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Sample records for dental veneers

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

    PubMed Central

    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. PMID:23674920

  2. Thermal-induced residual stresses affect the fractographic patterns of zirconia-veneer dental prostheses.

    PubMed

    Belli, Renan; Petschelt, Anselm; Lohbauer, Ulrich

    2013-05-01

    Veneer fractures in dental zirconia-veneer prostheses are more frequent clinically than in conventional metal-ceramic systems. This is thought to be due to the increased residual stresses generated within the veneer during fabrication when zirconia is the infrastructure material. This investigation aimed to analyze the fractographic features of fractured zirconia-veneer dental crowns submitted to a load-to-failure test and to a more clinically relevant in vitro chewing simulation fatigue test. As-sintered and sandblasted zirconia copings were veneered with glass-ceramic with different coefficients of thermal expansion and cooled following two cooling rates, creating, this way, different levels of stresses within the veneer. Crowns with different thermal mismatch combinations and different cooling rates were hypothesized to present particular fracture patterns. A careful examination of >1000 scanning electron microscopy images of the fracture surfaces was conducted in search of characteristic fractographic markings of fracture mechanisms connected to the stress state of the veneer. Distinctive structural features could be observed between groups veneered with the two different glass-ceramics and between fractured crowns under static and cyclic loading. The presence/absence of residual stresses zones within the veneer have shown to play the major role in the fracture pattern of zirconia-veneer dental prostheses. For the fatigue crowns, the zirconia core was never exposed, either for sandblasted and as-sintered groups.

  3. Tribological behaviour of unveneered and veneered lithium disilicate dental material.

    PubMed

    Figueiredo-Pina, C G; Patas, N; Canhoto, J; Cláudio, R; Olhero, S M; Serro, A P; Ferro, A C; Guedes, M

    2016-01-01

    The friction and wear behaviour of a lithium disilicate dental ceramic against natural dental enamel is studied, including the effect of the presence of a fluorapatite veneering upon the tribological properties of the material. The tribological behaviour was assessed using reciprocating pin-on-plate test configuration, at pH 3 and pH 7. The surface energy of the plates was determined, as well as the zeta potential of fluorapatite, lithium disilicate and enamel particles in artificial saliva. It was found that the friction and wear behaviour of the tested enamel/plate material tribocouples is less severe in unveneered plates. Initial surface roughness of the plate does not affect wear results. However the topography of the resulting wear track affects the corresponding wear loss: a smoother final wear track is associated with lower wear. The surface topography of the wear track, and thus the tribological performance of the tested materials, is very sensitive to the pH of the sliding solution. This is because the dissolution trend, wettability and surface charge of the used materials are pH dependent. Overall friction and wear are higher under basic pH conditions, especially when plates are veneered. A wear model is proposed that correlates the effect of the described parameters with the observed tribological behaviour at pH 7. Attained results show that fluorapatite coating of lithium disilicate dental crowns affects tooth/crown wear behaviour, resulting in increased wear of both the artificial crown and the opposing natural teeth. Coating should therefore be avoided in occlusal crown surfaces.

  4. Thermally induced fracture for core-veneered dental ceramic structures.

    PubMed

    Zhang, Zhongpu; Guazzato, Massimiliano; Sornsuwan, Tanapon; Scherrer, Susanne S; Rungsiyakull, Chaiy; Li, Wei; Swain, Michael V; Li, Qing

    2013-09-01

    Effective and reliable clinical uses of dental ceramics necessitate an insightful analysis of the fracture behaviour under critical conditions. To better understand failure characteristics of porcelain veneered to zirconia core ceramic structures, thermally induced cracking during the cooling phase of fabrication is studied here by using the extended finite element method (XFEM). In this study, a transient thermal analysis of cooling is conducted first to determine the temperature distributions. The time-dependent temperature field is then imported to the XFEM model for viscoelastic thermomechanical analysis, which predicts thermally induced damage and cracking at different time steps. Temperature-dependent material properties are used in both transient thermal and thermomechanical analyses. Three typical ceramic structures are considered in this paper, namely bi-layered spheres, squat cylinders and dental crowns with thickness ratios of either 1:2 or 1:1. The XFEM fracture patterns exhibit good agreement with clinical observation and the in vitro experimental results obtained from scanning electron microscopy characterization. The study reveals that fast cooling can lead to thermal fracture of these different bi-layered ceramic structures, and cooling rate (in terms of heat transfer coefficient) plays a critical role in crack initiation and propagation. By exploring different cooling rates, the heat transfer coefficient thresholds of fracture are determined for different structures, which are of clear clinical implication.

  5. Veneers

    MedlinePlus

    ... History of Dental Advances What is a Composite Resin (White Filling)? Headaches and Jaw Pain? Check Your ... thin shells of ceramic (porcelain) or a composite resin material, which are bonded to the front of ...

  6. Fabrication of Silicon Nitride Dental Core Ceramics with Borosilicate Veneering material

    NASA Astrophysics Data System (ADS)

    Wananuruksawong, R.; Jinawath, S.; Padipatvuthikul, P.; Wasanapiarnpong, T.

    2011-10-01

    Silicon nitride (Si3N4) ceramic is a great candidate for clinical applications due to its high fracture toughness, strength, hardness and bio-inertness. This study has focused on the Si3N4 ceramic as a dental core material. The white Si3N4 was prepared by pressureless sintering at relative low sintering temperature of 1650 °C in nitrogen atmosphere. The coefficient of thermal expansion (CTE) of Si3N4 ceramic is lower than that of Zirconia and Alumina ceramic which are popular in this field. The borosilicate glass veneering was employed due to its compatibility in thermal expansion. The sintered Si3N4 specimens represented the synthetic dental core were paintbrush coated by a veneer paste composed of borosilicate glass powder (<150 micrometer, Pyrex) with 5 wt% of zirconia powder (3 wt% Y2O3 - partial stabilized zirconia) and 30 wt% of polyvinyl alcohol (5 wt% solution). After coating the veneer on the Si3N4 specimens, the firing was performed in electric tube furnace between 1000-1200°C. The veneered specimens fired at 1100°C for 15 mins show good bonding, smooth and glossy without defect and crazing. The veneer has thermal expansion coefficient as 3.98×10-6 °C-1, rather white and semi opaque, due to zirconia addition, the Vickers hardness as 4.0 GPa which is closely to the human teeth.

  7. Illuminating light-dependent color shifts in core and veneer layers of dental all-ceramics.

    PubMed

    Lee, Yong-Keun; Cha, Hyun-Suk; Yu, Bin

    2014-09-01

    The color of an object is perceived differently depending on the ambient light conditions. Since dental all-ceramic restorations are fabricated by building up several layers to reproduce the tooth shade, the optical properties of each layer should be optimized for successful shade reproduction. This study aimed to determine the separate contributions of the color shifts in each of the core and veneer layers of all-ceramics by switching the illuminating lights on the color shifts of layered ceramics. Specimens of seven kinds of core ceramics and the corresponding veneer ceramics for each core were fabricated with a layered thickness of 1.5 mm. A sintering ceramic was used as a reference core material. The Commission Internationale de l’Eclairage (CIE) color coordinates of core, veneer, and layered specimens were measured with a spectroradiometer under the CIE illuminant D65 (daylight), A (incandescent lamp), and F9 (fluorescent lamp) simulating lights. Color shifts of the layered specimens were primarily determined by the CIE a shifts (D65 to A switch) or by the CIE b shifts (D65 to F9 switch) of the veneer layer. The color coordinates shifts in the constituent layers differentially influenced those of the layered specimens by the kind of switched lights. Therefore, the optical properties of the constituent layers of all-ceramics should be controlled to reflect these findings.

  8. Effect of metal primers and tarnish treatment on bonding between dental alloys and veneer resin

    PubMed Central

    Choo, Seung-Sik; Huh, Yoon-Hyuk; Cho, Lee-Ra

    2015-01-01

    PURPOSE The aim of this study was to evaluate the effect of metal primers on the bonding of dental alloys and veneer resin. Polyvinylpyrrolidone solution's tarnish effect on bonding strength was also investigated. MATERIALS AND METHODS Disk-shape metal specimens (diameter 8 mm, thickness 1.5 mm) were made from 3 kinds of alloy (Co-Cr, Ti and Au-Ag-Pd alloy) and divided into 4 groups per each alloy. Half specimens (n=12 per group) in tarnished group were immersed into polyvinylpyrrolidone solution for 24 hours. In Co-Cr and Ti-alloy, Alloy Primer (MDP + VBATDT) and MAC-Bond II (MAC-10) were applied, while Alloy Primer and V-Primer (VBATDT) were applied to Au-Ag-Pd alloys. After surface treatment, veneering composite resin were applied and shear bond strength test were conducted. RESULTS Alloy Primer showed higher shear bond strength than MAC-Bond II in Co-Cr alloys and Au-Ag-Pd alloy (P<.05). However, in Ti alloy, there was no significant difference between Alloy Primer and MAC-Bond II. Tarnished Co-Cr and Au-Ag-Pd alloy surfaces presented significantly decreased shear bond strength. CONCLUSION Combined use of MDP and VBATDT were effective in bonding of the resin to Co-Cr and Au-Ag-Pd alloy. Tarnish using polyvinylpyrrolidone solution negatively affected on the bonding of veneer resin to Co-Cr and Au-Ag-Pd alloys. PMID:26576256

  9. Replacement of missing lateral incisors with lithium disilicate glass-ceramic veneer-fixed dental prostheses: a clinical report

    PubMed Central

    Bissasu, Sami M; Al-houri, Nabil A

    2014-01-01

    Key Clinical Message This report describes the use of lithium disilicate glass-ceramic veneer-fixed dental prostheses in replacing congenitally missing maxillary lateral incisors. This kind of prosthesis has an advantage over a lingual-retainer resin-bonded fixed dental prosthesis in its capability of changing the color and shape of the abutment teeth. The prostheses provided an acceptable esthetics and comfort for the patient. PMID:25356269

  10. Effect of frame design and veneering material on biomechanical behavior of zirconia dental crowns veneered with overpressing ceramics.

    PubMed

    Porojan, Liliana; Topală, Florin; Porojan, Sorin; Savencu, Cristina

    2017-02-01

    The objective of this investigation was to compare alternative framework designs of molar zirconia crowns veneered with various overpressing ceramics and to predict the biomechanical behavior based on the stress evaluation. The hypothesis of the study is that the zirconia framework design and type of the veneering material, using the same technological procedure, may influence the biomechanical behavior of the restorations. Three geometric models with differential coping designs (uniform thickness, cutback and buccal reduction) were developed and two types of hot-pressed ceramics (leucite and lithium disilicate reinforced) were analyzed for the veneers. Using finite element analysis (FEA), maximum principle stresses were recorded in the tooth structures and in the restorations for all the developed designs. Results led to the conclusion that the hypothesis was accepted.

  11. Fracture and shear bond strength analyses of different dental veneering ceramics to zirconia.

    PubMed

    Diniz, Alexandre C; Nascimento, Rubens M; Souza, Julio C M; Henriques, Bruno B; Carreiro, Adriana F P

    2014-05-01

    The purpose of this work was to evaluate the interaction of different layering porcelains with zirconia via shear bond strength test and microscopy. Four different groups of dental veneering porcelains (VM9, Zirkonzanh, Ceramco, IPS) were fused onto forty zirconia-based cylindrical substrates (8mm in diameter and 12 mm in height) (n=10), according to the manufacturer's recommendations. Additionally, layered dental porcelain (D-sign, Ivoclar) was fired on ten Ni-Cr cylindrical substrates Shear bond strength tests of the veneering porcelain to zirconia or Ni-Cr were carried out at a crosshead speed of 0.5mm/min. After the shear bond tests, the interfaces were analyzed by scanning electron microscopy (SEM). The fracture type exhibited by the different systems was also assessed. The results were statistically analyzed by ANOVA at a significant level of p<.05. The shear bond strength values of the porcelain-to-NiCr interfaces (25.3±7.1 MPa) were significantly higher than those recorded for the following porcelain-to-zirconia systems: Zirkonzanh (18.8±1 MPa), Ceramco (18.2±4.7 MPa), and IPS (16±4.5 MPa). However, no significant differences were found in the shear bond strength values between the porcelain-to-NiCr and porcelain (VM9)-to-zirconia (23.2±5.1 MPa) groups (p>.05). All-ceramic interfaces revealed mixed failure type, cohesive in the porcelain and adhesive at the interface. This study demonstrated that all-ceramic systems do not attain yet the same bond strength standards equivalent to metal-ceramic systems. Therefore, despite the esthetic appeal of all-ceramic restorations, the adhesion between the porcelain and zirconia framework is still an issue considering the long term success of the restoration.

  12. Reliability and failure modes of implant-supported zirconium-oxide fixed dental prostheses related to veneering techniques

    PubMed Central

    Baldassarri, Marta; Zhang, Yu; Thompson, Van P.; Rekow, Elizabeth D.; Stappert, Christian F. J.

    2011-01-01

    Summary Objectives To compare fatigue failure modes and reliability of hand-veneered and over-pressed implant-supported three-unit zirconium-oxide fixed-dental-prostheses(FDPs). Methods Sixty-four custom-made zirconium-oxide abutments (n=32/group) and thirty-two zirconium-oxide FDP-frameworks were CAD/CAM manufactured. Frameworks were veneered with hand-built up or over-pressed porcelain (n=16/group). Step-stress-accelerated-life-testing (SSALT) was performed in water applying a distributed contact load at the buccal cusp-pontic-area. Post failure examinations were carried out using optical (polarized-reflected-light) and scanning electron microscopy (SEM) to visualize crack propagation and failure modes. Reliability was compared using cumulative-damage step-stress analysis (Alta-7-Pro, Reliasoft). Results Crack propagation was observed in the veneering porcelain during fatigue. The majority of zirconium-oxide FDPs demonstrated porcelain chipping as the dominant failure mode. Nevertheless, fracture of the zirconium-oxide frameworks was also observed. Over-pressed FDPs failed earlier at a mean failure load of 696 ± 149 N relative to hand-veneered at 882 ± 61 N (profile I). Weibull-stress-number of cycles-unreliability-curves were generated. The reliability (2-sided at 90% confidence bounds) for a 400N load at 100K cycles indicated values of 0.84 (0.98-0.24) for the hand-veneered FDPs and 0.50 (0.82-0.09) for their over-pressed counterparts. Conclusions Both zirconium-oxide FDP systems were resistant under accelerated-life-time-testing. Over-pressed specimens were more susceptible to fatigue loading with earlier veneer chipping. PMID:21557985

  13. Fracture Toughness of Veneering Ceramics for Fused to Metal (PFM) and Zirconia Dental Restorative Materials

    PubMed Central

    Quinn, Janet B.; Quinn, George D.; Sundar, Veeraraghaven

    2010-01-01

    Veneering ceramics designed to be used with modern zirconia framework restorations have been reported to fracture occasionally in vivo. The fracture toughness of such veneering ceramics was measured and compared to that of conventional feldspathic porcelain veneering ceramics for metal framework restorations. The fracture toughness of the leucite free veneer was measured to be 0.73 MPa m ± 0.02 MPa m, which is less than that for the porcelain fused to metal (PFM) veneering ceramic: 1.10 MPa ± 0.2 MPa. (Uncertainties are one standard deviation unless otherwise noted.) The surface crack in flexure (SCF) method was suitable for both materials, but precrack identification was difficult for the leucite containing feldspathic porcelain PFM veneer. PMID:21833158

  14. Failure modes and fracture origins of porcelain veneers on bilayer dental crowns.

    PubMed

    Liu, Yihong; Liu, Guanghua; Wang, Yong; Shen, James Zhijian; Feng, Hailan

    2014-01-01

    The aims of this study were to determine the fracture origins and crack paths in the porcelain of clinically failed bilayer ceramic restorations and to reveal the correlation between the porcelain failures and material properties. Three clinically failed crowns of each material (bilayer zirconia crowns, galvano-ceramic crowns, and porcelain-fused-to-metal crowns) were collected and underwent failure analysis. The fractures found in porcelain veneers showed several characteristics including wear, Hertzian cone crack, chipping off, and delamination. The results indicated that the fracture origins and features of the porcelain in bilayer ceramic restorations might be affected by the rigidity of core materials and thickness of copings.

  15. Sol–gel dip coating of yttria-stabilized tetragonal zirconia dental ceramic by aluminosilicate nanocomposite as a novel technique to improve the bonding of veneering porcelain

    PubMed Central

    Madani, Azamsadat; Nakhaei, Mohammadreza; Karami, Parisa; Rajabzadeh, Ghadir; Salehi, Sahar; Bagheri, Hossein

    2016-01-01

    The aim of this in vitro study was to evaluate the effect of silica and aluminosilicate nanocomposite coating of zirconia-based dental ceramic by a sol–gel dip-coating technique on the bond strength of veneering porcelain to the yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) in vitro. Thirty Y-TZP blocks (10 mm ×10 mm ×3 mm) were prepared and were assigned to four experimental groups (n=10/group): C, without any further surface treatment as the control group; S, sandblasted using 110 μm alumina powder; Si, silica sol dip coating + calcination; and Si/Al, aluminosilicate sol dip coating + calcination. After preparing Y-TZP samples, a 3 mm thick layer of the recommended porcelain was fired on the coated Y-TZP surface. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray analysis were used to characterize the coating and the nature of the bonding between the coating and zirconia. To examine the zirconia–porcelain bond strength, a microtensile bond strength (μTBS) approach was chosen. FT-IR study showed the formation of silica and aluminosilicate materials. XRD pattern showed the formation of new phases consisting of Si, Al, and Zr in coated samples. SEM showed the formation of a uniform coating on Y-TZP samples. Maximum μTBS values were obtained in aluminosilicate samples, which were significantly increased compared to control and sandblasted groups (P=0.013 and P<0.001, respectively). This study showed that aluminosilicate sol–gel dip coating can be considered as a convenient, less expensive reliable method for improving the bond strength between dental Y-TZP ceramics and veneering porcelain. PMID:27478376

  16. Sol-gel dip coating of yttria-stabilized tetragonal zirconia dental ceramic by aluminosilicate nanocomposite as a novel technique to improve the bonding of veneering porcelain.

    PubMed

    Madani, Azamsadat; Nakhaei, Mohammadreza; Karami, Parisa; Rajabzadeh, Ghadir; Salehi, Sahar; Bagheri, Hossein

    2016-01-01

    The aim of this in vitro study was to evaluate the effect of silica and aluminosilicate nanocomposite coating of zirconia-based dental ceramic by a sol-gel dip-coating technique on the bond strength of veneering porcelain to the yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) in vitro. Thirty Y-TZP blocks (10 mm ×10 mm ×3 mm) were prepared and were assigned to four experimental groups (n=10/group): C, without any further surface treatment as the control group; S, sandblasted using 110 μm alumina powder; Si, silica sol dip coating + calcination; and Si/Al, aluminosilicate sol dip coating + calcination. After preparing Y-TZP samples, a 3 mm thick layer of the recommended porcelain was fired on the coated Y-TZP surface. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray analysis were used to characterize the coating and the nature of the bonding between the coating and zirconia. To examine the zirconia-porcelain bond strength, a microtensile bond strength (μTBS) approach was chosen. FT-IR study showed the formation of silica and aluminosilicate materials. XRD pattern showed the formation of new phases consisting of Si, Al, and Zr in coated samples. SEM showed the formation of a uniform coating on Y-TZP samples. Maximum μTBS values were obtained in aluminosilicate samples, which were significantly increased compared to control and sandblasted groups (P=0.013 and P<0.001, respectively). This study showed that aluminosilicate sol-gel dip coating can be considered as a convenient, less expensive reliable method for improving the bond strength between dental Y-TZP ceramics and veneering porcelain.

  17. Ceramic veneers with minimum preparation.

    PubMed

    da Cunha, Leonardo Fernandes; Reis, Rachelle; Santana, Lino; Romanini, Jose Carlos; Carvalho, Ricardo Marins; Furuse, Adilson Yoshio

    2013-10-01

    The aim of this article is to describe the possibility of improving dental esthetics with low-thickness glass ceramics without major tooth preparation for patients with small to moderate anterior dental wear and little discoloration. For this purpose, a carefully defined treatment planning and a good communication between the clinician and the dental technician helped to maximize enamel preservation, and offered a good treatment option. Moreover, besides restoring esthetics, the restorative treatment also improved the function of the anterior guidance. It can be concluded that the conservative use of minimum thickness ceramic laminate veneers may provide satisfactory esthetic outcomes while preserving the dental structure.

  18. Ceramic veneers with minimum preparation

    PubMed Central

    da Cunha, Leonardo Fernandes; Reis, Rachelle; Santana, Lino; Romanini, Jose Carlos; Carvalho, Ricardo Marins; Furuse, Adilson Yoshio

    2013-01-01

    The aim of this article is to describe the possibility of improving dental esthetics with low-thickness glass ceramics without major tooth preparation for patients with small to moderate anterior dental wear and little discoloration. For this purpose, a carefully defined treatment planning and a good communication between the clinician and the dental technician helped to maximize enamel preservation, and offered a good treatment option. Moreover, besides restoring esthetics, the restorative treatment also improved the function of the anterior guidance. It can be concluded that the conservative use of minimum thickness ceramic laminate veneers may provide satisfactory esthetic outcomes while preserving the dental structure. PMID:24932126

  19. Influence of core design, production technique, and material selection on fracture behavior of yttria-stabilized tetragonal zirconia polycrystal fixed dental prostheses produced using different multilayer techniques: split-file, over-pressing, and manually built-up veneers

    PubMed Central

    Mahmood, Deyar Jallal Hadi; Linderoth, Ewa H; Wennerberg, Ann; Vult Von Steyern, Per

    2016-01-01

    Aim To investigate and compare the fracture strength and fracture mode in eleven groups of currently, the most commonly used multilayer three-unit all-ceramic yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) fixed dental prostheses (FDPs) with respect to the choice of core material, veneering material area, manufacturing technique, design of connectors, and radii of curvature of FDP cores. Materials and methods A total of 110 three-unit Y-TZP FDP cores with one intermediate pontic were made. The FDP cores in groups 1–7 were made with a split-file design, veneered with manually built-up porcelain, computer-aided design-on veneers, and over-pressed veneers. Groups 8–11 consisted of FDPs with a state-of-the-art design, veneered with manually built-up porcelain. All the FDP cores were subjected to simulated aging and finally loaded to fracture. Results There was a significant difference (P<0.05) between the core designs, but not between the different types of Y-TZP materials. The split-file designs with VITABLOCS® (1,806±165 N) and e.max® ZirPress (1,854±115 N) and the state-of-the-art design with VITA VM® 9 (1,849±150 N) demonstrated the highest mean fracture values. Conclusion The shape of a split-file designed all-ceramic reconstruction calls for a different dimension protocol, compared to traditionally shaped ones, as the split-file design leads to sharp approximal indentations acting as fractural impressions, thus decreasing the overall strength. The design of a framework is a crucial factor for the load bearing capacity of an all-ceramic FDP. The state-of-the-art design is preferable since the split-file designed cores call for a cross-sectional connector area at least 42% larger, to have the same load bearing capacity as the state-of-the-art designed cores. All veneering materials and techniques tested in the study, split-file, over-press, built-up porcelains, and glass–ceramics are, with a great safety margin, sufficient for clinical use

  20. Direct Composite Laminate Veneers: Three Case Reports

    PubMed Central

    Korkut, Bora; Yanıkoğlu, Funda; Günday, Mahir

    2013-01-01

    Re-establishing a patient’s lost dental esthetic appearance is one of the most important topics for contemporary dentistry. New treatment materials and methods have been coming on the scene, day by day, in order to achieve such an aim. Most dentists prefer more conservative and aesthetic approaches, such as direct and indirect laminate veneer restorations, instead of full-ceramic crowns for anteriors where aesthetics is really important. Laminate veneers are restorations which are envisioned to correct existing abnormalities, esthetic deficiencies and discolo-rations. Laminate veneer restorations may be processed in two different ways: direct or indirect. Direct laminate veneers have no need to be prepared in the laboratory and are based on the principle of application of a composite material directly to the prepared tooth surface in the dental clinic. Indirect laminate veneers may be produced from composite materials or ceramics, which are cemented to the tooth with an adhesive resin. In this case report, direct composite laminate veneer technique used for three patients with esthetic problems related to fractures, discolorations and an old prolapsed restoration, is described and six-month follow-ups are discussed. As a conclusion, direct laminate veneer restorations may be a treatment option for patients with the esthetic problems of anterior teeth in cases similar to those reported here. PMID:23875090

  1. Porcelain laminate veneers: Clinical survey for evaluation of failure

    PubMed Central

    Alhekeir, Diemah F.; Al-Sarhan, Rana A.; Al Mashaan, Abdulmohsen F.

    2014-01-01

    Objective To investigate the association of the failure of porcelain laminate veneers with factors related to the patient, material, and operator. Methods This clinical survey involved 29 patients (19 women and 10 men) and their dentists, including undergraduate and postgraduate dental students and dental interns. Two questionnaires were distributed to collect information from participants. All patients were clinically examined. Criteria for failure of the porcelain laminate veneers included color change, cracking, fracture, and/or debonding. Results A total of 205 porcelain laminate veneers were evaluated. All of the restorations were fabricated from IPS e.max Press and cemented with Variolink Veneer (Ivoclar Vivadent, Schaan, Principality of Liechtenstein) or RelyX veneer cement (3M ESPE, St. Paul, MN, USA). The preparations were generally located in enamel (58.6%), and most veneers had an overlapped design (89.7%). Ten patients (34.48%) showed veneer failure, most often in terms of color change (60%). Overall, 82.8% of patients were satisfied with their restorations. Conclusion Insufficient clinical skills or operator experience resulted in restoration failure in one-third of patients. PMID:25408598

  2. Shear Bond Strengths between Three Different Yttria-Stabilized Zirconia Dental Materials and Veneering Ceramic and Their Susceptibility to Autoclave Induced Low-Temperature Degradation

    PubMed Central

    Sehgal, Manoti; Bhargava, Akshay; Gupta, Sharad; Gupta, Prateek

    2016-01-01

    A study was undertaken to evaluate the effect of artificial aging through steam and thermal treatment as influencing the shear bond strength between three different commercially available zirconia core materials, namely, Upcera, Ziecon, and Cercon, layered with VITA VM9 veneering ceramic using Universal Testing Machine. The mode of failure between zirconia and ceramic was further analyzed as adhesive, cohesive, or mixed using stereomicroscope. X-ray diffraction and SEM (scanning electron microscope) analysis were done to estimate the phase transformation (m-phase fraction) and surface grain size of zirconia particles, respectively. The purpose of this study was to simulate the clinical environment by artificial aging through steam and thermal treatment so as the clinical function and nature of the bond between zirconia and veneering material as in a clinical trial of 15 years could be evaluated. PMID:27293439

  3. Shear Bond Strengths between Three Different Yttria-Stabilized Zirconia Dental Materials and Veneering Ceramic and Their Susceptibility to Autoclave Induced Low-Temperature Degradation.

    PubMed

    Sehgal, Manoti; Bhargava, Akshay; Gupta, Sharad; Gupta, Prateek

    2016-01-01

    A study was undertaken to evaluate the effect of artificial aging through steam and thermal treatment as influencing the shear bond strength between three different commercially available zirconia core materials, namely, Upcera, Ziecon, and Cercon, layered with VITA VM9 veneering ceramic using Universal Testing Machine. The mode of failure between zirconia and ceramic was further analyzed as adhesive, cohesive, or mixed using stereomicroscope. X-ray diffraction and SEM (scanning electron microscope) analysis were done to estimate the phase transformation (m-phase fraction) and surface grain size of zirconia particles, respectively. The purpose of this study was to simulate the clinical environment by artificial aging through steam and thermal treatment so as the clinical function and nature of the bond between zirconia and veneering material as in a clinical trial of 15 years could be evaluated.

  4. Damage maps of veneered zirconia under simulated mastication.

    PubMed

    Kim, J-W; Kim, J-H; Janal, M N; Zhang, Y

    2008-12-01

    Zirconia-based restorations often fracture from chipping and/or delamination of the porcelain veneers. We hypothesized that veneer chipping/delamination is a result of the propagation of near-contact-induced partial cone cracks on the occlusal surface under mastication. Masticatory loading involves the opposing tooth sliding along the cuspal inner incline surface with an applied biting force. To test this hypothesis, we cemented flat porcelain-veneered zirconia plates onto dental composites and cyclically loaded them (contact-slide-liftoff) at an inclination angle as a simplified model of zirconia-based restorations under occlusion. In light of in situ observation of damage evolution in a transparent glass/zirconia/polycarbonate trilayer, post mortem damage evaluation of porcelain/zirconia/composite trilayers by a sectioning technique revealed that deep-penetrating occlusal surface partial cone fracture is the predominant fracture mode of porcelain veneers. Clinical relevance is discussed.

  5. Joining veneers to ceramic cores and dentition with adhesive interlayers.

    PubMed

    Lee, J J-W; Wang, Y; Lloyd, I K; Lawn, B R

    2007-08-01

    Adhesive joining of veneers to cores offers potential simplicity and economy in the fabrication of all-ceramic crowns. We tested the hypothesis that resin-based adhesives can be used for such fabrication without compromising mechanical integrity of the crown structure. A simple test procedure for quantifying this hypothesis was proposed. A model glass veneer layer 1 mm thick (representative of porcelain), adhesively bonded onto a glass-like core substrate (ceramic or dental enamel), was loaded at its top surface with a hard sphere (occlusal force) until a radial crack initiated at the veneer undersurface. The critical loads for fracture, visually observable in the transparent glass, afforded a measure of the predisposition for the adhesive to cause veneer failure in an occlusal overload. Two adhesives were tested, one a commercial epoxy resin and the other a relatively stiff in-house-developed composite. The results confirmed that stiffer adhesives provide higher resistance to failure.

  6. Damage Maps of Veneered Zirconia under Simulated Mastication

    PubMed Central

    Kim, Jae-Won; Kim, Joo-Hyung; Janal, Malvin N.; Zhang, Yu

    2016-01-01

    Zirconia based restorations often fracture from chipping and/or delamination of the porcelain veneers. We hypothesize that veneer chipping/delamination is a result of the propagation of near-contact induced partial cone cracks on the occlusal surface under mastication. Masticatory loading involves the opposing tooth sliding along the cuspal inner incline surface with an applied biting force. To test this hypothesis, flat porcelain veneered zirconia plates were cemented to dental composites and cyclically loaded (contact–slide–liftoff) at an inclination angle as a simplified model of zirconia based restorations under occlusion. In the light of in-situ observation of damage evolution in a transparent glass/zirconia/polycarbonate trilayer, postmortem damage evaluation of porcelain/zirconia/composite trilayers using a sectioning technique revealed that deep penetrating occlusal surface partial cone fracture is the predominant fracture mode of porcelain veneers. Clinical relevance is discussed. PMID:19029080

  7. Esthetic rehabilitation with laminated ceramic veneers reinforced by lithium disilicate.

    PubMed

    Soares, Paulo Vinícius; Spini, Pedro Henrique Rezende; Spini, Pedro Henrique; Carvalho, Valessa Florindo; Souza, Paula Gomes; Gonzaga, Ramon Corrêa de Queiroz; Gonzaga, Ramon Corrêa; Tolentino, Andrea Barros; Machado, Alexandre Coelho

    2014-02-01

    Because of their predictable results and conservation of tooth structure, ceramic veneers are indicated for the esthetic treatment of anterior teeth with anomalous positions or appearance. The objective of this case report is to highlight the steps in dental rehabilitation using ceramic veneers reinforced by lithium disilicate. In this case the patient had diastemas between the mandibular incisors. After preliminary procedures, diagnostic models, waxing, and mock-up were completed, an impression was made with addition silicone, and the veneers were fabricated and cemented with light-cure cement. As a result, the esthetics and function expected by the patient were achieved. The use of ceramic veneers enabled a conservative and esthetically successful rehabilitation treatment.

  8. Fabrication of lithium silicate ceramic veneers with a CAD/CAM approach: a clinical report of cleidocranial dysplasia.

    PubMed

    da Cunha, Leonardo Fernandes; Mukai, Eduardo; Hamerschmitt, Raphael Meneghetti; Correr, Gisele Maria

    2015-05-01

    The fabrication of minimally invasive ceramic veneers remains a challenge for dental restorations involving computer-aided design and computer-aided manufacturing (CAD/CAM). The application of an appropriate CAD/CAM protocol and correlation mode not only simplifies the fabrication of ceramic veneers but also improves the resulting esthetics. Ceramic veneers can restore tooth abnormalities caused by disorders such as cleidocranial dysplasia, enamel hypoplasia, or supernumerary teeth. This report illustrates the fabrication of dental veneers with a new lithium silicate ceramic and the CAD/CAM technique in a patient with cleidocranial dysplasia.

  9. Chairside veneering of composite resin to anterior stainless steel crowns: another look.

    PubMed

    Wiedenfeld, K R; Draughn, R A; Goltra, S E

    1995-01-01

    The chairside veneering of stainless steel crowns using the technique described in our original article (J Dent Child, 61: 321-326 September-December 1994) has proven to be a very dependable and successful technique for restoring severely damaged primary anterior teeth. In this article an advancement in the technique is described using new light-cured materials that simplify the veneering process and produce thinner veneers. The resulting veneers maintain the adaptability, strength, and gingival contour benefits of the stainless steel crown in conjunction with the cosmetics of composite facings. The chairside technique can be quickly mastered by a dental auxiliary and results in veneered crowns with very high shear and bond strengths.

  10. Esthetic, occlusal, and periodontal rehabilitation of anterior teeth with minimum thickness porcelain laminate veneers.

    PubMed

    da Cunha, Leonardo Fernandes; Pedroche, Lorena Oliveira; Gonzaga, Carla Castiglia; Furuse, Adilson Yoshio

    2014-12-01

    Ceramic veneers of minimum thickness provide satisfactory esthetic outcomes while preserving the dental structure. Dental ceramics can both improve the esthetic appearance and reestablish the strength and function of teeth. In worn anterior teeth, functional surfaces, for example, anterior and lateral guidance, can be restored effectively. The characteristics of dental ceramics, such as color stability and mechanical and optical properties, make this material a good choice for indirect restorations, especially when optimum function and esthetics are required. This clinical report presents an occlusal, periodontal, and restorative solution with minimum thickness glass ceramic veneers for worn anterior teeth with multiple diastemas.

  11. Fracture mechanics analyses of ceramic/veneer interface under mixed-mode loading.

    PubMed

    Wang, Gaoqi; Zhang, Song; Bian, Cuirong; Kong, Hui

    2014-11-01

    Few studies have focused on the interface fracture performance of zirconia/veneer bilayered structure, which plays an important role in dental all-ceramic restorations. The purpose of this study was to evaluate the fracture mechanics performance of zirconia/veneer interface in a wide range of mode-mixities (at phase angles ranging from 0° to 90°), and to examine the effect of mechanical properties of the materials and the interface on the fracture initiation and crack path of an interfacial crack. A modified sandwich test configuration with an oblique interfacial crack was proposed and calibrated to choose the appropriate geometry dimensions by means of finite element analysis. The specimens with different interface inclination angles were tested to failure under three-point bending configuration. Interface fracture parameters were obtained with finite element analyses. Based on the interfacial fracture mechanics, three fracture criteria for crack kinking were used to predict crack initiation and propagation. In addition, the effects of residual stresses due to coefficient of thermal expansion mismatch between zirconia and veneer on the crack behavior were evaluated. The crack initiation and propagation were well predicted by the three fracture criteria. For specimens at phase angle of 0, the cracks propagated in the interface; whereas for all the other specimens the cracks kinked into the veneer. Compressive residual stresses in the veneer can improve the toughness of the interface structure. The results suggest that, in zirconia/veneer bilayered structure the veneer is weaker than the interface, which can be used to explain the clinical phenomenon that veneer chipping rate is larger than interface delamination rate. Consequently, a veneer material with larger fracture toughness is needed to decrease the failure rate of all-ceramic restorations. And the coefficient of thermal expansion mismatch of the substrates can be larger to produce larger compressive

  12. Esthetic and functional rehabilitation of crowded mandibular anterior teeth using ceramic veneers: a case report.

    PubMed

    de Andrade, Oswaldo Scopin; Ferreira, Luiz Alves; Hirata, Ronaldo; Rodrigues, Flavia Pires; D'Alpino, Paulo Henrique Perlatti; Di Hipolito, Vinicius

    2012-09-01

    The use of ceramic veneers to restore crowded teeth in the maxilla has been widely discussed in the literature. However, the use of this technique in the mandible has received little attention. Therefore, this case report describes the treatment of crowded mandibular anterior teeth using ceramic veneers. The primary treatment challenge in this region is the reduced tooth structure available for rehabilitation. Proper communication between the clinician and dental technician is required to achieve clinical success. This article presents a straightforward treatment plan and restorative technique that includes both the clinical and laboratory sequences necessary for predictable and stable postoperative outcomes.

  13. Evaluation of shear bond strength between zirconia core and ceramic veneers fabricated by pressing and layering techniques: In vitro study

    PubMed Central

    Subash, M.; Vijitha, D.; Deb, Saikat; Satish, A.; Mahendirakumar, N.

    2015-01-01

    Statement of Problem: Although ceramic veneered on to zirconia core have been in use for quite some time, information regarding the comparative evaluation of the Shear bond strength of Pressable & Layered ceramic veneered on to zirconia core is limited. Purpose of study: To evaluate the shear bond strength of zirconia core and ceramic veneer fabricated by two different techniques, Layering (Noritake CZR) and Pressing (Noritake, CZR Press). Materials and Method: 20 samples of zirconia blocks were fabricated and the samples were divided into group A & B. Group A - Ceramic Veneered over zirconia core by pressing using Noritake CZR Press. Group B - Ceramic Veneered over zirconia core by layering using Noritake CZR. The veneered specimens were mounted on to the center of a PVC tube using self-cure acrylic resin leaving 3 mm of the veneered surface exposed as cantilever. Using a Universal testing machine the blocks were loaded up to failure. Result: The results were tabulated by using independent samples t-test. The mean shear bond strength for Pressed specimens was 12.458 ± 1.63(S.D) MPa and for layered specimens was 8.458 ± 0.845(S.D) MPa. Conclusion: Pressed specimens performed significantly better than the layered specimen with a P value 0.001. Clinicians and dental laboratory technicians should consider the use of pressed ceramics as an alternative to traditional layering procedures to reduce the chances of chipping or de-lamination of ceramics PMID:26538929

  14. Retention of esthetic veneers on primary stainless steel crowns.

    PubMed

    Baker, L H; Moon, P; Mourino, A P

    1996-01-01

    The purpose of this study was to ascertain the amount of shearing force necessary to fracture, dislodge or deform the esthetic veneer facings of four commercially available veneered primary incisor stainless steel crowns. The four types tested were: Cheng Crowns, [Peter Cheng Orthodontic Laboratory]; Whiter Biter Crown II, [White Bite Inc.]; Kinder Krowns, [Mayclin Dental Studio, Inc]; and NuSmile Primary Crowns, [Orthodontic Technologies, Inc]. The crowns (#4 right central incisor) from each manufacturer were obtained with the facings attached. The crowns were soaked for ninety days and thermocycled at 4 degrees C and 55 degrees C for 500 45-second cycles. The crowns were cemented to standardized chromium cobalt metal dies. Each die was placed in to a custom holder on the Instron Universal testing machine. A force was applied at the incisal edge of the veneer at 148 degrees, (the primary interincisal angle), with a crosshead speed of 0.05 inches/minute until the veneer either fractured, dislodged or deformed. The mean force (Ibs) required +/- SD to produce failure, in descending order, was as follows: Cheng (107.8 +/- 17.3); NuSmile (100.2 +/- 18.2); KinderKrown (91.3 +/- 27.4)d Whiter Biter (81.5 +/- 21.7). To test the hypothesis of no difference among the four manufacturers, an analysis of variance was performed using PROC GLM. The resultant F statistic was 2.79 (p < 0.0543), indicating a marginally statistically significant difference in the response variable "pressure" among the four groups. A posthoc test was then performed to ascertain where these differences occurred. These results, using Turkey's studentized range test for pairwise comparisons, suggested that the only difference was between the Cheng and Whiter Biter manufacturers.

  15. Evidence of yttrium silicate inclusions in YSZ-porcelain veneers.

    PubMed

    Stoner, Brian R; Griggs, Jason A; Neidigh, John; Piascik, Jeffrey R

    2014-04-01

    This report introduces the discovery of crystalline defects that can form in the porcelain veneering layer when in contact with yttria-stabilized zirconia (YSZ). The focus was on dental prostheses and understanding the defects that form in the YSZ/porcelain system; however the data reported herein may have broader implications toward the use and stability of YSZ-based ceramics in general. Specimens were cut from fully sintered YSZ plates and veneering porcelain was applied (<1 mm thick) to one surface and fired under manufacturer's recommended protocol. Scanning electron microscopy (SEM) with integrated electron dispersive X-ray (EDAX) was used for microstructural and elemental analysis. EDAX, for chemical analysis and transmission electron diffraction (TED) for structural analysis were both performed in the transmission electron microscope (TEM). Additionally, in order to spatially resolve Y-rich precipitates, micro-CT scans were conducted at varying depths within the porcelain veneer. Local EDAX (SEM) was performed in the regions of visible inclusions and showed significant increases in yttrium concentration. TEM specimens also showed apparent inclusions in the porcelain and selected area electron diffraction was performed on these regions and found the inclusions to be crystalline and identified as either yttrium-silicate (Y2 SiO5 ) or yttrium-disilicate (Y2 Si2 O7 ). Micro-CT data showed that yttrium-silicate precipitates were distributed throughout the thickness of the porcelain veneer. Future studies are needed to determine whether many of the premature failures associated with this materials system may be the result of crystalline flaws that form as a result of high temperature yttrium diffusion near the surfaces of YSZ.

  16. Minimally Invasive Laminate Veneers: Clinical Aspects in Treatment Planning and Cementation Procedures

    PubMed Central

    Morita, R. K.; Hayashida, M. F.; Berger, G.; Reggiani, R. D.; Betiol, E. A. G.

    2016-01-01

    When a definitive aesthetic treatment is determined, it is crucial to grant the patient's wish with the necessary dental treatment. Thus, conservative treatments that are the solution to aesthetic problems involving morphologic modifications and provide the result that the patient expects should always be the first therapeutic option. In this context, ceramic laminate veneers, also known as “contact lens,” are capable of providing an extremely faithful reproduction of the natural teeth with great color stability and periodontal biocompatibility. Minimal or no preparation veneers are heavily advertised as the answer to our patients' cosmetic needs, which they can be if they are used correctly in the appropriate case. This report is about ultraconservative restorations to achieve functional and aesthetic rehabilitation through treatment planning. Thus, clinicians should be aware that the preparation for laminate veneers remains within enamel, to ensure the bond strength and avoid or minimize the occurrence of postoperative sensitivity. PMID:28070427

  17. Investigation on the Tribological Behavior and Wear Mechanism of Five Different Veneering Porcelains

    PubMed Central

    Min, Jie; Zhang, Qianqian; Qiu, Xiaoli; Zhu, Minhao; Yu, Haiyang; Gao, Shanshan

    2015-01-01

    Objectives The primary aim of this research was to investigate the wear behavior and wear mechanism of five different veneering porcelains. Methods Five kinds of veneering porcelains were selected in this research. The surface microhardness of all the samples was measured with a microhardness tester. Wear tests were performed on a ball-on-flat PLINT fretting wear machine, with lubrication of artificial saliva at 37°C. The friction coefficients were recorded by the testing system. The microstructure features, wear volume, and damage morphologies were recorded and analyzed with a confocal laser scanning microscope and a scanning electron microscope. The wear mechanism was then elucidated. Results The friction coefficients of the five veneering porcelains differ significantly. No significant correlation between hardness and wear volume was found for these veneering porcelains. Under lubrication of artificial saliva, the porcelain with higher leucite crystal content exhibited greater wear resistance. Additionally, leucite crystal size and distribution in glass matrix influenced wear behavior. The wear mechanisms for these porcelains were similar: abrasive wear dominates the early stage, whereas delamination was the main damage mode at the later stage. Furthermore, delamination was more prominent for porcelains with larger crystal sizes. Significance Wear compatibility between porcelain and natural teeth is important for dental restorative materials. Investigation on crystal content, size, and distribution in glass matrix can provide insight for the selection of dental porcelains in clinical settings. PMID:26368532

  18. Esthetic Rehabilitation of the Smile with No-Prep Porcelain Laminates and Partial Veneers

    PubMed Central

    Farias-Neto, Arcelino; Gomes, Edna Maria da Cunha Ferreira; Sánchez-Ayala, Alfonso; Sánchez-Ayala, Alejandro; Vilanova, Larissa Soares Reis

    2015-01-01

    Rehabilitation of patients with anterior conoid teeth may present a challenge for the clinician, especially when trying to mimic the nature with composite resins. This clinical report exemplifies how a patient with conoid upper lateral incisors was rehabilitated with minimally invasive adhesive restorations. Following diagnostic wax-up and cosmetic mock-up, no-prep veneers and ceramic fragments (partial veneers) were constructed with feldspathic porcelain. This restorative material presents excellent reproduction of the optical properties of the dental structure, especially at minimal thicknesses. In this paper, the details about the treatment are described. A very pleasing outcome was achieved, confirming that minimally invasive adhesive restorations are an excellent option for situations in which the dental elements are healthy, and can be modified exclusively by adding material and the patient does not want to suffer any wear on the teeth. PMID:26568893

  19. Esthetic Rehabilitation through Crown Lengthening Surgery and Conservative CAD/CAM Veneers: A Multidisciplinary Case Report

    PubMed Central

    Soares, Fernando Peixoto; Gallo, Mauricio

    2016-01-01

    This case report describes a successful multidisciplinary approach used to improve the smile esthetics of a patient presenting with excessive gingival display, asymmetric gingival margins, and small upper anterior teeth and lower anterior teeth. The treatment combined esthetic crown lengthening, dental bleaching, and restorative dentistry using CAD/CAM veneer. The 6-month follow-up examination confirmed the stability of the modification and absence of adverse effects. PMID:27668099

  20. Human enamel veneer restoration: an alternative technique to restore anterior primary teeth.

    PubMed

    Oliveira, Luciana Butini; Tamay, Tereza Keiko; Oliveira, Marta Dutra Machado; Rodrigues, Célia Martins Delgado; Wanderley, Marcia Turolla

    2006-01-01

    Restoration of severely decayed primary teeth is a clinical challenge in Pediatric Dentistry. Among the restorative treatment options, the use of prefabricated crowns and resin composite restorations, either by means of direct or indirect techniques is mentioned in the literature. The purpose of this article is to describe the rehabilitation of primary anterior teeth in a 5-year-old patient. Dental treatment consisted on an anterior space maintainer prosthesis made with natural primary teeth, plus human dental enamel veneer (facet) restorations. The advantages of this technique are better esthetics and the natural enamel has physiologic wear and offers superficial smoothness and cervical adaptation compatible with those of the surrounding teeth.

  1. Ceramics as biomaterials for dental restoration.

    PubMed

    Höland, Wolfram; Schweiger, Marcel; Watzke, Ronny; Peschke, Arnd; Kappert, Heinrich

    2008-11-01

    Sintered ceramics and glass-ceramics are widely used as biomaterials for dental restoration, especially as dental inlays, onlays, veneers, crowns or bridges. Biomaterials were developed either to veneer metal frameworks or to produce metal-free dental restorations. Different types of glass-ceramics and ceramics are available and necessary today to fulfill customers' needs (patients, dentists and dental technicians) regarding the properties of the biomaterials and the processing of the products. All of these different types of biomaterials already cover the entire range of indications of dental restorations. Today, patients are increasingly interested in metal-free restoration. Glass-ceramics are particularly suitable for fabricating inlays, crowns and small bridges, as these materials achieve very strong, esthetic results. High-strength ceramics are preferred in situations where the material is exposed to high masticatory forces.

  2. Rehabilitation of a patient with amelogenesis imperfecta using porcelain veneers and CAD/CAM polymer restorations: A clinical report.

    PubMed

    Saeidi Pour, Reza; Edelhoff, Daniel; Prandtner, Otto; Liebermann, Anja

    2015-01-01

    The complete dental rehabilitation of patients with a vertical dimension loss (VDL) caused by structural enamel deficits associated with amelogenesis imperfecta (AI) represents a difficult challenge for restorative teams. Accurate analysis and treatment planning that includes esthetic and functional evaluations and adequate material selection are important prerequisites for successful results. Long-term provisional restorations play an important role in exploring and elucidating the patients' esthetic demands and functional needs. Restorative treatment options can vary from requiring only oral hygiene instructions to extensive dental restorations that include composite fillings, ceramic veneers, metal-ceramic, or all-ceramic crowns. This case report describes a full-mouth rehabilitation of a patient with amelogenesis imperfecta including the case planning, bite replacement, preparation, and restoration setting steps with an experimental CAD/CAM polymer and porcelain veneers.

  3. 40 CFR 63.2266 - Initial compliance demonstration for a veneer redryer.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... operate a veneer redryer, you must record the inlet moisture content of the veneer processed in the... inlet veneer moisture content with your Notification of Compliance Status to show that your veneer redryer processes veneer with an inlet moisture content of less than or equal to 25 percent (by...

  4. 40 CFR 63.2266 - Initial compliance demonstration for a veneer redryer.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    .... If you operate a veneer redryer, you must record the inlet moisture content of the veneer processed... average inlet veneer moisture content with your Notification of Compliance Status to show that your veneer redryer processes veneer with an inlet moisture content of less than or equal to 25 percent (by...

  5. Er:YAG laser debonding of porcelain veneers

    NASA Astrophysics Data System (ADS)

    Buu, Natalie; Morford, Cynthia; Finzen, Frederick; Sharma, Arun; Rechmann, Peter

    2010-02-01

    The removal of porcelain veneers using Er:YAG lasers has not been previously described in the scientific literature. This study was designed to systematically investigate the efficacy of an Er:YAG laser on veneer debonding without damaging the underlying tooth structure, as well as preserving a new or misplaced veneer. Initially, Fourier Transform Infrared Spectroscopy (FTIR) was used on flat porcelain veneer samples (IPS Empress Esthetic; Ivoclar Vivadent, Amherst, NY) to assess which infrared laser wavelengths are transmitted through the veneer. Additionally, FTIR spectra from a veneer bonding cement (RelyX Veneer Cement A1; 3M ESPE, St. Paul, MN) were obtained. While the veneer material showed no characteristic water absorption bands in the FTIR, the bonding cement has a broad H2O/OH absorption band coinciding with the ER:YAG laser emission wavelength. Consequently Er:YAG laser energy transmission through different veneer thicknesses was measured. The porcelain veneers transmitted 11 - 18 % of the incident Er:YAG laser energy depending on their thicknesses (Er:YAG laser: LiteTouch by Syneron; wavelength 2,940 nm, 10 Hz repetition rate, pulse duration 100 μs at 133 mJ/pulse; straight sapphire tip 1,100 μm diameter; Syneron, Yokneam, Israel). Initial signs of cement ablation occurred at approximately 1.8 - 4.0 J/cm2. This can be achieved by irradiating through the veneer with the fiber tip positioned at a distance of 3-6 mm from the veneer surface, and operating the Er:YAG laser with 133 mJ output energy. All eleven veneers bonded on extracted anterior incisor teeth were easily removed using the Er:YAG laser. The removal occurred without damaging underlying tooth structure as verified by light microscopic investigation (Incident Light Microscope Olympus B 50, Micropublisher RTV 3.3 MP, Image Pro software, Olympus). The debonding mainly occurred at the cement/veneer interface. When the samples were stored in saline solution for 5 days and/or an air-waterspray was

  6. The efficiency of different light sources to polymerize resin cement beneath porcelain laminate veneers.

    PubMed

    Usumez, A; Ozturk, A N; Usumez, S; Ozturk, B

    2004-02-01

    Plasma arc light units for curing resin composites have been introduced with the claim of relatively short curing times. The purpose of this study was to evaluate the efficiency of two different light sources to polymerize dual curing resin cement beneath porcelain laminate veneers. Twenty extracted healthy human maxillary centrals were used. Teeth were sectioned 2 mm below the cemento-enamel junction and crown parts were embedded into self-cure acrylic resin, labial surface facing up. Cavity preparation was carried out on labial surfaces. These teeth were divided into two groups of 10 each. The resin cement/veneer combination was exposed to two different photo polymerization units. A conventional halogen light (Hilux 350, Express Dental Products) and a plasma arc light (Power PAC, ADT) were used to polymerize resin cement. Ten specimens were polymerized conventionally (40 s) and the other specimens by plasma arc curing (PAC) (6 s). Two samples from each tooth measuring 1.2 x 1.2 x 5 mm were prepared. These sections were subjected to microshear testing and failure values were recorded. Statistically significant differences were found between the bond strength of veneers exposed to conventional light and PAC unit (P < 0.001). Samples polymerized with halogen light showed better bond strength. The results of this study suggest that the curing efficiency of PAC through ceramic was lower compared with conventional polymerization for the exposure durations tested in this study.

  7. Minimally invasive veneers: current state of the art

    PubMed Central

    Vanlıoğlu, Burçin Akoğlu; Kulak-Özkan, Yasemin

    2014-01-01

    Ceramic veneers are considered a conservative solution for patients requiring improvement of the shape, color, or position of their anterior teeth. Ceramic veneers have been extensively and successfully used to mask intrinsic staining, to give the appearance of straightening, and to correct minor malformations of anterior teeth without the removal of substantial amounts of sound tooth substance. The current literature was reviewed to search for the most important parameters determining the long-term success and correct application of ceramic veneers. PMID:25506248

  8. Shear bond strength of veneering porcelain to porous zirconia.

    PubMed

    Nakamura, Takashi; Sugano, Tsuyoshi; Usami, Hirofumi; Wakabayashi, Kazumichi; Ohnishi, Hiroshi; Sekino, Tohru; Yatani, Hirofumi

    2014-01-01

    In this study, two types of porous zirconia and dense zirconia were used. The flexural strength of non-layered zirconia specimens and those of the layered zirconia specimens with veneering porcelain were examined. Furthermore, the shear bond strength of veneering porcelain to zirconia was examined. The flexural strength of the non-layered specimens was 1,220 MPa for dense zirconia and 220 to 306 MPa for porous zirconia. The flexural strength of the layered specimens was 360 MPa for dense zirconia and 132 to 156 MPa for porous zirconia, when a load was applied to the porcelain side. The shear bond strength of porcelain veneered to dense zirconia was 27.4 MPa and that of porcelain veneered to porous zirconia was 33.6 to 35.1 MPa. This suggests that the veneering porcelain bonded strongly to porous zirconia although porous zirconia has a lower flexural strength than dense zirconia.

  9. Stress distribution in bone: single-unit implant prostheses veneered with porcelain or a new composite material.

    PubMed

    Juodzbalys, Gintaras; Kubilius, Ricardas; Eidukynas, Valdas; Raustia, Aune M

    2005-06-01

    The purpose of this study was to simulate dynamic and static occlusal loading on one unit fixed, implant-supported prostheses veneered with porcelain and with GRADIA in a 3-dimensional finite element model of the human mandible to analyze and compare the resultant stresses in the superstructures and in the supporting bone. Calculation and visualization of stress, deformation, and displacement of complex structures under simulated forces were evaluated by finite element analysis (FEA) using ANSYS. The device employed was from the OSTEOFIX Dental Implant System (Oulu, Finland), and the veneering materials used were standard dental porcelain and GC GRADIA (Tokyo, Japan), a new composite material. Two different loading conditions were considered: static and transitional or impact, each delivered in three different directions: horizontal (Fh) at 0 degrees , vertical (Fv) at 90 degrees , and oblique (Fo) at 120 degrees . The proportion of the force: magnitude was fh:fv:fo = 1:3.5:7. A vertical load of 500 N, a horizontal load of 143 N, and an oblique load of 1000 N were applied. The results showed that the highest stresses in the bone-implant interface occurred in the region of cortical bone adjacent to the first thread of implants in all models and varied within 6.5%. Maximum stresses and displacements were higher (7%) in those models with statically loaded implants as compared with those that had been dynamically loading. The direction of loading played a major role in determining stress levels and they varied at up to 85%. It was shown that with dynamic loads, the peak of 1.568 mm was registered in the model with the GRADIA veneering material. This displacement was 6.5% higher than that found with the Vita VMK 68 veneers. These results suggest that the implant superstructure-fixed single crown veneering materials-porcelain and GRADIA played minor influences to the displacements and stresses in the implant supported bone with a 1% variance. One of the reasons for this

  10. Porcelain veneering of titanium--clinical and technical aspects.

    PubMed

    Haag, Per

    2011-01-01

    Gold and other alloys have long been used for the production of crowns and bridges as replacements for damaged or lost teeth. However, doubts have arisen on the suitability of using these materials for dental restorations, as gold has also shown a capacity to cause side-effects such as allergic reactions. This is especially valid for alloys, which during the last decades have been used as porcelain-fused-to metal restorations. This fact has led to an interest in using titanium instead of these alloys. Trials to use titanium for this purpose were initiated in Japan in the early 1980s. Titanium as an unalloyed metal differs in two aspects from the above named alloys: it has a phase transformation at 882 degrees C, which changes its outer and inner properties, and it has an expansion that lies between that of the porcelain types available on the market at the time. In Japan a technique for casting titanium was developed, where the after-treatment of the casting was elaborate, to re-establish the original properties of titanium. The porcelain developed for veneering had shortcomings as the rendering produced a rough surface and non satisfactory esthetics. In Sweden a new concept was introduced in 1989. Here the processing of titanium was performed by industrial methods such as milling, spark erosion and laser welding. The idea behind this was to avoid phase transformation. During the 1990s a number of porcelain products were launched and a vast number of both laboratory and clinical studies were performed and published, with varying results. In the first study of this thesis a prospective clinical trial was performed at a public dental health clinic in Sweden. Twenty-five patients were provided with 40 copings of pure titanium, which were veneered with porcelain. After 2 years 36 of these crowns were evaluated and the patients were also interviewed regarding problems such as shooting pains or difficulties in cleaning around the teeth that were crowned. This evaluation

  11. Biaxial flexural strength of bilayered zirconia using various veneering ceramics

    PubMed Central

    Chantranikul, Natravee

    2015-01-01

    PURPOSE The aim of this study was to evaluate the biaxial flexural strength (BFS) of one zirconia-based ceramic used with various veneering ceramics. MATERIALS AND METHODS Zirconia core material (Katana) and five veneering ceramics (Cerabien ZR; CZR, Lava Ceram; LV, Cercon Ceram Kiss; CC, IPS e.max Ceram; EM and VITA VM9; VT) were selected. Using the powder/liquid layering technique, bilayered disk specimens (diameter: 12.50 mm, thickness: 1.50 mm) were prepared to follow ISO standard 6872:2008 into five groups according to veneering ceramics as follows; Katana zirconia veneering with CZR (K/CZR), Katana zirconia veneering with LV (K/LV), Katana zirconia veneering with CC (K/CC), Katana zirconia veneering with EM (K/EM) and Katana zirconia veneering with VT (K/VT). After 20,000 thermocycling, load tests were conducted using a universal testing machine (Instron). The BFS were calculated and analyzed with one-way ANOVA and Tukey HSD (α=0.05). The Weibull analysis was performed for reliability of strength. The mode of fracture and fractured surface were observed by SEM. RESULTS It showed that K/CC had significantly the highest BFS, followed by K/LV. BFS of K/CZR, K/EM and K/VT were not significantly different from each other, but were significantly lower than the other two groups. Weibull distribution reported the same trend of reliability as the BFS results. CONCLUSION From the result of this study, the BFS of the bilayered zirconia/veneer composite did not only depend on the Young's modulus value of the materials. Further studies regarding interfacial strength and sintering factors are necessary to achieve the optimal strength. PMID:26576251

  12. Aesthetic Management of Fluoresced Teeth with Ceramic Veneers and Direct Composite Bonding – An Overview and A Case Presentation

    PubMed Central

    Jhajharia, Kapil; Shah, Harsh Haren; Paliwal, Ashutosh; Parikh, Viral

    2015-01-01

    Tooth discolouration is a common problem and affects people of all ages. Apart from the conventional treatment modalities for the same, newer options are available today with better techniques and materials. The present case report describes a 17-year-old girl who had stained and pitted teeth, attributable to dental fluorosis and she desired aesthetic treatment for the same. The pros and cons of all treatment options were carefully weighed and a multistep treatment process involving ceramic veneers and direct bonding were planned. The execution of the planned treatment yielded a good aesthetic and functional outcome. PMID:26266231

  13. Mandibular ceramic veneers: an examination of complex cases.

    PubMed

    Nixon, R L

    1995-05-01

    The indications for mandibular anterior ceramic veneers, tooth preparation design, provisionalization considerations, and placement procedures were presented in a previous article by the author. The functional utility, tissue biocompatibility, and dissimilarities of mandibular veneers, in comparison to maxillary anterior ceramic veneers, were explored, along with indications and contraindications for this form of treatment. This article demonstrates the aesthetic range of these restorations in the context of more complex cases. The learning objective of this article is to illustrate the viability of mandibular ceramic veneers in realigning teeth nonorthodontically, while sustaining the biologic health of the periodontium, stability of the occlusion, and aesthetic parameters of each case. The importance of wax mock-ups is outlined for visualization of the final result, as well as the evaluation of root proximity to avoid subgingival ledging of the teeth and subsequent periodontal disease. Orthodontics and other methods for the correction of anterior crowding are discussed.

  14. Photodegradation of heat treated hardwood veneers.

    PubMed

    Denes, Levente; Lang, Elemer M

    2013-01-05

    This paper outlines an investigation pertaining to color changes of hardwood veneers exposed to elevated temperature. The effects of convection and contact type heat applications on the different species were separately evaluated. The experimental analyses included two-factor, three-level randomized block designs, where the factors were the temperature and the duration of the exposure. Examined species included: Yellow-poplar (Liriodendron tulipifera L.) and red oak (Quercus rubra L.). Two way analysis of variance (ANOVA) indicated major overall effects with significant interactions between the factors for all species/heat-treatment combinations. However, pair wise comparisons (Tukey tests) revealed lack of significant differences within factors for certain levels. The gained information might be useful for adjusting drying or pressing time/temperature relations. Setting the desired colors by necessary processing operations has certain technological, economical and environmental advantages. The use of additional chemicals to create dark surfaces may be reduced or eliminated.

  15. Review on antibacterial biocomposites of structural laminated veneer lumber

    PubMed Central

    Chen, Zi-xiang; Lei, Qiong; He, Rui-lin; Zhang, Zhong-feng; Chowdhury, Ahmed Jalal Khan

    2015-01-01

    In this review, the characteristics and applications of structural laminated veneer lumber made from planted forest wood is introduced, and its preparation is explained, including various tree species and slab qualities, treatments for multiple effects and reinforced composites. The relevant factors in the bonding technology and pressing processes as well as the mechanical properties, research direction and application prospects of structural laminated veneer lumber made from planted forest wood are discussed. PMID:26858559

  16. Clinical Evaluation of Dental Restorative Materials

    DTIC Science & Technology

    1988-08-01

    of Nonprecious Alloys for Use with Porcelain Veneers . Part One, Physical Properties, J. Prosth Dent, 30: 424-431, 1973. Page 13...manufacturer (Jelenko and Company, Armonk, New York) recommends the use of their "thermotrol" casting set up. Attempt to cast this alloy with this piece of ...Nielsen, J.P. and Tuccillo, J’.J.: Calculations of Interfacial Stress in Dental Porcelain Bonded to Gold Alloy Substrate

  17. Effect of Ceramic Thickness and Luting Agent Shade on the Color Masking Ability of Laminate Veneers.

    PubMed

    Begum, Zubeda; Chheda, Pratik; Shruthi, C S; Sonika, Radhika

    2014-12-01

    The main objective of the study was to recognize the effect of ceramic thickness and luting agent on the extent to which the restoration masks color variations that may be present in the underlying dental structure. Two pressable ceramics were used: Lithium disilicate reinforced (IPS e.max- Ivoclar Vivadent) and Leucite reinforced (Cergo- Dentsply). Fifteen ceramic discs were manufactured from each ceramic and divided into three groups, according to the thickness (0.5, 1, 1.5 mm). To simulate the color of a dark underlying dental structure, background discs, color C3, with 20 mm diameter, were made using resin composite. The ceramic discs with varying thicknesses were seated on the dark background of the resin composite with either resinous opaque cement or resinous cement. The color parameters were determined by the CIE Lab system of colors using a spectrophotometer and color differences (ΔE) were calculated. The results were then statistically analyzed, using ANOVA test and Tukey HSD test. The ΔE values of both ceramic systems were affected by both the luting agent and the ceramic thickness (P < 0.05). The use of an opaque luting agent resulted in an increase of the ΔE* values for all ceramics tested, regardless of the thickness. For the 1.5-mm thick veneers, higher values in the color parameters were obtained for both ceramic materials. The color masking ability of ceramics used for laminate veneers is significantly affected by the thickness of the ceramic and the shade of the luting agent used.

  18. 46 CFR 32.56-50 - Combustible veneers-T/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... veneers on bulkheads, linings, and ceilings within accommodation, service, or control spaces must be 2 millimeters (.079 inches) or less in thickness. (b) Veneers on bulkheads, linings, and ceilings in...

  19. Dental Amalgam

    MedlinePlus

    ... 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 ...

  20. In vitro chipping behaviour of all-ceramic crowns with a zirconia framework and feldspathic veneering: comparison of CAD/CAM-produced veneer with manually layered veneer.

    PubMed

    Schmitter, M; Mueller, D; Rues, S

    2013-07-01

    The purpose of this in vitro study was to assess the breaking load of zirconia-based crowns veneered with either CAD/CAM-produced or manually layered feldspathic ceramic. Thirty-two identical zirconia frameworks (Sirona inCoris ZI, mono L F1), 0·6 mm thick with an anatomically shaped occlusal area, were constructed (Sirona inLab 3.80). Sixteen of the crowns were then veneered by the use of CAD/CAM-fabricated feldspathic ceramic (CEREC Bloc, Sirona) and 16 by the use of hand-layered ceramic. The CAD/CAM-manufactured veneer was attached to the frameworks by the use of Panavia 2.0 (Kuraray). Half of the specimens were loaded until failure without artificial ageing; the other half of the specimens underwent thermal cycling and cyclic loading (1·2 million chewing cycles, force magnitude F(max) = 108 N) before the assessment of the ultimate load. To investigate the new technique further, finite element (FE) computations were conducted on the basis of the original geometry. Statistical assessment was made by the use of non-parametric tests. Initial breaking load was significantly higher in the hand-layered group than in the CAD/CAM group (mean: 1165·86 N versus 395·45 N). During chewing simulation, however, 87·5% (7/8) of the crowns in the hand-layered group failed, whereas no crown in the CAD/CAM group failed. The CAD/CAM-produced veneer was significantly less sensitive to ageing than the hand-layered veneer.

  1. Endo-restorative treatment of a severly discolored upper incisor: resolution of the “aesthetic” problem through Componeer veneering System

    PubMed Central

    Migliau, Guido; Besharat, Laith Konstantinos; Sofan, Afrah Ali Abdullah; Sofan, Eshrak Ali Abdullah; Romeo, Umberto

    2015-01-01

    Summary Aim Re-establishing a patient’s lost dental aesthetic appearance is one of the most important topics for contemporary dentistry. New treatment materials and methods have been coming on the scene, day by day, in order to achieve such an aim. Most dentists prefer more conservative and aesthetic approaches, such as direct or indirect veneer restorations, instead of full-ceramic crowns for anteriors where aesthetics is really important. The aim of the study is to evaluate clinically the effectiveness of a direct composite veneering system in resolving aesthetic problem of an upper incisor with a multidisciplinary treatment approach. Methods Patient with a severe discolored upper incisor came to our attention; at the X-ray exam there was an evidence of a past not good root canal treatment and also old and incongruent composite obturation. After removing all the material inside the root canal was performed a new correct endodontic filling, then Authors tried to bleach the tooth trough “walking-bleach” technique with a hydrogen peroxide (30 volumes) and sodium perborate solution without excellent results. So it was decided to insert a glass-fiber post and than to perform a direct composite veneer with Componeer System (Coltene). Componeer System is a system of prefabricated composite veneers that are abled to be applied directly in the first appointment: after a conservative preparation of the tooth, it must be used an adhesive agent (for example a “three steps”) and then with composite stratification it’s possible to apply the componeer veneer (choosing the right measure, modified as necessary) as the last covering aesthetic layer. Result The evaluation of result of this multidisciplinary treatment was essentially clinical and radiological; in fact it’s possible to observe, from a clinical point of view, the good aesthetic aspect of the direct composite restoration with componeer veneer that offers also some advantages: conservative preparation with

  2. Esthetic management of anterior dental anomalies: A clinical case.

    PubMed

    Chafaie, Amir

    2016-09-01

    Many types of dental abnormality can be observed in the anterior sectors, where they can cause genuine esthetic problems for our patients. While conventional prosthetic treatments offer the best solutions in terms of esthetic result and durability, they involve the sacrifice of significant quantities of mineralized dental material and cannot be undertaken before the periodontal tissues are mature. Other less invasive alternatives should be envisaged as transitional, or sometimes even permanent, solutions for the management of these anomalies in children and adolescents. This article discusses these options and presents a clinical case where composite resin veneers and microabrasion of the enamel were used to treat dental agenesis and enamel dysplasia.

  3. Effects of core characters and veneering technique on biaxial flexural strength in porcelain fused to metal and porcelain veneered zirconia

    PubMed Central

    Oh, Ju-Won; Song, Kwang-Yeob; Ahn, Seung-Geun; Park, Ju-Mi; Lee, Min-Ho

    2015-01-01

    PURPOSE The purpose of this study was to assess the impact of the core materials, thickness and fabrication methods of veneering porcelain on prosthesis fracture in the porcelain fused to metal and the porcelain veneered zirconia. MATERIALS AND METHODS Forty nickel-chrome alloy cores and 40 zirconia cores were made. Half of each core group was 0.5 mm-in thickness and the other half was 1.0 mm-in thickness. Thus, there were four groups with 20 cores/group. Each group was divided into two subgroups with two different veneering methods (conventional powder/liquid layering technique and the heat-pressing technique). Tensile strength was measured using the biaxial flexural strength test based on the ISO standard 6872:2008 and Weibull analysis was conducted. Factors influencing fracture strength were analyzed through three-way ANOVA (α≤.05) and the influence of core thickness and veneering method in each core materials was assessed using two-way ANOVA (α≤.05). RESULTS The biaxial flexural strength test showed that the fabrication method of veneering porcelain has the largest impact on the fracture strength followed by the core thickness and the core material. In the metal groups, both the core thickness and the fabrication method of the veneering porcelain significantly influenced on the fracture strength, while only the fabrication method affected the fracture strength in the zirconia groups. CONCLUSION The fabrication method is more influential to the strength of a prosthesis compared to the core character determined by material and thickness of the core. PMID:26576250

  4. Joining Dental Ceramic Layers With Glass

    PubMed Central

    Saied, MA; Lloyd, IK; Haller, WK; Lawn, BR

    2011-01-01

    Objective Test the hypothesis that glass-bonding of free-form veneer and core ceramic layers can produce robust interfaces, chemically durable and aesthetic in appearance and, above all, resistant to delamination. Methods Layers of independently produced porcelains (NobelRondo™ Press porcelain, Nobel BioCare AB and Sagkura Interaction porcelain, Elephant Dental) and matching alumina or zirconia core ceramics (Procera alumina, Nobel BioCare AB, BioZyram yttria stabilized tetragonal zirconia polycrystal, Cyrtina Dental) were joined with designed glasses, tailored to match thermal expansion coefficients of the components and free of toxic elements. Scanning electron microprobe analysis was used to characterize the chemistry of the joined interfaces, specifically to confirm interdiffusion of ions. Vickers indentations were used to drive controlled corner cracks into the glass interlayers to evaluate the toughness of the interfaces. Results The glass-bonded interfaces were found to have robust integrity relative to interfaces fused without glass, or those fused with a resin-based adhesive. Significance The structural integrity of the interfaces between porcelain veneers and alumina or zirconia cores is a critical factor in the longevity of all-ceramic dental crowns and fixed dental prostheses. PMID:21802131

  5. Fracture of porcelain-veneered structures in fatigue.

    PubMed

    Kim, B; Zhang, Y; Pines, M; Thompson, V P

    2007-02-01

    Porcelain-veneered crowns are widely used in modern dentistry, and their fracture remains problematic, especially in all-ceramic systems. We hypothesized that substructure properties have a significant effect on the longevity of porcelain-veneered crowns. Flat porcelain/metal or porcelain/ceramic structures were cemented to dentin-like composite, and a mouth-motion cyclic load of 200 N was delivered by means of a tungsten carbide spherical indenter (r = 3.18 mm), emulating occlusal loading on crowns supported by dentin. Findings indicated that porcelain on a low-hardness gold-infiltrated alloy was vulnerable to both occlusal surface contact damage and porcelain lower surface radial fracture, while porcelain on a higher-hardness palladium-silver alloy fractured chiefly from occlusal surface damage. The advantage of a high-modulus metal substructure was less pronounced. Fracture in the porcelain/zirconia system was limited to surface damage in the veneer layer, similar to that in the porcelain/palladium-silver system. Bulk fracture, observed in veneered alumina layers, was not found for zirconia.

  6. Influence of bruxism on survival of porcelain laminate veneers

    PubMed Central

    Agustín-Panadero, Rubén; Fons-Font, Antonio; Román-Rodríguez, Juan L.; Solá-Ruíz, María F.

    2014-01-01

    Objectives: This study aims to determine whether bruxism and the use of occlusal splints affect the survival of porcelain laminate veneers in patients treated with this technique. Material and Methods: Restorations were made in 70 patients, including 30 patients with some type of parafunctional habit. A total of 323 veneers were placed, 170 in patients with bruxism activity, and the remaining 153 in patients without it. A clinical examination determined the presence or absence of ceramic failure (cracks, fractures and debonding) of the restorations; these incidents were analyzed for association with bruxism and the use of splints. Results: Analysis of the ceramic failures showed that of the 13 fractures and 29 debonding that were present in our study, 8 fractures and 22 debonding were related to the presence of bruxism. Conclusions: Porcelain laminate veneers are a predictable treatment option that provides excellent results, recognizing a higher risk of failure in patients with bruxism activity. The use of occlusal splints reduces the risk of fractures. Key words:Veneer, fracture, debonding, bruxism, occlusal splint. PMID:23986018

  7. In situ polymerization of polyaniline in wood veneers.

    PubMed

    Trey, Stacy; Jafarzadeh, Shadi; Johansson, Mats

    2012-03-01

    The present study describes the possibility to polymerize aniline within wood veneers to obtain a semi-conducting material with solid wood acting as the base template. It was determined that it is possible to synthesize the intrinsically conductive polymer (ICP) polyaniline in situ within the wood structure of Southern yellow pine veneers, combining the strength of the natural wood structure with the conductivity of the impregnated polymer. It was found that polyaniline is uniformly dispersed within the wood structure by light microscopy and FT-IR imaging. A weight percent gain in the range of 3-12 wt % was obtained with a preferential formation in the wood structure and cell wall, rather than in the lumen. The modified wood was found to be less hydrophilic with the addition of phosphate doped polyaniline as observed by equilibrium water swelling studies. While wood itself is insulating, the modified veneers had conductivities of 1 × 10(-4) to 1 × 10(-9) S cm(-1), demonstrating the ability to tune the conductivity and allowing for materials with a wide range of applications, from anti-static to charge-dispersing materials. Furthermore, the modified veneers had lower total and peak heat releases, as determined by cone calorimetry, because of the char properties of the ICP. This is of interest if these materials are to be used in building and furniture applications where flame retardance is of importance.

  8. Wet-preserved hemp fibreboard properties improvement with veneering

    NASA Astrophysics Data System (ADS)

    Kirilovs, E.; Kukle, S.; Gusovius, H.-J.

    2015-03-01

    The initial research describes a new type of fiber boards for the furniture interior design, developed in cooperation with ATB (Leibniz-Institute for Agricultural Engineering) by using a new method of raw materials preparation and specific production technologies of ATB. The main raw materials are aerobically aged hemp stalks. The samples are made of hemp chips with a long preservation time and fastened together with the UF glue. Specimens are 8 mm thick and correspond to a medium-density fiberboard, fitting standard EN622. Due to the fact that non-veneered material can be used only in non-load-bearing constructions, material improving technologies were studied, such as increase of board density, increase of glue percentage, partially substitution of wet-preserved hemp chips with a dry hemp and/or wooden chips to equalize moisture content of obtained mixture. The particular article describes how the new material is veneered with the oak veneer obtaining three-ply composite board with the improved mechanical properties that allows to use these boards in a load-bearing constructions. Tests are performed with the veneered material to determine such parameters as static bending strength (MOR), modulus of elasticity in static bending (MOE), swelling in thickness and hardness.

  9. Shear bond strength of porcelain veneers rebonded to enamel.

    PubMed

    St Germain, H A; St Germain, T H

    2015-01-01

    In this laboratory research, shear bond strength (SBS) and mode of failure of veneers rebonded to enamel in shear compression were determined. Three groups (A, B, and C; n=10 each) of mounted molar teeth were finished flat using wet 600-grit silicon carbide paper, and 30 leucite-reinforced porcelain veneers (5.0 × 0.75 mm) were air abraded on the internal surface with 50 μm aluminum oxide, etched with 9.5% hydrofluoric acid, and silanated. The control group (A) veneer specimens were bonded to enamel after etching with 37% phosphoric acid using bonding resin and a dual cure resin composite cement. Groups B and C were prepared similarly to group A with the exception that a release agent was placed before the veneer was positioned on the prepared enamel surface and the resin cement was subsequently light activated. The debonded veneers from groups B and C were placed in a casting burnout oven and heated to 454°C/850°F for 10 minutes to completely carbonize the resin cement and stay below the glass transition temperature (Tg) of the leucite-reinforced porcelain. The recovered veneers were then prepared for bonding. The previously bonded enamel surfaces in group B were air abraded using 50 μm aluminum oxide followed by 37% phosphoric acid etching, while group C enamel specimens were acid etched only. All specimens were thermocycled between 5°C and 55°C for 2000 cycles using a 30-second dwell time and stored in 37°C deionized water for 2 weeks. SBS was determined at a crosshead speed of 1.0 mm/min. SBS results in MPa for the groups were (A) = 20.6±5.1, (B) = 18.1±5.5, and (C) = 17.2±6.1. One-way analysis of variance indicated that there were no significant interactions (α=0.05), and Tukey-Kramer post hoc comparisons (α=0.05) detected no significant pairwise differences. An adhesive mode of failure at the enamel interface was observed to occur more often in the experimental groups (B = 40%, C = 50%). Rebonding the veneers produced SBS values that were not

  10. Structural and Chemical Analysis of the Zirconia-Veneering Ceramic Interface.

    PubMed

    Inokoshi, M; Yoshihara, K; Nagaoka, N; Nakanishi, M; De Munck, J; Minakuchi, S; Vanmeensel, K; Zhang, F; Yoshida, Y; Vleugels, J; Naert, I; Van Meerbeek, B

    2016-01-01

    The interfacial interaction of veneering ceramic with zirconia is still not fully understood. This study aimed to characterize morphologically and chemically the zirconia-veneering ceramic interface. Three zirconia-veneering conditions were investigated: 1) zirconia-veneering ceramic fired on sandblasted zirconia, 2) zirconia-veneering ceramic on as-sintered zirconia, and 3) alumina-veneering ceramic (lower coefficient of thermal expansion [CTE]) on as-sintered zirconia. Polished cross-sectioned ceramic-veneered zirconia specimens were examined using field emission gun scanning electron microscopy (Feg-SEM). In addition, argon-ion thinned zirconia-veneering ceramic interface cross sections were examined using scanning transmission electron microscopy (STEM)-energy dispersive X-ray spectrometry (EDS) at high resolution. Finally, the zirconia-veneering ceramic interface was quantitatively analyzed for tetragonal-to-monoclinic phase transformation and residual stress using micro-Raman spectroscopy (µRaman). Feg-SEM revealed tight interfaces for all 3 veneering conditions. High-resolution transmission electron microscopy (HRTEM) disclosed an approximately 1.0-µm transformed zone at sandblasted zirconia, in which distinct zirconia grains were no longer observable. Straight grain boundaries and angular grain corners were detected up to the interface of zirconia- and alumina-veneering ceramic with as-sintered zirconia. EDS mapping disclosed within the zirconia-veneering ceramic a few nanometers thick calcium/aluminum-rich layer, touching the as-sintered zirconia base, with an equally thick silicon-rich/aluminum-poor layer on top. µRaman revealed t-ZrO2-to-m-ZrO2 phase transformation and residual compressive stress at the sandblasted zirconia surface. The difference in CTE between zirconia- and the alumina-veneering ceramic resulted in residual tensile stress within the zirconia immediately adjacent to its interface with the veneering ceramic. The rather minor chemical

  11. The effect of various veneering techniques on the marginal fit of zirconia copings

    PubMed Central

    Torabi, Kianoosh; Vojdani, Mahroo; Giti, Rashin; Pardis, Soheil

    2015-01-01

    PURPOSE This study aimed to evaluate the fit of zirconia ceramics before and after veneering, using 3 different veneering processes (layering, press-over, and CAD-on techniques). MATERIALS AND METHODS Thirty standardized zirconia CAD/CAM frameworks were constructed and divided into three groups of 10 each. The first group was veneered using the traditional layering technique. Press-over and CAD-on techniques were used to veneer second and third groups. The marginal gap of specimens was measured before and after veneering process at 18 sites on the master die using a digital microscope. Paired t-test was used to evaluate mean marginal gap changes. One-way ANOVA and post hoc tests were also employed for comparison among 3 groups (α=.05). RESULTS Marginal gap of 3 groups was increased after porcelain veneering. The mean marginal gap values after veneering in the layering group (63.06 µm) was higher than press-over (50.64 µm) and CAD-on (51.50 µm) veneered groups (P<.001). CONCLUSION Three veneering methods altered the marginal fit of zirconia copings. Conventional layering technique increased the marginal gap of zirconia framework more than pressing and CAD-on techniques. All ceramic crowns made through three different veneering methods revealed clinically acceptable marginal fit. PMID:26140175

  12. Veneer vs. core failure in adhesively bonded all-ceramic crown layers.

    PubMed

    Lee, J J-W; Kwon, J-Y; Bhowmick, S; Lloyd, I K; Rekow, E D; Lawn, B R

    2008-04-01

    Joining a brittle veneer to a strong ceramic core with an adhesive offers potential benefits over current fabrication methods for all-ceramic crowns. We tested the hypothesis that such joining can withstand subsurface radial cracking in the veneer, from enhanced flexure in occlusal loading, as well as in the core. Critical conditions to initiate fractures were investigated in model crown-like layer structures consisting of glass veneers epoxy-joined onto alumina or zirconia cores, all bonded to a dentin-like polymer base. The results showed a competition between critical loads for radial crack initiation in the veneers and cores. Core radial cracking was relatively independent of adhesive thickness. Zirconia cores were much less susceptible to fracture than alumina, attributable to a relatively high strength and low modulus. Veneer cracking did depend on adhesive thickness. However, no significant differences in critical loads for veneer cracking were observed for specimens containing alumina or zirconia cores.

  13. Esthetic Rehabilitation of Anterior Teeth with Laminates Composite Veneers

    PubMed Central

    Riva, Giancarlo

    2014-01-01

    No- or minimal-preparation veneers associated with enamel preservation offer predictable results in esthetic dentistry; indirect additive anterior composite restorations represent a quick, minimally invasive, inexpensive, and repairable option for a smile enhancement treatment plan. Current laboratory techniques associated with a strict clinical protocol satisfy patients' restorative and esthetic needs. The case report presented describes minimal invasive treatment of four upper incisors with laminate nanohybrid resin composite veneers. A step-by-step protocol is proposed for diagnostic evaluation, mock-up fabrication and trial, teeth preparation and impression, and adhesive cementation. The resolution of initial esthetic issues, patient satisfaction, and nice integration of indirect restorations confirmed the success of this anterior dentition rehabilitation. PMID:25013730

  14. Esthetic rehabilitation of discolored anterior teeth with porcelain veneers

    PubMed Central

    Kamble, Vaibhav D.; Parkhedkar, Rambhau D.

    2013-01-01

    The common man is bombarded by the media extolling the virtues of “the perfect smile.” In the 21st century of esthetic dentistry, fractured, malformed, malposed, and discolored teeth can be changed and restored to highly desirable form due to introduction of wide range of esthetic materials and techniques. Porcelain veneers is a conservative method of restoring the appearance of discolored, pitted teeth, and teeth with diastemas that provide extremely good esthetic results. A 21-year-old female patient with staining in anterior teeth had reported to the Department of Prosthodontics for esthetic rehabilitation. The patient was treated with porcelain veneers on maxillary anterior teeth. The patient was satisfied with the enhanced esthetic appearance. PMID:23853471

  15. Titanium and titanium alloys as dental materials.

    PubMed

    Lautenschlager, E P; Monaghan, P

    1993-06-01

    Because of light weight, high strength to weight ratio, low modulus of elasticity, and excellent corrosion resistance, titanium and some of its alloys have been important materials for the aerospace industry since the 1950s. Now, with the additional advantages of excellent biocompatibility, good local spot weldability, and easy shaping and finishing by a number of mechanical and electrochemical processes, these materials are finding uses in dental applications, such as implants and restorative castings. Although more research is still needed in areas such as development of optimal casting investments, porcelain veneering systems, device designs, and controlled biological responses, the present and future uses of titanium appear bright for dentistry.

  16. Contact fatigue response of porcelain-veneered alumina model systems.

    PubMed

    Stappert, Christian F J; Baldassarri, Marta; Zhang, Yu; Stappert, Dina; Thompson, Van P

    2012-02-01

    Fatigue damage modes and reliability of hand-veneered (HV) and over-pressed (OP) aluminum-oxide layer structures were compared. Influence of luting cement thickness on mechanical performance was investigated. Sixty-four aluminum-oxide plates (10 × 10 × 0.5 mm) were veneered with hand built-up or pressed porcelain (0.7 mm) and adhesively luted (50- or 150-μm cement thickness) to water-aged composite resin blocks (12 × 12 × 4 mm). Single-load-to-failure and fatigue tests were performed with a spherical tungsten carbide indenter (d = 6.25 mm) applied in the center of the veneer layer. Specimens were inspected with polarized-reflected-light and scanning electron microscopy. Use-level probability Weibull curves were plotted with two-sided 90% confidence bounds, and reliability at 75,000 cycles and 250 N load was calculated. For all specimens but two OP with 50-μm cement thickness, failure was characterized by flexural radial cracks initiating at the bottom surface of the alumina core and propagating into the veneering porcelain before cone cracks could extend to the porcelain/alumina interface. HV specimens showed higher reliability compared to OP. Those with 50-μm cement thickness were more reliable relative to their 150-μm counterparts (HV_50 μm: 95% (0.99/0.67); HV_150 μm: 55% (0.92/0.01); OP_50 μm: 69% (0.84/0.48); OP_150 μm: 15% (0.53/0.004)). Similar failure modes were observed in HV and OP specimens. Radial cracks developing in the core and spreading into the veneer are suggested to cause bulk fracture, which is the characteristic failure mode for alumina core crowns. However, the highest resistance to fatigue loading was found for the HV specimens with thin cement thickness, while the lowest occurred for the OP with thick cement layer.

  17. Dental Procedures.

    PubMed

    Ramponi, Denise R

    2016-01-01

    Dental problems are a common complaint in emergency departments in the United States. There are a wide variety of dental issues addressed in emergency department visits such as dental caries, loose teeth, dental trauma, gingival infections, and dry socket syndrome. Review of the most common dental blocks and dental procedures will allow the practitioner the opportunity to make the patient more comfortable and reduce the amount of analgesia the patient will need upon discharge. Familiarity with the dental equipment, tooth, and mouth anatomy will help prepare the practitioner for to perform these dental procedures.

  18. Effect of Provisional Cements on Shear Bond Strength of Porcelain Laminate Veneers

    PubMed Central

    Altintas, Subutay Han; Tak, Onjen; Secilmis, Asli; Usumez, Aslihan

    2011-01-01

    Objectives: The purpose of this study was to evaluate the effect of three provisional cements and two cleaning techniques on the final bond strength of porcelain laminate veneers. Methods: The occlusal third of the crowns of forty molar teeth were sectioned and embedded in autopolymerizing acrylic resin. Dentin surfaces were polished and specimens were randomly divided into four groups (n=10). Provisional restorations were fabricated and two provisional restorations were cemented onto each tooth. Restorations were fixed with one of three different provisional cements: eugenol-free provisional cement (Cavex), calcium hydroxide (Dycal), and light-cured provisional cement (Tempond Clear). Provisional restorations were removed with either a dental explorer and air-water spray, or a cleaning bur (Opticlean). In the control group, provisional restorations were not used on the surfaces of specimens. IPS Empress 2 ceramic discs were luted with a dual-cured resin cement (Panavia F). Shear bond strength was measured using a universal testing machine. Data were statistically analyzed by ANOVA, Tukey’s HSD and Dunnett tests. Surfaces were examined by scanning electronic microscopy. Results: Significant differences were found between the control group and both the light-cured provisional cement groups and the eugenol-free provisional cement-cleaning bur group (P<.05). Groups that had received light-cured provisional cement showed the lowest bond strength values. Conclusions: Selection of the provisional cement is an important factor in the ultimate bond strength of the final restoration. Calcium hydroxide provisional cement and cleaning with a dental explorer are advisable. PMID:21912495

  19. The esthetic rehabilitation of misplaced dental arch after fracture of anterior maxillae: a case report

    PubMed Central

    Turna, Çagri

    2009-01-01

    Introduction In cases where the patient experiences trauma, the teeth may be fractured or a bone segment could be fractured causing misplaced teeth. Ceramic veneer restorations may be a solution for re-establishing the ideal position. The treatment of misplaced dental arch segment is presented and treatment options are discussed. Case presentation A 30-years-old female Turkish patient had a history of a dentoalveolar trauma and a surgical operation. Her main complaints were about the unpleasant appearance of her anterior teeth. The maxillary anterior teeth were positioned labially and had irregularities in vertical position inharmonious with each other and the horizontal plane. The misplaced sector treated with minimally invasive dentin bonded porcelain laminate veneers. Conclusion Ceramic veneers can be a solution for patients with malpositioned anterior teeth even the situation is severe and excessive tooth reduction is needed. PMID:19918401

  20. A photoelastic assessment of residual stresses in zirconia-veneer crowns.

    PubMed

    Belli, R; Monteiro, S; Baratieri, L N; Katte, H; Petschelt, A; Lohbauer, U

    2012-03-01

    Residual stresses within the veneer are linked to the high prevalence of veneer chipping observed in clinical trials of zirconia prostheses. We hypothesized that the thermal mismatch between the zirconia infrastructure and the veneer porcelain, as well as the rate used for cooling zirconia-veneer crowns, would be directly proportional to the magnitude of residual stresses built within the veneer layer. Two porcelains with different coefficients of thermal expansion were used to veneer zirconia copings, to create high or low thermal mismatches. The crowns were cooled according to a fast- or a slow-cooling protocol. The retardation of polarized light waves was used to calculate the residual stress magnitude and distribution across the veneer, according to the photoelasticity principle, in 1.0-mm-thick crown sections. While thermal mismatch was an important factor influencing the maximum stress development in the veneer, cooling rate had a minor role. Curved surfaces were preferential sites for stress concentration regardless of thermal mismatch or cooling rate.

  1. Origin and mixing timescale of Earth's late veneer

    NASA Astrophysics Data System (ADS)

    Prescher, C.; Allu Peddinti, D.; Bell, E. A.; Bello, L.; Cernok, A.; Ghosh, N.; Tucker, J.; Wielicki, M. M.; Zahnle, K. J.

    2012-12-01

    Experimental studies on the partitioning behavior of highly siderophile elements (HSE) between silicate and metallic melts imply that the Earth's mantle should have been highly depleted in these elements by core formation in an early magma ocean. However, present HSE contents of the Earth's mantle are ~3 orders of magnitude higher than that expected by experiments. The apparent over-abundance of HSE has commonly been explained by the addition of meteoritic material in the "late veneer" which describes the exogenous mass addition following the moon forming impact and concluding with the late heavy bombardment at ~3.8-3.9 Ga. The strongest evidence for this theory is that the platinum group element (PGE) contents in today's mantle are present in chondritic relative abundances, as opposed to a fractionated pattern expected with metal-silicate partitioning. Archean komatiites indicate that the PGE content of the Earth's mantle increased from about half their present abundances at 3.5 Ga to their present abundances at 2.9 Ga. This secular increase in PGE content suggests a progressive mixing of the late veneer material into the Earth's mantle. However, this time scale also implies that the whole mantle was relatively well mixed by 2.9 Ga. We use a compilation of existing isotopic and trace element data in order to constrain the origin and composition of the late veneer. We use PGE abundances, W abundances and W isotopic compositions in chondritic meteorites and the primitive upper mantle to compute the amount of mass delivered during the late veneer and find the late veneer mass to be ~0.6 % the mass of the bulk silicate Earth (consistent with earlier estimates). We also use the 187Re-187Os and 190Pt-186Os systems to constrain the composition and timing of delivery of the impacting population. We model the efficiency of mantle mixing in this time frame by using 3-dimensional numerical geodynamical simulations and geochemical constraints. Initial parameters include the

  2. Late veneer and late accretion to the terrestrial planets

    NASA Astrophysics Data System (ADS)

    Brasser, R.; Mojzsis, S. J.; Werner, S. C.; Matsumura, S.; Ida, S.

    2016-12-01

    It is generally accepted that silicate-metal ('rocky') planet formation relies on coagulation from a mixture of sub-Mars sized planetary embryos and (smaller) planetesimals that dynamically emerge from the evolving circum-solar disc in the first few million years of our Solar System. Once the planets have, for the most part, assembled after a giant impact phase, they continue to be bombarded by a multitude of planetesimals left over from accretion. Here we place limits on the mass and evolution of these planetesimals based on constraints from the highly siderophile element (HSE) budget of the Moon. Outcomes from a combination of N-body and Monte Carlo simulations of planet formation lead us to four key conclusions about the nature of this early epoch. First, matching the terrestrial to lunar HSE ratio requires either that the late veneer on Earth consisted of a single lunar-size impactor striking the Earth before 4.45 Ga, or that it originated from the impact that created the Moon. An added complication is that analysis of lunar samples indicates the Moon does not preserve convincing evidence for a late veneer like Earth. Second, the expected chondritic veneer component on Mars is 0.06 weight percent. Third, the flux of terrestrial impactors must have been low (≲10-6 M⊕ Myr-1) to avoid wholesale melting of Earth's crust after 4.4 Ga, and to simultaneously match the number of observed lunar basins. This conclusion leads to an Hadean eon which is more clement than assumed previously. Last, after the terrestrial planets had fully formed, the mass in remnant planetesimals was ∼10-3 M⊕, lower by at least an order of magnitude than most previous models suggest. Our dynamically and geochemically self-consistent scenario requires that future N-body simulations of rocky planet formation either directly incorporate collisional grinding or rely on pebble accretion.

  3. Porcelain veneers as an alternative for esthetic treatment: clinical report.

    PubMed

    Rotoli, B T; Lima, D A N L; Pini, N P; Aguiar, F H B; Pereira, G D S; Paulillo, L A M S

    2013-01-01

    This case report describes the restoration of the anterior dentition with porcelain laminate veneers. The advances in bonding of porcelain to tooth structure make this treatment a feasible alternative to restore teeth with alteration in shape and position in cases in which the esthetic demand is high. The rationale for various choices in this treatment protocol is detailed with reference to the pertinent literature. Thus, the clinical success of the technique depends on the correct identification of a case for which this treatment is appropriate and the successful execution of the clinical steps involved.

  4. Micromechanical properties of veneer luting resins after curing through ceramics.

    PubMed

    Oztürk, Elif; Hickel, Reinhard; Bolay, Sükran; Ilie, Nicoleta

    2012-02-01

    The aim of this study was to assess the performance of light-cured luting resin after curing under the ceramic restoration in comparison to dual-cured luting resin, by evaluating the micromechanical properties. Two hundred seventy thin luting composite films of ca. 170 μm in thickness were prepared by using two light-cured luting resins (Variolink Veneer, Ivoclar Vivadent; RelyX Veneer, 3M ESPE) and a dual-cured luting resin (Variolink II, Ivoclar Vivadent). The composites were cured by using a LED-unit (Bluephase®, Ivoclar Vivadent) with three different curing times (10, 20, and 30 s) under two ceramics (IPS e.max Press, Ivoclar Vivadent; IPS Empress® CAD, Ivoclar Vivadent) of different thicknesses (0, 0.75, and 2 mm). Forty-five groups were included, each containing six thin films. The samples were stored after curing for 24 h at 37°C by maintaining moisture conditions with distilled water. Micromechanical properties of the composites were measured with an automatic microhardness indenter (Fisherscope H100C, Germany). For each sample, ten indentations were made, thus totalizing 60 measurements per group. Micromechanical properties of the luting resins were statistically analyzed (SPSS 17.0). Significant differences were observed between the micromechanical properties of the luting resins (p < 0.05). Variolink II showed the highest values in modulus of elasticity (E = 11 ± 0.5)* and Vickers hardness (HV = 48.2 ± 3.2)* and the lowest values in creep (Cr = 4.3 ± 0.1)* and elastic-plastic deformation (We/Wtot = 38.6 ± 0.7)* followed by RelyX Veneer (E = 6.9 ± 0.3, HV = 33 ± 2.5, Cr = 4.6 ± 0.2, We/Wtot = 41.8 ± 1.0)* and Variolink Veneer (E = 4.4 ± 0.4, HV = 20.1 ± 2.6, Cr = 5 ± 0.2, We/Wtot = 43.7 ± 1.3)*. Dual-cured luting resin expressed higher values in the micro-mechanical properties compared to the light-cured luting resins. The effect of luting resin type on the micromechanical properties of the luting resins was higher than the effect of

  5. Air-coupled ultrasonic assessment of wood veneer.

    PubMed

    Blomme, Erik; Bulcaen, Dirk; Cool, Tijl; Declercq, Filip; Lust, Pieter

    2010-02-01

    Air-coupled ultrasound (ACU) provides a tool to evaluate wood samples of small or moderate thickness (<30 mm) thereby avoiding direct contact or liquid coupling. Results of through-transmission ACU measurements on wood veneer samples and related products are reported with respect to a wide variety of quality aspects. Fluctuations in the averaged received signal levels appear to be correlated to the presence of natural or machine-induced thickness and density variations, flaws and grain damage, errors produced by the manufacturing process, insufficient bonding on a substrate, etc. In addition it is seen that the variability of the signal levels enables to distinguish between quarter and crown areas.

  6. Clinical approach to anterior adhesive restorations using resin composite veneers.

    PubMed

    Mangani, Francesco; Cerutti, Antonio; Putignano, Angelo; Bollero, Raffaele; Madini, Lorenzo

    2007-01-01

    Scientific progress in adhesive dentistry has led to more conservative techniques, both direct and indirect, to solve esthetic problems in anterior teeth. This article will discuss only indirect techniques, which are clearly superior in complex cases in which it will be difficult to recreate harmonious tooth shape and color. After reviewing the literature and highlighting the properties of this technique, the indications and benefits compared to the direct technique will be assessed. This is followed by a step-by-step description of operative procedures, from treatment planning to relining and polishing of the cemented adhesive restoration. The long-term success of veneers depends mainly on the tooth preparation, which should be confined to enamel, involve proximal contact areas, maintain the cervical enamel margin, and incorporate the incisal edge to increase veneer resistance and enable correct placement. Although no clinical follow-up similar to that of ceramic materials is available, the latest-generation resin composites offer interesting features. They can withstand mechanical stress, have excellent esthetic properties, and, most importantly, can be repaired intraorally without impairing their physicochemical and mechanical properties.

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

    NASA Astrophysics Data System (ADS)

    Tawde, Shweta

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

  8. Influence of silane surface modification of veneer on interfacial adhesion of wood-plastic plywood

    NASA Astrophysics Data System (ADS)

    Fang, Lu; Chang, Liang; Guo, Wen-jing; Chen, Yongping; Wang, Zheng

    2014-01-01

    In this study, wood-plastic plywood was fabricated with high density polyethylene (HDPE) film and poplar veneer by hot-pressing. To improve the interfacial adhesion between the wood veneer and HDPE film, silane A-171 (vinyltrimethoxysilane) was used to treat the surface of poplar veneer by spraying. The effects of silane agent on the veneer surface properties as well as the physical-mechanical performance of wood-plastic plywood were evaluated. The adsorption of several prehydrolyzed alkoxysilanes onto the veneer surface and the existence of a covalent bonding between the wood veneer and silane agent were confirmed using FTIR, XPS and contact angle. Silane surface treatment resulted in enhancement of shear strength and water resistance. When one layer HDPE film was used as adhesive, it caused 293.2% increase in shear strength, 34.6% and 40.8% reduction in water absorption and thickness swelling, respectively. In addition, the wood failure also increased from 5% to 100% due to the silane modification. Dynamic mechanical analysis (DMA) results showed that treated plywood have higher storage modulus, lower tan δ peak value and lagged temperature for tan δ peak value with respect to untreated plywood. Experimental results of interfacial morphology by SEM further revealed better interaction between silane A-171 treated veneer and HDPE film.

  9. Interfacial modulus mapping of layered dental ceramics using nanoindentation

    PubMed Central

    Bushby, Andrew J; P'ng, Ken MY; Wilson, Rory M

    2016-01-01

    PURPOSE The aim of this study was to test the modulus of elasticity (E) across the interfaces of yttria stabilized zirconia (YTZP) / veneer multilayers using nanoindentation. MATERIALS AND METHODS YTZP core material (KaVo-Everest, Germany) specimens were either coated with a liner (IPS e.max ZirLiner, Ivoclar-Vivadent) (Type-1) or left as-sintered (Type-2) and subsequently veneered with a pressable glass-ceramic (IPS e.max ZirPress, Ivoclar-Vivadent). A 5 µm (nominal tip diameter) spherical indenter was used with a UMIS CSIRO 2000 (ASI, Canberra, Australia) nanoindenter system to test E across the exposed and polished interfaces of both specimen types. The multiple point load – partial unload method was used for E determination. All materials used were characterized using Scanning Electron Microscopy (SEM) and X – ray powder diffraction (XRD). E mappings of the areas tested were produced from the nanoindentation data. RESULTS A significantly (P<.05) lower E value between Type-1 and Type-2 specimens at a distance of 40 µm in the veneer material was associated with the liner. XRD and SEM characterization of the zirconia sample showed a fine grained bulk tetragonal phase. IPS e-max ZirPress and IPS e-max ZirLiner materials were characterized as amorphous. CONCLUSION The liner between the YTZP core and the heat pressed veneer may act as a weak link in this dental multilayer due to its significantly (P<.05) lower E. The present study has shown nanoindentation using spherical indentation and the multiple point load - partial unload method to be reliable predictors of E and useful evaluation tools for layered dental ceramic interfaces. PMID:28018566

  10. An esthetic technique for veneering anterior stainless steel crowns with composite resin.

    PubMed

    Wiedenfeld, K R; Draughn, R A; Welford, J B

    1994-01-01

    The restoration of primary anterior teeth presents complicated esthetic and retention problems to the clinician. A technique is described for the chairside veneering of composite resin to stainless steel crowns, which results in well contoured restorations with superior durability and esthetics. A trimmed and fitted stainless steel crown can be veneered in three to five minutes. This provides the adaptability and gingival contour benefits of the stainless steel crown in conjunction with the cosmetics of the composite facings. The technique described produced composite veneers with a mean sheer bond strength of 3520 PSI (24.4 Mpa).

  11. Dental Assistants

    MedlinePlus

    ... help keep the dental office running smoothly. Important Qualities Detail oriented. Dental assistants must follow specific rules and protocols, such as infection control procedures, when helping dentists treat patients. Assistants also ...

  12. Dental OCT

    NASA Astrophysics Data System (ADS)

    Colston, Bill W.; Sathyam, Ujwal S.; Dasilva, Luiz B.; Everett, Matthew J.; Stroeve, Pieter; Otis, L. L.

    1998-09-01

    We present here the first in vivo optical coherence tomography (OCT) images of human dental tissue. A novel dental optical coherence tomography system has been developed. This system incorporates the interferometer sample arm and transverse scanning optics into a handpiece that can be used intraorally to image human dental tissues. The average imaging depth of this system varied from 3 mm in hard tissues to 1.5 mm in soft tissues. We discuss the application of this imaging system for dentistry and illustrate the potential of our dental OCT system for diagnosis of periodontal disease, detection of caries, and evaluation of dental restorations.

  13. Use of Feldspathic Porcelain Veneers to Improve Smile Harmony: A 3-Year Follow-up Report.

    PubMed

    Federizzi, Leonardo; Gomes, Érica Alves; Báratro, Samantha Schaffer Pugilato; Baratto-Filho, Flares; Bacchi, Ataís; Spazzin, Aloísio Oro

    2016-01-01

    This case report describes an esthetic treatment to improve the shape and alignment of the anterior teeth, reestablishing smile harmony, using feldspathic porcelain veneers. Results of clinical follow up after 36 months are also presented. The advantages, disadvantages and limitations of the technique are detailed with reference to the relevant literature. This suggests that the success of treatment depends on adequate conditions of bonding between the veneers and the tooth complex, which involves parameters such as the strength and durability of the bond interface. Therefore, the clinical success of feldspathic porcelain veneers depends on the accurate selection of cases and correct execution of clinical and laboratory procedures. The rehabilitation involved from first right premolar to the left with feldspathic porcelain veneers made on refractory dies. After the 3-year follow up, excellent clinical results and patient satisfaction were achieved.

  14. Prospective clinical study of press-ceramic overlap and full veneer restorations: 7-year results.

    PubMed

    Guess, Petra C; Selz, Christian F; Voulgarakis, Apostolos; Stampf, Susanne; Stappert, Christian F J

    2014-01-01

    The aim of this prospective clinical study was to investigate the long-term performance of all-ceramic veneers with overlap (OV) and full veneer (FV) preparation designs. Twenty-five patients were restored using 42 OV restorations (incisal/palatal butt-joint margin) and 24 FV restorations (palatal rounded shoulder margin). All restorations were leucite-reinforced glass-ceramic anterior veneers. The 7-year Kaplan-Meier survival rate was 100% for FV restorations and 97.6% for OV restorations. The all-ceramic veneers revealed significant deterioration over time according to United States Public Health Service criteria, irrespective of the preparation design. Based on the 7-year results of this study, both preparation designs can be considered reliable treatment options for anterior teeth with extended deficits.

  15. Experimental Design on Laminated Veneer Lumber Fiber Composite: Surface Enhancement

    NASA Astrophysics Data System (ADS)

    Meekum, U.; Mingmongkol, Y.

    2010-06-01

    Thick laminate veneer lumber(LVL) fibre reinforced composites were constructed from the alternated perpendicularly arrayed of peeled rubber woods. Glass woven was laid in between the layers. Native golden teak veneers were used as faces. In house formulae epoxy was employed as wood adhesive. The hand lay-up laminate was cured at 150° C for 45 mins. The cut specimen was post cured at 80° C for at least 5 hours. The 2k factorial design of experimental(DOE) was used to verify the parameters. Three parameters by mean of silane content in epoxy formulation(A), smoke treatment of rubber wood surface(B) and anti-termite application(C) on the wood surface were analysed. Both low and high levels were further subcategorised into 2 sub-levels. Flexural properties were the main respond obtained. ANOVA analysis of the Pareto chart was engaged. The main effect plot was also testified. The results showed that the interaction between silane quantity and termite treatment is negative effect at high level(AC+). Vice versa, the interaction between silane and smoke treatment was positive significant effect at high level(AB+). According to this research work, the optimal setting to improve the surface adhesion and hence flexural properties enhancement were high level of silane quantity, 15% by weight, high level of smoked wood layers, 8 out of 14 layers, and low anti termite applied wood. The further testes also revealed that the LVL composite had superior properties that the solid woods but slightly inferior in flexibility. The screw withdrawn strength of LVL showed the higher figure than solid wood. It is also better resistance to moisture and termite attack than the rubber wood.

  16. Ruthenium isotopic evidence for an inner Solar System origin of the late veneer.

    PubMed

    Fischer-Gödde, Mario; Kleine, Thorsten

    2017-01-25

    The excess of highly siderophile elements in the Earth's mantle is thought to reflect the addition of primitive meteoritic material after core formation ceased. This 'late veneer' either comprises material remaining in the terrestrial planet region after the main stages of the Earth's accretion, or derives from more distant asteroidal or cometary sources. Distinguishing between these disparate origins is important because a late veneer consisting of carbonaceous chondrite-like asteroids or comets could be the principal source of the Earth's volatiles and water. Until now, however, a 'genetic' link between the late veneer and such volatile-rich materials has not been established or ruled out. Such genetic links can be determined using ruthenium (Ru) isotopes, because the Ru in the Earth's mantle predominantly derives from the late veneer, and because meteorites exhibit Ru isotope variations arising from the heterogeneous distribution of stellar-derived dust. Although Ru isotopic data and the correlation of Ru and molybdenum (Mo) isotope anomalies in meteorites were previously used to argue that the late veneer derives from the same type of inner Solar System material as do Earth's main building blocks, the Ru isotopic composition of carbonaceous chondrites has not been determined sufficiently well to rule them out as a source of the late veneer. Here we show that all chondrites, including carbonaceous chondrites, have Ru isotopic compositions distinct from that of the Earth's mantle. The Ru isotope anomalies increase from enstatite to ordinary to carbonaceous chondrites, demonstrating that material formed at greater heliocentric distance contains larger Ru isotope anomalies. Therefore, these data refute an outer Solar System origin for the late veneer and imply that the late veneer was not the primary source of volatiles and water on the Earth.

  17. Influence of enamel preservation on failure rates of porcelain laminate veneers.

    PubMed

    Gurel, Galip; Sesma, Newton; Calamita, Marcelo A; Coachman, Christian; Morimoto, Susana

    2013-01-01

    The purpose of this study was to evaluate the failure rates of porcelain laminate veneers (PLVs) and the influence of clinical parameters on these rates in a retrospective survey of up to 12 years. Five hundred eighty laminate veneers were bonded in 66 patients. The following parameters were analyzed: type of preparation (depth and margin), crown lengthening, presence of restoration, diastema, crowding, discoloration, abrasion, and attrition. Survival was analyzed using the Kaplan-Meier method. Cox regression modeling was used to determine which factors would predict PLV failure. Forty-two veneers (7.2%) failed in 23 patients, and an overall cumulative survival rate of 86% was observed. A statistically significant association was noted between failure and the limits of the prepared tooth surface (margin and depth). The most frequent failure type was fracture (n = 20). The results revealed no significant influence of crown lengthening apically, presence of restoration, diastema, discoloration, abrasion, or attrition on failure rates. Multivariable analysis (Cox regression model) also showed that PLVs bonded to dentin and teeth with preparation margins in dentin were approximately 10 times more likely to fail than PLVs bonded to enamel. Moreover, coronal crown lengthening increased the risk of PLV failure by 2.3 times. A survival rate of 99% was observed for veneers with preparations confined to enamel and 94% for veneers with enamel only at the margins. Laminate veneers have high survival rates when bonded to enamel and provide a safe and predictable treatment option that preserves tooth structure.

  18. An esthetic solution for single-implant restorations - type III porcelain veneer bonded to a screw-retained custom abutment: a clinical report.

    PubMed

    Magne, Pascal; Magne, Michel; Jovanovic, Sascha A

    2008-01-01

    A new esthetic solution to restore dental implants in combination with limited interdental, facial or labial, or interocclusal space is presented. This article describes the translational application of novel-design porcelain veneers and adhesive restorative principles in the implant realm. A patient is presented who was treated with a single implant-supported restoration replacing a missing mandibular lateral incisor and partially collapsed interdental space. A screw-retained custom metal ceramic abutment was combined with a bonded porcelain restoration. This unique design was motivated by the limited restorative space and subgingival implant shoulder. It was also developed as a solution to the interference of the screw-access channel with the incisal edge, therefore providing the surgeon with more options during implant axis selection. The porcelain-to-porcelain adhesive approach was used instead of traditional principles of retention and resistance form of the abutment.

  19. Mechanical and chemical analyses across dental porcelain fused to CP titanium or Ti6Al4V.

    PubMed

    Souza, Júlio C M; Henriques, Bruno; Ariza, Edith; Martinelli, Antonio E; Nascimento, Rubens M; Silva, Filipe S; Rocha, Luís A; Celis, Jean-Pierre

    2014-04-01

    The aim of this study was to evaluate the evolution of mechanical properties and chemical variation across veneering dental porcelain fused to different titanium-based substrates. Test samples were synthesized by fusing dental feldspar-based porcelain onto commercially pure titanium grade II or Ti6Al4V alloy. Samples were cross-sectioned at angles of 10 and 90° to the interface plane. Afterwards, nanoindentation tests and Scanning Electron Microscopy (SEM) imaging coupled to an Energy Dispersive Spectroscopy (EDS) system were carried out across interfaces extending from the metal towards the porcelain area. Elemental diffusion profiles across the porcelain-to-metal interfaces were also obtained by EDS analysis. The mismatch in mechanical properties found in porcelain-to-Ti6Al4V interfaces was lower than that of porcelain-to-CP titanium. Cracking was noticed at low-thickness veneering dental porcelain regions after the nanoindentation tests of samples cross-sectioned at low angles to the interface plane. A wide reaction zone between titanium and porcelain as well as higher incidence of defects was noticed at the porcelain-to-CP titanium interfaces. This study confirmed Ti6Al4V as an improved alternative to CP-titanium as it showed to establish a better interface with the veneering dental porcelain considering the slight chemical interaction and the lower mechanical properties mismatch. The elastic modulus of porcelain-to-Ti6Al4V samples showed to be less sensitive to porcelain thickness variations.

  20. Fracture resistance and failure mode of posterior fixed dental prostheses fabricated with two zirconia CAD/CAM systems

    PubMed Central

    López-Suárez, Carlos; Gonzalo, Esther; Peláez, Jesús; Rodríguez, Verónica

    2015-01-01

    Background In recent years there has been an improvement of zirconia ceramic materials to replace posterior missing teeth. To date little in vitro studies has been carried out on the fracture resistance of zirconia veneered posterior fixed dental prostheses. This study investigated the fracture resistance and the failure mode of 3-unit zirconia-based posterior fixed dental prostheses fabricated with two CAD/CAM systems. Material and Methods Twenty posterior fixed dental prostheses were studied. Samples were randomly divided into two groups (n=10 each) according to the zirconia ceramic analyzed: Lava and Procera. Specimens were loaded until fracture under static load. Data were analyzed using Wilcoxon´s rank sum test and Wilcoxon´s signed-rank test (P<0.05). Results Partial fracture of the veneering porcelain occurred in 100% of the samples. Within each group, significant differences were shown between the veneering and the framework fracture resistance (P=0.002). The failure occurred in the connector cervical area in 80% of the cases. Conclusions All fracture load values of the zirconia frameworks could be considered clinically acceptable. The connector area is the weak point of the restorations. Key words:Fixed dental prostheses, zirconium-dioxide, zirconia, fracture resistance, failure mode. PMID:26155341

  1. Enamel microabrasion for aesthetic management of dental fluorosis

    PubMed Central

    Pandey, Pallavi; Ansari, Afroz Alam; Moda, Preeti; Yadav, Madhulika

    2013-01-01

    Fluorosis has increased in recent times due to fluoridation of drinking water and addition of fluoride to various edible items, which leads to unaesthetic appearance of teeth visible at close quarters. The enamel microabrasion technique is a conservative method that improves the appearance of the teeth by restoring bright and superficial smoothness, without causing significant structural loss. The aim of this article is to describe an easy technique for managing mild to moderate dental fluorosis using Opalustre (Ultradent Products) microabrasion slurry. This conservative approach may be considered an interesting alternative to more invasive prosthetic techniques like composite resin restorations, ceramic veneers or crown fabrications. PMID:24121810

  2. Enamel microabrasion for aesthetic management of dental fluorosis.

    PubMed

    Pandey, Pallavi; Ansari, Afroz Alam; Moda, Preeti; Yadav, Madhulika

    2013-10-11

    Fluorosis has increased in recent times due to fluoridation of drinking water and addition of fluoride to various edible items, which leads to unaesthetic appearance of teeth visible at close quarters. The enamel microabrasion technique is a conservative method that improves the appearance of the teeth by restoring bright and superficial smoothness, without causing significant structural loss. The aim of this article is to describe an easy technique for managing mild to moderate dental fluorosis using Opalustre (Ultradent Products) microabrasion slurry. This conservative approach may be considered an interesting alternative to more invasive prosthetic techniques like composite resin restorations, ceramic veneers or crown fabrications.

  3. Comparative evaluation of shear bond strengths of veneering porcelain to base metal alloy and zirconia substructures before and after aging – An in vitro study

    PubMed Central

    Sreekala, Laju; Narayanan, Mahesh; Eerali, Sunil M.; Eerali, Susil M.; Varghese, Joju; Zainaba Fathima, A. l.

    2015-01-01

    Objective: The aim of this study was to evaluate and compare the shear bond strength of veneering porcelain to base metal alloy and zirconia substructures before and after aging. Scanning electron microscopy (SEM) was used to determine the failure pattern. Materials and Methods: Twenty rectangular blocks (9 mm length × 4 mm height × 4 mm width) of base metal alloy (Bellabond plus, Bego, Germany) and zirconia (Will ceramZ zirconia K block) were fabricated for shear bond strength test. Surface of the base metal alloy block (4 mm × 4 mm area) was veneered with corresponding veneering porcelain (Ivoclar, IPS classic, vivadent). Similarly, surface of the zirconia rectangular block (4 mm × 4 mm) was veneered with corresponding veneering ceramic (Cercon ceram kiss, Degudent). Out of forty rectangular porcelain veneered core specimen, ten porcelain veneered base metal alloy specimen and ten porcelain veneered zirconia specimen were immersed in water at 37°C for one month to simulate the oral environment. Results: On comparison, the highest shear bond strength value was obtained in porcelain veneered base metal alloy before aging group followed by porcelain veneered base metal alloy after aging group, Porcelain veneered zirconia before aging group, porcelain veneered zirconia after aging group. SEM analysis revealed predominantly cohesive failure of veneering ceramic in all groups. Conclusion: Porcelain veneered base metal alloy samples showed highest shear bond strength than porcelain veneered zirconia samples. Study concluded that aging had an influence on shear bond strength. Shear bond strength was found to be decreasing after aging. SEM analysis revealed cohesive failure of veneering ceramic in all groups suggestive of higher bond strength of the interface than cohesive strength of ceramic. Hence, it was concluded that veneering ceramic was the weakest link. PMID:26942121

  4. Dental sepsis.

    PubMed

    Mueller, P O; Lowder, M Q

    1998-08-01

    Dental sepsis or periapical abscess formation constitutes a large percentage of dental conditions that afflict horses. Dental sepsis occurs when the pulp chamber of the tooth is exposed to the oral cavity or external environment, allowing bacterial localization with resulting infection. Although acute, primary, septic pulpitis in horses is rare, dental sepsis often results from colonization of the pulp chamber with pathogenic bacteria secondary to maleruption or impaction of teeth with secondary alveolar bone lysis, primary fractures of the tooth, mandible, or maxilla, periodontal disease, or infundibular necrosis. The sequela to pulpal infection are extensions into the periradicular tissues and mandibular or maxillary periapical abscess formation.

  5. Ruthenium isotopic evidence for an inner Solar System origin of the late veneer

    NASA Astrophysics Data System (ADS)

    Fischer-Gödde, Mario; Kleine, Thorsten

    2017-01-01

    The excess of highly siderophile elements in the Earth’s mantle is thought to reflect the addition of primitive meteoritic material after core formation ceased. This ‘late veneer’ either comprises material remaining in the terrestrial planet region after the main stages of the Earth’s accretion, or derives from more distant asteroidal or cometary sources. Distinguishing between these disparate origins is important because a late veneer consisting of carbonaceous chondrite-like asteroids or comets could be the principal source of the Earth’s volatiles and water. Until now, however, a ‘genetic’ link between the late veneer and such volatile-rich materials has not been established or ruled out. Such genetic links can be determined using ruthenium (Ru) isotopes, because the Ru in the Earth’s mantle predominantly derives from the late veneer, and because meteorites exhibit Ru isotope variations arising from the heterogeneous distribution of stellar-derived dust. Although Ru isotopic data and the correlation of Ru and molybdenum (Mo) isotope anomalies in meteorites were previously used to argue that the late veneer derives from the same type of inner Solar System material as do Earth’s main building blocks, the Ru isotopic composition of carbonaceous chondrites has not been determined sufficiently well to rule them out as a source of the late veneer. Here we show that all chondrites, including carbonaceous chondrites, have Ru isotopic compositions distinct from that of the Earth’s mantle. The Ru isotope anomalies increase from enstatite to ordinary to carbonaceous chondrites, demonstrating that material formed at greater heliocentric distance contains larger Ru isotope anomalies. Therefore, these data refute an outer Solar System origin for the late veneer and imply that the late veneer was not the primary source of volatiles and water on the Earth.

  6. In vitro evaluation of fracture strength of zirconia restoration veneered with various ceramic materials

    PubMed Central

    Choi, Yu-Sung; Lee, Jai-Bong; Han, Jung-Suk; Yeo, In-Sung

    2012-01-01

    PURPOSE Fracture of the veneering material of zirconia restorations frequently occurs in clinical situations. The purpose of this in vitro study was to compare the fracture strengths of zirconia crowns veneered with various ceramic materials by various techniques. MATERIALS AND METHODS A 1.2 mm, 360° chamfer preparation and occlusal reduction of 2 mm were performed on a first mandibular molar, and 45 model dies were fabricated in a titanium alloy by CAD/CAM system. Forty-five zirconia copings were fabricated and divided into three groups. In the first group (LT) zirconia copings were veneered with feldspathic porcelain by the layering technique. In the second group (HT) the glass ceramic was heat-pressed on the zirconia coping, and for the third group (ST) a CAD/CAM-fabricated high-strength anatomically shaped veneering cap was sintered onto the zirconia coping. All crowns were cemented onto their titanium dies with Rely X™ Unicem (3M ESPE) and loaded with a universal testing machine (Instron 5583) until failure. The mean fracture values were compared by an one-way ANOVA and a multiple comparison post-hoc test (α=0.05). Scanning electron microscope was used to investigate the fractured interface. RESULTS Mean fracture load and standard deviation was 4263.8±1110.8 N for Group LT, 5070.8±1016.4 for Group HT and 6242.0±1759.5 N for Group ST. The values of Group ST were significantly higher than those of the other groups. CONCLUSION Zirconia crowns veneered with CAD/CAM generated glass ceramics by the sintering technique are superior to those veneered with feldspathic porcelain by the layering technique or veneered with glass ceramics by the heat-pressing technique in terms of fracture strength. PMID:22977725

  7. Effects of different application durations of scanning laser method on debonding strength of laminate veneers.

    PubMed

    Oztoprak, Mehmet Oguz; Tozlu, Murat; Iseri, Ufuk; Ulkur, Feyza; Arun, Tulin

    2012-07-01

    Porcelain laminate veneers as esthetic and minimally invasive restorations are being used as an alternative to full veneer crowns. However, the removal of porcelain veneers that have failed may be an uncomfortable and time-consuming procedure because of the high bond strength between the porcelain laminate veneers and the tooth surface. The purpose of this study was to prepare a simple and reliable method for porcelain laminate veneer debonding by using an Er:YAG laser with the scanning method and to determine the amount of lasing time required. Eighty cylindrical specimens with a thickness of 0.7 mm and a diameter of 5 mm were fabricated from Empress II ceramic material. They were cemented on the labial surface of extracted bovine mandibular incisors using Variolink II (Ivoclar Vivadent AG, Schaan, Liechtenstein) and light cured for 40 s. The specimens were randomly divided into four groups of 20. The first group was assigned as the control group and no laser application was performed. The Er:YAG laser was applied on each specimen in the other three study groups for 3, 6, and 9 s by using the scanning method. One second after the lasing, a mechanical force was applied to remove the laminate veneers by using an Instron Universal Testing machine. Results of this study exhibited statistically significant differences between the control group and the three study groups. Intergroup comparison of shear bond strengths of the three study groups showed a statistically significant difference (p = 0.0001). This study showed that all three application times of Er-YAG laser were effective for debonding ceramic laminate veneers by softening the adhesive resin.

  8. The effect of ceramic thickness and resin cement shades on the color matching of ceramic veneers in discolored teeth.

    PubMed

    Xing, Wenzhong; Chen, Xiaodong; Ren, Dafei; Zhan, Kangru; Wang, Yining

    2017-01-10

    The objective of this study was to analyze the effects of ceramic material thickness and resin cement shade on the color matching of ceramic veneers at the gray tooth structures. Seventy-two artificial maxillary right central incisor teeth (C2 shade) were prepared according to veneer tooth preparation in practice. Ceramic materials (LT, A2 shade, IPS e.max Press) were selected to fabricate the 0.50- and 0.75-mm thick veneers at the body region. The ceramic veneer specimens were bonded to the artificial teeth by the 6 shades of resin cements (Variolink Veneer: shades of HV+3, LV-2, LV-3; and RelyX(TM) Veneer: shades of WO, TR, A3). A clinical spectrophotometer (Crystaleye, Olympus) was used to measure the color parameters. The color differences (ΔE values) of ceramic veneers and A2 shade tab (Vitapan Classical, Vita) and C* ab values were calculated. The results of three-way ANOVA indicated that the ΔE values of ceramic veneer and A2 shade tab were significantly different in the thickness of ceramic materials, shades of resin cements, and measuring regions (p < 0.001). There were significant differences in 0.50-mm-thick ceramic veneers that exhibited higher ΔE values compared with veneers that were 0.75-mm thick. Tukey's HSD test showed that the average ΔE values in body region were significantly smaller than that in cervical and incisal regions. The color matching of ceramic veneers was significantly influenced not only by the ceramic thickness and the resin cement shades but also the tooth regions.

  9. Dental Hygienist.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Center on Education and Training for Employment.

    This document, which is designed for use in developing a tech prep competency profile for the occupation of dental hygienist, lists technical competencies and competency builders for 13 units pertinent to the health technologies cluster in general and 9 units specific to the occupation of dental hygienist. The following skill areas are covered in…

  10. Influence of Heat Treatment and Veneering on the Storage Modulus and Surface of Zirconia Ceramic

    PubMed Central

    Siavikis, Georgius; Behr, Michael; van der Zel, Jef M; Feilzer, Albert J; Rosentritt, Martin

    2011-01-01

    Objectives: Glass-ceramic veneered zirconia is used for the application as fixed partial dentures. The aim of this investigation was to evaluate whether the heat treatment during veneering, the application of glass-ceramic for veneering or long term storage has an influence on the storage modulus of zirconia. Methods: Zirconia bars (Cercon, DeguDent, G; 0.5x2x20 mm) were fabricated and treated according to veneering conditions. Besides heating regimes between 680°C and 1000°C (liner bake and annealing), sandblasting (Al2O3) or steam cleaning were used. The bars were investigated after 90 days storage in water and acid. For investigating the influence of veneering, the bars were veneered in press- or layer technique. Dynamic mechanical analysis (DMA) in a three-point-bending design was performed to determine the storage modulus between 25°C and 200°C at a frequency of 1.66 Hz. All specimens were loaded on top and bottom (treatment on pressure or tensile stress side). Scanning electron microscopy (SEM) was used for evaluating the superficial changes of the zirconia surface due to treatment. Statistical analysis was performed using Mann Whitney U-test (α=0.05). Results: Sintered zirconia provided a storage modulus E’ of 215 (203/219) GPa and tan δ of 0.04 at 110°C. A 10%-decrease of E’ was found up to 180°C. The superficial appearance changed due to heating regime. Sandblasting reduced E’ to 213 GPa, heating influenced E’ between 205 GPa (liner bake 1) and 222 GPa (dentin bake 1). Steam cleaning, annealing and storage changed E’ between 4 GPa and 22 GPa, depending on the side of loading. After veneering, strong E’-reduction was found down to 84 GPa and 125 GPa. Conclusions: Veneering of zirconia with glass-ceramic in contrast to heat treating during veneering procedure had a strong influence on the modulus. The application of the glass-ceramic caused a stronger decrease of the storage modulus. PMID:21494388

  11. Dental Implants.

    PubMed

    Zohrabian, Vahe M; Sonick, Michael; Hwang, Debby; Abrahams, James J

    2015-10-01

    Dental implants restore function to near normal in partially or completely edentulous patients. A root-form implant is the most frequently used type of dental implant today. The basis for dental implants is osseointegration, in which osteoblasts grow and directly integrate with the surface of titanium posts surgically embedded into the jaw. Radiologic assessment is critical in the preoperative evaluation of the dental implant patient, as the exact height, width, and contour of the alveolar ridge must be determined. Moreover, the precise locations of the maxillary sinuses and mandibular canals, as well as their relationships to the site of implant surgery must be ascertained. As such, radiologists must be familiar with implant design and surgical placement, as well as augmentation procedures utilized in those patients with insufficient bone in the maxilla and mandible to support dental implants.

  12. Marginal adaptation of Spinell InCeram and feldspathic porcelain laminate veneers

    PubMed Central

    Ghaffari, Tahereh; Hamedi-Rad, Fahimeh; Fakhrzadeh, Vahid

    2016-01-01

    Background: This in vitro study investigated the marginal fit of two porcelain laminate veneers to help the selection of more accurate veneers in discolored teeth. Materials and Methods: Thirty impressions of metal master die created from the prepared labial surface of an acrylic maxillary central incisor were made and poured with Type IV stone. The dies were distributed into test groups (n = 15) for the construction of DuCeram and InCeram laminate veneers. An image-analysis program was used to measure the gap between the veneers and the master die at the labial, lingual, and proximal margins. Statistical analysis was performed with repeated measures ANOVA. Independent t-test was used to compare the mean values between the two groups. Values of P < 0.05 were judged to be significant. Results: Differences between marginal fit of two groups were significant (P < 0.001). The overall mean marginal gap values (μm) for InCeram and DuCeram were, respectively, 114.4 ± 40.81 and 282.3 ± 82.82. Independent t-test revealed significant differences between the marginal gaps of two materials at different predetermined points. Conclusion: Within the limitations of this study, the marginal gap in InCeram laminate veneer was within the clinically acceptable standard set at 120 μm. PMID:27274344

  13. Treatment of natural wood veneers with nano-oxides to improve their fire behaviour

    NASA Astrophysics Data System (ADS)

    Francés Bueno, A. B.; Navarro Bañón, M. V.; Martínez de Morentín, L.; Moratalla García, J.

    2014-08-01

    Conventional flame retardants used to improve fire behaviour of wood based materials are commonly based on halogenated and/or nitrogenated chemicals. These chemicals are toxic and can harm the environment and human health. Some works describe the incorporation of nanomaterials to the polymeric systems to improve their fire behaviour. The aim of this work was to analyze the effect of several treatments based on the use of nanomaterials on the properties of natural wood veneers and mainly on their fire behaviour. Firstly, several modes for treating pine veneers (immersion, spraying and impregnation) were evaluated using a commercial flame retardant to select the most effective treatment. The treatment selected as the most effective was immersion in a bath of flame retarding agent for 30 minutes at standard conditions. Afterward, pine veneers were treated by immersion in aqueous dispersions which contained 3wt% of the following nanoparticles: SiO2, TiO2 and ZrO2, respectively. The effect of each treatment on the properties of veneers was analyzed. The results obtained showed that the treatment based on the use of 3wt% SiO2 aqueous dispersion was the most effective to improve the fire behaviour of pine veneers.

  14. Nonlinear visco-elastic finite element analysis of different porcelain veneers configuration.

    PubMed

    Sorrentino, Roberto; Apicella, Davide; Riccio, Carlo; Gherlone, Enrico; Zarone, Fernando; Aversa, Raffaella; Garcia-Godoy, Franklin; Ferrari, Marco; Apicella, Antonio

    2009-11-01

    This study is aimed at evaluating the biomechanical behavior of feldspathic versus alumina porcelain veneers. A 3D numerical model of a maxillary central incisor, with the periodontal ligament (PDL) and the alveolar bone was generated. Such model was made up of four main volumes: dentin, enamel, cement layer and veneer. Incisors restored with alumina and feldspathic porcelain veneers were compared with a natural sound tooth (control). Enamel, cementum, cancellous and cortical bone were considered as isotropic elastic materials; on the contrary, the tubular structure of dentin was designed as elastic orthotropic. The nonlinear visco-elatic behavior of the PDL was considered. The veneer volumes were coupled with alumina and feldspathic porcelain mechanical properties. The adhesive layers were modeled in the FE environment using spring elements. A 50N load applied at 60 degrees angle with tooth longitudinal axis was applied and validated. Compressive stresses were concentrated on the external surface of the buccal side of the veneer close to the incisal margin; such phenomenon was more evident in the presence of alumina. Tensile stresses were negligible when compared to compressive ones. Alumina and feldspathic ceramic were characterized by a different biomechanical behavior in terms of elastic deformations and stress distributions. The ultimate strength of both materials was not overcome in the performed analysis.

  15. Thoracic complications associated with utilization of the air turbine dental drill.

    PubMed

    Kost, M

    1996-06-01

    Thoracic complications associated with the use of the high-speed air turbine dental drill have been reported sporadically in the anesthesia literature. This case report documents the potential sequelae associated with air entrainment from utilization of the high-speed air turbine dental drill in general dentistry. Signs and symptoms of air entrainment include chest fullness, periorbital and facial edema, and crepitus. Prompt recognition of this phenomena is essential because of potential airway obstruction and additional complications, as the infused air dissects through the fascial planes. Cardiovascular collapse, associated with the development of venous air embolism, has also been reported as a life-threatening complication associated with the high-speed air turbine dental drill. This is a case report of a patient who developed pneumomediastinum while receiving dental preparatory treatment for multiple crowns, veneers, and impressions.

  16. Zirconia-based dental crown to support a removable partial denture: a three-dimensional finite element analysis using contact elements and micro-CT data.

    PubMed

    Rocha, Eduardo Passos; Anchieta, Rodolfo Bruniera; de Almeida, Erika Oliveira; Freitas, Amilcar Chagas; Martini, Ana Paula; Sotto-Maior, Bruno Sales; Luersen, Marco Antonio; Ko, Ching Chang

    2015-01-01

    Veneer fracture is the most common complication in zirconia-based restorations. The aim of this study was to evaluate the mechanical behavior of a zirconia-based crown in a lower canine tooth supporting removable partial denture (RPD) prosthesis, varying the bond quality of the veneer/coping interface. Microtomography (μCT) data of an extracted left lower canine were used to build the finite element model (M) varying the core material (gold core - MAu; zirconia core - MZi) and the quality of the veneer/core interface (complete bonded - MZi; incomplete bonded - MZi-NL). The incomplete bonding condition was only applied for zirconia coping by using contact elements (Target/Contact) with 0.3 frictional coefficients. Stress fields were obtained using Ansys Workbench 10.0. The loading condition (L = 1 N) was vertically applied at the base of the RPD prosthesis metallic support towards the dental apex. Maximum principal (σmax) and von Mises equivalent (σvM) stresses were obtained. The σmax (MPa) for the bonded condition was similar between gold and zirconia cores (MAu, 0.42; MZi, 0.40). The incomplete bonded condition (MZi-NL) raised σmax in the veneer up to 800% (3.23 MPa) in contrast to the bonded condition. The peak of σvM increased up to 270% in the MZi-NL. The incomplete bond condition increasing the stress in the veneer/zirconia interface.

  17. Dental OCT

    NASA Astrophysics Data System (ADS)

    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.

  18. Spectrophotometric Study of the Effect of Luting Agents on the Resultant Shade of Ceramic Veneers: An Invitro Study

    PubMed Central

    Kale, Yogesh; Pustake, Swati; Bijjaragi, Shobha; Pustake, Bhushan

    2015-01-01

    Introduction Dentistry has found practically the best available aesthetic answer, is ceramic restoration. There are various factors that contribute to the success of ceramic veneers, like colour of underlying tooth, thickness if ceramics and the type of underlying luting cement. Shade selection and matching remains still challenge, however the shade of luting agent used for cementation of veneers produces a change in resultant shade of veneers. Aim To compare and analyze the spectrophotometric effect of opaque and transparent luting agent on resultant shade of ceramic veneers made of 2L1.5 shade (Vitapan 3D-Masters) and B2 shade (Vitapan Classic). Materials and Methods Out of 15 ceramic veneers of 2L1.5 shade (VITAPAN 3D- Master), seven teeth cemented with opaque cement and eight teeth with transparent cement shade of dual cure resin cement (Variolink IITM). Out of 10 ceramic veneers of B2 shade (VITAPAN Classic), five teeth were cemented with opaque cement and other five teeth with transparent cement shade of dual cure resin cement (Variolink IITM). Spectrophotometric (Macbeth U.S.A.) analysis of all ceramic veneer crowns done with optiview software and readings were recorded in Commission Internationale de I’ Eclairge {CIELAB} system and dE value was calculated. Statistical Analysis Statistical analysis was done by using Paired t-test. Results Spectrophotometric analysis of all the veneers cemented with opaque luting agent were lighter in shade due to significant change in dL value. Veneers cemented with transparent luting agent were darker in shade due to significant change in the dL value. Conclusion Opaque luting agent gives lighter shade and transparent luting agent gives darker shade to ceramic veneers fabricated with 2L1.5 and B2 shades. PMID:26501014

  19. How will surface treatments affect the translucency of porcelain laminate veneers?

    PubMed Central

    Turgut, Sedanur; Ayaz, Elif Aydogan; Korkmaz, Fatih Mehmet; Ulusoy, Kıvanç Utku; Bagis, Yildirim Hakan

    2014-01-01

    PURPOSE The purpose of this study was to evaluate whether surface treatments affect the translucency of laminate veneers with different shades and thicknesses. MATERIALS AND METHODS A total of 224 disc-shaped ceramic veneers were prepared from A1, A3, HT (High Translucent) and HO (High Opaque) shades of IPS e.max Press (Ivoclar Vivadent) with 0.5 mm and 1.0 mm thicknesses. The ceramics were divided into four groups for surface treatments. Group C: no surface treatments; Group HF: etched with hydrofluoric acid; Group SB: sandblasted with 50-µm Al2O3; and Group L; irradiated with an Er;YAG laser. A translucent shade of resin cement (Rely X Veneer, 3M ESPE) was chosen for cementation. The color values of the veneers were measured with a colorimeter and translucency parameter (TP) values were calculated. A three-way ANOVA with interactions for TP values was performed and Bonferroni tests were used when appropriate (α=0.05). RESULTS There were significant interactions between the surface treatments, ceramic shades and thicknesses (P=.001). For the 0.5-mm-thick specimens there were significant differences after the SB and L treatments. There was no significant difference between the HF and C treatments for any shades or thicknesses (P>.05). For the 1-mm-thick ceramics, there was only a significant difference between the L and C treatments for the HT shade ceramics (P=.01). There were also significant differences between the SB and C treatments except not for the HO shades (P=.768). CONCLUSION The SB and L treatments caused laminate veneers to become more opaque; however, HF treatment did not affect the TP values. When the laminate veneers were thinner, both the shade of the ceramic and the SB and laser treatments had a greater effect on the TP values. PMID:24605200

  20. Kubelka-Munk reflectance theory applied to porcelain veneer systems using a colorimeter.

    PubMed

    Davis, B K; Johnston, W M; Saba, R F

    1994-01-01

    The purpose of this study was to demonstrate the ability of Kubelka-Munk reflectance theory to predict color parameters of veneer porcelain on various backings using colorimetric measurements. Tristimulus absorption and scattering coefficients were used to predict the respective tristimulus reflectance values of A1, D3, and translucent porcelain samples after they had been bonded to light and dark substrates using universal, opaque, and untinted shades of bonding resin. Observed and predicted reflectance values exhibited high correlation (r2 > or = 0.93 for each porcelain shade). Kubelka-Munk theory offers an accurate prediction for the resultant colorimetric reflectance parameters of veneer porcelain bonded to variously colored backings.

  1. Restoration of primary canines with porcelain laminate veneers: a clinical report.

    PubMed

    Beyabanaki, Elaheh; Alikhasi, Marzieh

    2014-09-01

    This article describes treatment of a young adult patient with porcelain laminate veneers for restoring unaesthetic maxillary anterior teeth with two retained primary canines. The patient had experienced an approximately two-year orthodontic treatment and had received both fixed and removable retainers for the upper arch. The patient could not afford implant supported restorations for his missing premolar teeth and was not pleased by the appearance of his smile. Using porcelain laminate veneers is a proper treatment option that could be taken into consideration in these situations.

  2. Some important physical properties of laminated veneer lumber (Lvl) made from oriental beech and Lombardy poplar

    NASA Astrophysics Data System (ADS)

    Kılıç, Murat

    2012-09-01

    This study examined some physical characteristics of laminated veneer lumber (LVL) obtained in different compositions from cut veneers of Oriental beech (Fagus Orientalis Lipsky) and Lombardy poplar (Populus nigra) with thicknesses of 4 mm and 5 mm. Five each beech and poplar trees were felled with this objective. The PVAc (Kleiberit 303) and PU (Bizon Timber PU-Max Express) types of adhesive were used in lamination. The air-dry and oven dry densities, cell wall density and porosity, the value of volume density, shrinkage in a tangential and radial direction and volume swelling amounts were determined by preparing the specimens in accordance with the standards.

  3. Registered Dental Hygienists as Dental Students.

    ERIC Educational Resources Information Center

    Arnold, Janet; Shugars, Daniel A.

    1985-01-01

    Surveys conducted to (1) investigate why dental hygienists choose to become dentists, (2) evaluate their success in dental school, (3) assess the experience of those who had entered dental school, and (4) gauge the level of interest among dental hygienists in applying to dental school are discussed. (Author/MLW)

  4. A fractographic study of clinically retrieved zirconia–ceramic and metal–ceramic fixed dental prostheses

    PubMed Central

    Pang, Zhen; Chughtai, Asima; Sailer, Irena; Zhang, Yu

    2015-01-01

    Objectives A recent 3-year randomized controlled trial (RCT) of tooth supported three- to five-unit zirconia–ceramic and metal–ceramic posterior fixed dental prostheses (FDPs) revealed that veneer chipping and fracture in zirconia–ceramic systems occurred more frequently than those in metal–ceramic systems [1]. This study seeks to elucidate the underlying mechanisms responsible for the fracture phenomena observed in this RCT using a descriptive fractographic analysis. Methods Vinyl-polysiloxane impressions of 12 zirconia–ceramic and 6 metal–ceramic FDPs with veneer fractures were taken from the patients at the end of a mean observation of 40.3 ± 2.8 months. Epoxy replicas were produced from these impressions [1]. All replicas were gold coated, and inspected under the optical microscope and scanning electron microscope (SEM) for descriptive fractography. Results Among the 12 zirconia–ceramic FDPs, 2 had small chippings, 9 had large chippings, and 1 exhibited delamination. Out of 6 metal–ceramic FDPs, 5 had small chippings and 1 had large chipping. Descriptive fractographic analysis based on SEM observations revealed that fracture initiated from the wear facet at the occlusal surface in all cases, irrespective of the type of restoration. Significance Zirconia–ceramic and metal–ceramic FDPs all fractured from microcracks that emanated from occlusal wear facets. The relatively low fracture toughness and high residual tensile stress in porcelain veneer of zirconia restorations may contribute to the higher chipping rate and larger chip size in zirconia–ceramic FDPs relative to their metal–ceramic counterparts. The low veneer/core interfacial fracture energy of porcelain-veneered zirconia may result in the occurrence of delamination in zirconia–ceramic FDPs. PMID:26233469

  5. Two-body wear of dental porcelain and substructure oxide ceramics.

    PubMed

    Rosentritt, Martin; Preis, Verena; Behr, Michael; Hahnel, Sebastian; Handel, Gerhard; Kolbeck, Carola

    2012-06-01

    The aim of this in vitro study was to investigate the two-body wear of different ceramics. Two-body wear tests were performed in a chewing simulator with steatite and enamel antagonists, respectively. Specimens were loaded in a pin-on-block design with a vertical load of 50 N for 1.2 × 10(5) cycles; (f = 1.6 Hz; lateral movement, 1 mm; mouth opening: 2 mm). Human enamel was used as a reference. Three zirconia ceramics, three veneering porcelains, two glass-infiltrated and one lithium disilicate ceramic were investigated. Veneering and lithium disilicate ceramics were glazed before testing. Surface roughness Ra (SP6, Perthen-Feinprüf, G) and wear depth were determined using a 3D scanner (Laserscan 3D, Willytec, G). SEM (Quanta FEG 400, FEI, USA) pictures of the worn specimens and antagonists were made for evaluating wear performance. Veneering porcelain provided wear traces between 71.2 and 124.1 μm (enamel antagonist) and 117.4 and 274.1 μm (steatite). Wear of the steatite antagonists varied between 0.618 and 2.85 mm². No wear was found for zirconia and glass-infiltrated substructure ceramics. Also, no wear was found for the corresponding antagonists. Wear of specimens and antagonists was strongly material dependent. No visible wear was found on zirconia and glass-infiltrated ceramics. Porcelain and lithium disilicate ceramic showed a comparable or lower wear than the enamel reference. Antagonist wear was found to be lower when specimens were made of substructure oxide ceramics instead of veneering porcelain. From the point of wear testing, zirconia may be used for the fabrication of fixed dental prosthesis without veneering.

  6. Dental sealants

    MedlinePlus

    ... few quick steps. There is no drilling or scraping of the molars. Your dentist will: Clean the ... Dental sealants. Updated October 19, 2016. ADA.org Web site. www.ada.org/en/member-center/oral- ...

  7. Dental Sealants

    MedlinePlus

    ... form does not collect any actual information. External Web Site Policy This graphic notice ( ) means that you are ... the link. Home Contact Us Viewers and Players Site Map FOIA Web Policies Privacy Policy National Institute of Dental and ...

  8. 75 FR 16511 - Pentron Clinical Technologies, a Wholly-Owned Subsidiary of Kerr Dental/Sybron Dental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-01

    ... such as dental prosthetics, dental composites, dental impressions, dental adhesives, and other dental... prosthetics, dental composites, dental impressions, dental adhesives, and other dental materials to...

  9. Dental Emergencies

    PubMed Central

    Symington, J.M.

    1988-01-01

    Patients with dental emergencies sometimes present to their physician. This article outlines the role of the physician in the management of dental patients who have suffered traumatic injuries, postoperative hemorrhage, pain, and infection. It deals with those difficulties for which the physician may easily prescribe treatment and outlines the treatment that would be undertaken by a dentist who receives such a patient on referral. PMID:21253249

  10. Fractographic Analysis of a Dental Zirconia Framework: a Case Study on Design Issues

    PubMed Central

    Lohbauer, Ulrich; Amberger, Gudrun; Quinn, George D.; Scherrer, Susanne S.

    2011-01-01

    Fractographic analysis of clinically failed dental ceramics can provide insights as to the failure origin and related mechanisms. One anterior 6-unit all-ceramic zirconia fixed partial denture (FPD) (Cercon®) has been clinically recovered and examined using qualitative fractography. The purpose was to identify the fracture origin and to state the reasons for failure. The recovered parts of the zirconia FPD were microscopically examined to identify classic fractographic patterns such as arrest lines, hackle, twist hackle and wake hackle. The direction of crack propagation was mapped and interpreted back to the origin of failure at the interface of the occlusalpalatal tip of the core and the veneering ceramic. An inappropriate core drop design favoring localized stress concentration combined with a pore cluster in the veneering ceramic at the core tip interface were the reasons for this premature through-the-core thickness failure. PMID:20826369

  11. The Effect of Veneer Layers on the Bending Shear Strength and Delamination of Laminated Veneer Lumber (LVL) from Oil Palm Trunk (OPT)

    NASA Astrophysics Data System (ADS)

    Jamaludin, M. A.; Nordin, K.; Bahari, S. A.; Ahmad, M.

    2010-03-01

    The aim of this study was to evaluate the effects of the number of veneer layers on the bending shear strength and delamination of Laminated Veneer Lumber (LVL) from oil palm trunk (OPT). Five (5), Six (6) and Seven (7) veneer layers of OPT LVL were manufactured. The dimension of the boards was 45 cm by 45 cm by 1.9 cm. The boards were hot pressed for 13 minutes at a pressure of 31 kgf per m2. Urea formaldehyde (UF) supplied by a local adhesive manufacturer was used as the binder for the boards. The bending shear tests consisted of the edgewise and flatwise tests, whereas the delamination test consisted of the cold and hot water boil tests. The preparation of the test specimens and tests set-up was in accordance to the Japanese Standards, JAS-1991 [1]. Six replications were used for each test. The results were analyzed by Analysis of Variance (ANOVA) using the Duncan's Multiple Range Test to test for significant differences. The results indicated that as the number of layers increased the strength also increased. All the boards passed the standard. The difference in strength between the different types of samples was significant at 95 percent confidence level. Bending shear failures were primarily in the veneers. It is possible to use the boards as light weight interior building and furniture components. Over the years, the supply of quality timber resources from the natural forest has decrease as the wood-based industry experienced rapid growth. The supply of rubberwood for the furniture industry is also decreasing as a result of increase latex price. Accordingly, OPT LVL can be an alternative or supplementary raw material for the wood-based industry.

  12. Fracture resistance of porcelain veneered zirconia crowns with exposed lingual zirconia for anterior teeth after thermal cycling: An in vitro study

    PubMed Central

    Amir Rad, Fatemeh A.; Succaria, Faysal G.; Morgano, Steven M.

    2015-01-01

    Statement of problem In some clinical conditions minimally invasive complete crown tooth preparations are indicated. This is especially true when gross removal of tooth structure would weaken the remaining tooth or violate the vitality of the dental pulp. Objective The purpose of this study was to investigate the influence of (1) exposed lingual zirconia with veneered zirconia crowns, and (2) reduced lingual thickness of monolithic lithium disilicate crowns on the fracture resistance of the crowns after cyclic loading. Metal-ceramic crowns with exposed lingual metal served as controls. Materials and methods Twenty-four maxillary central incisor crowns were fabricated in identical shape on metal testing dies in 3 groups: metal-ceramic crowns (MC, n = 8), veneered zirconia crowns (VZ, n = 8), and monolithic lithium disilicate crowns (MO, n = 8). A conservative preparation design with 0.75 mm lingual clearance was used for each crown system. All crowns were cemented to their corresponding crown preparations with self-adhesive resin cement (Multilink Automix). The crowns were subjected to 1000 cycles of thermal cycling, then cyclic loading of 111 N by means of a stainless steel ball, and 50,000 cycles of loading were applied for the fatigue test. Fatigue loading was followed by a continuously increasing compressive load, at a crosshead speed of 1 mm/min until failure. The compressive load (N) required to cause failure was recorded. Means were calculated and analyzed with one-way ANOVA and the Tukey HSD test (α = .05). Results There was a significant difference between MO vs. MC (P = .0001), MO vs. VZ (P = .0001), and VZ vs. MC (P = .012). Conclusions There was a significant difference in the mean fracture resistance of MC, VZ, and MO crowns in this in vitro study. The MC group recorded the highest mean fracture strength. PMID:26082571

  13. Preformed resin-veneered stainless steel crowns for restoration of primary incisors.

    PubMed

    Croll, T P; Helpin, M L

    1996-05-01

    Stainless steel crown forms with bonded resin veneers for primary incisors are commercially available to dentists. This type of preveneered crown was developed to serve as a convenient, durable, reliable, and esthetic solution to the difficult challenge of restoring severely carious primary incisors. This article describes preveneered crowns, reviews their advantages and disadvantages, and details a technique for placement of such restorations.

  14. Veneers, rinds, and fracture fills: Relatively late alteration of sedimentary rocks at Meridiani Planum, Mars

    USGS Publications Warehouse

    Knoll, A.H.; Jolliff, B.L.; Farrand, W. H.; Bell, J.F.; Clark, B. C.; Gellert, Ralf; Golombek, M.P.; Grotzinger, J.P.; Herkenhoff, K. E.; Johson, J.R.; McLennam, S.M.; Morris, Robert; Squyres, S. W.; Sullivan, R.; Tosca, N.J.; Yen, A.; Learner, Z.

    2008-01-01

    Veneers and thicker rinds that coat outcrop surfaces and partially cemented fracture fills formed perpendicular to bedding document relatively late stage alteration of ancient sedimentary rocks at Meridiani Planum, Mars. The chemistry of submillimeter thick, buff-colored veneers reflects multiple processes at work since the establishment of the current plains surface. Veneer composition is dominated by the mixing of silicate-rich dust and sulfate-rich outcrop surface, but it has also been influenced by mineral precipitation, including NaCl, and possibly by limited physical or chemical weathering of sulfate minerals. Competing processes of chemical alteration (perhaps mediated by thin films of water or water vapor beneath blanketing soils) and sandblasting of exposed outcrop surfaces determine the current distribution of veneers. Dark-toned rinds several millimeters thick reflect more extensive surface alteration but also indicate combined dust admixture, halite precipitation, and possible minor sulfate removal. Cemented fracture fills that are differentially resistant to erosion occur along the margins of linear fracture systems possibly related to impact. These appear to reflect limited groundwater activity along the margins of fractures, cementing mechanically introduced fill derived principally from outcrop rocks. The limited thickness and spatial distribution of these three features suggest that aqueous activity has been rare and transient or has operated at exceedingly low rates during the protracted interval since outcropping Meridiani strata were exposed on the plains surface. Copyright 2008 by the American Geophysical Union.

  15. ESTIMATING THE SIZE OF LATE VENEER IMPACTORS FROM IMPACT-INDUCED MIXING ON MERCURY

    SciTech Connect

    Rivera-Valentin, E. G.; Barr, A. C.

    2014-02-10

    Late accretion of a ''veneer'' of compositionally diverse planetesimals may introduce chemical heterogeneity in the mantles of the terrestrial planets. The size of the late veneer objects is an important control on the angular momenta, eccentricities, and inclinations of the terrestrial planets, but current estimates range from meter-scale bodies to objects with diameters of thousands of kilometers. We use a three-dimensional global Monte Carlo model of impact cratering, excavation, and ejecta blanket formation to show that evidence of mantle heterogeneity can be preserved within ejecta blankets of mantle-exhuming impacts on terrestrial planets. Compositionally distinct provinces implanted at the time of the late veneer are most likely to be preserved in bodies whose subsequent geodynamical evolution is limited. Mercury may have avoided intensive mixing by solid-state convection during much of its history. Its subsequent bombardment may have then excavated evidence of primordial mantle heterogeneity introduced by the late veneer. Simple geometric arguments can predict the amount of mantle material in the ejecta blanket of mantle-exhuming impacts, and deviations in composition relative to geometric predictions can constrain the length-scale of chemical heterogeneities in the subsurface. A marked change in the relationship between mantle and ejecta composition occurs when chemically distinct provinces are ∼250 km in diameter; thus, evidence of bombardment by thousand-kilometer-sized objects should be readily apparent from the variation in compositions of ejecta blankets in Mercury's ancient cratered terrains.

  16. Role of indenter material and size in veneer failure of brittle layer structures.

    PubMed

    Bhowmick, Sanjit; Meléndez-Martínez, Juan José; Hermann, Ilja; Zhang, Yu; Lawn, Brian R

    2007-07-01

    The roles of indenter material and size in the failure of brittle veneer layers in all-ceramic crown-like structures are studied. Glass veneer layers 1 mm thick bonded to alumina layers 0.5 mm thick on polycarbonate bases (representative of porcelain/ceramic-core/dentin) are subject to cyclic contact loading with spherical indenters in water (representative of occlusal biting environment). Two indenter materials-glass and tungsten carbide-and three indenter radii-1.6, 5.0, and 12.5 mm-are investigated in the tests. A video camera is used to follow the near-contact initiation and subsequent downward propagation of cone cracks through the veneer layer to the core interface, at which point the specimen is considered to have failed. Both indenter material and indenter radius have some effect on the critical loads to initiate cracks within the local Hertzian contact field, but the influence of modulus is weaker. The critical loads to take the veneer to failure are relatively insensitive to either of these indenter variables, since the bulk of the cone crack propagation takes place in the contact far field. Clinical implications of the results are considered, including the issue of single-cycle overload versus low-load cyclic fatigue and changes in fracture mode with loading conditions.

  17. 40 CFR 63.2266 - Initial compliance demonstration for a veneer redryer.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Initial compliance demonstration for a veneer redryer. 63.2266 Section 63.2266 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... CATEGORIES National Emission Standards for Hazardous Air Pollutants: Plywood and Composite Wood...

  18. 40 CFR 63.2266 - Initial compliance demonstration for a veneer redryer.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 13 2014-07-01 2014-07-01 false Initial compliance demonstration for a veneer redryer. 63.2266 Section 63.2266 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants: Plywood and Composite...

  19. 40 CFR 63.2265 - Initial compliance demonstration for a softwood veneer dryer.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 13 2014-07-01 2014-07-01 false Initial compliance demonstration for a softwood veneer dryer. 63.2265 Section 63.2265 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants: Plywood and Composite...

  20. 40 CFR 63.2266 - Initial compliance demonstration for a veneer redryer.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 13 2012-07-01 2012-07-01 false Initial compliance demonstration for a veneer redryer. 63.2266 Section 63.2266 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants: Plywood and Composite...

  1. 40 CFR 63.2264 - Initial compliance demonstration for a hardwood veneer dryer.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 13 2014-07-01 2014-07-01 false Initial compliance demonstration for a hardwood veneer dryer. 63.2264 Section 63.2264 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants: Plywood and Composite...

  2. 40 CFR 63.2265 - Initial compliance demonstration for a softwood veneer dryer.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Initial compliance demonstration for a softwood veneer dryer. 63.2265 Section 63.2265 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... CATEGORIES National Emission Standards for Hazardous Air Pollutants: Plywood and Composite Wood...

  3. 40 CFR 63.2265 - Initial compliance demonstration for a softwood veneer dryer.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 13 2012-07-01 2012-07-01 false Initial compliance demonstration for a softwood veneer dryer. 63.2265 Section 63.2265 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants: Plywood and Composite...

  4. 40 CFR 63.2264 - Initial compliance demonstration for a hardwood veneer dryer.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 13 2012-07-01 2012-07-01 false Initial compliance demonstration for a hardwood veneer dryer. 63.2264 Section 63.2264 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants: Plywood and Composite...

  5. 40 CFR 63.2264 - Initial compliance demonstration for a hardwood veneer dryer.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Initial compliance demonstration for a hardwood veneer dryer. 63.2264 Section 63.2264 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... CATEGORIES National Emission Standards for Hazardous Air Pollutants: Plywood and Composite Wood...

  6. Effect of Er:YAG laser on debonding strength of laminate veneers

    PubMed Central

    Iseri, Ufuk; Oztoprak, Mehmet Oguz; Ozkurt, Zeynep; Kazazoglu, Ender; Arun, Tulin

    2014-01-01

    Objective: The purpose of this study was to evaluate the debonding strength of laminate veneers after using erbium-doped: yttrium aluminium garnet (Er:YAG) laser. Materials and Methods: A total of 60 bovine mandibular incisor teeth were divided into two groups (n = 30). Cylindrical specimens (0.7 mm × 5 mm) were fabricated from Empress II ceramic. Then, they were cemented to incisors using dual-cured resin cement (Variolink II). In the first group, no laser application was performed. The Er:YAG laser was applied on each laminate veneer at the test group for 9 s by using the scanning method. Shear force to remove the laminate veneers were applied with universal testing machine at a crosshead speed of 1 mm/min. Results: Results of this study exhibited significant differences between the control (27.28 ± 2.24 MPa) and test group (3.44 ± 0.69 MPa) (P < 0.05). Conclusion: This study shows that application of Er:YAG laser decreased the bond strength of laminate veneers. PMID:24966747

  7. Veneers, rinds, and fracture fills: Relatively late alteration of sedimentary rocks at Meridiani Planum, Mars

    NASA Astrophysics Data System (ADS)

    Knoll, Andrew H.; Jolliff, Brad L.; Farrand, William H.; Bell, James F., III; Clark, Benton C.; Gellert, Ralf; Golombek, M. P.; Grotzinger, John P.; Herkenhoff, Kenneth E.; Johnson, Jeffrey R.; McLennan, Scott M.; Morris, Richard; Squyres, Steven W.; Sullivan, Robert; Tosca, Nicholas J.; Yen, Albert; Learner, Zoe

    2008-05-01

    Veneers and thicker rinds that coat outcrop surfaces and partially cemented fracture fills formed perpendicular to bedding document relatively late stage alteration of ancient sedimentary rocks at Meridiani Planum, Mars. The chemistry of submillimeter thick, buff-colored veneers reflects multiple processes at work since the establishment of the current plains surface. Veneer composition is dominated by the mixing of silicate-rich dust and sulfate-rich outcrop surface, but it has also been influenced by mineral precipitation, including NaCl, and possibly by limited physical or chemical weathering of sulfate minerals. Competing processes of chemical alteration (perhaps mediated by thin films of water or water vapor beneath blanketing soils) and sandblasting of exposed outcrop surfaces determine the current distribution of veneers. Dark-toned rinds several millimeters thick reflect more extensive surface alteration but also indicate combined dust admixture, halite precipitation, and possible minor sulfate removal. Cemented fracture fills that are differentially resistant to erosion occur along the margins of linear fracture systems possibly related to impact. These appear to reflect limited groundwater activity along the margins of fractures, cementing mechanically introduced fill derived principally from outcrop rocks. The limited thickness and spatial distribution of these three features suggest that aqueous activity has been rare and transient or has operated at exceedingly low rates during the protracted interval since outcropping Meridiani strata were exposed on the plains surface.

  8. Effect of colouring green stage zirconia on the adhesion of veneering ceramics with different thermal expansion coefficients.

    PubMed

    Aktas, Guliz; Sahin, Erdal; Vallittu, Pekka; Ozcan, Mutlu; Lassila, Lippo

    2013-12-01

    This study evaluated the adhesion of zirconia core ceramics with their corresponding veneering ceramics, having different thermal expansion coefficients (TECs), when zirconia ceramics were coloured at green stage. Zirconia blocks (N=240; 6 mm×7 mm×7 mm) were manufactured from two materials namely, ICE Zirconia (Group 1) and Prettau Zirconia (Group 2). In their green stage, they were randomly divided into two groups. Half of the specimens were coloured with colouring liquid (shade A2). Three different veneering ceramics with different TEC (ICE Ceramic, GC Initial Zr and IPS e.max Ceram) were fired on both coloured and non-coloured zirconia cores. Specimens of high noble alloys (Esteticor Plus) veneered with ceramic (VM 13) (n=16) acted as the control group. Core-veneer interface of the specimens were subjected to shear force in the Universal Testing Machine (0.5 mm⋅min(-1)). Neither the zirconia core material (P=0.318) nor colouring (P=0.188) significantly affected the results (three-way analysis of variance, Tukey's test). But the results were significantly affected by the veneering ceramic (P=0.000). Control group exhibited significantly higher mean bond strength values (45.7±8) MPa than all other tested groups ((27.1±4.1)-(39.7±4.7) and (27.4±5.6)-(35.9±4.7) MPa with and without colouring, respectively) (P<0.001). While in zirconia-veneer test groups, predominantly mixed type of failures were observed with the veneering ceramic covering <1/3 of the substrate surface, in the metal-ceramic group, veneering ceramic was left adhered >1/3 of the metal surface. Colouring zirconia did not impair adhesion of veneering ceramic, but veneering ceramic had a significant influence on the core-veneer adhesion. Metal-ceramic adhesion was more reliable than all zirconia-veneer ceramics tested.

  9. Effect of colouring green stage zirconia on the adhesion of veneering ceramics with different thermal expansion coefficients

    PubMed Central

    Aktas, Guliz; Sahin, Erdal; Vallittu, Pekka; Özcan, Mutlu; Lassila, Lippo

    2013-01-01

    This study evaluated the adhesion of zirconia core ceramics with their corresponding veneering ceramics, having different thermal expansion coefficients (TECs), when zirconia ceramics were coloured at green stage. Zirconia blocks (N=240; 6 mm×7 mm×7 mm) were manufactured from two materials namely, ICE Zirconia (Group 1) and Prettau Zirconia (Group 2). In their green stage, they were randomly divided into two groups. Half of the specimens were coloured with colouring liquid (shade A2). Three different veneering ceramics with different TEC (ICE Ceramic, GC Initial Zr and IPS e.max Ceram) were fired on both coloured and non-coloured zirconia cores. Specimens of high noble alloys (Esteticor Plus) veneered with ceramic (VM 13) (n=16) acted as the control group. Core–veneer interface of the specimens were subjected to shear force in the Universal Testing Machine (0.5 mm⋅min−1). Neither the zirconia core material (P=0.318) nor colouring (P=0.188) significantly affected the results (three-way analysis of variance, Tukey's test). But the results were significantly affected by the veneering ceramic (P=0.000). Control group exhibited significantly higher mean bond strength values (45.7±8) MPa than all other tested groups ((27.1±4.1)−(39.7±4.7) and (27.4±5.6)−(35.9±4.7) MPa with and without colouring, respectively) (P<0.001). While in zirconia–veneer test groups, predominantly mixed type of failures were observed with the veneering ceramic covering <1/3 of the substrate surface, in the metal–ceramic group, veneering ceramic was left adhered >1/3 of the metal surface. Colouring zirconia did not impair adhesion of veneering ceramic, but veneering ceramic had a significant influence on the core–veneer adhesion. Metal–ceramic adhesion was more reliable than all zirconia–veneer ceramics tested. PMID:24158142

  10. Asteroid bombardment and the core of Theia as possible sources for the Earth's late veneer component

    NASA Astrophysics Data System (ADS)

    Sleep, Norman H.

    2016-07-01

    The silicate Earth contains Pt-group elements in roughly chondritic relative ratios, but with absolute concentrations <1% chondrite. This veneer implies addition of chondrite-like material with 0.3-0.7% mass of the Earth's mantle or an equivalent planet-wide thickness of 5-20 km. The veneer thickness, 200-300 m, within the lunar crust and mantle is much less. One hypothesis is that the terrestrial veneer arrived after the moon-forming impact within a few large asteroids that happened to miss the smaller Moon. Alternatively, most of terrestrial veneer came from the core of the moon-forming impactor, Theia. The Moon then likely contains iron from Theia's core. Mass balances lend plausibility. The lunar core mass is ˜1.6 × 1021 kg and the excess FeO component in the lunar mantle is 1.3-3.5 × 1021 kg as Fe, totaling 3-5 × 1021 kg or a few percent of Theia's core. This mass is comparable to the excess Fe of 2.3-10 × 1021 kg in the Earth's mantle inferred from the veneer component. Chemically in this hypothesis, Fe metal from Theia's core entered the Moon-forming disk. H2O and Fe2O3 in the disk oxidized part of the Fe, leaving the lunar mantle near a Fe-FeO buffer. The remaining iron metal condensed, gathered Pt-group elements eventually into the lunar core. The silicate Moon is strongly depleted in Pt-group elements. In contrast, the Earth's mantle contained excess oxidants, H2O and Fe2O3, which quantitatively oxidized the admixed Fe from Theia's core, retaining Pt-group elements. In this hypothesis, asteroid impacts were relatively benign with ˜1 terrestrial event that left only thermophile survivors.

  11. Dental Calculus Arrest of Dental Caries

    PubMed Central

    Keyes, Paul H.; Rams, Thomas E.

    2016-01-01

    Background An inverse relationship between dental calculus mineralization and dental caries demineralization on teeth has been noted in some studies. Dental calculus may even form superficial layers over existing dental caries and arrest their progression, but this phenomenon has been only rarely documented and infrequently considered in the field of Cariology. To further assess the occurrence of dental calculus arrest of dental caries, this study evaluated a large number of extracted human teeth for the presence and location of dental caries, dental calculus, and dental plaque biofilms. Materials and methods A total of 1,200 teeth were preserved in 10% buffered formal saline, and viewed while moist by a single experienced examiner using a research stereomicroscope at 15-25× magnification. Representative teeth were sectioned and photographed, and their dental plaque biofilms subjected to gram-stain examination with light microscopy at 100× magnification. Results Dental calculus was observed on 1,140 (95%) of the extracted human teeth, and no dental carious lesions were found underlying dental calculus-covered surfaces on 1,139 of these teeth. However, dental calculus arrest of dental caries was found on one (0.54%) of 187 evaluated teeth that presented with unrestored proximal enamel caries. On the distal surface of a maxillary premolar tooth, dental calculus mineralization filled the outer surface cavitation of an incipient dental caries lesion. The dental calculus-covered carious lesion extended only slightly into enamel, and exhibited a brown pigmentation characteristic of inactive or arrested dental caries. In contrast, the tooth's mesial surface, without a superficial layer of dental calculus, had a large carious lesion going through enamel and deep into dentin. Conclusions These observations further document the potential protective effects of dental calculus mineralization against dental caries. PMID:27446993

  12. Dental Caries

    PubMed Central

    Burgess, Ralph C.

    1988-01-01

    Dental caries is one of the most prevalent diseases afflicting mankind. It reached a peak in the 1950s but has been declining drastically in recent years in children and young adults. This article describes the three contributing factors in dental caries: microbial plaque, tooth susceptibility, and diet, and discusses practical preventive measures which help to reduce caries incidence. Some of these, such as vaccines and antimicrobial varnishes, are still in the research stages, while others, such as sucrose substitutes, low-calorie sweeteners, and limitation of frequency of sugar snacks are well established and can be promoted by family physicians. PMID:21253193

  13. Comminution process to produce engineered wood particles of uniform size and shape with disrupted grain structure from veneer

    DOEpatents

    Dooley, James H; Lanning, David N

    2013-07-30

    Comminution process of wood veneer to produce wood particles, by feeding wood veneer in a direction of travel substantially normal to grain through a counter rotating pair of intermeshing arrays of cutting discs arrayed axially perpendicular to the direction of veneer travel, wherein the cutting discs have a uniform thickness (Td), to produce wood particles characterized by a length dimension (L) substantially equal to the Td and aligned substantially parallel to grain, a width dimension (W) normal to L and aligned cross grain, and a height dimension (H) substantially equal to the veneer thickness (Tv) and aligned normal to W and L, wherein the W.times.H dimensions define a pair of substantially parallel end surfaces with end checking between crosscut fibers.

  14. Porcelain laminate veneer restorations bonded with a three-liquid silane bonding agent and a dual-activated luting composite.

    PubMed

    Matsumura, Hideo; Aida, Yukiko; Ishikawa, Yumi; Tanoue, Naomi

    2006-12-01

    This clinical report describes the fabrication and bonding of porcelain laminate veneer restorations in a patient with anterior open spaces. Laminate veneer restorations made of feldspathic porcelain were etched with 5% hydrofluoric acid, rinsed under tap water, ultrasonically cleaned with methanol, and primed with a chemically activated three-liquid silane bonding agent (Clearfil Porcelain Bond). The enamel surfaces were etched with 40% phosphoric acid, rinsed with water, and primed with a two-liquid bonding agent (Clearfil New Bond) that contained a hydrophobic phosphate (10-methacryloyloxydecyl dihydrogen phosphate; MDP). The restorations were bonded with a dual-activated luting composite (Clapearl DC). The veneers have been functioning satisfactorily for an observation period of one year. Combined use of the Clearfil bonding agents and Clapearl DC luting composite is an alternative to conventional materials for seating porcelain laminate veneer restorations, although the system is inapplicable to dentin bonding.

  15. Effects of thermo-hygro-mechanical densification on the surface characteristics of trembling aspen and hybrid poplar wood veneers

    NASA Astrophysics Data System (ADS)

    Diouf, Papa Niokhor; Stevanovic, Tatjana; Cloutier, Alain; Fang, Chang-Hua; Blanchet, Pierre; Koubaa, Ahmed; Mariotti, Nicolas

    2011-02-01

    The effect of thermo-hygro-mechanical (THM) densification temperature on the surface color, roughness, wettability, and chemical composition of trembling aspen (Populus tremuloides) and hybrid poplar (Populus maximowiczii × P. balsamifera) veneers was investigated. Veneers were subjected to four THM densification temperatures (160 °C, 180 °C, 200 °C, and 220 °C). Veneer color darkened with increasing THM densification temperature. Surface roughness decreased between 160 °C and 200 °C. Wettability decreased after THM densification, but no significant difference was found between treated specimens. ATR-FTIR and XPS results confirmed that THM densification caused major chemical changes in veneer surfaces, and more pronounced at temperatures higher than 160 °C.

  16. Ocular prosthesis incorporating IPS e-max press scleral veneer and a literature review on non-integrated ocular prosthesis

    PubMed Central

    Da Costa, Godwin Clovis; Aras, Meena Ajay; Chalakkal, Paul; Da Costa, Michelle Clovis

    2017-01-01

    The article highlights a new method for the fabrication of an ocular prosthesis by the incorporation of a ceramic scleral veneer. The steps of fabrication include impression making, wax try-in, performing a “cut-back” on a selected stock eye, insertion of the IPS e-max press scleral veneer, finishing and insertion. It also includes a detailed review on non-integrated ocular prostheses. PMID:28149792

  17. Ocular prosthesis incorporating IPS e-max press scleral veneer and a literature review on non-integrated ocular prosthesis.

    PubMed

    Da Costa, Godwin Clovis; Aras, Meena Ajay; Chalakkal, Paul; Da Costa, Michelle Clovis

    2017-01-01

    The article highlights a new method for the fabrication of an ocular prosthesis by the incorporation of a ceramic scleral veneer. The steps of fabrication include impression making, wax try-in, performing a "cut-back" on a selected stock eye, insertion of the IPS e-max press scleral veneer, finishing and insertion. It also includes a detailed review on non-integrated ocular prostheses.

  18. A retrospective observational study of the effect of surface treatments and cementing media on the durability of gold palatal veneers.

    PubMed

    Chadwick, R G; Linklater, K I

    2004-01-01

    This paper reports on the results of a retrospective observational study that sought to determine both the longevity and effects of surface treatments of gold palatal veneers used to restore tooth surface loss. Details of all gold palatal veneers fabricated from Mattident 60 were sourced from hospital records spanning 11 years and 9 months. The case notes of each individual were accessed and, for each restoration, a note was made of the date and method of cementation, together with the period of patient follow-up. When patients continued their routine checkups, the records were scrutinized closely for evidence of restoration failure. This yielded a data set of 151 palatal gold veneer cementations for which the surface treatments and/or cementing media were known. Survival analysis by the Kaplan-Meier method of alumina blasted veneers revealed median survival times of 4,663 days when cemented with Panavia 21 and 687 days if cemented with Aquacem. Veneers that were alumina blasted, oxidized and cemented with Panavia 21 had a survival probability of 1.0. A Logrank test revealed highly statistically significant differences between the survival curves (p<0.0001). It was concluded that: (1) Alumina blasting the fit surface of a gold veneer prior to cementation with Panavia 21 resulted in a significantly more durable restoration compared to alumina blasting and cementation with Aquacem and no etching of tooth substance. (2) Due to low MST cementing, gold palatal veneers with a conventional glass polyalkenoate cement are not recommended. (3) Pre-treatment of gold palatal veneers by alumina blasting and oxidation prior to cementing with Panavia 21 appears to improve the chances of obtaining a dependable restoration. A greater number of restorations would be required to statistically test this trend.

  19. Clinical evaluation on porcelain laminate veneers bonded with light-cured composite: results up to 7 years.

    PubMed

    D'Arcangelo, Camillo; De Angelis, Francesco; Vadini, Mirco; D'Amario, Maurizio

    2012-08-01

    The purpose of this study was to evaluate the clinical performance of laminate porcelain veneers bonded with a light-cured composite. Thirty patients were restored with 119 porcelain laminate veneers. The veneers were studied for an observation time of 7 years. Marginal adaptation, marginal discoloration, secondary caries, color match, and anatomic form were clinically examined following modified United States Public Health Service (USPHS) criteria. Each restoration was also examined for cracks, fractures, and debonding. Pulp vitality was verified. In addition, plaque and gingival indexes and increase in gingival recession were recorded. Survival rate evaluating absolute failures and success rate describing relative failures were statistically determined, using both restoration and patient-related analyses. On the basis of the criteria used, most of the veneers rated Alfa. After 7 years, the results of the clinical investigation regarding marginal adaptation and marginal discoloration revealed only 2.5% and 4.2% Bravo ratings, respectively, among the 119 initially placed veneers. Using the restoration as the statistical unit, the survival rate was 97.5%, with a high estimated success probability of 0.843 after 7 years. Using the patient as the statistical unit, the survival rate was 90.0% and the estimated success probability after 7 years was 0.824. Gingival response to the veneers was all in the satisfactory range. Porcelain laminate veneers offer a predictable and successful treatment modality giving a maximum preservation of sound tooth. The preparation, cementation, and finishing procedures adopted are considered key factors for the long-term success and aesthetical result of the veneer restorations.

  20. Dental Training Films.

    ERIC Educational Resources Information Center

    Veterans Administration Medical Center, Washington, DC.

    This dental training films catalog is organized into two sections. Section I is a category listing of the films by number and title, indexed according to generalized headings; categories are as follow: anatomy, articulator systems, complete dentures, dental assisting, dental laboratory technology, dental materials, dental office emergencies,…

  1. Finding Dental Care

    MedlinePlus

    ... Finding Dental Care Where can I find low-cost dental care? Dental schools often have clinics that allow dental ... can I find more information? See Finding Low Cost Dental Care . ​​​​ WWNRightboxRadEditor2 Contact Us 1-866-232-4528 nidcrinfo@ ...

  2. Dental education and dental practice.

    PubMed Central

    Moore, J R

    1984-01-01

    This paper relates recent modes of dental practice to changes that the public and government are likely to ask the health care professions to make in the future. As usual they are asking for the best of all worlds. First, that we maintain the clinical model to the highest standards of personal dental care based and tested against the best research at our disposal, whilst we ensure there is no reduction in the high technical standards for which british dentists have a reputation. Second, that the profession is required to consider ways of providing care on the medicosocial model for the whole community at an economic level the country will afford. The broad changes in dental education have been reviewed, from the technical apprenticeship to the establishment of strong university departments in teaching hospitals. The importance of a sound biomedical foundation and of research both to education and the credibility of dental practice as a primary health care profession is stressed if the profession is to retain its position as a sister to medicine and not slide down to that of a technical ancillary. PMID:6374141

  3. Veneering technique for a Ti-6Al-7Nb framework used in a resin-bonded fixed partial denture with a highly filled indirect composite.

    PubMed

    Matsumura, Hideo; Yoneyama, Takayuki; Shimoe, Saiji

    2002-12-01

    This article presents a veneering technique for fixed partial denture frameworks made from a Ti-6Al-7Nb alloy. The fixed partial denture framework was prepared with a magnesia-based mold material and a centrifugal casting machine. An esthetic veneer was fabricated with a highly filled dual-polymerized composite material and a metal-conditioning agent. This technique can be applied as a standardized veneering procedure for the titanium alloy, for which porcelain fusing is currently difficult.

  4. Inlay-retained zirconia fixed dental prostheses: modified designs for a completely adhesive approach.

    PubMed

    Monaco, Carlo; Cardelli, Paolo; Ozcan, Mutlu

    2011-01-01

    Currently, there are many options for single-tooth replacement: metal-ceramic, all-ceramic, direct or indirect fibre-reinforced composite fixed dental prostheses (FDPs) or implants. Inlay-retained FDPs may especially be indicated when adjacent teeth have been previously restored and when implant placement is not possible or not indicated. In such cases, both metal-ceramic and fibre-reinforced composite FDPs have certain disadvantages. In this paper, we describe the use of all-ceramic inlay-retained FDPs with zirconia frameworks, veneered using a press-on technique.

  5. Effect of preliminary irradiation on the bond strength between a veneering composite and alloy.

    PubMed

    Matsumoto, Yoshifumi; Furuchi, Mika; Oshima, Akiko; Tanoue, Naomi; Koizumi, Hiroyasu; Matsumura, Hideo

    2010-01-01

    The shear bond strength of a veneering composite (Solidex) and silver-palladium-copper-gold alloy (Castwell M.C.12) was evaluated for different duration times and irradiance for preliminary photo-polymerization. A veneering composite was applied onto a cast disk. Preliminary photo irradiation was performed using different duration times or irradiance. After final polymerization, the bond strength and the spectral distribution of each curing unit were determined. Shear bond strength was significantly higher for 90 s (12.4 MPa), than that for 0 s (8.3 MPa). With regard to the effect of irradiance, that from Solidilite (11.4 MPa) was significantly higher than that from Sublite S at 3 cm (8.7 MPa). The irradiance of Hyper LII and Sublite S at 3 cm was higher than Sublite S at 15 cm or Solidilite unit. Long time irradiation and low intensity is effective for preliminary irradiation in order to enhance the bond strength.

  6. Esthetic rehabilitation of crowded maxillary anterior teeth utilizing ceramic veneers: a case report

    PubMed Central

    Ulusoy, Kivanç Utku

    2009-01-01

    Introduction In attempting to provide a solution for cases that have been compromised by malpositioned anterior teeth, clinicians traditionally decide orthodontic approach. Nevertheless, in some cases changes in tooth morphology, tooth size, and shape is compulsory for optimal aesthetics. The advent in contemporary aesthetic materials and preparation techniques empowered the clinicians to deliver a promising result with minimal biologic cost. This article presents the clinical considerations that must be addressed when providing a prosthetic restoration for crowded teeth. Case presentation A 23 years old Turkish female patient who had malaligned anterior teeth was rehabilitated with ceramic veneers due to her rejection of orthodontic treatment. The paper describes ceramic veneers can be an alternative treatment to orthodontic therapy under variety of preparation forms when patient has anterior malalignment and rejects the orthodontic treatment. Conclusion The new smile line was satisfactory for the patient and the esthetics was considered as excellent. PMID:19830068

  7. Dental Implant Surgery

    MedlinePlus

    Dental implant surgery Overview By Mayo Clinic Staff Dental implant surgery is a procedure that replaces tooth roots with ... look and function much like real ones. Dental implant surgery can offer a welcome alternative to dentures ...

  8. Dental Holography

    NASA Astrophysics Data System (ADS)

    Dirtoft, Ingegerd

    1983-12-01

    Ten years have passed since the first articles appeared in this new field. The qualities of the laser light together with the need of contactless 3-D measurements for different dental purposes seemed to be extremely promising, but still just a few scientists have used the method and mostly for laboratory studies. For some reason there has been a preponderance for orthodontic measurements. This seems to be a bit peculiar from holographic view compared with measurements for engineering purposes, which usually are made on metals. So naturally holography can become a clinical tool for measurements in the field of fixed bridges, removable partial dentures and implants. One of the problems is that the need for holography in dental research must be fulfilled in collaboration with physicists. Only a two-way communication during an entire experiment can balance both technical and odontological demands and thus give practical and clinical important results. The need for an easy way of handling the evaluation to get all required information is another problem and of course the holographic equipment must be converted to a box easy to handle for everyone. At last the position of dental holography today is going to be carefully examined together with an attempt to look into the hopefully exciting and not to utopic future for this research field.

  9. Shear bond strength of veneering ceramic to coping materials with different pre-surface treatments

    PubMed Central

    Anuar, Norsamihah; Ahmad, Marlynda

    2016-01-01

    PURPOSE Pre-surface treatments of coping materials have been recommended to enhance the bonding to the veneering ceramic. Little is known on the effect on shear bond strength, particularly with new coping material. The aim of this study was to investigate the shear bond strength of veneering ceramic to three coping materials: i) metal alloy (MA), ii) zirconia oxide (ZO), and iii) lithium disilicate (LD) after various pre-surface treatments. MATERIALS AND METHODS Thirty-two (n = 32) discs were prepared for each coping material. Four pre-surface treatments were prepared for each sub-group (n = 8); a) no treatment or control (C), b) sandblast (SB), c) acid etch (AE), and d) sandblast and acid etch (SBAE). Veneering ceramics were applied to all discs. Shear bond strength was measured with a universal testing machine. Data were analyzed with two-way ANOVA and Tukey's multiple comparisons tests. RESULTS Mean shear bond strengths were obtained for MA (19.00 ± 6.39 MPa), ZO (24.45 ± 5.14 MPa) and LD (13.62 ± 5.12 MPa). There were statistically significant differences in types of coping material and various pre-surface treatments (P<.05). There was a significant correlation between coping materials and pre-surface treatment to the shear bond strength (P<.05). CONCLUSION Shear bond strength of veneering ceramic to zirconia oxide was higher than metal alloy and lithium disilicate. The highest shear bond strengths were obtained in sandblast and acid etch treatment for zirconia oxide and lithium disilicate groups, and in acid etch treatment for metal alloy group. PMID:27826383

  10. A study on provisional cements, cementation techniques, and their effects on bonding of porcelain laminate veneers.

    PubMed

    Vinod Kumar, G; Soorya Poduval, T; Bipin Reddy; Shesha Reddy, P

    2014-03-01

    Minimal tooth preparation is required for porcelain laminate veneers, but interim restorations are a must to protect their teeth against thermal insult, chemical irritation, and to provide aesthetics. Cement remaining after the removal of the provisional restoration can impair the etching quality of the tooth surface and fit and final bonding of the porcelain laminate veneer. This in vitro study examined the tooth surface for remaining debris of cement after removal of a provisional restoration. Determine the presence of cement debris on prepared tooth surface subsequent to the removal of provisional restoration. Determine the cement with the least residue following the cleansing procedures. Determine the effect of smear layer on the amount of residual luting cement. Eighty-four extracted natural anterior teeth were prepared for porcelain laminate veneers. For half of the teeth, the smear layer was removed before luting provisional restorations. Veneer provisional restorations were fabricated and luted to teeth with six bonding methods: varnish combined with glass ionomer cement (GIC), varnish combined with resin modified GIC, varnish, spot etching combined with dual-cure luting cement, adhesive combined with GIC, adhesive combined with resin modified GIC, and adhesive, spot etching combined with dual-cure luting cement. After removal of provisional restorations 1 week later, the tooth surface was examined for residual luting material with SEM. Traces of cement debris were found on all the prepared teeth surfaces for all six groups which were cemented with different methods. Cement debris was seen on teeth subsequent to the removal of provisional's. Dual-cure cement had the least residue following the cleansing procedures. Presence of smear layer had no statistical significance in comparison with cement residue. With the use of adhesive the cement debris was always found to be more than with the use of varnish. GIC showed maximum residual cement followed by dual-cure.

  11. An alternative treatment approach to gingival recession: gingiva-colored partial porcelain veneers: a clinical report.

    PubMed

    Capa, Nuray

    2007-08-01

    This clinical report describes the treatment of excessive gingival recession involving maxillary right and left central incisors in a 30-year-old woman. The loss of the gingival soft tissue caused an increase in crown length. Gingiva-colored partial porcelain laminate veneers were applied to imitate the lost gingiva and to provide a natural anatomical tooth length. This method may be a minimally invasive alternative treatment method for gingival soft tissue loss, providing esthetic results and patient satisfaction.

  12. Influence of surface modification techniques on shear bond strength between different zirconia cores and veneering ceramics

    PubMed Central

    Rismanchian, Mansour; Savabi, Omid; Ashtiani, Alireza Hashemi

    2011-01-01

    PURPOSE Veneering porcelain might be delaminated from underlying zirconia-based ceramics. The aim of this study was the evaluation of the effect of different surface treatments and type of zirconia (white or colored) on shear bond strength (SBS) of zirconia core and its veneering porcelain. MATERIALS AND METHODS Eighty zirconia disks (40 white and 40 colored; 10 mm in diameter and 4 mm thick) were treated with three different mechanical surface conditioning methods (Sandblasting with 110 µm Al2O3 particle, grinding, sandblasting and liner application). One group had received no treatment. These disks were veneered with 3 mm thick and 5 mm diameter Cercon Ceram Kiss porcelain and SBS test was conducted (cross-head speed = 1 mm/min). Two and one way ANOVA, Tukey's HSD Past hoc, and T-test were selected to analyzed the data (α=0.05). RESULTS In this study, the factor of different types of zirconia ceramics (P=.462) had no significant effect on SBS, but the factors of different surface modification techniques (P=.005) and interaction effect (P=.018) had a significant effect on SBS. Within colored zirconia group, there were no significant differences in mean SBS among the four surface treatment subgroups (P=0.183). Within white zirconia group, "Ground group" exhibited a significantly lower SBS value than "as milled" or control (P=0.001) and liner (P=.05) groups. CONCLUSION Type of zirconia did not have any effect on bond strength between zirconia core and veneer ceramic. Surface treatment had different effects on the SBS of the different zirconia types and grinding dramatically decreased the SBS of white zirconia-porcelain. PMID:22259706

  13. [Effect of ceramic thickness and resin cement shades on final color of heat-pressed ceramic veneers].

    PubMed

    Ren, D F; Zhan, K R; Chen, X D; Xing, W Z

    2017-02-09

    Objective: To analyze the effect of ceramic materials thickness and resin cement shades on the final color of ceramic veneers in the discolored teeth, and to investigate the color agreement of try-in pastes to the corresponding resin cements. Methods: Sixty artificial maxillary central incisor teeth (C2 shade) were used to simulate the natural discolored teeth and prepared according to veneer tooth preparation protocol. Veneers of different thickness in the body region (0.50 and 0.75 mm) were fabricated using ceramic materials (LT A2 shade, IPS e.max Press). The ceramic veneer specimens were bonded to the artificial teeth using the 6 shades of resin cements (Variolink Veneer: shades of LV-3, LV-2, HV+3; RelyX™ Veneer: shades of TR, A3, WO) (n=5). A clinical spectrophotometer was used to measure the color parameters of ceramic veneers at the cervical, body and incisal regions. Color changes of veneers before and after cementation were calculated and registered as ΔE1, and the changes between try-in paste and the corresponding resin cements were registered as ΔE2. Results: Three-way ANOVA indicated that ΔE1 and ΔE2 values were significantly affected by the ceramic thickness, resin cement shades and measuring regions (P<0.05). The ΔE1 values of six shades ranged from 0.59-8.27. The ΔE1 values were more than 2.72 when the ceramic veneers were cemented with resin cements in shades of HV+3 and WO. The ΔE2 values of six shades ranged from 0.60-2.56. The shades of HV+3, WO and A3 resin cements were more than 1.60. Conclusions: Different thickness of ceramic materials, resin cement shades and measuring regions could affect the final color of ceramic veneers. The color differences of some resin cements and corresponding try-in pastes might be observed in clinical practice.

  14. Development of partial rock veneers by root throw in a subalpine setting

    USGS Publications Warehouse

    Osterkamp, W.R.; Toy, T.J.; Lenart, M.T.

    2006-01-01

    Rock veneers stabilize hillslope surfaces, occur especially in areas of immature soil, and form through a variety of process sets that includes root throw. Near Westcliffe, Colorado, USA, data were collected from a 20 ?? 500 m transect on the east slope of the Sangre de Cristo Mountains. Ages of pit/mound complexes with rock fragments exposed at the surface by root throw ranged from recent (freshly toppled tree) to unknown (complete tree decay). Calculations based on dimensions of the pit/mound complexes, estimated time of free topppling, sizes of exposed rock fragments, and percentage rock covers at pit/mound complexes, as well as within the transect area, indicate that recent rates of root throw have resulted in only partial rock veneering since late Pleistocene deglaciation. Weathering of rock fragments prevent development of an extensive rock veneer and causes a balance, achieved within an estimated 700 years, between the rates of rock-fragment exposure by root throw and clast disintegration by chemical reduction. The estimated rate of rock-fragment reduction accounts for part of the fluvial sediment yields observed for forested subalpine areas of western North America. Copyright ?? 2005 John Wiley & Sons, Ltd.

  15. Fracture resistance of zirconia-composite veneered crowns in comparison with zirconia-porcelain crowns.

    PubMed

    Alsadon, Omar; Patrick, David; Johnson, Anthony; Pollington, Sarah; Wood, Duncan

    2017-02-11

    The objectives were to evaluate the fracture resistance and stress concentration in zirconia/composite veneered crowns in comparison to zirconia/porcelain crowns using occlusal fracture resistance and by stress analysis using finite element analysis method. Zirconia substructures were divided into two groups based on the veneering material. A static load was applied occlusally using a ball indenter and the load to fracture was recorded in Newtons (N). The same crown design was used to create 3D crown models and evaluated using FEA. The zirconia/composite crowns subjected to static occlusal load showed comparable results to the zirconia/porcelain crowns. Zirconia/composite crowns showed higher stress on the zirconia substructure at 63.6 and 50.9 MPa on the zirconia substructure veneered with porcelain. In conclusion, zirconia/composite crowns withstood high occlusal loads similar to zirconia/porcelain crowns with no significant difference. However, the zirconia/composite crowns showed higher stress values than the zirconia/porcelain crowns at the zirconia substructure.

  16. Post-fatigue fracture resistance of metal core crowns: press-on metal ceramic versus a conventional veneering system

    PubMed Central

    Agustín-Panadero, Rubén; Campos-Estellés, Carlos; Labaig-Rueda, Carlos

    2015-01-01

    Background The aim of this in vitro study was to compare the mechanical failure behavior and to analyze fracture characteristics of metal ceramic crowns with two veneering systems – press-on metal (PoM) ceramic versus a conventional veneering system – subjected to static compressive loading. Material and Methods Forty-six crowns were constructed and divided into two groups according to porcelain veneer manufacture. Group A: 23 metal copings with porcelain IPS-InLine veneering (conventional metal ceramic). Group B: 23 metal copings with IPS-InLine PoM veneering porcelain. After 120,000 fatigue cycles, the crowns were axially loaded to the moment of fracture with a universal testing machine. The fractured specimens were examined under optical stereomicroscopy and scanning electron microscope. Results Fracture resistance values showed statistically significant differences (Student’s t-test) regarding the type of ceramic veneering technique (p=0.001): Group A (conventional metal ceramics) obtained a mean fracture resistance of 1933.17 N, and Group B 1325.74N (Press-on metal ceramics). The most common type of fracture was adhesive failure (with metal exposure) (p=0.000). Veneer porcelain fractured on the occlusal surface following a radial pattern. Conclusions Metal ceramic crowns made of IPS InLine or IPS InLine PoM ceramics with different laboratory techniques all achieved above-average values for clinical survival in the oral environment according to ISO 6872. Crowns made with IPS InLine by conventional technique resisted fracture an average of 45% more than IPS InLine PoM fabricated with the press-on technique. Key words:Mechanical failure, conventional feldspathic, pressable ceramic, chewing simulator, thermocycling, compressive testing, fracture types, scanning electron microscope. PMID:26155346

  17. Degree of conversion of a resin cement light-cured through ceramic veneers of different thicknesses and types.

    PubMed

    Runnacles, Patrício; Correr, Gisele Maria; Baratto Filho, Flares; Gonzaga, Carla Castiglia; Furuse, Adilson Yoshio

    2014-01-01

    During the cementation of ceramic veneers the polymerization of resin cements may be jeopardized if the ceramics attenuate the irradiance of the light-curing device. The aim of this study was to evaluate the effect of different types and thicknesses of ceramic veneers on the degree of conversion of a light-cured resin-based cement (RelyX Veneer). The cement was light-cured after interposing ceramic veneers [IPS InLine, IPS Empress Esthetic, IPS e.max LT (low translucency) and IPS e.max HT (high translucency) - Ivoclar Vivadent] of four thicknesses (0.5 mm, 1.0 mm, 1.5 mm and 2.0 mm). As control, the cement was light-cured without interposition of ceramics. The degree of conversion was evaluated by FTIR spectroscopy (n=5). Data were analyzed with one-way ANOVA and Tukey's test (α=0.05). Significant differences were observed among groups (p<0.001). The degree of conversion was similar to the control for all light-cured groups with interposition of ceramics of 0.5 mm and 1.0 mm (p>0.05). Among 1.5-mm-thick veneers, IPS e.max LT was the only one that showed different results from the control (p<0.05). At the thickness of 2.0 mm, only the IPS e.max LT and HT veneers were able to produce cements with degrees of conversion similar to the control (p>0.05). The degree of conversion of the evaluated light-cured resin cement depends on the thickness and type of ceramics employed when veneers thicker than 1.5 mm are cemented.

  18. Effect of Resin Bonded Luting Agents Influencing Marginal Discrepancy in All Ceramic Complete Veneer Crowns

    PubMed Central

    Sathyamoorthy, Anusha; Ranganathan, Hemalatha; Murthykumar, Karthikeyan

    2016-01-01

    Introduction Marginal discrepancy severely affects the long term success of All ceramic complete veneer crowns. The precise role of resin luting agents influencing this phenomenon needs to be explored further. Aim To estimate and compare the marginal discrepancy in CAD/CAM processed All ceramic complete veneer crowns prior and following luting with resin bonded luting agents. Materials and Methods Extracted human maxillary first premolars were randomly allocated into four groups of 27 samples each Viz., Group I-Resin Modified Glass Ionomer Cement (GIC) (RelyX), Group II-Bis-GMA based dual cure resin cement (Variolink II), Group III-PMMA based resin cement (Superbond), Group IV- Urethane Dimethacrylate resin cement (Calibra). Following tooth preparation, CAD/CAM All ceramic complete veneer crowns were fabricated and sectioned and marginal discrepancy was evaluated using a scanning electron microscope (TESCAN, Magnification power-1,00,000x) prior and after luting with the experimental resin cements. Results The vertical and horizontal discrepancy before and after cementation with Group I [270.08±103.10μm, 165.3±53.00μm and 270.86±102.70μm, 166.62±54.96μm respectively]; Group II [254.21±79.20μm, 117.75±24.29μm and 234.81±79μm, 116.89±18.22μm respectively]; Group III [272.47±86.25μm, 142.08±50.83μm and 251.82±62.69μm, 136.07±44.95μm respectively]; Group IV were [260.28±64.81μm, 116.98±17.71μm and 233.08±69.44μm, 116.58±21.13μm respectively]. ANOVA inferred a statistically significant difference between the four test specimen with regards to vertical and horizontal marginal discrepancy after cementation (F=9.092, p<0.001), (F=10.97, p<0.001). Tukey HSD Post-hoc test observed significant differences in vertical and horizontal marginal discrepancies between the resin modified glass ionomer and resin cements (p<0.05). Conclusion Resin cements exhibited a greater reduction in the marginal discrepancy than the resin modified glass ionomer

  19. Influence of porcelain veneering on the marginal fit of Digident and Lava CAD/CAM zirconia ceramic crowns

    PubMed Central

    Pak, Hyun-Soon; Han, Jung-Suk; Lee, Jai-Bong; Kim, Sung-Hun

    2010-01-01

    PURPOSE Marginal fit is a very important factor considering the restoration's long-term success. However, adding porcelain to copings can cause distortion and lead to an inadequate fit which exposes more luting material to the oral environment and causes secondary caries. The purpose of this study was to compare the marginal fit of 2 different all-ceramic crown systems before and after porcelain veneering. This study was also intended to verify the marginal fit of crowns originated from green machining of partially sintered blocks of zirconia (Lava CAD/CAM system) and that of crowns obtained through machining of fully sintered blocks of zirconia (Digident CAD/CAM system). MATERIALS AND METHODS 20 crowns were made per each system and the marginal fit was evaluated through a light microscope with image processing (Accura 2000) at 50 points that were randomly selected. Each crown was measured twice: the first measurement was done after obtaining a 0.5 mm coping and the second measurement was done after porcelain veneering. The means and standard deviations were calculated and statistical inferences among the 2 groups were made using independent t-test and within the same group through paired t-test. RESULTS The means and standard deviations of the marginal fit were 61.52 ± 2.88 µm for the Digident CAD/CAM zirconia ceramic crowns before porcelain veneering and 83.15 ± 3.51 µm after porcelain veneering. Lava CAD/CAM zirconia ceramic crowns showed means and standard deviations of 62.22 ± 1.78 µm before porcelain veneering and 82.03 ± 1.85 µm after porcelain veneering. Both groups showed significant differences when analyzing the marginal gaps before and after porcelain veneering within each group. However, no significant differences were found when comparing the marginal gaps of each group before porcelain veneering and after porcelain veneering as well. CONCLUSION The 2 all-ceramic crown systems showed marginal gaps that were within a reported clinically

  20. Influence of Different Types of Resin Luting Agents on Color Stability of Ceramic Laminate Veneers Subjected to Accelerated Artificial Aging.

    PubMed

    Silami, Francisca Daniele Jardilino; Tonani, Rafaella; Alandia-Román, Carla Cecilia; Pires-de-Souza, Fernanda de Carvalho Panzeri

    2016-01-01

    The aim of this study was to evaluate the influence of accelerated aging (AAA) on the color stability of resin cements for bonding ceramic laminate veneers of different thicknesses. The occlusal surfaces of 80 healthy human molars were flattened. Ceramic laminate veneers (IPS e-max Ceram) of two thicknesses (0.5 and 1.0 mm) were bonded with three types of luting agents: light-cured, conventional dual and self-adhesive dual cement. Teeth without restorations and cement samples (0.5 mm) were used as control. After initial color evaluations, the samples were subjected to AAA for 580 h. After this, new color readouts were made, and the color stability (ΔE) and luminosity (ΔL) data were analyzed. The greatest color changes (p<0.05) occurred when 0.5 mm veneers were fixed with light-cured cement and the lowest when 1.0 mm veneers were fixed with conventional dual cement. There was no influence of the restoration thickness when the self-adhesive dual cement was used. When veneers were compared with the control groups, it was verified that the cement samples presented the greatest alterations (p<0.05) in comparison with both substrates and restored teeth. Therefore, it was concluded that the thickness of the restoration influences color and luminosity changes for conventional dual and light-cured cements. The changes in self-adhesive cement do not depend on restoration thickness.

  1. Child Indicators: Dental Health.

    ERIC Educational Resources Information Center

    Lewit, Eugene M.; Kerrebrock, Nancy

    1998-01-01

    Reviews measures of dental health in children and the evidence on child dental health. Although children's dental health has improved over the past two decades, many poor children do not receive necessary dental health services, and reasons for this failure are summarized. (SLD)

  2. Weaker dental enamel explains dental decay.

    PubMed

    Vieira, Alexandre R; Gibson, Carolyn W; Deeley, Kathleen; Xue, Hui; Li, Yong

    2015-01-01

    Dental caries continues to be the most prevalent bacteria-mediated non-contagious disease of humankind. Dental professionals assert the disease can be explained by poor oral hygiene and a diet rich in sugars but this does not account for caries free individuals exposed to the same risk factors. In order to test the hypothesis that amount of amelogenin during enamel development can influence caries susceptibility, we generated multiple strains of mice with varying levels of available amelogenin during dental development. Mechanical tests showed that dental enamel developed with less amelogenin is "weaker" while the dental enamel of animals over-expressing amelogenin appears to be more resistant to acid dissolution.

  3. Dental education in Colombia

    PubMed Central

    Jaramillo, Jorge A.; Pulido, Jairo H. Ternera; Núñez, Jaime A. Castro; Bird, William F.; Komabayashi, Takashi

    2014-01-01

    This article describes Colombia's development of formal dentistry, its dental school system, curriculum, and dental licensure, and current issues in oral health care. In 1969, there were only 4 dental schools in Colombia; at this writing there are 21. Five dental schools are public and the other 16 are private. Nearly all classes are conducted in Spanish. Undergraduate pre-dental coursework is not a prerequisite for dental school in Colombia. To obtain licensure, Colombian dental students must complete 5 years of study in dental school, earn a diploma, and work for the government for 1 year. There are approximately 41,400 dentists in Colombia, and the number is increasing quickly. However, the unemployment rate among dentists is very high, even though graduation from dental school is extremely difficult. Although the 1,100:1 ratio of citizens to dentists is considered satisfactory, access to dental care is limited due to the high rate of poverty. PMID:20339245

  4. Atypical Forensic Dental Identifications.

    PubMed

    Cardoza, Anthony R; Wood, James D

    2015-06-01

    Forensic dental identification specialists are typically the last conventional option for postmortem identification. Forensic dental identification is most often accomplished by comparing radiographs of the decedent's teeth with the dental radiographs obtained from the dentist of the suspected victim. Unfortunately, antemortem dental radiographs are not always available. When presented with this challenge, the authors of this article have been successful in completing identifications using means other than dental radiographic comparison.

  5. Comminution process to produce wood particles of uniform size and shape with disrupted grain structure from veneer

    DOEpatents

    Dooley, James H.; Lanning, David N.

    2017-03-28

    Comminution process of wood veneer to produce wood particles, by feeding wood veneer in a direction of travel substantially normal to grain through a counter rotating pair of intermeshing arrays of cutting discs arrayed axially perpendicular to the direction of wood veneer travel, wherein the cutting discs have a uniform thickness (Td), to produce wood particles characterized by a length dimension (L) substantially equal to the Td and aligned substantially parallel to grain, a width dimension (W) normal to L and aligned cross grain, and a height dimension (H) aligned normal to W and L, wherein the W.times.H dimensions define a pair of substantially parallel end surfaces with end checking between crosscut fibers.

  6. Fracture load and failure analysis of zirconia single crowns veneered with pressed and layered ceramics after chewing simulation.

    PubMed

    Stawarczyk, Bogna; Ozcan, Mutlu; Roos, Malgorzata; Trottmann, Albert; Hämmerle, Christoph H F

    2011-01-01

    This study determined the fracture load of zirconia crowns veneered with four overpressed and four layered ceramics after chewing simulation. The veneered zirconia crowns were cemented and subjected to chewing cycling. Subsequently, the specimens were loaded at an angle of 45° in a Universal Testing Machine to determine the fracture load. One-way ANOVA, followed by a post-hoc Scheffé test, t-test and Weibull statistic were performed. Overpressed crowns showed significantly lower fracture load (543-577 N) compared to layered ones (805-1067 N). No statistical difference was found between the fracture loads within the overpressed group. Within the layered groups, LV (1067 N) presented significantly higher results compared to LC (805 N). The mean values of all other groups were not significantly different. Single zirconia crowns veneered with overpressed ceramics exhibited lower fracture load than those of the layered ones after chewing simulation.

  7. Evaluation of the color reproducibility of all-ceramic restorations fabricated by the digital veneering method

    PubMed Central

    Kim, Jae-Hong; Kim, Ki-Baek; Kim, Woong-Chul; Kim, Hae-Young

    2014-01-01

    PURPOSE The objective of this study was to evaluate the clinical acceptability of all-ceramic crowns fabricated by the digital veneering method vis-à-vis the traditional method. MATERIALS AND METHODS Zirconia specimens manufactures by two different manufacturing method, conventional vs digital veneering, with three different thickness (0.3 mm, 0.5 mm, 0.7 mm) were prepared for analysis. Color measurement was performed using a spectrophotometer for the prepared specimens. The differences in shade in relation to the build-up method were calculated by quantifying ΔE* (mean color difference), with the use of color difference equations representing the distance from the measured values L*, a*, and b*, to the three-dimensional space of two colors. Two-way analysis of variance (ANOVA) combined with a Tukey multiple-range test was used to analyze the data (α=0.05). RESULTS In comparing means and standard deviations of L*, a*, and b* color values there was no significant difference by the manufacturing method and zirconia core thickness according to a two-way ANOVA. The color differences between two manufacturing methods were in a clinically acceptable range less than or equal to 3.7 in all the specimens. CONCLUSION Based on the results of this study, a carefully consideration is necessary while selecting upper porcelain materials, even if it is performed on a small scale. However, because the color reproducibility of the digital veneering system was within the clinically acceptable range when comparing with conventional layering system, it was possible to estimate the possibility of successful aesthetic prostheses in the latest technology. PMID:24843390

  8. Porcelain laminate veneer conditioning for orthodontic bonding: SEM-EDX analysis.

    PubMed

    Aksakalli, Sertac; Ileri, Zehra; Yavuz, Tevfik; Malkoc, Meral Arslan; Ozturk, Nilgun

    2015-09-01

    The purpose of this in vitro study was to evaluate and compare the effects of different surface treatments and laser irradiation on the bond strength of brackets bonded to porcelain laminate veneer. Porcelain laminate veneer specimens were embedded in the centers of acrylic resin blocks. Thirty-nine teeth were used for shear bond strength testing and the remaining three (one tooth for each group) were used for evaluation of the debonded bracket interface. Specimens were randomly divided into three groups, each containing 13 specimens. The details of the groups are as follows: Group SB, sandblasting with alumina particles (50 μm); Group HFA, 9.6 % hydrofluoric acid etching; Group ER, erbium-doped yttrium-aluminum-garnet (Er: YAG) irradiation (from 1 mm distance, 2 W, 10 Hz for 10 s). After conditioning, the upper central brackets were bonded to the porcelain surfaces. Porcelain laminate veneers were examined under stereomicroscope for adhesive remnant index and surface damage after debonding. The highest shear bond strength values were obtained with Group HFA (10.8 ± 3.8 MPa) and Group ER (9.3 ± 1.5 MPa), whereas Group SB revealed the lowest values. Scanning electron microscopy energy-dispersive X-ray (SEM-EDX) analysis revealed that the silicon level in the porcelain decreased after debonding in all groups. The sandblasting method did not demonstrate any ideal bond strength values; however, the 9.6 % hydrofluoric acid etching and Er: YAG laser did. There were no significant differences among all groups in terms of laminate surface damages. The Er: YAG laser therefore can be selected for ideal bond strength and minimal damage to porcelain laminates.

  9. Effect of different veneering techniques on the fracture strength of metal and zirconia frameworks

    PubMed Central

    Turk, Ayse Gozde; Ulusoy, Mubin; Yuce, Mert

    2015-01-01

    PURPOSE To determine whether the fracture strengths and failure types differed between metal and zirconia frameworks veneered with pressable or layering ceramics. MATERIALS AND METHODS A phantom molar tooth was prepared and duplicated in 40 cobalt-chromium abutments. Twenty metal (IPS d.SIGN 15, Ivoclar, Vivadent, Schaan, Liechtenstein) and 20 zirconia (IPS e.max ZirCAD, Ivoclar) frameworks were fabricated on the abutments. Each framework group was randomly divided into 2 subgroups according to the veneering material: pressable and layering ceramics (n=10). Forty molar crowns were fabricated, cemented onto the corresponding abutments and then thermocycled (5-55℃, 10,000 cycles). A load was applied in a universal testing machine until a fracture occurred on the crowns. In addition, failure types were examined using a stereomicroscope. Fracture load data were analyzed using one-way ANOVA and Tukey HSD post-hoc tests at a significance level of 0.05. RESULTS The highest strength value was seen in metal-pressable (MP) group, whereas zirconia-pressable (ZP) group exhibited the lowest one. Moreover, group MP showed significantly higher fracture loads than group ZP (P=.015) and zirconia-layering (ZL) (P=.038) group. No significant difference in fracture strength was detected between groups MP and ML, and groups ZP and ZL (P>.05). Predominant fracture types were cohesive for metal groups and adhesive for zirconia groups. CONCLUSION Fracture strength of a restoration with a metal or a zirconia framework was independent of the veneering techniques. However, the pressing technique over metal frameworks resisted significantly higher fracture loads than zirconia frameworks. PMID:26816575

  10. The Last Stages of Terrestrial Planet Formation: Dynamical Friction and the Late Veneer

    NASA Astrophysics Data System (ADS)

    Schlichting, Hilke E.; Warren, Paul H.; Yin, Qing-Zhu

    2012-06-01

    The final stage of terrestrial planet formation consists of the clean-up of residual planetesimals after the giant impact phase. Dynamically, a residual planetesimal population is needed to damp the high eccentricities and inclinations of the terrestrial planets to circular and coplanar orbits after the giant impact stage. Geochemically, highly siderophile element (HSE) abundance patterns inferred for the terrestrial planets and the Moon suggest that a total of about 0.01 M⊕ of chondritic material was delivered as "late veneer" by planetesimals to the terrestrial planets after the end of giant impacts. Here, we combine these two independent lines of evidence for a leftover population of planetesimals and show that: (1) a residual population of small planetesimals containing 0.01 M⊕ is able to damp the high eccentricities and inclinations of the terrestrial planets after giant impacts to their observed values. (2) At the same time, this planetesimal population can account for the observed relative amounts of late veneer added to the Earth, Moon, and Mars provided that the majority of the accreted late veneer was delivered by small planetesimals with radii <~ 10 m. These small planetesimal sizes are required to ensure efficient damping of the planetesimal's velocity dispersion by mutual collisions, which in turn ensures sufficiently low relative velocities between the terrestrial planets and the planetesimals such that the planets' accretion cross sections are significantly enhanced by gravitational focusing above their geometric values. Specifically, we find that, in the limit that the relative velocity between the terrestrial planets and the planetesimals is significantly less than the terrestrial planets' escape velocities, gravitational focusing yields a mass accretion ratio of Earth/Mars ~(ρ⊕/ρmars)(R⊕/Rmars)4 ~ 17, which agrees well with the mass accretion ratio inferred from HSEs of 12-23. For the Earth-Moon system, we find a mass accretion ratio of

  11. THE LAST STAGES OF TERRESTRIAL PLANET FORMATION: DYNAMICAL FRICTION AND THE LATE VENEER

    SciTech Connect

    Schlichting, Hilke E.; Warren, Paul H.; Yin Qingzhu

    2012-06-10

    The final stage of terrestrial planet formation consists of the clean-up of residual planetesimals after the giant impact phase. Dynamically, a residual planetesimal population is needed to damp the high eccentricities and inclinations of the terrestrial planets to circular and coplanar orbits after the giant impact stage. Geochemically, highly siderophile element (HSE) abundance patterns inferred for the terrestrial planets and the Moon suggest that a total of about 0.01 M{sub Circled-Plus} of chondritic material was delivered as 'late veneer' by planetesimals to the terrestrial planets after the end of giant impacts. Here, we combine these two independent lines of evidence for a leftover population of planetesimals and show that: (1) a residual population of small planetesimals containing 0.01 M{sub Circled-Plus} is able to damp the high eccentricities and inclinations of the terrestrial planets after giant impacts to their observed values. (2) At the same time, this planetesimal population can account for the observed relative amounts of late veneer added to the Earth, Moon, and Mars provided that the majority of the accreted late veneer was delivered by small planetesimals with radii {approx}< 10 m. These small planetesimal sizes are required to ensure efficient damping of the planetesimal's velocity dispersion by mutual collisions, which in turn ensures sufficiently low relative velocities between the terrestrial planets and the planetesimals such that the planets' accretion cross sections are significantly enhanced by gravitational focusing above their geometric values. Specifically, we find that, in the limit that the relative velocity between the terrestrial planets and the planetesimals is significantly less than the terrestrial planets' escape velocities, gravitational focusing yields a mass accretion ratio of Earth/Mars {approx}({rho}{sub Circled-Plus }/{rho}{sub mars})(R{sub Circled-Plus }/R{sub mars}){sup 4} {approx} 17, which agrees well with the mass

  12. Effect of UV exposure on the surface chemistry of wood veneers treated with ionic liquids

    NASA Astrophysics Data System (ADS)

    Patachia, Silvia; Croitoru, Catalin; Friedrich, Christian

    2012-07-01

    In this paper, the influence of four types of imidazolium-based ionic liquids (ILs) on the chemical alteration of the surface of wood veneers exposed to 254 nm UV irradiation have been studied by using image analysis, Fourier transform infrared spectroscopy and surface energy calculation. The wood treated with ionic liquids showed better stability to UV light, as demonstrated by the low lignin, carbonyl index and cellulose crystallinity index variation, as well as very small color modification of the surface with the increase of the UV exposure period, by comparing to non-treated wood. The results show that the tested ionic liquids could be effective as UV stabilizers.

  13. A 10-Year Clinical Evaluation of Resin-Bonded Fixed Dental Prostheses on Non-Prepared Teeth.

    PubMed

    Piemjai, Morakot; Özcan, Mutlu; Garcia-Godoy, Franklin; Nakabayashi, Nobuo

    2016-06-01

    This study evaluated the conditions of the non-invasive resin-bonded fixed dental prostheses (FDP) and patient satisfaction up to 10 years of clinical function. A total of 23 patients who required fixed prostheses in the areas of mandibular anterior and premolar, and maxillary anterior region received resin-bonded restorations between 1999-2003. In 13 patients with 14 edentulous areas were restored with an adhesive pontic (natural tooth, acrylic and porcelain). Two indirect proximal veneers using resin composite were placed in each space in 10 patients having 13 edentulous spaces. All prostheses were bonded to the proximal surface of adjacent teeth using resin cement based on 4-META/MMA-TBB. No debonding of proximal veneers but 4 pontic debonding was observed which were rebonded and remained functional until final follow up. The abutments in pontic and proximal veneer groups were free of caries and hypersensitivity. Periodontal health was improved after treatment and was maintained for 10 years except for 4 abutments that still showed some bleeding on probing. Non-invasive resin-bonded FDPs are simple, pain-free, less costly treatment procedures that could provide acceptable clinical longevity with high patient satisfaction.

  14. Dental Auxiliary Occupations. Interim Report.

    ERIC Educational Resources Information Center

    Kingston, Richard D.

    As part of a dental auxiliaries project, a Dental Auxiliary National Technical Advisory Committee was established, and its major undertaking was to assist in the development of a functional inventory for each of the three dental auxiliary occupations (dental assisting, dental hygiene, and dental laboratory technology). The analysis consisted of…

  15. The effects of residual stress, viscoelastic and thermodynamic parameters on apparent fracture toughness of dental bilayer ceramic composites

    NASA Astrophysics Data System (ADS)

    Taskonak, Burak

    Bilayer dental ceramic composites used for fixed partial dentures are becoming more widely used in dental practices because of their biocompatibility, aesthetic properties, and chemical durability. However, large statistical variations in the strength of ceramics are associated with the structural flaws as a result of processing and complex stress states within the surfaces of the materials because of thermal properties of each layer. In addition, partial delaminations of the veneer layer and connector fractures of bilayer ceramic fixed partial dentures (FPDs) have been observed in a clinical study which is a part of this dissertation. Analysis of fracture surfaces of failed FPDs reveals that such fractures of the veneering ceramic are most likely caused by lateral crack growth. Global residual stresses associated with the coefficient of thermal expansion differences between core and veneering ceramics can cause lateral crack initiation. Also, rapid cooling of bilayer ceramics from the sintering temperature of the glass veneer may not allow the interfacial stresses in the viscoelastic glass to relax to equilibrium values. This can further contribute to the propagation of lateral cracks. Furthermore, local residual stresses that develop in the plastic deformation zone below sharp contact areas on the occlusal surface are another contributor to lateral crack growth. Superposition of global residual stresses and a Boussinesq stress field can incrementally increase the possibility of lateral crack growth. The long-range goals of this study are to critically analyze the lateral crack growth mechanisms associated with residual stresses, to modify residual tensile stress distributions by controlled heat treatment, and to minimize the probability of veneering ceramic fractures. Four approaches were used to accomplish these goals: (1) clinical evaluation of a bilayer ceramic fixed partial denture system; (2) fracture surface analysis of clinically failed FPDs; (3

  16. Electroless nickel plating on APTHS modified wood veneer for EMI shielding

    NASA Astrophysics Data System (ADS)

    Liu, Haibing; Li, Jian; Wang, Lijuan

    2010-12-01

    A new activation process was developed for electroless plating to prepare wood-based EMI shielding material. Pd(II) was adsorbed on a wood surface modified with γ-aminopropyltrihydroxysilane (APTHS) formed by the hydrolysis of γ-aminopropyltriethoxysilane (APTES). After reduction of Pd(II), electroless plating was successfully initiated and an Ni-P coating was deposited on the wood veneer. The activation process and resulting coating were characterized by XPS, SEM-EDS and XRD. The metal deposition, surface resistivity and electromagnetic shielding effectiveness were measured. XPS analysis proved that Pd(II) was bonded to the amino group of APTHS and was reduced to Pd(0). The Ni-P coating was uniform, compact and continuous, and consisted of 3.39 wt.% phosphorus and 96.61 wt.% nickel. XRD analysis indicated that the coating was crystalline, which is thought to be related to the low phosphorus content. The plated birch veneers exhibited electromagnetic shielding effectiveness greater than 60 dB in the frequency range 10 MHz-1.5 GHz.

  17. Tribocorrosion behavior of veneering biomedical PEEK to Ti6Al4V structures.

    PubMed

    Sampaio, Miguel; Buciumeanu, Mihaela; Henriques, Bruno; Silva, Filipe S; Souza, Júlio C M; Gomes, José R

    2016-02-01

    In dentistry, prosthetic structures must be able to support masticatory loads combined with a high biocompatibility and wear resistance in the presence of a corrosive environment. In order to improve the simultaneous wear and corrosion response of highly biocompatible prosthetic structures, a veneering poly-ether-ether-ketone (PEEK) to Ti6Al4V substrate was assessed by tribocorrosion analyses under conditions mimicking the oral environment. Samples were synthesized by hot pressing the PEEK veneer onto Ti6Al4V cylinders. The tribocorrosion tests on Ti6Al4V or PEEK/Ti6Al4V samples were performed on a reciprocating ball-on-plate tribometer at 30N normal load, 1Hz and stroke length of 3mm. The tests were carried out in artificial saliva at 37°C. Open circuit potential (OCP) was measured before, during and after reciprocating sliding tests. The worn surfaces were characterized by scanning electron microscopy. The results revealed a lower wear rate on PEEK combined with a lower coefficient of friction (COF), when compared to Ti6Al4V. In fact, PEEK protected Ti6Al4V substrate against the corrosive environment and wear avoiding the release of metallic ions to the surrounding environment.

  18. Reliability of Reduced-thickness and Thinly Veneered Lithium Disilicate Crowns

    PubMed Central

    Silva, N.R.F.A.; Bonfante, E.A.; Martins, L.M.; Valverde, G.B.; Thompson, V.P.; Ferencz, J.L.; Coelho, P.G.

    2012-01-01

    The present investigation hypothesized that the reliability of reduced-thickness monolithic lithium disilicate crowns is high relative to that of veneered zirconia (Y-TZP) and comparable with that of metal ceramic (MCR) systems. CAD/CAM first mandibular molar full-crown preparations were produced with uniform thicknesses of either 1.0-mm or 2.0-mm occlusal and axial reduction, then replicated in composite for standard crown dies. Monolithic 1.0-mm (MON) and 2.0-mm CAD/CAM lithium disilicate crowns, the latter with a buccal thin veneer (BTV) of 0.5 mm, were fabricated and then sliding-contact-fatigued (step-stress method) until failure or suspension (n = 18/group). Crack evolution was followed, and fractography of post mortem specimens was performed and compared with that of clinical specimens. Use level probability Weibull calculation (use load = 1,200 N) showed interval overlaps between MON and BTV. There was no significant difference between the Weibull characteristic failure loads of MON and BTV (1,535 N [90% CI 1,354–1,740] and 1,609 N [90% CI 1,512–1,712], respectively), which were significantly higher than that of Y-TZP (370 N [90% CI 322–427]) and comparable with that of MCR (1,304 N [90% CI 1,203–1,414]), validating the study hypothesis. PMID:22205635

  19. Strength and thickness of the layer of materials used for ceramic veneers bonding.

    PubMed

    Mazurek, Karolina; Mierzwińska-Nastalska, Elżbieta; Molak, Rafał; Kożuchowski, Mariusz; Pakieła, Zbigniew

    2012-01-01

    The use of adhesive bonding systems and composites in prosthetic dentistry brought improved and more aesthetic prosthetic restorations. The adhesive bonding of porcelain veneers is based on the micromechanical and chemical bond between tooth surface, cement layer and ceramic material. The aim of the study was to measure the thickness of the material layer formed during cementing of a ceramic restoration, and - in the second part of the study - to test tension of these cements. The materials investigated comprised dual-curing materials: Variolink II, KoNroot Cem, KoNroot Cem Viscous and Panavia F 2.0, as well as a light-curing composite: Variolink Veneer. The thickness was measured with the use of ZIP Lite 250 optical gauging apparatus. SEM microscope - Hitachi Tabletop Microscope TM-100 - was used to analyse the characteristics of an adhesive bond and filler particle size of particular materials. Tension tests of the cements under study were carried out on the MTS Q Test 10 static electrodynamic apparatus. The tests showed that KoNroot Cem exhibited the best mechanical properties of bonding to enamel and dentin among the materials tested. Variolink II base light-curing cement formed the thinnest layer. All the materials tested formed the layer not exceeding 1/3 of ceramic restoration thickness.

  20. Dental Exam for Children

    MedlinePlus

    ... and thumb sucking Toddlers, school-age children and adolescents During each regular checkup, the dentist or hygienist ... dental hygienist about proper oral health care for adolescents. American Dental Hygienists' Association. http://www.adha.org/ ...

  1. About Dental Amalgam Fillings

    MedlinePlus

    ... documents in the Related Resources section. Why is mercury used in dental amalgam? Approximately half of a ... about bioaccumulation, please see Related Resources. Is the mercury in dental amalgam the same as the mercury ...

  2. 75 FR 33169 - Dental Devices: Classification of Dental Amalgam, Reclassification of Dental Mercury, Designation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-11

    ...-AG21 Dental Devices: Classification of Dental Amalgam, Reclassification of Dental Mercury, Designation of Special Controls for Dental Amalgam, Mercury, and Amalgam Alloy; Technical Amendment AGENCY: Food... classified dental amalgam as a class II device, reclassified dental mercury from class I to class II,...

  3. Accreditation in Dental Hygiene.

    ERIC Educational Resources Information Center

    National Commission on Accrediting, Washington, DC.

    The Council on Dental Education cooperates with the American Dental Hygienists' Association in developing educational requirements for schools of dental hygiene. To be eligible for accreditation, schools must operate on a non-profit basis. A school applying for accreditation completes a previsitation questionnaire concerning its program. The…

  4. Dental Manpower Fact Book.

    ERIC Educational Resources Information Center

    Ake, James N.; Johnson, Donald W.

    Statistical data on many aspects of dental and allied dental personnel supply, distribution, characteristics, and education and on certain other aspects of dental services are presented and discussed. The data on dentist supply show the national trend in the supply of active dentists since 1950 and the concurrent changes in dentist-to-population…

  5. Dental Laboratory Technology.

    ERIC Educational Resources Information Center

    Department of the Air Force, Washington, DC.

    The Air Force dental laboratory technology manual is designed as a basic training text as well as a reference source for dental laboratory technicians, a specialty occupation concerned with the design, fabrication, and repair of dental prostheses. Numerous instructive diagrams and photographs are included throughout the manual. The comprehensive…

  6. DENTAL SCHOOL PLANNING.

    ERIC Educational Resources Information Center

    GALAGAN, DONALD J.

    THIS DISCUSSION PRESENTS A COMPLETE PICTURE OF THE CURRENT STATE OF DENTAL EDUCATION WITH SUGGESTIONS FOR MEETING THE DEMANDS FOR DENTAL STAFF AND FACILITIES. THE AREAS INVESTIGATED ARE (1) OBJECTIVES IN DENTAL EDUCATION--COURSES, TEACHING MODES, INNOVATIONS IN CURRICULUM, COORDINATION OF BASIC AND CLINICAL INSTRUCTION, (2) FACILITY…

  7. Dental Assisting Laboratory Manual.

    ERIC Educational Resources Information Center

    Thiel, Sandra J.

    Compiled to introduce the dental assisting student to various techniques used in the dental office and to present theoretical information essential for the student's professional development, this laboratory guide consists of three units of instruction. The first unit is an introduction to dental assisting and contains five topics of study. The…

  8. Perspectives from Dental Research.

    ERIC Educational Resources Information Center

    Baum, Bruce J.

    1996-01-01

    This paper responds to the Institute of Medicine's 1995 report concerning the present status and future needs of dental education in the United States. It examines whether real reform is occurring at the National Institute of Dental Research, within the academic dental community, and within the practicing profession. It concludes that very little…

  9. Weaker Dental Enamel Explains Dental Decay

    PubMed Central

    Vieira, Alexandre R.; Gibson, Carolyn W.; Deeley, Kathleen; Xue, Hui; Li, Yong

    2015-01-01

    Dental caries continues to be the most prevalent bacteria-mediated non-contagious disease of humankind. Dental professionals assert the disease can be explained by poor oral hygiene and a diet rich in sugars but this does not account for caries free individuals exposed to the same risk factors. In order to test the hypothesis that amount of amelogenin during enamel development can influence caries susceptibility, we generated multiple strains of mice with varying levels of available amelogenin during dental development. Mechanical tests showed that dental enamel developed with less amelogenin is “weaker” while the dental enamel of animals over-expressing amelogenin appears to be more resistant to acid dissolution. PMID:25885796

  10. Comparative evaluation of fracture resistance of Ceramic Veneer with three different incisal design preparations - An In-vitro Study

    PubMed Central

    Jankar, Ajit S; Kale, Yogesh; Kangane, Suresh; Ambekar, Anand; Sinha, Manish; Chaware, Sachin

    2014-01-01

    Background: Ceramic veneer fracture has occurred mainly at the incisal edge of the veneer because of greater stress. This study compares and evaluates the fracture resistance ceramic veneers with three different incisal preparations. Materials & Methods: 15 human permanent maxillary central incisor extracted were selected which were divided into three groups of 5 each having a different Incial design Preparation. Group 1: No Incisal reduction with facio- incisal bevel, Group 2 : 1 mm incisal reduction with butt joint, Group 3 : 1 mm incisal reduction with 1 mm height of Palatal chamfer. It was found that Group III had greater fracture resistance as compared to Group I and Group II. Group I had least fracture resistance as compared to Group II and III. Group II had greater fracture resistance as compared to Group I but less than Group III. Results: Ceramic veneer with 1mm incisal reduction with 1mm height of palatal chamfer showed highest fracture resistance as compared to 1mm incisal reduction with butt joint and no incisal reduction with facial-incisal bevel, in order to achieve better esthetic and functional results. Conclusion: The palatal chamfer margin results in preservation of some peripheral enamel layer, which eliminates the micro leakage at the palatal margin-restoration interface and also effectively counteracting shear stress. This design provides a definite seat for cementation. How to cite the article: Jankar AS, Kale Y, Kangane S, Ambekar A, Sinha M, Chaware S. Comparative evaluation of fracture resistance of Ceramic Veneer with three different incisal design preparations - An In-vitro Study. J Int Oral Health 2014;6(1):48-54. PMID:24653603

  11. Ceramic (Feldspathic & IPS Empress II) vs. laboratory composite (Gradia) veneers; a comparison between their shear bond strength to enamel; an in vitro study.

    PubMed

    Nikzad, S; Azari, Abbas; Dehgan, S

    2010-07-01

    Patient demand for aesthetic dentistry is steadily growing. Laminates and free metal restorations have evolved in an attempt to overcome the invasiveness nature of full veneer restorations. Although many different materials have been used for making these restorations, there is no single material that fits best for all purposes. Two groups of ceramic material (Feldspathic and IPS Empress II) and one group of laboratory composite (Gradia) discs (10 discs in each group; 4 mm in diameter and 2 mm in thickness) were prepared according to the manufacturer's instruction. The surface of ceramic discs were etched and silanized. In Gradia group, liquid primer was applied on composite surfaces. Thirty freshly extracted sound human molars and premolars were randomly divided into three groups. The enamel surface of each tooth was slightly flattened (0.3 mm) on the buccal or lingual side and then primed and cemented to the prepared discs with the aid of a dental surveyor. The finishing specimens were thermocycled between 5 degrees C and 55 degrees C for 2500 cycles and then prepared for shear bond strength testing. The resulting data were analyzed by one-way anova and Tukey HSD test. The fractured surfaces of each specimen were inspected by means of stereomicroscope and SEM. There is significant difference between the bond strength of materials tested. The mean bond strengths obtained with Feldspathic ceramic, IPS Empress II and Gradia were 33.10 +/- 4.31 MPa, 26.04 +/- 7.61 MPa and 14.42 +/- 5.82 MPa, respectively. The fracture pattern was mainly mixed for ceramic groups. More scientific evidence needed for standardization of bonding protocols.

  12. Evidence for an extracellular zinc-veneer in rodent brains from experiments with Zn-ionophores and ZnT3 knockouts.

    PubMed

    Nydegger, Irma; Rumschik, Sean M; Zhao, Jinfu; Kay, Alan R

    2012-10-17

    Ionic zinc is found at a high concentration in some glutamatergic vesicles of the mammalian brain. Ionic zinc is also found chelated to macromolecules in the extracellular space, constituting what has been called the "zinc veneer". In this communication we show that the zinc ionophore, pyrithione, can be used to demonstrate the presence of the veneer. Application of pyrithione without added ionic zinc to rodent hippocampal slices mobilizes extracellular zinc, which can be detected intracellularly by the zinc probe FluoZin-3. In addition, we show that ZnT3 null mice, which lack the transporter responsible for stocking synaptic vesicles, nevertheless do have a zinc veneer, albeit diminished compared to wild type animals. The presence of the zinc veneer in ZnT3 null mice may account for the absence of any marked deficit in these animals.

  13. Polyethylene ribbon and fixed orthodontic retention and porcelain veneers: solving an esthetic dilemma.

    PubMed

    Iniguez, I; Strassler, H E

    1998-01-01

    The patient, a 58-year-old woman, had started orthodontic treatment to correct spacing between the maxillary anterior teeth 6 year prior to presentation with a chief complaint of tooth discoloration and spacing. The treatment had consisted of the use of a removable appliance to retract the maxillary anterior teeth. The patient continued to wear the appliance sporadically. When she presented, the maxillary incisors were in primary occlusal trauma with Grade 2 mobility. The patient discontinued wearing the appliance. The periodontal condition was addressed with initial therapy. As part of the treatment plan to stabilize the maxillary anterior teeth and provide the patient with an esthetic result, it was decided to do a limited occlusal adjustment of the maxillary anterior teeth to control fremitus, and to place a fixed, composite resin, polyethylene ribbon-reinforced splint, using a facial approach. The esthetic restoration of these teeth was accomplished with bonded porcelain veneers.

  14. The effect of asbestos-alternatives on the accuracy of cast veneer crowns.

    PubMed

    Yli-Urpo, A; Oilo, G; Syverud, M

    1982-01-01

    The effect of three different lining materials on the investment expansion during the casting procedure, was compared. The accuracy of the castings was assessed by measuring slits at the gingival shoulder of a cast veneer crown. The liners were made of asbestosos, paper and a glassfiber material. They were used with a gypsum bonded and a phosphate bonded investment material using a regular type III and a high-fusing alloy. The glass-fiber material seemed to give a good and reproducible accuracy with both investments. The effect of this liner seemed to be comparable or better than that of the conventional asbest material. The paper liner sometimes allowed a sufficient expansion, but with varying results. Additional problems were connected to this material as it was burnt to ash during the mould heating procedure.

  15. Three years in vivo wear: core-ceramic, veneers, and enamel antagonists

    PubMed Central

    Esquivel-Upshaw, Josephine F.; Rose, William F.; Barrett, Allyson A.; Oliveira, Erica R.; Yang, Mark C.K.; Clark, Arthur E.; Anusavice, Kenneth J.

    2012-01-01

    Objectives Test the hypotheses that there are equivalent wear rates for enamel-versus-enamel and ceramic-versus-enamel, analyzing the in vivo wear of crown ceramics, their natural enamel antagonists, and the corresponding two contralateral teeth; and, that bite force does not correlate with the wear. Methods A controlled, clinical trial was conducted involving patients needing full coverage crowns opposing enamel antagonists. Bite forces were measured using a bilateral gnathodynamometer. Single-unit restorations of metal/ceramic (Argedent 62, Argen Corp/IPS d.SIGN veneer); or, core-ceramic/veneer from either, Empress2/Eris, or e.maxPress core/e.maxCeram glaze (ceramics: Ivoclar Vivadent, USA) were randomly assigned, fabricated and cemented. Impressions were made of the ceramic crowns, as well as each maxillary and mandibular quadrant at one week (baseline) and one, two and three years. Resulting models were scanned (3D laser scanner). Maximum wear was calculated by superimposing baseline with annual images. Results There were a total of thirty-six crowns required for thirty-one patients. Each restoration had three associated enamel teeth; 1) crown, 2) antagonist, 3) contralateral, and 4) contralateral-antagonist. SAS PROC MIXED (α=0.05) indicated no statistical significance for mean maximum wear among crown ceramics, enamel antagonists and contralaterals. However, enamel wear was statistically significant in relation to intraoral location (p=0.04) and among years (p<0.02). Analyzed alone, the enamel contralateral-antagonist exhibited significantly greater wear (p<0.001). Considering all wear sites, there was no correlation with bite force (p=0.15). Significance The ceramics and their antagonists exhibited in vivo wear rates within the range of normal enamel. Future studies should examine the wear implications of the contralateral-antagonist enamel. PMID:22410113

  16. Effect of provisional restorations on the final bond strengths of porcelain laminate veneers.

    PubMed

    Aykent, F; Usumez, A; Ozturk, A N; Yucel, M T

    2005-01-01

    The purpose of this in vitro study was to evaluate the effect of the different provisional restorations cementation techniques on the final bond strengths of porcelain laminate veneers (PLVs). Thirty-six extracted human central incisors were sectioned 2 mm below the cemento-enamel junction, and crown parts were embedded into self-cure acrylic resin. Standardized PLV preparations were carried out on labial surfaces of the teeth. Then the teeth were randomly divided into three groups of 12 each. In group 1, provisional restorations were cemented with eugenol-free cement. In group 2, prepared teeth surfaces were first coated with a desensitizing agent then provisional restorations were cemented with resin cement. In group 3, provisional restorations were not fabricated to serve as control. After specimens were stored in distilled water for 2 weeks, provisional restorations were removed and final IPS Empress 2 ceramic veneers were bonded with a dual-curing resin. Two microtensile samples from each tooth measuring 1.2 x 1.2 x 5 mm were prepared. These sections were subjected to microtensile testing and failure values were recorded. The data were analysed by one-way anova and Tukey HSD tests. The PLVs, placed on the tooth surface that had received a dentine desensitizer and provisional restorations luted with resin cement (group 2), showed the lowest bond strength in all test groups. But no statistically significant differences were found between the bond strength of PLVs in control group (no provisional restorations) and group 1 (provisional restorations cemented with eugenol-free cement before final cementations). Scanning electron microscopic (SEM) examination of this study also showed that the bonding to enamel surface was better in control group and group 1 than group 2.

  17. What is dental ecology?

    PubMed

    Cuozzo, Frank P; Sauther, Michelle L

    2012-06-01

    Teeth have long been used as indicators of primate ecology. Early work focused on the links between dental morphology, diet, and behavior, with more recent years emphasizing dental wear, microstructure, development, and biogeochemistry, to understand primate ecology. Our study of Lemur catta at the Beza Mahafaly Special Reserve, Madagascar, has revealed an unusual pattern of severe tooth wear and frequent tooth loss, primarily the result of consuming a fallback food for which these primates are not dentally adapted. Interpreting these data was only possible by combining our areas of expertise (dental anatomy [FC] and primate ecology [MS]). By integrating theoretical, methodological, and applied aspects of both areas of research, we adopted the term "dental ecology"-defined as the broad study of how teeth respond to the environment. Specifically, we view dental ecology as an interpretive framework using teeth as a vehicle for understanding an organism's ecology, which builds upon earlier work, but creates a new synthesis of anatomy and ecology that is only possible with detailed knowledge of living primates. This framework includes (1) identifying patterns of dental pathology and tooth use-wear, within the context of feeding ecology, behavior, habitat variation, and anthropogenic change, (2) assessing ways in which dental development and biogeochemical signals can reflect habitat, environmental change and/or stress, and (3) how dental microstructure and macro-morphology are adapted to, and reflect feeding ecology. Here we define dental ecology, provide a short summary of the development of this perspective, and place our new work into this context.

  18. Dental hygiene in Slovakia.

    PubMed

    Luciak-Donsberger, C; Krizanová, M

    2004-08-01

    This article reports on the development of the dental hygiene profession in Slovakia from a global perspective. The aim is to inform about current developments and to examine, how access to qualified dental hygiene care might be improved and how professional challenges might be met. For an international study on dental hygiene, secondary source data were obtained from members of the House of Delegates of the International Federation of Dental Hygienists (IFDH) or by fax and e-mail from experts involved in the national professional and educational organization of dental hygiene in non-IFDH member countries, such as Slovakia. Responses were followed-up by interviews, e-mail correspondence, visits to international universities, and a review of supporting studies and reference literature. Results show that the introduction of dental hygiene in Slovakia in 1992 was inspired by the delivery of preventive care in Switzerland. Initiating local dentists and dental hygienists strive to attain a high educational level, equitable to that of countries in which dental hygiene has an established tradition of high quality care. Low access to qualified dental hygiene care may be a result of insufficient funding for preventive services, social and cultural lack of awareness of the benefits of preventive care, and of limitations inherent in the legal constraints preventing unsupervised dental hygiene practice. These may be a result of gender politics affecting a female-dominated profession and of a perception that dental hygiene is auxiliary to dental care. International comparison show that of all Eastern European countries, the dental hygiene profession appears most advanced in Slovakia. This is expressed in high evidence-based academic goals, in extensive work with international consultants from the Netherlands and Switzerland, in annual congresses of high professional quality, and in the establishment of a profession, which has not been introduced in all Western EU countries.

  19. Effect of real time aging and cyclic fatigue on fused and cemented machined veneers to Y-TZP zirconia

    NASA Astrophysics Data System (ADS)

    Alhaddad, Abdulrahman Jafar M.

    Objectives: The objectives of this study was to determine the differences in failure load between cemented and fused machined veneers to zirconia while observing the effects of real time aging on failure load between cemented and fused machined veneers to zirconia. The study was to examine the differences in aging and fatigue resistance amongst a machined glass-ceramic veneer and a machined feldspathic porcelain veneer. Materials & Methods: VITA In Ceram YZ zirconia blocks were used as a substructure framework for the three unit fixed partial denture. The veneering material was either milled IPS e.max CAD (glass-ceramic) or milled VITABLOCS Triluxe Forte (feldspathic porcelain). The types of linking material between the substructures and veneering material were either fusing or cementation. Observations were compared between aged and non-aged specimens divided into two main groups; (a) non-aged group (b) aged for three years at room temperature. Each group has two subgroups; fused and cemented which are further divided into static and cyclic fatigue at 20K, 60K and 80K. Specimens were subjected to load to failure test using universal test machine. 40% of failure load was calculated for the cyclic fatigue subgroups. In order to examine the difference in failure load between the static and fatigued specimens, the Tukey-Kramer HSD test was used to analyze the data. Results and Conclusions: The VITABLOCS Triluxe Forte (feldspathic porcelain) fused to YZ zirconia showed significantly lower failure load values compared to all the other groups (p<0.05). The non-aged VITABLOCS Triluxe Forte cemented to YZ zirconia (static and cyclic) showed significantly higher load to failure than the aged cemented Triluxe fatigued groups (p<0.05). There is no significant difference in failure load between IPS e.max CAD fused and IPS e.max CAD cemented to YZ zirconia framework (p>0.05). The aged IPS e.max CAD fatigued (20K, 60K and 80K cycles) cemented to YZ zirconia showed lower

  20. Employment of Dental Hygienists as Dental Educators.

    ERIC Educational Resources Information Center

    Fong, Cynthia; Odrich, Johanna

    1987-01-01

    A study of the use of dental hygienists to teach periodontics, preventive dentistry, community dentistry, and public health courses looked at employment patterns and practices and the qualifications of the teachers. (MSE)

  1. Five-year clinical evaluation of 300 teeth restored with porcelain laminate veneers using total-etch and a modified self-etch adhesive system.

    PubMed

    Aykor, Arzu; Ozel, Emre

    2009-01-01

    This study evaluated the long-term clinical performance of porcelain laminate veneers luted with hybrid composite in combination with total-etch and self-etch adhesive systems. The study was performed on 30 patients ranging in age between 28 and 54 years. Ten veneers were performed per patient in the maxillary arch. In Group 1, 150 teeth were treated with porcelain veneers, using a total-etch adhesive system (Scotchbond Multi-Purpose Plus, 3M ESPE). In Group 2, 150 teeth were bonded with a self-etch adhesive system (AdheSE, Ivoclar-Vivadent). All the veneers were luted with a light-cured hybrid composite (Z100, 3M ESPE). The patients were recalled after 1, 2 and 5 years. Modified United States Public Health Service (USPHS) criteria were utilized to evaluate the porcelain laminate veneers in terms of marginal adaptation, cavo-surface marginal discoloration, secondary caries, postoperative sensitivity, satisfaction with restoration shade and gingival tissue response. Data were analyzed using the Chi-Square test (p < 0.05). There was no statistically significant difference between the total-etch and self-etch groups in terms of USPHS criteria (p > 0.05). Porcelain veneers exhibited successful clinical performance with both total-etch and two-step self-etch adhesives at the end of five-years.

  2. Pathways in dental public health.

    PubMed

    Silverstein, Steven J

    2005-07-01

    Dental public health is one of the nine specialties of dentistry recognized by the American Dental Association Commission on Dental Accreditation. Dental public health has been defined as the "science and art of preventing and controlling dental diseases and promoting dental health through organized community efforts. It is that form of dental practice which serves the community as a patient rather than as an individual. It is concerned with the dental health education of the public, with applied dental research, and with the administration of group dental care programs as well as the prevention and control of dental diseases on a community basis." This article will describe the many career and educational pathways dentists may follow to become irvolved in the practice of dental public health.

  3. International dental standards.

    PubMed

    Jones, Derek W

    2007-09-22

    International dental standards are vital in maintaining the safety and quality of both the products and materials used by dental professionals and the many oral health products used by members of the general public, yet many dentists will be unaware of the role standards play in their daily practice. In this article, Derek W. Jones outlines the vital work of the International Standards Organization and highlights how standards pervade nearly every dental procedure.

  4. Dental radiology for children

    SciTech Connect

    Myers, D.R.

    1984-01-01

    The benefit for the child from the judicious use of diagnostic dental radiography is improved dental health. The risk to the child from dental diagnostic radiation exposure appears to be extremely low. Despite the low risk, the dentist must minimize the child's exposure to ionizing radiation by using sound clinical judgment to determine what radiographs are necessary and to provide children with optimal protection from ionizing radiation.

  5. Dental erosion, summary.

    PubMed

    ten Cate, J M; Imfeld, T

    1996-04-01

    Although reports on dental erosion have always appeared in the dental literature, there is currently a growing interest among researchers and clinicians. Potential risk factors for dental erosion are changed lifestyle and eating patterns, with increased consumption of acidic foods and beverages. Various gastrointestinal and eating disorders expose the dentition to frequent contacts with very acidic gastric content, which may lead to erosion. Whether these factors indeed lead, on a population scale, to a higher prevalence and incidence of erosion is yet to be established. This article summarizes the different aspects of the prevalence, pathology, etiology, assessment, prevention and treatment of dental erosion, and concludes with recommendations for future research.

  6. Dental Implant Systems

    PubMed Central

    Oshida, Yoshiki; Tuna, Elif B.; Aktören, Oya; Gençay, Koray

    2010-01-01

    Among various dental materials and their successful applications, a dental implant is a good example of the integrated system of science and technology involved in multiple disciplines including surface chemistry and physics, biomechanics, from macro-scale to nano-scale manufacturing technologies and surface engineering. As many other dental materials and devices, there are crucial requirements taken upon on dental implants systems, since surface of dental implants is directly in contact with vital hard/soft tissue and is subjected to chemical as well as mechanical bio-environments. Such requirements should, at least, include biological compatibility, mechanical compatibility, and morphological compatibility to surrounding vital tissues. In this review, based on carefully selected about 500 published articles, these requirements plus MRI compatibility are firstly reviewed, followed by surface texturing methods in details. Normally dental implants are placed to lost tooth/teeth location(s) in adult patients whose skeleton and bony growth have already completed. However, there are some controversial issues for placing dental implants in growing patients. This point has been, in most of dental articles, overlooked. This review, therefore, throws a deliberate sight on this point. Concluding this review, we are proposing a novel implant system that integrates materials science and up-dated surface technology to improve dental implant systems exhibiting bio- and mechano-functionalities. PMID:20480036

  7. Randomized Clinical Trial of Implant-Supported Ceramic-Ceramic and Metal-Ceramic Fixed Dental Prostheses: Preliminary Results

    PubMed Central

    Esquivel-Upshaw, Josephine F.; Clark, Arthur E.; Shuster, Jonathan J.; Anusavice, Kenneth J.

    2013-01-01

    Purpose The aim of this study was to determine the survival rates over time of implant-supported ceramic-ceramic and metal-ceramic prostheses as a function of core-veneer thickness ratio, gingival connector embrasure design, and connector height. Materials and Methods An IRB-approved, randomized, controlled clinical trial was conducted as a single-blind pilot study involving 55 patients missing three teeth in either one or two posterior areas. These patients (34 women; 21 men; age range 52–75 years) were recruited for the study to receive a 3-unit implant-supported fixed dental prosthesis (FDP). Two implants were placed for each of the 72 FDPs in the study. The implants (Osseospeed, Astra Tech), which were made of titanium, were grit blasted. A gold-shaded, custom-milled titanium abutment (Atlantis, Astra Tech), was secured to each implant body. Each of the 72 FDPs in 55 patients were randomly assigned based on one of the following options: (1) A. Material: ceramic-ceramic (Yttria-stabilized zirconia core, pressable fluorapatite glass-ceramic, IPS e.max ZirCAD and ZirPress, Ivoclar Vivadent) B. metal-ceramic (palladium-based noble alloy, Capricorn, Ivoclar Vivadent, with press-on leucite-reinforced glass-ceramic veneer, IPS InLine POM, Ivoclar Vivadent); (2) occlusal veneer thickness (0.5, 1.0, and 1.5 mm); (3) curvature of gingival embrasure (0.25, 0.5, and 0.75 mm diameter); and (4) connector height (3, 4, and 5 mm). FDPs were fabricated and cemented with dual-cure resin cement (RelyX, Universal Cement, 3M ESPE). Patients were recalled at 6 months, 1 year, and 2 years. FDPs were examined for cracks, fracture, and general surface quality. Results Recall exams of 72 prostheses revealed 10 chipping fractures. No fractures occurred within the connector or embrasure areas. Two-sided Fisher’s exact tests showed no significant correlation between fractures and type of material system (p = 0.51), veneer thickness (p = 0.75), radius of curvature of gingival embrasure

  8. Ratios of S, Se and Te in the silicate Earth require a volatile-rich late veneer.

    PubMed

    Wang, Zaicong; Becker, Harry

    2013-07-18

    The excess of highly siderophile (iron-loving) elements (HSEs) and the chondritic ratios of most HSEs in the bulk silicate Earth (BSE) may reflect the accretion of a chondritic 'late veneer' of about 0.5 per cent of Earth's mass after core formation. The amount of volatiles contained in the late veneer is a key constraint on the budget and the origin of the volatiles in Earth. At high pressures and temperatures, the moderately volatile chalcogen elements sulphur (S), selenium (Se) and tellurium (Te) are moderately to highly siderophile; thus, if depleted by core formation their mantle abundances should reflect the volatile composition of the late veneer. Here we report ratios and abundances of S, Se and Te in the mantle determined from new isotope dilution data for post-Archaean mantle peridotites. The mean S/Se and Se/Te ratios of mantle lherzolites overlap with CI (Ivuna-type) carbonaceous chondrite values. The Se/Te ratios of ordinary and enstatite chondrites are significantly different. The chalcogen/HSE ratio of the BSE is similar to that of CM (Mighei-type) carbonaceous chondrites, consistent with the view that the HSE signature of the BSE reflects a predominance of slightly volatile-depleted, carbonaceous-chondrite-like material, possibly with a minor proportion of non-chondritic material. Depending on the estimates for the abundances of water and carbon in the BSE, the late veneer may have supplied 20 to 100 per cent of the budget of hydrogen and carbon in the BSE.

  9. Investigation of the time-dependent wear behavior of veneering ceramic in porcelain fused to metal crowns during chewing simulations.

    PubMed

    Guo, Jiawen; Tian, Beimin; Wei, Ran; Wang, Weiguo; Zhang, Hongyun; Wu, Xiaohong; He, Lin; Zhang, Shaofeng

    2014-12-01

    The excessive abrasion of occlusal surfaces in ceramic crowns limits the service life of restorations and their clinical results. However, little is known about the time-dependent wear behavior of ceramic restorations during the chewing process. The aim of this in vitro study was to investigate the dynamic evolution of the wear behavior of veneering porcelain in PFM crowns as wear progressed, as tested in a chewing simulator. Twenty anatomical metal-ceramic crowns were prepared using Ceramco III as the veneering porcelain. Stainless steel balls served as antagonists. The specimens were dynamically loaded in a chewing simulator with 350N up to 2.4×10(6) loading cycles, with additional thermal cycling between 5 and 55°C. During the testing, several checkpoints were applied to measure the substance loss of the crowns' occlusal surfaces and to evaluate the microstructure of the worn areas. After 2.4×10(6) cycles, the entire wear process of the veneering porcelain in the PFM crowns revealed three wear stages (running-in, steady and severe wear stages). The occlusal surfaces showed traces of intensive wear on the worn areas during the running-in wear stage, and they exhibited the propagation of cracks in the subsurface during steady wear stage. When the severe wear stage was reached, the cracks penetrated the ceramic layer, causing the separation of porcelain pieces. It also exhibited a good correlation among the microstructure, the wear loss and the wear rate of worn ceramic restorations. The results suggest that under the conditions of simulated masticatory movement, the wear performance of the veneering porcelain in PFM crowns indicates the apparent similarity of the tribological characteristics of the traditional mechanical system. Additionally, the evaluation of the wear behavior of ceramic restorations should be based on these three wear stages.

  10. The effect of melt infiltration of borosilicate glass on biaxial flexural strength of porcelain-veneered zirconia

    NASA Astrophysics Data System (ADS)

    Joo, Kyu Ji; Song, Kyung Woo; Jung, Jong Hyun; Ahn, Hyo Jin; Park, Il Song; Lee, Min Ho; Bae, Tae Sung

    2011-08-01

    To evaluate the effect of melt infiltration on the biaxial flexural strength of porcelain-bonded zirconia, borosilicate glasses were used in this study. Presintered yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) blocks were milled and used for disc specimens. Prior to veneering of porcelain, the infiltration of borosilicate glass on zirconia was performed at 1,100 °C for 1 h. After a biaxial flexural test with the crosshead speed of 0.1 mm/min, fractured surfaces and interfaces between zirconia and veneer porcelain were observed with a Scanning Electron Microscope (SEM). The fracture strength of sintered zirconia and veneer porcelain was significantly increased by the melt infiltration of borosilicate glass (P < 0.05). The melt infiltration process of borosilicate glass greatly improved the Weibull modulus of sintered zirconia. However, the Weibull modulus of porcelain increased slightly. The sintered zirconia group showed a smooth fracture surface containing many pores, but the glass-infiltrated zirconia group showed a rough fracture surface.

  11. Redistribution of Lunar Polar Water to Mid-latitudes and its Role in Forming an OH veneer - Revisited

    NASA Technical Reports Server (NTRS)

    Farrell, W. M.; Killen, R. M.; Hurley, D. M.; Hodges, R. R.; Halekas, J. S.; Delory, G. T.

    2012-01-01

    We suggest that energization processes like ion sputtering and impact vaporization can eject/release polar water molecules residing within lunar cold trapped regions with sufficient velocity to allow their redistribution to mid-latitudes. We consider the possibility that these polar-ejected molecules can be an additional (but not dominant) contribution to the water/OH veneer observed as a 3 micron absorption feature at mid-latitudes by Chandrayaan-I, Cassini, and EPOXI. Taking the conservative case that polar water is ejected only from the floor of polar craters with an 0.1 % icy regolith then overall source rates are near 10(exp 18) H20s/s. This outflow amounts to approx 10(exp -7) kg/s of water to be ejected from each pole and is a water source rate that is 10(exp .5 lower than the overall exospheric source rate for all species. Hence, the out-flowing polar water is a perturbation in the overall exosphere composition & dynamics. This polar water 'fountain' model may not fully account for the relatively high concentrations in the mid-latitude water veneer observed in the IR (approx 10-1000 ppm). However, it may account for some part of the veneer. We note that the polar water fountain source rates scale linearly with ice concentration, and larger mass fractions of polar crater water should provide correspondingly larger fractions of water emission out of the poles which then 'spills' on to mid-latitude surfaces.

  12. The influence of various core designs on stress distribution in the veneered zirconia crown: a finite element analysis study

    PubMed Central

    Ha, Seung-Ryong; Kim, Sung-Hun; Yoo, Seung-Hyun; Jeong, Se-Chul; Lee, Jai-Bong; Yeo, In-Sung

    2013-01-01

    PURPOSE The purpose of this study was to evaluate various core designs on stress distribution within zirconia crowns. MATERIALS AND METHODS Three-dimensional finite element models, representing mandibular molars, comprising a prepared tooth, cement layer, zirconia core, and veneer porcelain were designed by computer software. The shoulder (1 mm in width) variations in core were incremental increases of 1 mm, 2 mm and 3 mm in proximal and lingual height, and buccal height respectively. To simulate masticatory force, loads of 280 N were applied from three directions (vertical, at a 45° angle, and horizontal). To simulate maximum bite force, a load of 700 N was applied vertically to the crowns. Maximum principal stress (MPS) was determined for each model, loading condition, and position. RESULTS In the maximum bite force simulation test, the MPSs on all crowns observed around the shoulder region and loading points. The compressive stresses were located in the shoulder region of the veneer-zirconia interface and at the occlusal region. In the test simulating masticatory force, the MPS was concentrated around the loading points, and the compressive stresses were located at the 3 mm height lingual shoulder region, when the load was applied horizontally. MPS increased in the shoulder region as the shoulder height increased. CONCLUSION This study suggested that reinforced shoulder play an essential role in the success of the zirconia restoration, and veneer fracture due to occlusal loading can be prevented by proper core design, such as shoulder. PMID:23755346

  13. Education About Dental Hygienists' Roles in Public Dental Prevention Programs: Dental and Dental Hygiene Students' and Faculty Members' and Dental Hygienists' Perspectives.

    PubMed

    Pervez, Anushey; Kinney, Janet S; Gwozdek, Anne; Farrell, Christine M; Inglehart, Marita R

    2016-09-01

    In 2005, Public Act No. 161 (PA 161) was passed in Michigan, allowing dental hygienists to practice in approved public dental prevention programs to provide services for underserved populations while utilizing a collaborative agreement with a supervising dentist. The aims of this study were to assess how well dental and dental hygiene students and faculty members and practicing dental hygienists have been educated about PA 161, what attitudes and knowledge about the act they have, and how interested they are in additional education about it. University of Michigan dental and dental hygiene students and faculty members, students in other Michigan dental hygiene programs, and dental hygienists in the state were surveyed. Respondents (response rate) were 160 dental students (50%), 63 dental hygiene students (82%), 30 dental faculty members (26%), and 12 dental hygiene faculty members (52%) at the University of Michigan; 143 dental hygiene students in other programs (20%); and 95 members of the Michigan Dental Hygienists' Association (10%). The results showed that the dental students were less educated about PA 161 than the dental hygiene students, and the dental faculty members were less informed than the dental hygiene faculty members and dental hygienists. Responding dental hygiene faculty members and dental hygienists had more positive attitudes about PA 161 than did the students and dental faculty members. Most of the dental hygiene faculty members and dental hygienists knew a person providing services in a PA 161 program. Most dental hygiene students, faculty members, and dental hygienists wanted more education about PA 161. Overall, the better educated about the program the respondents were, the more positive their attitudes, and the more interested they were in learning more.

  14. Influence of the fabrication process on the in vitro performance of fixed dental prostheses with zirconia substructures.

    PubMed

    Rosentritt, Martin; Kolbeck, Carola; Handel, Gerhard; Schneider-Feyrer, Sibylle; Behr, Michael

    2011-12-01

    Chipping of the applied veneering ceramic is reported to be a main clinical failure type of computer-aided design/computer-aided manufacturing- or manually copy-milled zirconia restorations. The aim of this in vitro study was to investigate whether different substructure designs and veneering processes done by different dental technicians do significantly influence chipping in zirconia-based all-ceramic fixed dental prostheses during simulated oral service. Five groups (n = 8 per group) of three-unit zirconia substructures were fabricated in three different laboratories using copy-milling technique. Three series were veneered with identical porcelain (groups 1-3) and one with a second different porcelain (group 4). The fifth group was milled to final contour design without veneering. Dimensions of the connector areas were determined. All fixed partial dentures (FPDs) were adhesively boned on human teeth and thermally cycled and mechanically loaded (1.2 × 10(6) × 50 N; 6,000 × 5°C/55°C) using human antagonists. Restorations were monitored during thermal cycling and mechanical loading (TCML). FPDs which survived were loaded to fracture. FPDs which failed during TCML were investigated with fractographic means. During TCML, chipping took place in groups 1 (two times), 2 (four times) and 3 (five times) (Table 1). Chipping areas varied between 2.3 mm(2) (group 3) and 58.7 mm(2) (group 2). Groups 4 and 5 provided no failures during TCML. Failure in all cases started from contact points, where superficial wear and disruption of the porcelain were found. No significant correlation could be determined between connector thickness and number of failures. Median fracture results varied between 1,011 N (group 3) and 2,126 N (group 2). The results show the necessity of considering individual design and manufacturing of restorations as well as contact situation. Advanced technical training on zirconia-based restorations is recommended.

  15. Dental Laboratory Technician.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Center on Education and Training for Employment.

    This document, which is designed for use in developing a tech prep competency profile for the occupation of dental laboratory technician, lists technical competencies and competency builders for 13 units pertinent to the health technologies cluster in general and 8 units to the occupation of dental laboratory technician. The following skill areas…

  16. Dental Assisting Program Guide.

    ERIC Educational Resources Information Center

    Georgia Univ., Athens. Dept. of Vocational Education.

    This program guide contains the standard dental assisting curriculum for technical institutes in Georgia. The curriculum encompasses the minimum competencies required for entry-level dental assistants, and includes job skills in the technical areas of preventive dentistry; four-handed dentistry; chairside assisting with emphasis in diagnostics,…

  17. Clinical feline dental radiography.

    PubMed

    Lemmons, Matthew

    2013-05-01

    Dental radiography is a necessary diagnostic modality in small animal practice. It is not possible to accurately assess and diagnose tooth resorption, periodontal disease, endodontic disease, neoplasia and injury without it. Dental radiography is also necessary for treatment and assessment of the patient postoperatively.

  18. Dental Charting. Student's Manual.

    ERIC Educational Resources Information Center

    Weaver, Trudy Karlene; Apfel, Maura

    This manual is part of a series dealing with skills and information needed by students in dental assisting. The individualized student materials are suitable for classroom, laboratory, or cooperative training programs. This student manual contains four units covering the following topics: dental anatomical terminology; tooth numbering systems;…

  19. Workbook for Dental Records.

    ERIC Educational Resources Information Center

    Carpenter, Corinne K.; Volpe, Margaret E.

    This workbook contains l8 units of instruction for dental assistant students, each designed to give students practical experience in completing forms that simulate realistic situations in a dental office. Units are: (1) The Appointment Record, (2) The Recall System, (3) Clinical Records, (4) Estimates, (5) Daily Record Sheet, (6) Patient's…

  20. CO2 Laser Glazing Treatment of a Veneering Porcelain: Effects on Porosity, Translucency, and Mechanical Properties.

    PubMed

    Sgura, R; dos Reis, M C; Salvadori, M C; Hernandes, A C; Cesar, P F; Medeiros, I S

    2015-01-01

    This work tested CO2 laser as a glazing agent and investigated the effects of irradiation on the porosity, translucency, and mechanical properties of veneering porcelain. Sixty discs (diameter 3.5 × 2.0 mm) of veneering porcelain for Y-TZP frameworks (VM9, VITA Zahnfabrik) were sintered and had one of their faces mirror polished. The specimens were divided into six groups (n=10/group) according to surface treatment, as follows: no treatment-control; auto-glaze in furnace following manufacturer's instructions (G); and CO2 laser (45 or 50 W/cm(2)) applied for four or five minutes (L45/4, L45/5, L50/4, L50/5). Optical microscopy (Shimadzu, 100×) was conducted and the images were analyzed with Image J software for the determination of the following porosity parameters: area fraction, average size, and Feret diameter. The translucency parameter studied was masking ability, determined by color difference (ΔE) over black and white backgrounds (CM3370d, Konica Minolta). Microhardness and fracture toughness (indentation fracture) were measured with a Vickers indenter (HMV, Shimadzu). Contact atomic force microscopy (AFM) (50 × 50 μm(2), Nanoscope IIIA, Veeco) was performed at the center of one sample from each group, except in the case of L45/5. With regard to porosity and translucency parameters, auto-glazed and laser-irradiated specimens presented statistical similarity. The area fraction of the surface pores ranged between 2.4% and 5.4% for irradiated specimens. Group L50/5 presented higher microhardness when compared to the G group. The higher (1.1) and lower (0.8) values for fracture toughness (MPa.m(1/2)) were found in laser-irradiated groups (L50/4 and L45/4, respectively). AFM performed after laser treatment revealed changes in porcelain surface profile at a submicrometric scale, with the presence of elongated peaks and deep valleys.

  1. Bond strength of veneer ceramic and zirconia cores with different surface modifications after microwave sintering

    PubMed Central

    Saka, Muhammet

    2013-01-01

    PURPOSE To evaluate the effects of surface treatments on shear bond strength (SBS) between microwave and conventionally sintered zirconia core/veneers. MATERIALS AND METHODS 96 disc shaped Noritake Alliance zirconia specimens were fabricated using YenaDent CAM unit and were divided in 2 groups with respect to microwave or conventional methods (n=48/group). Surface roughness (Ra) evaluation was made with a profilometer on randomly selected microwave (n=10) and conventionally sintered (n=10) cores. Specimens were then assessed into 4 subgroups according to surface treatments applied (n=12/group). Groups for microwave (M) and conventionally (C) sintered core specimens were as follows; MC,CC: untreated (control group), M1,C1:Al2O3 sandblasting, M2,C2:liner, M3,C3:Al2O3 sandblasting followed by liner. Veneer ceramic was fired on zirconia cores and specimens were thermocycled (6000 cycles between 5°-55℃). All specimens were subjected to SBS test using a universal testing machine at 0.5 mm/min, failure were evaluated under an optical microscope. Data were statistically analyzed using Shapiro Wilk, Levene, Post-hoc Tukey HSD and Student's t tests, Two-Way-Variance-Analysis and One-Way-Variance-Analysis (α=.05). RESULTS Conventionally sintered specimens (1.06 ± 0.32 µm) showed rougher surfaces compared to microwave sintered ones (0.76 ± 0.32 µm)(P=.046), however, no correlation was found between SBS and surface roughness (r=-0.109, P=.658). The statistical comparison of the shear bond strengths of C3 and C1 group (P=.015); CC and MC group (P=.004) and C3 and M3 group presented statistically higher (P=.005) values. While adhesive failure was not seen in any of the groups, cohesive and combined patterns were seen in all groups. CONCLUSION Based on the results of this in-vitro study, Al2O3- sandblasting followed by liner application on conventionally sintered zirconia cores may be preferred to enhance bond strength. PMID:24353890

  2. Dental Fear Among University Employees: Implications for Dental Education.

    ERIC Educational Resources Information Center

    Kaakko, Tarja; Milgrom, Peter; Coldwell, Susan E.; Getz, Tracy; Weinstein, Philip; Ramsay, Douglas S.

    1998-01-01

    A survey of 270 University of Washington permanent employees who were potential candidates for teaching clinics, found dental anxiety prevalent, correlating with poorer perceived dental health, longer intervals between dental appointments, higher frequency of past fear behaviors, more physical symptoms during last dental injection, and more…

  3. Mechanochemically synthesized kalsilite based bioactive glass-ceramic composite for dental vaneering

    NASA Astrophysics Data System (ADS)

    Kumar, Pattem Hemanth; Singh, Vinay Kumar; Kumar, Pradeep

    2015-08-01

    Kalsilite glass-ceramic composites have been prepared by a mechanochemical synthesis process for dental veneering application. The aim of the present study is to prepare bioactive kalsilite composite material for application in tissue attachment and sealing of the marginal gap between fixed prosthesis and tooth. Mechanochemical synthesis is used for the preparation of microfine kalsilite glass-ceramic. Low temperature frit and bioglass have been prepared using the traditional quench method. Thermal, microstructural and bioactive properties of the composite material have been examined. The feasibility of the kalsilite to be coated on the base commercial opaque as well as the bioactive behavior of the coated specimen has been confirmed. This study indicates that the prepared kalsilite-based composites show similar structural, morphological and bioactive behavior to that of commercial VITA VMK95 Dentin 1M2.

  4. [The impact of ultrasonic dental hygiene procedures on the bonding strength of restorations].

    PubMed

    Kuznetsov, D L; Mel'nik, A A; Laze, R; Petrikas, O A; Petrikas, I V

    2013-01-01

    Ultrasonic calculus scaling has become a common oral hygiene procedure in patients with composite restorations, dental veneers, orthodontic brackets. The aim of the study was to evaluate in vitro the influence of the EMS-ultrasonic system scaling on the flowable composite bond strength to the tooth enamel, dentine, and e-max ceramic. The samples were divided into three groups: 1 group (composite bonded to enamel), 2 group (composite bonded to dentine), 3 group (composite bonded to e-max ceramic). The bonded samples were loaded to failure in the universal testing machine. The shear bond strength was calculated in newtons (N). T (Student's)-test was used to evaluate the data. Significantly lower bond strengths were observed with the ultrasonic treated samples in each groups. The EMS-ultrasonic system scaling significantly decreases the flowable composite bond strength to the tooth enamel, dentine, and e-max ceramic.

  5. Inlay-retained zirconia fixed dental prosthesis: clinical and laboratory procedures.

    PubMed

    Monaco, Carlo; Cardelli, Paolo; Bolognesi, Michele; Scotti, Roberto; Ozcan, Mutlu

    2012-01-01

    Many treatment options are currently available for single tooth replacement, such as metal-ceramic, all-ceramic, direct or indirect fiber-reinforced composite fixed dental prostheses (FDPs) or implants. Inlay-retained FDPs could be indicated especially when adjacent teeth have preexisting restorations and where implant placement is not possible or not indicated. In such cases, indication of both metal-ceramic and fiber-reinforced composite FDPs has certain disadvantages. This paper describes the use of all-ceramic inlay-retained FDPs with zirconia frameworks, veneered with a press-on technique. The retainer margins were made of pressed ceramic to make adhesive luting possible. In deep cavities, a full contour press-on ceramic all around the retainers increased the available surface area for the adhesive approach.

  6. Special cluster issue on tribocorrosion of dental materials

    NASA Astrophysics Data System (ADS)

    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

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

    ERIC Educational Resources Information Center

    Lind, Patricia; Germano, Catherine

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

  8. Effect of veneering materials and curing methods on resin cement knoop hardness.

    PubMed

    Tango, Rubens Nisie; Sinhoreti, Mário Alexandre Coelho; Correr, Américo Bortolazzo; Correr-Sobrinho, Lourenço; Consani, Rafael Leonardo Xediek

    2007-01-01

    This study evaluated the Knoop hardness of Enforce resin cement activated by the either chemical/physical or physical mode, and light cured directly and through ceramic (HeraCeram) or composite resin (Artglass). Light curing were performed with either conventional halogen light (QTH; XL2500) for 40 s or xenon plasma arc (PAC; Apollo 95E) for 3 s. Bovine incisors had their buccal surfaces flattened and hybridized. On these surfaces a mold was seated and filled with cement. A 1.5-mm-thick disc of the veneering material was seated over this set for light curing. After storage (24 h/37 masculineC), specimens (n=10) were sectioned for hardness (KHN) measurements in a micro-hardness tester (50 gf load/ 15 s). Data were submitted to ANOVA and Tukey's test (alpha=0.05). It was observed that the dual cure mode yielded higher hardness compared to the physical mode alone, except for direct light curing with the QTH unit and through Artglass. Higher hardness was observed with QTH compared to PAC, except for Artglass/dual groups, in which similar hardness means were obtained. Low KHN means were obtained with PAC for both Artglass and HeraCeram. It may be concluded that the hardness of resin cements may be influenced by the presence of an indirect restorative material and the type of light-curing unit.

  9. The effects of different shades of resin luting cement on the color of ceramic veneers.

    PubMed

    Alqahtani, Mohammed Q; Aljurais, Rana M; Alshaafi, Maan M

    2012-01-01

    The purpose of this study was to quantitatively evaluate the effects of different shades of light-polymerized resin cement on the color of two different thicknesses (0.5 mm and 0.7 mm) of three different ceramic materials (Esthetic, e.max, and ZirPress). A spectrophotometer (Color Eye 7000A - CIE (L*a*b*) was used to measure the color of specimens on the control substrate without cement, and then on (Translucent, White Opaque, B0.5, A1, and A3 of RelyX™ Veneer cement). The mean values of color difference (ΔE) were higher for Esthetic, followed by ZirPress, with the lowest values for e.max. The mean values of ΔE decreased when the thickness of ceramic increased from 0.5 mm to 0.7 mm. It was observed that the White Opaque had significantly increased ΔE values when compared with (TR, B0.5, A1, and A3), whereas no significant difference between B0.5 and TR, and between B0.5 and A3.

  10. Improved performance of diatomite-based dental nanocomposite ceramics using layer-by-layer assembly.

    PubMed

    Lu, Xiaoli; Xia, Yang; Liu, Mei; Qian, Yunzhu; Zhou, Xuefeng; Gu, Ning; Zhang, Feimin

    2012-01-01

    To fabricate high-strength diatomite-based ceramics for dental applications, the layer-by-layer technique was used to coat diatomite particles with cationic [poly(allylamine hydrochloride)] and anionic [poly(sodium 4-styrenesulfonate)] polymers to improve the dispersion and adsorption of positively charged nano-ZrO(2) (zirconia) as a reinforcing agent. The modified diatomite particles had reduced particle size, narrower size distribution, and were well dispersed, with good adsorption of nano-ZrO(2). To determine the optimum addition levels for nano-ZrO(2), ceramics containing 0, 20, 25, 30, and 35 wt% nano-ZrO(2) were sintered and characterized by the three-point bending test and microhardness test. In addition to scanning electron microscopy, propagation phase-contrast synchrotron X-ray microtomography was used to examine the internal structure of the ceramics. The addition of 30 wt% nano-ZrO(2) resulted in the highest flexural strength and fracture toughness with reduced porosity. Shear bond strength between the core and veneer of our diatomite ceramics and the most widely used dental ceramics were compared; the shear bond strength value for the diatomite-based ceramics was found to be significantly higher than for other groups (P < 0.05). Our results show that diatomite-based nanocomposite ceramics are good potential candidates for ceramic-based dental materials.

  11. Improved performance of diatomite-based dental nanocomposite ceramics using layer-by-layer assembly

    PubMed Central

    Lu, Xiaoli; Xia, Yang; Liu, Mei; Qian, Yunzhu; Zhou, Xuefeng; Gu, Ning; Zhang, Feimin

    2012-01-01

    To fabricate high-strength diatomite-based ceramics for dental applications, the layer-by-layer technique was used to coat diatomite particles with cationic [poly(allylamine hydrochloride)] and anionic [poly(sodium 4-styrenesulfonate)] polymers to improve the dispersion and adsorption of positively charged nano-ZrO2 (zirconia) as a reinforcing agent. The modified diatomite particles had reduced particle size, narrower size distribution, and were well dispersed, with good adsorption of nano-ZrO2. To determine the optimum addition levels for nano-ZrO2, ceramics containing 0, 20, 25, 30, and 35 wt% nano-ZrO2 were sintered and characterized by the three-point bending test and microhardness test. In addition to scanning electron microscopy, propagation phase-contrast synchrotron X-ray microtomography was used to examine the internal structure of the ceramics. The addition of 30 wt% nano-ZrO2 resulted in the highest flexural strength and fracture toughness with reduced porosity. Shear bond strength between the core and veneer of our diatomite ceramics and the most widely used dental ceramics were compared; the shear bond strength value for the diatomite-based ceramics was found to be significantly higher than for other groups (P < 0.05). Our results show that diatomite-based nanocomposite ceramics are good potential candidates for ceramic-based dental materials. PMID:22619551

  12. Minimally invasive prosthetic procedures in the rehabilitation of a bulimic patient affected by dental erosion

    PubMed Central

    Derchi, Giacomo; Peñarrocha, David; Barone, Antonio; Covani, Ugo

    2015-01-01

    The population affected by dental erosion due to bulimia is generally very young. This population group has a high aesthetic requirement; the dentition in these patients is severely damaged, especially in the anterior maxillary quadrant. In terms of treatment, it is still controversial whether an adhesive rehabilitation is preferable to a longer-lasting but more aggressive conventional treatment, such as full-crown coverage of the majority of teeth. This case report describes the prosthetic rehabilitation of a young female patient previously affected by bulimia nervosa and presenting erosion of the maxillary teeth. The prosthetic rehabilitation was performed through indirect adhesive restorations of the anterior teeth and direct restorations of the posterior teeth. A clinical follow-up after 4 years showed that the occlusion remained satisfactorily restored. Posterior direct composite resin restorations and anterior indirect adhesive composite restorations proved to be an effective time and money-saving procedure to rehabilitate patients affected by dental erosion. Adhesive rehabilitation provides a functional and good aesthetic result while preserving tooth structure. Key words:Bulimia, dental erosion, composite resin, veneers. PMID:25810832

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

    PubMed

    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.

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

    PubMed Central

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

    2014-01-01

    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. PMID:24698173

  15. Dental Compressed Air Systems.

    DTIC Science & Technology

    1992-03-01

    I AL-TR-IWI-0uuu AD-A249 954 DENTAL COMPRESSED AIMYTM R Curtis D. Weyrmuch, Mejor, USAP, D Samuel P.Dvs iueatclpi SF.O N AEROSPACE MwaEDIN mwr~ComA G...FUNDING NUMBERS Dental Compressed Air Systems PE - 87714F PR - 7350 TA - 22 D. Weyrauch WU - XX Samuel P. Davis George W. Gaines 7. PERFORMING...words) The purpose of this report is to update guidelines on dental compressed air systems (DCA). Much of the information was obtained from a survey

  16. Standing equine dental surgery.

    PubMed

    Menzies, Robert A; Easley, Jack

    2014-04-01

    Dental surgeries refer to procedures that affect the dental tissues or their supporting structures. With the development of specific, efficacious, and conservative treatments, morbidity risks have been lowered and chances of benefiting the health of equids improved. Advances in quality of sedation, analgesia, and locoregional anesthesia allow a majority of dental surgeries to be performed in the standing patient. This update focuses on an orthograde endodontic technique, a minimally invasive buccotomy technique, with the potential to combine it with a transbuccal screw extraction technique, and revisits the AO pinless external fixator for fractures of the body of the mandible.

  17. Feline dental disease.

    PubMed

    Frost, P; Williams, C A

    1986-09-01

    Periodontal disease and chronic gingivitis/stomatitis are the most common feline dental diseases. With routine dental care and increased emphasis on home oral hygiene, these diseases can be controlled. Cats can be seen with a number of other dental disorders, and improved treatment methods such as restorations of early subgingival resorptive lesions, endodontic therapy, and orthodontic therapy can be performed successfully. More study and research are necessary about the gingivitis/stomatitis syndrome and subgingival resorptive lesions so that improved prevention and treatment recommendations can be made.

  18. Economic impact of dental hygienists on solo dental practices.

    PubMed

    Lazar, Vickie F; Guay, Albert H; Beazoglou, Tryfon J

    2012-08-01

    The fact that a significant percentage of dentists employ dental hygienists raises an important question: Are dental practices that utilize a dental hygienist structurally and operationally different from practices that do not? This article explores differences among dental practices that operate with and without dental hygienists. Using data from the American Dental Association's 2003 Survey of Dental Practice, a random sample survey of U.S. dentists, descriptive statistics were used to compare selected characteristics of solo general practitioners with and without dental hygienists. Multivariate regression analysis was used to estimate the effect of dental hygienists on the gross billings and net incomes of solo general practitioners. Differences in practice characteristics--such as hours spent in the practice and hours spent treating patients, wait time for a recall visit, number of operatories, square feet of office space, net income, and gross billings--were found between solo general practitioners who had dental hygienists and those who did not. Solo general practitioners with dental hygienists had higher gross billings. Higher gross billings would be expected, as would higher expenses. However, net incomes of those with dental hygienists were also higher. In contrast, the mean waiting time for a recall visit was higher among dentists who employed dental hygienists. Depending on personal preferences, availability of qualified personnel, etc., dentists who do not employ dental hygienists but have been contemplating that path may want to further research the benefits and opportunities that may be realized.

  19. All-ceramic single-tooth implant reconstructions using modified zirconia abutments: a prospective randomized controlled clinical trial of the effect of pink veneering ceramic on the esthetic outcomes.

    PubMed

    Büchi, Dominik L E; Sailer, Irena; Fehmer, Vincent; Hämmerle, Christoph H F; Thoma, Daniel S

    2014-01-01

    The aim of this study was to test whether veneering of the submucosal part of zirconia abutments using pink veneering ceramic positively influences the color of the peri-implant mucosa. Single-tooth implants were restored with either white zirconia abutments (control group) or pink-veneered zirconia abutments and all-ceramic crowns. Esthetic outcome measurements included a spectrophotometric evaluation of the peri-implant mucosal color. Test and control groups induced a visible discoloration of the peri-implant mucosa after the insertion of the abutments and following cementation of the crowns compared to natural teeth. The calculated color differences were above the clinically visible threshold value and were more favorable for the control group, although not statistically significant. It is concluded that veneering of zirconia abutments with pink veneering ceramic failed to positively influence the esthetic outcome, mostly due to a decrease of the brightness compared with the control group.

  20. Glossary of Dental Terms

    MedlinePlus

    ... of entire communities, and can design and administer large-scale prevention and dental care programs by compiling and analyzing statistics Radiosurgery surgery technique that uses radio waves to produce a pressureless, ...

  1. Interpretation of dental radiographs.

    PubMed

    Woodward, Tony M

    2009-02-01

    Interpretation of dental radiographs is fairly straightforward, with a handful of common patterns making up the majority of pathology. This article covers normal radiographic anatomy, endodontic disease, periodontal disease, neoplastic changes, tooth resorption, caries, and radiographic signs of oral trauma.

  2. Dental Care in Scleroderma

    MedlinePlus

    ... a side effect • Avoid the spiral of depression – depression causes worse oral health and poor oral health worsens depression. Suggestions for your dental appointments: • Tell the dentist ...

  3. American Dental Education Association

    MedlinePlus

    ... ADEA Application Services ADEA AADSAS® ADEA CAAPID® ADEA PASS® ADEA DHCAS® Career Resources DentEd Jobs Placing Ads ... Students & Residents Prospective Students Application Services AADSAS CAAPID PASS DHCAS ADEA AADSAS Applicants Prospective applicants to dental ...

  4. American Dental Hygienists' Association

    MedlinePlus

    ... Working Column Journal of Dental Hygiene Author Guidelines Advertising Subscribe Resources Resources About ADHA About Promo (DO ... Member Benefits Footer Copy Legal Inquiries | Contact Us | Advertising | Media Inquiries | Staff / Board Login ©2012-2017 ADHA. ...

  5. Dental Treatment Considerations

    MedlinePlus

    ... and modifying dental treatment to accommodate altered muscle strength. Appointment Scheduling It is important to realize that ... and take advantage of the typically greater muscle strength during the morning hours. Appointments are best scheduled ...

  6. Dental Caries (Tooth Decay)

    MedlinePlus

    ... form does not collect any actual information. External Web Site Policy This graphic notice ( ) means that you are ... the link. Home Contact Us Viewers and Players Site Map FOIA Web Policies Privacy Policy National Institute of Dental and ...

  7. Diabetes: Dental Tips

    MedlinePlus

    ... form does not collect any actual information. External Web Site Policy This graphic notice ( ) means that you are ... the link. Home Contact Us Viewers and Players Site Map FOIA Web Policies Privacy Policy National Institute of Dental and ...

  8. Portable Dental System

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Portable dental system provides dental care in isolated communities. System includes a patient's chair and a dentist's stool, an X-ray machine and a power unit, all of which fold into compact packages. A large yellow "pumpkin" is a collapsible compressed air tank. Portable system has been used successfully in South America in out of the way communities with this back-packable system, and in American nursing homes. This product is no longer manufactured.

  9. Dental physical examination.

    PubMed

    Baker, G J

    1998-08-01

    The objectives of the equine dental physical examination are to detect and quantify oral and dental disorders, to propose and carry out their treatment, and to implement management programs. The veterinarian should be able to offer a prognosis and to detail any future treatment or management plans that may be required. These objectives should take into account the cost of these procedures, and the veterinarian should be prepared to offer a cost-benefit analysis of the problem and the proposed cures.

  10. Dental considerations in anaesthesia

    PubMed Central

    2016-01-01

    Dental trauma as a result of anaesthesia practice is a relevant issue concerning morbidity and litigation. The investigator aimed to consolidate pertinent information on this issue to aid in the redressal of such an occurrence. A review of this relevant literature alongwith the author’s suggestions towards the management of the various kinds of dental trauma sustained as a result of anaesthesia practice is presented. PMID:27974970

  11. TRICARE Dental Programs

    DTIC Science & Technology

    2011-01-01

    enrollee – $1,500 lifetime maximum for orthodontics – Contractor: Delta Dental of California 2011 MHS Conference TRICARE Retiree Dental Program...Benefits Comprehensive benefits 12-month waiting period for crowns, prosthetics and orthodontics No waiting period if enroll within 120 days of...retiring from active duty or transfer to Retired Reserve status from National Guard or Reserve  Orthodontics for children and adults Accident coverage

  12. Dental arch asymmetry

    PubMed Central

    Al-Zubair, Nabil Muhsen

    2014-01-01

    Objective: This study was conducted to assess the dental arch asymmetry in a Yemeni sample aged (18-25) years. Materials and Methods: The investigation involved clinical examination of 1479 adults; only 253 (129 females, 124 males) out of the total sample were selected to fulfill the criteria for the study sample. Study models were constructed and evaluated to measure mandibular arch dimensions. Three linear distances were utilized on each side on the dental arch: Incisal-canine distance, canine-molar distance and incisal-molar distance, which represent the dental arch segmental measurements. Results: When applying “t-test” at P < 0.05, no significant differences were found between the right and left canine-molar, incisal-canine and incisal-molar distances in both dental arches for both sexes. The greater variation (0.30 mm) was observed between right and left canine-molar distance in the maxillary dental arch in male and the smaller (0.04 mm) in the mandibular dental arch between the right and left canine-molar distance in females. Conclusion: The findings of the present study revealed a symmetrical pattern of dental arches, since the right and left sides showed no statistically significant difference. In general, it can be observed that the measurements related to the central incisors and canines have the widest range of reading and give the impression that the location of central incisor and canines to each other and to other teeth is the strongest factor in determining the dental arch asymmetry. PMID:24966774

  13. Saliva and dental erosion

    PubMed Central

    BUZALAF, Marília Afonso Rabelo; HANNAS, Angélicas Reis; KATO, Melissa Thiemi

    2012-01-01

    Dental erosion is a multifactorial condition. The consideration of chemical, biological and behavioral factors is fundamental for its prevention and therapy. Among the biological factors, saliva is one of the most important parameters in the protection against erosive wear. Objective This review discusses the role of salivary factors on the development of dental erosion. Material and Methods A search was undertaken on MEDLINE website for papers from 1969 to 2010. The keywords used in the research were "saliva", "acquired pellicle", "salivary flow", "salivary buffering capacity" and "dental erosion". Inclusion of studies, data extraction and quality assessment were undertaken independently and in duplicate by two members of the review team. Disagreements were solved by discussion and consensus or by a third party. Results Several characteristics and properties of saliva play an important role in dental erosion. Salivary clearance gradually eliminates the acids through swallowing and saliva presents buffering capacity causing neutralization and buffering of dietary acids. Salivary flow allows dilution of the acids. In addition, saliva is supersaturated with respect to tooth mineral, providing calcium, phosphate and fluoride necessary for remineralization after an erosive challenge. Furthermore, many proteins present in saliva and acquired pellicle play an important role in dental erosion. Conclusions Saliva is the most important biological factor affecting the progression of dental erosion. Knowledge of its components and properties involved in this protective role can drive the development of preventive measures targeting to enhance its known beneficial effects. PMID:23138733

  14. Chemical Compositional Indications of Aqueous Alteration for Whitewater Lake Boxworks, Veneers and Veins at Cape York, Mars

    NASA Astrophysics Data System (ADS)

    Clark, Benton; Gellert, R.; Squyres, S.; Arvidson, R.; Yen, A.; Rice, J.; Athena Science Team

    2013-10-01

    An area of partially-veneered, flat-lying rocks which also includes boxwork and linear veins contains a variety of compositions which are each indicative of minor to major aqueous alteration processes in the Cape York rim of Endeavour Crater. As analyzed by APXS x-ray fluorescence spectroscopy, the sets of unique elemental compositions correspond variously to Al-Si rich clays in boxwork veins, with Fe- and Cl-enriched salt veneers (Esperance samples); swarms of Ca sulfate veins (Ortiz samples); and, as indicated by remote sensing, mafic smectite alteration products in veneers (Chelmsford covering Azilda samples). Multiple offset analyses by APXS reveal clear trends and associations of certain elements, allowing inferences of mineralogies. In contrast to the acidic environment deduced for the genesis of the multiple-sulfate Burns formation sediments and shallow ferric-rich sulfate deposits beneath soils, these alteration products formed at more near-neutral pH, often with major chemical segregations and requiring high water-rock ratios comparable to a wide range of eminently habitable terrestrial environments. Several of these compositions are also rated high with respect to their potential for preservation of organic materials and biomarkers. Within distances of just tens of meters inside this so-called Whitewater Lake unit, this broad diversity exemplifies the tantalizing opportunities as well as challenges for future sample return missions to the red planet, which in this case could also be expanded to include nearby samples of Burns Fm sandstones, hematite concretions, light-toned spherules (Kirkwood), large gypsum veins (Homestake), martian global soils and surface dust.

  15. Redistribution of Lunar Polar Water to Mid-latitudes and Its Role in Forming an OH Veneer

    NASA Technical Reports Server (NTRS)

    Farrell, William M.; Hurley, D. M.; Hodges, R. R.; Killen, R. M.; Halekas, J. S.; Zimmerman, M. I.; Delory, G. T.

    2013-01-01

    We suggest that energization processes like ion sputtering and impact vaporization can eject/release polar water molecules residing within cold trapped regions with sufficient velocity to allow their redistribution to mid-latitudes. We consider the possibility that these polar-ejected molecules can contribution to the water/OH veneer observed as a 3 micrometer IR absorption feature at mid-latitudes by Chandrayaan-1, Cassini, and EPOXI. We find this source cannot fully account for the observed IR feature, but could be a low intensity additional source.

  16. Effect of Different Thicknesses of Pressable Ceramic Veneers on Polymerization of Light-cured and Dual-cured Resin Cements

    PubMed Central

    Cho, Seok-Hwan; Lopez, Arnaldo; Berzins, David W.; Prasad, Soni; Ahn, Kwang Woo

    2015-01-01

    Aim This study evaluated the effects of ceramic veneer thicknesses on the polymerization of two different resin cements. Materials and Methods A total of 80 ceramic veneer discs were fabricated by using a pressable ceramic material (e.max Press; Ivoclar Vivadent) from a Low Translucency (LT) ingot (A1 shade). These discs were divided into light-cured (LC; NX3 Nexus LC; Kerr) and dual-cured (DC; NX3 Nexus DC; Kerr) and each group was further divided into 4 subgroups, based on ceramic disc thickness (0.3 mm, 0.6 mm, 0.9 mm, and 1.2 mm). The values of Vickers microhardness (MH) and degree of conversion (DOC) were obtained for each specimen after a 24-hour storage period. Association between ceramic thickness, resin cement type, and light intensity readings (mW/cm2) with respect to microhardness and degree of conversion was statistically evaluated by using ANOVA. Results For the DOC values, there was no significant difference observed among the LC resin cement subgroups, except in the 1.2 mm subgroup; only the DOC value (14.0 ± 7.4%) of 1.2 mm DC resin cement had significantly difference from that value (28.9 ± 7.5%) of 1.2 mm LC resin cement (P<.05). For the MH values between LC and DC resin cement groups, there was statistically significant difference (P<.05); overall, the MH values of LC resin cement groups demonstrated higher values than DC resin cement groups. On the other hands, among the DC resin cement subgroups, the MH values of 1.2 mm DC subgroup was significantly lower than the 0.3 mm and 0.6 mm subgroups (P<.05). However, among the LC subgroups, there was no statistically significant difference among them (P >.05). Conclusion The degree of conversion and hardness of the resin cement was unaffected with veneering thicknesses between 0.3 and 0.9 mm. However, the DC resin cement group resulted in a significantly lower DOC and MH values for the 1.2 mm subgroup. Clinical Significance While clinically adequate polymerization of LC resin cement can be achieved

  17. Fracture analysis of randomized implant-supported fixed dental prostheses

    PubMed Central

    Esquivel-Upshaw, Josephine F.; Mehler, Alex; Clark, Arthur E.; Neal, Dan; Anusavice, Kenneth J.

    2014-01-01

    Objective Fractures of posterior fixed dental all-ceramic prostheses can be caused by one or more factors including prosthesis design, flaw distribution, direction and magnitude of occlusal loading, and nature of supporting infrastructure (tooth root/implant), and presence of adjacent teeth. This clinical study of implant-supported, all-ceramic fixed dental prostheses, determined the effects of (1) presence of a tooth distal to the most distal retainer; (2) prosthesis loading either along the non-load bearing or load bearing areas; (3) presence of excursive contacts or maximum intercuspation contacts in the prosthesis; and (4) magnitude of bite force on the occurrence of veneer ceramic fracture. Methods 89 implant-supported FDPs were randomized as either a three-unit posterior metal-ceramic (Au-Pd-Ag alloy and InLine POM, Ivoclar, Vivadent) FDP or a ceramic-ceramic (ZirCAD and ZirPress, Ivoclar, Vivadent) FDP. Two implants (Osseospeed, Dentsply) and custom abutments (Atlantis, Dentsply) supported these FDPs, which were cemented with resin cement (RelyX Universal Cement). Baseline photographs were made with markings of teeth from maximum intercuspation (MI) and excursive function. Patients were recalled at 6 months and 1 to 3 years. Fractures were observed, their locations recorded, and images compared with baseline photographs of occlusal contacts. Conclusion No significant relationship exists between the occurrence of fracture and: (1) the magnitude of bite force; (2) a tooth distal to the most distal retainer; and (3) contacts in load-bearing or non-load-bearing areas. However, there was a significantly higher likelihood of fracture in areas with MI contacts only. Clinical Significance This clinical study demonstrates that there is a need to evaluate occlusion differently with implant-supported prostheses than with natural tooth supported prostheses because of the absence of a periodontal ligament. Implant supported prostheses should have minimal occlusion and

  18. 42 CFR Appendix G to Part 75 - Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Dental Assistants in Dental Radiography G Appendix G to Part 75 Public Health PUBLIC HEALTH SERVICE...—Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography The following section... individual State licensure processes, all of which include assessment of competence in dental radiography....

  19. 42 CFR Appendix G to Part 75 - Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Dental Assistants in Dental Radiography G Appendix G to Part 75 Public Health PUBLIC HEALTH SERVICE...—Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography The following section... individual State licensure processes, all of which include assessment of competence in dental radiography....

  20. 42 CFR Appendix G to Part 75 - Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Dental Assistants in Dental Radiography G Appendix G to Part 75 Public Health PUBLIC HEALTH SERVICE...—Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography The following section... individual State licensure processes, all of which include assessment of competence in dental radiography....

  1. 42 CFR Appendix G to Part 75 - Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Dental Assistants in Dental Radiography G Appendix G to Part 75 Public Health PUBLIC HEALTH SERVICE...—Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography The following section... individual State licensure processes, all of which include assessment of competence in dental radiography....

  2. Influence of Full Veneer Restoration on Fracture Resistance of Three Different Core Materials: An Invitro Study

    PubMed Central

    Manoharan, P.S; Shekhawat, Kuldeep Singh; Deb, Saikat; Chidambaram, S.; Konchada, Jagadish; Venugopal, Nirupa; Vadivel, Harish

    2015-01-01

    Aims and Objectives One of the factor which affects the strength of the tooth restored with core material is the property of the material. In clinical situation all such restored teeth are protected by crowns. This study evaluated the strength of different core materials on a compromised tooth structure after restoration with a crown. Materials and Methods Seventy extracted intact human premolars were collected and mounted within a mould using auto-polymerizing resin. The teeth were divided in-to four groups - A, B, C and D. Each group contained 20 teeth except group A with 10 teeth. All the teeth were prepared for full veneer cast crown. Except for the teeth in group: A) extensive class-I cavities were prepared in the teeth of all the groups and restored with; B) composite resin, 3M EPSE Filtek P60; C) Silver reinforced glass ionomer, SHOFU Hi Dense XP and; (D) Resin reinforced glass ionomer, GC Gold Label light cure GIC. All the teeth were restored with cast-metal alloy and exposed to 1.2 million cycles of cyclic loading in a chewing simulator. Subsequently, the teeth that survived were loaded till fracture in the universal testing machine. Fracture loads and type of fractures were recorded. Results All the specimens survived cyclic loading. The mean fracture strength of the silver reinforced glass ionomer was greater with and without crown (p<0.001). Statistical analysis for the mean fracture load of each specimen showed significant difference between the groups. Conclusion Under the condition of this study, core materials when restored with artificial crown had a significant increase in fracture resistance. PMID:26501004

  3. An Evaluation of Frangible Materials as Veneers on Vented Structural Member Designs

    SciTech Connect

    Jameson, Kevin Jay

    2015-10-01

    Literature shows there has been extensive research and testing done in the area of wall panels and frangible materials. There is evidence from past research that shows it is possible to vent a structure that has had an accidental internal explosion [1]. The reviewed literature shows that most designs vent the entire wall panel versus a frangible material attached to the wall panel. The frangible material attachment points are important to determine the overall loading of the wall panel structure [2]. The materials used in the reviewed literature were securely attached as well as strong enough to remain intact during the pressure loading to move the entire wall panel. Since the vented wall panel was the weakest part of the overall structure, the other walls of the structure were substantially larger. The structure was usually built from concrete and large amounts of steel with dirt and sand over the top of the structure.The study will be conducted at Sandia National Laboratories located in Albuquerque New Mexico. The skeletal structural design for evaluation is a rectangular frame with a square grid pattern constructed from steel. The skeletal structure has been given to the researcher as a design requirement. The grid pattern will be evaluated strictly on plastic deformation and the loading that is applied from the frangible material. The frangible material tested will either fit into the grid or will be a veneer lightly attached to the structure frame. The frangible material may be required on both sides of the structure to adequately represent the application.

  4. Influence of resin cement shade on the color and translucency of ceramic veneers

    PubMed Central

    HERNANDES, Daiana Kelly Lopes; ARRAIS, Cesar Augusto Galvão; de LIMA, Erick; CESAR, Paulo Francisco; RODRIGUES, José Augusto

    2016-01-01

    ABSTRACT Objective This in vitro study evaluated the effect of two different shades of resin cement (RC- A1 and A3) layer on color change, translucency parameter (TP), and chroma of low (LT) and high (HT) translucent reinforced lithium disilicate ceramic laminates. Material and Methods One dual-cured RC (Variolink II, A1- and A3-shade, Ivoclar Vivadent) was applied to 1-mm thick ceramic discs to create thin RC films (100 µm thick) under the ceramics. The RC was exposed to light from a LED curing unit. Color change (ΔE) of ceramic discs was measured according to CIEL*a*b* system with a standard illuminant D65 in reflectance mode in a spectrophotometer, operating in the light range of 360-740 nm, equipped with an integrating sphere. The color difference between black (B) and white (W) background readings was used for TP analysis, while chroma was calculated by the formula C* ab=(a*2+b*2)½. ΔE of 3.3 was set as the threshold of clinically unacceptable. The results were evaluated by two-way ANOVA followed by Tukey's post hoc test. Results HT ceramics showed higher ΔE and higher TP than LT ceramics. A3-shade RC promoted higher ΔE than A1-shade cement, regardless of the ceramic translucency. No significant difference in TP was noted between ceramic discs with A1- and those with A3-shade cement. Ceramic with underlying RC showed lower TP than discs without RC. HT ceramics showed lower chroma than LT ceramics, regardless of the resin cement shade. The presence of A3-shade RC resulted in higher chroma than the presence of A1-shade RC. Conclusions Darker underlying RC layer promoted more pronounced changes in ceramic translucency, chroma, and shade of high translucent ceramic veneers. These differences may not be clinically differentiable. PMID:27556211

  5. Highly siderophile element and 182W evidence for a partial late veneer in the source of 3.8 Ga rocks from Isua, Greenland

    NASA Astrophysics Data System (ADS)

    Dale, Christopher W.; Kruijer, Thomas S.; Burton, Kevin W.

    2017-01-01

    The higher-than-expected concentrations of highly siderophile elements (HSE) in Earth's mantle most likely indicate that Earth received a small amount of late accreted mass after core formation had ceased, known as the 'late veneer'. Small 182W excesses in the Moon and in some Archaean rocks - such as the source of 3.8 billion-year-old Isua magmatics - also appear consistent with the late veneer hypothesis, with a lower proportion received. However, 182W anomalies can also relate to other processes, including early mantle differentiation. To better assess the origin of these W isotope anomalies - and specifically whether they relate to the late veneer - we have determined the HSE abundances and 182W compositions of a suite of mafic to ultramafic rocks from Isua, from which we estimate HSE abundances in the source mantle and ultimately constrain the 182W composition of the pre-late veneer mantle. Our data suggest that the Isua source mantle had HSE abundances at around 50-65% of the present-day mantle, consistent with partial, but not complete, isolation from the late veneer. These data also indicate that at least part of the late veneer had been added and mixed into the mantle at the time the Isua source formed, prior to 3.8 Ga. For the same Isua samples we obtained a 13 ± 4 ppm182W excess, compared to the modern terrestrial mantle, in excellent agreement with previous data. Using combined 182W and HSE data we show that the Moon, Isua, and the present-day bulk silicate Earth (BSE) produce a well-defined co-variation between 182W composition and the mass fraction of late-accreted mass, as inferred from HSE abundances. This co-variation is consistent with the calculated effects of various late accretion compositions on the HSE and 182W signatures of Earth's mantle. The empirical relationship, therefore, implies that the Moon, Isua source and BSE received increasing proportions of late-accreted mass, supporting the idea of disproportional late accretion to the Earth

  6. Zirconium dioxide based dental restorations. Studies on clinical performance and fracture behaviour.

    PubMed

    Larsson, Christel

    2011-01-01

    (group 1) and a fully-sintered Y-TZP material (group 2). Eighteen patients were randomly divided between the two groups. At the one-year follow-up, all restorations were in function and no complete fractures were noted. However, fractures of the veneering material were noted. There was a significant difference between the two materials: 54% of the restorations in group 2 showed veneer fractures compared to 8% of the restorations in group 1. Paper IV is a five-year follow-up of the same patient groups. All restorations were still in function without complete fractures, but an increase in veneer fractures was noted: 69% of the restorations in group 2 showed veneer fractures compared to 17% in group 1. In paper II the fracture strength was evaluated for 4-unit Y-TZP fixed dental prosthesis frameworks with different connector dimensions: 2.0, 2.5, 3.0, 3.5 and 4.0 mm. The results showed a significant increase in load at fracture for each increase in connector diameter and recommendations for clinically relevant connector dimensions were suggested. In paper III implant-supported Y-TZP fixed full-arch mandibular dentures were evaluated. At the three-year follow-up all restorations were in function and no complete fractures were noted. However, fractures of the veneering material were noted in nine of the ten patients, affecting 34% of the units. In paper V the fracture strength of crowns with different types of Y-TZP core materials and different core design and different veneering materials was evaluated. The crowns were cemented onto tooth-like abutments, except for one group cemented onto implant-like titanium abutments. The results showed significantly higher loads at fracture and less severe veneer fractures for crowns with anatomically shaped cores compared to simple cores of even thickness. Crowns supported by implant-like titanium abutments showed significantly higher loads at fracture than did those supported by tooth-like abutments. The type of core-material and

  7. Influence of dental materials on dental MRI

    PubMed Central

    Tymofiyeva, O; Vaegler, S; Rottner, K; Boldt, J; Hopfgartner, AJ; Proff, PC; Richter, E-J; Jakob, PM

    2013-01-01

    Objectives: To investigate the potential influence of standard dental materials on dental MRI (dMRI) by estimating the magnetic susceptibility with the help of the MRI-based geometric distortion method and to classify the materials from the standpoint of dMRI. Methods: A series of standard dental materials was studied on a 1.5 T MRI system using spin echo and gradient echo pulse sequences and their magnetic susceptibility was estimated using the geometric method. Measurements on samples of dental materials were supported by in vivo examples obtained in dedicated dMRI procedures. Results: The tested materials showed a range of distortion degrees. The following materials were classified as fully compatible materials that can be present even in the tooth of interest: the resin-based sealer AH Plus® (Dentsply, Maillefer, Germany), glass ionomer cement, gutta-percha, zirconium dioxide and composites from one of the tested manufacturers. Interestingly, composites provided by the other manufacturer caused relatively strong distortions and were therefore classified as compatible I, along with amalgam, gold alloy, gold–ceramic crowns, titanium alloy and NiTi orthodontic wires. Materials, the magnetic susceptibility of which differed from that of water by more than 200 ppm, were classified as non-compatible materials that should not be present in the patient’s mouth for any dMRI applications. They included stainless steel orthodontic appliances and CoCr. Conclusions: A classification of the materials that complies with the standard grouping of materials according to their magnetic susceptibility was proposed and adopted for the purposes of dMRI. The proposed classification can serve as a guideline in future dMRI research. PMID:23610088

  8. History of dental hygiene research.

    PubMed

    Bowen, Denise M

    2013-01-01

    Dental hygiene is defined as the science and practice of the recognition, treatment and prevention of oral diseases. The history of dental hygiene research is considered in the context of the development of the discipline and an emerging infrastructure. Research-related events supporting the growth and maturation of the profession are considered from the early years to the most recent. The benefits of preventive oral health services provided by dental hygienists have been supported by research, and the practice of dental hygiene has expanded as a result of research findings since its inception 100 years ago. Dental hygienists' engagement in research, however, did not begin until the 1960s as research associates or administrators, primarily with dental researchers as primary investigators. The Journal of Dental Hygiene (JDH) has provided information for dental hygiene practice since 1927, and has been the primary venue for dissemination of dental hygiene research since 1945. Graduate education in dental hygiene at the master's degree level and the work of early dental hygiene researchers led to the first conference on dental hygiene research in 1982. Over 30 years later, dental hygiene has established a meta-paradigm and defined conceptual models, built an initial infrastructure to support research endeavors and contributed much to the development of dental hygiene as a unique discipline. A doctoral degree in the discipline, continued theory-based research, initiatives to foster collaborations between dental hygiene and other researchers and enhanced capabilities to attract funding to support large scale studies are goals that must be attained through the efforts of future researchers to address the needs for additional development in the discipline of dental hygiene. Dental hygiene research supports the growing discipline and its value to society.

  9. Dental Implantology in U.S. Dental Schools.

    ERIC Educational Resources Information Center

    Bavitz, J. Bruce

    1990-01-01

    The results of a survey of 44 dental schools corroborate the belief that dental implantology is gaining widespread acceptance in U.S. dental schools. Currently, predoctoral students have limited clinical participation. Most programs have taken the position that clinical techniques are best taught within the existing specialties at a graduate…

  10. Bulimia and Anorexia Nervosa in Dental and Dental Hygiene Curricula.

    ERIC Educational Resources Information Center

    Gross, Karen B. W.; And Others

    1990-01-01

    Dentists and dental hygienists are in a unique position to identify an eating disorder patient from observed oral manifestations and to refer the patient for psychological therapy. The inclusion of information on general and oral complications of bulimia and anorexia nervosa in dental and dental hygiene curriculum was examined. (MLW)

  11. Improved communication with the laboratory for the fabrication of labial veneers.

    PubMed

    Schwartzman, Aaron; Zweig, Alan E

    2015-04-01

    Advances in dental materials and adhesive technologies have changed the way we practice dentistry. Consequently, restorative dentistry has seen the adoption and almost exponential increase in usage of materials like zirconia and lithium disilicate. Unlike the incidence of ceramic failure in the past, these newer materials are paving the road to better looking dentistry. This paper focuses on lithium disilicate and predominantly glassy ceramics, as well as improving communication with the laboratory.

  12. Panoramic Dental X-Ray

    MedlinePlus

    ... Physician Resources Professions Site Index A-Z Panoramic Dental X-ray Panoramic dental x-ray uses a ... Your e-mail address: Personal message (optional): Bees: Wax: Notice: RadiologyInfo respects your privacy. Information entered here ...

  13. Effect of intermediate ceramics and firing temperature on bond strength between tetragonal zirconia polycrystal and veneering ceramics.

    PubMed

    Matsumoto, Naoya; Yoshinari, Masao; Takemoto, Shinji; Hattori, Masayuki; Kawada, Eiji; Oda, Yutaka

    2013-01-01

    The purpose of the present study was to investigate the influence of the intermediate ceramics and firing temperature on bond strength between tetragonal zirconia polycrystal (TZP) and its intermediate ceramics. Two types of intermediate ceramics, defined as a ceramics placed between the TZP and its veneering ceramics, were used; one including high-strength lithium-disilicate (EP) or feldspathic liner porcelain (SB). The firing temperature of the intermediate ceramics was set at 930°C, 945°C or 960°C. Shear bond strength showed values of 35.8 MPa in SB and 54.9 MPa in EP at a firing temperature of 960°C. Electron probe microanalysis revealed that components of the intermediate ceramics remained on the TZP surface after debonding, indicating that fractures occurred in the intermediate ceramics near the TZP. These results indicate that the bond strength between and a TZP framework and its veneering ceramics could be improved by using a high-strength intermediate ceramics and a comparatively high firing temperature.

  14. The Primary Dental Care Workforce.

    ERIC Educational Resources Information Center

    Neenan, M. Elaine; And Others

    1993-01-01

    A study describes the characteristics of the current primary dental care workforce (dentists, hygienists, assistants), its distribution, and its delivery system in private and public sectors. Graduate dental school enrollments, trends in patient visits, employment patterns, state dental activities, and workforce issues related to health care…

  15. Dental ethics and emotional intelligence.

    PubMed

    Rosenblum, Alvin B; Wolf, Steve

    2014-01-01

    Dental ethics is often taught, viewed, and conducted as an intell enterprise, uninformed by other noncognitive factors. Emotional intelligence (EQ) is defined distinguished from the cognitive intelligence measured by Intelligence Quotient (IQ). This essay recommends more inclusion of emotional, noncognitive input to the ethical decision process in dental education and dental practice.

  16. Dental therapists: a global perspective.

    PubMed

    Nash, David A; Friedman, Jay W; Kardos, Thomas B; Kardos, Rosemary L; Schwarz, Eli; Satur, Julie; Berg, Darren G; Nasruddin, Jaafar; Mumghamba, Elifuraha G; Davenport, Elizabeth S; Nagel, Ron

    2008-04-01

    In 1921, New Zealand began training school dental nurses, subsequently deploying them throughout the country in school-based clinics providing basic dental care for children. The concept of training dental nurses, later to be designated dental therapists, was adopted by other countries as a means of improving access to care, particularly for children. This paper profiles six countries that utilise dental therapists, with a description of the training that therapists receive in these countries, and the context in which they practice. Based on available demographic information, it also updates the number of dental therapists practising globally, as well as the countries in which they practice. In several countries, dental therapy is now being integrated with dental hygiene in training and practice to create a new type of professional complementary to a dentist. Increasingly, dental therapists are permitted to treat adults as well as children. The paper also describes the status of a current initiative to introduce dental therapy to the United States. It concludes by suggesting that dental therapists can become valued members of the dental team throughout the world, helping to improve access to care and reducing existing disparities in oral health.

  17. Dental Assistant Specialist. (AFSC 98150).

    ERIC Educational Resources Information Center

    Eling, David R.

    This four-volume student text is designed for use by Air Force personnel enrolled in a self-study extension course for dental assistant specialists. Covered in the individual volumes are an introduction to dental services (the mission and organization of medical/dental service, career ladder progressions, medical readiness/wartime training, and…

  18. Dental Laboratory Technology Program Standards.

    ERIC Educational Resources Information Center

    Georgia Univ., Athens. Dept. of Vocational Education.

    This guide contains 45 program standards for the dental laboratory technology program conducted in technical institutes in Georgia. The dental laboratory technology program, either diploma or associate degree, is designed to ensure that students gain basic competence in the job skills needed for an entry-level employee in dental laboratory…

  19. The Future Dental Education Process.

    ERIC Educational Resources Information Center

    Hjorting-Hansen, Erik

    1996-01-01

    Directions for dental education are examined, with reference made to a number of recent background papers and an Institute of Medicine report on dental education in the United States. Greater integration with other health sciences, development of dental faculty teaching skills, and greater use of apprenticeships and continuing education are…

  20. Dental amalgam: An update

    PubMed Central

    Bharti, Ramesh; Wadhwani, Kulvinder Kaur; Tikku, Aseem Prakash; Chandra, Anil

    2010-01-01

    Dental amalgam has served as an excellent and versatile restorative material for many years, despite periods of controversy. The authors review its history, summarize the evidence with regard to its performance and offer predictions for the future of this material. The PubMed database was used initially; the reference list for dental amalgam featured 8641 articles and 13 publications dealing with recent advances in dental amalgam. A forward search was undertaken on selected articles and using some author names. For the present, amalgam should remain the material of choice for economic direct restoration of posterior teeth. When esthetic concerns are paramount, tooth-colored materials, placed meticulously, can provide an acceptable alternative. All alternative restorative materials and procedures, however, have certain limitations. PMID:21217947

  1. Dental pulp stem cells

    PubMed Central

    Ashri, Nahid Y.; Ajlan, Sumaiah A.; Aldahmash, Abdullah M.

    2015-01-01

    Inflammatory periodontal disease is a major cause of loss of tooth-supporting structures. Novel approaches for regeneration of periodontal apparatus is an area of intensive research. Periodontal tissue engineering implies the use of appropriate regenerative cells, delivered through a suitable scaffold, and guided through signaling molecules. Dental pulp stem cells have been used in an increasing number of studies in dental tissue engineering. Those cells show mesenchymal (stromal) stem cell-like properties including self-renewal and multilineage differentiation potentials, aside from their relative accessibility and pleasant handling properties. The purpose of this article is to review the biological principles of periodontal tissue engineering, along with the challenges facing the development of a consistent and clinically relevant tissue regeneration platform. This article includes an updated review on dental pulp stem cells and their applications in periodontal regeneration, in combination with different scaffolds and growth factors. PMID:26620980

  2. Fracture stability of anterior zirconia crowns with different core designs and veneered using the layering or the press-over technique.

    PubMed

    Eisenburger, Michael; Mache, Tobias; Borchers, Lothar; Stiesch, Meike

    2011-06-01

    In the current in vitro study, the fracture stability of anterior crowns with zirconia cores of different designs was investigated after applying different veneering techniques. Four groups of zirconia cores (n = 10 in each group) were produced using a computer-aided design/computer-aided manufacturing (CAD/CAM) process. Cores with a standard cervical design were veneered using the layering technique (CCL) or the press-over technique (CCP). Further cores were designed with a porcelain shoulder, where the cervical margin of the zirconia core was reduced by 1 mm. These cores were also veneered using the layering technique (PSL) or the press-over technique (PSP). All crowns were cemented onto metal teeth and loaded until fracture in a universal testing machine. Chipping or fracture of the core was found to occur for CCL at 919±265 N (mean ±SD), for CCP at 798±226 N, for PSL at 739±184 N, and for PSP at 734±209 N. anova did not show significant differences between the four groups. For CCL and CCP, fracture lines ran in a mesio-distal orientation. For PSL and PSP, fracture lines ran into the porcelain shoulder. In summary, the use of a porcelain shoulder can be recommended with zirconia crowns in combination with either the layering or the press-over veneering technique.

  3. In vitro evaluation of the fracture resistance and microleakage of porcelain laminate veneers bonded to teeth with composite fillings after cyclic loading

    PubMed Central

    Sadighpour, Leyla; Fallahi Sichani, Babak; Kharazi Fard, Mohamd Javad

    2014-01-01

    PURPOSE There is insufficient data regarding the durability of porcelain laminate veneers bonded to existing composite fillings. The aim of the present study was to evaluate the fracture resistance and microleakage of porcelain laminate veneers bonded to teeth with existing composite fillings. MATERIALS AND METHODS Thirty maxillary central incisors were divided into three groups (for each group, n=10): intact teeth (NP), teeth with class III composite fillings (C3) and teeth with class IV cavities (C4). Porcelain laminate veneers were made using IPS-Empress ceramic and bonded with Panavia F2 resin cement. The microleakage of all of the specimens was tested before and after cyclic loading (1 × 106 cycles, 1.2 Hz). The fracture resistance values (N) were measured using a universal testing machine, and the mode of failure was also examined. The statistical analyses were performed using one-way ANOVA and Tukey post hoc tests (α=.05). RESULTS There was a significant difference in the mean microleakage of group C4 compared with group NT (P=.013). There was no significant difference in the fracture loads among the groups. CONCLUSION The microleakage and failure loads of porcelain laminate veneers bonded to intact teeth and teeth with standard class III composite fillings were not significantly different. PMID:25177471

  4. Widespread evidence for a late veneer on the terrestrial planets and planetisimals

    NASA Astrophysics Data System (ADS)

    Dale, C. W.; Burton, K.; Pearson, G.; Greenwood, R. C.

    2010-12-01

    Growth of the Earth from smaller planetisimals resulted in substantial partitioning of the iron-loving (siderophile) into the metallic core. However, some of the most highly siderophile elements in Earth’s silicate mantle are present in much greater concentrations than expected, even for high-pressure equilibration in a deep ‘magma ocean’ [1], and in broadly chondritic proportions. Consequently, it is often assumed that the highly siderophile elements require the late addition of extraterrestrial material (the so called ‘late veneer’) to the mantle after core formation was complete. Core formation on smaller asteroidal bodies cannot have been affected by high-pressure equilibration, and Hf-W chronology suggests that core formation was rapid [2] and, during global scale melting, was likely highly efficient [3]. This study presents new HSE abundance and 187Os/188Os isotope data for basaltic meteorites, the HEDs (Howardites, Eucrites and Diogenites thought to sample the asteroid 4 Vesta), anomalous Eucrites and Angrites (considered to be from distinct parent bodies) and SNCs (thought to be from Mars). The results show that these igneous meteorites all formed from mantle sources that possessed broadly chondritic (i.e. primitive solar system) inter-element ratios and Os isotope compositions, inconsistent with equilibrium partitioning of the PGE. Furthermore, there is a simple relationship where predicted mantle HSE concentrations are linked to the size of the parent body, and so Vesta (like the Moon [4]) has much lower HSE concentrations than Earth or Mars. These data can be most readily explained by the late addition of a chondritic meteorite flux to the silicate mantles of all these bodies, after core formation was complete, and suggests that the addition of a late veneer is a general feature of planetary accretion in the inner solar system, rather than being a unique temporal event that only affected the Earth. [1] Wood, B.J., Walter, M.J. & Wade, J. (2006

  5. Performance of Dental Ceramics

    PubMed Central

    Rekow, E.D.; Silva, N.R.F.A.; Coelho, P.G.; Zhang, Y.; Guess, P.; Thompson, V.P.

    2011-01-01

    The clinical success of modern dental ceramics depends on an array of factors, ranging from initial physical properties of the material itself, to the fabrication and clinical procedures that inevitably damage these brittle materials, and the oral environment. Understanding the influence of these factors on clinical performance has engaged the dental, ceramics, and engineering communities alike. The objective of this review is to first summarize clinical, experimental, and analytic results reported in the recent literature. Additionally, it seeks to address how this new information adds insight into predictive test procedures and reveals challenges for future improvements. PMID:21224408

  6. Epilepsy in dental practice.

    PubMed

    Fitzpatrick, J J; McArdle, N S; Wilson, M H; Stassen, L F A

    2008-01-01

    Epilepsy is a neurological condition characterised by seizure activity. It has an approximate incidence of 1%. General dental practitioners will encounter these patients in practice. This article discusses the types of epilepsy, the medical management and considerations in dental management of epileptic patients. General recommendations are made, based on current evidence, with respect to prescribing of medications. The management of an epileptic seizure is discussed. Status epilepticus is a rare but serious complication of epileptic seizures. An easy-to-follow algorithm is provided to assist the practitioner in managing seizures.

  7. Core of Theia as source of much of the Earth's late veneer and implications of a relatively benign Late Heavy Bombardment

    NASA Astrophysics Data System (ADS)

    Sleep, N. H.

    2015-12-01

    The mantle of the Earth contains Pt-group elements along with S, Se, and Te is roughly chondritic relative ratios, but with absolute concentrations of less than 1% chondrite. This property is expected for a mechanical mixture into the mantle which was previous depleted in Pt-group elemnts, but not for equilibrium partition between silicate and molten iron. The well-known late-veneer hypothesis states that this material arrived after the moon-forming impact within bodies with a total mass of 0.3-0.7% of the Earth's mantle. The ratio of the mass of the lunar veneer component to the Moon's mass is much less. For this situation to occur, most of the mass of the impactors was concentrated in the few largest bodies that crashed into the large Earth, rather than the small Moon. Several of these bodies were large enough to sterile the Earth by boiling the oceans. Alternatively, much of the terrestrial veneer came from the core of the moon-forming impactor Theia, rather than from later bodies. Recent lunar studies show that the Moon likely contains "excess" iron spewed from Theia's core. The mass of the lunar core is ~1.6×1021 kg. There is also an excess FeO component in the lunar mantle of 1.3-3.5x1021 kg as Fe. The total excess (core + mantle) lunar Fe is 3-5x1021 kg or ~2% of Theia's core. This mass is comparable to the excess Fe of 2.3-10x1021 kg in the Earth's mantle inferred from the Pt-group veneer and chondritic Fe/Pt. Most likely Fe metal from Theia's core entered the Moon-forming disk. Part of the Fe was oxidized by H2O and Fe2O3 in the disk, leaving the lunar mantle near the Fe-FeO buffer. The remaining iron metal condensed, gathered lunar Pt-group elements from the disk, and became the lunar core. The lunar crust and mantle are hence strongly depleted in Pt-group elements, implying a thin late veneer. In contrast, the Earth's mantle contained excess oxidants. The admixed Fe from Theia's core was nearly quantitatively oxidized. H2O and Fe2O3 components remained

  8. Review of Spaceflight Dental Emergencies

    NASA Technical Reports Server (NTRS)

    Menon, Anil

    2012-01-01

    All exploration class missions--extending beyond earth's orbit--differ from existing orbital missions by being of longer duration and often not having a means of evacuation. If an exploration mission extends beyond a year, then there will be a greater lapse since the crewmembers last terrestrial dental exams, which routinely occur each year. This increased time since professional dental care could increase the chance of a dental emergency such as intractable pain, dental decay requiring a temporary filling, crown replacement, exposed pulp, abscess, tooth avulsion, or toothache. Additionally, any dental emergency will have to be treated in-flight with available resources and personnel who may not have extensive training in dental care. Thus, dental emergencies are an important risk to assess in preparation for exploration missions.

  9. Drugs that promote dental caries.

    PubMed

    2015-02-01

    Dental caries result from erosion of tooth enamel or cementum by acidic substances produced by bacteria found in dental plaque. Caries can lead to pulp necrosis and tooth loss. Risk factors include certain dietary habits, poor oral hygiene, and dry mouth. Diabetes and Sjogren's syndrome can also promote dental caries. Psychotropic substances such as cocaine, methamphetamine, heroin and cannabis can promote dental caries. Many medicinal drugs facilitate the formation of dental caries, through various mechanisms; they include formulations with a high sugar content; drugs that cause dry mouth (especially antimuscarinics); drugs that lower the buccal pH (inhaled powders, etc.); and drugs that cause demineralisation (tetracyclines, etc.). In practice, patients (and parents) should be informed that some drugs can increase the risk of dental caries. They should be encouraged to adapt and reinforce dental hygiene, and advised to visit a dentist regularly.

  10. Dental Sealants Prevent Cavities

    MedlinePlus

    ... Obesity Prescription Drug Overdoses Teen Pregnancy Tobacco Other Digital Media Tools About Vital Signs Get Email Updates To receive email updates about this page, enter your email address: Enter Email Address What's this? Submit What's ... Kit Read the MMWR Science Clips Dental ...

  11. Smoking and dental implants

    PubMed Central

    Kasat, V.; Ladda, R.

    2012-01-01

    Smoking is a prevalent behaviour in the population. The aim of this review is to bring to light the effects of smoking on dental implants. These facts will assist dental professionals when implants are planned in tobacco users. A search of “PubMed” was made with the key words “dental implant,” “nicotine,” “smoking,” “tobacco,” and “osseointegration.” Also, publications on tobacco control by the Government of India were considered. For review, only those articles published from 1988 onward in English language were selected. Smoking has its influence on general as well as oral health of an individual. Tobacco negatively affects the outcome of almost all therapeutic procedures performed in the oral cavity. The failure rate of implant osseointegration is considerably higher among smokers, and maintenance of oral hygiene around the implants and the risk of peri-implantitis are adversely affected by smoking. To increase implant survival in smokers, various protocols have been recommended. Although osseointegrated dental implants have become the state of the art for tooth replacement, they are not without limitations or complications. In this litigious era, it is extremely important that the practitioner clearly understands and is able and willing to convey the spectrum of possible complications and their frequency to the patients. PMID:24478965

  12. FATIGUE OF DENTAL CERAMICS

    PubMed Central

    Zhang, Yu; Sailer, Irena; Lawn, Brian R

    2013-01-01

    Objectives 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. Data/sources The nature of various fatigue modes is elucidated using fracture test data on ceramic layer specimens from the dental and biomechanics literature. Conclusions 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. Clinical significance Strategies for prolonging the clinical lifetimes of ceramic restorations are proposed based on a crack-containment philosophy. PMID:24135295

  13. Advances in dental materials.

    PubMed

    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.

  14. American Dental Association

    MedlinePlus

    ... Dental Medicine: Balancing Our Compassion for Patients with Social Responsibility April 13, 2-3 p.m. (CT) ASDA DAT Week April 17-21 FACEBOOK LIVE: The Top Three Questions Patients Ask about Fluoride April 18, ... Social ADA Twitter ADA News Twitter ADA Facebook GKAS ...

  15. Clinical canine dental radiography.

    PubMed

    Bannon, Kristin M

    2013-05-01

    The purpose of this article is to provide small animal veterinarians in private practice a guideline for interpretation of the most common findings in canine intraoral radiology. Normal oral and dental anatomy is presented. A brief review of variations of normal, common periodontal and endodontic pathology findings and developmental anomalies is provided.

  16. Dental amalgam and mercury

    SciTech Connect

    Mackert, J.R. Jr. )

    1991-08-01

    This paper looks at the issues of the current amalgam controversy: the daily dose of mercury from amalgam, hypersensitivity to mercury, claims of adverse effects from amalgam mercury and alleged overnight 'cures.' In addition, the toxicity and allergenicity of the proposed alternative materials are examined with the same kind of scrutiny applied by the anti-amalgam group to dental amalgam. 100 references.

  17. Dental Optical Coherence Tomography

    PubMed Central

    Hsieh, Yao-Sheng; Ho, Yi-Ching; Lee, Shyh-Yuan; Chuang, Ching-Cheng; Tsai, Jui-che; Lin, Kun-Feng; Sun, Chia-Wei

    2013-01-01

    This review paper describes the applications of dental optical coherence tomography (OCT) in oral tissue images, caries, periodontal disease and oral cancer. The background of OCT, including basic theory, system setup, light sources, spatial resolution and system limitations, is provided. The comparisons between OCT and other clinical oral diagnostic methods are also discussed. PMID:23857261

  18. Financing Dental Education.

    ERIC Educational Resources Information Center

    Douglass, Chester; Fein, Rashi

    1995-01-01

    Analysis of the current status of and recent trends in dental school finances provides an overall financial description, documents trends in revenue and expenses, discusses student debt and its consequences, and presents alternatives for increasing revenues and decreasing expenses. The paper provides background for an Institute of Medicine study…

  19. High elastic modulus nanopowder reinforced resin composites for dental applications

    NASA Astrophysics Data System (ADS)

    Wang, Yijun

    2007-12-01

    Dental restorations account for more than $3 billion dollars a year on the market. Among them, all-ceramic dental crowns draw more and more attention and their popularity has risen because of their superior aesthetics and biocompatibility. However, their relatively high failure rate and labor-intensive fabrication procedure still limit their application. In this thesis, a new family of high elastic modulus nanopowder reinforced resin composites and their mechanical properties are studied. Materials with higher elastic modulus, such as alumina and diamond, are used to replace the routine filler material, silica, in dental resin composites to achieve the desired properties. This class of composites is developed to serve (1) as a high stiffness support to all-ceramic crowns and (2) as a means of joining independently fabricated crown core and veneer layers. Most of the work focuses on nano-sized Al2O3 (average particle size 47 nm) reinforcement in a polymeric matrix with 50:50 Bisphenol A glycidyl methacrylate (Bis-GMA): triethylene glycol dimethacrylate (TEGDMA) monomers. Surfactants, silanizing agents and primers are examined to obtain higher filler levels and enhance the bonding between filler and matrix. Silane agents work best. The elastic modulus of a 57.5 vol% alumina/resin composite is 31.5 GPa compared to current commercial resin composites with elastic modulus <15 GPa. Chemical additives can also effectively raise the hardness to as much as 1.34 GPa. Besides>alumina, diamond/resin composites are studied. An elastic modulus of about 45 GPa is obtained for a 57 vol% diamond/resin composite. Our results indicate that with a generally monodispersed nano-sized high modulus filler, relatively high elastic modulus resin-based composite cements are possible. Time-dependent behavior of our resin composites is also investigated. This is valuable for understanding the behavior of our material and possible fatigue testing in the future. Our results indicate that with

  20. 42 CFR Appendix G to Part 75 - Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Standards for Licensing Dental Hygienists and...—Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography The following section... personnel who perform radiologic procedures. Currently, Dental Hygienists are credentialed...

  1. Dental anxiety and salivary cortisol levels before urgent dental care.

    PubMed

    Kanegane, Kazue; Penha, Sibele S; Munhoz, Carolina D; Rocha, Rodney G

    2009-12-01

    Dental anxiety is still prevalent, despite advances in treatment, and affects the utilization of health care services. The purpose of this cross-sectional study was to determine if patients with different degrees of dental anxiety and pain undergoing emergency dental care have different stress reactions as measured by salivary cortisol. Seventy three patients completed the modified dental anxiety scale (MDAS), and described any previous dental traumatic experience. Their socio-demographic characteristics were also recorded. They also rated pain intensity on a 100 mm visual analogue scale (VAS). A saliva sample was collected before the procedure, and analyzed by enzyme immunoassay. Thirty patients were dentally anxious and forty one complained of pain. In this sample, dental anxiety was not related to gender, age, educational level and family income; however, a previous traumatic event was related to dental anxiety. There was no association between salivary cortisol concentrations and gender or dental anxiety. Patients with pain showed higher cortisol levels. When gathering patient information, the dentist should note patients' negative dental experiences in order to provide more effective, less traumatic treatment.

  2. 21 CFR 872.3240 - Dental bur.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... materials intended for use in the fabrication of dental devices. (b) Classification. Class I (general... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Dental bur. 872.3240 Section 872.3240 Food and... DENTAL DEVICES Prosthetic Devices § 872.3240 Dental bur. (a) Identification. A dental bur is a...

  3. Dental Health - Multiple Languages: MedlinePlus

    MedlinePlus

    ... 繁體中文 (Chinese - Traditional) PDF California Dental Association Dental Tourism English 牙科旅行 - 繁體中文 (Chinese - Traditional) PDF California Dental ... NEEG MOB - Hmoob (Hmong) California Dental Association Dental Tourism English Kev Kho Hniav Txawv Teb Chaws - Hmoob ( ...

  4. Allied Dental Education: Past, Present, and Future.

    ERIC Educational Resources Information Center

    DeVore, Linda Rubinstein

    1993-01-01

    A discussion of the status of the three allied dental disciplines (dental assisting, dental technology, and dental hygiene) gives a historical overview on allied dental programs, assesses their current status and enrollment trends, identifies critical issues affecting educational programs, and outlines a framework for innovation in recruitment and…

  5. Prevalence of Dental Fear and Anxiety amongst Patients in Selected Dental Clinics in Ghana

    ERIC Educational Resources Information Center

    Ofori, Marian A.; Adu-Ababio, F.; Nyako, E. A.; Ndanu, Tom A.

    2009-01-01

    Objective: To find out the prevalence of dental anxiety and fear amongst patients in various selected dental clinics in Accra, Ghana. Study design: Dental patients (n = 279) who had either been exposed to dental treatments or had no prior dental exposure, attending four selected dental clinics in Accra were randomly sampled. They were interviewed…

  6. [Dental education in Germany: new concepts for the dental curriculum].

    PubMed

    Hugger, A; Hugger, S; Kordass, B

    2011-09-01

    In Germany, the dental curriculum is still based on dental licensing regulations ("Approbations-/Prüfungsordnung für Zahnärzte") from 1955. Essential changes of the dental licensing regulations have not been made for over 50 years-unlike the medical licensing regulations in Germany. Teaching and learning concepts have, nevertheless, changed considerably in medical and dental education over time. The present study delivers an analysis about reform initiatives in dental education in Germany and introduces examples of innovative projects. To be able to establish long-term and broad reforms in dental education, new licensing regulations for dentists are required. This should create a contemporary framework for education, which assigns resources and enables occupational profile development at specific locations. Thereby, compatibility with the medical curriculum has to be guaranteed just as required adaptations of admission and curricular capacity regulations for dentistry.

  7. Secondary overprinting of S-Se-Te signatures in the Earth's mantle: Implications for the Late Veneer

    NASA Astrophysics Data System (ADS)

    Koenig, S.; Luguet, A.; Lorand, J.; Pearson, D.

    2013-12-01

    Sulphur, Selenium and Tellurium are both chalcophile and highly siderophile elements (HSE) with near-chondritic ratios and absolute abundances in the terrestrial mantle that exceed those predicted by core-mantle differentiation[1]. These 'excess' HSE abundances have been attributed to addition of ca. 0.5% of chondrite-like material that hit the Earth in its accretionary stage between 4 to 3.8 billion years ago after core-mantle differentiation (Late Veneer[2]). Therefore, like other HSE, S, Se and Te are considered potential tracers for the composition of the Late Veneer, provided that their bulk silicate Earth abundances are properly constrained. In contrast to ca. 250 ppm S, Se and Te are ultra-trace elements in the terrestrial mantle. Like all HSE, they are furthermore controlled by base metal sulphides (BMS) and micrometric platinum group minerals (PGMs)[3]. This strong control exerted by the host mineralogy and petrology on the S-Se-Te systematics at both the micro-scale and the whole-rock scale makes detailed mineralogical and petrological studies of BMS and PGM a pre-requisite to fully understand and accurately interpret the whole-rock signatures. Here we combine in-situ sulphide data and detailed mineralogical observations with whole-rock S-Se-Te-HSE signatures of both lherzolites and harburgites from different geodynamic settings. We demonstrate that the near-chondritic Se and Te signature of 'fertile' mantle rocks (Se/Te ≈9×5) is not a primitive signature of the Earth's mantle, but rather reflects strong enrichment in metasomatic HSE host phases, which erased previous pristine signatures. Consequently, current attempts to identify a potential Late Veneer composition are seriously flawed because, neither refertilisation/metasomatism nor true melt depletion (e.g. harzburgitic residues) have been taken into account for the Primitive Upper Mantle composition estimate[4]. Our combined whole rock and in-situ sulphide data indicate a refertilisation trend

  8. In Vitro Evaluation of Veneering Composites and Fibers on the Color of Fiber-Reinforced Composite Restorations

    PubMed Central

    Hasani Tabatabaei, Masoomeh; Hasani, Zahra; Ahmadi, Elham

    2014-01-01

    Objective: Color match between fiber-reinforced composite (FRC) restorations and teeth is an imperative factor in esthetic dentistry. The purpose of this study is to evaluate the influence of veneering composites and fibers on the color change of FRC restorations. Materials and Methods: Glass and polyethylene fibers were used to reinforce a direct microhybrid composite (Z250, 3M ESPE) and a microfilled composite (Gradia Indirect, GC). There were eight experimental groups (n=5 disks per group). Four groups were used as the controls (non-FRC control) and the others were used as experimental groups. CIELAB parameters (L*, a* and b*) of specimens were evaluated against a white background using a spectrophotometer to assess the color change. The color difference (ΔE*) and color coordinates were (L*, a* and b*) analyzed by two-way ANOVA and Tukey’s test. Results: Both types of composite and fiber influenced the color parameters (ΔL*, Δa*). The incorporation of fibers into the composite in the experimental groups made them darker than the control groups, except in the Gradia Indirect+ glass fibers group. Δb* is affected by types of fibers only in direct fiber reinforced composite. No statistically significant differences were recognized in ΔE* among the groups (p>0.05). Conclusion: The findings of the present study suggest that the tested FRC restorations exhibited no difference in color in comparison with non-FRC restoration. Hence, the types of veneering composites and fibers did not influence the color change (ΔE*) of FRC restorations. PMID:25584060

  9. Dental therapists in general dental practices: an economic evaluation.

    PubMed

    Beazoglou, Tryfon J; Lazar, Vickie F; Guay, Albert H; Heffley, Dennis R; Bailit, Howard L

    2012-08-01

    Dental access disparities are well documented and have been recognized as a national problem. Their major cause is the lack of reasonable Medicaid reimbursement rates for the underserved. Specifically, Medicaid reimbursement rates for children average 40 percent below market rates. In addition, most state Medicaid programs do not cover adults. To address these issues, advocates of better oral health for the underserved are considering support for a new allied provider--a dental therapist--capable of providing services at a lower cost per service and in low-income and rural areas. Using a standard economic analysis, this study estimated the potential cost, price, utilization, and dentist's income effects of dental therapists employed in general dental practices. The analysis is based on national general dental practice data and the broadest scope of responsibility for dental therapists that their advocates have advanced, including the ability to provide restorations and extractions to adults and children, training for three years, and minimum supervision. Assuming dental therapists provide restorative, extraction, and pulpal services to patients of all ages and dental hygienists continue to deliver all hygiene services, the mean reduction in a general practice costs ranges between 1.57 and 2.36 percent. For dental therapists treating children only, the range is 0.31 to 0.47 percent. The effects on price and utilization are even smaller. In addition, the effects on most dentists' gross income, hours of work, and net income are negative. The estimated economic impact of dental therapists in the United States on private dental practice is very limited; therefore, the demand for dental therapists by private practices also would probably be very limited.

  10. Dental-service Dental Radiation Safety and Protection: Program guide

    SciTech Connect

    Not Available

    1991-08-27

    The primary purpose of the program guide for Dental Radiation Safety and Protection is to assist VA dental personnel in developing radiologic procedures that ensure maximum safety for their patients and themselves. In order to do this, the authors have included a summary of the biological hazards associated with exposure to x-radiation, provided information on patient exposure levels associated with dental X-ray units, and explained the methods for reducing patient and staff exposure to X-rays.

  11. An in vitro comparison of four surface preparation techniques for veneering a compomer to stainless steel.

    PubMed

    Salama, F S; el-Mallakh, B F

    1997-01-01

    Compomers are a new class of materials reportedly having the anticariogenicity and the bonding ability to metals similar to glass ionomers while maintaining the high esthetic qualities of composite resins. The purpose of this study was to determine and evaluate the shear bond strength and fracture pattern of a compomer (Dyract) to stainless steel crowns (SSCs) using different mechanical and chemical retention procedures for possible future development of a chair-side technique of producing esthetic SSCs. Thirty-two Unitek SSCs, divided into four groups, were mounted in autopolymerizing acrylic resin so that the resulting specimen has the crown's flat lingual surface projecting above and parallel to the top surface of the acrylic resin block. Dyract was placed in transparent nylon cylinders (3 x 3 mm) and bonded to SSC's surfaces directly (group 1) or following sandblasting of the SSCs (group 2). In group 3, Dyract was bonded to stainless steel lingual cleats that were previously spot-welded to the SSCs. In group 4, Dyract was bonded to sandblasted SSC's surfaces using Scotchbond Multi-Purpose Plus dental adhesive. Specimens were placed in deionized water for 1 hr at 37 degrees C. Shear bond strength was measured using a universal testing machine. The mean (SD) shear bond strengths in MPa for groups 1-4 respectively were as follows: 2.998 (1.381), 9.518 (2.464), 13.909 (1.653), and 9.372 (3.723). One-way ANOVA and Tukey's multiple range tests revealed a statistically significant difference between the groups (P < 0.00001). While no significant difference was found between groups 2 and 4 in which Dyract-PSA prime/adhesive and Scotchbond Multi-Purpose Plus dental adhesive were used, group 3 had significantly higher shear bond strength than other groups. Stereoscopic and SEM examinations revealed adhesive and mixed bond failures. It is concluded that the bond strength of Dyract to SSCs could be enhanced significantly by applying simple mechanical means of retention

  12. A Partial Late Veneer for the Source of 3.8 Ga Isua Rocks: Evidence from Highly Siderophile Elements and 182W

    NASA Astrophysics Data System (ADS)

    Dale, C.; Kruijer, T.; Burton, K. W.; Kleine, T.; Moorbath, S.

    2015-12-01

    Highly siderophile elements (HSE) were strongly sequestered into metallic planetary cores, leaving silicate mantles almost devoid of HSE. Late accretion partially replenished HSE in planetary mantles soon after core formation had ceased [1], which for Earth probably postdated the giant Moon-forming impact. Ancient isolated domains in Earth's mantle - such as the source of 3.8 Ga Isua basalts - might represent mantle isolated from late accreted material, as suggested based on their small 182W excesses compared to Earth's present-day mantle [2]. However, such 182W excesses may also represent signatures of early differentiation in Earth's mantle, which have been preserved through the giant impact [3]. To assess the origin of 182W anomalies and the 182W composition of the pre-late veneer mantle, we determined HSE abundances and 182W compositions of a suite of mafic to ultramafic rocks from Isua. Our data show that the Isua source mantle had HSE abundances at ~60% of the present-day mantle, inconsistent with isolation from the late veneer. For the same samples we obtained a 13±4 ppm 182W excess over the modern terrestrial mantle, in excellent agreement with previous data [2]. Using a range of possible late veneer compositions and taking into account the recently revised 182W value for the Moon [4], we calculate that the Isua mantle source, containing 60% late veneer, would have a 182W value of 9±4 ppm, in very good agreement with the measured value for Isua. The combined HSE-W data, therefore, are consistent with only partial addition of the late veneer to the Isua mantle source, and with the interpretation that the 27±4 ppm 182W excess of the Moon represents the 182W composition of the pre-late veneer Earth's mantle [4]. [1] Dale et al. (2012) Science 336, 72. [2] Willbold et al. (2011) Nature 477, 195. [3] Touboul et al. (2012) Science 335, 1065-1069. [4] Kruijer et al. (2015) Nature 7548, 534

  13. [Phenomenon of dental fear].

    PubMed

    Moore, R; Birn, H

    1990-01-01

    Odontophobia is a rather unique phobia with special psychosomatic components that impact on the dental health of odontophobic persons. It also has psychosocial components largely as a result of destruction of the teeth and subsequent embarrassment that can affect a person and cause a vicious cycle of dental fear. The phenomenon is facilitated by misunderstandings and myths generated by both patients and dentists. The most common reasons given in the literature for such strong fears of dental treatment are: 1) bad experiences in childhood for 85% of cases, 2) feeling of powerlessness and lack of control over personal emotional reactions and over the social situation in the dental chair, 3) social learning processes in which the image of the dentist is cast in a negative light by the mass media or by the person's relatives or friends and 4) that the person has other psychologic problems (in 20% of cases), such as serious phobias and/or neuroses. A strategy of researching and thus tackling the problem is presented which focuses on three essential targets that require studying and change: 1) the community at large and their image of the dentist, 2) the patient role and 3) the dentist role. Various model projects are presented along with their diagnostic systems. These are seen to focus in varying degrees on different elements of the target groups that effect the dentist-patient relationship but the need to come out into the community and make the social environment right for these patients is an important factor in all strategies.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. Syllabus of Dental Materials

    DTIC Science & Technology

    1984-07-01

    or orthodontic bands. When a cold mixing slab (7 to 210 C) is used, more powder will be incorporated into the liquid and the set of the cement...over the mechanism of action of eugenol upon the dental pulp . Brannstrom and Nyborg (8) have demonstrated that eugenol may have little direct...AND LINERS--WOOLSEY 35 pulp , but may actually kill bacteria in the dentinal tubules and eliminate the source of pulpal irritation which renders the

  15. Dental Assisting Education in California.

    ERIC Educational Resources Information Center

    California State Dept. of Education, Sacramento. Bureau of Industrial Education.

    A survey of 22 dental assisting programs showed an average of 1,124 hours of instruction in dental assisting for 15 four-semester, 955 for three three-semester, and 1,042 for four two-semester programs. The average instructional hours for the four-semester programs were 48 in introduction to dental assisting, 179 in the life sciences, 221 in the…

  16. Allied dental personnel: will there be enough?

    PubMed

    Waldman, H Barry; Perlman, Steven P

    2008-11-01

    The escalating number and size of dental practices mean greater dependency on a ready supply of allied dental personnel. However, despite the increasing number of entry places in allied dental training programs, many places remain unfilled and large numbers of individuals do not complete the course of studies. A review of the changes in dental practice sizes and dental assistant, dental hygienist and dental laboratory technician programs raises concerns as to whether there will be enough allied dental personnel to meet the future needs of the profession. The need for increasing attention to this potential eventuality is stressed.

  17. Influence of a thin veneer of low-hydraulic-conductivity sediment on modelled exchange between river water and groundwater in response to induced infiltration

    USGS Publications Warehouse

    Rosenberry, Donald O.; Healy, Richard W.

    2012-01-01

    A thin layer of fine-grained sediment commonly is deposited at the sediment–water interface of streams and rivers during low-flow conditions, and may hinder exchange at the sediment–water interface similar to that observed at many riverbank-filtration (RBF) sites. Results from a numerical groundwater-flow model indicate that a low-permeability veneer reduces the contribution of river water to a pumping well in a riparian aquifer to various degrees, depending on simulated hydraulic gradients, hydrogeological properties, and pumping conditions. Seepage of river water is reduced by 5–10% when a 2-cm thick, low-permeability veneer is present on the bed surface. Increasing thickness of the low-permeability layer to 0·1 m has little effect on distribution of seepage or percentage contribution from the river to the pumping well. A three-orders-of-magnitude reduction in hydraulic conductivity of the veneer is required to reduce seepage from the river to the extent typically associated with clogging at RBF sites. This degree of reduction is much larger than field-measured values that were on the order of a factor of 20–25. Over 90% of seepage occurs within 12 m of the shoreline closest to the pumping well for most simulations. Virtually no seepage occurs through the thalweg near the shoreline opposite the pumping well, although no low-permeability sediment was simulated for the thalweg. These results are relevant to natural settings that favour formation of a substantial, low-permeability sediment veneer, as well as central-pivot irrigation systems, and municipal water supplies where river seepage is induced via pumping wells

  18. Evaluation of the effect of surface preparation using phosphoric acid and luting cement on the flexural strength of porcelain laminate veneering material

    PubMed Central

    Guruprasada; Rivankar, N.; Dhiman, R.K.; Viswambaran, M.

    2015-01-01

    Background Conventionally HF acid has been used for etching ceramic veneer restorations before their cementation. Studies are lacking regarding the effectiveness of phosphoric acid as a substitute for HF acid for etching the ceramic veneers. The purpose of this study was to evaluate the effectiveness of surface preparation of porcelain laminate veneers using phosphoric acid, as compared to HF acid etching in providing the necessary surface roughness conducive to development of an effective bond between the ceramic laminate and the resin luting cement. Methods 210 porcelain discs of 15 mm diameter and 0.9 mm thickness were prepared. These study samples were divided into seven groups of thirty samples each. Surfaces of the first (control) and the second group of samples were not prepared. The surfaces of other five groups were prepared with different surface treatments. Further all the groups of specimens were coated with a layer of resin luting cement. Flexural strength of each specimen was determined using universal testing machine and the results were compared. Results The combination surface treatment using alumina surface abrasion followed by etching with phosphoric acid provided the highest flexural strength with the mean flexural strength of 101.11 MPa, followed by alumina surface abrasion (95.41 MPa), and phosphoric acid surface etching (81.68 MPa). Conclusion Laminate veneers surface treated using 50 μm alumina abrasion followed by etching with phosphoric acid showed the highest flexural strengths after resin coating compared to other groups. PMID:26843743

  19. Thermal/mechanical simulation and laboratory fatigue testing of an alternative yttria tetragonal zirconia polycrystal core-veneer all-ceramic layered crown design.

    PubMed

    Bonfante, Estevam A; Rafferty, Brian; Zavanelli, Ricardo A; Silva, Nelson R F A; Rekow, Elizabeth D; Thompson, Van P; Coelho, Paulo G

    2010-04-01

    This study evaluated the stress levels at the core layer and the veneer layer of zirconia crowns (comprising an alternative core design vs. a standard core design) under mechanical/thermal simulation, and subjected simulated models to laboratory mouth-motion fatigue. The dimensions of a mandibular first molar were imported into computer-aided design (CAD) software and a tooth preparation was modeled. A crown was designed using the space between the original tooth and the prepared tooth. The alternative core presented an additional lingual shoulder that lowered the veneer bulk of the cusps. Finite element analyses evaluated the residual maximum principal stresses fields at the core and veneer of both designs under loading and when cooled from 900 degrees C to 25 degrees C. Crowns were fabricated and mouth-motion fatigued, generating master Weibull curves and reliability data. Thermal modeling showed low residual stress fields throughout the bulk of the cusps for both groups. Mechanical simulation depicted a shift in stress levels to the core of the alternative design compared with the standard design. Significantly higher reliability was found for the alternative core. Regardless of the alternative configuration, thermal and mechanical computer simulations showed stress in the alternative core design comparable and higher to that of the standard configuration, respectively. Such a mechanical scenario probably led to the higher reliability of the alternative design under fatigue.

  20. Using acoustic sensors to improve the efficiency of the forest value chain in Canada: a case study with laminated veneer lumber.

    PubMed

    Achim, Alexis; Paradis, Normand; Carter, Peter; Hernández, Roger E

    2011-01-01

    Engineered wood products for structural use must meet minimum strength and stiffness criteria. This represents a major challenge for the industry as the mechanical properties of the wood resource are inherently variable. We report on a case study that was conducted in a laminated veneer lumber (LVL) mill in order to test the potential of an acoustic sensor to predict structural properties of the wood resource prior to processing. A population of 266 recently harvested aspen logs were segregated into three sub-populations based on measurements of longitudinal acoustic speed in wood using a hand tool equipped with a resonance-based acoustic sensor. Each of the three sub-populations were peeled into veneer sheets and graded for stiffness with an ultrasonic device. The average ultrasonic propagation time (UPT) of each subpopulation was 418, 440 and 453 microseconds for the green, blue, and red populations, respectively. This resulted in contrasting proportions of structural veneer grades, indicating that the efficiency of the forest value chain could be improved using acoustic sensors. A linear regression analysis also showed that the dynamic modulus of elasticity (MOE) of LVL was strongly related to static MOE (R(2) = 0.83), which suggests that acoustic tools may be used for quality control during the production process.

  1. Using Acoustic Sensors to Improve the Efficiency of the Forest Value Chain in Canada: A Case Study with Laminated Veneer Lumber

    PubMed Central

    Achim, Alexis; Paradis, Normand; Carter, Peter; Hernández, Roger E.

    2011-01-01

    Engineered wood products for structural use must meet minimum strength and stiffness criteria. This represents a major challenge for the industry as the mechanical properties of the wood resource are inherently variable. We report on a case study that was conducted in a laminated veneer lumber (LVL) mill in order to test the potential of an acoustic sensor to predict structural properties of the wood resource prior to processing. A population of 266 recently harvested aspen logs were segregated into three sub-populations based on measurements of longitudinal acoustic speed in wood using a hand tool equipped with a resonance-based acoustic sensor. Each of the three sub-populations were peeled into veneer sheets and graded for stiffness with an ultrasonic device. The average ultrasonic propagation time (UPT) of each subpopulation was 418, 440 and 453 microseconds for the green, blue, and red populations, respectively. This resulted in contrasting proportions of structural veneer grades, indicating that the efficiency of the forest value chain could be improved using acoustic sensors. A linear regression analysis also showed that the dynamic modulus of elasticity (MOE) of LVL was strongly related to static MOE (R2 = 0.83), which suggests that acoustic tools may be used for quality control during the production process. PMID:22163922

  2. The 24-year clinical performance of porcelain laminate veneer restorations bonded with a two-liquid silane primer and a tri-n-butylborane-initiated adhesive resin.

    PubMed

    Nakamura, Mitsuo; Matsumura, Hideo

    2014-09-01

    This report describes the bonding technique and clinical course of porcelain laminate veneer restorations applied to discolored maxillary incisors and canines. The patient was an 18-year-old woman, and tooth reduction was limited to the enamel. Laminate veneer restorations were made with a feldspathic porcelain material (Cosmotech Porcelain). After try-in, enamel surfaces were etched with 65% phosphoric acid gel, and a tri-n-butylborane-initiated resin (Super-Bond C&B) was applied as a bonding agent. The inner surface of the restorations was etched with 5% hydrofluoric acid gel (HF Gel) and treated with a two-liquid silane primer (Porcelain Liner M), after which the Super-Bond resin was applied. Each restoration was seated with a dual-activated composite luting agent (Cosmotech Composite). After 24 years and 8 months, the restorations are functioning satisfactorily. The luting system and bonding technique described in this report are an option for seating laminate veneer restorations made of silica-based tooth-colored ceramics.

  3. Chipping resistance of graded zirconia ceramics for dental crowns.

    PubMed

    Zhang, Y; Chai, H; Lee, J J-W; Lawn, B R

    2012-03-01

    A serious drawback of veneering porcelains is a pronounced susceptibility to chipping. Glass-infiltrated dense zirconia structures can now be produced with esthetic quality, making them an attractive alternative. In this study, we examined the hypothesis that such infiltrated structures are much more chip-resistant than conventional porcelains, and at least as chip-resistant as non-infiltrated zirconia. A sharp indenter was used to produce chips in flat and anatomically correct glass-infiltrated zirconia crown materials, and critical loads were measured as a function of distance from the specimen edge (flat) or side wall (crown). Control data were obtained on zirconia specimens without infiltration and on crowns veneered with porcelains. The results confirmed that the resistance to chipping in graded zirconia is more than 4 times higher than that of porcelain-veneered zirconia and is at least as high as that of non-veneered zirconia.

  4. Competency in Allied Dental Education.

    ERIC Educational Resources Information Center

    Beemsterboer, P. L.

    1994-01-01

    Implications of competency-based education for dental assistants and hygienists are examined. Such an approach would provide assistance in defining evolving roles in delivery of dental care; help in defining national competencies and analyzing appropriateness of current care; and a mechanism for developing curriculum that responds to community…

  5. Dental Assisting Competencies. Final Report.

    ERIC Educational Resources Information Center

    Richards, Beverly; And Others

    This document contains dental assisting competencies and competency-based performance objectives, learning activities, resources, and evaluation procedures for each competency that was adapted and developed by instructors of dental assisting to suit the needs and legal parameters of Pennsylvania. The competencies and associated elements are…

  6. Clinical Guidelines. Dental Hygiene Program.

    ERIC Educational Resources Information Center

    Branson, Bonnie

    This manual contains information concerning the policies and procedures of the Southern Illinois University-Carbondale Dental Hygiene Clinic. The manual is presented in a question/answer format for the information and convenience of dental hygiene students in the program, and is intended to answer their questions concerning clinical policies and…

  7. Medical screenings in dental settings.

    PubMed

    Bowen, Denise M

    2012-01-01

    The purpose of Linking Research to Clinical Practice is to present evidence based information to clinical dental hygienists so that they can make informed decisions regarding patient treatment and recommendations. Each issue will feature a different topic area of importance to clinical dental hygienists with A BOTTOM LINE to translate the research findings into clinical application.

  8. Dentistry and Dental Hygiene Handbook.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Office of the Professions.

    A reference guide to laws, rules, and regulations that govern dentistry and dental hygiene practice in New York State is presented. In addition to identifying licensing requirements/procedures for dentists and dental hygienists, general provisions of Title VIII of the Education Law are covered, along with state management, professional misconduct,…

  9. Dentistry and Dental Hygiene Handbook.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Office of the Professions.

    The handbook contains laws, rules, and regulations of the New York State Education Department that govern dentistry and dental hygiene practice in the state. It describes licensure requirements and includes complete application forms and instructions for obtaining license and first registration as a dentist and dental hygienist. Applicants are…

  10. Music interventions for dental anxiety.

    PubMed

    Bradt, J; Teague, A

    2016-11-25

    Anxiety is a significant issue in the dental care of adults and children. Dental anxiety often leads to avoidance of dental care which may result in significant deterioration of oral and dental health. Non-pharmacological anxiety management interventions such as music listening are increasingly used in dental care. Although efficacy for music's anxiolytic effects has been established for pre-operative anxiety, findings regarding the use of music listening for dental anxiety are inconclusive, especially for children. The use of music for passive distraction may not be adequate for children and highly anxious adults. Instead, interventions offered by a trained music therapist may be needed to optimize music's anxiolytic impact. Music therapy interventions are individualized to the patient's presenting needs and geared at enhancing patients' active engagement in the management of their anxiety. Interventions may include (i) active refocusing of attention, (ii) music-guided deep breathing, (iii) music-assisted relaxation, and (iv) music-guided imagery. In addition, music therapists can teach patients music-based anxiety management skills prior to dental treatments, offer them the opportunity to express emotions related to the upcoming procedure, and help them gain a sense of control and safety. Clinical guidelines for the use of music listening by dental practitioners are offered.

  11. Dental Laboratory Technology Program Guide.

    ERIC Educational Resources Information Center

    Georgia Univ., Athens. Dept. of Vocational Education.

    This program guide contains the standard dental laboratory technology curriculum for both diploma programs and associate degree programs in technical institutes in Georgia. The curriculum encompasses the minimum competencies required for entry-level workers in the dental laboratory technology field. The general information section contains the…

  12. Dental problems in epileptic patients.

    PubMed

    Zioło, Anna; Mielnik-Błaszczak, Maria

    2004-01-01

    On the grounds of literature and own clinical experience, pathological changes in epilepitic patients have been described. Dental management procedures in these patients have also been presented. The unquestionable importance of prophylaxis, which may markedly minimize the impact of epilepsy on the incidence of mouth diseases, has been emphasised. It has also been stated that epileptic patients should receive specialised and integrated dental treatment.

  13. Dosimetric considerations in dental applications

    NASA Technical Reports Server (NTRS)

    Goble, J. C.

    1978-01-01

    The integration of the Lixiscope into dental procedures was studied and compared with conventional dental radiographic techniques. It was found that through the use of intraoral sealed sources in conjunction with microchannel plate technology, the Lixiscope gives increased diagnostic information with decreased radiation dosage.

  14. Dental Chairside Technique. Student's Manual.

    ERIC Educational Resources Information Center

    Apfel, Maura; Weaver, Trudy Karlene

    This manual is part of a series dealing with skills and information needed by students in dental assisting. The individualized student materials are suitable for classroom, laboratory, or cooperative training programs. This student manual contains four units covering the following topics: local anesthesia; dental office emergencies; oral hygiene;…

  15. Chemical intensification of dental radiographs

    SciTech Connect

    Price, C.

    1983-04-01

    The potential applications of chemical intensification in dental radiography are explored. Three standard photographic intensifiers and three methods designed for radiographic use are evaluated. One of these methods is shown to be capable of reducing radiation dose to one half, without loss of diagnostic quality. Further work is necessary to achieve a system sufficiently practicable to deserve widespread use in routine clinical dental radiography.

  16. Health Instruction Packages: Dental Assisting.

    ERIC Educational Resources Information Center

    McEnery, Paula

    Text, illustrations, and exercises are utilized in this set of four learning modules to instruct dental assisting students in various office skills. The first module, "Dental Office Telephone Techniques," examines the qualities of a good telephone voice and demeanor and provides guidelines for taking a message and handling various…

  17. Nanotechnology for dental implants.

    PubMed

    Tomsia, Antoni P; Lee, Janice S; Wegst, Ulrike G K; Saiz, Eduardo

    2013-01-01

    With the advent of nanotechnology, an opportunity exists for the engineering of new dental implant materials. Metallic dental implants have been successfully used for decades, but they have shortcomings related to osseointegration and mechanical properties that do not match those of bone. Absent the development of an entirely new class of materials, faster osseointegration of currently available dental implants can be accomplished by various surface modifications. To date, there is no consensus regarding the preferred method(s) of implant surface modification, and further development will be required before the ideal implant surface can be created, let alone become available for clinical use. Current approaches can generally be categorized into three areas: ceramic coatings, surface functionalization, and patterning on the micro- to nanoscale. The distinctions among these are imprecise, as some or all of these approaches can be combined to improve in vivo implant performance. These surface improvements have resulted in durable implants with a high percentage of success and long-term function. Nanotechnology has provided another set of opportunities for the manipulation of implant surfaces in its capacity to mimic the surface topography formed by extracellular matrix components of natural tissue. The possibilities introduced by nanotechnology now permit the tailoring of implant chemistry and structure with an unprecedented degree of control. For the first time, tools are available that can be used to manipulate the physicochemical environment and monitor key cellular events at the molecular level. These new tools and capabilities will result in faster bone formation, reduced healing time, and rapid recovery to function.

  18. Current trends in dental implants

    PubMed Central

    Gaviria, Laura; Salcido, John Paul; Guda, Teja

    2014-01-01

    Tooth loss is very a very common problem; therefore, the use of dental implants is also a common practice. Although research on dental implant designs, materials and techniques has increased in the past few years and is expected to expand in the future, there is still a lot of work involved in the use of better biomaterials, implant design, surface modification and functionalization of surfaces to improve the long-term outcomes of the treatment. This paper provides a brief history and evolution of dental implants. It also describes the types of implants that have been developed, and the parameters that are presently used in the design of dental implants. Finally, it describes the trends that are employed to improve dental implant surfaces, and current technologies used for the analysis and design of the implants. PMID:24868501

  19. Biostatistical consultation for dental research.

    PubMed

    Clive, Jonathan

    2002-01-01

    Dental science researchers do not really need a detailed, ready-at-hand knowledge of statistics to design and perform high quality scientific research. Although the acquisition and utilization of such knowledge by dental researchers is not discouraged, it is proposed that it is more important for dental researchers to be committed to developing and maintaining a long term, ongoing, interactive consulting relationship with a biostatistician. The nature of this relationship will depend in large part on the complexity of the dental research being conducted. While the statistical consultant will assist in interpreting analytic results for the dental researcher, the latter will need to provide extensive input in assisting in the estimation of sample size and power, and for expressing scientific hypotheses in statistical terms so that the appropriate data analytic methodology can be specified.

  20. The american dental dream.

    PubMed

    Hodges, Nathan

    2015-01-01

    The American Dental Dream-the cultural desire for straight, white teeth-is difficult, if not impossible, for poor and working-class people to achieve. Using ethnographic fiction, autoethnography, poetry, and qualitative interviewing, I brush away the taken-for-granted assumptions about teeth. I explore the personal, relational, and structural consequences of this cultural desire, and show how social class writes itself on our bodies. I write these culture-centered teeth tales to show how one might cope with their teeth.

  1. Lasers In Dental Diagnosis

    NASA Astrophysics Data System (ADS)

    Everse, K. E.; Sinor, T. W.; Menzel, E. R.

    1987-01-01

    We have investigated the potential of lasers for real time in situ dental diagnosis via transillumination of teeth and gums and via fluorescence. Not surprisingly, absorption and/or scattering of light by teeth was found to be insensitive to light color. However, monochromatic transillumination revealed detail better than white light. Transillumination of gums was best performed with orange-red light because of tissue absorption. Illumination of oral structures by 488 nm Ar-laser light was effective in revealing diagnosis detail by fluorescence. Incipient caries and fine tooth fracture lines that are generally not revealed by radiography were observable by laser.

  2. Dental impression materials.

    PubMed

    Perry, Rachel

    2013-01-01

    It is clear that many impression materials are available to the veterinary dentist. They each have different inherent properties, handling characteristics, and indications for use. A thorough understanding of these concepts is essential if the veterinarian and laboratory technician are to produce meaningful and accurate reproductions of oral structures. New products are constantly being introduced to the dental market, with fantastic claims for ease of use and reproduction of detail. The reader is urged to seek independent research findings when assessing such claims, and make decisions founded in the highest possible levels of evidence.

  3. Dental, Dental Hygiene, and Graduate Students' and Faculty Perspectives on Dental Hygienists' Professional Role and the Potential Contribution of a Peer Teaching Program.

    PubMed

    McComas, Martha J; Inglehart, Marita R

    2016-09-01

    The changing role of dental hygienists deserves dental and dental hygiene educators' attention. The first aim of this survey study was to assess University of Michigan dental, dental hygiene, and graduate students' and faculty members' perceptions of dental hygienists' roles; their attitudes and behaviors related to clinical interactions between dental and dental hygiene students; and perceived benefits of engaging dental hygiene students as peer teachers for dental students. The second aim was to assess whether one group of dental students' experiences with dental hygiene student peer teaching affected their perceptions of the dental hygiene profession. Survey respondents were 57 dental hygiene students in all three years of the program (response rate 60% to 100%); 476 dental students in all four years (response rate 56% to 100%); 28 dental and dental hygiene graduate students (response rate 28%); and 67 dental and dental hygiene faculty members (response rate 56%). Compared to the other groups, dental students reported the lowest average number of services dental hygienists can provide (p≤0.001) and the lowest average number of patient groups for which dental hygienists can provide periodontal care (p<0.001). Dental students also had the least positive attitudes about clinical interactions between dental hygiene and dental students (p<0.001) and perceived the fewest benefits of dental hygiene student peer teaching (p<0.001) before experiencing peer teaching. After experiencing dental hygiene student peer teaching, the dental students' perceptions of dental hygienists' roles, attitudes about clinical interactions with dental hygienists, and perceived benefits of dental hygiene student peer teachers improved and were more positive than the responses of their peers with no peer teaching experiences. These results suggest that dental hygiene student peer teaching may improve dental students' perceptions of dental hygienists' roles and attitudes about

  4. The Prevalence of Dental Anxiety in Patients of a University Dental Clinic

    ERIC Educational Resources Information Center

    Woodmansey, Karl F.

    2005-01-01

    Dental anxiety remains a pervasive barrier to dental treatment for many individuals, including college-age patients. In this article, the author reviews dental anxiety and examines the usefulness of assessment instruments for identifying dental anxiety. Using 2 unique assessment instruments, he examines the prevalence of dental anxiety in his…

  5. Status of the Predoctoral Dental Education Program and Its Impact on Graduate Dental Education.

    ERIC Educational Resources Information Center

    Allen, Don L.

    1980-01-01

    The status of the current predoctoral dental program and its relationship to graduate dental education is described. Factors that have influenced the dental curriculum and major changes that have occurred are presented. Major issues facing dental education are outlined. A proposal is presented for greater flexibility in dental education.…

  6. Undergraduate dental English education in Japanese dental schools.

    PubMed

    Rodis, Omar M M; Matsumura, Seishi; Kariya, Naoyuki; Nishimura, Michiko; Yoshida, Toshiko

    2013-05-01

    Dental schools in Japan are among many worldwide whose medium of instruction is not in English. With advances in science, technology, and communication, the demand for the globalization of professions increases. At present, dental schools in Asia, the Middle East, and Europe have started revising their dental curricula to either include English courses for dentistry or offer a full English dental curriculum. In Japan, dental English courses started to be introduced into curricula in the early 1990s. However, a survey conducted in 1999 found that English courses were not offered in Japan's twenty-nine dental schools and there was no consensus as to what such courses should include or when and how they should be taught. Ten years after that survey, the survey results reported in this article found that the problems reported in the 1999 survey still exist. Additionally, there are still differences among schools offering English courses in terms of the timing and contents of the courses. Since teachers and school officials will have an important role in curriculum development, this article recommends that a fact-finding meeting with educators, school, and education officials be initiated to discuss, develop, and implement a core curriculum for these dental English courses.

  7. Trends in Dentistry and Dental Education.

    ERIC Educational Resources Information Center

    Valachovic, Richard W.; Weaver, Richard G.; Sinkford, Jeanne C.; Haden, N. Karl

    2001-01-01

    Compiled from many of the surveys that the American Dental Education Association routinely publishes, along with data from surveys conducted by the American Dental Association and U.S. Department of Health and Human Services, presents statistical tables and descriptive text on trends among dental patients, among dental practitioners, and in dental…

  8. Dental photography today. Part 1: basic concepts

    PubMed Central

    CASAGLIA, A.; DE DOMINICIS, P.; ARCURI, L.; GARGARI, M.; OTTRIA, L.

    2015-01-01

    SUMMARY This paper is the first article in a new series on digital dental photography. Part 1 defines the aims and objectives of dental photography for examination, diagnosis and treatment planning, legal and forensic documentation, publishing, education, marketing and communication with patients, dental team members, colleagues and dental laboratory. PMID:28042424

  9. 21 CFR 872.3275 - Dental cement.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Dental cement. 872.3275 Section 872.3275 Food and... DENTAL DEVICES Prosthetic Devices § 872.3275 Dental cement. (a) Zinc oxide-eugenol—(1) Identification... filling or as a base cement to affix a temporary tooth filling, to affix dental devices such as crowns...

  10. 21 CFR 872.3275 - Dental cement.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Dental cement. 872.3275 Section 872.3275 Food and... DENTAL DEVICES Prosthetic Devices § 872.3275 Dental cement. (a) Zinc oxide-eugenol—(1) Identification... filling or as a base cement to affix a temporary tooth filling, to affix dental devices such as crowns...

  11. 21 CFR 872.3275 - Dental cement.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Dental cement. 872.3275 Section 872.3275 Food and... DENTAL DEVICES Prosthetic Devices § 872.3275 Dental cement. (a) Zinc oxide-eugenol—(1) Identification... filling or as a base cement to affix a temporary tooth filling, to affix dental devices such as crowns...

  12. 21 CFR 872.3275 - Dental cement.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Dental cement. 872.3275 Section 872.3275 Food and... DENTAL DEVICES Prosthetic Devices § 872.3275 Dental cement. (a) Zinc oxide-eugenol—(1) Identification... filling or as a base cement to affix a temporary tooth filling, to affix dental devices such as crowns...

  13. 21 CFR 872.3100 - Dental amalgamator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... is intended for filling dental caries. (b) Classification. Class I (general controls). The device is... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Dental amalgamator. 872.3100 Section 872.3100 Food... DEVICES DENTAL DEVICES Prosthetic Devices § 872.3100 Dental amalgamator. (a) Identification. A...

  14. Involving Parents in Their Children's Dental Care.

    ERIC Educational Resources Information Center

    Becker, Donna

    1998-01-01

    Asserts that parent education is vital to good dental hygiene for the whole family. Discusses what Head Start staffers can do to ensure that children's dental needs are being met, particularly in assisting parents with taking responsibility for children's dental hygiene. Covers dental care tips for parents, questions and answers about dental…

  15. Dental Curriculum Development in Developing Countries.

    ERIC Educational Resources Information Center

    Phantumvanit, Prathip

    1996-01-01

    Since establishment of formal dental education in Southeast Asia, changes stemming from research and technology have led to dental curriculum changes. Development of the dental curriculum can be divided into three phases: disease oriented; health oriented; and community oriented. Evolution of these phases is traced in the dental curricula of Laos,…

  16. 21 CFR 872.3275 - Dental cement.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Dental cement. 872.3275 Section 872.3275 Food and... DENTAL DEVICES Prosthetic Devices § 872.3275 Dental cement. (a) Zinc oxide-eugenol—(1) Identification... filling or as a base cement to affix a temporary tooth filling, to affix dental devices such as crowns...

  17. Sources of Dental Health Teaching Aids.

    ERIC Educational Resources Information Center

    Crawford, Jean H.

    1982-01-01

    Sources of dental health education teaching aids which are available for free or at minimal cost include: (1) The American Dental Health Association; (2) state and local departments of public health; (3) schools of dentistry, dental hygiene, and dental assisting; and (4) the Educator's International Guide. (JN)

  18. 21 CFR 872.3700 - Dental mercury.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Dental mercury. 872.3700 Section 872.3700 Food and... DENTAL DEVICES Prosthetic Devices § 872.3700 Dental mercury. (a) Identification. Dental mercury is a device composed of mercury intended for use as a component of amalgam alloy in the restoration of...

  19. 21 CFR 872.3100 - Dental amalgamator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... is intended for filling dental caries. (b) Classification. Class I (general controls). The device is... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Dental amalgamator. 872.3100 Section 872.3100 Food... DEVICES DENTAL DEVICES Prosthetic Devices § 872.3100 Dental amalgamator. (a) Identification. A...

  20. 21 CFR 872.3100 - Dental amalgamator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... is intended for filling dental caries. (b) Classification. Class I (general controls). The device is... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Dental amalgamator. 872.3100 Section 872.3100 Food... DEVICES DENTAL DEVICES Prosthetic Devices § 872.3100 Dental amalgamator. (a) Identification. A...

  1. 21 CFR 872.3100 - Dental amalgamator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... is intended for filling dental caries. (b) Classification. Class I (general controls). The device is... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Dental amalgamator. 872.3100 Section 872.3100 Food... DEVICES DENTAL DEVICES Prosthetic Devices § 872.3100 Dental amalgamator. (a) Identification. A...

  2. 21 CFR 872.3100 - Dental amalgamator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... is intended for filling dental caries. (b) Classification. Class I (general controls). The device is... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Dental amalgamator. 872.3100 Section 872.3100 Food... DEVICES DENTAL DEVICES Prosthetic Devices § 872.3100 Dental amalgamator. (a) Identification. A...

  3. Dental coping strategies, general anxiety, and depression among adult patients with dental anxiety but with different dental-attendance patterns.

    PubMed

    Bernson, Jenny M; Elfström, Magnus L; Hakeberg, Magnus

    2013-06-01

    The aim of the present study was to investigate dental coping strategies, general anxiety, and depression in relation to regularity of dental treatment among persons with either regular dental care or phobic avoidance, whilst controlling for sociodemographic factors. Psychometric questionnaires on dental anxiety, dental coping strategies, general anxiety, and depression were delivered to 263 adult patients with dental phobic avoidance behavior who were seeking help from a specialized dental fear clinic and to 141 adult patients with dental anxiety who were receiving regular dental care from various public dental clinics. The results showed that the levels of dental and general anxiety and of depression were significantly higher among irregular attendees compared with regular attendees. Irregular attendees admitted fewer adaptive coping strategies. Predictive of irregular dental care were gender, dental anxiety, general anxiety, and the nonuse of the coping strategy 'optimism'. This study further confirms earlier preliminary results that the use of optimistic thinking is predictive for regular dental attendance habits and that male gender is a risk factor for irregular attendance. Moreover, this study adds that a high level of general anxiety indicates a higher risk for irregular dental care.

  4. A simplified impression technique for dental implants.

    PubMed

    Vogel, Robert E

    2002-03-01

    Dental implants have been considered an acceptable form of dental treatment since the early 1980s. A number of studies have been published describing impression techniques for dental implants. Many of the techniques described are so complex that they may seem daunting to the average restorative dentist. Most general practitioners do not wish to attempt to restore dental implants. This article describes a very simple, yet extremely accurate, technique for making impressions of dental implant fixtures.

  5. A Survey of Civilian Dental Computer Systems.

    DTIC Science & Technology

    1988-01-01

    r.arketplace, the orthodontic community continued to pioneer clinical automation through diagnosis, treat- (1) patient registration, identification...profession." New York State Dental Journal 34:76, 1968. 17. Ehrlich, A., The Role of Computers in Dental Practice Management. Champaign, IL: Colwell...Council on Dental military dental clinic. Medical Bulletin of the US Army Practice. Report: Dental Computer Vendors. 1984 Europe 39:14-16, 1982. 19

  6. Surface photo-discoloration and degradation of dyed wood veneer exposed to different wavelengths of artificial light

    NASA Astrophysics Data System (ADS)

    Liu, Yi; Shao, Lingmin; Gao, Jianmin; Guo, Hongwu; Chen, Yao; Cheng, Qingzheng; Via, Brian K.

    2015-03-01

    The surface of dyed wood is prone to discoloration when exposed to light irradiation which significantly decreases its decorative effect and shortens its service life. The influence of light wavelength exposure to the surface of dyed wood was investigated to study the effect on discoloration and degradation. Acid Blue V and Acid Red GR dyed wood veneers were subjected to light exposure with different wavelengths from the UV to visible region (254-420 nm). Results showed that the surface discoloration of dyed wood was linearly related to lignin concentration and dyes degradation and the consequent transformation of chromophoric groups such as aromatic (Cdbnd C) and carbonyl (Cdbnd O) through methoxy reaction. The dyes, lignin and some active constituents were degraded severely, even at short exposures. Acid Blue V dyed wood exhibited greater discoloration than the Acid Red GR treatment. The reflectance and K/S absorption curve showed a hypochromic effect on the dyed wood surface. The dyes and wood chemical structure played a complex and combined role on the selective absorption of different wavelengths of light. The color change rate was apparent with 254 nm exposure in the initial stages, but a greater discoloration rate occurred on the samples irradiated at 313 and 340 nm than at 254 and 420 nm with the time prolonged. The degradation rate and degree of discoloration correlated well with the light energy and wavelength.

  7. Initial dental needs and a projection of needed dental capacity in the Iowa Department of Corrections.

    PubMed

    Ringgenberg, Wendy J

    2011-04-01

    The dental health data for the Iowa Department of Corrections (IDOC) inmate population were analyzed to better understand dental health issues experienced by inmates and IDOC's system for responding to those dental needs. Each inmate is given a dental health assessment upon admission to Iowa's prison system. These data were analyzed for frequency of dental health needs and frequency of dental health services. In addition, emergency dental health services were analyzed. The findings show that each inmate has approximately 7.6 dental codes, including the initial exam, dental services provided, and dental needs not yet addressed. When reviewing only dental needs (and not the initial exam), 32% (5,110) identified dental needs were completed and 66% (10,572) were not.

  8. Roughness Measurement of Dental Materials

    NASA Astrophysics Data System (ADS)

    Shulev, Assen; Roussev, Ilia; Karpuzov, Simeon; Stoilov, Georgi; Ignatova, Detelina; See, Constantin von; Mitov, Gergo

    2016-06-01

    This paper presents a roughness measurement of zirconia ceramics, widely used for dental applications. Surface roughness variations caused by the most commonly used dental instruments for intraoral grinding and polishing are estimated. The applied technique is simple and utilizes the speckle properties of the scattered laser light. It could be easily implemented even in dental clinic environment. The main criteria for roughness estimation is the average speckle size, which varies with the roughness of zirconia. The algorithm used for the speckle size estimation is based on the normalized autocorrelation approach.

  9. [Allergies to dental materials and dental pharmacologic agents].

    PubMed

    Gall, H

    1983-07-01

    Allergic reactions to dental materials and remedies cause stomatitis in the patient and a contact dermatitis in the dental personnel. Topical contact (acrylic resin denture materials, heat accumulation, plaques on the denture) and endogenic (symptom of internal and psychiatric illnesses) factors are the cause for denture sore mouth. In metallic alloys corrosions and electric currents can effect an irritation to the oral mucosa. The application of amalgam fillings can possibly result in a mercurialism. Dental remedies used for treatment of wounds and dental roots are potent sensitizers. Surface anesthetics with tetracaine are the most frequent contact allergens for dentists. Injectable local anesthetics produce anaphylactic type reactions as well as toxic side-effects in the patient.

  10. Do dental students cheat?

    PubMed

    Fuller, J L; Killip, D E

    1979-12-01

    In a questionnaire survey, dental students from all four classes at The University of Iowa College of Dentistry were asked if they had cheated during their first and second years. They were then asked if they believed that others cheated. Cheating was admitted to by 43 percent of the respondents, but 94 percent believed it was occurring. Plagiarism was delineated as a form of cheating; while fewer students admitted to its use, the reported occurrence should be of concern in technique courses. Responses were analyzed both by year in school and grade point average. Reasons for cheating were described; and some conditions conducive to cheating were found to be under the control of the instructor.

  11. Dental Arch Wire

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Straightening teeth is an arduous process requiring months, often years, of applying corrective pressure by means of arch wires-better known as brace-which may have to be changed several times in the course of treatment. A new method has been developed by Dr. George Andreasen, orthodontist and dental scientist at the University of Iowa. The key is a new type of arch wire material, called Nitinol, with exceptional elasticity which helps reduce the required number of brace changes. An alloy of nickel and titanium, Nitinol was originally developed for aerospace applications by the Naval Ordnance Laboratory, now the Naval Surface Weapons Laboratory, White Oaks, Maryland. NASA subsequently conducted additional research on the properties of Nitinol and on procedures for processing the metal.

  12. Epidemiology of dental caries.

    PubMed

    Winter, G B

    1990-01-01

    The most recent epidemiological data on the prevalence of dental caries in children indicate a halting of the increasing levels in many developing countries and a continuing decrease in many highly industrialized countries of the world. However, a further fall in caries levels predicted for 5-yr-old children in the U.K. has not occurred and the decline in caries may have begun to level out. 'Polarization' of caries to a minority of high-risk individuals is occurring in the developed world, with 20-25% of children accounting for more than 50% of the disease. Socio-economic factors are important in determining the proportion of high-risk children in these countries. The multifactorial aetiology of caries allows a number of different interpretations to account for changes in the prevalence of the disease with time, in both the developing and developed countries. These changes are variously ascribed to alterations in dietary habits, especially the consumption of sugar; variations in the patterns of oral hygiene; increased contact with trace elements, especially fluoride, in the environment; changes in the ecology and/or virulence of oral and dental plaque microflora and alterations in the oral protective mechanisms including the immune status. The epidemiological evidence available on the relationship of all these social, environmental and other factors to changes in the prevalence levels of caries does not, however, fully explain all the changes that have been observed. The claim that caries is no longer a public health problem is premature, as it ignores the still high proportion of individuals with tooth decay throughout the world.

  13. Dental Health: The Basic Facts

    MedlinePlus

    ... MS. Resources Academy of General Dentistry 211 East Chicago Avenue Suite 900 Chicago, Illinois 60611 Tel: 888-243-3368 Web site: ... Ask a question American Dental Association 211 East Chicago Avenue Chicago, Illinois 60611 Tel: 312-440-2500 ...

  14. Vocational Interests of Dental Hygienists

    ERIC Educational Resources Information Center

    Ishida, Helen

    1975-01-01

    Using the Strong Vocational Interest Blank, an occupational interest scale for dental hygienists was developed, and comparisons of interests were made between graduates of two- and four-year programs. (Author)

  15. Dental insurance! Are we ready?

    PubMed

    Toor, Ravi S S; Jindal, R

    2011-01-01

    Dental insurance is insurance designed to pay the costs associated with dental care. The Foreign Direct Investment (FDI) bill which was put forward in the winter session of the Lok Sabha (2008) focused on increasing the foreign investment share from the existing 26% to 49% in the insurance companies of India. This will allow the multibillion dollar international insurance companies to enter the Indian market and subsequently cover all aspects of insurance in India. Dental insurance will be an integral a part of this system. Dental insurance is a new concept in Southeast Asia as very few countries in Southeast Asia cover this aspect of insurance. It is important that the dentists in India should be acquainted with the different types of plans these companies are going to offer and about a new relationship which is going to emerge in the coming years between dentist, patient and the insurance company.

  16. Dental abscess: A microbiological review

    PubMed Central

    Shweta; Prakash, S Krishna

    2013-01-01

    Dental abscess is a frequently occurring infectious process known to the health practice. The fate of the infection depends on the virulence of the bacteria, host resistance factors, and regional anatomy. Serious consequences arising from the spread of a dental abscess lead to significant morbidity and mortality. Acute dental abscess is polymicrobial, comprising of strict anaerobes, such as anaerobic cocci, Prevotella, Fusobacterium species, and facultative anaerobes, such as viridans group streptococci and the Streptococcus anginosus group. Numerous novel, uncultivable and fastidious organisms have been identified as potential pathogens with the use of non-culture techniques. The majority of localized dental abscesses respond to surgical treatment while the use of antimicrobials is limited to severe spreading infections. There is a need for good-quality clinical trials of sufficient size to identify the ideal treatment. The microbiology of the acute dentoalveolar abscess and its treatment in the light of improved culture and diagnostic methods are reviewed. PMID:24348613

  17. Dental disease in geriatric horses.

    PubMed

    Lowder, M Q; Mueller, P O

    1998-08-01

    The dental management of geriatric horses can be a rewarding challenge to the practitioner. Owners become dissatisfied when their expectations are unrealistic. Consequently, communication between the owner and the practitioner is essential prior to the start of any dental procedure in a geriatric horse. Owners often expect the practitioner to correct what has been neglected for years. It is critical that the owner understand the possible complications associated with dental procedures and that some procedures (e.g., trephination) may necessitate protracted care. Often, when a tooth has been removed, there is a need for more frequent masticatory examinations to curtail any potential problems (i.e., development of step mouth). The owner needs to be aware of the extra dental maintenance costs that must be included in the upkeep of the horse.

  18. Lip Lifting: Unveiling Dental Beauty.

    PubMed

    Stanley, Kyle; Caligiuri, Matthew; Schlichting, Luís Henrique; Bazos, Panaghiotis K; Magne, Michel

    2017-01-01

    The focus for the achievement of complete success in the esthetic zone has traditionally been on addressing deficiencies of intraoral hard and soft tissue. Often, these deficiencies are accompanied by esthetic concerns regarding the lips that are routinely neglected by the dental team. A predictable plastic surgery technique - the lip lift - has been used for decades to enhance lip esthetics by shortening the senile upper lip to achieve a more youthful appearance. Over the years, this technique has been refined and used in many different ways, allowing its routine incorporation into full facial esthetic planning. Through restoration of the upper lip to its optimal position, the artistry of the dentist and dental technician can truly be appreciated in the rejuvenated smile. By the introduction of this minimally invasive surgical technique to the dental community, patients stand to benefit from a comprehensive orofacial approach to anterior dental esthetic planning.

  19. Clinical Medicine for Dental Students.

    ERIC Educational Resources Information Center

    Stearns, Norman S.; And Others

    1985-01-01

    A program providing instruction in medical topics throughout the dental curriculum at Tufts University is described, and the results of a survey indicating alumni satisfaction with training in physical evaluation techniques and ability to detect medical problems are discussed. (MSE)

  20. Dental management of anticoagulated patients.

    PubMed

    Carr, M M; Mason, R B

    1992-10-01

    Today's trend toward ambulatory medical care will bring more pharmacological problems into the dental office. While the dental management of patients taking oral anticoagulants is controversial, current research supports the contention that they can be safely treated on an outpatient basis. The use of the International Normalized Ratio (INR) has made better estimates of prothrombin time possible, and patients can be maintained in a narrow therapeutic range. Postoperative hemorrhage can be avoided or controlled with local hemostatic agents.

  1. Surface texture measurement for dental wear applications

    NASA Astrophysics Data System (ADS)

    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.

  2. Dental home: Patient centered dentistry

    PubMed Central

    Girish Babu, K. L.; Doddamani, G. M.

    2012-01-01

    Early childhood dental caries occurs in all racial and socioeconomic groups; however, it tends to be more prevalent in children in families belonging to the low-income group, where it is seen in epidemic proportions. Dental caries results from an overgrowth of specific organisms that are a part of normally occurring human flora. Human dental flora is site specific, and an infant is not colonized until the eruption of the primary dentition at approximately 6 to 30 months of age. The most likely source of inoculation of an infant's dental flora is the mother, or another intimate care provider, shared utensils, etc. Decreasing the level of cariogenic organisms in the mother's dental flora at the time of colonization can significantly impact the child's redisposition to caries. To prevent caries in children, high-risk individuals must be identified at an early age (preferably high-risk mothers during prenatal care), and aggressive strategies should be adopted, including anticipatory guidance, behavior modifications (oral hygiene and feeding practices), and establishment of a dental home by 1 year of age for children deemed at risk. PMID:24478960

  3. Dental Attitudes, Perceptions, and Treatment Needs in a University Population.

    ERIC Educational Resources Information Center

    Cohen, Leonard A.; And Others

    1980-01-01

    Dental attitudes of college students were examined: frequency of past visits; subceptibility to dental conditions; seriousness, preventability, and treatability of dental conditions; and satisfaction with dentists, practices, and other dental conditions. (Authors/CJ)

  4. On the interfacial fracture of porcelain/zirconia and graded zirconia dental structures.

    PubMed

    Chai, Herzl; Lee, James J-W; Mieleszko, Adam J; Chu, Stephen J; Zhang, Yu

    2014-08-01

    Porcelain fused to zirconia (PFZ) restorations are widely used in prosthetic dentistry. However, their susceptibility to fracture remains a practical problem. The failure of PFZ prostheses often involves crack initiation and growth in the porcelain, which may be followed by fracture along the porcelain/zirconia (P/Z) interface. In this work, we characterized the process of fracture in two PFZ systems, as well as a newly developed graded glass-zirconia structure with emphases placed on resistance to interfacial cracking. Thin porcelain layers were fused onto Y-TZP plates with or without the presence of a glass binder. The specimens were loaded in a four-point-bending fixture with the thin porcelain veneer in tension, simulating the lower portion of the connectors and marginal areas of a fixed dental prosthesis (FDP) during occlusal loading. The evolution of damage was observed by a video camera. The fracture was characterized by unstable growth of cracks perpendicular to the P/Z interface (channel cracks) in the porcelain layer, which was followed by stable cracking along the P/Z interface. The interfacial fracture energy GC was determined by a finite-element analysis taking into account stress-shielding effects due to the presence of adjacent channel cracks. The resulting GC was considerably less than commonly reported values for similar systems. Fracture in the graded Y-TZP samples occurred via a single channel crack at a much greater stress than for PFZ. No delamination between the residual glass layer and graded zirconia occurred in any of the tests. Combined with its enhanced resistance to edge chipping and good esthetic quality, graded Y-TZP emerges as a viable material concept for dental restorations.

  5. Access to Dental Providers in Pennsylvania

    PubMed Central

    Baird, Matthew D.; Baird, Michelle K.; Vesely, Joseph V.

    2016-01-01

    Abstract Ensuring access to dental care, particularly for children, is a significant policy concern in the United States. Many factors affect access on both the provider and patient sides. This study examines an important factor in the ability to access dental care: the distribution and availability of dental health providers. The authors assess providers across the counties of Pennsylvania, primarily using data from the 2013 Survey of Dentists and Dental Hygienists administered by the Pennsylvania Department of Health. To identify possible dental provider shortages in Pennsylvania counties, the authors assessed ten indicators of access to dental providers. They find significant variation in the indicators across Pennsylvania counties. PMID:28083429

  6. Medical insurance for dental sleep medicine.

    PubMed

    Lipsey, Marty R

    2012-04-01

    Over the last 5 to 7 years, dental teams have mastered the art and science of processing dental insurance for their patients but have major difficulties learning how to help their patients when it comes to medical insurance. This article attempts to provide a basic guide for the dental team in coding, billing, and processing of major medical insurance for dental sleep medicine. Although there is certainly a learning curve for the dental team in this endeavor, the "patient and physician friendly" dental sleep medicine practice is a model that will help to assure growth and success.

  7. All-ceramic inlay-retained fixed partial bridge using a CAD-CAM produced Y-TZP framework and fluoroapatite veneering ceramic: a clinical report.

    PubMed

    Hirata, Ronaldo; Viotti, Ronaldo; Reis, Andre Figueiredo; de Andrade, Oswaldo Scopin

    2007-11-01

    All-ceramic materials have become an excellent option for both anterior and posterior fixed partial dentures (FPDs) due to advances in esthetic and mechanical properties. This clinical report describes the use of an all-ceramic inlay-retained three-unit FPD for replacement of a maxillary second premolar. Prosthetic restorative materials consisted of a CAD-CAM processed presintered yttrium stabilized zirconium oxide (Y-TZP) framework and a fluoroapatite veneering ceramic. The minimally invasive preparation technique and advantages of this highly esthetic and resistant treatment option are discussed.

  8. Costing dental restorations in public sector dental clinics.

    PubMed

    Khairiyah, Abdul Muttalib; Razak, Ishak Abdul; Raja-Latifah, Raja Jalludin; Tan, Bee Siew; Norain, Abu Talib; Noor-Aliyah, Ismail; Natifah, Che Salleh; Rauzi, Ismail

    2009-04-01

    The objective of this study is to share cost analysis methodology and to obtain cost estimates for posterior restorations in public sector dental clinics. Two urban and 2 rural dental clinics in Selangor state were selected. Only cases of 1 posterior restoration per visit by dental officers were included over 6 months. One capsulated amalgam type, 1 capsulated tooth-colored, and 1 non-capsulated tooth-colored material were selected. A clinical pathway form was formulated to collect data per patient. Annual capital and recurrent expenditures were collected per clinic. The mean cost of an amalgam restoration was RM 30.96 (sdRM 7.86); and tooth-colored restorations ranged from RM 33.00 (sdRM 8.43) to RM 41.10 (sdRM 10.61). Wherein 1 USD = RM 2.8. Restoration costs were 35% to 55% higher in clinics in rural areas than in urban areas. The findings demonstrate economy of scale for clinic operation and restoration costs with higher patient load. Costs per restoration were higher in rural than in urban dental clinics. More studies are recommended to address the dearth of dental costs data in Malaysia.

  9. Component analysis of dental porcelain for assisting dental identification.

    PubMed

    Aboshi, H; Takahashi, T; Komuro, T

    2006-12-01

    The fluorescence of porcelain crowns recovered from the mouth of an unknown murder victim, and several control porcelain samples, were examined by fluorescent examination lamps. The fluorescence from two of the control samples was quite similar to that from the porcelain crowns recovered from the victim. To increase the objectivity of the results by quantitative analysis, the composition of each porcelain crown and control sample was also evaluated by wave dispersion X-ray microanalyser. The elements detected from the porcelain crowns of the victim matched those of two of the porcelain samples. Later, the antemortem dental records and radiographs of the victim were obtained through a dentist, who had recognized the name of the porcelain manufacturer in a postmortem dental information request placed on the Japanese Dental Association web page. Although component analysis of dental porcelain may be an effective means of assisting dental identification, a more rapid and non-destructive analysis for detecting the elements is required. The energy dispersive X-ray fluorescence (EDXRF) spectrometer was used for a pilot study of identification of porcelain composition.

  10. Dental self-care among dentate adults: contrasting problem-oriented dental attenders and regular dental attenders.

    PubMed

    Gilbert, G H; Stoller, E P; Duncan, R P; Earls, J L; Campbell, A M

    2000-01-01

    Self-care behaviors are common and can act as substitutes for or supplements to formal health care services. We tested the hypothesis that problem-oriented dental attenders (POAs) report more dental self-care behaviors than do regular dental attenders (RAs), presumably as a substitute for professional care. The Florida Dental Care Study is a longitudinal cohort study of changes in oral health, in which we measured dental self-care behaviors related to three common dental problems: toothache pain, bleeding gums, and tooth loss. Despite using less dental care, POAs were less likely to report "conventional" methods as means to prevent the three dental problems; however, they were more likely to report that homemade remedies, topical medications, or mouthwashes were ways to prevent or treat these problems. POAs were also more likely to believe that "nothing can be done" to prevent these problems. Additionally, POAs had more negative dental attitudes, used less dental care during follow-up, had more dental disease, were the only persons who extracted at least one of their own teeth, and were more likely to use tobacco. With the exception of dental self-extractions, no single self-care belief or behavior distinguished POAs from RAs, nor were POAs likely to have different explanations for dental problems. Instead, the pattern was one of modest differences on a number of items. Although POAs use less dental care, they do not compensate by employing more "conventional" dental self-care behaviors, but report being more likely to employ "unconventional" behaviors. They also are more likely to believe that nothing can be done to prevent dental problems.

  11. Dental Students' Perceptions of Learning Value in PBL Groups with Medical and Dental Students Together versus Dental Students Alone.

    PubMed

    Amin, Maryam; Zulla, Rosslynn; Gaudet-Amigo, Gisele; Patterson, Steven; Murphy, Natalie; Ross, Shelley

    2017-01-01

    At a dental school in Canada, problem-based learning (PBL) sessions were restructured from an integrated dental-medical model to a separate dental model, resulting in three groups of students available for study: those who had participated in the two-year dental and medical combined, the one-year dental and medical combined, the one-year dental alone, and the two-year dental alone. The aim of this qualitative study was to examine the extent to which the PBL structure affected the dental students' perceptions of the learning value of PBL in the different models. A total of 34 first-, second-, and third-year dental students participated in six focus groups in May and June 2011 (34% of students in those total classes). Semistructured questions explored their experiences in the different PBL structures. The interviews were recorded and transcribed verbatim, and thematic analysis was employed. The results showed positive and negative perceptions for both the combined dental and medical settings and the settings with dental students alone. For students in the combined PBL groups, positive perceptions included gaining information from medical peers, motivation to learn, and interdisciplinary collaborations. The negative perceptions mainly related to irrelevant content, dominating medical students, and ineffective preceptors. Members of the separate dental groups were more positive about the content and felt a sense of belonging. They appreciated the dental preceptors but were concerned about the inadequacy of their medical knowledge. Overall, the dental students valued the combined PBL experience and appreciated the opportunity to learn with their medical colleagues. Close attention, however, must be paid to PBL content and the preceptor's role to optimize dental students' experience in combined medical and dental groups.

  12. Saliva and dental plaque.

    PubMed

    Rudney, J D

    2000-12-01

    Dental plaque is being redefined as oral biofilm. Diverse overlapping microbial consortia are present on all oral tissues. Biofilms are structured, displaying features like channels and projections. Constituent species switch back and forth between sessile and planktonic phases. Saliva is the medium for planktonic suspension. Several major functions can be defined for saliva in relation to oral biofilm. It serves as a medium for transporting planktonic bacteria within and between mouths. Bacteria in transit may be vulnerable to negative selection. Salivary agglutinins may prevent reattachment to surfaces. Killing by antimicrobial proteins may lead to attachment of dead cells. Salivary proteins form conditioning films on all oral surfaces. This contributes to positive selection for microbial adherence. Saliva carries chemical messengers which allow live adherent cells to sense a critical density of conspecifics. Growth begins, and thick biofilms may become resistant to antimicrobial substances. Salivary macromolecules may be catabolized, but salivary flow also may clear dietary substrates. Salivary proteins act in ways that benefit both host and microbe. All have multiple functions, and many do the same job. They form heterotypic complexes, which may exist in large micelle-like structures. These issues make it useful to compare subjects whose saliva functions differently. We have developed a simultaneous assay for aggregation, killing, live adherence, and dead adherence of oral species. Screening of 149 subjects has defined high killing/low adherence, low killing/high adherence, high killing/high adherence, and low killing/low adherence groups. These will be evaluated for differences in their flora.

  13. Medicaid dental coverage alone may not lower rates of dental emergency department visits.

    PubMed

    Fingar, Kathryn R; Smith, Mark W; Davies, Sheryl; McDonald, Kathryn M; Stocks, Carol; Raven, Maria C

    2015-08-01

    Medicaid was expanded to millions of individuals under the Affordable Care Act, but many states do not provide dental coverage for adults under their Medicaid programs. In the absence of dental coverage, patients may resort to costly emergency department (ED) visits for dental conditions. Medicaid coverage of dental benefits could help ease the burden on the ED, but ED use for dental conditions might remain a problem in areas with a scarcity of dentists. We examined county-level rates of ED visits for nontraumatic dental conditions in twenty-nine states in 2010 in relation to dental provider density and Medicaid coverage of nonemergency dental services. Higher density of dental providers was associated with lower rates of dental ED visits by patients with Medicaid in rural counties but not in urban counties, where most dental ED visits occurred. County-level Medicaid-funded dental ED visit rates were lower in states where Medicaid covered nonemergency dental services than in other states, although this difference was not significant after other factors were adjusted for. Providing dental coverage alone might not reduce Medicaid-funded dental ED visits if patients do not have access to dental providers.

  14. Differential diagnosis of dental fluorosis made by undergraduate dental students

    PubMed Central

    Rigo, Lilian; Lodi, Leodinei; Garbin, Raíssa Rigo

    2015-01-01

    ABSTRACT Objective To check knowledge of undergraduate dental students to make diagnosis of dental fluorosis with varying degrees of severity and choose its appropriate treatment. Methods Data were collected using a semi-structured questionnaire addressing knowledge of undergraduates based on ten images of mouths presenting enamel changes. Results Only three images were correctly diagnosed by most undergraduates; the major difficulty was in establishing dental fluorosis severity degree. Conclusion Despite much information about fluorosis conveyed during the Dentistry training, as defined in the course syllabus, a significant part of the students was not able to differentiate it from other lesions; they did not demonstrate expertise as to defining severity of fluorosis and indications for treatment, and could not make the correct diagnosis of enamel surface changes. PMID:26761552

  15. Curriculum Guidelines for Clinical Dental Hygiene.

    ERIC Educational Resources Information Center

    Journal of Dental Education, 1985

    1985-01-01

    The American Association of Dental Schools curriculum guidelines for clinical dental hygiene include definitions, notes on the interrelationship of courses, an overview of course objectives, and suggested primary educational goals, prerequisites, core content, specific objectives, sequencing, faculty, and facilities. (MSE)

  16. American Academy of Dental Sleep Medicine

    MedlinePlus

    ... Dentist Applications Now Accepted Join Us in Boston! Membership Join the American Academy of Dental Sleep Medicine ... and more. View Member Benefits... Join Now Renew Membership Diplomate Certification The American Board of Dental Sleep ...

  17. Curricular Guidelines for Teaching Dental Anatomy.

    ERIC Educational Resources Information Center

    Okeson, Jeffrey; Buckman, James

    1981-01-01

    Guidelines developed by the Section on Dental Anatomy and Occlusion of the American Association of Dental Schools for use by individual educational institutions as curriculum development aids are provided. (MLW)

  18. Dental Health Education: Rhetoric or Reality?

    ERIC Educational Resources Information Center

    Taub, Alyson

    1982-01-01

    Suggestions for facilitating dental health education programs in public schools include: (1) determining who will be responsible for dental health education; (2) involving parents; (3) using community health resources; and (4) assessing the results of programs. (JN)

  19. National Institute of Dental and Craniofacial Research

    MedlinePlus

    ... Internships for... High School and College Students Recent College Graduates Dental and Medical Students See All Careers & Training Careers Job Openings Careers in Dental Research Loan Repayment Programs NIH Loan Repayment Programs A–Z ...

  20. Financing dental care: trends in public and private expenditures for dental services.

    PubMed

    Bailit, Howard; Beazoglou, Tryfon

    2008-04-01

    This article examines the financing of dental care in the United States. The major issues addressed include the amount and sources of funds, the reasons for increased dental care expenditures, the comparison of dental care with other medical care expenditures, the policy implications of current trends, and some cautious predictions about the financing of dental care in the next 10 to 20 years. The supply of dental services is expected to increase substantially in the next 10 to 20 years with more dental school graduates, a new midlevel practitioner, and greater use of allied dental health personnel. Whether the supply of services will grow faster than the demand for care is unknown.

  1. Aesthetic management of dental fluorosis.

    PubMed

    Khandelwal, Vishal; Nayak, Ullal Anand; Nayak, Prathibha Anand; Ninawe, Nupur

    2013-05-22

    Significant numbers of patients visiting the paediatric dental clinics have aesthetically objectionable brown stains and desire treatment for them. Intrinsic tooth discolouration can be a significant aesthetic, and in some instances, functional, problem. Dental fluorosis, tetracycline staining, localised and chronological hypoplasia, and both amelogenesis and dentinogenesis imperfecta can all produce a cosmetically unsatisfactory dentition. The aetiology of intrinsic discolouration of enamel may sometimes be deduced from the patient's history, and one factor long associated with the problem has been a high level of fluoride intake. Optimal use of topical fluorides leads to a decrease in the caries prevalence but may show an increase in the prevalence of fluorosis staining because of metabolic alterations in the ameloblasts, causing a defective matrix formation and improper calcification. A 12-year-old male patient was screened at the dental clinic for routine dental care. He wanted us to remove and/or minimise the noticeable brown/yellow staining of his teeth. He requested the least invasive and most cost-effective treatment to change his smile. Various treatment modalities are present for the treatment of fluorosis stains. This report discusses the microabrasion technique in the patient having dental fluorosis.

  2. Dental surgery in ancient Egypt.

    PubMed

    Blomstedt, Patric

    2013-01-01

    Many different surgical procedures have over the years been attributed to the ancient Egyptians. This is also true regarding the field of dental surgery. The existence of dentists in ancient Egypt is documented and several recipes exist concerning dental conditions. However, no indications of dental surgery are found in the medical papyri or in the visual arts. Regarding the osteological material/mummies, the possible indications of dental surgery are few and weak. There is not a single example of a clear tooth extraction, nor of a filling or of an artificial tooth. The suggested examples of evacuation of apical abscesses can be more readily explained as outflow sinuses. Regarding the suggested bridges, these are constituted of one find likely dating to the Old Kingdom, and one possibly, but perhaps more likely, dating to the Ptolemaic era. Both seem to be too weak to have served any possible practical purpose in a living patient, and the most likely explanation would be to consider them as a restoration performed during the mummification process. Thus, while a form of dentistry did certainly exist in ancient Egypt, there is today no evidence of dental surgery.

  3. Aesthetic management of dental fluorosis

    PubMed Central

    Khandelwal, Vishal; Nayak, Ullal Anand; Nayak, Prathibha Anand; Ninawe, Nupur

    2013-01-01

    Significant numbers of patients visiting the paediatric dental clinics have aesthetically objectionable brown stains and desire treatment for them. Intrinsic tooth discolouration can be a significant aesthetic, and in some instances, functional, problem. Dental fluorosis, tetracycline staining, localised and chronological hypoplasia, and both amelogenesis and dentinogenesis imperfecta can all produce a cosmetically unsatisfactory dentition. The aetiology of intrinsic discolouration of enamel may sometimes be deduced from the patient's history, and one factor long associated with the problem has been a high level of fluoride intake. Optimal use of topical fluorides leads to a decrease in the caries prevalence but may show an increase in the prevalence of fluorosis staining because of metabolic alterations in the ameloblasts, causing a defective matrix formation and improper calcification. A 12-year-old male patient was screened at the dental clinic for routine dental care. He wanted us to remove and/or minimise the noticeable brown/yellow staining of his teeth. He requested the least invasive and most cost-effective treatment to change his smile. Various treatment modalities are present for the treatment of fluorosis stains. This report discusses the microabrasion technique in the patient having dental fluorosis. PMID:23704468

  4. Thalassemias and their dental implications.

    PubMed

    Cutando Soriano, Antonio; Gil Montoya, José Antonio; López-González Garrido, Juan de Dios

    2002-01-01

    Thalassemias constitute a form of anemia that pose clear problems in relation to dental treatment. Dental professionals must be aware of the treatment adaptations required in patients with severe forms of beta-thalassemia. Until medical research is able to afford a definitive solution to these diseases (thereby greatly simplifying the dental management of such patients), effort will continue to center on the improvement of available therapeutic modalities, with the aim of obtaining effective and inexpensive oral chelators and drugs that either individually or in combination allow increases in fetal hemoglobin levels. Undoubtedly, the use of such measures together with serial blood transfusions has made it possible for an ever increasing number of patients with beta-thalassemia to reach adult age, where the provision of integral rather than merely palliative dental treatment must be seriously considered. At present, the clinical orofacial manifestations caused by the erythroid mass expanding the facial bones - resulting in dental malocclusions and protrusions tend to be less intense as a result of early medical treatment. In the future, gene therapy may be expected to allow a normal facial appearance thanks to complete healing of the patient.

  5. Sedation in Japanese dental schools.

    PubMed Central

    Morse, Zac; Sano, Kimito; Fujii, Kazuyuki; Kanri, Tomio

    2004-01-01

    There is very little information about the practice of sedation in Japan. Despite the remarkable advances in dentistry, fear and anxiety continue to be significant deterrents for seeking dental services. Most dental procedures can fortunately be undertaken with the aid of sedation. A comprehensive survey of all the dental schools in Japan was carried out to determine what sedation practices were used in Japan. All 29 dental schools in Japan possessed a dedicated department of anesthesiology at the time of this survey. The survey attempted to determine the specific sedation methods (techniques, routes of administration, and agents used in sedation) as well as practices (monitoring, fasting, location, education, and fees involved in sedation). The results indicate that there was a broad range in sedation practices. The Japanese Dental Society of Anesthesiology may wish to examine the findings of this study and may wish to formulate guidelines appropriate for the practice of sedation in Japan. Others may also wish to compare their own practices with those of Japan. PMID:15497299

  6. [Dental health: relationship between dental caries and food consumption].

    PubMed

    González Sanz, Angel Miguel; González Nieto, Blanca Aurora; González Nieto, Esther

    2013-07-01

    Although the reduction and prevalence of dental caries in many countries has been largely associated with the use of fluorine and improving dental hygiene, eating habits also play a role in the development of caries. Fermentable carbohydrates characteristics of the food, rate of consumption, food protectors, the quality and quantity of saliva indices that determine the remineralization of teeth are factors to be considered. All these elements are analyzed through the sociodemographic, behavioral, physical and biological environment directly or indirectly with diet and caries.

  7. Diagnosis and management of dental wear.

    PubMed

    Harpenau, Lisa A; Noble, Warden H; Kao, Richard T

    2011-04-01

    Dental wear is loss of tooth structure resulting from erosion, attrition, abrasion, and, possibly, abfraction. Clinical/experimental data suggest no single damaging mechanism but rather simultaneous interaction of these destructive processes. The most important interaction is abrasion/attrition potentiated by dental erosion. Awareness of this pathosis is not well-appreciated by the public and dental professionals because the signs may be subtle. This article focuses on the recognition, diagnosis, and management of dental wear.

  8. Patient Satisfaction in Military Dental Treatment Facilities

    DTIC Science & Technology

    2006-03-07

    related to technical expertise, Crall and Morris (1988) and Abrams, Ayers and Vogt-Petterson (1986) found that patient satisfaction was not well ...mission of the Army Dental Care Dental Patient Satisfaction 93 System. Dental emergencies in deployed military populations have been well documented...that choice. The ratings of the beliefs about the care received were high as well . Mean scores on the seven belief questions Dental Patient Satisfaction

  9. Developing Teaching Expertise in Dental Education

    ERIC Educational Resources Information Center

    Lyon, Lucinda J.

    2009-01-01

    This exploratory study was designed to develop a baseline model of expertise in dental education utilizing the Dreyfus and Dreyfus continuum of skill acquisition. The goal was the development of a baseline model of expertise, which will contribute to the body of knowledge about dental faculty skill acquisition and may enable dental schools to…

  10. Dental Assisting Course. Bilingual Vocational Instructional Materials.

    ERIC Educational Resources Information Center

    Lopez-Cox, Guadalupe

    This course in dental assisting, one of a series of bilingual English-Spanish vocational education courses, is designed to prepare the student to assist the dentist at the chairside in the dental operatory, to perform reception and clerical functions, and to carry out selected dental laboratory work. The course covers an introduction to the…

  11. First-Aid Algorithms in Dental Avulsion

    ERIC Educational Resources Information Center

    Baginska, Joanna; Wilczynska-Borawska, Magdalena

    2012-01-01

    Almost one fourth of traumatic dental injuries occur at schools or in their surroundings. Prevalence of tooth avulsion varies from 0.5% to 16% of all cases of dental trauma. Children with dental avulsion may seek help from school nurses so they should be able to provide first-aid treatment. However, many studies showed that the general level of…

  12. A Cognitive Task Analysis for Dental Hygiene.

    ERIC Educational Resources Information Center

    Cameron, Cheryl A.; Beemsterboer, Phyllis L.; Johnson, Lynn A.; Mislevy, Robert J.; Steinberg, Linda S.; Breyer, F. Jay

    2000-01-01

    As part of the development of a scoring algorithm for a simulation-based dental hygiene initial licensure examination, this effort conducted a task analysis of the dental hygiene domain. Broad classes of behaviors that distinguish along the dental hygiene expert-novice continuum were identified and applied to the design of nine paper-based cases…

  13. Utilization of dental care: An Indian outlook.

    PubMed

    Gambhir, Ramandeep Singh; Brar, Prabhleen; Singh, Gurminder; Sofat, Anjali; Kakar, Heena

    2013-07-01

    Oral health has a significant impact on the quality of life, appearance, and self-esteem of the people. Preventive dental visits help in the early detection and treatment of oral diseases. Dental care utilization can be defined as the percentage of the population who access dental services over a specified period of time. There are reports that dental patients only visit the dentist when in pain and never bother to return for follow-up in most cases. To improve oral health outcomes an adequate knowledge of the way the individuals use health services and the factors predictive of this behavior is essential. The interest in developing models explaining the utilization of dental services has increased; issues like dental anxiety, price, income, the distance a person had to travel to get care, and preference for preservation of teeth are treated as barriers in regular dental care. Published materials which pertain to the use of dental services by Indian population have been reviewed and analyzed in depth in the present study. Dental surgeons and dental health workers have to play an adequate role in facilitating public enlightenment that people may appreciate the need for regular dental care and make adequate and proper use of the available dental care facilities.

  14. 78 FR 32126 - VA Dental Insurance Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-29

    ... AFFAIRS 38 CFR Part 17 RIN 2900-AN99 VA Dental Insurance Program AGENCY: Department of Veterans Affairs... rules and procedures for the VA Dental Insurance Program (VADIP), a pilot program that offers premium-based dental insurance to enrolled veterans and certain survivors and dependents of veterans. Under...

  15. Dental disease in children with chronic illness

    PubMed Central

    Foster, H; Fitzgerald, J

    2005-01-01

    We focus on the role of the general paediatrician in promoting the importance of good dental health for all children and in particular those children "at risk". We present preventive measures, evidence based where available, that may improve dental care and promote the role of paediatric dental services in the multidisciplinary management of chronic disease. PMID:15970611

  16. Supply and Demand: Lessons from Dental Medicine?

    ERIC Educational Resources Information Center

    Cohen, D. Walter

    1988-01-01

    Four major factors responsible for trends in applicants to dental school are identified: cost, competition, demographics, and the practicing dentist. The initiation of the Pew National Dental Education Program at the University of Pennsylvania School of Dental Medicine is described. (MLW)

  17. Dental Education at the Crossroads--Summary.

    ERIC Educational Resources Information Center

    Journal of Dental Education, 1995

    1995-01-01

    An Institute of Medicine study concerning dental education's future is summarized. Eight principles guiding the study are outlined, and findings/recommendations in each area (oral health status, dental education's mission, focus on health outcomes, research role, patient care, dental school's role in the university, accreditation, dental…

  18. Issues in Dental Curriculum Development and Change.

    ERIC Educational Resources Information Center

    Tedesco, Lisa A.

    1995-01-01

    An extensive discussion of curriculum reform in dental education looks at the history of dental curriculum since 1926, reviewing major reports and studies and examining systematic attempts to alter the curriculum, both structurally and philosophically. The paper was prepared as background for an Institute of Medicine study of dental education's…

  19. [Syncope in the dental environment].

    PubMed

    Findler, M; Elad, S; Garfunkel, A; Zusman, S P; Malamed, S F; Galili, D; Kaufman, E

    2002-01-01

    Syncope or Fainting is, by far, the most common emergency situation in the dental practice. Syncope is defined as an abrupt, transient, short term loss of consciousness and postural tone, followed by spontaneous and complete recovery. The pathophysiology of syncope consists of a sudden cessation or decrease in cerebral perfusion. Differential diagnosis of these medical conditions is of paramount importance in uncovering unrecognized systemic diseases. The dental team plays an important role in the process of establishing the correct diagnosis by its ability to recognize and document all the clinical symptoms and signs evident at the time of fainting. The dental surgeon is expected to be familiar with the various etiologies of syncope and should be able to differentiate between them. This article provides the essentials of the diagnostic procedure and an approach to the evaluation of the unconscious patient.

  20. Dental issues in Rett syndrome.

    PubMed

    Janas, Anna; Osica, Piotr

    2015-01-01

    The advancements in science and technology allowed saving the lives of children, who had no chance of survival before. Hence the problem of so called rare diseases, usually genetically determined. It is a new challenge for both the physicians and the health services. These children require a coordinated multi specialist oriented health care, which includes also dentists. This situation is reflected by the case of an 18 years old girl with Rett Syndrome, described by us. In this patient despite numerous visits to various dental practices, no decision of a radical surgical extraction of the tooth has been conducted. In our Department the extraction of teeth 22, 16 and 14 has been performed, as a part of 1 day surgery procedures, thus eliminating the dental infections and pain. Conclusion: Elaboration and introduction into praxis principles of dental care in children and young adults with rare diseases are needed.

  1. Biofilm and dental unit waterlines.

    PubMed

    Szymanska, Jolanta

    2003-01-01

    Aquatic biofilms, which are well-organized communities of microorganisms, are widespread in nature. They constitute a major problem in many environmental, industrial and medical settings. The use of advanced techniques has revealed biofilm structure, formation and ecology. Special attention was given to the build-up of biofilm in dental unit waterlines (DUWLs), which are small-bore flexible plastic tubing to bring water to different handpieces. They are coated with well-established biofilms. Active biofilm is a source of microbial contamination of DUWLs water. The safety of dental treatment requires a good quality of the water used. The knowledge of nature, formation and the ways to eliminate the biofilm is the first step towards reducing health risk, both for patients and dental personnel. The article reviews these issues.

  2. Nutrition and dental caries.

    PubMed

    Mobley, Connie C

    2003-04-01

    Promotion of sound dietary practices is an essential component of caries management, along with fluoride exposure and oral hygiene practices. Scientific discoveries have lead to better understanding of the caries process, the ever-expanding food supply, and the interaction between the two. Fermentable carbohydrates interact dynamically with oral bacteria and saliva, and these foods will continue to be a major part of a healthful diet. Dental health professionals can serve their patients and the public by providing comprehensive oral health care and by promoting lifestyle behaviors to improve oral and general health within the time constraints of their practice. Dietary advice given should not contradict general health principles when providing practical guidance to reduce caries risk. The following principles should guide messages: * Encourage balanced diets based on moderation and variety as depicted by the Food Guide Pyramid and the Dietary Guidelines for Americans to provide a sound approach. Avoid references to "bad" foods and focus on "good" diets that include a variety of foods. * Give examples of how combining and sequencing foods can enhance mastication, saliva production, and oral clearance at each eating occasion. Combining dairy foods with sugary foods, raw foods with cooked, and protein-rich foods with acidogenic foods are all good examples. Suggest that eating and drinking be followed by cariostatic foods such as xylitol chewing gum. * Drink water to satisfy thirst and hydration needs as often as possible. Restrict consumption of sweetened beverages to meal and snack times when they can be combined with other cariostatic foods. * When a patient reports excessive dietary intake of a fermentable carbohydrate to the point of displacing other important foods in the diet, identify alternatives that will help the patient maintain or achieve a healthy body weight, oral health status, and a nutrient-dense intake.

  3. [Autism-friendly dental care].

    PubMed

    Kind, L S; van Gemert-Schriks, M C M; Elhorst, J H

    2016-02-01

    Autism Spectrum Disorder (ASD) occurs in approximately 1% of the Dutch population. Among the group of patients with this disorder, there is a substantial diversity regarding skills, intelligence and treatability. However, there are also common characteristics; people with ASD often have difficulty with social interaction, communication, and exhibit typical patterns of behaviour. Therefore, problems may arise in the various areas of development, such as language development and responding to sensory stimuli. Dental practitioners will also be confronted with individuals with ASD. Care can be significantly improved, considering that negative experiences and dental anxiety are widespread at this time.

  4. Cerebral Palsy: A Dental Update

    PubMed Central

    Sehrawat, Nidhi; Bansal, Kalpana; Chopra, Radhika

    2014-01-01

    ABSTRACT Special and medically compromised patients present a unique population that challenges the dentist’s skill and knowledge. Providing oral care to people with cerebral palsy (CP) requires adaptation of the skills we use everyday. In fact, most people with mild or moderate forms of CP can be treated successfully in the general practice setting. This article is to review various dental considerations and management of a CP patient. How to cite this article: Sehrawat N, Marwaha M, Bansal K, Chopra R. Cerebral Palsy: A Dental Update. Int J Clin Pediatr Dent 2014;7(2):109-118. PMID:25356010

  5. DENTAL HEALTH STATUS AND DENTAL HEALTH SERVICES FOR RURAL YOUTH.

    ERIC Educational Resources Information Center

    DONNELLY, CHARLES J.

    ALTHOUGH DENTAL PROBLEMS ARE COMMON IN BOTH RURAL AND URBAN AREAS, RURAL CHILDREN SEEM TO HAVE MORE DIFFICULTIES. THE REASONS FOR THIS APPEAR TO BE THAT THERE ARE FEWER DENTISTS PER CAPITA IN RURAL AREAS, AND THAT THE RURAL CHILD IS USUALLY EXPOSED TO A WATER SYSTEM LACKING FLUORIDATION, WHICH IS THE MOST EFFECTIVE WAY OF ADMINISTERING FLUORIDES.…

  6. Who is dentally anxious? Concordance between measures of dental anxiety.

    PubMed

    Locker, D; Shapiro, D; Liddell, A

    1996-10-01

    Studies of the prevalence of dental anxiety in general population samples have produced estimates which range from a low of 2.6% to a high of 20.4%. It is not clear whether these reflect real differences among populations or whether they are the result of the use of different measures and different cut-off points. We undertook a large scale mail survey of dental anxiety in a random sample of the adult population living in Metropolitan Toronto designed to assess the performance of and agreement between three measures. These were Corah's DAS, the single item used by Milgrom and colleagues in Seattle and the ten-point fear scale used by Gatchel. These measures and their published cut-off points produced prevalence estimates of 10.9%, 23.4% and 8.2% respectively. While there was a significant association between scores on pairs of measures the agreement between them was far from perfect. Kappa values ranged from 0.37 to 0.56, indicating only fair to moderate agreement beyond chance. There was evidence to indicate that the dentally anxious subjects identified by each measure differed according to certain behavioural and other characteristics. The results of the study suggest the need to revisit the issue of measurement in studies of dental anxiety.

  7. The effect of openings on the long term deflection and flexural capacity of laminated veneer lumber (LVL)

    NASA Astrophysics Data System (ADS)

    Mancini, Matthew L.

    In most residential construction projects, laminated veneer lumber (LVL) beams are used to help support floor systems, and span doorways or garage door openings, amongst other applications. Because of its diverse application, it is not uncommon that openings are drilled through LVL beams to allow for the passage of utilities. This research evaluates the effects these openings have on long term deflection and flexural capacity, and looks to determine if current provisions for openings need to be amended. Two separate tests were conducted to analyze these behaviors. A long term flexural test was completed to determine the relative creep behavior, and an ultimate load test was conducted to determine the failure load under bending. A total of 26 beams (13 total samples) were tested in the long term test, which included beams with 5 different hole patterns loaded to either 50% or 75% of the allowable load set by the manufacturer. Each beam was loaded for over a year, and its midspan deflection and moisture content was monitored periodically. The environmental conditions such as relative humidity and temperature were also carefully monitored to determine if there was a correlation between relative humidity and long term deflection. Seven of the samples from the long term test were used in the ultimate load test, which included a control sample that was loaded to 60% of the predicted ultimate load so that it could continue being used as a control for the long term test. During the ultimate load test the midpsan and quarterspan deflections were recorded using LVDTs, and the total load was monitored via 4 load cells evenly spaced along the sample. This study found that 2" diameter openings placed in the middle third of the beam length and depth do not significantly affect the long term deflection or flexural capacity of LVL beams. However, as the 2" diameter openings are shifted away from the beam centroid, there is an evident decrease in overall performance in terms of

  8. Quality considerations in dental education in India.

    PubMed

    Virdi, Mandeep S

    2012-03-01

    Undergraduate dental education programs have grown tremendously in India over the last five to six decades, mainly in the private sector, putting significant pressure on resources including faculty. This has raised concerns about the quality of dental education in the country. This article examines the concept of quality as applicable to higher education. It provides a roadmap for application of quality concepts, including steps for improving the effectiveness of teaching and applying Total Quality Management to dental education. It also makes suggestions for college-level and structural-level changes to meet the requirement of improved quality, which includes the addition of dental education as a subject in postgraduate dental programs.

  9. Dental stem cells and their sources.

    PubMed

    Sedgley, Christine M; Botero, Tatiana M

    2012-07-01

    The search for more accessible mesenchymal stem cells than those found in bone marrow has propelled interest in dental tissues. Human dental stem/progenitor cells (collectively termed dental stem cells [DSCs]) that have been isolated and characterized include dental pulp stem cells, stem cells from exfoliated deciduous teeth, stem cells from apical papilla, periodontal ligament stem cells, and dental follicle progenitor cells. Common characteristics of these cell populations are the capacity for self-renewal and the ability to differentiate into multiple lineages. In vitro and animal studies have shown that DSCs can differentiate into osseous, odontogenic, adipose, endothelial, and neural-like tissues.

  10. Prevention of dental disease versus surgical treatment.

    PubMed

    Larson, Thomas D

    2014-01-01

    The members of the Minnesota legislature have debated methods by which access to dental care and treatment of dental disease can be improved at a cost lower than that of present delivery systems. This review sheds light on some significant aspects of what the dental profession has learned over the last century that has proven significantly beneficial to the overall health of the American populace. Recommendations are made in the use of cost-effective dental public health interventions that could be used to provide better access and improved dental health at lower cost.

  11. Health maintenance facility: Dental equipment requirements

    NASA Technical Reports Server (NTRS)

    Young, John; Gosbee, John; Billica, Roger

    1991-01-01

    The objectives were to test the effectiveness of the Health Maintenance Facility (HMF) dental suction/particle containment system, which controls fluids and debris generated during simulated dental treatment, in microgravity; to test the effectiveness of fiber optic intraoral lighting systems in microgravity, while simulating dental treatment; and to evaluate the operation and function of off-the-shelf dental handheld instruments, namely a portable dental hand drill and temporary filling material, in microgravity. A description of test procedures, including test set-up, flight equipment, and the data acquisition system, is given.

  12. Ketoprofen Dental Pain Study.

    PubMed

    Levin, L M; Cooper, S A; Betts, N J; Wedell, D; Hermann, D G; Lamp, C; Secreto, S A; Hersh, E V

    1997-01-01

    Ketoprofen is a nonsteroidal antiinflammatory drug, recently approved as an over-the-counter (OTC) analgesic at a 12.5 mg dosage strength. This is the first published study which explores the analgesic efficacy and safety of ketoprofen 12.5 mg in patients experiencing pain following the removal of impacted third molars. This study was single-dose, double-blind and randomized utilizing a 6-hour in-patient evaluation period. Patients ingested a single dose of ketoprofen 12.5 mg (n = 30), ketoprofen 37.5 mg (n = 32) or placebo (n = 15) when their post-surgical pain reached at least a moderate intensity on a 5-point categorical (CAT) scale and greater than 50 mm on a 100 mm visual analog scale (VAS). Measures of pain intensity and relief were gathered every 20 minutes for the first 2 hours, and then hourly from hours 3 through 6. Adverse drug reactions were also recorded as they occurred. Both dosages of ketoprofen were significantly more efficacious than placebo (two way ANOVAs, p < 0.05). For pain intensity difference (PID) and pain relief, the 12.5 mg dose exhibited statistical superiority from hours 1 through 3, while the 37.5 mg dose exhibited statistical superiority from 40 minutes through 4 hours. Ketoprofen 37.5 mg was significantly more efficacious than the 12.5 mg dose only at 40 minutes for PID(VAS) and relief, and at 60 minutes for PID(VAS). Both ketoprofen dosages displayed significantly greater 3-hr, 4-hr and 6-hr summary analgesic measures (SPID(VAS), SPID(CAT), TOTPAR) than placebo, with the exception of the 6-hr SPID(CAT) measure for ketoprofen 12.5 mg. No serious side effects were observed in this study. We conclude that ketoprofen in a dose range of 12.5 mg to 37.5 mg is a safe and effective analgesic for the relief of post-operative dental pain.

  13. Radiographic signs and diagnosis of dental disease.

    PubMed

    Bellows, J

    1993-08-01

    Dental radiographs are critical for the complete assessment and treatment of dental diseases. Dental radiography is commonly used to evaluate congenital dental defects, periodontal disease, orthodontic manipulations, oral tumors, endodontic treatments, oral trauma, and any situation where an abnormality is suspected. Although standard radiographic equipment and film can be used to produce dental radiographs, dental X-ray equipment and film provide superior quality images and greater convenience of animal patient positioning. An understanding of normal dental radiographic anatomy is important when interpreting dental radiographs. Stage III periodontitis is the earliest stage of periodontal disease at which radiographic abnormalities become apparent. Bone loss associated with periodontal disease can be classified as either horizontal or vertical. Periapical radiolucencies can represent granulomas, cysts, or abscesses, whereas periapical radiodensities may represent sclerotic bone or condensing osteitis. Lytic lesions of the bone of the jaw often represent oral neoplasms. Neoplasms also can displace or disrupt teeth in the dental arch. Resorptive lesions can be external or internal and appear as radiolucent areas involving the external surface of the root or the pulp cavity, respectively. Feline dental resorptive lesions, also known as odontoclastic resorptions, are a specific form of dental resorptive lesions unique to cats.

  14. Is there an association between the presence of dental fluorosis and dental trauma amongst school children?

    PubMed

    Oliveira, Lorenna Fonseca Braga de; Souza, João Gabriel Silva; Mendes, Rafael Inácio Pompeu; Oliveira, Rodrigo Caldeira Nunes; Oliveira, Carolina de Castro; Lima, Carolina Veloso; Martins, Andréa Maria Eleutério de Barros Lima

    2016-03-01

    Our objective was to evaluate whether there is an association with the different levels of dental fluorosis and the presence of dental trauma amongst school children. A transversal study was conducted amongst school children from the age of 12. Dental examinations were conducted by 24 well trained and fully qualified dental surgeons. Data was collected from 36 randomly selected public schools amongst 89 schools in a municipality. The criteria used to diagnose dental fluorosis was based on the Dean's fluorosis Index and for diagnosing dental trauma we looked for clinical signs of crown fractures and dental avulsions. Multiple descriptive analysis, which was bivariate, was carried out. Amongst the 2,755 school children that took part in the study 1,089 (39.6%) were diagnosed with dental fluorosis and 106 (3.8%) had one tooth or more with dental trauma. We noted a high prevalence of dental fluorosis, independent of the level of severity, amongst individuals with one tooth or more who had dental trauma. This association was even more evident where there were severely high levels of fluorosis. We also noted that the presence of fluorosis was greater amongst those that actively paid more attention to discoloration on their teeth and who received treatment from a dental professional at their schools. Nevertheless dental fluorosis was associated with the presence of dental trauma, independent of its severity.

  15. Disparities in unmet dental need and dental care received by pregnant women in Maryland.

    PubMed

    Singhal, Astha; Chattopadhyay, Amit; Garcia, A Isabel; Adams, Amy B; Cheng, Diana

    2014-09-01

    To examine prenatal dental care needs, utilization and oral health counseling among Maryland women who delivered a live infant during 2001-2003 and identify the factors associated with having a dental visit and having an unmet dental need during pregnancy. Pregnancy Risk Assessment Monitoring System is an ongoing population based surveillance system that collects information of women's attitudes and experiences before, during, and shortly after pregnancy. Logistic regression was used to model dental visits and unmet dental need using predictor variables for Maryland 2001-2003 births. Less than half of all women reported having a dental visit and receiving oral health advice during pregnancy. Twenty-five percent of women reported a need for dental care, of which 33 % did not receive dental care despite their perceived need. Multivariate modeling revealed that racial minorities, women who were not married and those with annual income <$40,000 were least likely to have a dental visit. Women who were not married, had low annual income, were older than 40 years of age, had an unintended pregnancy and received prenatal care later than desired were most likely to have an unmet dental need during pregnancy. Despite reported needs and existing recommendations to include oral health as a component of prenatal care, less than half of pregnant women have a dental visit during their pregnancy. One-third of women with a dental problem did not have a dental visit highlighting the unmet need for dental care during pregnancy.

  16. Usefulness of Forensic Dental Symbols© and Dental Encoder© database in forensic odontology.

    PubMed

    Martínez-Chicón, Jesús; Valenzuela, Aurora

    2012-01-01

    A new universal graphic dental system, Forensic Dental Symbols(©), has been created to provide precision in the construction of dental records, improve standardization, and increase efficiency in dental identification procedures. Two hundred and thirty-four different graphic symbols representing the most frequent clinical status for each tooth were designed. Symbols can be then converted to a typographic font and then are ready to use in any computer. For the appropriate use, manipulation, and storage of dental information generated by the Forensic Dental Symbols(©), Dental Encoder(©) database has been created. The database contains all the information required by INTERPOL Disaster Victim Identification (DVI)-dental-forms. To explore the possibilities that Dental Encoder(©) offers, an antemortem dental database from a Spanish population of 3920 military personnel had been constructed. Data generated by Dental Encoder(©) were classified into sex and age groups. The program can perform an automatic search of the database for cases that match a selected clinical status presented in a single tooth or a combination of situations for several teeth. Moreover, Dental Encoder(©) allows information to be printed on INTERPOL DVI-dental-forms, or the inclusion of any completed form into any document, technical report, or identification of dental report.

  17. Dental extraction during dicumarol therapy.

    PubMed

    ASKEY, J M; CHERRY, C B

    1956-01-01

    Extraction of 14 teeth in six patients taking dicumarol caused no unusual bleeding. Discontinuance of dicumarol prior to dental extraction should not necessarily be a routine procedure; in certain persons with a demonstrated strong tendency to recurrent thrombosis, dicumarol should be continued, based on the decision that the danger of clotting without the drug is greater than the danger of bleeding with the drug.

  18. Genetic aspects of dental disorders.

    PubMed

    Townsend, G C; Aldred, M J; Bartold, P M

    1998-08-01

    This paper reviews past and present applications of quantitative and molecular genetics to dental disorders. Examples are given relating to craniofacial development (including malocclusion), oral supporting tissues (including periodontal diseases) and dental hard tissues (including defects of enamel and dentine as well as dental caries). Future developments and applications to clinical dentistry are discussed. Early investigations confirmed genetic bases to dental caries, periodontal diseases and malocclusion, but research findings have had little impact on clinical practice. The complex multifactorial aetiologies of these conditions, together with methodological problems, have limited progress until recently. Present studies are clarifying previously unrecognized genetic and phenotypic heterogeneities and attempting to unravel the complex interactions between genes and environment by applying new statistical modelling approaches to twin and family data. Linkage studies using highly polymorphic DNA markers are providing a means of locating candidate genes, including quantitative trait loci (QTL). In future, as knowledge increases; it should be possible to implement preventive strategies for those genetically-predisposed individuals who are identified to be at risk.

  19. Head Start Dental Health Curriculum.

    ERIC Educational Resources Information Center

    Administration for Children, Youth, and Families (DHHS), Washington, DC. Head Start Bureau.

    This curriculum for Head Start programs provides preschool learning experiences that teach about dental health. The majority of the curriculum guide is devoted to the following lesson plans: (1) "Introduction of 'Smiley the Super Pup'," an optional puppet character which may be used to review the concepts covered in each lesson; (2)…

  20. Preparing to Enter Dental School.

    ERIC Educational Resources Information Center

    Peterson, Shailer

    A guide for students who are seeking admission to dental school is presented. The comprehensive coverage includes basic facts about dentistry as well as specific requirements about the following areas: facts about health care providers, treating patients in dentistry, and nonpatient-oriented dentistry; historical landmarks in dentistry; the…

  1. 76 FR 14600 - Dental Conditions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-17

    ... least 180 days (or 90 days if a veteran of the Gulf War era), and The veteran's DD214 does not bear.... 2062 (Class II(b)). Who are former prisoners of war, as determined by the concerned military service... there is dental disability due to combat wounds or service trauma. To determine prisoner of war...

  2. Dental Hygienists Licensed in Washington.

    ERIC Educational Resources Information Center

    Washington State Dept. of Social and Health Services, Olympia. Health Manpower Project.

    Beginning with a statement on the profession of dental hygiene and the two types of professional preparation available in the field, the pilot study then presents a two-part summary of its findings and an explanation of the methodology employed. Part I of the main portion of the report concerns employment characteristics (status, age, residence,…

  3. Dentistry and Dental Hygiene Handbook.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Office of the Professions.

    This handbook, developed as a reference guide, contains the texts of laws, rules, and regulations of the New York State Education Department governing dentistry and dental hygiene practice in the state. It also describes licensure requirements and includes complete application forms and instructions for obtaining a license and first registration…

  4. 77 FR 4469 - Dental Conditions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-30

    ... economy, a sector of the economy, productivity, competition, jobs, the environment, public health or... dental treatment by VA's Veterans Health Administration (VHA), apply only when VHA requests information... greater health risks when combined with poor dentition. The preamble language is reflective of 38 CFR...

  5. Management Practices in Dental Schools.

    ERIC Educational Resources Information Center

    Journal of Dental Education, 2000

    2000-01-01

    Five articles on management practices in dental schools include: "Overview" (Robert W. Comer et al.); "Patient Support Services" (Betsy A. Hagan et al.); "Health and Financial Records" (Robert W. Comer et al.); "Support Services and Staff Responsibilities" (Wayne William Herman et al.) and "Implications and Future Challenges" (Robert W. Comer et…

  6. Dental Office Procedures. Student's Manual.

    ERIC Educational Resources Information Center

    Apfel, Maura; Weaver, Trudy Karlene

    This manual is part of a series dealing with skills and information needed by students in dental assisting. The individualized student materials are suitable for classroom, laboratory, or cooperative training programs. This student manual contains three units covering the following topics: ethics and jurisprudence; the appointment book; and…

  7. Health Instruction Packages: Dental Personnel.

    ERIC Educational Resources Information Center

    Hayes, Gary E.; And Others

    Text, illustrations, and exercises are utilized in this set of four learning modules designed to instruct non-professional dental personnel in selected job-related skills. The first module, by Gary E. Hayes, describes how to locate the hinge axis point of the jaw, place and secure a bitefork, and perform a facebow transfer. The second module,…

  8. Security in dental office computing.

    PubMed

    Alsobrook, Stephen C

    2002-01-01

    Dental office computers are increasingly used to store critical financial and clinical data. That data is subject to loss or alteration from a number of possible sources. Secure communications, security of the computer system from outside attacks, and data backup are discussed.

  9. Dental Assistant. Health Occupations Education.

    ERIC Educational Resources Information Center

    Hefner, Dollie

    This curriculum is comprised of 31 instructional units divided into eight subject areas: orientation (6 units), anatomy and physiology (6 units), dental histology (1 unit), microbiology and bacteriology (2 units), pharmacology (2 units), chairside assistance (9 units), roentgenology (2 units), and practice administration (3 units). Each…

  10. Dental plaque identification at home

    MedlinePlus

    ... about 30 seconds. Then rinse your mouth with water and examine your teeth. Any red-stained areas are plaque. A small dental mirror may help you check all areas. The second method uses a plaque light. ... your mouth gently with water. Examine your teeth and gums while shining an ...

  11. Prevention and dental health services.

    PubMed

    Widström, Eeva

    2004-01-01

    There has been, and still is a firm belief that regular use of dental services is beneficial for all. Thus governments in most European countries have shown some interest in training oral health care professionals, distributing the dental workforce and cost sharing. Constantly evolving treatment options and the introduction of new methods make dental clinicians feel uncertain as to which treatments are most useful, who would benefit from them, and which treatments will achieve cost-effective health gain. Although there is a considerable quantity of scientific literature showing that most available preventive measures are effective, and the number of sensible best-practice guidelines in prevention is growing, there are few studies on cost-efficiency of different methods and, secondly, the prevention and treatment guidelines are poorly known among general practitioners. In the eyes of the public, it is obvious that preventive methods practised by patients at home have been eclipsed by clinical procedures performed in dental clinics. Reliance on an increasingly individualistic approach to health care leads to the medicalisation of issues that are not originally health or medical problems. It is important to move general oral disease prevention back to the people who must integrate this in their daily routines. Prevention primarily based on healthy lifestyles, highlighted in the new public health strategy of the European Union (EU), is the key to future health policy.

  12. Dental Health for the Handicapped.

    ERIC Educational Resources Information Center

    Alabama Univ., Birmingham. Dental Advisory Committee.

    Guidelines to aid attendants to maintain good dental health among institutionalized mentally retarded persons are presented. Aspects considered include reasons for taking care of the mouth and means of adapting the oral hygiene program to each individual. Also described are oral hygiene programs now existing in group living settings and methods of…

  13. Medicaid Adult Dental Benefits Increase Use Of Dental Care, But Impact Of Expansion On Dental Services Use Was Mixed.

    PubMed

    Singhal, Astha; Damiano, Peter; Sabik, Lindsay

    2017-04-01

    Dental coverage for adult enrollees is an optional benefit under Medicaid. Thirty-one states and the District of Columbia have expanded eligibility for Medicaid under the Affordable Care Act. Millions of low-income adults have gained health care coverage and, in states offering dental benefits, oral health coverage as well. Using data for 2010 and 2014 from the Behavioral Risk Factor Surveillance System, we examined the impact of Medicaid adult dental coverage and eligibility expansions on low-income adults' use of dental care. We found that low-income adults in states that provided dental benefits beyond emergency-only coverage were more likely to have had a dental visit in the past year, compared to low-income adults in states without such benefits. Among states that provided dental benefits and expanded their Medicaid program, regression-based estimates suggest that childless adults had a significant increase (1.8 percentage points) in the likelihood of having had a dental visit, while parents had a significant decline (8.1 percentage points). One possible explanation for the disparity is that after expansion, newly enrolled childless adults might have exhausted the limited dental provider capacity that was available to parents before expansion. Additional policy-level efforts may be needed to expand the dental care delivery system's capacity.

  14. Dental students' familiarity with the medical management of dental patients at Brazilian dental schools.

    PubMed

    Araújo, Paula Caetano; Garbín, Cléa Adas Saliba; Moimaz, Suzely Adas Saliba; Saliba, Nemre Adas; Arcieri, Renato Moreira

    2013-05-01

    Drug therapy in dentistry is essential for patients' treatment and requires special care by dentists, so it must be part of a well-grounded education for predoctoral dental students. The aim of this study was to evaluate the knowledge of undergraduate students at dental schools in Brazil about the use of drugs in dental practice. The sample universe was comprised of all undergraduates enrolled in the last year of the dentistry course in three universities in 2010 (n=253). Inclusion criteria were students in their last year of enrollment and who agreed to participate in the research. The results were analyzed on Epi Info 3.5.1 software. Analyses were conducted with chi-square, Friedman, and Wilcoxon tests. Slightly more than half of the participants (51.9 percent) reported the ideal dose of anesthetic for a normal patient. However, their difficulties increased when asked about the relationship between the anesthetic and patients with systemic disease or those needing special care. Regarding drugs that usually cause allergic attack, only 29.2 percent and 36.6 percent, respectively, cited methyl methacrylate and latex. This study found that the knowledge of these undergraduates about the questions was deficient, so dental education should include more theoretical and clinical practice in recognizing the patient's medical needs.

  15. Sexual Advances by Patients in Dental Practice: Implications for the Dental and Dental Hygiene Curricula.

    ERIC Educational Resources Information Center

    Chiodo, Gary T.; And Others

    1992-01-01

    A survey of Oregon dentists (n=248) and dental hygienists (n=235) investigated frequency of patient-initiated sexual advances and methods of dealing with them. Up to 44 percent experienced 1 or more patient verbal advances, and 23 percent experienced physical advances during a 5-year period. Inclusion of related issues in professional curricula is…

  16. 21 CFR 872.4130 - Intraoral dental drill.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Intraoral dental drill. 872.4130 Section 872.4130...) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4130 Intraoral dental drill. (a) Identification. An intraoral dental drill is a rotary device intended to be attached to a dental handpiece to drill holes...

  17. 21 CFR 872.4130 - Intraoral dental drill.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Intraoral dental drill. 872.4130 Section 872.4130...) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4130 Intraoral dental drill. (a) Identification. An intraoral dental drill is a rotary device intended to be attached to a dental handpiece to drill holes...

  18. 21 CFR 872.4130 - Intraoral dental drill.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Intraoral dental drill. 872.4130 Section 872.4130...) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4130 Intraoral dental drill. (a) Identification. An intraoral dental drill is a rotary device intended to be attached to a dental handpiece to drill holes...

  19. 21 CFR 872.4130 - Intraoral dental drill.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Intraoral dental drill. 872.4130 Section 872.4130...) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4130 Intraoral dental drill. (a) Identification. An intraoral dental drill is a rotary device intended to be attached to a dental handpiece to drill holes...

  20. 21 CFR 872.4130 - Intraoral dental drill.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Intraoral dental drill. 872.4130 Section 872.4130...) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4130 Intraoral dental drill. (a) Identification. An intraoral dental drill is a rotary device intended to be attached to a dental handpiece to drill holes...

  1. An Overview of Dental Radiology. NCHCT Monograph Series.

    ERIC Educational Resources Information Center

    Manny, Edward F.; And Others

    This overview of dental radiology contains sections on demographics, equipment, dental radiology quality assurance, efficacy, dental radiology education curricula, professional organizations' guidelines for training and use, and state activities. In section 1 dental personnel, population of dental personnel, employment and earning prospects,…

  2. Creating a Successful School-Based Mobile Dental Program

    ERIC Educational Resources Information Center

    Jackson, David M.; Jahnke, Lauren R.; Kerber, Lisa; Nyer, Genie; Siemens, Kammi; Clark, Carol

    2007-01-01

    Background: Dental disease is one of the leading causes of school absenteeism for children. This article describes the creation and evolution of the St. David's Dental Program, a mobile school-based dental program for children. Methods: The dental program is a collaboration of community partners in Central Texas that provides free dental care to…

  3. The Level of Dental Anxiety and Dental Status in Adult Patients

    PubMed Central

    Dobros, Katarzyna; Hajto-Bryk, Justyna; Wnek, Anna; Zarzecka, Joanna; Rzepka, Dominik

    2014-01-01

    Background: The present study aimed to assess potential correlation between dental anxiety and overall dental status in adult patients, in consideration of the frequency of dental appointments and individual dental hygiene practices. Materials and Methods: Individual dental anxiety levels were assessed with the aid of the Corah’s dental anxiety scale (DAS). The study embraced 112 patients of the University Dental Clinic, Kraków. Following clinical and X-ray exams, respectively, decayed, missing and filled teeth (DMFT) index and dental treatment index (DTI) were computed for each study subject. Results: Mean DAS among the 112 subjects under study was 9.41 standard deviation (SD = 3.36). Mean DMFT value was 15.86 (SD = 7.00), whereas DTI value was 0.76 (SD = 0.27). The number of decayed teeth and an individual dental anxiety level were found to be correlated (r = 0.26). Higher dental anxiety correlated with lower DTI value (r = −0.22) and lesser frequency of dental appointments (r = 0.22). Conclusions: Individual dental anxiety level appears to impact overall dental status, frequency of dental appointments and everyday oral health practices. Every conceivable effort should therefore be undertaken with a view to effectively diminishing dental anxiety levels in the patients. How to cite the article: Dobros K, Hajto-Bryk J, Wnęk A, Zarzecka J, Rzepka D. The level of dental anxiety and dental status in adult patients. J Int Oral Health 2014;6(3):11-4. PMID:25083026

  4. Fate map of the dental mesenchyme: dynamic development of the dental papilla and follicle.

    PubMed

    Rothová, Michaela; Peterková, Renata; Tucker, Abigail S

    2012-06-15

    At the bud stage of tooth development the neural crest derived mesenchyme condenses around the dental epithelium. As the tooth germ develops and proceeds to the cap stage, the epithelial cervical loops grow and appear to wrap around the condensed mesenchyme, enclosing the cells of the forming dental papilla. We have fate mapped the dental mesenchyme, using in vitro tissue culture combined with vital cell labelling and tissue grafting, and show that the dental mesenchyme is a much more dynamic population then previously suggested. At the bud stage the mesenchymal cells adjacent to the tip of the bud form both the dental papilla and dental follicle. At the early cap stage a small population of highly proliferative mesenchymal cells in close proximity to the inner dental epithelium and primary enamel knot provide the major contribution to the dental papilla. These cells are located between the cervical loops, within a region we have called the body of the enamel organ, and proliferate in concert with the epithelium to create the dental papilla. The condensed dental mesenchymal cells that are not located between the body of the enamel organ, and therefore are at a distance from the primary enamel knot, contribute to the dental follicle, and also the apical part of the papilla, where the roots will ultimately develop. Some cells in the presumptive dental papilla at the cap stage contribute to the follicle at the bell stage, indicating that the dental papilla and dental follicle are still not defined populations at this stage. These lineage-tracing experiments highlight the difficulty of targeting the papilla and presumptive odontoblasts at early stages of tooth development. We show that at the cap stage, cells destined to form the follicle are still competent to form dental papilla specific cell types, such as odontoblasts, and produce dentin, if placed in contact with the inner dental epithelium. Cell fate of the dental mesenchyme at this stage is therefore determined

  5. The use of dental services for children: implications of the 2010 dental reform in Israel.

    PubMed

    Shahrabani, Shosh; Benzion, Uri; Machnes, Yaffa; Gal, Assaf

    2015-02-01

    Routine dental examinations for children are important for early diagnosis and treatment of dental problems. The level of dental morbidity among Israeli children is higher than the global average. A July 2010 reform of Israel's National Health Insurance Law gradually offers free dental services for children up to age 12. The study examines the use of dental services for children and the factors affecting mothers' decision to take their children for routine checkups. In addition, the study examines the impact of the reform on dental checkups for children in various populations groups. A national representative sample comprising 618 mothers of children aged 5-18 was surveyed by telephone. The survey integrated the principles of the health beliefs model and socio-demographic characteristics. The results show that mothers' decision to take their children for dental checkups is affected by their socio-demographic status and by their health beliefs with respect to dental health. After the reform, the frequency of children's dental checkups significantly increased among vulnerable populations. Therefore, the reform has helped reduce gaps in Israeli society regarding children's dental health. Raising families' awareness of the reform and of the importance of dental health care together with expanding national distribution of approved dental clinics can increase the frequency of dental checkups among children in Israel.

  6. Child Dental Neglect: A Short Review

    PubMed Central

    Ramazani, Nahid

    2014-01-01

    Context: Child dental neglect is a terrible tragedy with a high prevalence. Dealing with this issue is important regarding psychological and physical health policies. The current review was conducted to provide health professionals insight into the different aspects of child dental neglect as reported in previous literature. Evidence Acquisition: Our review was prepared through an electronic search using Pub Med, Science Direct, Medline, Google, Cochran Library, Google Scholar and EMBASE databases. Relevant papers published since 2000 until now in English, discussing child dental neglect were retrieved. Both original and review papers were included. Eligible articles were fully read by the author. A data form was used to record useful findings. Results: Distinguishing the direct and indirect signs of dental neglect is the first step for improvement of this matter. The dental team are the main professionals who can improve parental knowledge about the consequences of child dental neglect. Victims suffer from short and long-term adverse outcomes. Collaborative attempts need to be made by different health professionals to deal with this problem. Conclusions: Child dental neglect has many long-term impacts. The main professionals who are responsible for identification, intervention and treatment of child dental neglect are dental practitioners. However, other professionals cannot ignore this task. Finally, child dental neglect, despite its derivative outcomes, may be a presentation of a broader maltreatment. PMID:25741483

  7. Dental health status of liver transplant candidates.

    PubMed

    Guggenheimer, James; Eghtesad, Bijan; Close, John M; Shay, Christine; Fung, John J

    2007-02-01

    A prerequisite dental evaluation is usually recommended for potential organ transplant candidates. This is based on the premise that untreated dental disease may pose a risk for infection and sepsis, although there is no evidence that this has occurred in organ transplant candidates or recipients. The purpose of this study was to assess the prevalence of dental disease and oral health behaviors in a sample of liver transplant candidates (LTCs). Oral examinations were conducted on 300 LTCs for the presence of gingivitis, dental plaque, dental caries, periodontal disease, edentulism, and xerostomia. The prevalence of these conditions was compared with oral health data from national health surveys and examined for possible associations with most recent dental visit, smoking, and type of liver disease. Significant risk factors for plaque-related gingivitis included intervals of more than 1 yr since the last dental visit (P = 0.004), smoking (P = 0.03), and diuretic therapy (P = 0.005). Dental caries and periodontal disease were also significantly associated with intervals of more than 1 yr since the last dental visit (P = 0.004). LTCs with viral hepatitis or alcoholic cirrhosis had the highest smoking rate (78.8%). Higher rates of edentulism occurred among older LTCs who were less likely to have had a recent dental evaluation (mean 88 months). In conclusion, intervals of more than 1 yr since the last dental visit, smoking, and diuretic therapy appear to be the most significant determinants of dental disease and the need for a pretransplantation dental screening evaluation in LTCs. Edentulous patients should have periodic examinations for oral cancer.

  8. Mapping the literature of dental assisting.

    PubMed Central

    Hook, S A; Wagner, C F

    1999-01-01

    The purpose of this study was to identify core journals and the databases that provide access to these journals for the field of dental assisting. This study was completed as a part of the Medical Library Association (MLA) Nursing and Allied Health Resources Section's project to map the literature of allied health. There were three original journals selected for analysis using the prescribed methodology, Dental Assistant, the journal of the American Dental Assistants Association; Journal of the CDAA, the journal of the Canadian Dental Assistants' Association; and Dental Teamwork, published by the American Dental Association. Dental Teamwork ceased publication in December 1996; however, it was considered a necessary part of the analysis due to its extensive coverage of dental assisting as well as its numerous scientific articles with references. In Dental Assistant, there were 16 source articles, containing 206 citations. In Dental Teamwork, there were 31 source articles with 308 citations. In Journal of the CDAA, there were only 3 source articles with 14 citations. Bradford's Law of Scattering was applied to the journal citations. Four databases, MEDLINE, the Cumulative Index to Nursing and Allied Health Literature, EMBASE/Excerpta Medica, and HEALTH were analyzed for their coverage of these cited journals. This study may encourage the dental assisting profession to take a close look at its existing journals and to consider enhancing the content of these journals or the publication of additional journals in the field. Dental assistants of today need substantive literature that deals with all aspects of their chosen profession in order to meet the challenges of providing dental health care in the future. PMID:10427427

  9. Communication in dental medicine: importance in motivating elderly dental patients.

    PubMed

    Scutariu, Mihaela Monica; Forna, Norina

    2013-01-01

    Dental services for elderly patients are characterized by a series of particularities related to the vulnerability of this age group, which is affected by various co morbidities, and the diminished physical, cognitive and financial capacities. Finding ways to keep elderly patients coming to a dental office is possible by improving the dentist-patient relationship and implicitly the quality of care by increasing the self-esteem of the elderly and their place in society, by increasing the role of oral health in the quality of life, and here we refer to the pleasure of eating, the pleasant physical aspect and normal diction. The present paper presents the psychological aspects that interfere in the communication process between the dentist and the elderly patient and the changes motivation undergoes when people are in pain. These data can sometimes change the reticent attitude of the dentist towards the elderly patient which is often considered to be a risk patient.

  10. Highly-translucent, strong and aging-resistant 3Y-TZP ceramics for dental restoration by grain boundary segregation.

    PubMed

    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.

  11. Dental Pulp Defence and Repair Mechanisms in Dental Caries

    PubMed Central

    Farges, Jean-Christophe; Alliot-Licht, Brigitte; Renard, Emmanuelle; Ducret, Maxime; Gaudin, Alexis; Smith, Anthony J.; Cooper, Paul R.

    2015-01-01

    Dental caries is a chronic infectious disease resulting from the penetration of oral bacteria into the enamel and dentin. Microorganisms subsequently trigger inflammatory responses in the dental pulp. These events can lead to pulp healing if the infection is not too severe following the removal of diseased enamel and dentin tissues and clinical restoration of the tooth. However, chronic inflammation often persists in the pulp despite treatment, inducing permanent loss of normal tissue and reducing innate repair capacities. For complete tooth healing the formation of a reactionary/reparative dentin barrier to distance and protect the pulp from infectious agents and restorative materials is required. Clinical and in vitro experimental data clearly indicate that dentin barrier formation only occurs when pulp inflammation and infection are minimised, thus enabling reestablishment of tissue homeostasis and health. Therefore, promoting the resolution of pulp inflammation may provide a valuable therapeutic opportunity to ensure the sustainability of dental treatments. This paper focusses on key cellular and molecular mechanisms involved in pulp responses to bacteria and in the pulpal transition between caries-induced inflammation and dentinogenic-based repair. We report, using selected examples, different strategies potentially used by odontoblasts and specialized immune cells to combat dentin-invading bacteria in vivo. PMID:26538821

  12. [Dental care, dental diseases and dentistry in antiquity].

    PubMed

    Józsa, László

    2009-01-01

    Numerous written relicts, belletristic works (poems of Martial, Juvenal, Ovid etc.) indicate that oral hygiene and its tools (toothbrush, toothpick, use of tooth pastes and tooth-powder) were used long before our times. Already ancient people started to remove, file, dye and inlay teeth. The teeth were dyed red, green or black in Egypt, red or brown (with henna or betel) in India, white by Romans. The teeth decoration has a long but forgotten history. The most skillful and artistic work was done by the Maya's between 900 BC and 1500 AD. The modification of contours (more than fifty forms) of the incisors were practiced also in Mesoamerica. Dentistry was surely practiced in ancient Egypt, India, China, Greece and Rome, while odontology and especially suitable dental appliances arose only by Etruscan. Dental prosthesis, including bridges and simple retention bands were invented by the Etruscans 2500 years ago. These Etruscan bridges were worn mostly by females, suggesting that cosmetics was the principal dental concern. Some,--if not all--of the Roman and other prostheses have been purely ornamental. Orthodontic appliances are also Etruscan invention. The holes caused by caries were filled with garlic, incense, caraway seed in Egypt, with wood or lead in Rome, and with "silver-paste" (amalgam) in ancient China. The toothache was cured with poppy-tee, or hashish and nightshade plants (Solanaceae) in Egypt, Greece, Roman Empire while with coca (Erythroxylon coca) in South-America.

  13. The microbiology of the acute dental abscess.

    PubMed

    Robertson, D; Smith, A J

    2009-02-01

    The acute dental abscess is frequently underestimated in terms of its morbidity and mortality. The risk of potential serious consequences arising from the spread of a dental abscess is still relevant today with many hospital admissions for dental sepsis. The acute dental abscess is usually polymicrobial comprising facultative anaerobes, such as viridans group streptococci and the Streptococcus anginosus group, with predominantly strict anaerobes, such as anaerobic cocci, Prevotella and Fusobacterium species. The use of non-culture techniques has expanded our insight into the microbial diversity of the causative agents, identifying such organisms as Treponema species and anaerobic Gram-positive rods such as Bulleidia extructa, Cryptobacterium curtum and Mogibacterium timidum. Despite some reports of increasing antimicrobial resistance in isolates from acute dental infection, the vast majority of localized dental abscesses respond to surgical treatment, with antimicrobials limited to spreading and severe infections. The microbiology and treatment of the acute localized abscess and severe spreading odontogenic infections are reviewed.

  14. Optical detection dental disease using polarized light

    DOEpatents

    Everett, Matthew J.; Colston, Jr., Billy W.; Sathyam, Ujwal S.; Da Silva, Luiz B.; Fried, Daniel

    2003-01-01

    A polarization sensitive optical imaging system is used to detect changes in polarization in dental tissues to aid the diagnosis of dental disease such as caries. The degree of depolarization is measured by illuminating the dental tissue with polarized light and measuring the polarization state of the backscattered light. The polarization state of this reflected light is analyzed using optical polarimetric imaging techniques. A hand-held fiber optic dental probe is used in vivo to direct the incident beam to the dental tissue and collect the reflected light. To provide depth-resolved characterization of the dental tissue, the polarization diagnostics may be incorporated into optical coherence domain reflectometry and optical coherence tomography (OCDR/OCT) systems, which enables identification of subsurface depolarization sites associated with demineralization of enamel or bone.

  15. Diagnosis and management of dental wear.

    PubMed

    Harpenau, Lisa A; Noble, Warden H; Kao, Richard T

    2012-01-01

    Dental wear is loss of tooth structure resulting from erosion, attrition, abrasion and, possibly, abfraction. Clinical/experimental data suggest no single damaging mechanism, but rather simultaneous interaction of these destructive processes. The most important interaction is abrasion/attrition potentiated by dental erosion. Awareness of this pathosis is not well-appreciated by the public and dental professionals because the signs may be subtle. This article focuses on recognizing, diagnosing and managing dental wear. Dental wear is a challenging problem for clinicians because of the subtlety of early changes; confusion about the etiology of the problem; and the dilemma of when or how to manage the etiology. Unfortunately, failure to recognize and manage the process often results in inaction until the breakdown is severe. At that point, the structural breakdown is so advanced that major rehabilitative treatment often is needed. This introductory article discusses diagnosing and managing dental wear.

  16. Personality types of Chinese dental school applicants.

    PubMed

    Wu, Shengjun; Miao, Danmin; Zhu, Xia; Luo, Zhengxue; Liu, Xufeng

    2007-12-01

    This his article reports the findings of a study conducted to investigate the personality types of Chinese dental school applicants. The Chinese version of the Myers-Briggs Type Indicator (MBTI) (Form G) was used to assess the personality styles of 332 dental school applicants from the mainland of China. The results of the MBTI for Chinese dental school applicants were compared with a previous study of applicants from the U.K. A higher percentage of this group of Chinese applicants scored higher for Introversion (I) than Extroversion (E); both Chinese and English applicants preferred Judging (J) to Perceiving (P). The dominant personality types in Chinese applicants were ISTJ, ESTJ, and ISFP. The findings suggest that the personality types of Chinese dental students may be somewhat different from the personality profiles exhibited by dental students from other nations. The findings may be of value to individuals who desire to investigate personality type differences among dental students with different cultural backgrounds.

  17. Dental technicians: regulation and quality assurance.

    PubMed

    Newsome, P R H

    2011-01-08

    For many years, dental technicians were largely self-regulated and left to work without any undue interference from, or legislation by, outside authorities. This situation has changed somewhat dramatically in recent years, primarily as a result of a) mandatory General Dental Council (GDC) registration of UK-based dental technicians and b) the requirement to comply with certain EC directives governing the provision of dental appliances. There seems to be some confusion, however, about these various changes and the ensuing ramifications for dental practitioners. The purpose of this paper is firstly to clarify the various regulatory issues currently surrounding technician registration and the provision of laboratory work ('Made in Britain' or otherwise) and secondly to explore the various internationally-recognised quality assurance standards that can be applied to the production of such work in order to assist dentists in gauging quality-related claims made by dental laboratories, both in the UK and overseas.

  18. Dental archives based on images

    NASA Astrophysics Data System (ADS)

    Dostalova, Tatjana; Smutny, Vladimir

    1997-05-01

    This paper describes the Orthoscope, an equipment for acquisition, processing, and archiving of images of patients mouth or skin. The equipment can capture and process images of single tooth, group of teeth or the whole dental arc. A dentist can easily observe the situation in mouth, demonstrate intended plan of treatment to patient and document its results. A dermatologist can evaluate treatment progress. Unlike other methods, our device shows geometrically undistorted calibrated image.The presented equipment is intended for daily practice. The image processing module is connected to an insurance office system and medical archives. This eliminates time consuming literal description of the patient dental/dermatological status. The images can be used later checking of the diagnosis and treatment.

  19. Soft skills and dental education.

    PubMed

    Gonzalez, M A G; Abu Kasim, N H; Naimie, Z

    2013-05-01

    Soft skills and hard skills are essential in the practice of dentistry. While hard skills deal with technical proficiency, soft skills relate to a personal values and interpersonal skills that determine a person's ability to fit in a particular situation. These skills contribute to the success of organisations that deal face-to-face with clients. Effective soft skills benefit the dental practice. However, the teaching of soft skills remains a challenge to dental schools. This paper discusses the different soft skills, how they are taught and assessed and the issues that need to be addressed in their teaching and assessment. The use of the module by the Faculty of Dentistry, University of Malaya for development of soft skills for institutions of higher learning introduced by the Ministry of Higher Education, Malaysia.

  20. Dental gemination: report of case.

    PubMed

    Hernandez-Guisado, J M; Torres-Lagares, D; Infante-Cossio, P; Gutierrez-Perez, J L

    2002-01-01

    Dental anomalies can be classified in different groups: anomalies of volume, anomalies of number, anomalies of form, anomalies of position and anomalies by union. Of the latter, we distinguish between fusion, alveolus-dental gemination, concrescence, coalescence and anchylosis. Gemination is more frequent in the anterior teeth, although it can also affect the bicuspids and molars, being an anomaly of infrequent union (prevalence 0.5%). We present the case of a young male patient age 19, without medical antecedents of interest, that goes to consultation for repeated inflammatory accidents at level of the inferior left retromolar area. These episodes are caused by a semi-impacted inferior third molar that is fused to a supernumerary fourth molar, sharing its roots, crown, pulp chambers and canals. After the appropriate radiologic study and suitable planning, the semi-impacted third molar was extracted under local anaesthesia and without any other complications during or after the operation.