agreement for posterior restorations (kappa = 0.61; 0.59), and fair and moderate agreement for anterior restorations (kappa = 0.36; 0.43), respectively. The accuracy was 84.8% in the assessment by intraoral photographs. Sensitivity and specificity values of 87.5% and 89.3% were found. Under the limits of this study, the assessment of digital photography performed by intraoral camera is an indirect diagnostic method valid for the evaluation of dental restorations, mainly in posterior teeth. This method should be employed taking into account the higher detection of defects provided by the images, which are not always clinically relevant. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Evaluation of dental restorations: a comparative study between clinical and digital photographic assessments.

    Science.gov (United States)

    Moncada, G; Silva, F; Angel, P; Oliveira, O B; Fresno, M C; Cisternas, P; Fernandez, E; Estay, J; Martin, J

    2014-01-01

    The aim of this study was to compare the efficacy of a direct clinical evaluation method with an indirect digital photographic method in assessing the quality of dental restorations. Seven parameters (color, occlusal marginal adaptation, anatomy form, roughness, occlusal marginal stain, luster, and secondary caries) were assessed in 89 Class I and Class II restorations from 36 adults using the modified US Public Health Service/Ryge criteria. Standardized photographs of the same restorations were digitally processed by Adobe Photoshop software, separated into the following four groups and assessed by two calibrated examiners: Group A: The original photograph displayed at 100%, without modifications (IMG100); Group B: Formed by images enlarged at 150% (IMG150); Group C: Formed by digital photographs displayed at 100% (mIMG100), with digital modifications (levels adjustment, shadow and highlight correction, color balance, unsharp Mask); and Group D: Formed by enlarged photographs displayed at 150% with modifications (mIMG150), with the same adjustments made to Group C. Photographs were assessed on a calibrated screen (Macbook) by two calibrated clinicians, and the results were statistically analyzed using Wilcoxon tests (SSPS 11.5) at 95% CI. The photographic method produced higher reliability levels than the direct clinical method in all parameters. The evaluation of digital images is more consistent with clinical assessment when restorations present some moderate defect (Bravo) and less consistent when restorations are clinically classified as either satisfactory (Alpha) or in cases of severe defects (Charlie). The digital photographic method is a useful tool for assessing the quality of dental restorations, providing information that goes unnoticed with the visual-tactile clinical examination method. Additionally, when analyzing restorations using the Ryge modified criteria, the digital photographic method reveals a significant increase of defects compared to those

  13. Understanding the management and teaching of dental restoration repair: Systematic review and meta-analysis of surveys.

    Science.gov (United States)

    Kanzow, Philipp; Wiegand, Annette; Göstemeyer, Gerd; Schwendicke, Falk

    2018-02-01

    Repair instead of complete replacement is recommended to manage partially defective restorations. It is unclear if and why such treatment is taught at dental schools or practiced by dentists. We aimed to identify barriers and facilitators for repairs using a systematic review and meta- and qualitative analysis. Electronic databases (PubMed, CENTRAL, Embase, PsycINFO) were searched. Quantitative studies reporting on the proportion of (1) dentists stating to perform repairs, (2) dental schools teaching repairs, (3) failed restorations having been repaired were included. We also included qualitative studies on barriers/facilitators for repairs. Random-effects meta-analyses, meta-regression and a thematic analysis using the theoretical domains framework were conducted. 401 articles were assessed and 29, mainly quantitative, studies included. 7228 dentists and 276 dental schools had been surveyed, and treatment data of 30,172 restorations evaluated. The mean (95% CI) proportion of dentists stating to perform repairs was 71.5% (49.7-86.4%). 83.3% (73.6-90.0%) of dental schools taught repairs. 31.3% (26.3-36.7%) of failed restorations had been repaired. More recent studies reported significantly more dentists to repair restorations (p=0.004). Employment in public health practices and being the dentist who placed the original restoration were facilitators for repairs. Amalgam restorations were repaired less often, and financial aspects and regulations came as barriers. While most dentists state to perform repairs and the vast majority of dental schools teach repairs, the proportion of truly repaired restorations was low. A number of interventions to implement repair in dental practice can be deduced from our findings. Partially defective restorations are common in dental practice. While repairs are taught and dentists are aware of the recommendation towards repairs, the actually performed proportion of repairs seems low. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Dental Glass Ionomer Cements as Permanent Filling Materials? – Properties, Limitations and Future Trends

    Directory of Open Access Journals (Sweden)

    Ulrich Lohbauer

    2009-12-01

    Full Text Available Glass ionomer cements (GICs are clinically attractive dental materials that have certain unique properties that make them useful as restorative and luting materials. This includes adhesion to moist tooth structures and base metals, anticariogenic properties due to release of fluoride, thermal compatibility with tooth enamel, biocompatibility and low toxicity. The use of GICs in a mechanically loaded situation, however, has been hampered by their low mechanical performance. Poor mechanical properties, such as low fracture strength, toughness and wear, limit their extensive use in dentistry as a filling material in stress-bearing applications. In the posterior dental region, glass ionomer cements are mostly used as a temporary filling material. The requirement to strengthen those cements has lead to an ever increasing research effort into reinforcement or strengthening concepts.

  15. A new classification system for all-ceramic and ceramic-like restorative materials.

    Science.gov (United States)

    Gracis, Stefano; Thompson, Van P; Ferencz, Jonathan L; Silva, Nelson R F A; Bonfante, Estevam A

    2015-01-01

    Classification systems for all-ceramic materials are useful for communication and educational purposes and warrant continuous revisions and updates to incorporate new materials. This article proposes a classification system for ceramic and ceramic-like restorative materials in an attempt to systematize and include a new class of materials. This new classification system categorizes ceramic restorative materials into three families: (1) glass-matrix ceramics, (2) polycrystalline ceramics, and (3) resin-matrix ceramics. Subfamilies are described in each group along with their composition, allowing for newly developed materials to be placed into the already existing main families. The criteria used to differentiate ceramic materials are based on the phase or phases present in their chemical composition. Thus, an all-ceramic material is classified according to whether a glass-matrix phase is present (glass-matrix ceramics) or absent (polycrystalline ceramics) or whether the material contains an organic matrix highly filled with ceramic particles (resin-matrix ceramics). Also presented are the manufacturers' clinical indications for the different materials and an overview of the different fabrication methods and whether they are used as framework materials or monolithic solutions. Current developments in ceramic materials not yet available to the dental market are discussed.

  16. Local viscoelastic response of direct and indirect dental restorative composites measured by AFM.

    Science.gov (United States)

    Grattarola, Laura; Derchi, Giacomo; Diaspro, Alberto; Gambaro, Carla; Salerno, Marco

    2018-06-08

    We investigated the viscoelastic response of direct and indirect dental restorative composites by the novel technique of AM-FM atomic force microscopy. We selected four composites for direct restorations (Adonis, Optifil, EPH, CME) and three composites for indirect restorations (Gradia, Estenia, Signum). Scanning electron microscopy with micro-analysis was also used to support the results. The mean storage modulus of all composites was in the range of 10.2-15.2 GPa. EPH was the stiffest (pcomposites but Adonis and Estenia), while no significant difference was observed between direct and indirect group (p≥0.05). For the loss tangent, Gradia had the highest value (~0.3), different (pcomposites showed higher loss tangent (pcomposites. All composites exhibited minor contrast at the edge of fillers, showing that these are pre-polymerized, as confirmed by EDS.

  17. Assessment of Heat Hazard during the Polymerization of Selected Light-Sensitive Dental Materials.

    Science.gov (United States)

    Janeczek, Maciej; Herman, Katarzyna; Fita, Katarzyna; Dudek, Krzysztof; Kowalczyk-Zając, Małgorzata; Czajczyńska-Waszkiewicz, Agnieszka; Piesiak-Pańczyszyn, Dagmara; Kosior, Piotr; Dobrzyński, Maciej

    2016-01-01

    Introduction. Polymerization of light-cured dental materials used for restoration of hard tooth tissue may lead to an increase in temperature that may have negative consequence for pulp vitality. Aim. The aim of this study was to determine maximum temperatures reached during the polymerization of selected dental materials, as well as the time that is needed for samples of sizes similar to those used in clinical practice to reach these temperatures. Materials and Methods. The study involved four composite restorative materials, one lining material and a dentine bonding agent. The polymerization was conducted with the use of a diode light-curing unit. The measurements of the external surface temperature of the samples were carried out using the Thermovision®550 thermal camera. Results. The examined materials significantly differed in terms of the maximum temperatures values they reached, as well as the time required for reaching the temperatures. A statistically significant positive correlation of the maximum temperature and the sample weight was observed. Conclusions. In clinical practice, it is crucial to bear in mind the risk of thermal damage involved in the application of light-cured materials. It can be reduced by using thin increments of composite materials.

  18. Assessment of Heat Hazard during the Polymerization of Selected Light-Sensitive Dental Materials

    Directory of Open Access Journals (Sweden)

    Maciej Janeczek

    2016-01-01

    Full Text Available Introduction. Polymerization of light-cured dental materials used for restoration of hard tooth tissue may lead to an increase in temperature that may have negative consequence for pulp vitality. Aim. The aim of this study was to determine maximum temperatures reached during the polymerization of selected dental materials, as well as the time that is needed for samples of sizes similar to those used in clinical practice to reach these temperatures. Materials and Methods. The study involved four composite restorative materials, one lining material and a dentine bonding agent. The polymerization was conducted with the use of a diode light-curing unit. The measurements of the external surface temperature of the samples were carried out using the Thermovision®550 thermal camera. Results. The examined materials significantly differed in terms of the maximum temperatures values they reached, as well as the time required for reaching the temperatures. A statistically significant positive correlation of the maximum temperature and the sample weight was observed. Conclusions. In clinical practice, it is crucial to bear in mind the risk of thermal damage involved in the application of light-cured materials. It can be reduced by using thin increments of composite materials.

  19. Review on fluoride-releasing restorative materials--fluoride release and uptake characteristics, antibacterial activity and influence on caries formation.

    Science.gov (United States)

    Wiegand, Annette; Buchalla, Wolfgang; Attin, Thomas

    2007-03-01

    The purpose of this article was to review the fluoride release and recharge capabilities, and antibacterial properties, of fluoride-releasing dental restoratives, and discuss the current status concerning the prevention or inhibition of caries development and progression. Information from original scientific full papers or reviews listed in PubMed (search term: fluoride release AND (restorative OR glass-ionomer OR compomer OR polyacid-modified composite resin OR composite OR amalgam)), published from 1980 to 2004, was included in the review. Papers dealing with endodontic or orthodontic topics were not taken into consideration. Clinical studies concerning secondary caries development were only included when performed in split-mouth design with an observation period of at least three years. Fluoride-containing dental materials show clear differences in the fluoride release and uptake characteristics. Short- and long-term fluoride releases from restoratives are related to their matrices, setting mechanisms and fluoride content and depend on several environmental conditions. Fluoride-releasing materials may act as a fluoride reservoir and may increase the fluoride level in saliva, plaque and dental hard tissues. However, clinical studies exhibited conflicting data as to whether or not these materials significantly prevent or inhibit secondary caries and affect the growth of caries-associated bacteria compared to non-fluoridated restoratives. Fluoride release and uptake characteristics depend on the matrices, fillers and fluoride content as well as on the setting mechanisms and environmental conditions of the restoratives. Fluoride-releasing materials, predominantly glass-ionomers and compomers, did show cariostatic properties and may affect bacterial metabolism under simulated cariogenic conditions in vitro. However, it is not proven by prospective clinical studies whether the incidence of secondary caries can be significantly reduced by the fluoride release of

  20. Interim restorations.

    Science.gov (United States)

    Gratton, David G; Aquilino, Steven A

    2004-04-01

    Interim restorations are a critical component of fixed prosthodontic treatment, biologically and biomechanically. Interim restoration serves an important diagnostic role as a functional and esthetic try-in and as a blueprint for the design of the definitive prosthesis. When selecting materials for any interim restoration, clinicians must consider physical properties, handling properties, patient acceptance, and material cost. Although no single material meets all the requirements and material classification alone of a given product is not a predictor of clinical performance, bis-acryl materials are typically best suited to single-unit restorations, and poly(methylmethacrylate) interim materials are generally ideal for multi-unit, complex, long-term, interim fixed prostheses. As with most dental procedures, the technique used for fabrication has a greater effect on the final result than the specific material chosen.

  1. Swept source optical coherence tomography for quantitative and qualitative assessment of dental composite restorations

    Science.gov (United States)

    Sadr, Alireza; Shimada, Yasushi; Mayoral, Juan Ricardo; Hariri, Ilnaz; Bakhsh, Turki A.; Sumi, Yasunori; Tagami, Junji

    2011-03-01

    The aim of this work was to explore the utility of swept-source optical coherence tomography (SS-OCT) for quantitative evaluation of dental composite restorations. The system (Santec, Japan) with a center wavelength of around 1300 nm and axial resolution of 12 μm was used to record data during and after placement of light-cured composites. The Fresnel phenomenon at the interfacial defects resulted in brighter areas indicating gaps as small as a few micrometers. The gap extension at the interface was quantified and compared to the observation by confocal laser scanning microscope after trimming the specimen to the same cross-section. Also, video imaging of the composite during polymerization could provide information about real-time kinetics of contraction stress and resulting gaps, distinguishing them from those gaps resulting from poor adaptation of composite to the cavity prior to polymerization. Some samples were also subjected to a high resolution microfocus X-ray computed tomography (μCT) assessment; it was found that differentiation of smaller gaps from the radiolucent bonding layer was difficult with 3D μCT. Finally, a clinical imaging example using a newly developed dental SS-OCT system with an intra-oral scanning probe (Panasonic Healthcare, Japan) is presented. SS-OCT is a unique tool for clinical assessment and laboratory research on resin-based dental restorations. Supported by GCOE at TMDU and NCGG.

  2. Color stability of esthetic restorative materials: a spectrophotometric analysis.

    Science.gov (United States)

    Poggio, Claudio; Ceci, Matteo; Beltrami, Riccardo; Mirando, Maria; Wassim, Jaffal; Colombo, Marco

    2016-12-01

    Objective: The aim of this in vitro study was to evaluate the color stability of different restorative materials (one microfilled composite, one nanofilled composite, one nanohybrid composite and one Ormocer-based composite) after exposure to different staining solutions (coffee, coca-cola and red wine). Material and methods: All materials were polymerized into silicon rings (2 mm ×6 mm ×8 mm) to obtain specimens identical in size. Thirty cylindrical specimens of each material were prepared. They were immersed in staining solutions over a 28-day test period. A colorimetric evaluation according to the CIE L*a*b* system was performed by a blind trained operator at 7, 14, 21, 28 days of the staining process. The Shapiro-Wilk test and Kruskal-Wallis ANOVA were applied to assess significant differences among restorative materials. The paired t -test was applied to test which CIE L*a*b* parameters significantly changed after immersion in staining solutions. Results: All restorative materials showed clinically perceptible color differences after immersion in coffee. L* and b* values showed the highest variability. Coca cola and red wine did not influence the color stability for all restorative materials except for Filtek Supreme XTE. Conclusions: Coffee caused a significant color change in all types of tested composite resins. Filtek Supreme XTE demonstrated alone a staining susceptibility to red wine; no other significant differences among the materials were demonstrated. Long-term exposure to some food dyes (coffee in particular) can significantly affect the color stability of modern esthetic restorative materials regardless of materials' different composition.

  3. PEEK with Reinforced Materials and Modifications for Dental Implant Applications

    Directory of Open Access Journals (Sweden)

    Fitria Rahmitasari

    2017-12-01

    Full Text Available Polyetheretherketone (PEEK is a semi-crystalline linear polycyclic thermoplastic that has been proposed as a substitute for metals in biomaterials. PEEK can also be applied to dental implant materials as a superstructure, implant abutment, or implant body. This article summarizes the current research on PEEK applications in dental implants, especially for the improvement of PEEK surface and body modifications. Although various benchmark reports on the reinforcement and surface modifications of PEEK are available, few clinical trials using PEEK for dental implant bodies have been published. Controlled clinical trials, especially for the use of PEEK in implant abutment and implant bodies, are necessary.

  4. [Evaluation method with radiographic image quality indicator for internal defects of dental casting metallic restoration].

    Science.gov (United States)

    Li, Y; Zheng, G; Lin, H

    2014-12-18

    To develop a new kind of dental radiographic image quality indicator (IQI) for internal quality of casting metallic restoration to influence on its usage life. Radiographic image quality indicator method was used to evaluate the depth of the defects region and internal quality of 127 casting metallic restoration and the accuracy was compared with that of conventional callipers method. In the 127 cases of casting metallic restoration, 9 were found the thickness less than 0.7 mm and the thinnest thickness only 0.2 mm in 26 casting metallic crowns or bridges' occlusal defects region. The data measured by image quality indicator were consistent with those measured by conventional gauging. Two metal inner crowns were found the thickness less than 0.3 mm in 56 porcelain crowns or bridges. The thickness of casting removable partial denture was more than 1.0 mm, but thinner regions were not found. It was found that in a titanium partial denture, the X-ray image of clasp was not uniform and there were internal porosity defects in the clasp. Special dental image quality indicator can solve the visual error problems caused by different observing backgrounds and estimate the depth of the defects region in the casting.

  5. Influence of immediate loading on provisional restoration in dental implant stability

    Science.gov (United States)

    Ikbal, M.; Odang, R. W.; Indrasari, M.; Dewi, R. S.

    2017-08-01

    The success of dental implant treatment is determined by the primary stability at placement. One factor that could influence this stability is occlusal loading through provisional restoration. Two types of loading protocols are usually used: immediate and delayed loading. However, some controversies remain about the influence of occlusal loading on implant stability. Therefore, the influence of immediate loading on implant stability must be studied. An animal study was conducted by placing nine dental implants in the mandibular jaw of three Macaca fascicularis. Provisional restorations with various occlusal contacts (no, light, and normal contact) were placed on the implant. The implant stability was measured using the Ostell ISQ three times: immediately (baseline) and at the first and second months after implant placement. The implant stability between implants with no and normal occlusal contact as well as light and normal occlusal contact showed significant differences (p implant placement. However, no significant increase (p > 0.05) in implant stability was seen at the baseline and the first and second months after implant placement for all occlusal contact groups. Immediate loading influenced the implant stability, and provisional restoration of implant without occlusal contact showed the highest implant stability.

  6. Fabrication of superhydrophobic coating for preventing microleakage in a dental composite restoration.

    Science.gov (United States)

    Cao, Danfeng; Zhang, Yingchao; Li, Yao; Shi, Xiaoyu; Gong, Haihuan; Feng, Dan; Guo, Xiaowei; Shi, Zuosen; Zhu, Song; Cui, Zhanchen

    2017-09-01

    Superhydrophobic coatings were successfully fabricated by photo-crosslinked polyurethane (PU) and organic fluoro group-functionalized SiO 2 nanoparticles (F-SiO 2 NPs), and were introduced for preventing microleakage in a dental composite restoration. The F-SiO 2 NPs possessed low surface energy and the PU can not only improve the mechanical stability but also promote F-SiO 2 NPs to form multiscale structure, which could facilitate the properties of the as-prepared superhydrophobic coating by synergetic effect. The morphology and properties of the resulted superhydrophobic coatings with different PU/F-SiO 2 ratios were studied using 1 H NMR spectrum, fourier transform infrared spectra, scanning electron microscopy, atomic force microscopy and UV-vis spectrophotometry. The results showed that the superhydrophobic coatings with low PU/F-SiO 2 ratio (1:3) possessed excellent hierarchical papillae structure with trapped air pockets, high contact angle (160.1°), low sliding angle (superhydrophobic property, the as-prepared superhydrophobic coatings effectively prevented water permeation in resin composite restoration evaluation. This research may provide an effective method to solve the problem of microleakage and will efficiently increase the success rate of dental composite restorations. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Environmental restoration waste materials co-disposal

    International Nuclear Information System (INIS)

    Phillips, S.J.; Alexander, R.G.; England, J.L.; Kirdendall, J.R.; Raney, E.A.; Stewart, W.E.; Dagan, E.B.; Holt, R.G.

    1993-09-01

    Co-disposal of radioactive and hazardous waste is a highly efficient and cost-saving technology. The technology used for final treatment of soil-washing size fractionization operations is being demonstrated on simulated waste. Treated material (wasterock) is used to stabilize and isolate retired underground waste disposal structures or is used to construct landfills or equivalent surface or subsurface structures. Prototype equipment is under development as well as undergoing standardized testing protocols to prequalify treated waste materials. Polymer and hydraulic cement solidification agents are currently used for geotechnical demonstration activities

  8. Biphenyl liquid crystalline epoxy resin as a low-shrinkage resin-based dental restorative nanocomposite.

    Science.gov (United States)

    Hsu, Sheng-Hao; Chen, Rung-Shu; Chang, Yuan-Ling; Chen, Min-Huey; Cheng, Kuo-Chung; Su, Wei-Fang

    2012-11-01

    Low-shrinkage resin-based photocurable liquid crystalline epoxy nanocomposite has been investigated with regard to its application as a dental restoration material. The nanocomposite consists of an organic matrix and an inorganic reinforcing filler. The organic matrix is made of liquid crystalline biphenyl epoxy resin (BP), an epoxy resin consisting of cyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (ECH), the photoinitiator 4-octylphenyl phenyliodonium hexafluoroantimonate and the photosensitizer champhorquinone. The inorganic filler is silica nanoparticles (∼70-100 nm). The nanoparticles were modified by an epoxy silane of γ-glycidoxypropyltrimethoxysilane to be compatible with the organic matrix and to chemically bond with the organic matrix after photo curing. By incorporating the BP liquid crystalline (LC) epoxy resin into conventional ECH epoxy resin, the nanocomposite has improved hardness, flexural modulus, water absorption and coefficient of thermal expansion. Although the incorporation of silica filler may dilute the reinforcing effect of crystalline BP, a high silica filler content (∼42 vol.%) was found to increase the physical and chemical properties of the nanocomposite due to the formation of unique microstructures. The microstructure of nanoparticle embedded layers was observed in the nanocomposite using scanning and transmission electron microscopy. This unique microstructure indicates that the crystalline BP and nanoparticles support each other and result in outstanding mechanical properties. The crystalline BP in the LC epoxy resin-based nanocomposite was partially melted during exothermic photopolymerization, and the resin expanded via an order-to-disorder transition. Thus, the post-gelation shrinkage of the LC epoxy resin-based nanocomposite is greatly reduced, ∼50.6% less than in commercialized methacrylate resin-based composites. This LC epoxy nanocomposite demonstrates good physical and chemical properties and good biocompatibility

  9. FEATURES OF RESTORATION OF DISPERSE POROUS MATERIALS

    Directory of Open Access Journals (Sweden)

    S. L. Rovin

    2016-01-01

    Full Text Available The article presents the results of research recycling of dispersed materials in rotary furnaces. Has been received new data on the of heat and mass transfer processes and carry out intensive and continuous process of solid- liquid-phase reduction of oxides in a single unit.

  10. New Design for Rapid Prototyping of Digital Master Casts for Multiple Dental Implant Restorations.

    Science.gov (United States)

    Romero, Luis; Jiménez, Mariano; Espinosa, María Del Mar; Domínguez, Manuel

    2015-01-01

    This study proposes the replacement of all the physical devices used in the manufacturing of conventional prostheses through the use of digital tools, such as 3D scanners, CAD design software, 3D implants files, rapid prototyping machines or reverse engineering software, in order to develop laboratory work models from which to finish coatings for dental prostheses. Different types of dental prosthetic structures are used, which were adjusted by a non-rotatory threaded fixing system. From a digital process, the relative positions of dental implants, soft tissue and adjacent teeth of edentulous or partially edentulous patients has been captured, and a maser working model which accurately replicates data relating to the patients oral cavity has been through treatment of three-dimensional digital data. Compared with the conventional master cast, the results show a significant cost savings in attachments, as well as an increase in the quality of reproduction and accuracy of the master cast, with the consequent reduction in the number of patient consultation visits. The combination of software and hardware three-dimensional tools allows the optimization of the planning of dental implant-supported rehabilitations protocol, improving the predictability of clinical treatments and the production cost savings of master casts for restorations upon implants.

  11. New Design for Rapid Prototyping of Digital Master Casts for Multiple Dental Implant Restorations.

    Directory of Open Access Journals (Sweden)

    Luis Romero

    Full Text Available This study proposes the replacement of all the physical devices used in the manufacturing of conventional prostheses through the use of digital tools, such as 3D scanners, CAD design software, 3D implants files, rapid prototyping machines or reverse engineering software, in order to develop laboratory work models from which to finish coatings for dental prostheses. Different types of dental prosthetic structures are used, which were adjusted by a non-rotatory threaded fixing system.From a digital process, the relative positions of dental implants, soft tissue and adjacent teeth of edentulous or partially edentulous patients has been captured, and a maser working model which accurately replicates data relating to the patients oral cavity has been through treatment of three-dimensional digital data.Compared with the conventional master cast, the results show a significant cost savings in attachments, as well as an increase in the quality of reproduction and accuracy of the master cast, with the consequent reduction in the number of patient consultation visits. The combination of software and hardware three-dimensional tools allows the optimization of the planning of dental implant-supported rehabilitations protocol, improving the predictability of clinical treatments and the production cost savings of master casts for restorations upon implants.

  12. New Design for Rapid Prototyping of Digital Master Casts for Multiple Dental Implant Restorations

    Science.gov (United States)

    Romero, Luis; Jiménez, Mariano; Espinosa, María del Mar; Domínguez, Manuel

    2015-01-01

    Aim This study proposes the replacement of all the physical devices used in the manufacturing of conventional prostheses through the use of digital tools, such as 3D scanners, CAD design software, 3D implants files, rapid prototyping machines or reverse engineering software, in order to develop laboratory work models from which to finish coatings for dental prostheses. Different types of dental prosthetic structures are used, which were adjusted by a non-rotatory threaded fixing system. Method From a digital process, the relative positions of dental implants, soft tissue and adjacent teeth of edentulous or partially edentulous patients has been captured, and a maser working model which accurately replicates data relating to the patients oral cavity has been through treatment of three-dimensional digital data. Results Compared with the conventional master cast, the results show a significant cost savings in attachments, as well as an increase in the quality of reproduction and accuracy of the master cast, with the consequent reduction in the number of patient consultation visits. The combination of software and hardware three-dimensional tools allows the optimization of the planning of dental implant-supported rehabilitations protocol, improving the predictability of clinical treatments and the production cost savings of master casts for restorations upon implants. PMID:26696528

  13. A prospective 8-year follow-up of posterior resin composite restorations in permanent teeth of children and adolescents in Public Dental Health Service: reasons for replacement

    DEFF Research Database (Denmark)

    Pallesen, Ulla; van Dijken, Jan W.V.; Halken, Jette

    2014-01-01

    in general practice showed a good durability with annual failure rates of 2 %. The main reason for failure was secondary caries followed by post-operative sensitivity and resin composite fracture. A high proportion of replaced/repaired RC restorations were caused by primary caries in a non-filled surface......Objectives: the aim of the study was to investigate reasons for replacement and repair of posterior resin composite (RC) restorations placed in permanent teeth of children and adolescents attending Public Dental Health Service in Denmark. Material and method: all posterior RC placed consecutively...... by 115 dentists over a period of 4 years were evaluated at baseline and up to 8 years later. The endpoint of each restoration was defined when repair or replacement was performed. The influence of patient, dentist and material factors on reasons for repair or replacement was investigated. Results...

  14. Direct mechanical data acquisition of dental impressions for the manufacturing of CAD/CAM restorations.

    Science.gov (United States)

    Quaas, Sebastian; Rudolph, Heike; Luthardt, Ralph G

    2007-12-01

    The basic prerequisite for the production of dental restorations by means of CAD/CAM technologies is the data acquisition (digitization). Currently, two methods are available, i.e. the extraoral digitization of master casts and the direct intraoral data acquisition. However, it seems to be beneficial to immediately digitize impressions directly at the dental office in order to combine the high precision of mechanical digitizing methods and to shorten the production process. The aim of this study was to investigate the measurement uncertainty (+/-2sigma) and the three-dimensional accuracy of the immediate tactile in-office digitization of dental impressions and of the mechanical digitizing of ceramic master dies using a high-precision touch-probe digitizer. The experimental set-up consisted of ceramic master dies representing tooth 13 and 36 as well as their identical virtual models (CAD models). Fifteen one-step putty-wash impressions were taken from each tooth. The impressions as well as the ceramic master dies were digitized applying a standardized procedure. The datasets were aligned to the corresponding CAD models; then, a computer-aided three-dimensional analysis was performed. The digitizing of the dental impressions showed a measurement uncertainty of 5.8, mean positive deviations between 27 and 28microm, and mean negative deviations between -21 and -31microm. The digitizing of the ceramic master dies showed a measurement uncertainty of 2.8, mean positive deviations between 7.7 and 9.1microm, and mean negative deviations between -8.5 and -8.8microm. Mechanical digitizers show a very low measurement uncertainty and a high precision. The immediate tactile in-office digitization of impressions cannot be recommended as adequate data acquisition method for CAD/CAM restorations. It is recommendable to digitize clinical sites extraorally, i.e. after taking an impression and fabricating a model cast thereof.

  15. DEGREE OF AWARENESS OF SOFT RELINING MATERIALS BY DENTAL TECHNICIANS

    Directory of Open Access Journals (Sweden)

    Ilian Hristov

    2017-10-01

    Full Text Available The aim of the current investigation is to analyze the dental-technicians’ awareness of the soft relining materials, their characteristics, advantages, shortcomings and methods for relining. Materials and methods: For the purpose of this investigation a standard questionnaire has been presented. A direct survey method, documentary and statistical method, as well as graphical methods, including tables, charts, graphics and figures, were used. Data were analysed with the help of IBM SPSS Statistics (ver. 19. Results: One hundred and eight dental technicians were included in the survey, evenly distributed by gender. Removable and fixed prosthodontics is the most commonly mentioned spheres of dental activities. Almost all included in the investigation point out the laboratory relining method as the most frequently used. Acrylic and silicone SRM are the most used groups of relining materials. Change of colour and hardness are the most frequently noticed shortcomings of these materials. The majority of the dental technicians declare that they have never done replacement of SRM or the relining has lasted more than a year. Discussion: The correlation between the age and the years of labour service among the participants is quite obvious. Most of them start working soon after their graduation. Removable prosthodontics is among the priorities for the majority of the labs. Conclusion: Although their unambiguous advantages, the soft relining materials have lots of shortcomings as well. The major problems are connected with their change of colour and hardness. Nevertheless, the dental technicians find them useful and reliable in overcoming specific prosthetic problems.

  16. Association and comparison between visual inspection and bitewing radiography for the detection of recurrent dental caries under restorations.

    Science.gov (United States)

    Lino, José R; Ramos-Jorge, Joana; Coelho, Valéria Silveira; Ramos-Jorge, Maria L; Moysés, Marcos R; Ribeiro, José C R

    2015-08-01

    The aim of the present study was to investigate, in posterior teeth, the association between the characteristics of the margins of a restoration visually inspected and the presence, under restorations, of recurrent or residual dental caries detected by radiographic examination. Furthermore, the agreement between visual inspection and radiographs to detect dental caries was assessed. Eighty-five permanent molars and premolars with resin restorations on the interproximal and/or occlusal faces, from 18 patients, were submitted for visual inspection and radiographic examination. The visual inspection involved the criteria of the International Caries Detection and Assessment System (ICDAS). Bitewing radiographs were used for the radiographic examination. Logistic regression was used to analyse the association between the characteristics of the margins of a restoration assessed by visual inspection (absence of dental caries, or early, established, inactive and active lesions) and the presence of recurrent caries detected by radiographs. Kappa coefficients were calculated for determining agreement between the two methods. The Kappa coefficient for agreement between visual inspection and radiographic examination was 0.19. Established lesions [odds ratio (OR) = 9.89; 95% confidence interval (95% CI): 2.94-33.25; P caries detected by radiographs. Restorations with established and active lesions at the margins had a greater chance of exhibiting recurrent or residual lesions in the radiographic examination. The present findings demonstrate that restorations with established and active lesions at the margins when visually inspected often require removal and retreatment. © 2015 FDI World Dental Federation.

  17. Recent Advances in Material and Geometrical Modelling in Dental Applications

    Directory of Open Access Journals (Sweden)

    Waleed M. S. Al Qahtani

    2018-06-01

    Full Text Available This article touched, in brief, the recent advances in dental materials and geometric modelling in dental applications. Most common categories of dental materials as metallic alloys, composites, ceramics and nanomaterials were briefly demonstrated. Nanotechnology improved the quality of dental biomaterials. This new technology improves many existing materials properties, also, to introduce new materials with superior properties that covered a wide range of applications in dentistry. Geometric modelling was discussed as a concept and examples within this article. The geometric modelling with engineering Computer-Aided-Design (CAD system(s is highly satisfactory for further analysis or Computer-Aided-Manufacturing (CAM processes. The geometric modelling extracted from Computed-Tomography (CT images (or its similar techniques for the sake of CAM also reached a sufficient level of accuracy, while, obtaining efficient solid modelling without huge efforts on body surfaces, faces, and gaps healing is still doubtable. This article is merely a compilation of knowledge learned from lectures, workshops, books, and journal articles, articles from the internet, dental forum, and scientific groups' discussions.

  18. New materials for structural restoration: an old debate

    Directory of Open Access Journals (Sweden)

    Federica Ottoni

    2015-12-01

    Full Text Available The use of composites in architectural restoration is becoming more and more widespread, due to their technical advantages, in many cases. However, using these materials in the field of cultural heritage creates not only technical problems but also cultural issues. The paper deals with these issues, starting from some considerations on the use of “new” materials in the past, when – just to mention some examples – iron, steel and reinforced concrete were considered innovative. From Ruskin’s idea of  “crutch”, passing to the “hidden reinforcement” expressed in the Athens Charter, to some more recent examples, the past experiences offer once again the opportunity to evaluate new techniques and theoretical approaches. The authors underline the opportunity to identify a “correct methodology” rather than a “correct solution” in restoration.  Further knowledge and comprehension of a monument and – at the same time - a deep awareness of the limits and weaknesses of recent technologies and materials, may guide architects to a more efficient, respectful structural restoration project. Keywords: restoration, structure, materials, reinforcement, technique

  19. Do Dental Resin Composites Accumulate More Oral Biofilms and Plaque than Amalgam and Glass Ionomer Materials?

    Directory of Open Access Journals (Sweden)

    Ning Zhang

    2016-11-01

    Full Text Available A long-time drawback of dental composites is that they accumulate more biofilms and plaques than amalgam and glass ionomer restorative materials. It would be highly desirable to develop a new composite with reduced biofilm growth, while avoiding the non-esthetics of amalgam and low strength of glass ionomer. The objectives of this study were to: (1 develop a protein-repellent composite with reduced biofilms matching amalgam and glass ionomer for the first time; and (2 investigate their protein adsorption, biofilms, and mechanical properties. Five materials were tested: A new composite containing 3% of protein-repellent 2-methacryloyloxyethyl phosphorylcholine (MPC; the composite with 0% MPC as control; commercial composite control; dental amalgam; resin-modified glass ionomer (RMGI. A dental plaque microcosm biofilm model with human saliva as inoculum was used to investigate metabolic activity, colony-forming units (CFU, and lactic acid production. Composite with 3% MPC had flexural strength similar to those with 0% MPC and commercial composite control (p > 0.1, and much greater than RMGI (p < 0.05. Composite with 3% MPC had protein adsorption that was only 1/10 that of control composites (p < 0.05. Composite with 3% MPC had biofilm CFU and lactic acid much lower than control composites (p < 0.05. Biofilm growth, metabolic activity and lactic acid on the new composite with 3% MPC were reduced to the low level of amalgam and RMGI (p > 0.1. In conclusion, a new protein-repellent dental resin composite reduced oral biofilm growth and acid production to the low levels of non-esthetic amalgam and RMGI for the first time. The long-held conclusion that dental composites accumulate more biofilms than amalgam and glass ionomer is no longer true. The novel composite is promising to finally overcome the major biofilm-accumulation drawback of dental composites in order to reduce biofilm acids and secondary caries.

  20. ‍Correlation between the scores of dental students in theory and practical restoration courses from 1991 till 2012

    OpenAIRE

    A. R. Danesh kazemi; A. R. Davari; M. Momeni Sarvestani

    2013-01-01

    Introduction: In order to codify a better curriculum and develop the quality of education, continuous monitoring dental students' education during their study is necessary. This study was conducted on the course scores of dental students of Shahid Sadoughi University of Medical Sciences from 1991 till 2012 on the theory and practical restoration courses. The correlation between these scores was investigated. Methods: This was a cross-sectional study which was performed retrospectively on all ...

  1. Materials and methods for autonomous restoration of electrical conductivity

    Science.gov (United States)

    Blaiszik, Benjamin J; Odom, Susan A; Caruso, Mary M; Jackson, Aaron C; Baginska, Marta B; Ritchey, Joshua A; Finke, Aaron D; White, Scott R; Moore, Jeffrey S; Sottos, Nancy R; Braun, Paul V; Amine, Khalil

    2014-03-25

    An autonomic conductivity restoration system includes a solid conductor and a plurality of particles. The particles include a conductive fluid, a plurality of conductive microparticles, and/or a conductive material forming agent. The solid conductor has a first end, a second end, and a first conductivity between the first and second ends. When a crack forms between the first and second ends of the conductor, the contents of at least a portion of the particles are released into the crack. The cracked conductor and the released contents of the particles form a restored conductor having a second conductivity, which may be at least 90% of the first conductivity.

  2. Influence of dental bleaching on marginal leakage of Class V restorations

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    Andréia Cristina Ramos Dorini

    2010-04-01

    Full Text Available Objective: Evaluate the in vitro effect of bleaching performed in the dental office and waiting time on the degree of microleakage in class V cavities with margins in enamel, restored with resin composite. Methods: Forty-five human third molars were used, in which the vestibular faces were bleached with 35% hydrogen peroxide activated with LED and the palatine faces were not bleached (control. The teeth were randomly divided into 3 groups with 15 teeth in each: Group 1, restored immediately after bleaching; Group 2, seven days after bleaching; and Group 3, fourteen days after bleaching. After cavity preparation, 35% phosphoric acid, Adper Single Bond 2 adhesive (3M ESPE, St. Paul, Mn, USA, and resin composite Filtek Z250 (3M ESPE, St. Paul, MN, USA were applied. The teeth were thermal cycled and sealed with red nail polish on the bleached faces and blue on the non bleached faces, except for 1mm around the restored region. The samples were classified according to the following scores: 0 = no leakage, 1 = minimum leakage (less than 1 / 3 the length of the wall, 2 = moderate leakage (1/3 to 2/3 of the wall and 3 = extensive leakage (over 2/3 of the wall. The data were submitted to the Kruskal-Wallis test at a level of significance of 5%. Results: The restorative procedure immediately after bleaching resulted in statistically higher microleakage values (p 0.05. Conclusion: Based on the results, it is advisable to wait at least 7 days after bleaching to make the definitive restoration.

  3. An experimental bioactive dental ceramic for metal-ceramic restorations: Textural characteristics and investigation of the mechanical properties.

    Science.gov (United States)

    Goudouri, Ourania-Menti; Kontonasaki, Eleana; Papadopoulou, Lambrini; Manda, Marianthi; Kavouras, Panagiotis; Triantafyllidis, Konstantinos S; Stefanidou, Maria; Koidis, Petros; Paraskevopoulos, Konstantinos M

    2017-02-01

    The aim of this study was the evaluation of the textural characteristics of an experimental sol-gel derived feldspathic dental ceramic, which has already been proven bioactive and the investigation of its flexural strength through Weibull Statistical Analysis. The null hypothesis was that the flexural strength of the experimental and the commercial dental ceramic would be of the same order, resulting in a dental ceramic with apatite forming ability and adequate mechanical integrity. Although the flexural strength of the experimental ceramics was not statistically significant different compared to the commercial one, the amount of blind pores due to processing was greater. The textural characteristics of the experimental ceramic were in accordance with the standard low porosity levels reported for dental ceramics used for fixed prosthetic restorations. Feldspathic dental ceramics with typical textural characteristics and advanced mechanical properties as well as enhanced apatite forming ability can be synthesized through the sol-gel method. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Influence of metal dental materials on MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Tsuchihashi, Toshio; Chiba, Michiko; Yoshizawa, Satoshi; Sasaki, Sadayuki; Maki, Toshio; Kitagawa, Matsuo; Suzuki, Takeshi [Nippon Medical School, Tokyo (Japan). Main Hospital; Nakata, Minoru; Fujita, Isao

    1998-11-01

    Differences in magnetic susceptibility produce artifacts and signal loss in magnetic resonance imaging (MRI). This study was undertaken to compare the degree of artifacts on MRI caused by metallic dental materials. The influence on MRI of six types of dental alloys, a dental implant, orthodontic appliance, and magnetic attachment was investigated. Among the dental metals, nickel-chromium alloy and cobalt-chromium alloy, which have ferromagnetism, caused significant metal artifacts. Gold-platinum alloy, gold-silver-palladium alloy, silver alloy, and amalgam alloy produced slight metal artifacts. The orthodontic appliance mainly consisted of iron, and the keeper for its magnetic attachment was made of stainless steel. For these reasons, marked metal artifacts and signal loss could be seen in both of them owing to their ferromagnetism. These results suggest that orthodontic appliances and magnetic attachments impair evaluation of the GRE and EPI techniques. It is therefore preferable to use predominantly diamagnetic or paramagnetic dental materials for MRI of the head and neck. Removable keepers should be used more widely to prevent metal artifacts and enhance safety on MRI. (author)

  5. Influence of metal dental materials on MR imaging

    International Nuclear Information System (INIS)

    Tsuchihashi, Toshio; Chiba, Michiko; Yoshizawa, Satoshi; Sasaki, Sadayuki; Maki, Toshio; Kitagawa, Matsuo; Suzuki, Takeshi; Nakata, Minoru; Fujita, Isao

    1998-01-01

    Differences in magnetic susceptibility produce artifacts and signal loss in magnetic resonance imaging (MRI). This study was undertaken to compare the degree of artifacts on MRI caused by metallic dental materials. The influence on MRI of six types of dental alloys, a dental implant, orthodontic appliance, and magnetic attachment was investigated. Among the dental metals, nickel-chromium alloy and cobalt-chromium alloy, which have ferromagnetism, caused significant metal artifacts. Gold-platinum alloy, gold-silver-palladium alloy, silver alloy, and amalgam alloy produced slight metal artifacts. The orthodontic appliance mainly consisted of iron, and the keeper for its magnetic attachment was made of stainless steel. For these reasons, marked metal artifacts and signal loss could be seen in both of them owing to their ferromagnetism. These results suggest that orthodontic appliances and magnetic attachments impair evaluation of the GRE and EPI techniques. It is therefore preferable to use predominantly diamagnetic or paramagnetic dental materials for MRI of the head and neck. Removable keepers should be used more widely to prevent metal artifacts and enhance safety on MRI. (author)

  6. A systematic review of prosthetic restoration in patients with shortened dental arches

    Directory of Open Access Journals (Sweden)

    Kenji Fueki

    2011-08-01

    Full Text Available The literature regarding the effect of prosthetic restoration in patients having distal extension edentulous space in posterior area (shortened dental arch: SDA is reviewed in the following article. Information retrieval followed a systematic approach using PubMed. Articles in English published between 1966 and March 2011 describing the outcome of treatment with various prostheses were evaluated. From the search results of 98 articles, 21 articles met the inclusion criteria. Treatment with removable partial dentures (RPDs improved masticatory function, patient satisfaction and oral health-related quality of life (OHRQoL. However, no significant difference was found in the outcomes between patients with RPDs and with cantilever fixed partial dentures (CFPDs. Caries developed more frequently after treatment with RPDs than CFPDs. The time to survival for CFPDs was not longer than that for RPDs, while more visits to maintain RPDs were required than for CFPDs. No significant difference was found in masticatory function, OHRQoL, and occlusal stability between patients with RPDs and those without restoration of missing molars. Consequently, treatment with RPDs for SDA seems to be less advantageous than CFPDs or no restoration for missing molars. Further research is required to validate treatment with implant-supported fixed partial dentures for SDA.

  7. Reduction of metal artifact in three-dimensional computed tomography (3D CT) with dental impression materials.

    Science.gov (United States)

    Park, W S; Kim, K D; Shin, H K; Lee, S H

    2007-01-01

    Metal Artifact still remains one of the main drawbacks in craniofacial Three-Dimensional Computed Tomography (3D CT). In this study, we tried to test the efficacy of additional silicone dental impression materials as a "tooth shield" for the reduction of metal artifact caused by metal restorations and orthodontic appliances. 6 phantoms with 4 teeth were prepared for this in vitro study. Orthodontic bracket, bands and amalgam restorations were placed in each tooth to reproduce various intraoral conditions. Standardized silicone shields were fabricated and placed around the teeth. CT image acquisition was performed with and without silicone shields. Maximum value, mean, and standard deviation of Hounsfield Units (HU) were compared with the presence of silicone shields. In every situation, metal artifacts were reduced in quality and quantity when silicone shields are used. Amalgam restoration made most serious metal artifact. Silicone shields made by dental impression material might be effective way to reduce the metal artifact caused by dental restoration and orthodontic appliances. This will help more excellent 3D image from 3D CT in craniofacial area.

  8. Influence of dental filling material type on the concentration of interleukin 9 in the samples of gingival crevicular fluid

    Directory of Open Access Journals (Sweden)

    Stefanović Vladimir

    2016-01-01

    Full Text Available Background/Aim. Several cytokines and lymphokines (IL1β, ENA78, IL6, TNFα, IL8 and S100A8 are expressed during dental pulp inflammation. Analysis of gingival crevicu-lar fluid (GCF offers a non-invasive means of studying gen-eral host response in oral cavity. Although GCF levels of various mediators could reflect the state of inflammation both in dental pulp and gingiva adjacent to a tooth, GCF samples of those without significant gingivitis could be inter-preted as reflection of pulpal process. The aim of this study was to investigate IL9 GCF values in patients with dental car-ies and to assess possible influence of various dental fillings materials on local IL9 production. Methods. The study group included 90 patients, aged 18–70, with inclusion and exclusion criteria in the prospective clinical study. Of the 6 types of material used for the restoration of prepared cavities, 3 were intended for temporary and 3 for definitive restora-tion. According to dental fillings weight, all the participants were divided into 3 groups: those with fillings lighter than 0.50 g, those with 0.50–1.00 g, and those with fillings heavier than 1.00 g. Samples were taken from gingival sulcus using the filter paper technique. Clinical parameters were deter-mined by bleeding index, plaque index (Silness-Lou, 0–3, gingival index (0–3, and gingival sulcus depth. Cytokine con-centrations were assessed using commercially available cy-tomix. Results. According to the weight of dental fillings, there was a clear decreament trend of IL9 values meaning that dental defects greater than 1.00 g of dental filling were associated with lower GCF IL9 concentration. The IL9 val-ues correlated with the degree of gingival index and depth of gingival sulcus, being higher with more advanced gingivitis and more pronounced anatomical changes in the tooth edge. Different filling materials exerted various local IL9 responses. Zink polycarbonate cement and amalgam fillings induced

  9. Effect of bleaching on microhardness of esthetic restorative materials.

    Science.gov (United States)

    Malkondu, Özlem; Yurdagüven, Haktan; Say, Esra Can; Kazazoğlu, Ender; Soyman, Mübin

    2011-01-01

    This study evaluated the effect of a high-concentration carbamide peroxide–containing home bleaching system (Opalescence PF) and a hydrogen peroxide–containing over-the-counter bleaching system (Treswhite Supreme) on the microhardness of two nanocomposites (Filtek Supreme XT and Premise) and leucite-reinforced glass ceramic (Empress Esthetic), glass ceramic (Empress 2 layering), and feldspathic porcelain (Matchmaker MC). A total of 100 specimens, 20 of each kind of the restorative materials, 2 mm in thickness and 10 mm in diameter, were fabricated. Then the specimens were polished with SiC paper and 1 μm alumina polishing paste. After polishing, porcelain specimens were glazed in accordance with the manufacturer's instructions. Each type of restorative material was then randomly divided into two groups (n=10), and the specimens were treated with either Opalescence PF or Treswhite Supreme. The microhardness of the specimens before bleaching (baseline) and after bleaching was determined using a digital microhardness tester. Data were analyzed using the Mann-Whitney U-test and the Wilcoxon test. Opalescence PF significantly influenced the hardness of all the restorative materials. Statistically significant decreases with respect to before bleaching were found for Premise (p=0.005), Empress Esthetic (p=0.003), Empress 2 layering (p=0.005), and Matchmaker-MC (p=0.003), whereas a statistically significant increase was observed in Filtek Supreme XT (p=0.028). The difference in the microhardness values between before and after bleaching using Treswhite Supreme was statistically significant only for Premise (p=0.022). High-concentration carbamide peroxide–containing home bleaching may affect the microhardness of restorative materials.

  10. Evaluation of color stability of different temporary restorative materials

    Directory of Open Access Journals (Sweden)

    José Vitor Quinelli Mazaro

    Full Text Available AbstractIntroductionTemporary restorative materials are widely used, however, little is know about their color stability.Objectiveto evaluate the color stability of the following temporary restorative materials: acrylic and bis-acrylic resins after immersion in pigmenting solutions for different periods of storage.Material and methodFour materials were tested (Dêncor/Clássico, Protemp 4/3M ESPE; Structur 2 SC/Voco; Luxatemp AM Plus/DMG and 30 test specimens (15 mm in diameter and 2 mm thick per material were fabricated. They were divided according to the storage medium (artificial saliva, saliva + cola type soda, and saliva + coffee and storage time intervals (2, 5, 7 and 15 days. Color measurements were made before and after immersions, with use of a spectrophotometer, by means of the CIE L*a*b* system. The data were analyzed by the analysis of variance and the Tukey Test, at a level of significance of 5%.ResultAcrylic resin presented greater color stability in comparison with bis-acrylic resins (p<0.001. When bis-acrylic resins were compared no significant difference was observed between the resins Structur and Luxatemp (p=0.767. As regards solutions tested, coffee showed the highest color change values (p<0.001, and the longer the storage time interval, the greater was the color change in all the temporary restorative materials analyzed (p<0.001.ConclusionAcrylic resin presented greater color stability in comparison with bis-acrylic resins (p<0.001. Coffee caused the greatest color change, and immersion time was determinant in color stability of the temporary materials analyzed.

  11. In vitro color stability of provisional restorative materials.

    Science.gov (United States)

    Jalali, Hamid; Dorriz, Hassan; Hoseinkhezri, Farzaneh; Emadian Razavi, S F

    2012-01-01

    Discoloration of provisional restorations can result in esthetic problems which are critically important in, for example, anterior areas and may compromise the acceptability of the restoration. The purpose of this study was to investigate the effect of tea on provisional restorative materials. This study was designed to measure the degree of color change of three acrylic resin provisional materials, before and after immersion in artificial saliva and artificial saliva-tea solution for 2 and 4 weeks. Three types of acrylic provisional materials (duralay, tempron, acropars TRP), were studied. Twenty disks (20 ± 0.1 mm by 2 ± 0.05 mm) were fabricated from each material. Specimens were polished with acrylic bur using pumice and diamond polishing paste. Base line color was measured using a spectrophotometer. Ten disks were stored in artificial saliva and 10 were stored in a solution of artificial saliva and tea at room temperature. Color measurements were made after 2 and 4 weeks of immersion. Differences in color changes were compared by two way ANOVA, across the six groups, followed by a Turkey-Kramer's multiple comparison test. For specimens immersed in artificial saliva, the color change of methyl methacrylate materials; duralay (ΔE=4.94) and tempron (ΔE=6.54), was significantly more than butyl methacrylate material; acropars (ΔE=4.10). After immersion in an artificial saliva- tea solution, tempron exhibited less color change (ΔE=8.50) compared to duralay (ΔE=10.93) and acropars (ΔE=15.64). Color stability of methyl methacrylate is higher than butyl methacrylates so if provisional materials are used for extended periods of time; tempron is preferred.

  12. Influence of dental restorations and mastication loadings on dentine fatigue behaviour: Image-based modelling approach.

    Science.gov (United States)

    Vukicevic, Arso M; Zelic, Ksenija; Jovicic, Gordana; Djuric, Marija; Filipovic, Nenad

    2015-05-01

    The aim of this study was to use Finite Element Analysis (FEA) to estimate the influence of various mastication loads and different tooth treatments (composite restoration and endodontic treatment) on dentine fatigue. The analysis of fatigue behaviour of human dentine in intact and composite restored teeth with root-canal-treatment using FEA and fatigue theory was performed. Dentine fatigue behaviour was analysed in three virtual models: intact, composite-restored and endodontically-treated tooth. Volumetric change during the polymerization of composite was modelled by thermal expansion in a heat transfer analysis. Low and high shrinkage stresses were obtained by varying the linear shrinkage of composite. Mastication forces were applied occlusally with the load of 100, 150 and 200N. Assuming one million cycles, Fatigue Failure Index (FFI) was determined using Goodman's criterion while residual fatigue lifetime assessment was performed using Paris-power law. The analysis of the Goodman diagram gave both maximal allowed crack size and maximal number of cycles for the given stress ratio. The size of cracks was measured on virtual models. For the given conditions, fatigue-failure is not likely to happen neither in the intact tooth nor in treated teeth with low shrinkage stress. In the cases of high shrinkage stress, crack length was much larger than the maximal allowed crack and failure occurred with 150 and 200N loads. The maximal allowed crack size was slightly lower in the tooth with root canal treatment which induced somewhat higher FFI than in the case of tooth with only composite restoration. Main factors that lead to dentine fatigue are levels of occlusal load and polymerization stress. However, root canal treatment has small influence on dentine fatigue. The methodology proposed in this study provides a new insight into the fatigue behaviour of teeth after dental treatments. Furthermore, it estimates maximal allowed crack size and maximal number of cycles for a

  13. Effects of build direction on the mechanical properties of 3D-printed complete coverage interim dental restorations

    NARCIS (Netherlands)

    Alharbi, N.; Osman, R.; Wismeijer, D.

    2016-01-01

    Statement of problem. The application of 3-dimensional printing technology is emerging in dentistry and is being increasingly used to fabricate dental restorations. To date, scientific evidence is lacking regarding the effect of different factors on the mechanical properties of the printed

  14. The relative patient costs and availability of dental services, materials and equipment in public oral care facilities in Tanzania.

    Science.gov (United States)

    Nyamuryekung'e, Kasusu K; Lahti, Satu M; Tuominen, Risto J

    2015-07-01

    Patient charges and availability of dental services influence utilization of dental services. There is little available information on the cost of dental services and availability of materials and equipment in public dental facilities in Africa. This study aimed to determine the relative cost and availability of dental services, materials and equipment in public oral care facilities in Tanzania. The local factors affecting availability were also studied. A survey of all district and regional dental clinics in selected regions was conducted in 2014. A total of 28/30 facilities participated in the study. A structured interview was undertaken amongst practitioners and clinic managers within the facilities. Daily resources for consumption (DRC) were used for estimation of patients' relative cost. DRC are the quantified average financial resources required for an adult Tanzanian's overall consumption per day. Tooth extractions were found to cost four times the DRC whereas restorations were 9-10 times the DRC. Studied facilities provided tooth extractions (100%), scaling (86%), fillings (79%), root canal treatment (46%) and fabrication of removable partial dentures (32%). The ratio of tooth fillings to extractions in the facilities was 1:16. Less than 50% of the facilities had any of the investigated dental materials consistently available throughout the year, and just three facilities had all the investigated equipment functional and in use. Dental materials and equipment availability, skills of the practitioners and the cost of services all play major roles in provision and utilization of comprehensive oral care. These factors are likely to be interlinked and should be taken into consideration when studying any of the factors individually.

  15. Dental sealants and restorations and urinary bisphenol A concentrations in children in the 2003-2004 National Health and Nutrition Examination Survey.

    Science.gov (United States)

    McKinney, Christy; Rue, Tessa; Sathyanarayana, Sheela; Martin, Michael; Seminario, Ana Lucia; DeRouen, Timothy

    2014-07-01

    Resin-based dental sealants and composites contain bisphenol A-glycidyl methacrylate, a bisphenol A (BPA) derivative. The authors hypothesized that a greater number of sealants or restorations would be associated with higher urinary BPA concentrations. The authors examined urinary BPA measurements (in nanograms per milliliter) and oral examination data for 1,001 children aged 6 to 19 years from data sets of the 2003-2004 National Health and Nutrition Examination Survey (NHANES). They categorized children according to number of occlusal sealants and number of restorations, with four categories in each of the two groups. They estimated associations by using unadjusted and adjusted tobit regression models. The lowest quartile of BPA concentrations ranged from 0.3 ng/mL to 1.9 ng/mL, whereas the highest quartile ranged from 7.3 ng/mL to 149 ng/mL. In adjusted analysis, children with seven to 16 sealants had geometric mean BPA concentrations 25 percent higher than those of children with no sealants (95 percent confidence interval [CI], -14 percent to 82 percent; P = .23). In adjusted analysis, children with seven to 42 restorations had geometric mean BPA concentrations 20 percent higher than those of children with no restorations (95 percent CI, -6 percent to 53 percent; P = .13). Neither of these adjusted estimates was statistically significant. Though the findings were in the direction hypothesized, the authors did not observe a statistically significant association between a greater number of sealants or restorations and higher urinary BPA concentrations. Additional studies are needed to determine the extent of oral and systemic exposure to BPA from resin-based dental restorative materials over time. Dentists should follow this issue carefully as it develops and as the body of evidence grows. There is insufficient evidence to change practice at this time.

  16. Characterization and human gingival fibroblasts biocompatibility of hydroxyapatite/PMMA nanocomposites for provisional dental implant restoration

    Science.gov (United States)

    Zhang, Jingchao; Liao, Juan; Mo, Anchun; Li, Yubao; Li, Jidong; Wang, Xuejiang

    2008-11-01

    The aim of this study was to determine nHA/PMMA composites (H/P) in an optimal ratio with improved cytocompatibility as well as valid physical properties for provisional dental implant restoration. 20 wt.%, 30 wt.%, 40 wt.% and 50 wt.% H/P were developed and characterized using XPS, bending strength test and SEM. Human gingival fibroblasts cultured in extracts or directly on sample discs were investigated by fluorescent staining and MTT assay. Chemical integration in nHA/PMMA interface was indicated by XPS. Typical fusiform cells with adhesion spots were detected on H/P discs. MTT results also indicated higher cell viability in 30 wt.% and 40 wt.% H/P discs ( P provisional fixed crowns (PFC) is 0.4:1.

  17. Clinical evaluation of combined surgical/ restorative treatment of gingival recession-type defects using different restorative materials: A randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Sila Cagri Isler

    2018-03-01

    Full Text Available Background/purpose: An ideal therapeutic procedure for the treatment of gingival recession associated with an NCCL has presented a challenge to clinicians. Various dental materials and surgical approaches have been used to manage gingival recessions associated with NCCLs for the most predictable combined surgical/restorative treatment. The objective of this study was to evaluate the treatment of gingival recessions associated with non-carious cervical lesions (NCCL using a modified coronally advanced flap (MCAF in combination with a connective tissue graft (CTG on restored root surfaces. Materials and methods: Twenty-three systemically healthy subjects, who were positive for the presence of three cervical lesions associated with gingival recessions in three different adjacent teeth, were enrolled in the study. The NCCL were each restored prior to surgery by using one of three different materials: nanofilled composite resin (NCR, resin-modified glass ionomer cement (RMGI or giomer. The gingival recession defects were treated by CTG. Results: Inter-group differences were not statistically significant for probing depth (PD, relative recession height (rRH, relative clinical attachment level (rCAL, keratinized tissue width (KTW or keratinized tissue thickness (KTT (p > 0.05 among the groups at any time. The mean percentage of defect coverage was 71.18 ± 23.16% for NCR + CTG group; 71.33 ± 22.33% for RMGI + CTG group; and 64.23 ± 20.33% for giomer + CTG group at 1 year postoperatively (p > 0.05. Conclusion: The combined surgical/restorative treatments provided successful clinical results. Giomer + CTG may be less effective compared to other groups for treatment of gingival recession associated with NCCL. Keywords: cervical lesions, connective tissue grafts, gingival recession, restorative materials

  18. Anisotropic local physical properties of human dental enamel in comparison to properties of some common dental filling materials.

    Science.gov (United States)

    Raue, Lars; Hartmann, Christiane D; Rödiger, Matthias; Bürgers, Ralf; Gersdorff, Nikolaus

    2014-11-01

    A major aspect in evaluating the quality of dental materials is their physical properties. Their properties should be a best fit of the ones of dental hard tissues. Manufacturers give data sheets for each material. The properties listed are characterized by a specific value. This assumes (but does not prove) that there is no direction dependence of the properties. However, dental enamel has direction-dependent properties which additionally vary with location in the tooth. The aim of this paper is to show the local direction dependence of physical properties like the elastic modulus or the thermal expansion in dental hard tissues. With this knowledge the 'perfect filling/dental material' could be characterized. Enamel sections of ∼400-500 μm thickness have been cut with a diamond saw from labial/buccal to palatal/lingual (canine, premolar and molar) and parallel to labial (incisor). Crystallite arrangements have been measured in over 400 data points on all types of teeth with x-ray scattering techniques, known from materials science. X-ray scattering measurements show impressively that dental enamel has a strong direction dependence of its physical properties which also varies with location within the tooth. Dental materials possess only little or no property direction dependence. Therefore, a mismatch was found between enamel and dental materials properties. Since dental materials should possess equal (direction depending) properties, worthwhile properties could be characterized by transferring the directional properties of enamel into a property 'wish list' which future dental materials should fulfil. Hereby the 'perfect dental material' can be characterized.

  19. Effectiveness of benzocaine in reducing deep cavity restoration and post-extraction stress in dental patients

    Directory of Open Access Journals (Sweden)

    Khalid H. Al-Samadani

    2015-11-01

    Full Text Available Objectives: To investigate the effectiveness of topical anesthetic, 20% benzocaine in relieving pain and stress in patients following deep cavity restoration and extraction of teeth under local anesthesia (LA. Methods: A prospective clinical trial was conducted from October 2014 until April 2015 at Taibah University, Al Madinah Al Munawarah, Kingdom of Saudi Arabia. Forty-five patients were included in the 20% benzocaine group, and 46 in the normal saline group. Evaluation of the dental stress was made pre-operatively and immediately post-operative treatment using the visual analogue scale (VAS. Furthermore, discomfort of the injections were recorded by the patients after each treatment on standard 100 mm VAS, tagged at the endpoints with “no pain” (0 mm and “unbearable pain” (100 mm. Results: There were statistically significant differences between the mean stress scores for patients in the benzocaine and normal saline groups post-operatively (p=0.002. There were significant differences between the mean pain scores for patients in the post buccal injection (p=0.001, post palatal injection (p=0.01, and the post inferior alveolar nerve block groups (p=0.02. Buccal, palatal, and inferior alveolar nerve block injections were more painful for patients in the normal saline group than the benzocaine group. Conclusion: This investigation has demonstrated that post-operative stress associated with deep cavity restoration and dental extractions under LA can be reduced by the application of topical anesthetic (20% benzocaine at the operative site for intra-oral injections.

  20. Measurement of absorbed doses near metal and dental material interfaces irradiated by x- and gamma-ray therapy beams

    International Nuclear Information System (INIS)

    Farahani, M.; Eichmiller, F.C.; McLaughlin, W.L.

    1990-01-01

    Soft-tissue damage adjacent to dental restorations is a deleterious side effect of radiation therapy associated with low-energy electron scatter from dental materials of high electron density. This study was designed to investigate the enhancement of dose to soft tissue (or water) close to high electron-density materials and to measure the detailed lateral and depth-dose profiles in soft-tissue-simulating polymer adjacent to planar interfaces of several higher atomic-number materials: 18-carat gold dental casting alloy; Ag-Hg dental amalgam alloy; Ni-Cr dental casting alloy; and natural human tooth structure. Results indicate that the dose-enhancement in 'tissue' is as great as a factor of 2 on the backscatter side adjacent to gold and a factor of 1.2 adjacent to tooth tissue, but is insignificant on the forward-scatter side because of the predominant effect of attenuation by the high-density, high atomic-number absorbing material. (author)

  1. Retrospective analysis of dental implants placed and restored by advanced prosthodontic residents.

    Science.gov (United States)

    Barias, Pamela A; Lee, Damian J; Yuan, Judy Chia-Chun; Sukotjo, Cortino; Campbell, Stephen D; Knoernschild, Kent L

    2013-02-01

    The purposes of this retrospective clinical review were to: (1) describe the demographics of implant patients, types of implant treatment and implant-supported prostheses in an Advanced Education in Prosthodontic Program, (2) evaluate the survival rate of dental implants placed by prosthodontic residents from 2006 to 2008, and (3) analyze the relationship between resident year of training and implant survival rate. All patients who received dental implants placed by prosthodontic residents from January 2006 to October of 2008 in the Advanced Prosthodontic Program at the University of Illinois at Chicago College of Dentistry were selected for this study. Age, gender, implant diameter, length, implant locations, surgical and restorative detail, and year of prosthodontic residency training were collected and analyzed. Life-table and Kaplan-Meier survival analyses were performed based on implants overall, locations, year of training, and use of a computer-generated surgical guide. A Logrank statistic was performed between implant survival and year of prosthodontic residency training, location, and use of computer-generated surgical guide (α= 0.05). Three hundred and six implants were placed, and of these, seven failed. Life-table and Kaplan-Meier analyses computed a cumulative survival rate (CSR) of 97% for overall implants and implants placed with a computer-generated surgical guide. No statistical difference was found in implant survival rates as a function of year of training (P= 0.85). Dental implants placed by prosthodontic residents had a CSR comparable to previously published studies by other specialties. The year of prosthodontic residency training and implant failure rate did not have any significant relationship. © 2012 by the American College of Prosthodontists.

  2. Evaluation of effect of 3D video glasses on perceived pain and unpleasantness induced by restorative dental treatment

    DEFF Research Database (Denmark)

    Bentsen, Bo; Svensson, Peter; Wenzel, Ann

    2001-01-01

    whether distraction induced by video glasses also had an effect on the perceived intensity of pain and unpleasantness during dental treatment. Pain and unpleasantness was evoked by the preparation (drilling) of a minor dental cavity (class I). Twenty-three patients (17 female and six male, age range 20......-49 years) with a need for an occlusal dental restoration in two homologous teeth participated in the study, In this split-mouth design, the patient received the dental treatment wearing 3D video glasses and without video glasses (control situation) in a randomized order. The tooth cavities were prepared...... in accordance with conventional techniques after mounting the video glasses. The patient rated the intensity of pain and unpleasantness on 100 mm visual analogue scales (VASs) after preparation of the first cavity; immediately after, the opposite tooth was prepared and again the volunteer rated the intensity...

  3. Evaluation of efficacy of restorative dental treatment provided under general anesthesia at hospitalized pediatric dental patients of Isfahan

    Directory of Open Access Journals (Sweden)

    Alireza Eshghi

    2012-01-01

    Conclusion: Stainless steel crown restorations had significantly better results vs other posterior restorations. The failure rates of stainless steel crown and anterior composite resin build-up restorations did not correlate with the time of follow-up in comparison of other restorations.

  4. Effect of type of cavity preparation (bur,Er:YAG laser and restorative materials on prevention of caries lesion

    Directory of Open Access Journals (Sweden)

    Masumeh Hasani Tabatabaei

    2017-03-01

    Full Text Available Background and Aims: Despite the reduction of incidence of dental caries in recent years, this disease is common and many efforts were conducted to decrease the prevalence of dental caries. On the other hand secondary caries lesions are the main reason for replacement of direct restorations. Therefore, the aim of the current study was to evaluate suitable methods of preparation and restorative materials to reduce caries recurrence. Materials and Methods: In this experimental study, eighty human teeth were collected and stored in normal saline. The teeth were soft-tissue debrided and cleaned with water/pumice slurry and rubber cups in a low-speed handpiece. Speciments were randomly divided in two main groups. Cavities were prepared with diamond burs or Er:YAG laser (10 Hz, 300 mJ, 3W. Each group was divided into 4 sub-groups, and restored with a glass-ionomer cement (Fuji IX, resin modified glass-ionomer (Fuji II LC, total etch bonding + composite resin or self-etch bonding + composite resin. The specimens were submitted to pH cycling. Speciments were then sectioned, polished and Vickers microhardness measurements were performed on each specimen. Differences among the medians were analyzed using two way ANOVA test at a 95% confidence level and Tukey test. Results: Statistical analysis showed significant difference in the type of substrate (enamel, dentin in both main groups (P<0.0001 but no differences in the caries lesion development between the cavities restored with the same material and prepared with diamond burs or Er:YAG laser. Conclusion: The Er:YAG laser used for cavity preparation and different types of restorative materials used did not show the ability to guarantee significantly more acid-resistance tooth structure against demineralization.

  5. Experience with virtual reality-based technology in teaching restorative dental procedures.

    Science.gov (United States)

    Buchanan, Judith A

    2004-12-01

    This article reports on extensive experience with advanced simulation at the University of Pennsylvania, School of Dental Medicine (UPSDM). Virtual reality-based technology (VRBT) or advanced simulation is currently available for the instruction of dental students in preclinical restorative procedures. UPSDM was one of the first schools in the world to have extensive experience with VRBT technology using an advanced simulation unit (DentSim) from DenX, Ltd. UPSDM's experience consists of several years of research using control and experimental groups, employing students to participate in an investigative project, and using the units for remediation and a supplement to the preclinical laboratory. Currently, all first-year students (Class of 2007 and Class of 2008) are receiving most of their preparative operative training on the VRBT units. UPSDM started with one (beta) version unit in 1998, which was later updated and expanded first to four units and recently to fifteen units. This communication is presenting the studies that were of fundamental importance in making the decision to acquire fifteen units in 2003. The areas of main interest to the SDM concerning this technology were its use in teaching, refreshing, and remediating students in restorative procedures and its effectiveness as a teaching methodology in relation to time, efficiency, and faculty. Several studies with varying parameters were performed at various time points. The limited statistical analysis conducted was not conclusive for all measures, and in some cases the data only suggest areas of possible significance. This is due to the low number of students who could access the limited number of available units and the change of protocols in response to student and faculty input. Overall, the results do suggest, however, that students learn faster, arrive at the same level of performance, accomplish more practice procedures per hour, and request more evaluations per procedure or per hour than in our

  6. Information system analysis of an e-learning system used for dental restorations simulation.

    Science.gov (United States)

    Bogdan, Crenguţa M; Popovici, Dorin M

    2012-09-01

    The goal of using virtual and augmented reality technologies in therapeutic interventions simulation, in the fixed prosthodontics (VirDenT) project, is to increase the quality of the educational process in dental faculties, by assisting students in learning how to prepare teeth for all-ceramic restorations. Its main component is an e-learning virtual reality-based software system that will be used for the developing skills in grinding teeth, needed in all-ceramic restorations. The complexity of the domain problem that the software system dealt with made the analysis of the information system supported by VirDenT necessary. The analysis contains the following activities: identification and classification of the system stakeholders, description of the business processes, formulation of the business rules, and modelling of business objects. During this stage, we constructed the context diagram, the business use case diagram, the activity diagrams and the class diagram of the domain model. These models are useful for the further development of the software system that implements the VirDenT information system. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  7. Difference in opalescence of restorative materials by the illuminant.

    Science.gov (United States)

    Yu, Bin; Lee, Yong-Keun

    2009-08-01

    To determine the differences in the opalescence parameter (OP) of indirect and direct resin composites, veneer ceramics and bovine enamel relative to the CIE standard illuminants D65, A and F2. BelleGlass NG (indirect resin; 10 shades) and Estelite Sigma (direct resin; 12 shades), and 4 shades of veneer ceramics were investigated. Bovine enamel was used as a reference. Reflected and transmitted colors of specimens were measured relative to the illuminants D65, A and F2 with a reflection spectrophotometer. OP values relative to the three illuminants [OP(D65), OP(A) and OP(F2)], difference in OP (DeltaOP) and OP difference ratio relative to OP(D65) [DeltaOP/OP(D65)] by the change of illuminants were calculated. Within each restorative material, DeltaOP and DeltaOP/OP(D65) values were analyzed with two-way analysis of variance (ANOVA), with the fixed factors of the shade designation and the combination of illuminants (alpha=0.05). DeltaOP and DeltaOP/OP(D65) values were influenced by the two factors within each restorative material based on two-way ANOVA. High opalescent materials showed higher DeltaOP values. OP(D65) was lower than OP(F2) and OP(A) values. Restorative materials showed lower DeltaOP/OP(D65) values than bovine enamel. Correlation coefficients between OP values relative to different illuminants were higher than 0.961 (Popalescence properties as compared with natural tooth enamel.

  8. Dental Amalgam

    Science.gov (United States)

    ... Products and Medical Procedures Dental Devices Dental Amalgam Dental Amalgam Share Tweet Linkedin Pin it More sharing options Linkedin Pin it Email Print Dental amalgam is a dental filling material which is ...

  9. Behavioural and physiological outcomes of biofeedback therapy on dental anxiety of children undergoing restorations: a randomised controlled trial.

    Science.gov (United States)

    Dedeepya, P; Nuvvula, S; Kamatham, R; Nirmala, S V S G

    2014-04-01

    To explore the efficacy of biofeedback as possible alternative means of psychological behaviour guidance in children receiving dental restorations. Randomised clinical trial with a cross over design carried out on 40 children (19 boys and 21 girls) to determine the efficacy of biofeedback in reducing the dental anxiety through subjective and objective measures during restorative treatments under cotton roll isolation without administration of local analgesia. Highly anxious children with a minimum of five carious lesions were trained to lower their anxiety using biofeedback in five sessions within a 4-week interval, each session lasting for 45 min. After initial training, children were randomly divided into two groups and restorations were placed in four sequential therapeutic sessions with a 1-week interval and a follow-up visit 3 months later. First group received biofeedback in the second and third sessions; whereas the second group received biofeedback in the first and third sessions. Biofeedback therapy in children led to lower levels of anxiety in the initial appointments when assessed objectively, however the subjective methods of evaluation could not depict any statistically significant difference. Biofeedback can be used in the initial visits for dentally anxious children and the usage of simpler biofeedback machines for these appointments in dental setup is suggested.

  10. Novel surface coating materials for endodontic dental implant

    International Nuclear Information System (INIS)

    Fathi, M.H.; Mortazavi, V.; Moosavi, S.B.

    2003-01-01

    The aim of this study was to design and produce novel coating materials in order to obtain two goals including; improvement of the corrosion behavior of metallic dental endodontic implant and the bone osteointegration simultaneously. Stainless steel 316L (SS) was used as a metallic substrate and a novel Hydroxyapatite/Titanium (HA/Ti) composite coating was prepared on it. Structural characterization techniques including XRD, SEM and EDX were utilized to investigate the microstructure and morphology of the coating. Electrochemical tests were performed in physiological solutions in order to determine and compare the corrosion behavior of the coated and uncoated specimens as an indication of biocompatibility. Two types of endodontic implants including; SS with and without (HA/Ti) composite coating were prepared and subsequently implanted in the mandibular canine of 20 cats after completion of root canal treatment and osseous preparation. After a healing period of 4 months, osteointegration evaluation and histopathological interpretation was carried out using SEM and optical microscopy. Results indicate that the novel HA/Ti composite coating improves the corrosion behavior and biocompatibility of SS endodontic dental implant. The clinical evaluation (in vivo test) results showed that there was significant difference in osteointegration between coated and uncoated endodontic dental implants and average bone osteointegration of coated implants were more than uncoated implants. The histopathological results and bone tissue response to the coated implants was acceptable and it was concluded that HA/Ti composite coated SS could be used as well as an endodontic dental implant. (author)

  11. Artifacts by dental materials on magnetic resonance imaging

    International Nuclear Information System (INIS)

    Hong, Hyun Sook; Choi, Deuk Lin; Kim, Ki Jung; Suh, Won Hyuck

    1992-01-01

    Magnetic resonance imaging (MRI) has proved to be a valuable method for evaluation of the head and neck. Unfortunately, metallic devices associated with certain dental fillings and appliances often cause variable artifacts that can obscure normal or pathologic conditions on MR and computed tomography. In this work, we assessed the MR appearance of dental prosthetic materials in vitro and in vivo including precious alloys, nonprecions alloys, resin, amalgam and titanium alloy. For in vivo studies, these materials were placed in healthy volunteer's mouths and then images were assessed. Analysis of the appearance of shape and extent of artifact, and observed influence of these artifacts on the image interpretation at 0.2 Tesla permanent type MR scanner were valuated. Material used as temporary or permanent filling of crowns such as amalgam, precious alloy and, microfilled resin did not cause artifact on the image. The size of the artifact produced by the nonprecious alloys was influenced by the ferromagnetism of the object and the volume prosthesis, and was related to the scanning sequence. Nonprecious alloys produced minimal local signal distortion, where precious alloys, and dental resin had no effect on the MR images in vivo. These results were mainly from a low field strength MR scanner used in this study

  12. Analysis of microleakage of temporary restorative materials in primary teeth

    Directory of Open Access Journals (Sweden)

    Geórgia Linhares dos Santos

    2014-01-01

    Full Text Available Aim: The aim of this study was to compare the coronal microleakage of restorative materials used between sessions of endodontic treatment in primary teeth. Materials and Methods: Forty healthy primary canines were chosen and randomly allocated to four groups: Group 1 - Cimpat Branco ® (n = 10, Group 2 - Bioplic ® (n = 10, Group 3 - Maxxion R ® glass ionomer cement (n = 10, and Group 4 (control - Z350 ® composite resin (n = 10. Class V cavities were created and fillings carried out following the manufacturer′s instructions. The teeth were submitted to thermocycling, sealed, and immersed in 0.5% basic fuchsin solution for 24 h. The teeth were split along their long axis in the vestibulolingual direction and the tooth-restorative material interface was photographed. The percentage of microleakage was calculated using the ImageJ program. Data were analyzed using the analysis of variance (ANOVA F-test and Bonferroni′s t-test, with a 5% level of significance. Results: The following mean percentages of microleakage were found: Group 1 = 16.08%, Group 2 = 46.98%, Group 3 = 47.93%, and Group 4 = 11.03%. Statistically, significant differences were found in the comparison of Groups 1 and 4 to Groups 2 and 3. Conclusion: Cimpat Branco ® had a lower percentage of microleakage in comparison to Bioplic ® and Maxxion R ® glass ionomer cement.

  13. Wear measurement of dental tissues and materials in clinical studies: A systematic review.

    Science.gov (United States)

    Wulfman, C; Koenig, V; Mainjot, A K

    2018-06-01

    This study aims to systematically review the different methods used for wear measurement of dental tissues and materials in clinical studies, their relevance and reliability in terms of accuracy and precision, and the performance of the different steps of the workflow taken independently. An exhaustive search of clinical studies related to wear of dental tissues and materials reporting a quantitative measurement method was conducted. MedLine, Embase, Scopus, Cochrane Library and Web of Science databases were used. Prospective studies, pilot studies and case series (>10 patients), as long as they contained a description of wear measurement methodology. Only studies published after 1995 were considered. After duplicates' removal, 495 studies were identified, and 41 remained for quantitative analysis. Thirty-four described wear-measurement protocols, using digital profilometry and superimposition, whereas 7 used alternative protocols. A specific form was designed to analyze the risk of bias. The methods were described in terms of material analyzed; study design; device used for surface acquisition; matching software details and settings; type of analysis (vertical height-loss measurement vs volume loss measurement); type of area investigated (entire occlusal area or selective areas); and results. There is a need of standardization of clinical wear measurement. Current methods exhibit accuracy, which is not sufficient to monitor wear of restorative materials and tooth tissues. Their performance could be improved, notably limiting the use of replicas, using standardized calibration procedures and positive controls, optimizing the settings of scanners and matching softwares, and taking into account unusable data. Copyright © 2018 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.

  14. Advances in dental veneers: materials, applications, and techniques.

    Science.gov (United States)

    Pini, Núbia Pavesi; Aguiar, Flávio Henrique Baggio; Lima, Débora Alves Nunes Leite; Lovadino, José Roberto; Terada, Raquel Sano Suga; Pascotto, Renata Corrêa

    2012-01-01

    Laminate veneers are a conservative treatment of unaesthetic anterior teeth. The continued development of dental ceramics offers clinicians many options for creating highly aesthetic and functional porcelain veneers. This evolution of materials, ceramics, and adhesive systems permits improvement of the aesthetic of the smile and the self-esteem of the patient. Clinicians should understand the latest ceramic materials in order to be able to recommend them and their applications and techniques, and to ensure the success of the clinical case. The current literature was reviewed to search for the most important parameters determining the long-term success, correct application, and clinical limitations of porcelain veneers.

  15. Influence of the shape of the layers in photo-cured dental restorations on the shrinkage stress peaks-FEM study.

    Science.gov (United States)

    Kowalczyk, Piotr

    2009-12-01

    The aim of the paper is to analyse an influence of the shape of the layers in photo-cured dental restorations of Class I on distribution of shrinkage stresses along the tooth-restoration interface. The study is a continuation of the previous considerations (Kowalczyk and Gambin (2008) [1]), where techniques, which reduce stress concentration at the top of the tooth-restoration interface, were considered. The analysis leads to proposition of new layer forming techniques, which diminish the stress peaks at the interface and prevent the crack propagation process. To find the stress distributions in the dental restoration layers and the tooth tissues the finite element method implemented in the ABAQUS (Simulia, Providence, USA) software is used. For Class I restoration of the premolar tooth, the axisymmetrical model is assumed. The restoration is made of four layers of a photo-cured composite. Between the tooth tissues and the restoration, a layer of bonding agent 0.01mm thick is placed and modeled by FEM with help of the cohesive elements. The assumed model takes into account an influence of changes of elastic properties and viscous effects. For each case of the restoration layers system, the Huber-Mises stresses are analysed. The investigations show that the stresses near the restoration-tooth tissue interface are reduced due to viscous flow of the cured material and due to existence of a thin layer of the bonding agent. However, the stress distribution both, in the restoration and in the tooth tissues, is strongly dependent on a shape of the filling layers. Numerical simulations disclose that stress peaks are located at the top corners of each layer. The top corners of the last layer are the places where microleakage may occur. Stress concentrations at the corners of the preceding layers may lead to a growth of uprising crack. It will be shown that the flat layers in the restoration create relatively high values of the stress peaks. The rounded layers, with shapes

  16. Surface Characteristics and Biofilm Development on Selected Dental Ceramic Materials

    Directory of Open Access Journals (Sweden)

    Kyoung H. Kim

    2017-01-01

    Full Text Available Background. Intraoral adjustment and polishing of dental ceramics often affect their surface characteristics, promoting increased roughness and consequent biofilm growth. This study correlated surface roughness to biofilm development with four commercially available ceramic materials. Methods. Four ceramic materials (Vita Enamic®, Lava™ Ultimate, Vitablocs Mark II, and Wieland Reflex® were prepared as per manufacturer instructions. Seventeen specimens of each material were adjusted and polished to simulate clinical intraoral procedures and another seventeen remained unaltered. Specimens were analysed by SEM imaging, confocal microscopy, and crystal violet assay. Results. SEM images showed more irregular surface topography in adjusted specimens than their respective controls. Surface roughness (Ra values were greater in all materials following adjustments. All adjusted materials with the exception of Vitablocs Mark II promoted significantly greater biofilm growth relative to controls. Conclusion. Simulated intraoral polishing methods resulted in greater surface roughness and increased biofilm accumulation.

  17. Machine guides restoration by using a polymeric material

    Directory of Open Access Journals (Sweden)

    В. Б. Струтинський

    2015-11-01

    Full Text Available The restoration of slide rest guides of the automatic lathe PUB 130 was made by using a polymeric material in the laboratory, and the measurements of the rest displacement strength were made on a specially created experimental stand with the ADC and the PC and subsequent determination of the coefficient of friction. The performed experiments revealed that in the speed range of saddle feed from 0,0228 to 0,075 m/s, the coefficient of friction is within 0,047-0,055. At the same time, the transition to the low-feed (0,0005-0,0022 m/s results in to marked increase of the friction coefficient and the rest hopping movement. However, this phenomenon is likely due to the fact that elastic tie in the form of steel beam with tensometers was put into the feeder of the rest. This explanation let us hope that, with rigid connection of the drive and the rest such a phenomenon will not take place and the value of friction will not differ substantially from the friction obtained at high speeds. The obtained results make it possible to consider the use of a polymer material to be the optimal way to restore worn-out machines

  18. Special cluster issue on tribocorrosion of dental materials

    Science.gov (United States)

    Mathew, Mathew T.; Stack, Margaret M.

    2013-10-01

    Tribocorrosion affects all walks of life from oil and gas conversion to biomedical materials. Wear can interact with corrosion to enhance it or impede it; conversely, corrosion can enhance or impede wear. The understanding of the interactions between physical and chemical phenomena has been greatly assisted by electrochemical and microscopic techniques. In dentistry, it is well recognized that erosion due to dissolution (a term physicists use to denote wear) of enamel can result in tooth decay; however, the effects of the oral environment, i.e. pH levels, electrochemical potential and any interactions due to the forces involved in chewing are not well understood. This special cluster issue includes investigations on the fundamentals of wear-corrosion interactions involved in simulated oral environments, including candidate dental implant and veneer materials. The issue commences with a fundamental study of titanium implants and this is followed by an analysis of the behaviour of commonly used temporomandibular devices in a synovial fluid-like environment. The analysis of tribocorrosion mechanisms of Ti6Al4V biomedical alloys in artificial saliva with different pHs is addressed and is followed by a paper on fretting wear, on hydroxyapatite-titanium composites in simulated body fluid, supplemented with protein (bovine serum albumin). The effects of acid treatments on tooth enamel, and as a surface engineering technique for dental implants, are investigated in two further contributions. An analysis of the physiological parameters of intraoral wear is addressed; this is followed by a study of candidate dental materials in common beverages such as tea and coffee with varying acidity and viscosity and the use of wear maps to identify the safety zones for prediction of material degradation in such conditions. Hence, the special cluster issue consists of a range of tribocorrosion contributions involving many aspects of dental tribocorrosion, from analysis of physiological

  19. Crack tip fracture toughness of base glasses for dental restoration glass-ceramics using crack opening displacements.

    Science.gov (United States)

    Deubener, J; Höland, M; Höland, W; Janakiraman, N; Rheinberger, V M

    2011-10-01

    The critical stress intensity factor, also known as the crack tip toughness K(tip), was determined for three base glasses, which are used in the manufacture of glass-ceramics. The glasses included the base glass for a lithium disilicate glass-ceramic, the base glass for a fluoroapatite glass-ceramic and the base glass for a leucite glass-ceramic. These glass-ceramic are extensively used in the form of biomaterials in restorative dental medicine. The crack tip toughness was established by using crack opening displacement profiles under experimental conditions. The crack was produced by Vickers indentation. The crack tip toughness parameters determined for the three glass-ceramics differed quite significantly. The crack tip parameters of the lithium disilicate base glass and the leucite base glass were higher than that of the fluoroapatite base glass. This last material showed glass-in-glass phase separation. The discussion of the results clearly shows that the droplet glass phase is softer than the glass matrix. Therefore, the authors conclude that a direct relationship exists between the chemical nature of the glasses and the crack tip parameter. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Assessment of exposures and potential risks to the US adult population from the leaching of elements from gold and ceramic dental restorations.

    Science.gov (United States)

    Richardson, G Mark; James, Kyle Jordan; Peters, Rachel Elizabeth; Clemow, Scott Richard; Siciliano, Steven Douglas

    2016-01-01

    Using data from the 2001 to 2004 US National Health and Nutrition Examination Survey (NHANES) on the number and placement of tooth restorations in adults, we quantified daily doses due to leaching of elements from gold (Au) alloy and ceramic restorative materials. The elements with the greatest leaching rates from these materials are often the elements of lowest proportional composition. As a result, exposure due to wear will predominate for those elements of relatively high proportional composition, while exposure due leaching may predominate for elements of relatively low proportional composition. The exposure due to leaching of silver (Ag) and palladium (Pd) from Au alloys exceeded published reference exposure levels (RELs) for these elements when multiple full surface crowns were present. Six or more molar crowns would result in exceeding the REL for Ag, whereas three or more crowns would be necessary to exceed the REL for Pd. For platinum (Pt), the majority of tooth surfaces, beyond just molar crowns, would be necessary to exceed the REL for Pd. Exposures due to leaching of elements from ceramic dental materials were less than published RELs for all components examined here, including having all restorations composed of ceramic.

  1. In vitro color stability of provisional restorative materials

    Directory of Open Access Journals (Sweden)

    Hamid Jalali

    2012-01-01

    Aims: The purpose of this study was to investigate the effect of tea on provisional restorative materials. Setting and Design: This study was designed to measure the degree of color change of three acrylic resin provisional materials, before and after immersion in artificial saliva and artificial saliva-tea solution for 2 and 4 weeks. Materials and Methods : Three types of acrylic provisional materials (duralay, tempron, acropars TRP, were studied. Twenty disks (20±0.1 mm by 2±0.05 mm were fabricated from each material. Specimens were polished with acrylic bur using pumice and diamond polishing paste. Base line color was measured using a spectrophotometer. Ten disks were stored in artificial saliva and 10 were stored in a solution of artificial saliva and tea at room temperature. Color measurements were made after 2 and 4 weeks of immersion. Statistical analysis used: Differences in color changes were compared by two way ANOVA, across the six groups, followed by a Turkey-Kramer′s multiple comparison test. Results: For specimens immersed in artificial saliva, the color change of methyl methacrylate materials; duralay (ΔE=4.94 and tempron (ΔE=6.54, was significantly more than butyl methacrylate material; acropars (ΔE=4.10. After immersion in an artificial saliva- tea solution, tempron exhibited less color change (ΔE=8.50 compared to duralay (ΔE=10.93 and acropars (ΔE=15.64. Conclusion: Color stability of methyl methacrylate is higher than butyl methacrylates so if provisional materials are used for extended periods of time; tempron is preferred.

  2. Readability of pediatric health materials for preventive dental care

    Directory of Open Access Journals (Sweden)

    Riedy Christine A

    2006-11-01

    Full Text Available Abstract Background This study examined the content and general readability of pediatric oral health education materials for parents of young children. Methods Twenty-seven pediatric oral health pamphlets or brochures from commercial, government, industry, and private nonprofit sources were analyzed for general readability ("usability" according to several parameters: readability, (Flesch-Kincaid grade level, Flesch Reading Ease, and SMOG grade level; thoroughness, (inclusion of topics important to young childrens' oral health; textual framework (frequency of complex phrases, use of pictures, diagrams, and bulleted text within materials; and terminology (frequency of difficult words and dental jargon. Results Readability of the written texts ranged from 2nd to 9th grade. The average Flesch-Kincaid grade level for government publications was equivalent to a grade 4 reading level (4.73, range, 2.4 – 6.6; F-K grade levels for commercial publications averaged 8.1 (range, 6.9 – 8.9; and industry published materials read at an average Flesch-Kincaid grade level of 7.4 (range, 4.7 – 9.3. SMOG readability analysis, based on a count of polysyllabic words, consistently rated materials 2 to 3 grade levels higher than did the Flesch-Kincaid analysis. Government sources were significantly lower compared to commercial and industry sources for Flesch-Kincaid grade level and SMOG readability analysis. Content analysis found materials from commercial and industry sources more complex than government-sponsored publications, whereas commercial sources were more thorough in coverage of pediatric oral health topics. Different materials frequently contained conflicting information. Conclusion Pediatric oral health care materials are readily available, yet their quality and readability vary widely. In general, government publications are more readable than their commercial and industry counterparts. The criteria for usability and results of the analyses

  3. Effects of audiovisual distraction in children with special healthcare needs during dental restorations: a randomized crossover clinical trial.

    Science.gov (United States)

    Bagattoni, Simone; D'Alessandro, Giovanni; Sadotti, Agnese; Alkhamis, Nadia; Piana, Gabriela

    2018-01-01

    Audiovisual distraction using video eyeglasses is useful in managing distress and reducing fear and anxiety in healthy children during dental treatments. To evaluate the effect of audiovisual distraction on behavior and self-reported pain of children with special healthcare needs (SHCN) without intellectual disability during dental restorations and its influence on the operator stress and the time of the appointment. This randomized controlled crossover trial comprised 48 children with SHCN requiring at least two dental restorations. One restoration was done wearing the video eyeglasses and one wearing conventional behavior management techniques. Subjective and objective pain was evaluated using the Faces Pain Scale - Revised (FPS-R) and the revised Face, Leg, Activity, Cry, and Consolability scale (r-FLACC). The operator stress using a VAS, the time of the appointment, and the child satisfaction were recorded. The use of video eyeglasses significantly reduced the operator stress. The bivariate analysis showed that the mean FPS-R score and the mean r-FLACC score were significantly lower using the video eyeglasses only during the second clinical session. Audiovisual distraction could be useful in managing distress in SHCN children without intellectual disability but cannot replace the conventional behavior management techniques. © 2017 BSPD, IAPD and John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. [The effects of topical fluoridation of Ketac Molar Aplicap glass-ionomer material on the growth of cariogenic bacteria contained in the dental plaque].

    Science.gov (United States)

    Płuciennik-Stronias, Małgorzata; Zarzycka, Beata; Bołtacz-Rzepkowska, Elzbieta

    2013-01-01

    Dental caries is a bacterial disease. The most important element used in caries prevention is fluoride, which is derived from the air, diet or fluoride-containing preparations and materials, e.g. glass-ionomer restorations. Modern fluoride-containing restorative materials are capable of releasing fluoride to the environment. Fluoride can be also accumulated in glass-ionomer cements, thus an attempt was made to saturate these materials with fluoride. The aim of the study was to evaluate the effect of topical fluoridation of Ketac Molar Aplicap glass-ionomer cement on the growth of Lactobacillus spp. in the dental plaque. The study was carried out in 15 patients with good oral hygiene, in whom 35 fillings with conventional glass-ionomer material, Ketac Molar Aplicap, were performed. After 6 months, three-day dental plaque from these fillings was examined. Next, fluoride was rubbed on the glass-ionomer surface and the examination of three-day dental plaque was repeated. No statistically significant differences (p = 0.143) in the amounts of Lactobacillus spp. in the plaque collected prior to and after topical fluoridation were revealed. Fluoride rubbed in the conventional glass-ionomer cement, Ketac Molar Aplicap, did not affect the amount of Lactobacillus spp. in the dental plaque growing on this material.

  5. Influence of citric acid on the surface texture of glass ionomer restorative materials

    OpenAIRE

    Reddy, Dappili Swami Ranga; Kumar, Ramachandran Anil; Venkatesan, Sokkalingam Mothilal; Narayan, Gopal Shankar; Duraivel, Dasarathan; Indra, Rajamani

    2014-01-01

    Aim: This study determined the effectiveness of G-coat plus surface protective agent over petroleum jelly on the surface texture of conventional Glass ionomer restorative materials. Materials and Methods: Three chemically cured conventional glass ionomer restorative materials type II, type IX and ketac molar were evaluated in this study. Sixty specimens were made for each restorative material. They were divided into two groups of thirty specimens each. Of the sixty specimens, thirty were...

  6. Updating Classifications of Ceramic Dental Materials: A Guide to Material Selection.

    Science.gov (United States)

    McLaren, Edward A; Figueira, Johan

    2015-06-01

    The indications for and composition of today's dental ceramic materials serve as the basis for determining the appropriate class of ceramics to use for a given case. By understanding the classifications, composition, and characteristics of the latest all-ceramic materials, which are presented in this article in order of most to least conservative, dentists and laboratory technicians can best determine the ideal material for a particular treatment.

  7. Radiopacity of restorative materials using digital images Radiopacidade de materiais restauradores utilizando imagens digitais

    Directory of Open Access Journals (Sweden)

    Leda Maria Pescinini Salzedas

    2006-04-01

    Full Text Available The radiopacity of esthetic restorative materials has been established as an important requirement, improving the radiographic diagnosis. The aim of this study was to evaluate the radiopacity of six restorative materials using a direct digital image system, comparing them to the dental tissues (enamel-dentin, expressed as equivalent thickness of aluminum (millimeters of aluminum. Five specimens of each material were made. Three 2-mm thick longitudinal sections were cut from an intact extracted permanent molar tooth (including enamel and dentin. An aluminum step wedge with 9 steps was used. The samples of different materials were placed on a phosphor plate together with a tooth section, aluminum step wedge and metal code letter, and were exposed using a dental x-ray unit. Five measurements of radiographic density were obtained from each image of each item assessed (restorative material, enamel, dentin, each step of the aluminum step wedge and the mean of these values was calculated. Radiopacity values were subsequently calculated as equivalents of aluminum thickness. Analysis of variance (ANOVA indicated significant differences in radiopacity values among the materials (PA radiopacidade dos materiais tem sido valorizada como importante requisito, incrementando o diagnóstico radiográfico. O objetivo deste estudo foi avaliar, no sistema digital Digora, as densidades radiográficas de 06 materiais restauradores comparando-os aos tecidos dentais (esmalte e dentina, expressos em milímetros de alumínio (mm Al. Foram confeccionadas 05 amostras de cada material e três cortes de um molar extraído hígido (incluindo esmalte e dentina, com 2 mm de espessura, e um penetrômetro de alumínio com 09 degraus. Sobre cada placa óptica foram colocados amostras dos diferentes materiais, um corte do dente humano, o penetrômetro e a identificação, e feita a exposição utilizando um aparelho de raios X. Foram obtidas 05 medidas de densidade radiográfica de

  8. Teaching atraumatic restorative treatment in U.S. dental schools: a survey of predoctoral pediatric dentistry program directors.

    Science.gov (United States)

    Kateeb, Elham T; Warren, John J; Damiano, Peter; Momany, Elizabeth; Kanellis, Michael; Weber-Gasparoni, Karin; Ansley, Tim

    2013-10-01

    The International Dental Federation and World Health Organization have promoted the use of Atraumatic Restorative Treatment (ART) in modern clinical settings worldwide. In the United States, the practice of ART is not believed to be widely used, which may be a result of little attention given to ART training in predoctoral pediatric dentistry curricula in U.S. dental schools. This study investigated the extent of clinical and didactic instruction on ART provided in U.S. dental schools by surveying the predoctoral pediatric dentistry programs in 2010. Of the fifty-seven directors asked to complete the survey, forty-four responded for a response rate of 77 percent. Of these forty-four programs, 66 percent reported providing clinical training on ART, though only 14 percent provide this training often or very often. The types of ART training provided often or very often included interim treatment (18 percent) and single-surface cavities (14 percent) in primary teeth. However, ART was said to be rarely taught as a definitive treatment in permanent teeth (2 percent). Attitude was a major predictor, for clinical training provided and using professional guidelines in treatment decisions were associated with a positive attitude towards ART. These predoctoral pediatric dentistry programs used ART mainly in primary, anterior, and single-surface cavities and as interim treatment. As ART increases access of children to dental care, the incorporation of the ART approach into the curricula of U.S. dental schools should be facilitated by professional organizations.

  9. Mechanical properties of polymer-infiltrated-ceramic (sodium aluminum silicate) composites for dental restoration.

    Science.gov (United States)

    Cui, Bencang; Li, Jing; Wang, Huining; Lin, Yuanhua; Shen, Yang; Li, Ming; Deng, Xuliang; Nan, Cewen

    2017-07-01

    To fabricate indirect restorative composites for CAD/CAM applications and evaluate the mechanical properties. Polymer-infiltrated-ceramic composites were prepared through infiltrating polymer into partially sintered sodium aluminum silicate ceramic blocks and curing. The corresponding samples were fabricated according to standard ISO-4049 using for mechanical properties measurement. The flexural strength and fracture toughness were measured using a mechanical property testing machine. The Vickers hardness and elastic modulus were calculated from the results of nano-indentation. The microstructures were investigated using secondary electron detector. The density of the porous ceramic blocks was obtained through TG-DTA. The conversion degrees were calculated from the results of mid-infrared spectroscopy. The obtained polymer infiltrated composites have a maximum flexural strength value of 214±6.5MPa, Vickers hardness of 1.76-2.30GPa, elastic modulus of 22.63-27.31GPa, fracture toughness of 1.76-2.35MPam 1/2 and brittleness index of 0.75-1.32μm -1/2 . These results were compared with those of commercial CAD/CAM blocks. Our results suggest that these materials with good mechanical properties are comparable to two commercial CAD/CAM blocks. The sintering temperature could dramatically influence the mechanical properties. Restorative composites with superior mechanical properties were produced. These materials mimic the properties of natural dentin and could be a promising candidate for CAD/CAM applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. In vitro comparative evaluation of mechanical properties of temporary restorative materials used in fixed partial denture

    OpenAIRE

    Saisadan, D.; Manimaran, P.; Meenapriya, P. K.

    2016-01-01

    Introduction: Materials used to fabricate provisional restorations can be classified as acrylics or resin composites. Provisional crows can be either prefabricated or custom made. Acrylics: These materials have been used to fabricate provisional restorations since the 1930s and usually available as powder and liquid. They are the most commonly used materials today for both single-unit and multiple-unit restorations. In general, their popularity is due to their low cost, acceptable esthetics, ...

  11. Effect of dual-cure composite resin as restorative material on marginal adaptation of class 2 restorations.

    Science.gov (United States)

    Bortolotto, Tissiana; Melian, Karla; Krejci, Ivo

    2013-10-01

    The present study attempted to find a simple direct adhesive restorative technique for the restoration of Class 2 cavities. A self-etch adhesive system with a dual-cured core buildup composite resin (paste 1 + paste 2) was evaluated in its ability to restore proximo-occlusal cavities with margins located on enamel and dentin. The groups were: A, cavity filling (cf) with paste 1 (light-curing component) by using a layering technique; B, cf by mixing both pastes, bulk insertion, and dual curing; and C, cf by mixing both pastes, bulk insertion, and chemical curing. Two control groups (D, negative, bulk; and E, positive, layering technique) were included by restoring cavities with a classic three-step etch-and-rinse adhesive and a universal restorative composite resin. SEM margin analysis was performed before and after thermomechanical loading in a chewing simulator. Percentages (mean ± SD) of "continuous margins" were improved by applying the material in bulk and letting it self cure (54 ± 6) or dual cure (59 ± 9), and no significant differences were observed between these two groups and the positive control (44 ± 19). The present study showed that the dual-cured composite resin tested has the potential to be used as bulk filling material for Class 2 restorations. When used as filling materials, dual-cure composite resins placed in bulk can provide marginal adaptation similar to light-cured composites applied with a complex stratification technique.

  12. A rare allergy to a polyether dental impression material.

    Science.gov (United States)

    Mittermüller, Pauline; Szeimies, Rolf-Markus; Landthaler, Michael; Schmalz, Gottfried

    2012-08-01

    Polyether impression materials have been used in dentistry for more than 40 years. Allergic reactions to these materials such as reported in the 1970s ceased after replacement of a catalyst. Very recently, however, patients have started to report symptoms that suggest a new allergic reaction from polyether impression materials. Here, we report on the results of allergy testing with polyether impression materials as well as with its components. Eight patients with clinical symptoms of a contact allergy (swelling, redness or blisters) after exposure to a polyether impression material were subjected to patch tests, two of them additionally to a prick test. A further patient with atypical symptoms of an allergy (nausea and vomiting after contact with a polyether impression material in the oral cavity) but with a history of other allergic reaction was also patch tested. The prick tests showed no immediate reactions in the two patients tested. In the patch tests, all eight patients with typical clinical symptoms showed positive reactions to the mixed polyether impression materials, to the base paste or to a base paste component. The patient with the atypical clinical symptoms did not show any positive patch test reactions. Polyether impression materials may evoke type IV allergic reactions. The causative agent was a component of the base paste. In consideration of the widespread use of this impression material (millions of applications per year) and in comparison to the number of adverse reactions from other dental materials, the number of such allergic reactions is very low. In very scarce cases, positive allergic reactions to polyether impression materials are possible.

  13. Effect of a self-adhesive coating on the load-bearing capacity of tooth-coloured restorative materials.

    Science.gov (United States)

    Bagheri, R; Palamara, Jea; Mese, A; Manton, D J

    2017-03-01

    The aim of this study was to compare the flexural strength and Vickers hardness of tooth-coloured restorative materials with and without applying a self-adhesive coating for up to 6 months. Specimens were prepared from three resin composites (RC), two resin-modified glass-ionomer cements (RM-GIC) and two conventional glass-ionomer cements (CGIC). All materials were tested both with and without applying G-Coat Plus (GCP). Specimens were conditioned in 37 °C distilled deionized water for 24 h, and 1, 3 and 6 months. The specimens were strength tested using a four-point bend test jig in a universal testing machine. The broken specimen's halves were used for Vickers hardness testing. Representative specimens were examined under an environmental scanning electron microscope. Data analysis showed that regardless of time and materials, generally the surface coating was associated with a significant increase in the flexural strength of the materials. Applying the GCP decreased the hardness of almost all materials significantly (P < 0.05) and effect of time intervals on hardness was material dependent. The load-bearing capacity of the restorative materials was affected by applying self-adhesive coating and ageing. The CGIC had significantly higher hardness but lower flexural strength than the RM-GIC and RC. © 2016 Australian Dental Association.

  14. Biological evaluation of dental materials, in vitro and in vivo

    International Nuclear Information System (INIS)

    Kawahara, H.

    1982-01-01

    In this paper, the correlation between the user of tissue culture for in vitro tests and the tissue irritability and pupal response observed in in vitro tests, will be discussed. It would produce confusion if dental materials were standardised with the unreliable parameter of the living system in dynamic balance. Biological tests, both in vitro and in vivo, should be used for pre-standards testing, without any political control to establish physicochemical standards. As a first step, corrosion tests and the dissolution dosje of toxic components from the material in the tissue culture medium and/or artificial salvia should be standardised under conditions simulating the oral environment. The CNC method and photo-pattern analysis are used for the interpretation of cytotoxicity. The need for biological testing, both in vitro and in vivo, definitely exists in order to obtain physicochemical standards, with a biological simulation depending upon the feedback obtained from the results of in vitro and in vivo tests

  15. Esthetic smile rehabilitation of anterior teeth by treatment with biomimetic restorative materials: a case report

    Directory of Open Access Journals (Sweden)

    Gouveia TH

    2017-05-01

    Full Text Available Thayla Hellen Nunes Gouveia, Jéssica Dias Theobaldo, Waldemir Francisco Vieira-Junior, Débora Alves Nunes Leite Lima, Flávio Henrique Baggio Aguiar Department of Restorative Dentistry, Piracicaba Dental School, University of Campinas, Campinas, SP, Brazil Background: In daily clinical practice, esthetics of anterior teeth is a common presenting complaint of patients.Objective: This case report discusses the management of asymmetric smile associated with unsatisfactory extensive composite restorations and describes a clinical protocol using the direct composite resin for smile enhancement to restore the dental harmony of anterior teeth.Methods: The treatment planning was based on a diagnostic wax-up and cosmetic mock-up. After clinical and patient approvals were obtained, the patient was subjected to direct and indirect restorative treatment.Conclusion: Nanocomposites are an effective alternative for anterior teeth restorations. Additionally, good planning enables satisfactory esthetic results, leading to the correction of an inappropriate axial inclination of incisors. Keywords: composite, adhesive, smile, esthetic, restoration

  16. Determining the complex modulus of alginate irreversible hydrocolloid dental material.

    Science.gov (United States)

    King, Shalinie; See, Howard; Thomas, Graham; Swain, Michael

    2008-11-01

    The aim of the study is to investigate the visco-elastic response of an alginate irreversible hydrocolloid dental impression material during setting. A novel squeeze film Micro-Fourier Rheometer (MFR, GBC Scientific Equipment, Australia) was used to determine the complex modulus of an alginate irreversible hydrocolloid dental impression material (Algident, ISO 1563 Class A Type 1, Dentalfarm Australia Pty. Ltd.) during setting after mixing. Data was collected every 30s for 10 min in one study and every 10 min for a total of 60 min in another study. A high level of repeatability was observed. The results indicate that the MFR is capable of recording the complex shear modulus of alginate irreversible hydrocolloid for 60 min from the start of mixing and to simultaneously report the changing visco-elastic parameters at all frequencies between 1 Hz and 100 Hz. The storage modulus shows a dramatic increase to 370% of its starting value after 6 min and then reduces to 55% after 60 min. The loss modulus increases to a maximum of 175% of its starting value after 10 min and then reduces to 94% after 60 min. The MFR enables the changes in the complex modulus through the complete setting process to be followed. It is anticipated this approach may provide a better method to compare the visco-elastic properties of impression materials and assist with identification of optimum types for different clinical requirements. The high stiffness of the instrument and the use of band-limited pseudo-random noise as the input signal are the main advantages of this technique over conventional rheometers for determining the changes in alginate visco-elasticity.

  17. The Mechanical Behaviors of Various Dental Implant Materials under Fatigue

    Directory of Open Access Journals (Sweden)

    Fatma Bayata

    2018-01-01

    Full Text Available The selection of materials has a considerable role on long-term stability of implants. The materials having high resistance to fatigue are required for dental implant applications since these implants are subjected to cyclic loads during chewing. This study evaluates the performance of different types of materials (AISI 316L stainless steel, alumina and its porous state, CoCr alloys, yttrium-stabilized zirconia (YSZ, zirconia-toughened alumina (ZTA, and cp Ti with the nanotubular TiO2 surface by finite element analysis (FEA under real cyclic biting loads and researches the optimum material for implant applications. For the analysis, the implant design generated by our group was utilized. The mechanical behavior and the life of the implant under biting loads were estimated based on the material and surface properties. According to the condition based on ISO 14801, the FEA results showed that the equivalent von Mises stress values were in the range of 226.95 MPa and 239.05 MPa. The penetration analysis was also performed, and the calculated penetration of the models onto the bone structure ranged between 0.0037389 mm and 0.013626 mm. L-605 CoCr alloy-assigned implant model showed the least penetration, while cp Ti with the nanotubular TiO2 surface led to the most one. However, the difference was about 0.01 mm, and it may not be evaluated as a distinct difference. As the final numerical evaluation item, the fatigue life was executed, and the results were achieved in the range of 4 × 105 and 1 × 109 cycles. These results indicated that different materials showed good performance for each evaluation component, but considering the overall mechanical performance and the treatment process (implant adsorption by means of surface properties, cp Ti with the nanotubular TiO2 surface material was evaluated as the suitable one, and it may also be implied that it displayed enough performance in the designed dental implant model.

  18. The influence of location of local anesthesia and complexity/duration of restorative treatment on children's behavior during dental treatment.

    Science.gov (United States)

    Davidovich, Esti; Wated, Alham; Shapira, Joseph; Ram, Diana

    2013-01-01

    The purpose of this study was to investigate whether the region of local anesthetic injection and the complexity and duration of restorative treatment were associated with children's behavior during and immediately after dental treatment. This study examined 90 children, divided into two age groups (2-3.5 years old and >3.5-5.5 years old), who underwent dental treatment while lightly sedated. The region of local anesthesia (maxillary infiltration or mandibular block), complexity and duration of treatment, and behavior during and after treatment were assessed. Children's behavior during and after dental treatment, within and between age groups, was not found to be associated with the region of local anesthesia or complexity of treatment. For both age groups, more children exhibited negative behaviors during treatment when procedures exceeded 30 minutes. For younger children, more negative behaviors were also observed after longer vs shorter procedures. Treatment duration, not the region of local anesthesia or complexity of treatment, was associated with children's behavior during and after dental procedures.

  19. A survey of U.S. prosthodontists and dental schools on the current materials and methods for final impressions for complete denture prosthodontics.

    Science.gov (United States)

    Petrie, Cynthia S; Walker, Mary P; Williams, Karen

    2005-12-01

    The purpose of this study was to survey members of The American College of Prosthodontists (ACP) to evaluate current materials and methods for final impressions for complete denture prosthodontics in the United States. In addition, those methods were compared with methods and materials taught in U.S. dental schools via a second survey sent to the chairpersons of prosthodontic/restorative departments. An anonymous questionnaire was mailed to all 1762 active ACP members in the United States in 2003. A slightly modified questionnaire was also distributed to chairpersons of prosthodontic/restorative departments in the 54 U.S. dental schools. Data analysis was performed via frequency distribution and chi-square statistics. Nine hundred and forty-five questionnaires were returned by members of the ACP (54% return rate) and 42 questionnaires were returned by the U.S. dental schools (78% return rate). The majority of the reporting prosthodontists (88%) and dental schools (98%) use a border-molded custom tray for final impressions for complete denture prosthodontics. The most popular material for border molding was plastic modeling compound (67% of reporting ACP members, and 95% of the responding dental schools). Variability of the materials used for final impressions was observed, with the most popular materials being polyvinylsiloxane for the ACP members (36%) and polysulfide for the dental schools (64%). Statistically significant differences were found in the materials used for border molding by prosthodontists based on the time elapsed since completion of prosthodontic training. No differences were found in the materials used for impression of edentulous arches based on years of experience. Geographic location did not influence the materials and methods used by prosthodontists for complete denture final impressions. There was variability of the materials and techniques used for final impressions by ACP members and dental schools; however, overall there was an agreement

  20. Restoring proximal caries lesions conservatively with tunnel restorations

    Directory of Open Access Journals (Sweden)

    Chu CH

    2013-07-01

    Full Text Available Chun-Hung Chu1, May L Mei,1 Chloe Cheung,1 Romesh P Nalliah2 1Faculty of Dentistry, The University of Hong Kong, Hong Kong, People's Republic of China; 2Department of Restorative Dentistry and Biomaterials Sciences, Harvard School of Dental Medicine, Boston, MA, USA Abstract: The tunnel restoration has been suggested as a conservative alternative to the conventional box preparation for treating proximal caries. The main advantage of tunnel restoration over the conventional box or slot preparation includes being more conservative and increasing tooth integrity and strength by preserving the marginal ridge. However, tunnel restoration is technique-sensitive and can be particularly challenging for inexperienced restorative dentists. Recent advances in technology, such as the contemporary design of dental handpieces with advanced light-emitting diode (LED and handheld comfort, offer operative dentists better vision, illumination, and maneuverability. The use of magnifying loupes also enhances the visibility of the preparation. The advent of digital radiographic imaging has improved dental imaging and reduced radiation. The new generation of restorative materials has improved mechanical properties. Tunnel restoration can be an option to restore proximal caries if the dentist performs proper case selection and pays attention to the details of the restorative procedures. This paper describes the clinical technique of tunnel restoration and reviews the studies of tunnel restorations. Keywords: operative, practice, tunnel preparation, composite, amalgam, glass ionomer

  1. Direct restorative treatment of dental erosion caused by gastroesophageal reflux disease associated with bruxism: a case report.

    Science.gov (United States)

    Vidal, Cristina de Mattos Pimenta; Catelan, Anderson; Briso, André Luiz Fraga; dos Santos, Paulo Henrique

    2011-09-01

    Gastroesophageal reflux disease (GERD) is a gastrointestinal disorder in which stomach acids are chronically regurgitated into the esophagus and oral cavity. Continual exposure of the teeth to these acids can cause severe tooth wear. Dentists are often the first healthcare professionals to diagnose dental erosion in patients with GERD. This article presents a case report of a 27-year-old male smoker with tooth wear and dentin sensitivity caused by GERD associated with bruxism. After diagnosis, a multidisciplinary treatment plan was established. The initial treatment approach consisted of medical follow-up with counseling on dietary and smoking habits, as well as management of the gastric disorders with medication. GERD management and the dental treatment performed for the eroded dentition are described, including diagnosis, treatment planning, and restorative therapy.

  2. Cytotoxicity of Light-Cured Dental Materials according to Different Sample Preparation Methods

    Directory of Open Access Journals (Sweden)

    Myung-Jin Lee

    2017-03-01

    Full Text Available Dental light-cured resins can undergo different degrees of polymerization when applied in vivo. When polymerization is incomplete, toxic monomers may be released into the oral cavity. The present study assessed the cytotoxicity of different materials, using sample preparation methods that mirror clinical conditions. Composite and bonding resins were used and divided into four groups according to sample preparation method: uncured; directly cured samples, which were cured after being placed on solidified agar; post-cured samples were polymerized before being placed on agar; and “removed unreacted layer” samples had their oxygen-inhibition layer removed after polymerization. Cytotoxicity was evaluated using an agar diffusion test, MTT assay, and confocal microscopy. Uncured samples were the most cytotoxic, while removed unreacted layer samples were the least cytotoxic (p < 0.05. In the MTT assay, cell viability increased significantly in every group as the concentration of the extracts decreased (p < 0.05. Extracts from post-cured and removed unreacted layer samples of bonding resin were less toxic than post-cured and removed unreacted layer samples of composite resin. Removal of the oxygen-inhibition layer resulted in the lowest cytotoxicity. Clinicians should remove unreacted monomers on the resin surface immediately after restoring teeth with light-curing resin to improve the restoration biocompatibility.

  3. Longevity of dental amalgam in comparison to composite materials

    Directory of Open Access Journals (Sweden)

    Windisch, Friederike

    2008-11-01

    fillings in posterior teeth is difficult. Apart from the difficulties in conducting a randomized, controlled long-term study comparing the longevity of direct fillings, the fact that composites and adhesives used in a study have often already been replaced by the next generation of the product at the time of study publication presents an additional problem. Not only the filling material, but also patient parameters and local, intraoral factors (e. g. localisation of the filling as well as the treating dentist have an impact on the longevity of dental fillings. In evaluating economic studies, one has to refer to the heterogeneity of data on longevity in the medical evaluation. The only effect parameter used in the studies is longevity, other aspects (e. g. long-term functionality are only referred to in discussions. Extensive counselling of patients regarding the selection of the appropriate filling material is important. Conclusions: Amalgam fillings show a longer longevity than composite fillings. Two out of six systematic reviews conclude that the expected survival time of composite fillings can be comparable to amalgam fillings. However, these conclusions are based on the results of short-term studies which usually overestimate the longevity of filling materials. From an economic standpoint, amalgam is the more economic filling material compared to direct composite fillings in posterior teeth when considering longevity as the only result parameter. Other aspects than longevity need to be considered in individually choosing the appropriate dental filling material. For future studies aiming to compare the longevity of amalgam and composite fillings, a sufficient sample size and study period, preferably in the setting of a private dental practice, should be aimed for. An evaluation of the cost-effectiveness of amalgam and composite fillings should take the functionality of teeth over a longer time period into account, as well as patients’ preferences. The rapid

  4. Effect of the video output of the dental operating microscope on anxiety levels in a pediatric population during restorative procedures.

    Science.gov (United States)

    Sayed, Abrar; Ranna, Vinisha; Padawe, Dimple; Takate, Vilas

    2016-01-01

    Adapting a child to the alien settings of a dental operatory is a major challenge to the dentist. Fear of the unknown and preconceived notions of dental pain causes anxiety in the pediatric patient. This often leads to disruptive and uncooperative behavior in the dental operatory. Many methods of behavior management have been described, of which the Tell-Show-Do (TSD) is an established and time-tested technique of behavior management. To determine if a live visual output of the dental operating microscope (DOM) could be used as an adjunct to the TSD technique, to involve the child more completely in the procedure and reduce the fear of the unknown. The study was a randomized, controlled, crossover, and cross-sectional clinical trial. Data were obtained from two visits. 90 children having carious lesions on both lower first molars, in the 7-9 years age group were selected and divided randomly into two groups. Restorative procedures were performed on one tooth per visit, with visits 1 week apart. Live display of the procedure was shown to the patient using video output of the DOM displayed on a 72 inch LCD monitor, angled for best visibility of the child. Anxiety levels were evaluated using Venhams picture selection test and pulse oximetry. Student's t-test was used to compare the anxiety scores obtained from the two groups. The results showed there was a decrease in the anxiety from the first visit to the second visit. (P = 0.05 for Group A and P = 0.003 for Group B). The patients preferred the visit in which the DOM was used. The operator reported an increased patient compliance and reduced patient movement in the visits in which the DOM was used. There is a reduction in anxiety from the first visit to the second visit for restorative treatment when the DOM is used.

  5. Longevity of posterior resin composite restorations in permanent teeth in Public Dental Health Service

    DEFF Research Database (Denmark)

    Pallesen, Ulla; van Dijken, Jan W V; Halken, Jette

    2013-01-01

    To investigate in a prospective follow up the longevity of posterior resin composites (RC) placed in permanent teeth of children and adolescents attending Public Dental Health Service.......To investigate in a prospective follow up the longevity of posterior resin composites (RC) placed in permanent teeth of children and adolescents attending Public Dental Health Service....

  6. About Dental Amalgam Fillings

    Science.gov (United States)

    ... and Medical Procedures Dental Devices Dental Amalgam About Dental Amalgam Fillings Share Tweet Linkedin Pin it More ... should I have my fillings removed? What is dental amalgam? Dental amalgam is a dental filling material ...

  7. Restorative treatment thresholds for occlusal primary caries among dentists in the dental practice-based research network

    DEFF Research Database (Denmark)

    Gordan, Valeria V; Bader, James D; Garvan, Cynthia W

    2010-01-01

    : The investigators surveyed dentists enrolled in a dental practice-based research network who reported performing at least some restorative dentistry. In the survey, dentists were asked to indicate whether they would intervene surgically in a series of cases involving occlusal caries. Each case presentation included...... a photograph of an occlusal surface displaying typical characteristics of caries penetration and a written description of a patient at a specific level of risk of developing caries. Using logistic regression, the authors analyzed associations between surgical treatment with dentists' and practices......' characteristics and patients' caries risk levels. RESULTS: A total of 517 DPBRN practitioner-investigators responded to the questionnaire. Sixty-three percent of the respondents (326 of 517) indicated that in patients at low risk of developing caries, they would surgically restore teeth with lesions located...

  8. The Relative Patient Costs and Availability of Dental Services, Materials and Equipment in Public Oral Care Facilities in Tanzania.

    OpenAIRE

    Nyamuryekung'e, Kasusu K; Lahti, Satu M; Tuominen, Risto J

    2015-01-01

    Background Patient charges and availability of dental services influence utilization of dental services. There is little available information on the cost of dental services and availability of materials and equipment in public dental facilities in Africa. This study aimed to determine the relative cost and availability of dental services, materials and equipment in public oral care facilities in Tanzania. The local factors affecting availability were also studied. Methods A survey of all dis...

  9. Mechanical properties of resin-ceramic CAD/CAM restorative materials.

    Science.gov (United States)

    Awada, Abdallah; Nathanson, Dan

    2015-10-01

    The recent development of polymer-based computer-aided design and computer-aided manufactured (CAD/CAM) milling blocks and the limited availability of independent studies on these materials make it pertinent to evaluate their properties and identify potential strengths and limitations. The purpose of this in vitro study was to determine and compare mechanical properties (flexural strength, flexural modulus, modulus of resilience) and compare the margin edge quality of recently introduced polymer-based CAD/CAM materials with some of their commercially available composite resin and ceramic counterparts. The materials studied were Lava Ultimate Restorative (LVU; 3M ESPE), Enamic (ENA; Vita Zahnfabrik), Cerasmart (CES; GC Dental Products), IPS Empress CAD (EMP; Ivoclar Vivadent AG), Vitablocs Mark II (VM2; Vita Zahnfabrik), and Paradigm MZ100 Block (MZ1; 3M ESPE). Polished 4×1×13.5 mm bars (n=25) were prepared from standard-sized milling blocks of each tested material. The bars were subjected to a 3-point flexural test on a 10-mm span with a crosshead speed of 0.5 mm/min. In addition, 42 conventional monolithic crowns (7 per material) were milled. Margin edge quality was observed by means of macrophotography and optical microscopy, providing a qualitative visual assessment and a measurement of existing roughness. The results were analyzed by ANOVA followed by the Tukey HSD test (α=.05). The mean flexural strength of the tested materials ranged from 105 ±9 MPa (VM2) to 219 ±20 MPa (CES). The mean flexural modulus ranged from 8 ±0.25 GPa (CES) to 32 ±1.9 GPa (EMP). The mean modulus of resilience ranged from 0.21 ±0.02 MPa (VM2) to 3.07 ±0.45 MPa (CES). The qualitative assessment of margin edge roughness revealed visible differences among the tested materials, with mean roughness measurements ranging from 60 ±16 μm (CES) to 190 ±15 μm (EMP). The material factor had a significant effect on the mean flexural strength (Pmaterials tested in this study exhibited

  10. Evaluation of internal adaptation of dental adhesive restorations using micro-CT

    Directory of Open Access Journals (Sweden)

    Oh-Hyun Kwon

    2012-02-01

    Full Text Available Objectives The internal adaptation of composite restorations with or without resin modified glass ionomer cement (RMGIC was analyzed non-destructively using Microcomputed tomography (micro-CT. Materials and Methods Thirty intact human teeth were used. The specimens were divided into 3 groups. In the control group, the cavities were etched with 10% phosphoric acid for 15 sec. Composite resin was filled into the cavity without adhesive. In group 1, light cured glass ionomer cement (GIC, Fuji II LC, GC was applied as a base. The cavities were then etched, bonded, light cured and filled with composites. In group 2, the cavities were then etched, bonded, light cured and filled with composites without base application. They were immersed in a 25% silver nitrate solution. Micro-CT was performed before and after mechanical loading. One-way ANOVA with Duncan analysis was used to compare the internal adaptation between the groups before or after loading. A paired t-test was used to compare internal adaptation before and after mechanical loading. All statistical inferences were made within the 95% confidence interval. Results The silver nitrate solution successfully penetrated into the dentinal tubules from the pulp spaces, and infiltrated into the gap between restoration and pulpal floor. Group 2 showed a lower adaptation than the control group and group 1 (p < 0.05. There was no significant difference between the control group and group 1. For all groups, there was a significant difference between before and after mechanical loading (p < 0.05. Conclusions The internal adaptation before and after loading was better when composites were bonded to tooth using adhesive than composites based with RMGIC.

  11. Three-Point Bending Tests of Zirconia Core/Veneer Ceramics for Dental Restorations

    Directory of Open Access Journals (Sweden)

    Massimo Marrelli

    2013-01-01

    Full Text Available Introduction. The mechanical strength and the surface hardness of commercially available yttrium-doped zirconia were investigated. Furthermore, a comparative study of eight different ceramic veneers, to be used for the production of two-layered all-ceramic restorative systems, was carried out. Materials and Methods. Four types of zirconia specimens were analyzed, according to a standard ISO procedure (ISO 6872. Besides, two-layered zirconia-veneer specimens were prepared for three-point bending tests. Results. A strong effect of the surface roughness on the mechanical strength of zirconia specimens was observed. Finally, a comparative study of eight commercially available veneering ceramics shows different modes of failure between the selected veneers. Conclusion. The results indicate that close attention should be paid to the preparation of zirconia-based crowns and bridges by CAD/CAM process, because surface roughness has an important effect on the mechanical strength of the material. Finally, the results of the mechanical tests on two-layered specimens represent an important support to the choice of the veneering ceramic.

  12. An in vitro atomic force microscopic study of commercially available dental luting materials.

    Science.gov (United States)

    Djordje, Antonijevic; Denis, Brajkovic; Nenadovic, Milos; Petar, Milovanovic; Marija, Djuric; Zlatko, Rakocevic

    2013-09-01

    The aim of this in vitro study was to compare the surface roughness parameters of four different types of dental luting agents used for cementation of implant restorations. Five specimens (8 mm high and 1 mm thick) of each cement were made using metal ring steelless molds. Atomic Force Microscope was employed to analyze different surface texture parameters of the materials. Bearing ratio analysis was used to calculate the potential microgap size between the cement and implant material and to calculate the depth of the valleys on the cement surface, while power spectral density (PSD) measurements were performed to measure the percentage of the surface prone to bacterial adhesion. Glass ionomer cement showed significantly lower value of average surface roughness then the other groups of the materials (P cement experience the lowest percentage of the surface which promote bacterial colonization. Glas ionomer cements present the surface roughness parameters that are less favorable for bacterial adhesion than that of zinc phosphate, resin-modified glass ionomer and resin cements. Copyright © 2013 Wiley Periodicals, Inc.

  13. The immediate insertion, loading and provisional prosthetic restoration of dental implants.

    Science.gov (United States)

    Sârbu, I

    2008-01-01

    The immediate insertion and loading of dental implants although used in the past as an alternative method for the surgical phase of the dental implant treatment is today becoming more and more popular due to its immediate and spectacular results. With information on bone density and a careful patient selection, this method has increased chances of success. Its main advantage is the high degree of patient comfort with a great aesthetic effect. This article presents the theoretical and practical technique used on two clinical cases of dental implantation and their outcome.

  14. Effect of fluoride varnishes on color stability of esthetic restorative materials.

    Science.gov (United States)

    Autio-Gold, Jaana T; Barrett, Allyson A

    2004-01-01

    (deltaE*=1.19 and deltaL*=-1.03), indicating the effect of the color change was due to absorption. After fluoride varnish applications, Duraphat varnish produced significant changes in all tested materials and shades, resulting in color changes with deltaE greater than (>) 1 but less than (dental literature as clinically acceptable. Fluoride varnishes can be used without adversely affecting the color of restorative materials.

  15. Determination of dose rate from natural radionuclide in porcelain dental materials

    International Nuclear Information System (INIS)

    Nouri, A.D.; El-Zourgany, A.; Elmashat, Alia; El-Masri, Karima

    2010-01-01

    There are three main aims that make this study particularly important and interesting to radiometric studies. Firstly, it will provides information on the concentration composition of natural and the associated man-made radioactivity of imported dental porcelain materials to be used by most dental laboratories in Great Jamahiriya. Since these materials do not pass radiation inspection tests before their entry or use and there is a large variety of supply source of these dental materials to be used for all dental works on Libyan patients, anomalies can be identified easily. Secondly, the analysis of selective elemental abundance (U, Th, and K ) and dose rate calculations may be used to calculate effective dose rates to dental laboratory technicians and also to the patient who will be using these specific materials. This research project will provide the first results of such measurements and the corresponding average annual effective dose rates equivalent to the patients using these materials and also to the dental technician and doctors work in the various dental laboratories that make use of these materials in their daily work. A total number of 30 dental powder samples were collected from a number of dental laboratories around Tripoli area will be analyzed. In this research project, the results from this preliminary survey regarding Th, U and K elemental concentrations in a wide variety of dental materials by means of high-resolution X-ray spectrometry will be presented. Further results from these investigations concerning activity concentrations and the associated dose rates, effective dose and the committed dose due to the use of these materials are going to be calculated and compared with other published data elsewhere and recommendation of their use will be derived accordingly. (author)

  16. Comparison of Micro-Leakage around Temporary Restorative Materials Placed in Complex Endodontic Access Cavities: An In-Vitro Study

    International Nuclear Information System (INIS)

    Adnan, S.; Khan, F. R.

    2016-01-01

    Objective: To compare mean micro-leakage around 3 types of temporary restorative materials in-vitro, when placed adjacent to permanent restorations (amalgam) in complex endodontic access cavities. Study Design: Randomized controlled trial. Place and Duration of Study: Dental Clinics, Dental Laboratory and Research Laboratory at The Aga Khan University Hospital, Karachi, from January to Jun 2014. Methodology: After random allocation of 60 teeth into 3 experimental groups, each group had conventional class II cavities prepared and amalgam placed. After 14 days, endodontic access cavities were made in these teeth, followed byplacement of Cavit, IRM and CLIP (depth of 4 mm each). After thermo-cycling and immersion in 0.5 percentage methylene blue dye, the teeth were sectioned mesio-distally and observed under stereoscopic microscope (magnification * 4) along 2 interfaces 'a' and 'b' (tooth-temporary restoration and temporary restoration-primary restoration), respectively. Depth of dye penetration was measured in millimeters. Results: IRM was leakiest at interface 'a', cavit had highest dye penetration at interface 'b', while CLIP exhibited least micro-leakage at 'a' and 'b'. The mean dye penetration for Cavit was 0.80 ± 0.23 mm at 'a', and 2.24 ± 0.48 mm at 'b'. For IRM, it was 1.82 ± 0.09 mm at 'a', and 0.44 ± 0.13 mm at 'b'. For CLIP, the mean dye penetration was 0.43 ± 0.05 mm at 'a', and 0.32 ± 0.12 mm at 'b'. The difference in dye penetration observed between the 3 groups at both interfaces was statistically significant. Conclusion: In a complex access cavity made adjacent to a pre-existing amalgam restoration, CLIP exhibits the least micro-leakage, followed by IRM and Cavit. (author)

  17. Surface texture measurement for dental wear applications

    Science.gov (United States)

    Austin, R. S.; Mullen, F.; Bartlett, D. W.

    2015-06-01

    The application of surface topography measurement and characterization within dental materials science is highly active and rapidly developing, in line with many modern industries. Surface measurement and structuring is used extensively within oral and dental science to optimize the optical, tribological and biological performance of natural and biomimetic dental materials. Although there has historically been little standardization in the use and reporting of surface metrology instrumentation and software, the dental industry is beginning to adopt modern areal measurement and characterization techniques, especially as the dental industry is increasingly adopting digital impressioning techniques in order to leverage CAD/CAM technologies for the design and construction of dental restorations. As dental treatment becomes increasingly digitized and reliant on advanced technologies such as dental implants, wider adoption of standardized surface topography and characterization techniques will become evermore essential. The dental research community welcomes the advances that are being made in surface topography measurement science towards realizing this ultimate goal.

  18. [Effect of removable partial dentures restoration on oral health-related quality of life of patients with shortened dental arch].

    Science.gov (United States)

    Fu, Zhen-nan; Lin, Xue-feng

    2013-11-01

    To assess the effect of removable partial dentures (PRD) restoration on oral health-related quality of life (OHRQOL) of subjects with shortened dental arches (SDA) using the Chinese version of the Oral Health Impact Profile (OHIP-14). Consecutive patients with shortened dental arches were recruited from the Department of Prosthodontics, Foshan Chancheng Hospital of Stomatology. The Chinese version of OHIP-14 was administered to each subject before treatment and after treatment. The subjective outcomes of removable partial dentures therapy on SDA were collected and the pre- and post-treatment scores of the Chinese version of OHIP-14 were compared. After treatment, significant decrease in patients' total score of OHRQOL [before: 9 (6, 12) ; after: 4 (2.25, 6)] was detected, as well as physical pain subscale, physical disability subscale and handicap subscale; and the score of OHRQOL in function limitation subscale increased [before: 0(0,0); after: 2(1, 2)]. The main impacts of shortened dental arch with intact anterior region affecting patients' OHRQOL are physical disability.From a quality-of-life perspective, patients with SDA can perceive benefits from RPD.

  19. In vitro shear bond strength of cementing agents to fixed prosthodontic restorative materials.

    Science.gov (United States)

    Piwowarczyk, Andree; Lauer, Hans-Christoph; Sorensen, John A

    2004-09-01

    Durable bonding to fixed prosthodontic restorations is desirable; however, little information is available on the strength of the bond between different cements and fixed prosthodontic restorative materials. This study determined the shear-bond strength of cementing agents to high-gold-content alloy castings and different dental ceramics: high-strength aluminum oxide (Procera AllCeram), leucite-reinforced (IPS Empress), and lithium disilicate glass-ceramic (IPS Empress 2). Prepolymerized resin composite cylinders (5.5 mm internal diameter, n=20) were bonded to the pretreated surfaces of prosthodontic materials. High-gold-content alloy and high-strength aluminum oxide surfaces were airborne-particle-abraded, and pressable ceramics were hydrofluoric acid-etched and silanized prior to cementing. The cementing agents tested were a zinc-phosphate cement (Fleck's zinc cement), glass ionomer cements (Fuji I, Ketac-Cem), resin-modified glass ionomer cements (Fuji Plus, Fuji Cem, RelyX Luting), resin cements (RelyX ARC, Panavia F, Variolink II, Compolute), and a self-adhesive universal resin cement (RelyX Unicem). Half the specimens (n=10) were tested after 30 minutes; the other half (n=10) were stored in distilled water at 37 degrees C for 14 days and then thermal cycled 1000 times between 5 degrees C and 55 degrees C prior to testing. Shear-bond strength tests were performed using a universal testing machine at a constant crosshead speed of 0.5 mm/min. Statistical analysis was performed by multifactorial analysis of variance taking interactions between effects into account. For multiple paired comparisons, the Tukey method was used (alpha=.05). In a 3-way ANOVA model, the main factors substrate, cement, time, and all corresponding interactions were statistically significant (all P <.0001). In subsequent separate 1-way or 2-way ANOVA models for each substrate type, significant differences between cement types and polymerizing modes were found (all P <.001). None of the

  20. Osteogenic differentiation of dental pulp stem cells under the influence of three different materials

    DEFF Research Database (Denmark)

    Ajlan, S. A.; Ashri, N. Y.; Aldahmash, Abdullah M.

    2015-01-01

    Background: Regeneration of periodontal tissues is a major goal of periodontal therapy. Dental pulp stem cells (DPSCs) show mesenchymal cell properties with the potential for dental tissue engineering. Enamel matrix derivative (EMD) and platelet-derived growth factor (PDGF) are examples of materi......Background: Regeneration of periodontal tissues is a major goal of periodontal therapy. Dental pulp stem cells (DPSCs) show mesenchymal cell properties with the potential for dental tissue engineering. Enamel matrix derivative (EMD) and platelet-derived growth factor (PDGF) are examples...

  1. Evaluation of enamel mineral loss around cavities prepared by the Er,Cr:YSGG laser and restored with different materials

    Science.gov (United States)

    Navarro, Ricardo Scarparo; Lago, Andréa. Dias Neves; Bonifácio, Clarissa Calil; Mendes, Fausto Medeiros; de Freitas, Patrícia Moreira; Baptista, Alessandra; Nunez, Silvia Cristina; Matos, Adriana Bona; Imparato, José Carlos P.

    2018-02-01

    The aim of this study was to evaluate the enamel demineralization around cavities prepared by Er,Cr:YSGG laser (2780 nm) and restored with different materials after an acid challenge. The human dental enamel samples were randomly divided in 12 groups (n=10): G1- high-speed drill (HD); G2- Er,Cr:YSGG laser L (3 W, 20 Hz, 53.05 J/cm2)(air 65% - water 55%); G3- L (4 W, 20 Hz, 70.74 J/cm2); G4- L (5 W, 20 Hz, 88.43 J/cm2). Each group was divided in subgroups: 1- glass ionomer cement (GIC), 2- resin modified GIC (RMGIC), 3- composite resin (C). Samples were submitted to an acid challenge (4.8 pH) for7 days. The calcium ion contend (ppm/mm2) from demineralizing solutions were analyzed by atomic emission spectrometry. ANOVA and LSD tests were performed (α=5%). The significant lower average values of calcium loss were observed on G2 + GIC, G2 + RMGIC, G1 + RMGIC (penamel demineralization. The findings of this in vitro study suggest that the Er,Cr:YSGG lased cavities restored with GIC or RMGIC or conventional drill cavities with RMGIC were effective on reducing the demineralization around restorations, showing an important potential in preventing secondary caries.

  2. Magnetic susceptibility and electrical conductivity of metallic dental materials and their impact on MR imaging artifacts

    Czech Academy of Sciences Publication Activity Database

    Starčuková, Jana; Starčuk jr., Zenon; Hubálková, H.; Linetskiy, I.

    2008-01-01

    Roč. 24, č. 6 (2008), s. 715-723 ISSN 0109-5641 R&D Projects: GA MZd NR8110 Institutional research plan: CEZ:AV0Z20650511 Keywords : metallic dental materials * dental alloys * amalgams * MR imaging * magnetic susceptibility * electric conductivity * image artifact Subject RIV: FF - HEENT, Dentistry Impact factor: 2.941, year: 2008

  3. Investigation on adhering properties of dental materials by means of radioactively labelled bacteria

    International Nuclear Information System (INIS)

    Pfister, W.; Kleinert, P.; Sandig, H.C.; Wutzler, P.; Ruschitschka, A.; Schaefer, U.

    1987-01-01

    Bacteria of the species Streptococcus mutans were radioactively labelled with 113 In-oxinate. Different dental materials were incubated with the labelled bacteria. Counts per minute of the dental materials could be determined as proportion of the quantity of adhering microorganisms. Silver-palladium-alloy had a lower adherence than silver-tin-alloy. Finest polished alloys had lower adhering properties than unpolished surfaces of materials. (author)

  4. A field-trial of two restorative materials used with atraumatic restorative treatment in rural Turkey: 24-month results

    Directory of Open Access Journals (Sweden)

    Ertugrul Ercan

    2009-08-01

    Full Text Available OBJECTIVE: The purpose of this study was to investigate the clinical performance of high-strength glass ionomer cement (HSGIC and resin-modified glass ionomer (RMGIC in single and multiple surface carious cavities in the field conditions. MATERIAL AND METHODS: A split-mouth design, including ninety-one fillings placed on contra lateral molar pairs of 37 children, was used in permanent dentition. As filling materials, a HSGIC (Ketac Molar/3M ESPE and a RMGIC (Vitremer/ 3M ESPE were used with the Atraumatic Restorative Treatment (ART. Baseline and 6, 12 and 24-month evaluations of the fillings were made with standard-ART and USPHS criteria by two examiners with kappa values of 0.92 and 0.87 for both criteria. RESULTS: According to the USPHS criteria, the retention rates of RMGIC and HSGIC restorations were 100% and 80.9% for single surface, and 100% and 41.2% for multiple surface restorations after 24 months, respectively. Irrespective of surface number, RMGIC was significantly superior to HSGIC (p= 0.004, according to both standard-ART and USPHS criteria. CONCLUSION: The results indicate that RMGIC may be an alternative restorative technique in comparison to high-strength GIC applications in ART-field-trials. However, further clinical and field trials are needed to support this conclusion.

  5. A finite element analysis of novel vented dental abutment geometries for cement-retained crown restorations.

    Science.gov (United States)

    Rodriguez, Lucas C; Saba, Juliana N; Meyer, Clark A; Chung, Kwok-Hung; Wadhwani, Chandur; Rodrigues, Danieli C

    2016-11-01

    Recent literature indicates that the long-term success of dental implants is, in part, attributed to how dental crowns are attached to their associated implants. The commonly utilized method for crown attachment - cementation, has been criticized because of recent links between residual cement and peri-implant disease. Residual cement extrusion from crown-abutment margins post-crown seating is a growing concern. This study aimed at (1) identifying key abutment features, which would improve dental cement flow characteristics, and (2) understanding how these features would impact the mechanical stability of the abutment under functional loads. Computational fluid dynamic modeling was used to evaluate cement flow in novel abutment geometries. These models were then evaluated using 3D-printed surrogate models. Finite element analysis also provided an understanding of how the mechanical stability of these abutments was altered after key features were incorporated into the geometry. The findings demonstrated that the key features involved in improved venting of the abutment during crown seating were (1) addition of vents, (2) diameter of the vents, (3) location of the vents, (4) addition of a plastic screw insert, and (5) thickness of the abutment wall. This study culminated in a novel design for a vented abutment consisting of 8 vents located radially around the abutment neck-margin plus a plastic insert to guide the cement during seating and provide retrievability to the abutment system.Venting of the dental abutment has been shown to decrease the risk of undetected residual dental cement post-cement-retained crown seating. This article will utilize a finite element analysis approach toward optimizing dental abutment designs for improved dental cement venting. Features investigated include (1) addition of vents, (2) diameter of vents, (3) location of vents, (4) addition of plastic screw insert, and (5) thickness of abutment wall.

  6. A finite element analysis of novel vented dental abutment geometries for cement‐retained crown restorations

    Science.gov (United States)

    Rodriguez, Lucas C.; Saba, Juliana N.; Meyer, Clark A.; Chung, Kwok‐Hung; Wadhwani, Chandur

    2016-01-01

    Abstract Recent literature indicates that the long‐term success of dental implants is, in part, attributed to how dental crowns are attached to their associated implants. The commonly utilized method for crown attachment – cementation, has been criticized because of recent links between residual cement and peri‐implant disease. Residual cement extrusion from crown‐abutment margins post‐crown seating is a growing concern. This study aimed at (1) identifying key abutment features, which would improve dental cement flow characteristics, and (2) understanding how these features would impact the mechanical stability of the abutment under functional loads. Computational fluid dynamic modeling was used to evaluate cement flow in novel abutment geometries. These models were then evaluated using 3D‐printed surrogate models. Finite element analysis also provided an understanding of how the mechanical stability of these abutments was altered after key features were incorporated into the geometry. The findings demonstrated that the key features involved in improved venting of the abutment during crown seating were (1) addition of vents, (2) diameter of the vents, (3) location of the vents, (4) addition of a plastic screw insert, and (5) thickness of the abutment wall. This study culminated in a novel design for a vented abutment consisting of 8 vents located radially around the abutment neck‐margin plus a plastic insert to guide the cement during seating and provide retrievability to the abutment system.Venting of the dental abutment has been shown to decrease the risk of undetected residual dental cement post‐cement‐retained crown seating. This article will utilize a finite element analysis approach toward optimizing dental abutment designs for improved dental cement venting. Features investigated include (1) addition of vents, (2) diameter of vents, (3) location of vents, (4) addition of plastic screw insert, and (5) thickness of abutment wall. PMID

  7. A comparison of fatigue resistance of three materials for cusp-replacing adhesive restorations.

    NARCIS (Netherlands)

    Kuijs, R.H.; Fennis, W.M.M.; Kreulen, C.M.; Roeters, F.J.M.; Verdonschot, N.J.J.; Creugers, N.H.J.

    2006-01-01

    OBJECTIVES: To investigate the fatigue resistance and failure behaviour of cusp-replacing restorations in premolars using different types of adhesive restorative materials. METHODS: A class 2 cavity was prepared and the buccal cusp was removed in an extracted sound human upper premolar. By using a

  8. Survival of extensively damaged endodontically treated incisors restored with different types of posts-and-core foundation restoration material.

    Science.gov (United States)

    Lazari, Priscilla Cardoso; de Carvalho, Marco Aurélio; Del Bel Cury, Altair A; Magne, Pascal

    2018-05-01

    analysis (log-rank post hoc test at α=.05 for pairwise comparisons). None of the tested specimen withstood all 140 000 cycles. All specimens without a ferrule were affected by an initial failure phenomenon (wide gap at the lingual margin between the core foundation restoration/crown assembly and the root). NfPfP, NfPt, and NfPtB had similar survival (29649 to 30987 mean cycles until initial failure). NfPfB outperformed NfPt and NfPtB. None of the post-and-core foundation restoration materials were able to match the performance of the ferrule group FPf (72667 cycles). In all groups, 100% of failures were catastrophic. The survival of extensively damaged endodontically treated incisors without a ferrule was slightly improved by the use of a fiber post with a bulk-fill composite resin core foundation restoration. However, none of the post-and-core techniques was able to compensate for the absence of a ferrule. The presence of the posts always adversely affected the failure mode. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  9. Bioinspired design of dental multilayers.

    Science.gov (United States)

    Huang, M; Wang, R; Thompson, V; Rekow, D; Soboyejo, W O

    2007-01-01

    This paper considers the use of bioinspired functionally graded structures in the design of dental multi-layers that are more resistant to sub-surface crack nucleation. Unlike existing dental crown restorations that give rise to high stress concentration, the functionally graded layers (between crown materials and the joins that attach them to dentin) are shown to promote significant reductions in stress and improvements in the critical crack size. Special inspiration is drawn from the low stress concentrations associated with the graded distributions in the dentin-enamel-junction (DEJ). The implications of such functionally graded structures are also discussed for the design of dental restorations.

  10. Profile of accidents with biological material at a dental school

    Directory of Open Access Journals (Sweden)

    Sandra Aragão de Almeida Sasamoto

    2014-09-01

    Full Text Available http://dx.doi.org/10.4025/actascihealthsci.v36i1.14976 Current research characterizes the epidemiological profile of accidents with biological material (BM that occurred in a government-run dental school and identifies the post-exposure behavior taken by the injured subjects. The cross-sectional retrospective study comprises professors, students and technical-administration personnel who worked in the laboratory from 2001 to 2008 (n = 566. An electronic questionnaire, prepared by software developed for this purpose, was sent to subjects between May and August 2008 for data collection. Ninety-one (34.2% out of 266 participants reported some type of exposure to BM. There was no difference between the occurrence of accidents according to the subjects’ category (p = 0.496 and sex (p = 0.261. Most of the subjects reported cutaneous exposure (76.9% comprising saliva (68.1% and blood (48.3%. The fingers were the body members most affected. Accidents occurred mostly during clinical (34.1% and surgical (30.8% procedures. Although the use of protection equipments was high (82.9%, only 26.4% of subjects reported the accident and only 28.6% sought immediate help. Most of the injured subjects failed to report the accidents and did not comply with the guidelines. Others trivialized basic behavior such as the interruption of the procedure to seek medical assistance.

  11. Biocompatibility of dental alloys

    Energy Technology Data Exchange (ETDEWEB)

    Braemer, W. [Heraeus Kulzer GmbH and Co. KG, Hanau (Germany)

    2001-10-01

    Modern dental alloys have been used for 50 years to produce prosthetic dental restorations. Generally, the crowns and frames of a prosthesis are prepared in dental alloys, and then veneered by feldspar ceramics or composites. In use, the alloys are exposed to the corrosive influence of saliva and bacteria. Metallic dental materials can be classified as precious and non-precious alloys. Precious alloys consist of gold, platinum, and small amounts of non-precious components such as copper, tin, or zinc. The non-precious alloys are based on either nickel or cobalt, alloyed with chrome, molybdenum, manganese, etc. Titanium is used as Grade 2 quality for dental purposes. As well as the dental casting alloys, high purity electroplated gold (99.8 wt.-%) is used in dental technology. This review discusses the corrosion behavior of metallic dental materials with saliva in ''in vitro'' tests and the influence of alloy components on bacteria (Lactobacillus casei and Streptococcus mutans). The test results show that alloys with high gold content, cobalt-based alloys, titanium, and electroplated gold are suitable for use as dental materials. (orig.)

  12. The challenge for innovation in direct restorative materials

    DEFF Research Database (Denmark)

    Bayne, S; Petersen, P E; Piper, D

    2013-01-01

    During the past 50 years, a series of key UN conferences have established a framework to minimize human health risks from environmental exposures to key chemicals. In January 2013, more than 140 countries agreed to the text of new treaty to minimize Hg effects on the environment (the Minamata....... Safety is freedom from unacceptable risks. Risk is a combination of probability of exposure and severity of harm. Best management practices are crucial to manage dental amalgam, but these impose additional that are disproportionately more for developing countries. The Minamata Convention seeks a phase...

  13. Fracture Resistance of Endodontically Treated Teeth Restored with Biodentine, Resin Modified GIC and Hybrid Composite Resin as a Core Material.

    Science.gov (United States)

    Subash, Dayalan; Shoba, Krishnamma; Aman, Shibu; Bharkavi, Srinivasan Kumar Indu; Nimmi, Vijayan; Abhilash, Radhakrishnan

    2017-09-01

    The restoration of a severely damaged tooth usually needs a post and core as a part of treatment procedure to provide a corono - radicular stabilization. Biodentine is a class of dental material which possess high mechanical properties with excellent biocompatibility and bioactive behaviour. The sealing ability coupled with optimum physical properties could make Biodentine an excellent option as a core material. The aim of the study was to determine the fracture resistance of Biodentine as a core material in comparison with resin modified glass ionomer and composite resin. Freshly extracted 30 human permanent maxillary central incisors were selected. After endodontic treatment followed by post space preparation and luting of Glass fibre post (Reforpost, Angelus), the samples were divided in to three groups based on the type of core material. The core build-up used in Group I was Biodentine (Septodont, France), Group II was Resin-Modified Glass Ionomer Cement (GC, Japan) and Group III was Hybrid Composite Resin (TeEconom plus, Ivoclar vivadent). The specimens were subjected to fracture toughness using Universal testing machine (1474, Zwick/Roell, Germany) and results were compared using One-way analysis of variance with Tukey's Post hoc test. The results showed that there was significant difference between groups in terms of fracture load. Also, composite resin exhibited highest mean fracture load (1039.9 N), whereas teeth restored with Biodentine demonstrated the lowest mean fracture load (176.66 N). Resin modified glass ionomer exhibited intermediate fracture load (612.07 N). The primary mode of failure in Group I and Group II was favourable (100%) while unfavourable fracture was seen in Group III (30%). Biodentine, does not satisfy the requirements to be used as an ideal core material. The uses of RMGIC's as a core build-up material should be limited to non-stress bearing areas. Composite resin is still the best core build-up material owing to its high fracture

  14. EFFECTS OF POLISHING TIME AND THERMALCYCLINGON THE MICROLEAKAGE OF FOUR TOOTH –COLOURED DIRECT RESTORATIVE MATERIALS

    Directory of Open Access Journals (Sweden)

    V MORTAZAVI

    2002-09-01

    Full Text Available Introdaction. Microleakage has been recognized as a major clinical problem with direct filled dental restorations.The purpose of this study was to investigate and to compare the microleakage of four direct filled tooth-coloured materials, evaluation the effects of polishing time and thermocycling on the microleakage of these materials. Methods. Wedge-shaped class V cavities were prepared on buccal and lingual surfaces of 96 intact extracted human molar teeth. The teeth were randomly divided into three treatment groups and four subgroups. The cavities of each subgroup were filled using one of these materials: a conventional glass ionomer; a resin modified glass ionomer; a composite resin and a compomer. Polishing in the teeth of group 1 was done immediately after placement of restorations and in group 2 one week later. In group 3 delayed polishing and thermocycling (X100 was done. All of the teeth were stored in distilled water for one week and then stained with dye, sectioned, and scored for microleakage on occlusal and cervical edges. Results were statistically analyzed by Kruskal wallis and Mann whitney tests. Results. There was a statistically difference between the microleakage scores of four materials (P < 0.001. Immediately polished glass ionomer and compomer groups have significantly more microleakage than delayed polished groups (P < 0.001. Thermocycting could infulence the microleakage of composite on cervical edges (P < 0.05. Discussion. The precense of differences between the nature of materials and also the surface treatment such as primer or etchant application could influence the microleakage. The prescence of differences in reaction rate between the materials and the time that they reach to their adequate mechanical strength and adhesive bond strength lead to presence of differences between the effect of polishing time on the microleakage scores of materials.

  15. Guidelines for Preservation, Conservation, and Restoration of Local History and Local Genealogical Materials.

    Science.gov (United States)

    RQ, 1993

    1993-01-01

    Presents guidelines adopted by the American Library Association (ALA) relating to the preservation, conservation, and restoration of local history and local genealogical materials. Topics addressed include assessing preservation needs; developing a plan; choosing appropriate techniques, including microduplication, photoduplication, electronic…

  16. Concentration Levels of Particulate Matter of Common Dental Lab Materials in a Military Dental Lab

    Science.gov (United States)

    2016-05-01

    technician.” British Dental Journal 1999, 186:380-381 22 Suvarna SR. “Allergy to methyl methacrylate: a review.” Clinical Dentistry Vol 6, Issue 9...Health Organization , Geneva, Web, 1998. 24 Marquardt W, Seiss M, Hickel R, Reichl FX. “Volatile methacrylates in dental practices” Journal of... International Journal for Quality Research 5 th IQC, May 20 2011:595-602 35 Cimrin A, Nuray K, Canan K, Tertemiz KC. “Pneumoconiosis

  17. Influence of citric acid on the surface texture of glass ionomer restorative materials.

    Science.gov (United States)

    Reddy, Dappili Swami Ranga; Kumar, Ramachandran Anil; Venkatesan, Sokkalingam Mothilal; Narayan, Gopal Shankar; Duraivel, Dasarathan; Indra, Rajamani

    2014-09-01

    This study determined the effectiveness of G-coat plus surface protective agent over petroleum jelly on the surface texture of conventional Glass ionomer restorative materials. Three chemically cured conventional glass ionomer restorative materials type II, type IX and ketac molar were evaluated in this study. Sixty specimens were made for each restorative material. They were divided into two groups of thirty specimens each. Of the sixty specimens, thirty were coated with G-coat plus (a nano-filler coating) and the rest with petroleum jelly. Thirty samples of both protective coating agents were randomly divided into six groups of five specimens and conditioned in citric acid solutions of differing pH (pH 2, 3, 4, 5, 6 & 7). Each specimen was kept in citric acid for three hours a day, and the rest of time stored in salivary substitute. This procedure was repeated for 8 days. After conditioning, the surface roughness (Ra, μm) of each specimen was measured using a surface profilometer (Taylor & Habson, UK). Data was analyzed using one-way analysis of variance (ANOVA) and Tukey's HSD test at a significance level of 0.05. The surface textures of all the tested glass ionomer restorative materials protected with G-coat plus were not significantly affected by acids at low pH. The surface textures of all the tested glass ionomer restorative materials protected with petroleum jelly coating were significantly affected by acids at low pH. The effects of pH on the surface texture of glass ionomer restoratives are material dependent. Among all the materials tested the surface texture of Type II GIC (Group I) revealed marked deterioration when conditioned in solutions of low pH and was statistically significant. Hence, a protective coating either with G-coat plus or with light polymerized low viscosity unfilled resin adhesives is mandatory for all the glass ionomer restorations to increase the wear resistance of the restorative materials.

  18. Strength, toughness and aging stability of highly-translucent Y-TZP ceramics for dental restorations.

    Science.gov (United States)

    Zhang, Fei; Inokoshi, Masanao; Batuk, Maria; Hadermann, Joke; Naert, Ignace; Van Meerbeek, Bart; Vleugels, Jef

    2016-12-01

    © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  19. Beyond food: The multiple pathways for inclusion of materials into ancient dental calculus.

    Science.gov (United States)

    Radini, Anita; Nikita, Efthymia; Buckley, Stephen; Copeland, Les; Hardy, Karen

    2017-01-01

    Dental calculus (mineralized dental plaque) was first recognised as a potentially useful archaeological deposit in the 1970s, though interest in human dental calculus as a resource material has increased sharply in the past few years. The majority of recent research has focused on the retrieval of plant microfossils embedded in its matrix and interpretation of these finds as largely the result of deliberate consumption of plant-derived food. However, while most of the material described in published works does represent food, dental calculus is in fact a "depositional environment" as material can enter the mouth from a range of sources. In this respect, it therefore represents an archaeological deposit that can also contain extensive non-dietary debris. This can comprise a wide variety of cultural and environmental material which reaches the mouth and can become embedded in dental calculus through alternative pathways. Here, we explore the human behaviors and activities besides eating that can generate a flux of particles into the human mouth, the broad range of additional cultural and environmental information that can be obtained through the analysis and contextualisation of this material, and the implications of the additional pathways by which material can become embedded in dental calculus. © 2017 American Association of Physical Anthropologists.

  20. Cell death effects of resin-based dental material compounds and mercurials in human gingival fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Reichl, Franz-Xaver [Walther-Straub-Institute of Pharmacology and Toxicology, Munich (Germany); Ludwig-Maximilians-University, Department of Operative Dentistry and Periodontology, Munich (Germany); Esters, Magali; Simon, Sabine; Seiss, Mario [Walther-Straub-Institute of Pharmacology and Toxicology, Munich (Germany); Kehe, Kai [Bundeswehr Institute of Pharmacology and Toxicology, Munich (Germany); Kleinsasser, Norbert [University of Regensburg, Head and Neck Surgery, Department of Otolaryngology, Regensburg (Germany); Folwaczny, Matthias; Glas, Juergen; Hickel, Reinhard [Ludwig-Maximilians-University, Department of Operative Dentistry and Periodontology, Munich (Germany)

    2006-06-15

    In order to test the hypothesis that released dental restorative materials can reach toxic levels in human oral tissues, the cytotoxicities of the resin-based dental (co)monomers hydroxyethylmethacrylate (HEMA), triethyleneglycoldimethacrylate (TEGDMA), urethanedimethacrylate (UDMA), and bisglycidylmethacrylate (BisGMA) compared with methyl mercury chloride (MeHgCl) and the amalgam component mercuric chloride (HgCl{sub 2}) were investigated on human gingival fibroblasts (HGF) using two different test systems: (1) the modified XTT-test and (2) the modified H 33342 staining assay. The HGF were exposed to various concentrations of the test-substances in all test systems for 24 h. All tested (co)monomers and mercury compounds significantly (P<0.05) decreased the formazan formation in the XTT-test. EC{sub 50} values in the XTT assay were obtained as half-maximum-effect concentrations from fitted curves. Following EC{sub 50} values were found (mean [mmol/l]; s.e.m. in parentheses; n=12; * significantly different to HEMA): HEMA 11.530 (0.600); TEGDMA* 3.460 (0.200); UDMA* 0.106 (0.005); BisGMA* 0.087 (0.001); HgCl{sub 2}* 0.013 (0.001); MeHgCl* 0.005 (0.001). Following relative toxicities were found: HEMA 1; TEGDMA 3; UDMA 109; BisGMA 133; HgCl{sub 2} 887; MeHgCl 2306. A significant (P<0.05) increase of the toxicity of (co)monomers and mercurials was found in the XTT-test in the following order: HEMA < TEGDMA < UDMA < BisGMA < HgCl{sub 2} < MeHgCl. TEGDMA and MeHgCl induced mainly apoptotic cell death. HEMA, UDMA, BisGMA, and HgCl{sub 2} induced mainly necrotic cell death. The results of this study indicate that resin composite components have a lower toxicity than mercury from amalgam in HGF. HEMA, BisGMA, UDMA, and HgCl{sub 2} induced mainly necrosis, but it is rather unlikely that eluted substances (solely) can reach concentrations, which might induce necrotic cell death in the human physiological situation, indicating that other (additional) factors may be involved in

  1. Risk profile and quality of dental restorations: a cross-sectional study.

    Science.gov (United States)

    Sonbul, Helal; Birkhed, Dowen

    2010-03-01

    The aims of the present study were (1) to evaluate the percentage of recurrent caries with respect to the estimated caries risk profile obtained with a Cariogram, (2) to evaluate the quality of restorations in a Saudi population with several restorations and (3) to determine the additional value of bite-wing radiographs as an aid to quality evaluation. A total of 803 restorations were examined in 100 adults according to the United States Public Health Service/Ryge criteria. Salivary and microbiological factors, dietary habits and plaque index were investigated. The Cariogram was used to evaluate the risk profiles. Class II bite-wing radiographs (n = 281) were taken to examine the marginal integrity and the anatomic form proximally. The patients were categorized according to 'the chance of avoiding caries' into three risk groups: 0%-20% (n = 38), 21%-40% (n = 28) and 41%-100% (n = 34). ANOVA revealed statistically significant differences between the risk groups with respect to the recurrent caries (P percentage of the total restorations (56%) were diagnosed with recurrent caries. The quality of anatomic form and surface texture was unacceptable in the majority of cases. After adding the evaluations of class II bite-wings, the percentage of unacceptable restorations increased by 28% and 17% with regard to marginal integrity and anatomic form, respectively (P percentage 'chance of avoiding caries' as estimated by the Cariogram. The importance of bite-wings was emphasized as an aid to quality evaluation.

  2. Knowledge and Awareness among Parents and General Dental Practitioners regarding Rehabilitation with Full Coverage Restoration in Children: A Multi-centric Trial.

    Science.gov (United States)

    Moda, Aman; Saroj, Gyanendra; Sharma, Swati; Gupta, Basant

    2016-01-01

    The aim of this study was to evaluate the knowledge and awareness among parents and general dental practitioners regarding rehabilitation with full coverage restoration in children following pulp therapy. A multiple choice questionnaire was given to 1,000 parents and 400 general practitioners in this multicentric trial. The questionnaire assessed their beliefs, knowledge regarding care of primary teeth, assessment of treating children, and knowledge regarding importance of primary teeth. All the questionnaires were then compiled and statistically analyzed using Statistical Package for Social Sciences (SPSS) software. 53% parents did not know the importance of primary teeth and 73% parents also thought that no treatment is possible for pulpally involved primary teeth. 20% parents believed that root canal treatment can be possible for children and only 10% knew about full coverage restorations. 40% of the general dentists felt that the best treatment in the case of primary necrotic teeth is extraction and only 13% knew about stainless steel crowns. 62% of general dental practitioners pointed out patients' noninterest in providing crowns whereas 68% parents reported non-information by dentists. Both parents and general dental practitioners have incomplete and inadequate knowledge regarding full coverage restorations, and we need to improve the knowledge and dental awareness of the parents and the general dental practitioners. How to cite this article: Moda A, Saroj G, Sharma S, Gupta B. Knowledge and Awareness among Parents and General Dental Practitioners regarding Rehabilitation with Full Coverage Restoration in Children: A Multi-centric Trial. Int J Clin Pediatr Dent 2016;9(2):177-180.

  3. Recent advances in dental optics - Part I: 3D intraoral scanners for restorative dentistry

    Science.gov (United States)

    Logozzo, Silvia; Zanetti, Elisabetta M.; Franceschini, Giordano; Kilpelä, Ari; Mäkynen, Anssi

    2014-03-01

    Intra-oral scanning technology is a very fast-growing field in dentistry since it responds to the need of an accurate three-dimensional mapping of the mouth, as required in a large number of procedures such as restorative dentistry and orthodontics. Nowadays, more than 10 intra-oral scanning devices for restorative dentistry have been developed all over the world even if only some of those devices are currently available on the market. All the existing intraoral scanners try to face with problems and disadvantages of traditional impression fabrication process and are based on different non-contact optical technologies and principles. The aim of this publication is to provide an extensive review of existing intraoral scanners for restorative dentistry evaluating their working principles, features and performances.

  4. 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.

  5. NEW TECHNOLOGIES FOR RESTORATION AND PROTECTION OF POWER EQUIPMENT WITH THE AID OF COMPOSITE MATERIALS

    Directory of Open Access Journals (Sweden)

    A. O. Ischenko

    2017-01-01

    Full Text Available The analysis of possible variants of reconstruction of the power equipment is fulfilled and the conclusion concerning the prospects of such work with the use of composite materials is reached. The data on the technical characteristics of composite repair materials for various purposes are presented, the results of repairs of power equipment, in particular the technology for the recovery of the boarding surfaces of the diffuser rings and protection of the pumps D1250 casings are provided. The technology of the recovery pneumatic cylinder, hydraulic cylinder rod, as well as the unique technology of restoration of working surfaces of the impeller vanes of transfer pump, that had been destroyed by corrosion in conjunction with the cavitation processes and were considered as not restorable is described. The restored impeller was in operation during a year and only thereafter it was removed for restoration. Another composite material discussed in the article – diagum – makes it possible to perform a series of repairs associated with restoration of the rubber-covered surfaces of pump casings as well as with restoration of various surfaces of the conveyor belts. Taking the excellent adhesive properties of this composite into account, restoration of worn stainless steel sieve screens to remove abrasive material was fulfilled with the aid of it. The restoration was accomplished via the use of the conveyor belt which application time had expired, that was glued to a metal sieve with diagum. The use of the composites is economically justified, because the application of them in repairs reduces, firstly, terms of restoration work and, secondly, the price of repairs. Third, equipment that was damaged beyond repair is being commissioned by the use of the mentioned composites. 

  6. Determination of unreacted monomers in restorative dental resins based on dimethacrylate by NMR hydrogen

    International Nuclear Information System (INIS)

    Correa, Ivo Carlos; Miranda Junior, Walter G.; Tavares, Maria Ines B.

    2001-01-01

    The presence of unreacted monomers after photo-activation of dental composites causes mechanical and biological properties to decrease and could be detected by NMR analysis. The aim of this study was to evaluate the percentage of leachable monomers of light-cured composites under the effect of variations of exposure time of photo activation by nuclear magnetic resonance of hydrogen in solution (NMR 1 H). The composite resins tested Z250 and Fill Magic obtained similar values of unreacted monomers (%) at photo curing time suggested by the manufacturer and values were also lower than Durafill and A110 concentrations. From the NMR results, one day extractable time was efficient to quantify the amount of residual monomers in the dental composites tested, unless for Durafill composite. (author)

  7. [The effects of Ketac Molar Aplicap glass-ionomer material on growth of cariogenic bacteria contained in the dental plaque].

    Science.gov (United States)

    Płuciennik-Stronias, Małgorzata; Sakowska, Danuta; Paul-Stalmaszczyk, Małgorzata; Bołtacz-Rzepkowska, Elzbieta

    2012-01-01

    In the aging population, the prevalence of root caries has been observed, which is a characteristic feature of the elderly people. The most important element used in caries prevention is fluoride, which is derived from the air, diet or fluoride-containing preparations and materials, e.g. glass-ionomer restorations. The aim of the study was to evaluate the effect of Ketac Molar Aplicap glass-ionomer on the growth of Lactobacillus sp. bacteria, one of the species most frequently found in the carietic focus of the tooth root. The study was carried out in 15 patients with good oral hygiene, in whom 35 fillings from Ketac Molar Aplicap conventional glass-ionomer material were performed. After 6 months, three-day dental plaque from these fillings and from the tooth enamel of the control group was examined. No statistically significant differences (p = 0.554) in the amounts of Lactobacillus sp. between the study and control group were revealed. Lack of inhibiting effect of glass-ionomer material on the growth of the dental plaque with Lactobacillus sp. after the time of observation is implied.

  8. Teeth and bones: applications of surface science to dental materials and related biomaterials

    Science.gov (United States)

    Jones, F. H.

    2001-05-01

    Recent years have seen a considerable upsurge in publications concerning the surface structure and chemistry of materials with biological or biomedical applications. Within the body, gas-solid interactions become relatively less significant and solid-liquid or solid-solid interfaces dominate, providing new challenges for the surface scientist. The current paper aims to provide a timely review of the use of surface analysis and modification techniques within the biomaterials field. A broad overview of applications in a number of related areas is given with particular attention focusing on those materials commonly encountered in dentistry and oral or maxillofacial implantology. Several specific issues of current interest are discussed. The interaction between synthetic and natural solids, both in the oral environment and elsewhere in the body is important in terms of adhesion, related stresses and strains and ultimately the longevity of a dental restoration, biomedical implant, or indeed the surrounding tissue. Exposure to body fluids, of course, can also affect stability, leading to the degradation or corrosion of materials within the body. Whilst this could potentially be harmful, e.g., if cytotoxic elements are released, it may alternatively provide a route to the preferential release of beneficial substances. Furthermore, in some cases, the controlled disintegration of a biomaterial is desirable, allowing the removal of an implant, e.g., without the need for further surgery. The presence of cells in the immediate bioenvironment additionally complicates the situation. A considerable amount of current research activity is targeted at the development of coatings or surface treatments to encourage tissue growth. If this is to be achieved by stimulating enhanced cell productivity, determination of the relationship between cell function and surface composition is essential.

  9. [Individualized restorative designs and clinical evaluation for dental implants in the anterior esthetic zone with inappropriate conditions].

    Science.gov (United States)

    Dai, Wen-yong; Zhou, Guo-xing; Zhang, Xiao-zhen; Zhao, Yi; Wang, Jie; Yang, Yi; Zhu, Zhi-jun; Tang, Chun-bo

    2014-08-01

    To offer individualized restorative strategies for patients receiving dental implants in the anterior esthetic zone but with inappropriate available conditions and evaluate the clinical outcomes. Forty-six patients with 58 implants were recruited for the study in accordance with the criteria and received individualized implant prostheses in the anterior esthetic zone. The patients were followed up for 3-24 months, and the clinical outcomes were evaluated by pink and white esthetic scores (PES/WES). The patients were from 18 to 69 years old, and followed up for 12.6 months in average. According to the third month follow-up esthetic scores, for PES, 1.72% of the patients got low scores, 44.83% got medium scores and 53.45% got high scores; For WES, 0% got low scores, 20.69% got medium scores and 79.31% got high scores. No implant failure or peri-implantitis occurred. Individualized restorative designs for implants in the esthetic zone can effectively improve the appearance of the prostheses which originally have no appropriate available space. Close follow-up and monitoring of the peri-implant soft tissue and proper oral hygiene instructions are important to ensure the conditions of the prostheses.

  10. Physical properties and compatibility with dental stones of current alginate impression materials.

    Science.gov (United States)

    Murata, H; Kawamura, M; Hamada, T; Chimori, H; Nikawa, H

    2004-11-01

    This study examined physical properties and compatibility with dental stones of two types of alginate impression materials. Five powder-type alginate impression materials (Alginoplast EM, Aroma Fine, Algiace Z, Coe Alginate, Jeltrate Plus) and a paste-type alginate impression material (Tokuso AP-1) were used. The dynamic viscosity immediately after mixing was measured by means of a controlled-stress rheometer. The gelation times were determined according to Japanese Industrial Standards (JIS) T6505, and recovery from deformation, strain in compression and compressive strength were determined according to the International Organization for Standardization (ISO) specification 1563. Detail reproduction and surface roughness of type III dental stones (New Plastone, New Sunstone) and a type IV dental stone (Die Stone) were evaluated using a ruled test block as specified in the ISO specification 1563 and a profilometer, respectively. The alginate impression materials evaluated in this study were all in compliance with the ISO specification 1563 and JIS T6505. The alginate impression materials had similar mechanical properties after gelation, whilst a wide range of dynamic viscosity immediately after being mixed, gelation times and compatibility with dental stones were found among the materials. The paste-type material had a higher dynamic viscosity and a shorter gelation time than the powder-type materials. The best surface quality was obtained with the paste-type material/type III dental stone cast combinations. The materials should be selected in consideration of initial flow, setting characteristics and compatibility with dental stones. The results suggested that a paste-type material would better meet the requirements of an alginate impression material.

  11. Restoring proximal caries lesions conservatively with tunnel restorations.

    Science.gov (United States)

    Chu, Chun-Hung; Mei, May L; Cheung, Chloe; Nalliah, Romesh P

    2013-07-30

    The tunnel restoration has been suggested as a conservative alternative to the conventional box preparation for treating proximal caries. The main advantage of tunnel restoration over the conventional box or slot preparation includes being more conservative and increasing tooth integrity and strength by preserving the marginal ridge. However, tunnel restoration is technique-sensitive and can be particularly challenging for inexperienced restorative dentists. Recent advances in technology, such as the contemporary design of dental handpieces with advanced light-emitting diode (LED) and handheld comfort, offer operative dentists better vision, illumination, and maneuverability. The use of magnifying loupes also enhances the visibility of the preparation. The advent of digital radiographic imaging has improved dental imaging and reduced radiation. The new generation of restorative materials has improved mechanical properties. Tunnel restoration can be an option to restore proximal caries if the dentist performs proper case selection and pays attention to the details of the restorative procedures. This paper describes the clinical technique of tunnel restoration and reviews the studies of tunnel restorations.

  12. Modeling the Residual Stresses in Reactive Resins-Based Materials: a Case Study of Photo-Sensitive Composites for Dental Applications

    International Nuclear Information System (INIS)

    Grassia, Luigi; D'Amore, Alberto

    2010-01-01

    Residual stresses in reactive resins-based composites are associated to the net volumetric contraction (shrinkage) arising during the cross-linking reactions. Depending on the restoration geometry (the ratio of the free surface area to the volume of the cavity) the frozen-in stresses can be as high as the strength of the dental composites. This is the main reason why the effectiveness and then the durability of restorations with composites remains quite lower than those realized with metal alloys based materials. In this paper we first explore the possibility to circumvent the mathematical complexity arising from the determination of residual stresses in reactive systems three-dimensionally constrained. Then, the results of our modeling approach are applied to a series of commercially available composites showing that almost all samples develop residual stresses such that the restoration undergoes failure as soon as it is realized.

  13. Fracture resistance of endodontically treated teeth restored with a bulkfill flowable material and a resin composite.

    Science.gov (United States)

    Isufi, Almira; Plotino, Gianluca; Grande, Nicola Maria; Ioppolo, Pietro; Testarelli, Luca; Bedini, Rossella; Al-Sudani, Dina; Gambarini, Gianluca

    2016-01-01

    To determine and compare the fracture resistance of endodontically treated teeth restored with a bulk fill flowable material (SDR) and a traditional resin composite. Thirty maxillary and 30 mandibular first molars were selected based on similar dimensions. After cleaning, shaping and filling of the root canals and adhesive procedures, specimens were assigned to 3 subgroups for each tooth type (n=10): Group A: control group, including intact teeth; Group B: access cavities were restored with a traditional resin composite (EsthetX; Dentsply-Italy, Rome, Italy); Group C: access cavities were restored with a bulk fill flowable composite (SDR; Dentsply-Italy), except 1.5 mm layer of the occlusal surface that was restored with the same resin composite as Group B. The specimens were subjected to compressive force in a material static-testing machine until fracture occurred, the maximum fracture load of the specimens was measured (N) and the type of fracture was recorded as favorable or unfavorable. Data were statistically analyzed with one-way analysis of variance (ANOVA) and Bonferroni tests (Pcomposite and with a bulk fill flowable composite (SDR) was similar in both maxillary and mandibular molars and showed no significant decrease in fracture resistance compared to intact specimens. No significant difference was observed in the mechanical fracture resistance of endodontically treated molars restored with traditional resin composite restorations compared to bulk fill flowable composite restorations.

  14. Clinical Evaluation of Microhybrid Composite and Glass lonomer Restorative Material in Permanent Teeth.

    Science.gov (United States)

    Kharma, Khalil; Zogheib, Tatiana; Bhandi, Shilpa; Mehanna, Carina

    2018-02-01

    The aim of this study was to clinically compare glass ionomer cement (GIC) with microhybrid composite resin used in class I cavities on permanent teeth over a period of 9 months. A total of 40 teeth with class I cavities were divided into two groups (n = 20) and restored with GIC (EQUIA; GC) and microhybrid resin composite (Amelogen Plus; Ultradent). Restorations were evaluated at ×4.5 magnification using the United States Public Health Service (USPHS) criteria every 3 months. Statistical analysis was performed using the Fisher's exact test (a material handling, adaptation, and marginal staining. The results of this clinical study showed that GIC (EQUIA; GC) can be used for the restoration of permanent teeth and may be more appropriate for certain clinical situations than the resin composite material. EQUIA (GIC) is a viable alternative to resin composite in restoring class I cavities in permanent teeth.

  15. A review of the strength properties of dental ceramics.

    Science.gov (United States)

    Hondrum, S O

    1992-06-01

    New ceramic materials for restorative dentistry have been developed and introduced in recent years. This article reviews advantages and disadvantages of dental ceramics, concentrating on strength properties. Included are factors affecting the strength of dental ceramic materials and the most common mechanisms for increasing the strength of dental ceramics. The properties of presently available materials such as dispersion-strengthened ceramics, cast ceramics, and foil-reinforced materials are discussed. Current research efforts to improve the fracture resistance of ceramic restorative materials are reviewed. A description of methods to evaluate the strength of ceramics is included, as a caution concerning the interpretation of strength data reported in the literature.

  16. Immediate placement and restoration of dental implants in the esthetic region: clinical case series.

    Science.gov (United States)

    Khzam, Nabil; Mattheos, Nikos; Roberts, David; Bruce, William L; Ivanovski, Saso

    2014-01-01

    The objective of this study was to assess the hard and soft tissue changes following immediate placement and provisional restoration of single-tooth implants in the aesthetic zone. Thirteen patients with immediately placed and restored implants were included in this study. All participating patients underwent the same treatment strategy that involved removal of the failed tooth, flapless surgery, immediate implant placement, and connection of a screw-retained provisional restoration. Three months following implant placement, the temporary crowns were replaced by the definitive restorations. Implant survival rates, and hard and soft tissue changes were measured using periapical X-rays and photographs. The range of the observation period was between 12 and 37 months with a mean period of 23.2 ± 7.6 months. At the time of follow-up, all implants were present with no complications. Radiographic evaluation revealed a mean mesial bone gain of 1.20 ± 1.01 mm and a mean distal bone gain of 0.80 ± 1.14 mm, which reached statistical significance. The mean mid-buccal recession was 0.20 ± 0.78 mm, whereas the mesial and distal papillae height loss was 0.50 ± 1.26 mm and 0.30 ± 0.82 mm, respectively. The changes in the soft tissues did not reach statistical significance. Notwithstanding the limitation of a small sample size, this study shows that immediate implant placement and provisional restoration in the maxillary aesthetic zone can result in favorable treatment outcomes with regards to soft and hard tissues changes over a follow-up period of 23.2 ± 7.6 months. Most clinical trials investigating immediate implant placement and immediate restoration in the maxillary anterior zone have focused on implant survival and implant success, with particular emphasis on radiographically assessed hard tissues changes. However, this study assesses the soft tissue changes associated with this procedure, which is an important area of study

  17. Effect of dental materials on gluconeogenesis in rat kidney tubules

    NARCIS (Netherlands)

    Reichl, F.X.; Durner, J.; Mückter, H.; Elsenhans, B.; Forth, W.; Kunzelmann, K.H.; Hickel, R.; Spahl, W.; Hume, W.R.; Moes, G.W.

    1999-01-01

    The effect of dental composite components triethyleneglycoldimethacrylate (TEGDMA) and hydroxyethylmethacrylate (HEMA) as well as mercuric chloride (HgCl2) and methylmercury chloride (MeHgCl) on gluconeogenesis was investigated in isolated rat kidney tubules. From starved rats kidney tubules were

  18. Properties of New Glass Ionomer Restorative Materials Marketed for Stress Bearing Areas

    Science.gov (United States)

    2018-03-22

    REPORT TYPE 22/03/2018 Poster 4. TITLE AND SUBTITLE Prope1iies of New Glass-Ionomer Restorative Materials Marketed for Stress -Bearing Areas 6...Adobe Professional 7 .0 INTRODUCTION Equia Forte is a new GIC which is marketed for posterior stress bearing restorations due to its newer...research on this and other newer glass ionomer systems being indicated for use in class II posterior stress - bearing preparations. OBJECTIVE The

  19. Advances in Dental Materials through Nanotechnology: Facts, Perspectives and Toxicological Aspects.

    Science.gov (United States)

    Padovani, Gislaine C; Feitosa, Victor P; Sauro, Salvatore; Tay, Franklin R; Durán, Gabriela; Paula, Amauri J; Durán, Nelson

    2015-11-01

    Nanotechnology is currently driving the dental materials industry to substantial growth, thus reflecting on improvements in materials available for oral prevention and treatment. The present review discusses new developments in nanotechnology applied to dentistry, focusing on the use of nanomaterials for improving the quality of oral care, the perspectives of research in this arena, and discussions on safety concerns regarding the use of dental nanomaterials. Details are provided on the cutting-edge properties (morphological, antibacterial, mechanical, fluorescence, antitumoral, and remineralization and regeneration potential) of polymeric, metallic and inorganic nano-based materials, as well as their use as nanocluster fillers, in nanocomposites, mouthwashes, medicines, and biomimetic dental materials. Nanotoxicological aspects, clinical applications, and perspectives for these nanomaterials are also discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Evaluation of Candida Albicans Biofilm Formation on Various Dental ...

    African Journals Online (AJOL)

    2016-06-24

    Jun 24, 2016 ... This study compared the susceptibility of six dental restorative materials to Candida albicans adhesion. ... found for the composite and the compomer samples. ..... Candida colonization on acrylic resins and denture liners:.

  1. DESIGN AND TECHNOLOGICAL SOLUTIONS FOR THE RESTORATION OF SEWERS USING ELEMENTS OF RECYCLED POLYMER COMPOSITE MATERIALS

    Directory of Open Access Journals (Sweden)

    GONCHARENKO D. F.

    2017-01-01

    Full Text Available Problem statement. Currently sanitary drainage systems of large cities in Ukraine are significantly worn down with prolonged use and due to inefficient solutions for protection of the structures from aggressive effects of the environment, poor quality of materials and construction and installation works during building. Restoration of performance characteristics, reliability and durability of sewer tunnels is the costly and technically complex task, which is urgently needed to be fulfilled to prevent accidents including those with serious environmental impact. Modern work technique and the materials used for restoration allow us to solve these problems with different levels of efficiency, while reducing the cost of restoration due to use of recycled polymeric raw material, as well as to improvement of technological solutions is a currently important direction of research. Purpose of the article. To develop solutions for restoring serviceability, reliability and durability of sewer tunnels taking into account the accumulated experience in renovation of water disposal networks. Conclusion. Use of components made of recycled polymer composite materials during restoring sewer tunnels has significant economic and environmental effects and allows to undertake repair work in hard-to-reach areas.

  2. Use of a Novel ORMOCER as a Universal Direct Restorative Material.

    Science.gov (United States)

    Hakim, Foroud; Vallée, Jessie

    2018-01-01

    Composite resin is considered the material of choice for direct restoration of teeth when esthetic outcome is a high priority. While material science improvements have mitigated many of the traditional liabilities related to composite resin restorations, shrinkage and related shrinkage stress still play a role in outcomes, placement techniques, and overall success. This case report demonstrates two restorative scenarios using an ORMOCER® composite material. The first features a female patient who, upon completion of preliminary orthodontic treatment, determined in consultation with the orthodontist that her central incisors would present more idealistic display and esthetics if they were lengthened by approximately 1.5 mm. The lengthening of the incisors was to precede the phase II refinement with clear aligners, which would aim to extrude the remaining anterior teeth to develop incisal balance and symmetry. The second case is that of a woman who presented with a newly symptomatic upper right second bicuspid with an existing nearly decade old, large MODL composite resin restoration. This article demonstrates the universal nature of the novel direct restorative material used, making it well-suited for both anterior and posterior applications.

  3. Physical properties of a new sonically placed composite resin restorative material.

    Science.gov (United States)

    Ibarra, Emily T; Lien, Wen; Casey, Jeffery; Dixon, Sara A; Vandewalle, Kraig S

    2015-01-01

    A new nanohybrid composite activated by sonic energy has been recently introduced as a single-step, bulk-fill restorative material. The purpose of this study was to compare the physical properties of this new composite to various other composite restorative materials marketed for posterior or bulk-fill placement. The following physical properties were examined: depth of cure, volumetric shrinkage, flexural strength, flexural modulus, fracture toughness, and percent porosity. A mean and standard deviation were determined per group. One-way ANOVA and Tukey's post hoc tests were performed per property (α = 0.05). Percent porosity was evaluated with a Kruskal-Wallis/Mann-Whitney test (α = 0.005). Significant differences were found between groups (P composite restorative materials, the new nanohybrid composite showed low shrinkage and percent porosity, moderate fracture toughness and flexural modulus, and high flexural strength. However, it also demonstrated a relatively reduced depth of cure compared to the other composites.

  4. A comparison of microhardness of indirect composite restorative materials

    DEFF Research Database (Denmark)

    Miranda, Carolina Baptista; Pagani, Clóvis; Bottino, Marco Cícero

    2003-01-01

    The purpose of this study was to compare the microhardness of four indirect composite resins. Forty cylindrical samples were prepared according to the manufacturer’s recommendations using a Teflon mold. Ten specimens were produced from each tested material, constituting four groups (n=10) as foll...... esthetics and adequate mechanical properties may be considered as substitutes of natural teeth....

  5. Detection of Nanoparticles Released at Finishing of Dental Composite Materials.

    Czech Academy of Sciences Publication Activity Database

    Bradna, P.; Ondráčková, Lucie; Ždímal, Vladimír; Navrátil, Tomáš; Pelclová, D.

    2017-01-01

    Roč. 148, č. 3 (2017), s. 531-537 ISSN 0026-9247. [International Conference on Modern Electrochemical Methods /36./. Jetřichovice, 23.05.2016-27.05.2016] Institutional support: RVO:67985858 ; RVO:61388955 Keywords : dental composite * grinding * nanoparticles * aerosol * health risk Subject RIV: DN - Health Impact of the Environment Quality; CF - Physical ; Theoretical Chemistry (UFCH-W) OBOR OECD: Public and environmental health; Physical chemistry (UFCH-W) Impact factor: 1.282, year: 2016

  6. Color stability of sealed composite resin restorative materials after ultraviolet artificial aging and immersion in staining solutions.

    Science.gov (United States)

    Catelan, Anderson; Briso, André Luiz Fraga; Sundfeld, Renato Hermann; Goiato, Marcelo Coelho; dos Santos, Paulo Henrique

    2011-04-01

    The color alteration of resin-based materials is one of the most common reasons to replace esthetic dental restorations. This study assessed the influence of surface sealant (Biscover) on the color stability of nanofilled (Supreme XT) and microhybrid (Vit-l-escence and Opallis) composite resins after artificial aging. One hundred disc-shaped (6 × 1.5 mm) specimens were made for each composite resin. After 24 hours, all specimens were polished and sealant was applied to 50 specimens of each material. Baseline color was measured according to the CIE L*a*b* system using a reflection spectrophotometer. Ten specimens of each group were aged for 252 h in an ultraviolet (UV)-accelerated aging chamber or immersed for 4 weeks in cola soft drink, orange juice, red wine staining solutions or distilled water as control. Color difference (ΔE) after aging was calculated based on the color coordinates before (baseline) and after aging/staining treatment. Data were analyzed with 2-way ANOVA and Fisher's test (α=.05). The results showed significant changes in color after artificial aging in all the groups (Paging, and the cola soft drink. The lowest values of ΔE were found for specimens stored in distilled water. All composite resins showed some color alteration after the aging methods. The surface sealant did not alter the color stability of the tested materials. Copyright © 2011 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

  7. Effect of prophylactic polishing protocols on the surface roughness of esthetic restorative materials.

    Science.gov (United States)

    Neme, A L; Frazier, K B; Roeder, L B; Debner, T L

    2002-01-01

    Many polishing protocols have been evaluated in vitro for their effect on the surface roughness of restorative materials. These results have been useful in establishing protocols for in vivo application. However, limited research has focused on the subsequent care and maintenance of esthetic restorations following their placement. This investigation evaluated the effect of five polishing protocols that could be implemented at recall on the surface roughness of five direct esthetic restorative materials. Specimens (n=25) measuring 8 mm diameter x 3 mm thick were fabricated in an acrylic mold using five light-cured resin-based materials (hybrid composite, microfilled composite, packable composite, compomer and resin-modified glass ionomer). After photopolymerization, all specimens were polished with Sof-Lex Disks to produce an initial (baseline) surface finish. All specimens were then polished with one of five prophylactic protocols (Butler medium paste, Butler coarse paste, OneGloss, SuperBuff or OneGloss & SuperBuff). The average surface roughness of each treated specimen was determined from three measurements with a profilometer (Surface 1). Next, all specimens were brushed 60,000 times at 1.5 Hz using a brush-head force of 2 N on a Manly V-8 cross-brushing machine in a 50:50 (w/w) slurry of toothpaste and water. The surface roughness of each specimen was measured after brushing (Surface 2) followed by re-polishing with one of five protocols, then final surface roughness values were determined (Surface 3). The data were analyzed using repeated measures ANOVA. Significant differences (p=0.05) in surface roughness were observed among restorative materials and polishing protocols. The microfilled and hybrid resin composite yielded significantly rougher surfaces than the other three materials following tooth brushing. Prophylactic polishing protocols can be used to restore a smooth surface on resin-based esthetic restorative materials following simulated tooth

  8. Clinical characteristics of an allergic reaction to a polyether dental impression material.

    Science.gov (United States)

    Rafael, Caroline Freitas; Liebermann, Anja

    2017-04-01

    Allergic and hypersensitivity reactions to dental impression materials may occur throughout dental treatment, with diverse manifestations from slight redness to severe pain and a burning mouth with total stomatitis. Patients are often unaware of these allergic reactions, which makes early identification of the cause almost impossible. In addition, symptoms usually begin after 24 hours and mostly in patients with a preexisting history of allergic responses. This report describes a patient with a suspected allergic reaction to a polyether dental impression material during prosthetic rehabilitation associated with a mandibular telescopic denture. Although instances of such occurrence are rare, clinicians need to be aware of these symptoms and select materials carefully for patients with a history of allergy. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  9. In vitro comparative evaluation of mechanical properties of temporary restorative materials used in fixed partial denture

    Directory of Open Access Journals (Sweden)

    D Saisadan

    2016-01-01

    Full Text Available Introduction: Materials used to fabricate provisional restorations can be classified as acrylics or resin composites. Provisional crows can be either prefabricated or custom made. Acrylics: These materials have been used to fabricate provisional restorations since the 1930s and usually available as powder and liquid. They are the most commonly used materials today for both single-unit and multiple-unit restorations. In general, their popularity is due to their low cost, acceptable esthetics, and versatility. Composites: Composite provisional materials use bis-acryl resin, a hydrophobic material that is similar to bis-GMA. Composites are available as auto-polymerized, dualpolymerized and visible light polymerized. Preformed Crowns: Preformed provisional crowns or matrices usually consist of tooth-shaped shells of plastic, cellulose acetate or metal. They are commercially available in various tooth sizes and are usually selected for a particular tooth anatomy. They are commonly relined with acrylic resin to provide a more custom fit before cementation, but the plastic and metal crown shells can also be cemented directly onto prepared teeth. Aims and Objectives: The aim of this study is to choose a material to serve as a better interim prosthesis and to compare three different properties – flexural strength, compressive strength, and color stability. Materials and Methods: The samples were made with three different provisional materials (Revotek LC, Protemp 4, TemSpan. Result: It was inferred from the study that no one material was superior in all three tested parameters.

  10. Biological effects of radiation from dental radiography. Council on Dental Materials, Instruments, and Equipment

    International Nuclear Information System (INIS)

    Gibbs, S.J.

    1982-01-01

    Clearly, there is ample evidence of adverse effects of radiation in sufficient doses. There is at present no proof of such effects from doses commonly employed in dental practice; however, it has not been possible to prove the absence of such effects. Most experts now agree that there may be a small, difficult to quantify risk of cancer or genetic mutation from diagnostic exposure in patients and in personnel exposed during work. Prudence dictates acceptance of this position until proof to the contrary is available. This report has presented recent attempts to quantify the risk to patients based on speculative calculations and extrapolations. Indices of population risks indicate that medical radiology is the largest source of human-made genetic and leukemogenic radiation burden to the American public. Dental radiology contributes a small-but not necessarily insignificant-portion. Of major concern is the increasing use of radiation for diagnostic purposes in both medicine and dentistry. Technological advances have reduced exposure per examination; presumably this trend will continue so that total exposure of populations to radiation in the healing arts will not increase. Recent analyses suggest that the cancer risk to a patient from a dental radiographic examination is of the order of one in a million; the genetic risk is substantially less, about one in a billion. The risks appear to be essentially equal for full-mouth intraoral and for panoramic examinations. These estimates are numerically quite small, but the effects are severe. Thus, these risks cannot be ignored. However, we currently accept risks of similar magnitude in our daily lives [Table 9]50,51 In addition, the risk of failure to make an accurate diagnosis may be greater than the risk from exposure to the radiation from a justified and properly conducted radiographic examination

  11. Own brand label restorative materials-A false bargain?

    Science.gov (United States)

    Johnsen, Gaute Floer; Thieu, Minh Khai Le; Hussain, Badra; Pamuła, Elzbieta; Reseland, Janne Elin; Lyngstadaas, Ståle Petter; Haugen, Håvard

    2017-01-01

    This study aims at evaluating and comparing mechanical, chemical, and cytotoxicological parameters of a commercial brand name composite material against two 'own brand label' (OBL) composites. Parameters included depth of cure, flexural strength, degree of conversion, polymerization shrinkage, filler particle morphology and elemental analyzes, Vickers hardness, surface roughness parameters after abrasion, monomer elution, and cytotoxicity. The conventional composite outperformed the OBLS in terms of depth of cure (pbrand-name composites, but at a lower price. Dentists are highly recommended to reconsider utilization of OBLs lacking sound scientific scrutiny, and our findings underscore this recommendation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Bulletin of Materials Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Dental composites are tooth-coloured restorative material used by dentists for various applications. Restoration of a lost tooth structure requires a material having mechanical as well as aesthetic properties similar to that of tooth. This poses challenges to engineers and the dentist alike. Dental composites consist of a matrix ...

  13. In vitro comparative evaluation of mechanical properties of temporary restorative materials used in fixed partial denture.

    Science.gov (United States)

    Saisadan, D; Manimaran, P; Meenapriya, P K

    2016-10-01

    Materials used to fabricate provisional restorations can be classified as acrylics or resin composites. Provisional crows can be either prefabricated or custom made. These materials have been used to fabricate provisional restorations since the 1930s and usually available as powder and liquid. They are the most commonly used materials today for both single-unit and multiple-unit restorations. In general, their popularity is due to their low cost, acceptable esthetics, and versatility. Composite provisional materials use bis-acryl resin, a hydrophobic material that is similar to bis-GMA. Composites are available as auto-polymerized, dualpolymerized and visible light polymerized. Preformed provisional crowns or matrices usually consist of tooth-shaped shells of plastic, cellulose acetate or metal. They are commercially available in various tooth sizes and are usually selected for a particular tooth anatomy. They are commonly relined with acrylic resin to provide a more custom fit before cementation, but the plastic and metal crown shells can also be cemented directly onto prepared teeth. The aim of this study is to choose a material to serve as a better interim prosthesis and to compare three different properties - flexural strength, compressive strength, and color stability. The samples were made with three different provisional materials (Revotek LC, Protemp 4, TemSpan). It was inferred from the study that no one material was superior in all three tested parameters.

  14. Coronal microleakage of four temporary restorative materials in Class II-type endodontic access preparations

    Directory of Open Access Journals (Sweden)

    Sang-Mi Yun

    2012-02-01

    Full Text Available Objectives The purpose of this study was to evaluate the microleakage of 4 temporary materials in teeth with Class II-type endodontic access preparations by using a glucose penetration model. Materials and Methods Glucose reaction test was performed to rule out the presence of any reaction between glucose and temporary material. Class II-type endodontic access preparations were made in extracted human premolars with a single root (n = 10. Each experimental group was restored with Caviton (GC, Spacer (Vericom, IRM (Dentsply-Caulk, or Fuji II(GC. Microleakage of four materials used as temporary restorative materials was evaluated by using a glucose penetration model. Data were analyzed by the one-way analysis of variance followed by a multiple-comparison Tukey test. The interface between materials and tooth were examined under a scanning electron microscope (SEM. Results There was no significant reaction between glucose and temporary materials used in this study. Microleakage was significantly lower for Caviton and Spacer than for Fuji II and IRM. SEM observation showed more intimate adaptation of tooth-restoration interfaces in Caviton and Spacer than in IRM and Fuji II. Conclusions Compared to IRM and Fuji II, Caviton and Spacer can be considered better temporary sealing materials in Class II-type endodontic access cavities.

  15. Highly-translucent, strong and aging-resistant 3Y-TZP ceramics for dental restoration by grain boundary segregation.

    Science.gov (United States)

    Zhang, Fei; Vanmeensel, Kim; Batuk, Maria; Hadermann, Joke; Inokoshi, Masanao; Van Meerbeek, Bart; Naert, Ignace; Vleugels, Jef

    2015-04-01

    Latest trends in dental restorative ceramics involve the development of full-contour 3Y-TZP ceramics which can avoid chipping of veneering porcelains. Among the challenges are the low translucency and the hydrothermal stability of 3Y-TZP ceramics. In this work, different trivalent oxides (Al2O3, Sc2O3, Nd2O3 and La2O3) were selected to dope 3Y-TZP ceramics. Results show that dopant segregation was a key factor to design hydrothermally stable and high-translucent 3Y-TZP ceramics and the cation dopant radius could be used as a controlling parameter. A large trivalent dopant, oversized as compared to Zr(4+), exhibiting strong segregation at the ZrO2 grain boundary was preferred. The introduction of 0.2 mol% La2O3 in conventional 0.1-0.25 wt.% Al2O3-doped 3Y-TZP resulted in an excellent combination of high translucency and superior hydrothermal stability, while retaining excellent mechanical properties. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  16. Anesthetic management of comprehensive dental restoration in a child with glutaric aciduria type 1 using volatile sevoflurane

    Directory of Open Access Journals (Sweden)

    Wei-Nung Teng

    2014-10-01

    Full Text Available Glutaric aciduria type 1 (GA1 is a rare, inherited mitochondrial disorder that results from deficiency of mitochondrial glutaryl-CoA dehydrogenase. Most patients develop neurological dysfunction early in life, which leads to severe disabilities. We present a 37-month-old girl with GA1 manifested as macrocephaly and hypotonia who received comprehensive dental restoration surgery under general anesthesia with sevoflurane. She was placed on specialized fluid management during a preoperative fasting period and anesthesia was administered without complications. All the physiological parameters, including glucose and lactate blood levels and arterial blood gas were carefully monitored and maintained within normal range perioperatively. Strategies for anesthetic management should include prevention of pulmonary aspiration, dehydration, hyperthermia and catabolic state, adequate analgesia to minimize surgical stress, and avoidance of prolonged neuromuscular blockade. We administered general anesthesia with sevoflurane uneventfully, which was well tolerated by our patient with GA1. Additionally, communication with a pediatric geneticist and surgeons should be undertaken to formulate a comprehensive anesthetic strategy in these patients.

  17. A resin composite material containing an eugenol derivative for intracanal post cementation and core build-up restoration.

    Science.gov (United States)

    Almaroof, A; Rojo, L; Mannocci, F; Deb, S

    2016-02-01

    To formulate and evaluate new dual cured resin composite based on the inclusion of eugenyl methacrylate monomer (EgMA) with Bis-GMA/TEGDMA resin systems for intracanal post cementation and core build-up restoration of endodontically treated teeth. EgMA was synthesized and incorporated at 5% (BTEg5) or 10% (BTEg10) into dual-cure formulations. Curing properties, viscosity, Tg, radiopacity, static and dynamic mechanical properties of the composites were determined and compared with Clearfil™DC Core-Plus, a commercial dual-cure, two-component composite. Statistical analysis of the data was performed with ANOVA and the Tukey's post-hoc test. The experimental composites were successfully prepared, which exhibited excellent curing depths of 4.9, 4.7 and 4.2 mm for BTEg0, BTEg5 and BTEg10 respectively, which were significantly higher than Clearfil™DC. However, the inclusion of EgMA initially led to a lower degree of cure, which increased when measured at 24 h with values comparable to formulations without EgMA, indicating post-curing. The inclusion of EgMA also lowered the polymerization exotherm thereby reducing the potential of thermal damage to host tissue. Both thermal and viscoelastic analyses confirmed the ability of the monomer to reduce the stiffness of the composites by forming a branched network. The compressive strength of BTEg5 was significantly higher than the control whilst flexural strength increased significantly from 95.9 to 114.8 MPa (BTEg5) and 121.9 MPa (BTEg10). Radiopacity of the composites was equivalent to ∼3 mm Al allowing efficient diagnosis. The incorporation of EgMA within polymerizable formulations provides a novel approach to prepare reinforced resin composite material for intracanal post cementation and core build-up and the potential to impart antibacterial properties of eugenol to endodontic restorations. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  18. Legal analysis of information displayed on dental material packages: An exploratory research

    Directory of Open Access Journals (Sweden)

    Bhumika Rathore

    2016-01-01

    Full Text Available Introduction: Some of the dental materials possess occupational hazards, preprocedural errors, and patient allergies as suggested by evidence. With due consideration to safety of the patients and dental professionals, it is essential that the trade of these materials is in conformity with the law. Aim: To perform the legal analysis of the information displayed on the packaging of dental materials. Materials and Methods: The Bureau of Indian Standards sets guidelines for packaging and marketing of dental products in India. An exploratory cross-sectional study was performed using various search engines and websites to access the laws and regulations existing pertaining to dental materials packaging. Based on the data obtained, a unique packaging standardization checklist was developed. Dental laboratory and impression plasters, alginates, and endodontic instruments were surveyed for all the available brands. This study considered 16 brands of plasters and alginates and 42 brands of endodontic instruments for legal analysis. Legal analysis was performed using the direct observation checklist. Descriptive statistics were obtained using SPSS version 19. Results: The guidelines set by the Bureau of Indian Standards do exist but are not updated and stand as oblivious guards for marketing standards. Overall compliance to the guidelines was reported to be 18.5% by brands of alginates, 4.1% by plaster of Paris, and 11.11% by endodontic instruments. Wave One™ File reported maximum adherence with the guidelines as 66.7%. Conclusion: This study found lower rate of adherence to the guidelines, thus indicating insufficient information being disclosed to the consumers.

  19. Effect of nightguard vital bleaching gel on the color stability of provisional restorative materials.

    Science.gov (United States)

    Bajunaid, Salwa Omar

    2016-01-01

    To assess the hypothesis that there was no difference in effect of 10% and 15% tooth bleaching agents on color stability of materials used for provisional fixed dental prosthesis. Fifteen samples from two materials used for provisional fixed dental prosthesis: methacrylate-based and composite-based materials and 15 preformed polycarbonate crowns soaked in bleaching gel or distilled water. Spectrophotometer recorded color of specimens at baseline, after 3, 7, and 14 days. Data were statistically analyzed using two-factor ANOVA test to compare the color stability of tested materials. Methyl-based provisional material exhibited statistically higher color change when exposed to 10% and 15% bleaching gel (delta EFNx01: 9.0 and 11.1, respectively) as compared to distilled water (delta EFNx01: 2.9). Delta EFNx01 of composite-based material specimens exposed to distilled water was statistically higher (6.3) than specimens exposed to 10% and 15% bleaching gel (1.5 and 1.1, respectively). Polycarbonate crowns showed a statistically lower color change when exposed to 15% (0.9) than to 10% bleaching gel (5.1) or distilled water (5.5). Composite-based provisional material showed highest color stability when exposed to vital tooth bleaching gel, whereas methacrylate-based material was the least color stable. Polycarbonate crowns were more color stable when exposed to 15% bleaching gel as opposed to 10% bleaching gel.

  20. Alternative materials study for dental magnetics attachments applications

    International Nuclear Information System (INIS)

    Marques, Rogerio Albuquerque

    2009-01-01

    Ferromagnetic alloys have been investigated as potential candidates for dental prosthesis applications in replacement for magnetic attachments made of noble and expensive alloys. Three stainless steels were investigated: 17-4 PH produced by powder injection (PIM), PM2000 obtained by mechanical alloying and oxide dispersion strengthened, and nickel free stainless steel 1802. In the in vitro cytotoxicity analysis, none of the three steels tested showed cytotoxic effects. The corrosion resistance of stainless steels was evaluated by electrochemical impedance spectroscopy (EIS) and anodic potentiodynamic polarization, in sodium phosphate buffer solutions (PBS) at 25 degree C. The AISI 316L stainless steel was also tested under the same conditions for comparison reasons. All the stainless steel samples were passive in the electrolyte used and presented susceptibility to pitting. The steel that showed the highest pitting resistance was the PM2000, whereas the 1802 had the lowest resistance to pitting among the tested ones. The Mott-Schottky diagrams suggested that the passive film over the surface of PM2000 steel is at least one decade less doped compared to 316L stainless steel, so less defective in its structure. The results pointed out to the PM2000 as a potential candidate for substitution of high cost magnetic alloys used in dental prosthesis. (author)

  1. In vitro comparison of coronal microleakage of four temporary restorative materials used in endodontic treatment

    Directory of Open Access Journals (Sweden)

    Shahi Sh.

    2008-10-01

    Full Text Available "nBackground and Aim: The use of proper temporary restorative materials between appointments is critical in successful root canal treatment. The purpose of this study was to compare the coronal microleakage of four temporary restorative materials including Zonalin, Zamherir, Coltosol and IRM. "nMaterials and Methods: In this in vitro study, standard access cavities were prepared in 120 intact extracted maxillary and mandibular human first molars. Canal preparation was carried out by the step-back technique, and obturation was performed with gutta-percha and AH26 sealer using the lateral condensation technique. Teeth were randomly divided into 4 experimental groups of 25 teeth each and two positive and negative control groups, each containing 10 teeth. In each experimental group the access cavity was restored with one of the tested materials (Zamherir, Zonalin, IRM and Coltosol. In the negative control group the access cavity was filled entirely with sticky wax and in the positive control group no restorative material was applied. Dye penetration technique was used to evaluate microleakage which was measured under a stereomicroscope. Data were analyzed with one way ANOVA and post hoc Tukey tests. P<0.05 was considered as the limit of significance. "nResults: Dye penetration was observed in all groups. Zonalin and Coltosol had the highest and the lowest dye penetration respectively, with a statistically significant difference (p<0.001. There was no significant difference in dye penetration between IRM, and either Coltosol or Zamherir (p>0.05. "nConclusion: The results of this study showed that using Coltosol as a temporary restorative material can provide a better coronal seal in endodontic treatments

  2. Study of filling material of dental composites. An analytical approach using radio-activation

    Energy Technology Data Exchange (ETDEWEB)

    Eke, Canel [Akdeniz Univ., Antalya (Turkey). Nuclear Sciences Application and Research Center; Akdeniz Univ., Antalya (Turkey). Div. of Physics Education; Er, Kursat [Akdeniz Univ., Antalya (Turkey). Dept. of Endodontics; Segebade, Christian [Akdeniz Univ., Antalya (Turkey). Nuclear Sciences Application and Research Center; Boztosun, Ismail [Akdeniz Univ., Antalya (Turkey). Nuclear Sciences Application and Research Center; Akdeniz Univ., Antalya (Turkey). Dept. of Physics

    2018-04-01

    The aim of this study is to carry out elemental analyses of dental composites acquired from different producers using photoactivation analysis (PAA). High energy electrons produced by an electron linear accelerator are absorbed by a tungsten disk (Bremsstrahlung converter) thereby producing high energy X-rays (bremsstrahlung). The dental composite materials under study were exposed to the bremsstrahlung radiation whereby radionuclides were produced through photonuclear reactions. Their radioactivities were measured using high resolution semiconductor spectrometers equipped with high purity germanium detectors (HPGe). The spectra were analysed using appropriate computer software. As a result, photonuclear reactions of 12 stable elements were detected in different dental composite species, and the elemental concentrations were calculated. For comparison, the dental composites were also investigated using scanning electron microscopy (SEM) and energy-dispersive X-ray fluorescence spectrometry (EDXRF). Various sizes and shapes of dental composites were observed using SEM. However, contents of dental composites, e.g. Mg, Ni, Ba and Sr were obtained by PAA whilst C, O, Al, S, Ba and Sr were detected by EDXRF spectrometry. The results for Ba and Sr obtained using the two techniques show considerable difference.

  3. Dematerialization of the Ruins : Glass as a Promising Restorative Material for the Consolidation of Historic Structures

    NARCIS (Netherlands)

    Barou, L.; Oikonomopoulou, F.; Bristogianni, T.; Veer, F.A.; Nijsse, R.; Louter, Christian; Bos, Freek; Belis, Jan; Veer, Fred; Nijsse, Rob

    This research investigates the potential of glass as a new design tool to highlight and safeguard our historic structures. Current restoration and conservation treatments with traditional materials bear the risk of conjecture between the original and new elements, whereas the high consolidation

  4. A strategy for maximizing native plant material diversity for ecological restoration, germplasm conservation and genecology research

    Science.gov (United States)

    Berta Youtie; Nancy Shaw; Matt Fisk; Scott Jensen

    2012-01-01

    One of the most important steps in planning a restoration project is careful selection of ecologically adapted native plant material. As species-specific seed zone maps are not available for most species in the Artemisia tridentata ssp. wyomingensis (Wyoming big sagebrush) ecoregion in the Great Basin, USA, we are employing a provisional seed zone map based on annual...

  5. Dental Cements for Luting and Bonding Restorations: Self-Adhesive Resin Cements.

    Science.gov (United States)

    Manso, Adriana P; Carvalho, Ricardo M

    2017-10-01

    Self-adhesive resin cements combine easy application of conventional luting materials with improved mechanical properties and bonding capability of resin cements. The presence of functional acidic monomers, dual cure setting mechanism, and fillers capable of neutralizing the initial low pH of the cement are essential elements of the material and should be understood when selecting the ideal luting material for each clinical situation. This article addresses the most relevant aspects of self-adhesive resin cements and their potential impact on clinical performance. Although few clinical studies are available to establish solid clinical evidence, the information presented provides clinical guidance in the dynamic environment of material development. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Evaluation of simulation learning materials use to fill the gap in Japanese dental English education.

    Science.gov (United States)

    Seki, Naoko; Moross, Janelle; Sunaga, Masayo; Hobo, Koki; Miyoshi, Tomoe; Nitta, Hiroshi; Kinoshita, Atsuhiro; Morio, Ikuko

    2016-01-01

    Even though English is most frequently the common language when the patient's native language differs from that of a dentist, the opportunities for Japanese undergraduate dental students to learn dental English are now quite limited. The purposes of our study were to investigate: the effectiveness and feasibility of the computer-assisted simulation materials as one solution strategy for dental English education in Japan, and the needs and demands for dental English from the learners' side. Interactive simulation materials for medical interviews in English and clinical cases which were translated to English, were delivered via Learning Management System (LMS) to nineteen trainee residents of dentistry (residents). Evaluation for the materials, learners' knowledge and interests in the contents, and ease of operation were obtained by post-questionnaire (response rates were 100% and 95%, respectively). Both questionnaire-surveys received positive feedback toward the materials, yet 47% answered that they lacked the level of knowledge about contents of the medical interview in English. Results were sufficient to suggest that the residents would like to have the opportunity to study or practice medical interview in English, or English related to dentistry, and that the simulation materials could be one of the solution strategies for opportunity provision.

  7. RESTORING A DAMAGED 16-YEAR -OLD INSULATING POLYMER CONCRETE DIKE OVERLAY: REPAIR MATERIALS AND TECHNOLOGIES.

    Energy Technology Data Exchange (ETDEWEB)

    SUGAMA,T.

    2007-01-01

    The objective of this program was to design and formulate organic polymer-based material systems suitable for repairing and restoring the overlay panels of insulating lightweight polymer concrete (ILPC) from the concrete floor and slope wall of a dike at KeySpan liquefied natural gas (LNG) facility in Greenpoint, Brooklyn, NY, just over sixteen years ago. It also included undertaking a small-scale field demonstration to ensure that the commercial repairing technologies were applicable to the designed and formulated materials.

  8. Effect of dental materials on gluconeogenesis in rat kidney tubules

    Energy Technology Data Exchange (ETDEWEB)

    Reichl, F.X.; Durner, J.; Mueckter, H.; Elsenhans, B.; Forth, W. [Muenchen Univ. (Germany). Walter-Straub-Institut fuer Pharmakologie und Toxikologie; Kunzelmann, K.H.; Hickel, R. [Department of Operative/Restorative Dentistry, Periodontology and Pedodontics, Ludwig-Maximilians-University of Munich (Germany); Spahl, W. [Institute of Organic Chemistry, Ludwig-Maximilians-University of Munich (Germany); Hume, W.R. [Dental Research Institute, Univ. of California, Los Angeles, CA (United States); Moes, G.W. [TNO Prins-Maurits-Laboratorium, Rijswijk (Netherlands)

    1999-09-01

    The effect of dental composite components triethyleneglycoldimethacrylate (TEGDMA) and hydroxyethylmethacrylate (HEMA) as well as mercuric chloride (HgCl{sub 2}) and methylmercury chloride (MeHgCl) on gluconeogenesis was investigated in isolated rat kidney tubules. From starved rats kidney tubules were prepared and isolated by digestion with collagenase. Every 10 min up to 60 min 1-ml samples were drawn from the cell suspension for quantitating the glucose content. Glucose formation in controls was 3.3 {+-} 0.2 nmol/mg . per min (mean {+-} SEM, n=21). Relative rates of glucose formation were obtained by expressing individual rates as a percentage of the corresponding control. X-Y concentration curves (effective concentration, EC) of the substances were calculated by fitting a four-parametric sigmoid function to the relative rates of glucose formation at various test concentrations. At the end of the incubation period cell viability was assessed by trypan blue exclusion. Cell viability decreased within the 60 min interval from 90 to approx. 80% (controls), <25 (HEMA), <20 (TEGDMA), <10 (MeHgCl), and <10% (HgCl{sub 2}). Values of 50% effective concentration (EC{sub 50}) were calculated from fitted curves. EC{sub 50} values were (mmol; mean {+-} SEM; n=4): HEMA, 17.7 {+-} 2.9; TEGDMA, 1.8 {+-} 0.2; MeHgCl, 0.018 {+-} 0.0005; and HgCl{sub 2}, 0.0016 {+-} 0.0005. The toxic effect of HgCl{sub 2} was {proportional{underscore}to}1000 or 10 000 higher than that of the dental composite components TEGDMA or HEMA, respectively. (orig.)

  9. Evaluation of mechanical and optical behavior of current esthetic dental restorative CAD/CAM composites.

    Science.gov (United States)

    Stawarczyk, Bogna; Liebermann, Anja; Eichberger, Marlis; Güth, Jan-Frederik

    2015-03-01

    To determine the mechanical and optical properties of CAD/CAM composites (LAVA Ultimate, Cerasmart, Shofu Block and two exp. CAD/CAM composites), a hybrid material (VITA Enamic), a leucite (IPS Empress CAD) and a lithium disilicate glass-ceramic (IPS e.max CAD). Three-point flexural strength (FS) was investigated according ISO 6872:2008 (N=240/n=30). Two-body wear (TBW) was analyzed in a chewing simulator (1,200,000 cycles, 50N, 5°/55°C) using human teeth as antagonists (N=120/n=15). Quantitative analysis of wear was carried out with a 3D-scanner and associated matching software. Discoloration rate (DR) after 14 days of storage in cress, curry, red wine, and distilled water (N=384/n=12), and translucency (T) (N=384/n=48) of CAD/CAM materials were measured in a spectrophotometer (400-700nm wavelength). Data were analyzed using two-/one-way ANOVA with Scheffé post-hoc test, Kruskal-Wallis-H test, and linear mixed models (α=0.05). IPS e.max CAD showed the highest FS (pCAD/CAM composites (exception: Shofu Block). The lowest FS showed VITA Enamic and IPS Empress CAD (pCAD, VITA Enamic, exp. CAD/CAM composite 2, followed by IPS e.max presented lower material TBW than the remaining CAD/CAM materials (pcurry>cress>distilled water) exerted the highest influence on DR (pCAD/CAM material. Glass-ceramics showed lower DR than CAD/CAM composites (pCAD/CAM composites presented moderate FS, high T and antagonist friendly behavior. Glass-ceramic demonstrated the most favorable DR and lowest TBW on the material side. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Microstructure Images Restoration of Metallic Materials Based upon KSVD and Smoothing Penalty Sparse Representation Approach.

    Science.gov (United States)

    Li, Qing; Liang, Steven Y

    2018-04-20

    Microstructure images of metallic materials play a significant role in industrial applications. To address image degradation problem of metallic materials, a novel image restoration technique based on K-means singular value decomposition (KSVD) and smoothing penalty sparse representation (SPSR) algorithm is proposed in this work, the microstructure images of aluminum alloy 7075 (AA7075) material are used as examples. To begin with, to reflect the detail structure characteristics of the damaged image, the KSVD dictionary is introduced to substitute the traditional sparse transform basis (TSTB) for sparse representation. Then, due to the image restoration, modeling belongs to a highly underdetermined equation, and traditional sparse reconstruction methods may cause instability and obvious artifacts in the reconstructed images, especially reconstructed image with many smooth regions and the noise level is strong, thus the SPSR (here, q = 0.5) algorithm is designed to reconstruct the damaged image. The results of simulation and two practical cases demonstrate that the proposed method has superior performance compared with some state-of-the-art methods in terms of restoration performance factors and visual quality. Meanwhile, the grain size parameters and grain boundaries of microstructure image are discussed before and after they are restored by proposed method.

  11. The performance of human dental pulp stem cells on different three-dimensional scaffold materials.

    NARCIS (Netherlands)

    Zhang, W.; Walboomers, X.F.; Kuppevelt, A.H.M.S.M. van; Daamen, W.F.; Bian, Z.; Jansen, J.A.

    2006-01-01

    The aim of this study was to investigate the in vitro and in vivo behavior of human dental pulp stem cells (DPSCs) isolated from impacted third molars, when seeded onto different 3-dimensional (3-D) scaffold materials: i.e. a spongeous collagen, a porous ceramic, and a fibrous titanium mesh.

  12. 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

  13. Monitoring the restoration of interfacial contact for self healing thermal interface materials for LED and microelectronic applications

    NARCIS (Netherlands)

    Lafont, U.L.; Van Zeijl, H.W.; Van der Zwaag, S.

    2013-01-01

    While conventional self healing materials focus on the restoration of mechanical properties, newer generations of self healing materials focus on the restoration of other functional (i.e. non-mechanical) properties. Thermal conductivity is an example of an important functional property of a Thermal

  14. Some aspects of the formulation of alginate dental impression materials--setting characteristics and mechanical properties.

    Science.gov (United States)

    Nallamuthu, Navina A; Braden, Michael; Patel, Mangala P

    2012-07-01

    To study the role of the various components of alginate dental impression materials. Experimental materials were formulated and their physical properties characterized and compared to commercially available counterparts (Neocolloid, Palgat Plus and Blueprint Cremix). Properties examined were: dimensional stability and weight change in water and artificial saliva; setting behavior; Shore A hardness and tear energy. The role of magnesium oxide was also investigated. Weight changes in water and artificial saliva can be attributed to an initial thermodynamic potential owing to the ionic content of the alginate, causing water to diffuse into the material. Water is then driven back out following a reversal of this potential. Hardness results for experimental materials were within the range obtained from the commercial materials. The hardness value for an experimental formulation that did not contain magnesium oxide was lower than values from the other experimental materials that did. Tear energies for all three experimental materials were greater than those of the commercial products. There were statistically significant differences between the two experimental materials that contained magnesium oxide and one that did not. With regard to setting time, statistically significant differences were seen between commercial materials and two of the experimental materials. The experimental material that did not contain magnesium oxide had a considerably longer setting time than all of the other materials tested. The key role of magnesium oxide in the setting reaction and the effect on hardness have been demonstrated and discussed. Copyright © 2012 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  15. Equity in children's dental caries before and after cessation of community water fluoridation: differential impact by dental insurance status and geographic material deprivation.

    Science.gov (United States)

    McLaren, Lindsay; McNeil, Deborah A; Potestio, Melissa; Patterson, Steve; Thawer, Salima; Faris, Peter; Shi, Congshi; Shwart, Luke

    2016-02-11

    One of the main arguments made in favor of community water fluoridation is that it is equitable in its impact on dental caries (i.e., helps to offset inequities in dental caries). Although an equitable effect of fluoridation has been demonstrated in cross-sectional studies, it has not been studied in the context of cessation of community water fluoridation (CWF). The objective of this study was to compare the socio-economic patterns of children's dental caries (tooth decay) in Calgary, Canada, in 2009/10 when CWF was in place, and in 2013/14, after it had been discontinued. We analyzed data from population-based samples of schoolchildren (grade 2) in 2009/10 and 2013/14. Data on dental caries (decayed, missing, and filled primary and permanent teeth) were gathered via open mouth exams conducted in schools by registered dental hygienists. We examined the association between dental caries and 1) presence/absence of dental insurance and 2) small area index of material deprivation, using Poisson (zero-inflated) and logistic regression, for both time points separately. For small-area material deprivation at each time point, we also computed the concentration index of inequality for each outcome variable. Statistically significant inequities by dental insurance status and by small area material deprivation were more apparent in 2013/14 than in 2009/10. Results are consistent with increasing inequities in dental caries following cessation of CWF. However, further research is needed to 1) confirm the effects in a study that includes a comparison community, and 2) explore possible alternative reasons for the findings, including changes in treatment and preventive programming.

  16. Influence of curing time, overlay material and thickness on three light-curing composites used for luting indirect composite restorations.

    Science.gov (United States)

    D'Arcangelo, Camillo; De Angelis, Francesco; Vadini, Mirco; Carluccio, Fabio; Vitalone, Laura Merla; D'Amario, Maurizio

    2012-08-01

    To assess the microhardness of three resin composites employed in the adhesive luting of indirect composite restorations and examine the influence of the overlay material and thickness as well as the curing time on polymerization rate. Three commercially available resin composites were selected: Enamel Plus HRI (Micerium) (ENA), Saremco ELS (Saremco Dental) (SAR), Esthet-X HD (Dentsply/DeTrey) (EST-X). Post-polymerized cylinders of 6 different thicknesses were produced and used as overlays: 2 mm, 3 mm, 3.5 mm, 4 mm, 5 mm, and 6 mm. Two-mm-thick disks were produced and employed as underlays. A standardized amount of composite paste was placed between the underlay and the overlay surfaces which were maintained at a fixed distance of 0.5 mm. Light curing of the luting composite layer was performed through the overlays for 40, 80, or 120 s. For each specimen, the composite to be cured, the cured overlay, and the underlay were made out of the same batch of resin composite. All specimens were assigned to three experimental groups on the basis of the resin composite used, and to subgroups on the basis of the overlay thickness and the curing time, resulting in 54 experimental subgroups (n = 5). Forty-five additional specimens, 15 for each material under investigation, were produced and subjected to 40, 80, or 120 s of light curing using a microscope glass as an overlay; they were assigned to 9 control subgroups (n = 5). Three Vicker's hardness (VH) indentations were performed on each specimen. Means and standard deviations were calculated. Data were statistically analyzed using 3-way ANOVA. Within the same material, VH values lower than 55% of control were not considered acceptable. The used material, the overlay thickness, and the curing time significantly influenced VH values. In the ENA group, acceptable hardness values were achieved with 3.5-mm or thinner overlays after 120 or 80 s curing time (VH 41.75 and 39.32, respectively), and with 2-mm overlays after 40 s (VH 54

  17. Coronal microleakage with five different temporary restorative materials following walking bleach technique: An ex-vivo study

    Directory of Open Access Journals (Sweden)

    G. P. V Srikumar

    2012-01-01

    Full Text Available Context: Walking bleach technique uses 30% hydrogen peroxide and sodium perborate, and this paste mixture causes loosening of the coronal temporary restorative materials and thus decreasing its clinical effectiveness and causing irritation to the patients oral tissues. In the present study, sealing ability of hygroscopic coronal temporary restorative materials were compared with the other commonly used temporary restorative materials. Aim: To evaluate the effects of walking bleach material on the marginal sealing ability and coronal microleakage of the hydrophilic temporary restorative materials with that of the other commonly used temporary restorative materials in endodontic practice. Materials and Methods: Seventy-five extracted human maxillary central incisor teeth were prepared chemo-mechanically and obturated with gutta-percha in lateral condensation technique. Surface of each tooth was double coated with cyanoacrylate glue. All the teeth were randomly divided in to five groups. Out of 15 teeth in each group, 10 teeth served as experimental specimens, in which bleaching agent was placed in the pulp chamber and 5 teeth served as control, in which no bleaching agent was placed. The access cavities were restored with temporary restorative materials being tested per each group respectively. The specimens were then immersed in 1% India ink dye and subjected to thermo cycling for 7 days. All the teeth were longitudinally sectioned and observed with stereomicroscope and were graded according to the depth of linear dye penetration. Statistical Analysis Used: Mann-Whitney U test and Kruskal-Wallis test. Results: Hydrophilic temporary restorative materials Cavit G and Coltosol F have shown minimal coronal dye leakage with better sealing ability when exposed to walking bleach paste mixture in the dye penetration tests compared to other commonly used temporary restorative materials. Conclusion: Marginal sealing ability of Cavit G and Coltosol F were

  18. Effect of two different bleaching regimens on the gloss of tooth colored restorative materials.

    Science.gov (United States)

    Yalcin, Filiz; Gürgan, Sevil

    2005-05-01

    Vital tooth bleaching with peroxide is one of the most common cosmetic procedures in dentistry and can be accomplished using a variety of methods or regimens. Recently, new generation of tooth color restorative materials were introduced to market. The purpose of this in vitro study was to determine the gloss changes of three different tooth color restorative materials: Flowable composite (Filtek Flow/3M), packable composite (Filtek P60/3M) and ormocer (Definite/DEGUSSA) after two different bleaching regimens (Vivastyle/VIVADENT) and (Crest Professional Whitestrips/PROCTER and GAMBLE). 16 specimens 30 x 30 x 2 mm size were fabricated from each restorative material. After gloss values were measured with gloss meter, at two different angles of illumination (20 and 60 degrees ), 10% carbamide peroxide (Vivastyle) was applied for 2 h per day for fourteen days to the half of the specimens while 6.5% hydrogen peroxide strip bands (Crest Professional Whitestrips) were applied to the remaining eight of the specimens for 30 min twice daily for 14 days. During the test period the specimens were stored in 37 degrees C and 100% relative humidity. At the end of bleaching regimen the gloss measurements were repeated and the data were subjected to statistical analysis. The Wilcoxon Signed Rank Test analysis revealed that the gloss values were affected by both bleaching regimens (P=0.012). Whitestrips decreased the gloss values of Filtek P60 (at 20 and 60 degrees , Pgloss values of Definite did not show any significant change between Vivastyle and Whitestrips application (at 20 degrees P=0.279; at 60 degrees , P=0.279, Mann-Whitney U Test). The gloss values of materials were significantly different before (at 20 degrees Pgloss of tooth colored restorative materials could be affected by bleaching regimens, it is necessary to consider the type of the material before starting the treatment.

  19. Occupational exposure to contaminated biological material: perceptions and feelings experienced among dental students

    Directory of Open Access Journals (Sweden)

    Camila PINELLI

    Full Text Available INTRODUCTION: Dental students may be a particularly vulnerable group exposed to the risk of acquiring infections through occupational injuries.OBJECTIVE: To investigate the perceptions with regard to their occupational exposure to potentially infectious biologic materials.MATERIAL AND METHOD: Interviews were conducted by means of a script with open questions. The speeches were recorded, transcribed and qualitative analysis was performed with the aid of QUALIQUANTISOFT® software. The Collective Subject Discourse (CSD was obtained.RESULT: The feeling most frequently experienced was related to the fear of contagion. Most accidents occurred during the handling of sharp dental instruments. Respondents attributed the occurrence of accidents especially the lack of attention, carelessness while handling sharp instruments, and lack of use of Personal Protective Equipment. As regards the measures taken right after the exposure, they "washed the local area". Other respondents reported they "continued the dental treatment". They complained mostly about the fear of having been infected, and because they had to leave the faculty to take blood exams for HIV screening. As part of the learning experience the injured reported they paid more attention when handling sharp instruments. The students informed that any type of injury due to contact with contaminated material must be notified. However, they were neglectful about reporting their own injury.CONCLUSION: Education strategies for preventive measures related to occupational exposure must be restructured, because the knowledge and the fear of contagion among dental students were not always sufficient for a complete adherence to treatment protocols and notification.

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

    Science.gov (United States)

    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.

  1. Clinical Bonding of Resin Nano Ceramic Restorations to Zirconia Abutments : A Case Series within a Randomized Clinical Trial

    NARCIS (Netherlands)

    Schepke, Ulf; Meijer, Henny J. A.; Vermeulen, Karin M.; Raghoebar, Gerry M.; Cune, Marco S.

    2016-01-01

    Background: New dental materials are introduced and promoted in the field without extensive clinical testing. Using those materials in a clinical setting might result in unacceptable early failure rates. Purpose: The purpose of this paper was to analyze bonding of a new dental restorative material

  2. Study of the luminescence properties of dental materials for their use in accidental dosimetry

    International Nuclear Information System (INIS)

    Veronese, Ivan; Cantone, Marie C.; Guzzi, Gianpaolo

    2008-01-01

    Full text: The current social and political situation in many world areas and the increasing hostilities between countries and cultures have accentuated the risk of a malicious use of ionising radiations. Terrorist attacks with the intentional disseminations of radioactive materials in urban settlements may involve a large number of persons, and a rapid estimation of the severity of the exposure is required for undertaking suitable protective actions and supporting decision making. Promising methodologies for a prompt dose evaluation, are those exploiting the luminescence and dosimetric properties of objects and materials which can be easily found in the contaminated area. Among these objects, dental materials have the advantage to be on contact with human body and they could therefore represent individual dosimeters in case of accidental exposure to ionising radiation. The interest in the use of dental ceramics for dosimetric purposes dates back to late 1970, however, it is only through the use of high-sensitive experimental techniques and instrumentation today available, that the potentiality of such materials as accidental dosimeters can be exploited. Moreover, innovative materials are being continuously introduced into the market, containing new additives and pigments with peculiar optical properties. In this study, Thermally Stimulated Luminescence (TSL) and Optically Stimulated Luminescence (OSL) techniques are applied to investigate the luminescence and dosimetric properties of several dental materials, including resins, glass and feldspatic ceramics, and also zirconia and alumina based ceramics, being their use widely increased in the recent years in substitution of metal cores. (author)

  3. ADVANCED CERAMIC MATERIALS FOR DENTAL APPLICATIONS SINTERED BY MICROWAVE HEATING

    OpenAIRE

    Presenda Barrera, Álvaro

    2016-01-01

    [EN] Zirconia has become a widely utilized structural ceramic material with important applications in dentistry due to its superb mechanical properties, biocompatibility, aesthetic characteristics and durability. Zirconia needs to be stabilized in the t-phase to obtain improved mechanical properties such as hardness and fracture toughness. Fully dense yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) materials are normally consolidated through the energy-intensive processing of po...

  4. The effect of different drinks on the color stability of different restorative materials after one month

    Directory of Open Access Journals (Sweden)

    Neslihan Tekçe

    2015-11-01

    Full Text Available Objectives The aim of this study was to evaluate the effect of three different drinks on the color parameters of four different restorative materials. Materials and Methods Three different composites (Filtek Ultimate Universal Restorative, Filtek Ultimate Flowable, and Filtek Silorane, 3M ESPE and a polyacid-modified composite resin material (Dyract XP, Dentsply DeTrey GmbH were evaluated. Eighty-four disc-shaped specimens of 8 mm in diameter and 2 mm in thickness were prepared (n = 21 each. Color coordinates (L*a*b*, ΔL*, Δa*, Δb*, and ΔE* were measured using a VİTA Easyshade Compact (VİTA Zahnfabrik after 24 hr of storage (baseline and after 30 day of storage in three different beverages of black tea, Coca cola, or water (control (n = 7. In each beverage, the specimens were stored three times a day, one hr each, for 30 day. The color changes (ΔE were calculated and were analyzed by Kruskal-Wallis and Dunn multiple comparison test. Results The color difference (ΔE* of the resin materials ranged between 1.31 and 15.28 after 30 day of immersion in the staining solutions. Dyract XP in Coca cola (15.28 ± 2.61 and black tea (12.22 ± 2.73 showed the highest mean ΔE* value after 30 day, followed by Filtek Ultimate Universal Restorative (5.99 ± 1.25 and Filtek Ultimate Flowable (4.71 ± 1.40 in black tea (p < 0.05. Conclusions The compomers displayed unacceptable color changes at the end of 30 day in all beverages. Among resin composites, the silorane based composite exhibited relatively good color stability than the others. Filtek Ultimate Universal Restorative and Filtek Flowable showed similar color changes in all beverages.

  5. Influence of light-curing units and restorative materials on the micro hardness of resin cements

    Directory of Open Access Journals (Sweden)

    Kuguimiya Rosiane

    2010-01-01

    Full Text Available Aim: The aim of this study was to evaluate the effect of indirect restorative materials (IRMs and light-curing units (LCUs on the micro hardness of dual-cured resin cement. Materials and Methods: A total of 36 cylindrical samples (2 mm thick were prepared with dual-cured resin cement (Relyx ARC photo-activated with either a QTH (Optilight Plus for 40s or a LED (Radii light-curing unit for 65s. Photo-activation was performed through the 2-mm- thick IRMs and the samples were divided into six groups (n=6 according to the combination of veneering materials (without, ceramic and indirect resin and LCUs (QTH and LED. In the control group, the samples were light-cured with a QTH unit without the interposition of any restorative material. Vickers micro hardness test was performed on the top and bottom surfaces of each sample (load of 50 g for 15 secs. The data were statistically analyzed using a three-way ANOVA followed by Tukey x s post-hoc test ( P < 0.05. Results: There were no statistically significant differences on the top surface between the light curing-units ( P > 0.05; however, the LED provided greater hardness on the bottom surface when a ceramic material was used ( P < 0.05. The mean hardness in photo-activated samples, in which there was no interposition of indirect materials, was significantly greater ( P < 0.01. Conclusions: It may be concluded that the interposition of the restorative material decreased the micro hardness in the deeper cement layer. Such decrease, however, was lower when the ceramic was interposed and the cement light-cured with LED.

  6. Which factors most influence referral for restorative dental treatment under sedation and general anaesthesia in children with complex disabilities: caries severity, child functioning, or dental service organisation?

    Science.gov (United States)

    Norderyd, Johanna; Faulks, Denise; Molina, Gustavo; Granlund, Mats; Klingberg, Gunilla

    2018-01-01

    The UN Convention on the Rights of the Child gives all children right to the highest standard of services for treatment and rehabilitation. For children with disabilities, sedation and general anaesthesia (GA) are often indicated for dental treatment; however, accessibility to this varies. The International Classification of Functioning, Disability and Health - Child and Youth version (ICF-CY) enables a biopsychosocial description of children undergoing dental treatment. To investigate conscious sedation and GA in children with complex disabilities and manifest caries and analyse how caries, child functioning, and dental service organisation relate to dental GA (DGA), comparing Argentina, France, and Sweden using the ICF-CY. Quantitative, cross-sectional; data collected through structured interviews, observation, and dental records. Sedation and DGA were common. Children with limitations in interpersonal interactions and relationships were more likely to have had DGA (OR: 5.3, P = 0.015). Level of caries experience was strongly correlated with experience of DGA. There were significant differences between countries regarding caries prevalence, sedation, DGA, and functional and environmental factors. Although caries experience and child functioning are important, dental health service organisation had the most impact on the incidence of DGA, and for the use of conscious sedation, for children with complex disabilities. © 2017 BSPD, IAPD and John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Milestones of dental history

    OpenAIRE

    Rajesh Mahant; S Vineet Agrawal; Sonali Kapoor; Isha Agrawal

    2017-01-01

    Since ages, human beings suffer from the dental problems. With the journey as time elapsed the person treating the teeth changed (i.e., from barbers and monks to present dentists), equipment changed (i.e., from bow drills to airotor and laser handpieces), materials changed (i.e., from ground mastic alum/honey to tooth colored composite and ceramics). There has been drastic change in treatment planning from extraction to the conservation of teeth and from manual restoration to computerized res...

  8. Students' perceptions of materials and techniques used at European dental schools in the education of fixed prosthodontics

    NARCIS (Netherlands)

    Brand, H.S.; Kamell, H.; Kharbanda, A.; Dozic, A.

    2013-01-01

    The aim of this study was to explore the materials and procedures used by students in dental schools across Europe for teaching fixed prosthodontics. An online questionnaire, containing twenty-eight dichotomous, multiple-choice, and Likert scale rating questions, was sent to students in forty dental

  9. A review of nanostructured surfaces and materials for dental implants: surface coating, patterning and functionalization for improved performance.

    Science.gov (United States)

    Rasouli, Rahimeh; Barhoum, Ahmed; Uludag, Hasan

    2018-05-10

    The emerging field of nanostructured implants has enormous scope in the areas of medical science and dental implants. Surface nanofeatures provide significant potential solutions to medical problems by the introduction of better biomaterials, improved implant design, and surface engineering techniques such as coating, patterning, functionalization and molecular grafting at the nanoscale. This review is of an interdisciplinary nature, addressing the history and development of dental implants and the emerging area of nanotechnology in dental implants. After a brief introduction to nanotechnology in dental implants and the main classes of dental implants, an overview of different types of nanomaterials (i.e. metals, metal oxides, ceramics, polymers and hydrides) used in dental implant together with their unique properties, the influence of elemental compositions, and surface morphologies and possible applications are presented from a chemical point of view. In the core of this review, the dental implant materials, physical and chemical fabrication techniques and the role of nanotechnology in achieving ideal dental implants have been discussed. Finally, the critical parameters in dental implant design and available data on the current dental implant surfaces that use nanotopography in clinical dentistry have been discussed.

  10. Success and Survival Rates of Dental Implants Restored at an Undergraduate Dental Clinic: A 13-Year Retrospective Study with a Mean Follow-up of 5.8 Years.

    Science.gov (United States)

    Daneshvar, Shahrzad S; Matthews, Debora C; Michuad, Pierre-Luc; Ghiabi, Edmond

    2016-01-01

    The purpose of this study was to evaluate the clinical, radiographic, and patient-based outcomes of dental implants placed at an undergraduate student dental clinic. A retrospective study was performed to determine the success and survival rates of dental implants placed at the undergraduate dental clinic at Dalhousie University between January 1999 and January 2012. Only patients with a minimum of 1-year follow-up were included. Clinical and radiographic assessments determined implant success and survival rates. Questionnaires recorded patients' satisfaction with esthetics, comfort, and ease of hygiene. Of the 352 patients (n = 591 implants) who received implants over 13 years, 165 patients completed the clinical and radiographic examinations. By the end of the study period, demographic information and implant characteristics were collected for 111 (n = 217 implants; 47.5% in the maxilla, 52.6% in the mandible) of these patients. Of those assessed clinically, 36.4% were males and 63.6% females, with a mean age of 56.1 ± 14.15 years (range, 17 to 86 years) at the time of implant placement. The mean follow-up period was 5.8 years (range, 1 to 13 years). The overall implant success and survival rates were 88.0% and 97.2%, respectively. No observable bone loss was evident in 88.0% of the surviving implants. There were no implant fractures. Most patients (91.2%) were very satisfied with the implant restoration appearance, 88.0% were very comfortable with the implant, 92.6% were very satisfied with their ability to chew, and 84.8% reported easy hygiene maintenance at the implant sites. Implant success and survival in an undergraduate student clinic were comparable to those reported in the literature. It seems that inexperienced students were able to provide restorations that were very satisfying to the patients.

  11. Chemical Differentiation of Osseous, Dental, and Non-skeletal Materials in Forensic Anthropology using Elemental Analysis.

    Science.gov (United States)

    Zimmerman, Heather A; Meizel-Lambert, Cayli J; Schultz, John J; Sigman, Michael E

    2015-03-01

    Forensic anthropologists are generally able to identify skeletal materials (bone and tooth) using gross anatomical features; however, highly fragmented or taphonomically altered materials may be problematic to identify. Several chemical analysis techniques have been shown to be reliable laboratory methods that can be used to determine if questionable fragments are osseous, dental, or non-skeletal in nature. The purpose of this review is to provide a detailed background of chemical analysis techniques focusing on elemental compositions that have been assessed for use in differentiating osseous, dental, and non-skeletal materials. More recently, chemical analysis studies have also focused on using the elemental composition of osseous/dental materials to evaluate species and provide individual discrimination, but have generally been successful only in small, closed groups, limiting their use forensically. Despite significant advances incorporating a variety of instruments, including handheld devices, further research is necessary to address issues in standardization, error rates, and sample size/diversity. Copyright © 2014 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

  12. 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.

  13. Central Anticholinergic Syndrome due to Hypoxia-Induced Bradycardia in a Child with Difficult Intubation Undergoing Complete Dental Restoration: A Case Report.

    Directory of Open Access Journals (Sweden)

    Mohamad Gharavifard

    2014-10-01

    Full Text Available Central anticholinergic syndrome (CAS following general anesthesia (GA is a well known syndrome in children and adults. Many cases of CAS have been previously reported in the literature. However, there are only two reports of post resuscitation CAS after administration of small doses of atropine. Hereby, we report a case of CAS in a child undergoing complete dental restoration under GA after receiving a small dose of atropine to reverse hypoxia induced bradycardia. Intraoperative events such as hypoxia or cardiac arrest may play a role as triggers for CAS. However, we cannot establish a causal relationship between the occurrence of CAS and such critical events.

  14. Central Anticholinergic Syndrome due to Hypoxia-Induced Bradycardia in a Child with Difficult Intubation Undergoing Complete Dental Restoration: A Case Report.

    Science.gov (United States)

    Gharavifard, Mohamad; Razavi, Majid; Ghandehari Motlagh, Mehdi; Ziyaeifard, Mohsen

    2014-09-01

    Central anticholinergic syndrome (CAS) following general anesthesia (GA) is a well known syndrome in children and adults. Many cases of CAS have been previously reported in the literature. However, there are only two reports of post resuscitation CAS after administration of small doses of atropine. Hereby, we report a case of CAS in a child undergoing complete dental restoration under GA after receiving a small dose of atropine to reverse hypoxia induced bradycardia. Intraoperative events such as hypoxia or cardiac arrest may play a role as triggers for CAS. However, we cannot establish a causal relationship between the occurrence of CAS and such critical events.

  15. The effect of different drinks on the color stability of different restorative materials after one month.

    Science.gov (United States)

    Tekçe, Neslihan; Tuncer, Safa; Demirci, Mustafa; Serim, Merve Efe; Baydemir, Canan

    2015-11-01

    The aim of this study was to evaluate the effect of three different drinks on the color parameters of four different restorative materials. Three different composites (Filtek Ultimate Universal Restorative, Filtek Ultimate Flowable, and Filtek Silorane, 3M ESPE) and a polyacid-modified composite resin material (Dyract XP, Dentsply DeTrey GmbH) were evaluated. Eighty-four disc-shaped specimens of 8 mm in diameter and 2 mm in thickness were prepared (n = 21 each). Color coordinates (L*a*b*, ΔL*, Δa*, Δb*, and ΔE*) were measured using a VİTA Easyshade Compact (VİTA Zahnfabrik) after 24 hr of storage (baseline) and after 30 day of storage in three different beverages of black tea, Coca cola, or water (control) (n = 7). In each beverage, the specimens were stored three times a day, one hr each, for 30 day. The color changes (ΔE) were calculated and were analyzed by Kruskal-Wallis and Dunn multiple comparison test. The color difference (ΔE*) of the resin materials ranged between 1.31 and 15.28 after 30 day of immersion in the staining solutions. Dyract XP in Coca cola (15.28 ± 2.61) and black tea (12.22 ± 2.73) showed the highest mean ΔE* value after 30 day, followed by Filtek Ultimate Universal Restorative (5.99 ± 1.25) and Filtek Ultimate Flowable (4.71 ± 1.40) in black tea (p < 0.05). The compomers displayed unacceptable color changes at the end of 30 day in all beverages. Among resin composites, the silorane based composite exhibited relatively good color stability than the others. Filtek Ultimate Universal Restorative and Filtek Flowable showed similar color changes in all beverages.

  16. Evaluation of the surface structure of composite restorations in light of own pilot research

    Directory of Open Access Journals (Sweden)

    Chalas Renata

    2016-09-01

    Full Text Available Research on the dental restorative materials employed in remedying dental cavities has been conducted on many levels and areas, both with application of clinical and laboratory methods. One of the elements that determines whether the restoration may be degraded is the condition of its surface. The aim of the study was to assess the texture surface of composite restorations using a non-contact method of teeth models scanning. In this work, ten medium size cavities on the occlusal surfaces of molars in adult patients were prepared and restored with resin composite. Before undertaking the procedure and after the finishing and polishing of the restorations, impressions were taken and sent into the laboratory so as to prepare plaster casts. Every cast was then scanned utilizing the non-contact 3D surface measurement instrument so as to assess the texture surface of the restoration. The resulting three dimensional analyses of post-restoration models showed the correct marginal adaptation of resin composite dental material to the hard tooth structures and its smooth filling occlusal surface. Additional comparison of scans done before and after restoring the cavities allowed the calculating of differences in volume, mean and maximum heights. The applied method of analysis is thought to be helpful in the detailed evaluation of restoration dental material texture. Moreover, the enabled possibility of continuous observation is expedient for assessing the usefulness of the method in standard dental practice.

  17. Evaluation of Candida albicans biofilm formation on various dental ...

    African Journals Online (AJOL)

    Evaluation of Candida albicans biofilm formation on various dental restorative material surfaces. ... Nigerian Journal of Clinical Practice ... was significantly lower on the resin-modified glass ionomer and glass-ionomer cement samples. ... Conclusion: This finding emphasizes the use of glass ionomer restorative cements and ...

  18. 75 FR 16511 - Pentron Clinical Technologies, a Wholly-Owned Subsidiary of Kerr Dental/Sybron Dental...

    Science.gov (United States)

    2010-04-01

    ... produce dental materials such as dental prosthetics, dental composites, dental impressions, dental... materials such as dental prosthetics, dental composites, dental impressions, dental adhesives, and other... Technologies, a Wholly-Owned Subsidiary of Kerr Dental/Sybron Dental Specialities, Formally Known as Customedix...

  19. Effect of fluoride addition on the properties of dental alginate impression materials.

    Science.gov (United States)

    Lee, Yong-Keun; Lim, Bum-Soon; Kim, Cheol-We

    2004-03-01

    Fluoride-containing dental alginate impression materials can exert a considerable reduction in enamel solubility. The objective was to evaluate the effects of fluoride addition in the alginate impression materials on the properties and subsequent release of fluoride. Four experimental alginate impression materials were studied. Materials were mixed with distilled water (control) or 100-ppm fluoride solution. One or two percent NaF, or 1% SnF2 was added to the materials, which were mixed with distilled water. Fluoride release, flexibility, recovery from deformation, setting time, compressive strength and elastic modulus were determined in accordance with the ISO 1563 and ANSI/ADA Spec. 18. Fluoride release increased after addition of fluoride, and the released amount was 0.762-14.761 ppm. Addition of NaF or SnF2 resulted in higher fluoride release than the control group (p alginate impression material may result in effective release of fluoride without deteriorating the properties of material itself.

  20. Eroded dentin does not jeopardize the bond strength of adhesive restorative materials

    Directory of Open Access Journals (Sweden)

    Janaina Barros Cruz

    2012-08-01

    Full Text Available This in vitro study evaluated the bond strength of adhesive restorative materials to sound and eroded dentin. Thirty-six bovine incisors were embedded in acrylic resin and ground to obtain flat buccal dentin surfaces. Specimens were randomly allocated in 2 groups: sound dentin (immersion in artificial saliva and eroded dentin (pH cycling model - 3× / cola drink for 7 days. Specimens were then reassigned according to restorative material: glass ionomer cement (KetacTM Molar Easy Mix, resin-modified glass ionomer cement (VitremerTM or adhesive system with resin composite (Adper Single Bond 2 + Filtek Z250. Polyethylene tubes with an internal diameter of 0.76 mm were placed over the dentin and filled with the material. The microshear bond test was performed after 24 h of water storage at 37ºC. The failure mode was evaluated using a stereomicroscope (400×. Bond strength data were analyzed with two-way ANOVA and Tukey's post hoc tests (α = 0.05. Eroded dentin showed bond strength values similar to those for sound dentin for all materials. The adhesive system showed the highest bond strength values, regardless of the substrate (p < 0.0001. For all groups, the adhesive/mixed failure prevailed. In conclusion, adhesive materials may be used in eroded dentin without jeopardizing the bonding quality. It is preferable to use an etch-and-rinse adhesive system because it shows the highest bond strength values compared with the glass ionomer cements tested.

  1. Does 6 Hours of Contact With Alginate Impression Material Affect Dental Cast Properties?

    Science.gov (United States)

    Ibrahim, Amna Adam; Alhajj, Mohammed Nasser; Khalifa, Nadia; Gilada, Magdi Wadie

    2017-06-01

    Alginate impression (irreversible hydrocolloid) material is commonly used in dental practice because it is easy to mix, low in cost, and well tolerated by patients. The material is not dimensionally stable, however; thus, it is necessary to pour the impression immediately after the molding is accomplished, or within 60 minutes if the impression is kept in 100% humidity. Excessive contact of the alginate impression with the cast model over time may affect the model's properties. In this study, the authors tested the effect of contact time between an alginate impression and type III dental stone on cast model properties. Sixty-seven cast models were obtained from a stainless steel cylinder by using irreversible hydrocolloid impression material and type III dental stone. Thirty-seven cast models were separated from the impression after 1 hour (control group) and 30 cast models were separated after 6 hours (study group). The samples were evaluated under light microscope for surface details and measured by digital caliper for dimensional stability. An indentation on the cast was made and the depth of the indentation was then measured with a digital caliper to measure hardness. The dimensional stability of the cast models was not affected when contact time was increased from 1 hour to 6 hours (P = .507). Surface details did not deteriorate when contact time was increased, as all of the samples could reproduce all details after the 1-hour and 6-hour interval periods. However, hardness was greater after 1 hour of contact time (P = .001) than after 6 hours of contact time. In conclusion, contact between alginate impression material and type III dental stone up to 6 hours did not affect the dimensional stability and richness of the surface; hardness, though, was significantly affected.

  2. A study on the radiopacity of cavity lining materials for posterior composite resin restoration

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Joo Hoon [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Chosun University, Kwangju (Korea, Republic of); Choi, Eui Hwan [Dept. of Conservative Dentistry, College of Dentistry, Chosun University, Kwangju (Korea, Republic of)

    2000-12-15

    The aim of this study was to determine the relative radiopacities of cavity lining materials (Resin-modified Glass Ionomer cement, Compomer and Flowable resin) for posterior composite resin restoration. Resin-modified glass ionomer cement (Fuji II LC, Vitrebond (TM)), Compomers (Dyract , Compoglass, F2000, Dyract(R) flow Compoglass Flow) and Flowable resins (Tetric (R) flow, Aeliteflo (TM) Revolution (TM)) were used. Five specimens of 5 mm in diameter and 2 mm thick were fabricated with each material. Human molars were horizontally sectioned 2 mm thick to include both enamel and dentin. The radiopacities of enamel, dentin, cavity lining materials, aluminum step wedge were obtained from conventional radiograph and NIH image program. All the tested lining materials showed levels of radiopacity the same as or greater than that of dentin. All compomer tested (Dyract (R), Compoglass, F2000, Dyract (R) flow, Compoglass Flow) and Vitrebond (TM), Tetric (R) flow were more radiopaque than enamel. The radiopacities of Fuji II LC and Revolution (TM) were between enamel and dentin and resin-modified glass ionomer cement, Compomer and Tetric (R) flow were greater than those of Revolution (TM), Aeliteflo (TM) or dentin. The level of radiopacity of the tested materials was variable; those with low radiopacity should be avoided in class II restorations, where a clear determination of recurrent caries by the examining clinician could be compromised. Clinician should be able to distinguish these cavity lining materials radiographically from recurrent decay, voids, gaps, or other defects that lead to clinical failure. Utilization of materials ranked more radiopaque than enamel would enable clinicians to distinguish the lining material from tooth structure.

  3. A study on the radiopacity of cavity lining materials for posterior composite resin restoration

    International Nuclear Information System (INIS)

    Moon, Joo Hoon; Choi, Eui Hwan

    2000-01-01

    The aim of this study was to determine the relative radiopacities of cavity lining materials (Resin-modified Glass Ionomer cement, Compomer and Flowable resin) for posterior composite resin restoration. Resin-modified glass ionomer cement (Fuji II LC, Vitrebond (TM)), Compomers (Dyract , Compoglass, F2000, Dyract(R) flow Compoglass Flow) and Flowable resins (Tetric (R) flow, Aeliteflo (TM) Revolution (TM)) were used. Five specimens of 5 mm in diameter and 2 mm thick were fabricated with each material. Human molars were horizontally sectioned 2 mm thick to include both enamel and dentin. The radiopacities of enamel, dentin, cavity lining materials, aluminum step wedge were obtained from conventional radiograph and NIH image program. All the tested lining materials showed levels of radiopacity the same as or greater than that of dentin. All compomer tested (Dyract (R), Compoglass, F2000, Dyract (R) flow, Compoglass Flow) and Vitrebond (TM), Tetric (R) flow were more radiopaque than enamel. The radiopacities of Fuji II LC and Revolution (TM) were between enamel and dentin and resin-modified glass ionomer cement, Compomer and Tetric (R) flow were greater than those of Revolution (TM), Aeliteflo (TM) or dentin. The level of radiopacity of the tested materials was variable; those with low radiopacity should be avoided in class II restorations, where a clear determination of recurrent caries by the examining clinician could be compromised. Clinician should be able to distinguish these cavity lining materials radiographically from recurrent decay, voids, gaps, or other defects that lead to clinical failure. Utilization of materials ranked more radiopaque than enamel would enable clinicians to distinguish the lining material from tooth structure.

  4. The effects of acid erosion and remineralization on enamel and three different dental materials: FT-Raman spectroscopy and scanning electron microscopy analysis.

    Science.gov (United States)

    Soares, Luís Eduardo Silva; Soares, Ana Lúcia Silva; De Oliveira, Rodrigo; Nahórny, Sidnei

    2016-07-01

    FT-Raman spectroscopy and scanning electron microscopy (SEM) were employed to test the hypothesis that the beverage consumption or mouthwash utilization would change the chemistry of dental materials and enamel inorganic content. Bovine enamel samples (n = 36) each received two cavity preparations (n = 72), each pair filled with one of three dental materials (R: nanofilled composite resin, GIC: glass-ionomer cement, RMGIC: resin-modified GIC). Furthermore, they were treated with three different solutions (S: artificial saliva, E: erosion/Pepsi Twist or EM: erosion + mouthwash/Colgate Plax). Reduction of carbonate content of enamel was greater in RE than RS (P erosion. Material degradation was greater after E and EM than S. GIC and RMGIC materials had a positive effect against acid erosion in the adjacent enamel after remineralization with mouthwash. The beverage and mouthwash utilization would change R and GIC chemical properties. A professional should periodically monitor the glass-ionomer and resin restorations, as they degrade over time under erosive challenges and mouthwash utilization. Microsc. Res. Tech., 2016. © 2016 Wiley Periodicals, Inc. Microsc. Res. Tech. 79:646-656, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  5. Adhesive luting of all-ceramic restorations--the impact of cementation variables and short-term water storage on the strength of a feldspathic dental ceramic.

    LENUS (Irish Health Repository)

    Addison, Owen

    2008-08-01

    To investigate the impact of resin cement luting variables and short-term water storage on the strength of an adhesively luted all-ceramic restorative material. An understanding of the strengthening mechanisms will result in optimisation of operative techniques and materials selection criteria.

  6. The potential of novel native plant materials for the restoration of novel ecosystems

    Directory of Open Access Journals (Sweden)

    T.A. Jones

    2015-05-01

    Full Text Available Abstract Extensive ecological change has been sustained by many dryland ecosystems throughout the world, resulting in conversion to so-called novel ecosystems. It is within such ecological contexts that native plant materials destined for ecological applications must be able to function. In the Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis [Beetle & A.M. Young] S.L. Welsh ecosystems of the Intermountain West, for example, novel ecosystem structure and functioning are pervasive. Invasive species, particularly annual grasses, fuel repeated wildfires that drive previously stable ecosystem states across thresholds to less desirable states that are highly recalcitrant to restoration efforts. Structural changes include reductions of native flora, damage to biological soil crusts, and alterations to soil microbiota. Functional changes include altered hydrologic and nutrient cycling, leading to permanent losses of soil organic matter and nitrogen that favor the invaders. We argue that there is an important place in restoration for plant materials that are novel and/or non-local that have been developed to be more effective in the novel ecosystems for which they are intended, thus qualifying them as “ecologically appropriate.” Such plant materials may be considered as an alternative to natural/local “genetically appropriate” plant materials, which are sometimes deemed best adapted due to vetting by historical evolutionary processes.

  7. Influence of ceramic thickness and ceramic materials on fracture resistance of posterior partial coverage restorations.

    Science.gov (United States)

    Bakeman, E M; Rego, N; Chaiyabutr, Y; Kois, J C

    2015-01-01

    This study evaluated the influence of ceramic thickness and ceramic materials on fracture resistance of posterior partial coverage ceramic restorations. Forty extracted molars were allocated into four groups (n=10) to test for two variables: 1) the thickness of ceramic (1 mm or 2 mm) and 2) the ceramic materials (a lithium disilicate glass-ceramic [IPS e.max] or leucite-reinforced glass ceramic [IPS Empress]). All ceramic restorations were luted with resin cement (Variolink II) on the prepared teeth. These luted specimens were loaded to failure in a universal testing machine, in the compression mode, with a crosshead speed of 1.0 mm/min. The data were analyzed using two-way analysis of variance and the Tukey Honestly Significantly Different multiple comparison test (α =0.05). The fracture resistance revealed a significant effect for materials (pceramic was not significant (p=0.074), and the interaction between the thickness of ceramic and the materials was not significant (p=0.406). Mean (standard deviation) fracture resistance values were as follows: a 2-mm thickness of a lithium disilicate bonded to tooth structure (2505 [401] N) revealed a significantly higher fracture resistance than did a 1-mm thickness of leucite-reinforced (1569 [452] N) and a 2-mm thickness of leucite-reinforced ceramic bonded to tooth structure (1716 [436] N) (pceramic at 1-mm thickness (2105 [567] N) and at 2-mm thickness. Using a lithium disilicate glass ceramic for partial coverage restoration significantly improved fracture resistance compared to using a leucite-reinforced glass ceramic. The thickness of ceramic had no significant effect on fracture resistance when the ceramics were bonded to the underlying tooth structure.

  8. Synthesis, characterization and antibacterial activity of copper, nickel and bimetallic Cu–Ni nanoparticles for potential use in dental materials

    Directory of Open Access Journals (Sweden)

    Liliana Argueta-Figueroa

    2014-08-01

    Full Text Available The antibacterial effect is a desirable property in dental materials. Development of simple methods for the preparation of nanosized metal particles has attracted significant attention because of their future applications due to unusual size-dependent antibacterial properties. Copper (Cu, Nickel (Ni and bimetallic Cu–Ni nanoparticles were prepared by a simple chemical method and their antibacterial activity was tested against the widely used standard human pathogens Staphylococcus aureus (gram-negative and Escherichia coli (gram-positive. Additionally, these nanoparticles were tested against the dental pathogen Streptococcus mutans. Our results are promising for potential use in dental materials science.

  9. A novel laser-based method for controlled crystallization in dental prosthesis materials

    Science.gov (United States)

    Cam, Peter; Neuenschwander, Beat; Schwaller, Patrick; Köhli, Benjamin; Lüscher, Beat; Senn, Florian; Kounga, Alain; Appert, Christoph

    2015-02-01

    Glass-ceramic materials are increasingly becoming the material of choice in the field of dental prosthetics, as they can feature both high strength and very good aesthetics. It is believed that their color, microstructure and mechanical properties can be tuned such as to achieve an optimal lifelike performance. In order to reach that ultimate perfection a controlled arrangement of amorphous and crystalline phases in the material is required. A phase transformation from amorphous to crystalline is achieved by a heat treatment at defined temperature levels. The traditional approach is to perform the heat treatment in a furnace. This, however, only allows a homogeneous degree of crystallization over the whole volume of the parent glass material. Here a novel approach using a local heat treatment by laser irradiation is presented. To investigate the potential of this approach the crystallization process of SiO2-Li2O-Al2O3-based glass has been studied with laser systems (pulsed and continuous wave) operating at different wavelengths. Our results show the feasibility of gradual and partial crystallization of the base material using continuous laser irradiation. A dental prosthesis machined from an amorphous glassy state can be effectively treated with laser irradiation and crystallized within a confined region of a few millimeters starting from the body surface. Very good aesthetics have been achieved. Preliminary investigation with pulsed nanosecond lasers of a few hundreds nanoseconds pulse width has enabled more refinement of crystallization and possibility to place start of phase change within the material bulk.

  10. Effect of different composite core materials on fracture resistance of endodontically treated teeth restored with FRC posts

    OpenAIRE

    PANITIWAT, Prapaporn; SALIMEE, Prarom

    2017-01-01

    Abstract Objective This study evaluated the fracture resistance of endodontically treated teeth restored with fiber reinforced composite posts, using three resin composite core build-up materials, (Clearfil Photo Core (CPC), MultiCore Flow (MCF), and LuxaCore Z-Dual (LCZ)), and a nanohybrid composite, (Tetric N-Ceram (TNC)). Material and Methods Forty endodontically treated lower first premolars were restored with quartz fiber posts (D.T. Light-Post) cemented with resin cement (Panavia F2...

  11. Methods dentists use to diagnose primary caries lesions prior to restorative treatment: findings from The Dental PBRN

    DEFF Research Database (Denmark)

    Rindal, D Brad; Gordan, Valeria V; Litaker, Mark S

    2010-01-01

    To (1) quantify the diagnostic techniques used by Dental Practice-Based Research Network (DPBRN) dentists before they decide to treat primary caries lesions surgically and (2) examine whether certain dentist, practice, and patient characteristics are associated with their use.......To (1) quantify the diagnostic techniques used by Dental Practice-Based Research Network (DPBRN) dentists before they decide to treat primary caries lesions surgically and (2) examine whether certain dentist, practice, and patient characteristics are associated with their use....

  12. Longterm survival and reason for failure of anterior composite restoration

    Directory of Open Access Journals (Sweden)

    Nina Djustiana

    2016-06-01

    Full Text Available Composites resin restorations have been used for repairing and restoring anterior teeth for decades due to the growing needs for a cost- effective aesthetic restoration and the advancement in dental material and polymer technology. Failure of composite restorations cannot be neglected, due to multiple factors, i.e. failure to diagnose the gingival tissue, inadequate tissue management, quality of remaining tooth structure, and inadequate preparation. The aim of this review is to improve clinical performances of direct composite as permanent restorations. Long lasting aesthetic composite restorations required proper mouth preparations ,which  includes supporting and dental hard tissue preparations, tooth preparation, proper isolation, bonding procedures, light cure unit, and the resin composite itself.

  13. Provision of Atraumatic Restorative Treatment (ART) restorations to Chinese pre-school children--a 30-month evaluation.

    Science.gov (United States)

    Lo, E C; Holmgren, C J

    2001-01-01

    The objectives of this study were: to provide restorations using the ART approach to pre-school children in Southern China in a kindergarten environment, using a high-strength glass-ionomer restorative material; to assess the acceptability of this approach and to evaluate on a longitudinal basis the restorations placed. A total of 170 ART restorations were placed in 95 children, aged 5.1 +/- 0.7 years, by seven final-year dental students using standard ART procedures and hand instruments. The restorations were evaluated every six months thereafter by two calibrated independent examiners using explorers and mouth-mirrors. 93% of the children reported that they did not feel pain during treatment and 86% were willing to receive ART restorations again. The cumulative 12- and 30-month survival rates of Class I restorations were 91% and 79%, respectively. The corresponding figures for Class V restorations were 79% and 70%, while those for Class II restorations were 75% and 51%. The failure rates of Class III and IV restorations were high with more than half of them scored as missing within the first year. The ART approach was shown to be acceptable to Chinese pre-school children for providing restorative dental care outside the traditional clinical setting. The success rates were high for Class I and V restorations in primary teeth, modest for Class II, and low for Class III and IV restorations.

  14. Translucency changes of direct esthetic restorative materials after curing, aging and treatment

    Directory of Open Access Journals (Sweden)

    Yong-Keun Lee

    2016-11-01

    Full Text Available The purpose of this article was to review the changes in translucency of direct esthetic restorative materials after curing, aging and treatment. As a criterion for the evaluation of clinical translucency changes, visual perceptibility threshold in translucency parameter difference (ΔTP of 2 was used. Translucency changes after curing were perceivable depending on experimental methods and products (largest ΔTP in resin composites = 15.9. Translucency changes after aging were reported as either relatively stable or showed perceivable changes by aging protocols (largest ΔTP in resin composites = -3.8. Translucency changes after curing, aging and treatment were perceivable in several products and experimental methods. Therefore, shade matching of direct esthetic materials should be performed considering these instabilities of translucency in direct esthetic materials.

  15. The effect of orthodontic bonding materials on dental plaque accumulation and composition in vitro.

    Science.gov (United States)

    Badawi, H; Evans, R D; Wilson, M; Ready, D; Noar, J H; Pratten, J

    2003-08-01

    The aim of this study was to investigate the accumulation and composition of microcosm dental plaque on different orthodontic bonding materials using an in vitro model. Microcosm plaques were grown on discs of a range of bonding materials in a constant depth film fermentor. The biofilms were derived from human saliva and supplied with artificial saliva as a source of nutrients. The number of viable bacteria in the biofilms was determined and the streptococci present were identified to species level. The results showed that there was no significant difference in bacterial accumulation between different bonding materials, however, biofilms grown on materials which were fluoride releasing, did not contain Streptococcus mutans. This in vitro study has shown that the use of fluoride-releasing bonding materials may support the growth of supragingival plaque, which does not contain S. mutans.

  16. Evaluation of a new nano-filled restorative material for bonding orthodontic brackets.

    Science.gov (United States)

    Bishara, Samir E; Ajlouni, Raed; Soliman, Manal M; Oonsombat, Charuphan; Laffoon, John F; Warren, John

    2007-01-01

    To compare the shear bond strength of a nano-hybrid restorative material, Grandio (Voco, Cuxhaven, Germany), to that of a traditional adhesive material (Transbond XT; 3M Unitek, Monrovia, CA, USA) when bonding orthodontic brackets. Forty teeth were randomly divided into 2 groups: 20 teeth were bonded with the Transbond adhesive system and the other 20 teeth with the Grandio restorative system, following manufacturer's instructions. Student t test was used to compare the shear bond strength of the 2 systems. Significance was predetermined at P 5 .05. The t test comparisons (t = 0.55) of the shear bond strength between the 2 adhesives indicated the absence of a significant (P = .585) difference. The mean shear bond strength for Grandio was 4.1 +/- 2.6 MPa and that for Transbond XT was 4.6 +/- 3.2 MPa. During debonding, 3 of 20 brackets (15%) bonded with Grandio failed without registering any force on the Zwick recording. None of the brackets bonded with Transbond XT had a similar failure mode. The newly introduced nano-filled composite materials can potentially be used to bond orthodontic brackets to teeth if its consistency can be more flowable to readily adhere to the bracket base.

  17. New nanomaterials for applications in conservation and restoration of stony materials: A review

    International Nuclear Information System (INIS)

    Sierra-Fernandez, A.; Gomez-Villalba, L.S.; Rabanal, M.E.; Fort, R.

    2017-01-01

    In recent times, nanomaterials have been applied in the construction and maintenance of the world's cultural heritage with the aim of improving the consolidation and protection treatments of damaged stone. These nanomaterials include important advantages that could solve many problems found in the traditional interventions. The present paper aims to carry out a review of the state of art on the application of nanotechnology to the conservation and restoration of the stony cultural heritage. We highlight the different types of nanoparticles currently used to produce conservation treatments with enhanced material properties and novel functionalities.

  18. Process Development of Porcelain Ceramic Material with Binder Jetting Process for Dental Applications

    Science.gov (United States)

    Miyanaji, Hadi; Zhang, Shanshan; Lassell, Austin; Zandinejad, Amirali; Yang, Li

    2016-03-01

    Custom ceramic structures possess significant potentials in many applications such as dentistry and aerospace where extreme environments are present. Specifically, highly customized geometries with adequate performance are needed for various dental prostheses applications. This paper demonstrates the development of process and post-process parameters for a dental porcelain ceramic material using binder jetting additive manufacturing (AM). Various process parameters such as binder amount, drying power level, drying time and powder spread speed were studied experimentally for their effect on geometrical and mechanical characteristics of green parts. In addition, the effects of sintering and printing parameters on the qualities of the densified ceramic structures were also investigated experimentally. The results provide insights into the process-property relationships for the binder jetting AM process, and some of the challenges of the process that need to be further characterized for the successful adoption of the binder jetting technology in high quality ceramic fabrications are discussed.

  19. Outcomes of implants and restorations placed in general dental practices: a retrospective study by the Practitioners Engaged in Applied Research and Learning (PEARL) Network.

    Science.gov (United States)

    Da Silva, John D; Kazimiroff, Julie; Papas, Athena; Curro, Frederick A; Thompson, Van P; Vena, Donald A; Wu, Hongyu; Collie, Damon; Craig, Ronald G

    2014-07-01

    restorations replaced or judged as needing to be replaced. The majority of P-Is and patients were satisfied with the esthetic outcomes for both the implant and restoration. These results suggest that implant survival and success rates in general dental practices may be lower than those reported in studies conducted in academic or specialty settings. The results of this study, generated in the private general practice setting, add to the evidence base to facilitate implant treatment planning.

  20. Using modified polyetheretherketone (PEEK) as an alternative material for endocrown restorations: A short-term clinical report.

    Science.gov (United States)

    Zoidis, Panagiotis; Bakiri, Eleonora; Polyzois, Gregory

    2017-03-01

    A modified polyetheretherketone (PEEK) framework material veneered with indirect light-polymerized composite resin was used as an alternative material for the fabrication of an endocrown restoration for an extensively damaged molar. The elastic modulus of the polyetheretherketone framework (4 GPa) veneered with indirect composite resin could dampen the occlusal forces protecting tooth structures better than ceramic materials. This is important in the restoration of extensively damaged molars with weak roots. Long-term clinical evidence is required before recommending the application as a substitute material. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  1. Edge chipping resistance and flexural strength of polymer infiltrated ceramic network and resin nanoceramic restorative materials.

    Science.gov (United States)

    Argyrou, Renos; Thompson, Geoffrey A; Cho, Seok-Hwan; Berzins, David W

    2016-09-01

    Two novel restorative materials, a polymer infiltrated ceramic network (PICN) and a resin nanoceramic (RNC), for computer-assisted design and computer-assisted manufacturing (CAD-CAM) applications have recently become commercially available. Little independent evidence regarding their mechanical properties exists to facilitate material selection. The purpose of this in vitro study was to measure the edge chipping resistance and flexural strength of the PICN and RNC materials and compare them with 2 commonly used feldspathic ceramic (FC) and leucite reinforced glass-ceramic (LRGC) CAD-CAM materials that share the same clinical indications. PICN, RNC, FC, and LRGC material specimens were obtained by sectioning commercially available CAD-CAM blocks. Edge chipping test specimens (n=20/material) were adhesively attached to a resin substrate before testing. Edge chips were produced using a 120-degree, sharp, conical diamond indenter mounted on a universal testing machine and positioned 0.1 to 0.7 mm horizontally from the specimen's edge. The chipping force was plotted against distance to the edge, and the data were fitted to linear and quadratic equations. One-way ANOVA determined intergroup differences (α=.05) in edge chipping toughness. Beam specimens (n=22/material) were tested for determining flexural strength using a 3-point bend test. Weibull statistics determined intergroup differences (α=.05). Flexural modulus and work of fracture were also calculated, and 1-way ANOVA determined intergroup differences (α=.05) RESULTS: Significant (Pmaterials for the 4 mechanical properties. Specifically, the material rankings were edge chipping toughness: RNC>LRGC=FC>PICN; flexural strength: RNC=LRGC>PICN>FC; flexural modulus: RNCLRGC=PICN>FC. The RNC material demonstrated superior performance for the mechanical properties tested compared with the other 3 materials. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All

  2. Referral for secondary restorative dental care in rural and urban areas of Scotland: findings from the Highlands Et Islands Teledentistry Project.

    Science.gov (United States)

    Nuttall, N M; Steed, M S; Donachie, M A

    2002-02-23

    To compare the reported level of use of secondary care services for restorative dental care in rural and urban areas of Scotland. Postal questionnaire survey Postal questionnaire sent to all dentists in the Highland region, the island regions in Scotland and Dumfries Et Galloway (n = 150) and an equal number were sampled from the remainder of Scotland stratified by health board area. Non-respondents were sent 2 reminders after which 62% of the sample had responded. Most dentists (85%) who practised in what they considered were urban areas of Scotland said they felt that they had good access to a secondary referral service. Whereas most of those who practised in what they considered were rural areas either said they had no access to such a service (26%) or that access was difficult (53%), only 3% of those in urban areas said they had no access to a secondary restorative consultative service compared with 14% of dentists practising in rural areas of mainland Scotland and 54% of those practising on Scottish islands. The survey suggests the people of the Scottish islands and some of the remoter parts of the Scottish mainland would be among those who might benefit from improvement in access to a restorative dentistry consultant service.

  3. Failure analysis of various monolithic posterior aesthetic dental crowns using finite element method

    Science.gov (United States)

    Porojan, Liliana; Topală, Florin

    2017-08-01

    The aim of the study was to assess the effect of material stiffness and load on the biomechanical performance of the monolithic full-coverage posterior aesthetic dental crowns using finite element analysis. Three restorative materials for monolithic dental crowns were selected for the study: zirconia; lithium disilicate glass-ceramic, and resin-based composite. Stresses were calculated in the crowns for all materials and in the teeth structures, under different load values. The experiments show that dental crowns made from all this new aesthetic materials processed by CAD/CAM technologies would be indicated as monolithic dental crowns for posterior areas.

  4. Shear Bond Strength of Three Orthodontic Bonding Systems on Enamel and Restorative Materials

    Directory of Open Access Journals (Sweden)

    Andreas Hellak

    2016-01-01

    Full Text Available Objective. The aim of this in vitro study was to determine the shear bond strength (SBS and adhesive remnant index (ARI score of two self-etching no-mix adhesives (iBond™ and Scotchbond™ on different prosthetic surfaces and enamel, in comparison with the commonly used total etch system Transbond XT™. Materials and Methods. A total of 270 surfaces (1 enamel and 8 restorative surfaces, n=30 were randomly divided into three adhesive groups. In group 1 (control brackets were bonded with Transbond XT primer. In the experimental groups iBond adhesive (group 2 and Scotchbond Universal adhesive (group 3 were used. The SBS was measured using a Zwicki 1120™ testing machine. The ARI and SBS were compared statistically using the Kruskal–Wallis test (P≤0.05. Results. Significant differences in SBS and ARI were found between the control group and experimental groups. Conclusions. Transbond XT showed the highest SBS on human enamel. Scotchbond Universal on average provides the best bonding on all other types of surface (metal, composite, and porcelain, with no need for additional primers. It might therefore be helpful for simplifying bonding in orthodontic procedures on restorative materials in patients. If metal brackets have to be bonded to a metal surface, the use of a dual-curing resin is recommended.

  5. Shear Bond Strength of Three Orthodontic Bonding Systems on Enamel and Restorative Materials.

    Science.gov (United States)

    Hellak, Andreas; Ebeling, Jennifer; Schauseil, Michael; Stein, Steffen; Roggendorf, Matthias; Korbmacher-Steiner, Heike

    2016-01-01

    Objective. The aim of this in vitro study was to determine the shear bond strength (SBS) and adhesive remnant index (ARI) score of two self-etching no-mix adhesives (iBond ™ and Scotchbond ™ ) on different prosthetic surfaces and enamel, in comparison with the commonly used total etch system Transbond XT ™ . Materials and Methods . A total of 270 surfaces (1 enamel and 8 restorative surfaces, n = 30) were randomly divided into three adhesive groups. In group 1 (control) brackets were bonded with Transbond XT primer. In the experimental groups iBond adhesive (group 2) and Scotchbond Universal adhesive (group 3) were used. The SBS was measured using a Zwicki 1120 ™ testing machine. The ARI and SBS were compared statistically using the Kruskal-Wallis test ( P ≤ 0.05). Results . Significant differences in SBS and ARI were found between the control group and experimental groups. Conclusions . Transbond XT showed the highest SBS on human enamel. Scotchbond Universal on average provides the best bonding on all other types of surface (metal, composite, and porcelain), with no need for additional primers. It might therefore be helpful for simplifying bonding in orthodontic procedures on restorative materials in patients. If metal brackets have to be bonded to a metal surface, the use of a dual-curing resin is recommended.

  6. Current Concepts in Restorative Implant Dentistry

    Institute of Scientific and Technical Information of China (English)

    Prof.Marchack

    2009-01-01

    Patients today are incteasingly aware of dental implants.and their expectations are for esthetically and functionally pleasingimplant restorations that mimic natural teeth.This presentation will give both the experienced and novice practitioner a better understand-ing of how restorative implant dentistry has evolved.Treatment planning and restorative options for single implants.multiple implants andfully edentulons arches will be discussed,and the use of modern materials and CADCAM technology in fabricating the most contemporaryfixed implant supported prostheses will be demonstrated.

  7. Evaluating the effect of antioxidant agents on shear bond strength of tooth-colored restorative materials after bleaching: A systematic review.

    Science.gov (United States)

    Feiz, Atiyeh; Mosleh, Hamid; Nazeri, Rahman

    2017-07-01

    The main objective of the present study was to make a systematic review of how antioxidant agents affect shear bond strength of tooth-colored restorative materials after bleaching. Electronic search was used to extract the related articles on the targeted key words such as "antioxidant", "dental bleaching" and "shear bond strength" (SBS) from MeSH, PubMed, Medline, and Cochrane electronic data bases. These articles were all published before 2016. Inclusion criteria were restricted to English journal articles concerning humans, clinical trials, cohorts and case-control studies. Therefore, systematic reviews, case reports, letters to editors, editorials and congress abstracts were excluded from the analysis. Most studies conducted on the issue have produced experimental data which are rather controversial, and there is no general agreement about the reported outcomes. As an illustration, most studies have not considered the relationship between the type of antioxidant materials and the shear bond strength. In point of fact, some researchers (e.g Kimyai et al.) have concluded that antioxidants like gel and solution leave similar effects on SBS. Alternatively, certain studies (e.g., Kunt et al.) have produced inconclusive data regarding the impact of one week postponement of the restorative process on SBS after the bleaching process. The results of the studies evaluating the role of various adhesive systems used after bleaching have demonstrated that regardless of the type of adhesive system used, applying antioxidants before restorative procedures can adversely affect the bleaching agents utilized for SBS. It has also been suggested that the type of the adhesive system used might be correlated with the magnitude of SBS. The results obtained from the systematic review of the articles under investigation reflected that the use of antioxidant agents, regardless of their type, form, concentration and duration of application, can improve SBS after bleaching. Copyright

  8. Posterior composite restoration update: focus on factors influencing form and function

    Science.gov (United States)

    Bohaty, Brenda S; Ye, Qiang; Misra, Anil; Sene, Fabio; Spencer, Paulette

    2013-01-01

    Restoring posterior teeth with resin-based composite materials continues to gain popularity among clinicians, and the demand for such aesthetic restorations is increasing. Indeed, the most common aesthetic alternative to dental amalgam is resin composite. Moderate to large posterior composite restorations, however, have higher failure rates, more recurrent caries, and increased frequency of replacement. Investigators across the globe are researching new materials and techniques that will improve the clinical performance, handling characteristics, and mechanical and physical properties of composite resin restorative materials. Despite such attention, large to moderate posterior composite restorations continue to have a clinical lifetime that is approximately one-half that of the dental amalgam. While there are numerous recommendations regarding preparation design, restoration placement, and polymerization technique, current research indicates that restoration longevity depends on several variables that may be difficult for the dentist to control. These variables include the patient’s caries risk, tooth position, patient habits, number of restored surfaces, the quality of the tooth–restoration bond, and the ability of the restorative material to produce a sealed tooth–restoration interface. Although clinicians tend to focus on tooth form when evaluating the success and failure of posterior composite restorations, the emphasis must remain on advancing our understanding of the clinical variables that impact the formation of a durable seal at the restoration–tooth interface. This paper presents an update of existing technology and underscores the mechanisms that negatively impact the durability of posterior composite restorations in permanent teeth. PMID:23750102

  9. Fatigue of dental ceramics.

    Science.gov (United States)

    Zhang, Yu; Sailer, Irena; Lawn, Brian R

    2013-12-01

    Clinical data on survival rates reveal that all-ceramic dental prostheses are susceptible to fracture from repetitive occlusal loading. The objective of this review is to examine the underlying mechanisms of fatigue in current and future dental ceramics. The nature of various fatigue modes is elucidated using fracture test data on ceramic layer specimens from the dental and biomechanics literature. Failure modes can change over a lifetime, depending on restoration geometry, loading conditions and material properties. Modes that operate in single-cycle loading may be dominated by alternative modes in multi-cycle loading. While post-mortem examination of failed prostheses can determine the sources of certain fractures, the evolution of these fractures en route to failure remains poorly understood. Whereas it is commonly held that loss of load-bearing capacity of dental ceramics in repetitive loading is attributable to chemically assisted 'slow crack growth' in the presence of water, we demonstrate the existence of more deleterious fatigue mechanisms, mechanical rather than chemical in nature. Neglecting to account for mechanical fatigue can lead to gross overestimates in predicted survival rates. Strategies for prolonging the clinical lifetimes of ceramic restorations are proposed based on a crack-containment philosophy. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Characteristics of pristine volcanic materials: Beneficial and harmful effects and their management for restoration of agroecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Anda, Markus, E-mail: markusandas@yahoo.com; Suparto; Sukarman

    2016-02-01

    Eruption of Sinabung volcano in Indonesia began again in 2010 after resting for 1200 years. The volcano is daily emitting ash and pyroclastic materials since September 2013 to the present, damaging agroecosystems and costing for management restoration. The objective of the study was to assess properties and impacts of pristine volcanic material depositions on soil properties and to provide management options for restoring the affected agroecosytem. Land satellite imagery was used for field studies to observe the distribution, thickness and properties of ashfall deposition. The pristine ashfall deposits and the underlying soils were sampled for mineralogical, soluble salt, chemical, physical and toxic compound analyses. Results showed that uneven distribution of rainfall at the time of violent eruption caused the areas receiving mud ashfall developed surface encrustation, which was not occur in areas receiving dry ashfall. Ashfall damaged the agroecosytem by burning vegetation, forming surface crusts, and creating soil acidity and toxicity. X-ray diffraction (XRD) and scanning electron microscope (SEM) analyses of encrustated layer indicated the presence of gypsum and jarosite minerals. Gypsum likely acted as a cementing agent in the formation of the encrustation layer with extremely low pH (2.9) and extremely high concentrations of Al, Ca and S. Encrustation is responsible for limited water infiltration and root penetration, while the extremely high concentration of Al is responsible for crop toxicity. Mud ashfall and dry ashfall deposits also greatly changed the underlying soil properties by decreasing soil pH and cation exchange capacity and by increasing exchangeable Ca, Al, and S availability. Despite damaging vegetation in the short-term, the volcanic ashfall enriched the soil in the longer term by adding nutrients like Ca, Mg, K, Na, P, Si and S. Suggested management practices to help restore the agroecosystem after volcanic eruptions include: (i) the

  11. Botulinum Toxin Type A as Preoperative Treatment for Immediately Loaded Dental Implants Placed in Fresh Extraction Sockets for Full-Arch Restoration of Patients With Bruxism.

    Science.gov (United States)

    Mijiritsky, Eitan; Mortellaro, Carmen; Rudberg, Omri; Fahn, Miri; Basegmez, Cansu; Levin, Liran

    2016-05-01

    The aim of the present report was to describe the use of Botulinum toxin type A as preoperative treatment for immediately loaded dental implants placed in fresh extraction sockets for full-arch restoration of patients with bruxism. Patients with bruxism who were scheduled to receive immediately loaded full-arch implant supported fixed restorations were included in this retrospective clinical report. To reduce the occlusal forces applied in patients with bruxism, Botulinum toxin type A was introduced prior to the implant placement procedure. Patients were followed and implant survival as well as peri-implant bone level was assessed in each periodic follow-up visit. Adverse effects were also recorded. A control group with no use of Botulinum toxin was evaluated as well. A total of 26 patients (13 test and 13 control), with bruxism, aged 59.15 ± 11.43 years on average were included in this retrospective report and received immediately loaded dental implants placed in fresh extraction sockets for full-arch restoration. The test group treatment preceded by Botulinum toxin type A injection. Maxillary arches were supported by 8 to 10 implants while the mandibular arch was supported by 6 implants. All surgeries went uneventfully and no adverse effects were observed. The average follow-up time was 32.5 ± 10.4 months (range, 18-51). In the test group, no implant failures were recorded. One patient presented with 1 to 2 mm bone loss around 4 of the implants; the other implants presented with stable bone level. In the control group 1 patient lost 2 implants and another demonstrated 2 mm bone loss around 3 of the implants. The preoperative use of Botulinum toxin in patients with bruxism undergoing full-arch rehabilitation using immediately loaded dental implants placed in fresh extraction sockets seems to be a technique that deserves attention. Further long-term, large-scale randomized clinical trials will help to determine the additional benefit of this suggested

  12. Analysis of explosion-induced releases of toxic materials at an environmental restoration project

    International Nuclear Information System (INIS)

    Bloom, S.G.; Moon, W.H. Jr.

    1993-01-01

    Prior to 1988, a variety of materials were buried on the US DOE Oak Ridge Reservation. Records of the disposal operations are incomplete and toxic materials may have been placed adjacent to potential explosives. One of the safety concerns in conducting an environmental restoration project at the burial sites, is the possibility of an explosion which could release toxic materials to the atmosphere. A safety analysis examined the consequences of such releases by first postulating an upper bound for the strength of an explosive. A correlation, developed by Steindler and Seefeldt of Argonne National Laboratory, was then used to estimate the amount and particle-size distribution of the material that could become airborne from the explosion. The estimated amount of airborne material was the source term in an atmospheric dispersion model which was used to calculate infinite-time, concentration-time integrals and 5-minute, time- weighted average concentrations at locations down-wind from the explosion. The dispersion model includes particle deposition as a function of particle-size distribution class. The concentration-time integrals and average concentrations were compared to published guidelines to assess the consequences of an accidental explosion

  13. Long-term evaluation of extensive restorations in permanent teeth

    DEFF Research Database (Denmark)

    Nieuwenhuysen, J.-P. van; D'hoore, W.D.; Carvalho, J.

    2003-01-01

    Biostatistics, cast crowns, complex restorations, composite resins, decision making, dental amalgam, metal ceramic crowns, multi-surfaced restorations, prosthodontics, restorative dentistry......Biostatistics, cast crowns, complex restorations, composite resins, decision making, dental amalgam, metal ceramic crowns, multi-surfaced restorations, prosthodontics, restorative dentistry...

  14. Surface deterioration of dental materials after simulated toothbrushing in relation to brushing time and load.

    Science.gov (United States)

    Heintze, S D; Forjanic, M; Ohmiti, K; Rousson, V

    2010-04-01

    (1) To evaluate the changes in surface roughness and gloss after simulated toothbrushing of 9 composite materials and 2 ceramic materials in relation to brushing time and load in vitro; (2) to assess the relationship between surface gloss and surface roughness. Eight flat specimens of composite materials (microfilled: Adoro, Filtek Supreme, Heliomolar; microhybrid: Four Seasons, Tetric EvoCeram; hybrid: Compoglass F, Targis, Tetric Ceram; macrohybrid: Grandio), two ceramic materials (IPS d.SIGN and IPS Empress polished) were fabricated according to the manufacturer's instructions and optimally polished with up to 4000 grit SiC. The specimens were subjected to a toothbrushing (TB) simulation device (Willytec) with rotating movements, toothpaste slurry and at three different loads (100g/250g/350g). At hourly intervals from 1h to 10h TB, mean surface roughness Ra was measured with an optical sensor and the surface gloss (Gl) with a glossmeter. Statistical analysis was performed for log-transformed Ra data applying two-way ANOVA to evaluate the interaction between load and material and load and brushing time. There was a significant interaction between material and load as well as between load and brushing time (pgloss was the parameter which discriminated best between the materials, followed by mean surface roughness Ra. There was a strong correlation between surface gloss and surface roughness for all the materials except the ceramics. The evaluation of the deterioration curves of individual specimens revealed a more or less synchronous course suspecting hinting specific external conditions and not showing the true variability in relation to the tested material. The surface roughness and gloss of dental materials changes with brushing time and load and thus results in different material rankings. Apart from Grandio, the hybrid composite resins were more prone to surface changes than microfilled composites. The deterioration potential of a composite material can be

  15. Cellular Responses in Human Dental Pulp Stem Cells Treated with Three Endodontic Materials

    Directory of Open Access Journals (Sweden)

    Alejandro Victoria-Escandell

    2017-01-01

    Full Text Available Human dental pulp stem cells (HDPSCs are of special relevance in future regenerative dental therapies. Characterizing cytotoxicity and genotoxicity produced by endodontic materials is required to evaluate the potential for regeneration of injured tissues in future strategies combining regenerative and root canal therapies. This study explores the cytotoxicity and genotoxicity mediated by oxidative stress of three endodontic materials that are widely used on HDPSCs: a mineral trioxide aggregate (MTA-Angelus white, an epoxy resin sealant (AH-Plus cement, and an MTA-based cement sealer (MTA-Fillapex. Cell viability and cell death rate were assessed by flow cytometry. Oxidative stress was measured by OxyBlot. Levels of antioxidant enzymes were evaluated by Western blot. Genotoxicity was studied by quantifying the expression levels of DNA damage sensors such as ATM and RAD53 genes and DNA damage repair sensors such as RAD51 and PARP-1. Results indicate that AH-Plus increased apoptosis, oxidative stress, and genotoxicity markers in HDPSCs. MTA-Fillapex was the most cytotoxic oxidative stress inductor and genotoxic material for HDPSCs at longer times in preincubated cell culture medium, and MTA-Angelus was less cytotoxic and genotoxic than AH-Plus and MTA-Fillapex at all times assayed.

  16. Accuracy of a new elastomeric impression material for complete-arch dental implant impressions.

    Science.gov (United States)

    Baig, Mirza R; Buzayan, Muaiyed M; Yunus, Norsiah

    2018-05-01

    The aim of the present study was to assess the accuracy of multi-unit dental implant casts obtained from two elastomeric impression materials, vinyl polyether silicone (VPES) and polyether (PE), and to test the effect of splinting of impression copings on the accuracy of implant casts. Forty direct impressions of a mandibular reference model fitted with six dental implants and multibase abutments were made using VPES and PE, and implant casts were poured (N = 20). The VPES and PE groups were split into four subgroups of five each, based on splinting type: (a) no splinting; (b) bite registration polyether; (c) bite registration addition silicone; and (d) autopolymerizing acrylic resin. The accuracy of implant-abutment replica positions was calculated on the experimental casts, in terms of interimplant distances in the x, y, and z-axes, using a coordinate measuring machine; values were compared with those measured on the reference model. Data were analyzed using non-parametrical Kruskal-Wallis and Mann-Whitney tests at α = .05. The differences between the two impression materials, VPES and PE, regardless of splinting type, were not statistically significant (P>.05). Non-splinting and splinting groups were also not significantly different for both PE and VPES (P>.05). The accuracy of VPES impression material seemed comparable with PE for multi-implant abutment-level impressions. Splinting had no effect on the accuracy of implant impressions. © 2018 John Wiley & Sons Australia, Ltd.

  17. On stress/strain shielding and the material stiffness paradigm for dental implants.

    Science.gov (United States)

    Korabi, Raoof; Shemtov-Yona, Keren; Rittel, Daniel

    2017-10-01

    Stress shielding considerations suggest that the dental implant material's compliance should be matched to that of the host bone. However, this belief has not been confirmed from a general perspective, either clinically or numerically. To characterize the influence of the implant stiffness on its functionality using the failure envelope concept that examines all possible combinations of mechanical load and application angle for selected stress, strain and displacement-based bone failure criteria. Those criteria represent bone yielding, remodeling, and implant primary stability, respectively MATERIALS AND METHODS: We performed numerical simulations to generate failure envelopes for all possible loading configurations of dental implants, with stiffness ranging from very low (polymer) to extremely high, through that of bone, titanium, and ceramics. Irrespective of the failure criterion, stiffer implants allow for improved implant functionality. The latter reduces with increasing compliance, while the trabecular bone experiences higher strains, albeit of an overall small level. Micromotions remain quite small irrespective of the implant's stiffness. The current paradigm favoring reduced implant material's stiffness out of concern for stress or strain shielding, or even excessive micromotions, is not supported by the present calculations, that point exactly to the opposite. © 2017 Wiley Periodicals, Inc.

  18. Production and Characterization of Glass-Ceramic Materials for Potential Use in Dental Applications: Thermal and Mechanical Properties, Microstructure, and In Vitro Bioactivity

    Directory of Open Access Journals (Sweden)

    Francesco Baino

    2017-12-01

    Full Text Available Multicomponent silicate glasses and their corresponding glass-ceramic derivatives were prepared and tested for potential applications in dentistry. The glasses were produced via a melting-quenching process, ground and sieved to obtain fine-grained powders that were pressed in the form of small cylinders and thermally treated to obtain sintered glass-ceramic samples. X-ray diffraction investigations were carried out on the materials before and after sintering to detect the presence of crystalline phases. Thermal analyses, mechanical characterizations (assessment of bending strength, Young’s modulus, Vickers hardness, fracture toughness, and in vitro bioactivity tests in simulated body fluid were performed. On the basis of the acquired results, different potential applications in the dental field were discussed for the proposed glass-ceramics. The use of such materials can be suggested for either restorative dentistry or dental implantology, mainly depending on their peculiar bioactive and mechanical properties. At the end of the work, the feasibility of a novel full-ceramic bilayered implant was explored and discussed. This implant, comprising a highly bioactive layer expected to promote osteointegration and another one mimicking the features of tooth enamel, can have an interesting potential for whole tooth substitution.

  19. Mechanical properties of provisional dental materials: A systematic review and meta-analysis.

    Science.gov (United States)

    Astudillo-Rubio, Daniela; Delgado-Gaete, Andrés; Bellot-Arcís, Carlos; Montiel-Company, José María; Pascual-Moscardó, Agustín; Almerich-Silla, José Manuel

    2018-01-01

    Provisional restorations represent an important phase during the rehabilitation process, knowledge of the mechanical properties of the available materials allows us to predict their clinical performance. At present, there is no systematic review, which supports the clinicians' criteria, in the selection of a specific material over another for a particular clinical situation. The purpose of this systematic review and meta-analysis was to assess and compare the mechanical properties of dimethacrylates and monomethacrylates used in fabricating direct provisional restorations, in terms of flexural strength, fracture toughness and hardness. This review followed the PRISMA guidelines. The searches were conducted in PubMed, Embase, Web of Science, Scopus, the New York Academy of Medicine Grey Literature Report and were complemented by hand-searching, with no limitation of time or language up to January 10, 2017. Studies that assess and compare the mechanical properties of dimethacrylate- and monomethacrylate-based provisional restoration materials were selected. A quality assessment of full-text articles were performed according to modified ARRIVE and CONSORT criteria and modified Cochrane Collaboration's tool for in vitro studies. Initially, 256 articles were identified. After removing the duplicates and applying the selection criteria, 24 articles were included in the qualitative synthesis and 7 were included in the quantitative synthesis (meta-analysis). It may be concluded that dimethacrylate-based provisional restorations presented better mechanical behavior than monomethacrylate-based ones in terms of flexural strength and hardness. Fracture toughness showed no significant differences. Within the monomethacrylate group, polymethylmethacrylate showed greater flexural strength than polyethylmethacrylate.

  20. Mechanical properties of provisional dental materials: A systematic review and meta-analysis.

    Directory of Open Access Journals (Sweden)

    Daniela Astudillo-Rubio

    Full Text Available Provisional restorations represent an important phase during the rehabilitation process, knowledge of the mechanical properties of the available materials allows us to predict their clinical performance. At present, there is no systematic review, which supports the clinicians' criteria, in the selection of a specific material over another for a particular clinical situation. The purpose of this systematic review and meta-analysis was to assess and compare the mechanical properties of dimethacrylates and monomethacrylates used in fabricating direct provisional restorations, in terms of flexural strength, fracture toughness and hardness. This review followed the PRISMA guidelines. The searches were conducted in PubMed, Embase, Web of Science, Scopus, the New York Academy of Medicine Grey Literature Report and were complemented by hand-searching, with no limitation of time or language up to January 10, 2017. Studies that assess and compare the mechanical properties of dimethacrylate- and monomethacrylate-based provisional restoration materials were selected. A quality assessment of full-text articles were performed according to modified ARRIVE and CONSORT criteria and modified Cochrane Collaboration's tool for in vitro studies. Initially, 256 articles were identified. After removing the duplicates and applying the selection criteria, 24 articles were included in the qualitative synthesis and 7 were included in the quantitative synthesis (meta-analysis. It may be concluded that dimethacrylate-based provisional restorations presented better mechanical behavior than monomethacrylate-based ones in terms of flexural strength and hardness. Fracture toughness showed no significant differences. Within the monomethacrylate group, polymethylmethacrylate showed greater flexural strength than polyethylmethacrylate.

  1. A Review on Dental Amalgam Corrosion and Its Consequences

    Directory of Open Access Journals (Sweden)

    M Fathi

    2004-02-01

    Full Text Available Dental amalgam is still the most useful restorative material for posterior teeth and has been successfully used for over a century. Dental amalgam has been widely used as a direct filling material due to its favorable mechanical properties as well as low cost and easy placement. However, the mercury it contains raises concerns about its biological toxicity and environmental hazard. Although in use for more than 150 years, dental amalgam has always been suspected more or less vigorously due to its alleged health hazard. Amalgam restorations often tarnish and corrode in oral environment. Corrosion of dental amalgam can cause galvanic action. Ion release as a result of corrosion is most important. Humans are exposed to mercury and other main dental metals via vapor or corrosion products in swallowed saliva and also direct absorption into blood from oral mucosa. During recent decades the use of dental amalgam has been discussed with respect to potential toxic effects of mercury components. In this article, the mechanisms of dental amalgam corrosion are described and results of researches are reviewed. It finally covers the corrosion of amalgams since this is the means by which metals, including mercury, can be released within oral cavity. Keywords: Dental amalgam, Amalgam corrosion, Biocompatibility, Mercury release, Amalgam restoration

  2. Effect of the cavity configuration factor on the marginal microleakage of esthetic restorative materials.

    Science.gov (United States)

    Franco, Eduardo Batista; Gonzaga Lopes, Lawrence; Lia Mondelli, Rafael Francisco; da Silva e Souza, Mário Honorato; Pereira Lauris, José Roberto

    2003-06-01

    To evaluate the effect of the cavity configuration factor (CF) on the marginal microleakage of cervical restorations with four aesthetic restorative materials. Conventional cavities, 2.9 mm in diameter and 1.5 mm deep, with CF=2.7 and "saucer"-shaped ones with CF=2 were created in 60 extracted premolars. The following groups were established: G1: Z100/Single Bond, G2: Freedom/Stae, G3: Vitremer/Primer and G4: Durafill/Durafill Bond, following each manufacturer's directions. Thermocycling of the specimens was performed in an aqueous solution of 2% buffered methylene blue, with the temperature varying between 5 to 55 degrees C, for a total of cycles of 60 minutes per day, for 7 days. The specimens were then sectioned and evaluated by two observers using photographs acquired from a stereomicroscope. The values were subjected to Kruskal-Wallis analysis and the Dunn and Wilcoxon test. The averages of the microleakage scores observed in the conventional and "saucer"-shaped cavities were respectively: G1: 0.66/0.46; G2: 0.92/0.69; G3: 1.8/1.86; G4: 3.54/2.3.

  3. The effect of aging on the fracture toughness of esthetic restorative materials.

    Science.gov (United States)

    Bagheri, Rafat; Azar, Mohammad R; Tyas, Martin J; Burrow, Michael F

    2010-06-01

    To compare the fracture toughness (KIc) of tooth-colored restorative materials based on a four-point bending; to assess the effect of distilled water and a resin surface sealant (G-Coat Plus) on the resistance of the materials to fracture. Specimens were prepared from six materials: Quix Fil; Dyract (Dentsply), Freedom (SDI), Fuji VII (GC), Fuji IX (GC); Fuji II LC (GC). Fuji II LC and Fuji IX were tested both with and without applying G-Coat Plus (GC). The specimens were divided into the three groups which were conditioned in distilled water at 37 degrees C for 48 hours, 4 and 8 weeks. The specimens were loaded in a four-point bending test using a universal testing machine. The maximum load to specimen failure was recorded and the fracture toughness calculated. There were significant differences among most of the materials (P G-Coat Plus affected Fuji II LC positively while it had no effect on the Fuji IX.

  4. Information resources and material selection in bonded restorations among Korean dentists.

    Science.gov (United States)

    Chang, Juhea; Kim, Hae-Young; Cho, Byeong Hoon; Lee, In Bog; Son, Ho Hyun

    2009-12-01

    To elucidate how dentists access knowledge sources when choosing adhesive agents for bonded restoration and whether these resources influenced the selection of materials. A national survey was carried out involving dentists in South Korea. The questionnaire included the status of the operator, clinical techniques, and materials. A total of 12,193 e-mails were distributed, 2632 were opened by recipients, and 840 responses were collected. For primary information resources in material selection, 55.8% (n = 469) of the responders mentioned continuing education. This selection criteria varied according to the working status of the clinician (p choice of bonding system was influenced by of the length of the career (p < 0.0001), and the preferred bonding systems differed according to the source of the information (p = 0.035). The popular bonding systems were not ranked according to the bonding strategy, but a preference was found for specific brands or manufacturers. To decrease the confusion of clinicians related to the selection of bonding materials, evidence-based guidelines need to be comprehensibly organized and efficiently approached in clinics.

  5. The use of cone beam computed tomography and three dimensional printing technology in the restoration of a maxillectomy patient using a dental implant retained obturator.

    Science.gov (United States)

    Michelinakis, George

    2017-01-01

    This case report presents an alternative method for fabricating an obturator for patients that develop xerostomia and mild trismus following radiation to the Head and Neck region. Multiple initial impression stages are avoided leading to less irritation to soft tissues and less discomfort to the patient. A 69-year-old male patient was referred to our dental practice by the Maxillofacial Surgery Department of the local General Hospital. The patient had undergone a right maxillectomy for removal of a Squamous Cell Carcinoma 2 weeks prior. Four endosseous dental implants were placed in the remaining upper jaw and 2 implants were inserted into the canine region of his edentulous mandible 3 weeks after ablative surgery. Five months following completion of radiotherapy and chemotherapy, a cone beam computed tomography of the maxilla was obtained, and a three dimensional model was constructed using an appropriate resin. Using the model as the detailed primary cast, a custom acrylic special tray was fabricated for the final impression of the remaining maxilla and the maxillary defect. An implant retained maxillary obturator and an implant retained mandibular overdenture were constructed to restore patient's speech, mastication and deglutition. The method presented here can limit the impression stages needed for construction of a maxillary obturator prosthesis to a single impression procedure advocating a partial digital workflow process. This can be very beneficial to the patient suffering from postradiation side-effects such as trismus, mucositis, and xerostomia.

  6. The use of cone beam computed tomography and three dimensional printing technology in the restoration of a maxillectomy patient using a dental implant retained obturator

    Directory of Open Access Journals (Sweden)

    George Michelinakis

    2017-01-01

    Full Text Available This case report presents an alternative method for fabricating an obturator for patients that develop xerostomia and mild trismus following radiation to the Head and Neck region. Multiple initial impression stages are avoided leading to less irritation to soft tissues and less discomfort to the patient. A 69-year-old male patient was referred to our dental practice by the Maxillofacial Surgery Department of the local General Hospital. The patient had undergone a right maxillectomy for removal of a Squamous Cell Carcinoma 2 weeks prior. Four endosseous dental implants were placed in the remaining upper jaw and 2 implants were inserted into the canine region of his edentulous mandible 3 weeks after ablative surgery. Five months following completion of radiotherapy and chemotherapy, a cone beam computed tomography of the maxilla was obtained, and a three dimensional model was constructed using an appropriate resin. Using the model as the detailed primary cast, a custom acrylic special tray was fabricated for the final impression of the remaining maxilla and the maxillary defect. An implant retained maxillary obturator and an implant retained mandibular overdenture were constructed to restore patient's speech, mastication and deglutition. The method presented here can limit the impression stages needed for construction of a maxillary obturator prosthesis to a single impression procedure advocating a partial digital workflow process. This can be very beneficial to the patient suffering from postradiation side-effects such as trismus, mucositis, and xerostomia.

  7. Dental OCT

    Science.gov (United States)

    Wilder-Smith, Petra; Otis, Linda; Zhang, Jun; Chen, Zhongping

    This chapter describes the applications of OCT for imaging in vivo dental and oral tissue. The oral cavity is a diverse environment that includes oral mucosa, gingival tissues, teeth and their supporting structures. Because OCT can image both hard and soft tissues of the oral cavity at high resolution, it offers the unique capacity to identity dental disease before destructive changes have progressed. OCT images depict clinically important anatomical features such as the location of soft tissue attachments, morphological changes in gingival tissue, tooth decay, enamel thickness and decay, as well as the structural integrity of dental restorations. OCT imaging allows for earlier intervention than is possible with current diagnostic modalities.

  8. Laboratory Performance of Universal Adhesive Systems for Luting CAD/CAM Restorative Materials.

    Science.gov (United States)

    Siqueira, Fabiana; Cardenas, Andres Millan; Gutierrez, Mario Felipe; Malaquias, Pâmela; Hass, Viviane; Reis, Alessandra; Loguercio, Alessandro D; Perdigão, Jorge

    To evaluate the microshear bond strength (μSBS) of several universal adhesive systems applied on five different indirect restorative materials. Five CAD/CAM materials were selected: 1) indirect resin composite (LAV); 2) feldspathic glass ceramic (VTR); 3) leucite-reinforced glass-ceramic (EMP); 4) lithium disilicate ceramic (EMX); 5) yttrium-stabilized zirconium dioxide (CZI). For each material, 15 blocks were cut into 4 rectangular sections (6 × 6 × 6 mm) (n = 60 per group), and processed as recommended by the respective manufacturer. For each indirect material, the following adhesive systems were applied according to the respective manufacturer's instructions: 1) AdheSE Universal [ADU]; 2) All-Bond Universal (ABU); 3) Ambar Universal (AMB); 4) Clearfil Universal (CFU); 5) Futurabond U (FBU); 6) One Coat 7 Universal (OCU); 7) Peak Universal Bond (PUB); 8) Prime&Bond Elect (PBE); 9) Scotchbond Universal Adhesive (SBU); 10) Xeno Select (XEN, negative control). After the application of the adhesive system, cylinder-shaped transparent matrices were filled with a dual-curing resin cement (NX3) and light cured. Specimens were stored in water (37°C for 24 h) and tested in shear mode at 1.0 mm/min (mSBS). The failure pattern and μSBS were statistically evaluated (a = 0.05). LAV, VTR, and EMP showed a greater number of cohesive fractures than EMX and CZI (p materials. There was a wide variability in mean μSBS when different universal adhesives were applied to the several CAD/CAM indirect materials. Most universal adhesives bonded well to air-abraded zirconia.

  9. Comparison of the color stability of provisional restorative materials after storing in different drinks

    Directory of Open Access Journals (Sweden)

    Merve Bankoğlu Güngör

    2016-05-01

    Full Text Available OBJECTIVE: The objective of the present study was to compare the color stability of provisional restorative materials after stroring in different drinks. MATERIALS AND METHOD: Thirty specimens (10 mm in diameter and 2 mm in thickness were prepared from three different materials (Temdent, TRIAD ve TelioCAD. Specimens were divided into six groups according to drinks (distilled water, coffee, tea, cola, red wine and fruit juice; n=5. Specimens were stored in these drinks at 37 °C for 48 hours. The L*, a*, b* values of the specimens were measured with a spectrophometer and recorded before and after storing in drinks. Then ΔE* values were calculated. The data were statistically analyzed using two-way analysis of variance (ANOVA and Tukey’s HSD post hoc tests (α=0.05. RESULTS: Difference between the ΔE* values of specimens stored in different drinks was statistically significant (p<0.05. Color change of TelioCAD specimens was smallest in cola drink and greatest in red wine. Color change of Temdent specimens was smallest in fruit juice and greatest in coffee. For TRIAD specimens, greater color change was observed in coffee, red wine, and tea, in descending order. When the results of storing in the same drink were compared, TRIAD showed the greatest values of color change in coffee and red wine in comparison to the other provisional materials (p<0.05. CONCLUSION: Color stability changed according to the type of the provisional material and the drink. When the drinks were evaluated, greater color changes were observed in coffee, and when the materials were evaluated greater color changes were observed in TRIAD.

  10. Shear bond strength of bulk-fill and nano-restorative materials to dentin.

    Science.gov (United States)

    Colak, Hakan; Ercan, Ertugrul; Hamidi, Mehmet Mustafa

    2016-01-01

    Bulk-fill composite materials are being developed for preparation depths of up to 4 mm in an effort to simplify and improve the placement of direct composite posterior restorations. The aim of our study was to compare shear-bond strength of bulk-fill and conventional posterior composite resins. In this study, 60 caries free extracted human molars were used and sectioned parallel to occlusal surface to expose midcoronal dentin. The specimens were randomly divided into four groups. Total-etch dentine bonding system (Adper Scotchbond 1XT, 3M ESPE) was applied to dentin surface in all the groups to reduce variability in results. Then, dentine surfaces covered by following materials. Group I: SonicFill Bulk-Fill, Group II: Tetric EvoCeram (TBF), Group III: Herculite XRV Ultra, and Group IV: TBF Bulk-Fill, 2 mm × 3 mm cylindrical restorations were prepared by using application apparatus. Shear bond testing was measured by using a universal testing machine. Kruskal-Wallis and Mann-Whitney U-tests were performed to evaluate the data. The highest value was observed in Group III (14.42 ± 4.34) and the lowest value was observed in Group IV (11.16 ± 2.76) and there is a statistically significant difference between these groups (P = 0.046). However, there is no statistically significant difference between the values of other groups. In this study, Group III was showed higher strength values. There is a need for future studies about long-term bond strength and clinical success of these adhesive and bulk-fill systems.

  11. Characteristics of pristine volcanic materials: Beneficial and harmful effects and their management for restoration of agroecosystem.

    Science.gov (United States)

    Anda, Markus; Suparto; Sukarman

    2016-02-01

    Eruption of Sinabung volcano in Indonesia began again in 2010 after resting for 1200 years. The volcano is daily emitting ash and pyroclastic materials since September 2013 to the present, damaging agroecosystems and costing for management restoration. The objective of the study was to assess properties and impacts of pristine volcanic material depositions on soil properties and to provide management options for restoring the affected agroecosytem. Land satellite imagery was used for field studies to observe the distribution, thickness and properties of ashfall deposition. The pristine ashfall deposits and the underlying soils were sampled for mineralogical, soluble salt, chemical, physical and toxic compound analyses. Results showed that uneven distribution of rainfall at the time of violent eruption caused the areas receiving mud ashfall developed surface encrustation, which was not occur in areas receiving dry ashfall. Ashfall damaged the agroecosytem by burning vegetation, forming surface crusts, and creating soil acidity and toxicity. X-ray diffraction (XRD) and scanning electron microscope (SEM) analyses of encrustated layer indicated the presence of gypsum and jarosite minerals. Gypsum likely acted as a cementing agent in the formation of the encrustation layer with extremely low pH (2.9) and extremely high concentrations of Al, Ca and S. Encrustation is responsible for limited water infiltration and root penetration, while the extremely high concentration of Al is responsible for crop toxicity. Mud ashfall and dry ashfall deposits also greatly changed the underlying soil properties by decreasing soil pH and cation exchange capacity and by increasing exchangeable Ca, Al, and S availability. Despite damaging vegetation in the short-term, the volcanic ashfall enriched the soil in the longer term by adding nutrients like Ca, Mg, K, Na, P, Si and S. Suggested management practices to help restore the agroecosystem after volcanic eruptions include: (i) the

  12. Fluorides leaching from restorative materials and the effect on adjacent teeth

    DEFF Research Database (Denmark)

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

    2010-01-01

    Placing a Class II restoration in a tooth changes the local environment, including that for the adjacent tooth. Apart from the change to a less- or non-cariogenic environment for the restored tooth, the effect of leachable components from a restoration in the adjacent tooth should be taken into c...

  13. Direct restorative treatment of dental erosion caused by gastroesophageal reflux disease associated with bruxism: a case report

    OpenAIRE

    Vidal, Cristina de Mattos Pimenta [UNESP; Catelan, Anderson [UNESP; Briso, André Luiz Fraga [UNESP; Santos, Paulo Henrique dos [UNESP

    2011-01-01

    Gastroesophageal reflux disease (GERD) is a gastrointestinal disorder in which stomach acids are chronically regurgitated into the esophagus and oral cavity. Continual exposure of the teeth to these acids can cause severe tooth wear. Dentists are often the first healthcare professionals to diagnose dental erosion in patients with GERD. This article presents a case report of a 27-year-old male smoker with tooth wear and dentin sensitivity caused by GERD associated with bruxism. After diagnosis...

  14. Resin-composite blocks for dental CAD/CAM applications.

    Science.gov (United States)

    Ruse, N D; Sadoun, M J

    2014-12-01

    Advances in digital impression technology and manufacturing processes have led to a dramatic paradigm shift in dentistry and to the widespread use of computer-aided design/computer-aided manufacturing (CAD/CAM) in the fabrication of indirect dental restorations. Research and development in materials suitable for CAD/CAM applications are currently the most active field in dental materials. Two classes of materials are used in the production of CAD/CAM restorations: glass-ceramics/ceramics and resin composites. While glass-ceramics/ceramics have overall superior mechanical and esthetic properties, resin-composite materials may offer significant advantages related to their machinability and intra-oral reparability. This review summarizes recent developments in resin-composite materials for CAD/CAM applications, focusing on both commercial and experimental materials. © International & American Associations for Dental Research.

  15. State-of-the-art techniques in operative dentistry: contemporary teaching of posterior composites in UK and Irish dental schools.

    LENUS (Irish Health Repository)

    Lynch, C D

    2010-08-14

    Advances of composite systems and their application have revolutionised the management of posterior teeth affected by caries, facilitating a minimally invasive approach. Previous surveys have indicated that the teaching of posterior composites within dental schools was developing, albeit not keeping pace with clinical evidence and the development of increasingly predictable techniques and