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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. 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. PMID:26342288

  3. Veneers

    MedlinePlus

    ... Risk for Early Childhood Tooth Decay? What is Dental Amalgam (Silver Filling)? How Do I Care for My Child's Baby Teeth? What is Orofacial Pain? Pacifiers Have Negative and Positive Effects Learn what ...

  4. 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.

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

    NASA Astrophysics Data System (ADS)

    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.

  6. 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. PMID:25247394

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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. PMID:27478376

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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. PMID:27293439

  19. 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

  20. 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. PMID:19029080

  1. Ultimate ceramic veneer: a laboratory-guided preparation technique for minimally invasive laminate veneers.

    PubMed

    De Andrade, Oswaldo Scopin; Hirata, Ronaldo; Celestrino, Marcos; Seto, Marcio; Siqueira, Sérgio; Nahas, Rodrigo

    2012-06-01

    Clinical success of ceramic laminate veneers depends on material selection, bonding procedures, controlled laboratory steps, and enamel preservation. Enamel preservation is the most critical because excessive tooth preparation can expose dentin reducing bond strength, which is a factor that can cause a decrease in long-term clinical success. The proposed technique based on carefully treatment planning developed between clinician and dental technician helps to maximize enamel preservation, which is an important element for clinical success. PMID:22856034

  2. Residual Stresses in Porcelain-veneered Zirconia Prostheses

    PubMed Central

    Baldassarri, Marta; Stappert, Christian F. J.; Wolff, Mark S.; Thompson, Van P.; Zhang, Yu

    2012-01-01

    Objectives Compressive stress has been intentionally introduced into the overlay porcelain of zirconia-ceramic prostheses to prevent veneer fracture. However, recent theoretical analysis has predicted that the residual stresses in the porcelain may be also tensile in nature. This study aims to determine the type and magnitude of the residual stresses in the porcelain veneers of full-contour fixed-dental prostheses (FDPs) with an anatomic zirconia coping design and in control porcelain with the zirconia removed using a well-established Vickers indentation method. Methods Six 3-unit zirconia FDPs were manufactured (NobelBiocare, Gothenburg, Sweden). Porcelain was hand-veneered using a slow cooling rate. Each FDP was sectioned parallel to the occlusal plane for Vickers indentations (n = 143; load = 9.8 N; dwell time = 5 s). Tests were performed in the veneer of porcelain-zirconia specimens (bilayers, n = 4) and porcelain specimens without zirconia cores (monolayers, n = 2). Results The average crack lengths and standard deviation, in the transverse and radial directions (i.e. parallel and perpendicular to the veneer/core interface, respectively), were 67 ± 12 μm and 52 ± 8 μm for the bilayers and 64 ± 8 μm and 64 ± 7 μm for the monolayers. These results indicated a major hoop compressive stress (~40 to 50 MPa) and a moderate radial tensile stress (~10 MPa) in the bulk of the porcelain veneer. Significance Vickers indentation is a powerful method to determine the residual stresses in veneered zirconia systems. Our findings revealed the presence of a radial tensile stress in the overlay porcelain, which may contributed to the large clinical chip fractures observed in these prostheses. PMID:22578663

  3. 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. PMID:25156092

  4. 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

  5. Planetary science: Ubiquitous late veneer

    NASA Astrophysics Data System (ADS)

    Brenan, James

    2012-09-01

    Iron-loving elements are thought to have been added to Mars, Earth and the Moon after core formation. An analysis of meteorites formed in the first two to three million years of Solar System history suggests that a similar late veneer was added elsewhere too.

  6. Clinical performance of porcelain laminate veneers: outcomes of the aesthetic pre-evaluative temporary (APT) technique.

    PubMed

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

    2012-12-01

    This article evaluates the long-term clinical performance of porcelain laminate veneers bonded to teeth prepared with the use of an additive mock-up and aesthetic pre-evaluative temporary (APT) technique over a 12-year period. Sixty-six patients were restored with 580 porcelain laminate veneers. The technique, used for diagnosis, esthetic design, tooth preparation, and provisional restoration fabrication, was based on the APT protocol. The influence of several factors on the durability of veneers was analyzed according to pre- and postoperative parameters. With utilization of the APT restoration, over 80% of tooth preparations were confined to the dental enamel. Over 12 years, 42 laminate veneers failed, but when the preparations were limited to the enamel, the failure rate resulting from debonding and microleakage decreased to 0%. Porcelain laminate veneers presented a successful clinical performance in terms of marginal adaptation, discoloration, gingival recession, secondary caries, postoperative sensitivity, and satisfaction with restoration shade at the end of 12 years. The APT technique facilitated diagnosis, communication, and preparation, providing predictability for the restorative treatment. Limiting the preparation depth to the enamel surface significantly increases the performance of porcelain laminate veneers. PMID:23057051

  7. Graded Zirconia Glass for Resistance to Veneer Fracture

    PubMed Central

    Zhang, Y.; Kim, J.-W.

    2010-01-01

    Failures of zirconia-based all-ceramic restorations appear to be predominantly chips and fractures in the porcelain veneer, from occlusally induced sliding contact damage. We hypothesized that such failure may be substantially mitigated by controlled grading of the elastic modulus at the ceramic surface. In this study, we fabricated graded structures by infiltrating glass into zirconia plates, resulting in improved aesthetics and diminished modulus at the surfaces. Individual plates were then embedded in epoxy or cemented to dental composites and subjected to single- or multi-cycle sliding contact. Plates of porcelain-veneered zirconia and monolithic zirconia served as controls. Graded zirconia-glass structures exhibited over 3 times better resistance to single-cycle sliding damage than monolithic zirconia and 25 times better than veneered zirconia, and had a fatigue sliding damage resistance comparable with that of monolithic zirconia. These zirconia-glass materials can be engineered in shades from white to yellow, and have potentially better cementation properties than homogeneous zirconia. PMID:20651092

  8. 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

  9. Modified maximum tangential stress criterion for fracture behavior of zirconia/veneer interfaces.

    PubMed

    Mirsayar, M M; Park, P

    2016-06-01

    The veneering porcelain sintered on zirconia is widely used in dental prostheses, but repeated mechanical loadings may cause a fracture such as edge chipping or delamination. In order to predict the crack initiation angle and fracture toughness of zirconia/veneer bi-layered components subjected to mixed mode loadings, the accuracy of a new and traditional fracture criteria are investigated. A modified maximum tangential stress criterion considering the effect of T-stress and critical distance theory is introduced, and compared to three traditional fracture criteria. Comparisons to the recently published fracture test data show that the traditional fracture criteria are not able to properly predict the fracture initiation conditions in zirconia/veneer bi-material joints. The modified maximum tangential stress criterion provides more accurate predictions of the experimental results than the traditional fracture criteria. PMID:26807673

  10. 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

  11. 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

  12. 13. VIEW LOOKING NORTHEAST, SHOWING SHIPPING ROOMS AND VENEER MILL ...

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

    13. VIEW LOOKING NORTHEAST, SHOWING SHIPPING ROOMS AND VENEER MILL (AT RIGHT), AND ENGINE ROOM (AT LEFT) - Ichabod T. Williams & Sons Sawmill & Veneer Plant, Roosevelt Avenue at Carteret Avenue, Carteret, Middlesex County, NJ

  13. Esthetic integration between ceramic veneers and composite restorations: a case report

    PubMed Central

    Farronato, Davide; Mangano, Francesco; Pieroni, Stefano; Giudice, Giuseppe Lo; Briguglio, Roberto; Briguglio, Francesco

    2012-01-01

    Summary The tooth structure preservation is the best way to postpone more invasive therapies. Especially in young patients more conservative techniques should be applied. Bonded porcelain veneers and even more the direct composite restorations, are the two therapeutic procedures that require the fewer sacrifice of dental tissue, finalized to the optimal recovery of aesthetic and functional outcome. Although the two techniques require different methods and materials, is possible to achieve a correct integration of both the methods by some technical and procedural measures. In the presented case is planned a rehabilitation of the four upper incisors by ceramic veneers and direct composite restorations. Care is taken for the surface treatment of ceramic restorations, with the objective of achieving integration, not only between natural teeth and restorations, but also between the different materials in use. The purpose of this article is to show how a proper design of the treatment plan leads to obtain predictable results with both direct and indirect techniques. PMID:23386935

  14. 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. PMID:26345104

  15. 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

  16. Indirect laminate veneer: a conservative novel approach.

    PubMed

    Prajapati, Paranjay; Sethuraman, Rajesh; Naveen, Y G; Patel, Jayanti R

    2013-01-01

    Various treatment options and materials are available for restoration of an endodontically treated tooth. Laminate veneer is conservative treatment usually employed for aesthetic correction or improvement. The indirect composite is available in a wide range of shades and specific characterisation is easily performed chair side in the operatory area, which makes it a quick procedure and time saving for both the patient and the dentist. The physical properties and optical properties are good enough to use it as indirect restorative material, so in this particular case it was the material of choice for fabrication of laminate veneer on anterior tooth. In this case, the endodontically treated tooth with a fractured incisal edge was restored with indirect composite material. PMID:23975914

  17. 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

  18. Minimally invasive veneers: current state of the art.

    PubMed

    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

  19. Time-dependent fracture probability of bilayer, lithium-disilicate-based glass-ceramic molar crowns as a function of core/veneer thickness ratio and load orientation

    PubMed Central

    Anusavice, Kenneth J.; Jadaan, Osama M.; Esquivel–Upshaw, Josephine

    2013-01-01

    Recent reports on bilayer ceramic crown prostheses suggest that fractures of the veneering ceramic represent the most common reason for prosthesis failure. Objective The aims of this study were to test the hypotheses that: (1) an increase in core ceramic/veneer ceramic thickness ratio for a crown thickness of 1.6 mm reduces the time-dependent fracture probability (Pf) of bilayer crowns with a lithium-disilicate-based glass-ceramic core, and (2) oblique loading, within the central fossa, increases Pf for 1.6-mm-thick crowns compared with vertical loading. Materials and methods Time-dependent fracture probabilities were calculated for 1.6-mm-thick, veneered lithium-disilicate-based glass-ceramic molar crowns as a function of core/veneer thickness ratio and load orientation in the central fossa area. Time-dependent fracture probability analyses were computed by CARES/Life software and finite element analysis, using dynamic fatigue strength data for monolithic discs of a lithium-disilicate glass-ceramic core (Empress 2), and ceramic veneer (Empress 2 Veneer Ceramic). Results Predicted fracture probabilities (Pf) for centrally-loaded 1,6-mm-thick bilayer crowns over periods of 1, 5, and 10 years are 1.2%, 2.7%, and 3.5%, respectively, for a core/veneer thickness ratio of 1.0 (0.8 mm/0.8 mm), and 2.5%, 5.1%, and 7.0%, respectively, for a core/veneer thickness ratio of 0.33 (0.4 mm/1.2 mm). Conclusion CARES/Life results support the proposed crown design and load orientation hypotheses. Significance The application of dynamic fatigue data, finite element stress analysis, and CARES/Life analysis represent an optimal approach to optimize fixed dental prosthesis designs produced from dental ceramics and to predict time-dependent fracture probabilities of ceramic-based fixed dental prostheses that can minimize the risk for clinical failures. PMID:24060349

  20. 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

  1. 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

  2. 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

  3. Feldspathic veneers: what are their indications?

    PubMed

    McLaren, Edward A; LeSage, Brian

    2011-04-01

    Many different materials and treatment options are available in esthetic and restorative dentistry. Various newer products, such as pressed ceramics, offer enhanced functionality; however, in thinner dimensions, they lack the inherent esthetic beauty of traditional materials such as feldspathic porcelain. As patient demands for better esthetics have increased in recent years, so too has the need for restorative materials that closely mimic the patient's natural dentition. Initially used for the creation of porcelain dentures, feldspathic porcelain has emerged as the premier esthetic material for custom veneer restorations. In recent years, the use of hand-layered powder/liquid feldspathic porcelain has been revived based on its highly esthetic values and little-to-no preparation requirements. By keeping preparation to a minimum, less tooth structure is lost and procedures are much less invasive, which is exactly what patients desire. PMID:21560742

  4. Splinted Porcelain Laminate Veneers With a Natural Tooth Pontic: A Provisional Approach for Conservative and Esthetic Treatment of a Challenging Case.

    PubMed

    Jang, J-H; Lee, S-H; Paek, J; Kim, S-Y

    2015-01-01

    Esthetic rehabilitation of discolored anterior teeth is always a great challenge, especially in the presence of pathology. Fortunately, conservative management in the esthetic zone has become more feasible in compromised cases because of the development of restorative materials and advances in dental adhesives. This report presents a complicated case of a patient with tetracycline-related discoloration, multiple root resorption, and a periapical lesion. Treatment was conservative and used a natural tooth pontic and splinted porcelain laminate veneers. PMID:26332738

  5. 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

  6. Influence of cooling rate on zirconia/veneer interfacial adhesion.

    PubMed

    Göstemeyer, Gerd; Jendras, Michael; Dittmer, Marc P; Bach, Friedrich-Wilhelm; Stiesch, Meike; Kohorst, Philipp

    2010-12-01

    Slow cooling firing schedules have recently been introduced by some manufacturers to reduce chipping complications in zirconia-based core/veneer composites. The aim of this study was to test the hypothesis that these firing schedules may influence the bond strength between the zirconia core and veneering ceramic. Four different veneering ceramics recommended for zirconia (Lava Ceram, Triceram, VM9 and Zirox) were fired onto rectangular shaped Y-TZP specimens (Lava Frame) and cooled using a rapid or a slow cooling rate. The resulting bilayer specimens were notched, loaded in a four-point bending test and load-displacement curves were recorded. The critical load to induce stable crack extension at the core/veneer interface was determined, in order to calculate the strain energy release rate (G, Jm⁻²). Additionally, dilatometric measurements of the veneering ceramics were performed to determine the coefficient of thermal expansion (α, ppm.K⁻¹) between 50 and 450°C (α₁) and in the temperature region above the glass transition temperature (α₂). Discrepancies between α₂ and α₁ (Δα) were calculated. For all core/veneer compositions G values were lower for the slowly cooled specimens than for the rapidly cooled specimens. Significant differences with respect to the firing schedule were found in the Triceram and VM9 groups (P<0.05). The reductions in G values correlated with Δα. The bond strength between the zirconia core and the veneer decreased with the slow cooling rate. These results indicate that slow cooling of zirconia restorations may increase the risk of adhesive delamination failures between the core and veneer. PMID:20601242

  7. 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

  8. Effect of surface roughness on flexural strength of veneer ceramics.

    PubMed

    Fischer, H; Schäfer, M; Marx, R

    2003-12-01

    The strength of ceramic restorations depends on the occlusal surface roughness of the veneering porcelain, which is influenced by the final preparation. The hypothesis of the study was that roughnesses below a critical microscopic defect size--based only on fracture mechanics considerations--also affect flexural strength. The bending failure stress was evaluated on standard specimens of 4 veneer ceramics with 4 different surfaces of defined roughnesses, respectively. A linear correlation was found between roughness and failure stress. A "roughness-free" failure stress value was predicted for each tested material. This theoretical value can represent the "true" strength of the respective ceramic material. We conclude from our results that the final preparation of a ceramic restoration is critical to the strength of the material, and that ceramic veneering materials can be compared more objectively with respect to their strength by means of roughness-free strength values. PMID:14630897

  9. Lunar tungsten isotopic evidence for the late veneer.

    PubMed

    Kruijer, Thomas S; Kleine, Thorsten; Fischer-Gödde, Mario; Sprung, Peter

    2015-04-23

    According to the most widely accepted theory of lunar origin, a giant impact on the Earth led to the formation of the Moon, and also initiated the final stage of the formation of the Earth's core. Core formation should have removed the highly siderophile elements (HSE) from Earth's primitive mantle (that is, the bulk silicate Earth), yet HSE abundances are higher than expected. One explanation for this overabundance is that a 'late veneer' of primitive material was added to the bulk silicate Earth after the core formed. To test this hypothesis, tungsten isotopes are useful for two reasons: first, because the late veneer material had a different (182)W/(184)W ratio to that of the bulk silicate Earth, and second, proportionally more material was added to the Earth than to the Moon. Thus, if a late veneer did occur, the bulk silicate Earth and the Moon must have different (182)W/(184)W ratios. Moreover, the Moon-forming impact would also have created (182)W differences because the mantle and core material of the impactor with distinct (182)W/(184)W would have mixed with the proto-Earth during the giant impact. However the (182)W/(184)W of the Moon has not been determined precisely enough to identify signatures of a late veneer or the giant impact. Here, using more-precise measurement techniques, we show that the Moon exhibits a (182)W excess of 27 ± 4 parts per million over the present-day bulk silicate Earth. This excess is consistent with the expected (182)W difference resulting from a late veneer with a total mass and composition inferred from HSE systematics. Thus, our data independently show that HSE abundances in the bulk silicate Earth were established after the giant impact and core formation, as predicted by the late veneer hypothesis. But, unexpectedly, we find that before the late veneer, no (182)W anomaly existed between the bulk silicate Earth and the Moon, even though one should have arisen through the giant impact. The origin of the homogeneous (182

  10. 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

  11. 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

  12. 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.

  13. 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

  14. Tensile strength of bilayered ceramics and corresponding glass veneers

    PubMed Central

    Champirat, Tharee; Jirajariyavej, Bundhit

    2014-01-01

    PURPOSE To investigate the microtensile bond strength between two all-ceramic systems; lithium disilicate glass ceramic and zirconia core ceramics bonded with their corresponding glass veneers. MATERIALS AND METHODS Blocks of core ceramics (IPS e.max® Press and Lava™ Frame) were fabricated and veneered with their corresponding glass veneers. The bilayered blocks were cut into microbars; 8 mm in length and 1 mm2 in cross-sectional area (n = 30/group). Additionally, monolithic microbars of these two veneers (IPS e.max® Ceram and Lava™ Ceram; n = 30/group) were also prepared. The obtained microbars were tested in tension until fracture, and the fracture surfaces of the microbars were examined with fluorescent black light and scanning electron microscope (SEM) to identify the mode of failure. One-way ANOVA and the Dunnett's T3 test were performed to determine significant differences of the mean microtensile bond strength at a significance level of 0.05. RESULTS The mean microtensile bond strength of IPS e.max® Press/IPS e.max® Ceram (43.40 ± 5.51 MPa) was significantly greater than that of Lava™ Frame/Lava™ Ceram (31.71 ± 7.03 MPa)(P<.001). Fluorescent black light and SEM analysis showed that most of the tested microbars failed cohesively in the veneer layer. Furthermore, the bond strength of Lava™ Frame/Lava™ Ceram was comparable to the tensile strength of monolithic glass veneer of Lava™ Ceram, while the bond strength of bilayered IPS e.max® Press/IPS e.max® Ceram was significantly greater than tensile strength of monolithic IPS e.max® Ceram. CONCLUSION Because fracture site occurred mostly in the glass veneer and most failures were away from the interfacial zone, microtensile bond test may not be a suitable test for bonding integrity. Fracture mechanics approach such as fracture toughness of the interface may be more appropriate to represent the bonding quality between two materials. PMID:25006377

  15. 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

  16. 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

  17. 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 ...

  18. 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

  19. 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. PMID:18362320

  20. Bonding a veneered zirconia anterior fixed partial denture.

    PubMed

    Lawson, Nathaniel C; Chavali, Ramakiran; Burgess, John O

    2015-01-01

    This case report documents the rationale and procedure for bonding a veneered zirconia restoration. A three-unit zirconia fixed partial denture (FPD) was fabricated with facial and incisal porcelain veneering. The intaglio surface of the prosthesis was abraded with 50-μm aluminum oxide (Al2O3) particles and coated with one layer of a 10-methacryloxydecyl dihydrogen phosphate (MDP) primer. The FPD was tried into the mouth and occlusal adjustment was performed with a fine grit diamond, and then it was polished with zirconia polishing points. The intaglio surfaces of the abutment crowns were cleaned with 37% phosphoric acid and rinsed. A self-etch adhesive was applied to the tooth preparations and light-cured, and the crowns were filled with cement and seated. Excess cement was immediately wiped away with a brush, followed by spot-curing of the margins. The case demonstrates that, when properly designed, veneered zirconia restorations offer acceptable esthetic and mechanical properties for anterior FPDs. PMID:25822406

  1. 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

  2. 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

  3. Application of Monolithic Zirconia Ceramics in Dental Practice: A Case History Report.

    PubMed

    Kim, Hee-Kyung; Kim, Sung-Hun; Lee, Jai-Bong; Han, Jung-Suk; Yeo, In-Sung

    2016-01-01

    Monolithic zirconia restorations increasingly have been used in dental practice in recent years and demonstrate superior mechanical performance compared with porcelain-veneered zirconia restorations. Recent advances in manufacturing technology have made possible the fabrication of translucent monolithic zirconia ceramics. This case report describes three clinical examples of monolithic zirconia fixed dental prostheses being used in the anterior and posterior regions and exhibiting acceptable esthetic results. PMID:27611758

  4. 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. PMID:22262632

  5. 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... you operate a softwood veneer dryer, you must develop a plan for review and approval for...

  6. 40 CFR 63.2265 - Initial compliance demonstration for a softwood veneer dryer.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 12 2011-07-01 2009-07-01 true Initial compliance demonstration for a softwood veneer dryer. 63.2265 Section 63.2265 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... you operate a softwood veneer dryer, you must develop a plan for review and approval for...

  7. 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

  8. Reliability and fatigue failure modes of implant-supported aluminum-oxide fixed dental prostheses

    PubMed Central

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

    2012-01-01

    Objectives To investigate failure modes and reliability of implant-supported aluminum-oxide three-unit fixed-dental-prostheses (FDPs) using two different veneering porcelains. Material and methods Thirty-six aluminum-oxide FDP-frameworks were CAD/CAM fabricated and either hand-veneered(n=18) or over-pressed(n=18). All FDPs were adhesively luted to custom-made zirconium-oxide-abutments attached to dental implant fixtures (RP-4×13mm). Specimens were stored in water prior to mechanical testing. A Step-Stress-Accelerated-Life-Test (SSALT) with three load/cycles varying profiles was developed based on initial single-load-to-failure testing. Failure was defined by veneer chipping or chipping in combination with framework fracture. SSALT was performed on each FDP inclined 30° with respect to the applied load direction. For all specimens, failure modes were analyzed using polarized-reflected-light-microscopy and scanning-electron-microscopy (SEM). Reliability was computed using Weibull analysis software (Reliasoft). Results The dominant failure mode for the over-pressed FDPs was buccal chipping of the porcelain in the loading area of the pontic, while hand-veneered specimens failed mainly by combined failure modes in the veneering porcelain, framework and abutments. Chipping of the porcelain occurred earlier in the over-pressed specimens (350 N/85k, load/cycles) than in the hand-veneered (600 N/110k)(profile I). Given a mission at 300 N load and 100k or 200 K cycles the computed Weibull reliability (2-sided at 90.0 % confidence bounds) was 0.99(1/0.98) and 0.99(1/0.98) for hand-veneered FDPs, and 0.45(0.76/0.10) and 0.05(0.63/0) for over-pressed FDPs, respectively. Conclusions In the range of average clinical loads (300–700 N), hand-veneered aluminum-oxide FDPs showed significantly less failure by chipping of the veneer than the over-pressed. Hand-veneered FDPs under fatigue loading failed at loads ≥ 600N. PMID:22093019

  9. [Different types of tooth preparation for placement of ceramic veneers].

    PubMed

    Fernández Bodereau, E

    1989-09-01

    Lately the porcelain laminate veneer in the fore-upper sector of the mouth, has gained popularity due to the multiple advantages that it has shown, therefrom the purpose of describing the different reduction techniques according to the function of the laminate restauration. We describe the instruments that will be used and the sequence that should be carried on during the different types of reduction, classifying them in three large groups according to the anomaly presented by the elements to be restored. PMID:2639346

  10. Predictable Outcomes with Porcelain Laminate Veneers: A Clinical Report.

    PubMed

    Pimentel, Welson; Teixeira, Marcelo Lucchesi; Costa, Priscila Paganini; Jorge, Mônica Zacharias; Tiossi, Rodrigo

    2016-06-01

    This clinical report describes how to achieve predictable outcomes for anterior teeth esthetic restorations with porcelain laminate veneers by associating the digital planning and design of the restoration with interim restorations. The previous digital smile design of the restoration eliminates the communication barrier with the patient and assists the clinician throughout patient treatment. Interim restorations (diagnostic mock-ups) further enhance communication with the patient and prevent unnecessary tooth reduction for conservative tooth preparation. Adequate communication between patient and clinician contributes to successful definitive restorations and patient satisfaction with the final esthetic outcome. PMID:26633080

  11. Interfacial adhesion of zirconia/veneer bilayers with different thermal characteristics.

    PubMed

    Freifrau Von Maltzahn, Nadine; Kleibe, Martin; Stiesch, Meike; Hübsch, Christoph; Kohorst, Philipp

    2014-01-01

    The aim of this study was to investigate how changes in the thermal characteristics of veneer ceramics with almost identical chemical and mechanical properties but with different coefficients of thermal expansion (CTE) can modify their interfacial adhesion to zirconia. 48 bilayers made of one Y-TZP ceramic and four veneer ceramics were fabricated (n=12). Thermal residual stresses were calculated on the basis of the CTE and glass transition temperatures. After defined notching all specimens were loaded in a four-point bending test and the critical loads were recorded which induced stable crack extension at the adhesion interface. The strain energy release rate (G, J/m(2)) was calculated and was taken as a measure of interfacial adhesion. The CTE of the veneer ceramics were significantly correlated with their adhesion to Y-TZP (p<0.001). Interfacial adhesion in zirconia/veneer bilayers is predominantly affected by the thermal characteristics of the veneer ceramic. PMID:24786347

  12. Influence of surface treatment on bond strength of veneering ceramics fused to zirconia.

    PubMed

    Tada, Kouki; Sato, Toru; Yoshinari, Masao

    2012-01-01

    In all-ceramic restorations involving a zirconia framework, surface treatment of the zirconia surface is required to enhance bonding strength with the veneering ceramics and thus prevent chipping. The purpose of the present study was to investigate the influence of surface roughness and heat treatment of the zirconia and use of liner porcelain on bond strength between veneering ceramics and a zirconia framework. Debonding/crack-initiation strength (τb) was determined according to ISO 9693. No significant difference was observed among conditions, except with use of a liner under heat treatment, which yielded a τb of 26.0±2.9-28.9±1.7 MPa. Electron probe microanalysis revealed that components of the veneering ceramics remained on the zirconia surface after debonding, suggesting that fractures occur in the veneering ceramics and that improving the strength of the veneering ceramics themselves might increase bond strength. PMID:22447064

  13. 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.

  14. 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.

  15. Dental Sealants

    MedlinePlus

    ... Data & Statistics > Find Data by Topic > Dental Sealants Dental Sealants Main Content Dental sealants are thin plastic coatings that protect the chewing surfaces of children’s back teeth from tooth decay. Overall, the prevalence of sealants ...

  16. 40 CFR 429.30 - Applicability; description of the veneer subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... to waters of the United States and to the introduction of process wastewater pollutants into publicly owned treatment works from any plant which manufactures veneer and does not store or hold raw...

  17. Direct Restorative Treatment of Missing Maxillary Laterals with Composite Laminate Veneer: A Case Report

    PubMed Central

    Bagis, Bora; Aydoğan, Elif; Bagis, Yildirim H.

    2008-01-01

    This clinical report describes a direct composite laminate veneer restoration of the maxillary anterior teeth in one chair time to produce a better esthetic appearance in a patient with diastemata and missing laterals. PMID:19088889

  18. Comparison of edge chipping resistance of PFM and veneered zirconia specimens

    PubMed Central

    Quinn, Janet B.; Sundar, Veeraraghavan; Parry, Edward E.; Quinn, George D.

    2011-01-01

    Objectives To investigate the chipping resistance of veneered zirconia specimens and compare it to the chipping resistance of porcelain fused to metal (PFM) specimens. Methods Veneered zirconia and PFM bar specimens were prepared in clinically relevant thicknesses. The specimen edges were chipped with different magnitude forces, producing chips of various sizes. The range of sizes included small chips that did not penetrate all the way through the veneers to the substrates, and also chips that were very large and reached the zirconia or metal substrates. The relationship between force magnitude and chip size (edge distance) was graphed. The resulting curves were compared for the veneered zirconia and PFM specimens. Knoop hardness vs. force graphs for the veneers and substrates were also obtained. Results The zirconia and PFM veneer chipping data followed a power law (coefficient of determination, R2 > 0.93) as expected from the literature. The curves overlapped within the combined data scatter, indicating similar resistance to chipping. The chips made in both types of specimens detached and did not penetrate into the substrate when they reached the veneer/substrate intersections. The hardness–load curves for the veneers and substrates all exhibited an indentation size effect (ISE) at low loads. The Knoop hardness values with uncertainties of ±one standard deviation at 4 N loads for the metal, zirconia, and the metal and zirconia veneers are: (2.02 ± 0.08, 12.01 ± 0.39, 4.24 ± 0.16 and 4.36 ± 0.02 GPa), respectively, with no statistically significant difference between the veneers (Tukey pairwise comparison at 0.95 family confidence). Significance This work indicates that a similar resistance to chipping might be expected for veneered zirconia and PFM restorations, in spite of the large difference in substrate hardness. Differences in susceptibility to chip spalling were not detected, but the chips in both specimen types detached off the sides in a similar

  19. 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. PMID:27482994

  20. 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

  1. 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

  2. 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

  3. 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.

  4. Critical appraisal: clinical considerations for restoring mandibular incisors with porcelain laminate veneers.

    PubMed

    Walter, Robert D; Raigrodski, Ariel J

    2008-01-01

    Porcelain laminate veneers have been proven to be a successful treatment modality for maxillary incisors in clinical practice and in controlled clinical studies. However, the data in clinical studies on the success of veneers for restoring mandibular incisors are limited. Clinically, the successful restoration of mandibular incisors with porcelain laminate veneers is one of the more challenging procedures in all of esthetic restorative dentistry. Limited coronal dimensions, the small amount of enamel available for bonding (particularly in the cervical areas), materials and techniques for the bonding procedures, and the response of the tooth-veneer complex to forces generated during the incisal loading in both functional as well as parafunctional contacts must be considered as potential sources of success or failure. This Critical Appraisal reviews three recent scientific articles to shed some light on these issues and, as in all research endeavors, leads the reader to identify additional areas of concern that might stimulate further scientific inquiry. The first publication studied predictors for enamel thickness for mandibular incisors. The second examined bonding protocols for exposed dentin and suggested immediate dentin sealing. The third paper addressed fracture behavior of mandibular incisors restored with porcelain laminate veneers in vitro. PMID:18768002

  5. 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

  6. 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

  7. [Assessment of the amount of palladium-silver alloy used for cast posts and veneer crowns].

    PubMed

    Catović, A; Baucić, I

    1988-01-01

    Average amounts of palladium-silver alloy were assessed in a sample of 966 veneer crowns and 667 casted posts. The mean weight values of the samples under study were compared in relation to particular types of anterior teeth. The specimens cast in Auropal SE were weight by the precise balance, Tehtnica, type 6215. Results were analyzed by weight according to the type of the sample under study, and classified according to age, and to the anterior teeth of the upper and lower jaws. On an average, the heaviest posts and veneer crowns were measured on upper canines, whereas the lighest were those on lower incisors. A cast post was found to be by about 40% heavier than a veneer crown on the same tooth. PMID:3076349

  8. Dental Hygienists

    MedlinePlus

    ... anatomy, patient management, and periodontics, which is the study of gum disease. High school students interested in becoming dental hygienists should take courses in biology, chemistry, and math. Most dental hygiene programs also require applicants to have completed at ...

  9. Dental sealants

    MedlinePlus

    ... this page: //medlineplus.gov/ency/patientinstructions/000779.htm Dental sealants To use the sharing features on this ... case a sealant needs to be replaced. How Dental Sealants Are Applied Your dentist applies sealants on ...

  10. 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

  11. 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.

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. Enamel microabrasion for aesthetic management of dental fluorosis.

    PubMed

    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

  17. 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

  18. Complete mouth reconstruction with implant-supported fixed partial dental prostheses fabricated with zirconia frameworks: a 4-year clinical follow-up.

    PubMed

    Puri, Shweta; Parciak, Ewa C; Kattadiyil, Mathew T

    2014-09-01

    Few scientific reports regarding the success of complete mouth partial fixed dental prostheses frameworks fabricated with zirconia are available, especially when dental implants serve as the abutments. A complete mouth reconstruction with zirconia frameworks veneered with feldspathic porcelain is reported involving a 65-year-old white woman who presented with partial edentulism and an unrestorable remaining dentition. After examination, 14 implants were planned (8 in the maxillary arch and 6 in the mandibular arch), and implant-supported zirconia framework screw-retained partial fixed dental prostheses (ISZPFDPs) were fabricated and made in sections for easier retrievability and management. No major complications were encountered during follow-up appointments at 6-month intervals for 4 years. However, minor fractures of the veneering ceramic were noted 4 years after placement. The ISZPFDPs were well accepted by the patient and had a favorable outcome in terms of patient acceptability and success, despite some complications. PMID:24674806

  19. 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.

  20. 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

  1. 46 CFR 32.56-50 - Combustible veneers-T/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... REQUIREMENTS Structural Fire Protection for Tank Ships With a Keel Laying Date On or After January 1, 1975 § 32... veneers on bulkheads, linings, and ceilings within accommodation, service, or control spaces must be 2... spaces, corridors, stairway enclosures, or control spaces must be an approved interior finish material...

  2. Role of core support material in veneer failure of brittle layer structures.

    PubMed

    Hermann, Ilja; Bhowmick, Sanjit; Lawn, Brian R

    2007-07-01

    A study is made of veneer failure by cracking in all-ceramic crown-like layer structures. Model trilayers consisting of a 1 mm thick external glass layer (veneer) joined to a 0.5 mm thick inner stiff and hard ceramic support layer (core) by epoxy bonding or by fusion are fabricated for testing. The resulting bilayers are then glued to a thick compliant polycarbonate slab to simulate a dentin base. The specimens are subjected to cyclic contact (occlusal) loading with spherical indenters in an aqueous environment. Video cameras are used to record the fracture evolution in the transparent glass layer in situ during testing. The dominant failure mode is cone cracking in the glass veneer by traditional outer (Hertzian) cone cracks at higher contact loads and by inner (hydraulically pumped) cone cracks at lower loads. Failure is deemed to occur when one of these cracks reaches the veneer/core interface. The advantages and disadvantages of the alumina and zirconia core materials are discussed in terms of mechanical properties-strength and toughness, as well as stiffness. Consideration is also given to the roles of interface strength and residual thermal expansion mismatch stresses in relation to the different joining methods. PMID:17078086

  3. 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., III; Clark, B. C.; Gellert, Ralf; Golombek, M.P.; Grotzinger, J.P.; Herkenhoff, K. E.; Johson, J.R.; McLennam, S.M.; Morris, R.; 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.

  4. 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

  5. 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. PMID:24158142

  6. 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

  7. 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. PMID:25331825

  8. 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.

  9. Dental radiology.

    PubMed

    Woodward, Tony M

    2009-02-01

    Dental radiology is the core diagnostic modality of veterinary dentistry. Dental radiographs assist in detecting hidden painful pathology, estimating the severity of dental conditions, assessing treatment options, providing intraoperative guidance, and also serve to monitor success of prior treatments. Unfortunately, most professional veterinary training programs provide little or no training in veterinary dentistry in general or dental radiology in particular. Although a technical learning curve does exist, the techniques required for producing diagnostic films are not difficult to master. Regular use of dental x-rays will increase the amount of pathology detected, leading to healthier patients and happier clients who notice a difference in how their pet feels. This article covers equipment and materials needed to produce diagnostic intraoral dental films. A simplified guide for positioning will be presented, including a positioning "cheat sheet" to be placed next to the dental x-ray machine in the operatory. Additionally, digital dental radiograph systems will be described and trends for their future discussed. PMID:19410234

  10. 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…

  11. 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

  12. Composite laminate veneers with a continuous inorganic phase comprising microporous sintered glass fiber networks.

    PubMed

    Ehrnford, L

    1983-10-01

    Veneers were made from sheets consisting of a three-dimensional network of sintered ultrafine glass fibers. The sheets were molded by a vacuum-pressure technique and then impregnated with a liquid resin. Impregnation was performed with a method that enabled the depth of penetration to be monitored. The resin was cured with UV radiation under N2 protection. By the use of TiO2-containing resins the veneer achieved an enamel-like appearance. An in vitro toothbrush dentifrice abrasion test showed a high wear resistance and persisting surface luster. Scanning electron and light microscopy showed fairly smooth and flat light-reflecting glass structures in the surface. PMID:6362318

  13. Indirect porcelain veneers in periodontally compromised teeth. The hybrid technique: a case report.

    PubMed

    Garcia-Baeza, David; Saavedra, Carlos; Garcia-Adámez, Ramón

    2015-01-01

    The loss of periodontal structure causes an esthetic problem for many patients, especially when the esthetic zone is compromised. Among the various types of solutions is the use of composite resins. While this procedure is not aggressive towards tooth structure, it does require the clinician to have a precise technique, and demands strict longterm maintenance. 1 Another way of treating the compromised teeth is with porcelain veneers. This procedure is especially difficult, however, if carried out on periodontal teeth, as it requires preparation along the roots. 2 The intention of the hybrid technique described in this article is to combine both of these procedures in order to obtain a less aggressive treatment with precise management of the soft tissue and an adequate esthetic outcome. The hybrid technique consists of enlarging the root portion of the teeth with composite resin to obtain a less aggressive tooth preparation, and thereafter placing porcelain veneers. PMID:26171444

  14. Furnace veneering systems of special design help achieve energy reduction goals at Armco

    SciTech Connect

    Caspersen, L.J.

    1982-12-01

    A steel company conserves energy by veneering reheat furnaces with a ceramic fiber modular system. The furnace lining system incorporates several grades of veneering materials (modules, cements, coatings) whose application is matched to the exact conditions in the furnace. Zoned linings utilize a combination of grades of alumina-silica modules to achieve thermally efficient yet durable performance. High temperature cements exhibit good tackiness, easy module penetration and high strength retention after firing. A protective coating is sprayed in a thin layer over the modules and can be easily reapplied at a later date should it be necessary. Benefits include greater thermal control (temperature responsiveness and heating uniformity), less over-firing, less fuel use, and less heat loss. Fuel efficiency is increased by 20 to 50%.

  15. 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

  16. 46 CFR 32.56-50 - Combustible veneers-T/ALL.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Combustible veneers-T/ALL. 32.56-50 Section 32.56-50 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS SPECIAL EQUIPMENT, MACHINERY, AND HULL REQUIREMENTS Structural Fire Protection for Tank Ships With a Keel Laying Date On or After January 1, 1975 § 32.56-50 Combustible veneers—T/ALL....

  17. 46 CFR 32.56-50 - Combustible veneers-T/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Combustible veneers-T/ALL. 32.56-50 Section 32.56-50 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS SPECIAL EQUIPMENT, MACHINERY, AND HULL REQUIREMENTS Structural Fire Protection for Tank Ships With a Keel Laying Date On or After January 1, 1975 § 32.56-50 Combustible veneers—T/ALL....

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

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Combustible veneers-T/ALL. 32.56-50 Section 32.56-50 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS SPECIAL EQUIPMENT, MACHINERY, AND HULL REQUIREMENTS Structural Fire Protection for Tank Ships With a Keel Laying Date On or After January 1, 1975 § 32.56-50 Combustible veneers—T/ALL....

  19. Comparison of shear bond strength of two veneering ceramics to zirconia

    PubMed Central

    Rismanchian, Mansour; Shafiei, Soufia; Askari, Navid; Khodaeian, Niloufar

    2012-01-01

    Background: Chip-off fracture of veneering porcelain has been described as the most frequent reason for the failure of zirconia-based fixed partial dentures. The purpose of this study was to evaluate the shear bond strength (SBS) of two commercial zirconia core ceramics to their corresponding veneering ceramics. Materials and Methods: Zirconia disks with 7-mm diameter and 3-mm height were prepared (Cercon and Biodenta systems) and veneered with recommended layering ceramics (Cercon ceram and 2 in 1 ceramic, respectively) (n = 10). The disks were polished with diamond paste and airborne-particle abraded before layering. The specimens were mounted in a T-shaped metal holder using autopolymerized acrylic resin and stored in 37°C distilled water for one week, after which they were subjected to thermal cycling. SBS of zirconia core to veneering ceramic was measured using a universal testing machine and failure modes were determined microscopically. Data were analyzed using t test (α < 0.05). Results: Mean (±SD) SBS values were 27.19(±3.43) and 28.22(±4.08) MPa for Cercon and Biodenta systems, respectively, with no significant difference. Biodenta system showed more adhesive failure compared to more combined (adhesive and cohesive) failures in Cercon system. Conclusion: Within the limitations of this study it can be concluded that SBS of Biodenta and Cercon specimens were nearly the same, but the fracture mode of these two systems were different. Since Biodenta fracture pattern was predominantly adhesive, it seems that maybe Biodenta porcelain was stronger than Cercon porcelain where as its adhesive bond was weaker. PMID:23559931

  20. 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.

  1. 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. PMID:12488858

  2. 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.

  3. Microspectral analysis with laser in microleakage evaluation between infrastructure and veneer materials in fixed partial dentures

    NASA Astrophysics Data System (ADS)

    Negrutiu, Meda L.; Sinescu, Cosmin; Draganescu, Gheorghe; Todea, Carmen; Dodenciu, Dorin; Rominu, Roxana

    2008-02-01

    The microleakage at the interface between the metal infrastructure and the veneering part of the fixed partial dentures are a common problem of aesthetic dentistry. It is possible to use the method of laser microspectral analysis for investigations of microleakage at the metal-veneering material interfaces in fixed partial prostheses. The laser microspectral analysis device LMA-10 (Carl Zeiss, Jena) was used equipped with a diffraction spectrometer PGS-2 (Carl Zeiss, Jena). Different fixed partial dentures were used to determine the microleakage between the metal infrastructure and the veneering material. The distribution of chemical elements at interface infiltration was investigated, making a series of craters and establishing the spectra of the vapours emitted from the craters. Data was gathered in various tables of chemical elements showing the quality and the quantity of microleakage. The laser microspectral analysis is a punctual method of analysis, which allows to investigate small quantities of materials of around 0.1 μg. This method allows to establish the content of atoms and molecules and to perform semi-quantitative and quantitative analysis. By this method it is possible to establish trace elements, i. e. with concentration of ppm (parts per million).

  4. Effects of coloring procedures on zirconia/veneer ceramics bond strength

    PubMed Central

    Özat, Pelin; Eroğlu, Erdal

    2014-01-01

    PURPOSE The most common failure seen in restorations with a zirconia core is total or layered delamination of the ceramic veneer. In the present study, the shear bond strengths between veneering ceramics and colored zirconia oxide core materials were evaluated. MATERIALS AND METHODS Zirconia discs (15 × 12 × 1.6 mm) were divided into 11 groups of 12 discs each. Groups were colored according to the Vita Classic scale: A3, B1, C4, D2, and D4. Each group was treated with the recommended shading time for 3 s, or with prolonged shading for 60 s, except for the control group. Samples were veneered with 3 mm thick and 3.5 mm in diameter translucent ceramic and subjected to shear test in a universal testing machine with a crosshead speed of 1 mm/min. One-way analysis of variance (ANOVA) and Tukey's HSD tests were used for comparisons of the groups having the same shading times. A paired t-test was used for groups of the same color (3 s/60 s). RESULTS Among the 11 groups investigated C4 (3 s) had the highest bond strength with a value of 36.40 MPa, while A3 (3 s) showed the lowest bond strength with a value of 29.47 MPa. CONCLUSION Coloring procedures can affect zirconia/ceramic bond strength. However, the results also showed that bond strengths of all the investigated groups were clinically acceptable. PMID:25551004

  5. Effect of surface treatment and liner material on the adhesion between veneering ceramic and zirconia.

    PubMed

    Yoon, Hyung-in; Yeo, In-sung; Yi, Yang-jin; Kim, Sung-hun; Lee, Jai-bong; Han, Jung-suk

    2014-12-01

    Fully sintered zirconia blocks, each with one polished surface, were treated with one of the followings: 1) no treatment, 2) airborne-particle abrasion with 50μm alumina, and 3) airborne-particle abrasion with 125μm alumina. Before veneering with glass ceramic, either liner Α or liner B were applied on the treated surfaces. All veneered blocks were subjected to shear force in a universal testing machine. For the groups with liner A, irrespective of the particle size, air abrasion on Y-TZP surfaces provided greater bond strength than polishing. Application of liner B on an abraded zirconia surface yielded no significant influence on the adhesion. In addition, specimens with liner A showed higher bond strength than those with liner B, if applied on roughened surfaces. Fractured surfaces were observed as mixed patterns in all groups. For the liner A, surface treatment was helpful in bonding with veneering ceramic, while it was ineffective for the liner B. PMID:25282467

  6. Activation of wood surfaces for glue bonds by mechanical pre-treatment and its effects on some properties of veneer surfaces and plywood panels

    NASA Astrophysics Data System (ADS)

    Aydin, İsmail

    2004-06-01

    Some chemical pre-treatments with chemical reagents are widely applied to wood surfaces in order to improve bonding ability, wettability and reactivate wood surfaces for glue-wood bonds. Besides these chemical treatments, some mechanical pre-treatments such as sanding and planing can be applied to get a fresh surface which eliminates bonding problems and improves glue bonding of wood. In this study, 2 mm thick rotary cut veneers obtained from steamed beech ( Fagus orientalis) logs were used as material. Both air-drying and oven-drying methods were used for drying veneer. After drying, the surfaces of some veneers were sanded with 100 and 180 grit sandpapers. Three-layer-plywood panels were produced from sanded and non-sanded veneers by using urea formaldehyde and phenol formaldehyde glue resins to evaluate the effects of sanding some mechanical properties of plywood. Changes in pH, surface roughness and adhesive wettability of veneers were evaluated. Wettability of veneers was assessed with contact angle measurements according to the sessile drop method. Both veneer and plywood properties investigated in this study improved clearly after the sanding process. Shear and bending strength values of plywood panels manufactured from sanded and non-sanded veneers were vary depending on glue types and veneer drying methods.

  7. Dental Fluorosis

    MedlinePlus

    ... when children regularly consume fluoride during the teeth-forming years, age 8 and younger. Most dental fluorosis ... over a long period when the teeth are forming under the gums. Only children aged 8 years ...

  8. Dental Implants

    MedlinePlus Videos and Cool Tools

    ... facts so you can make an informed decision as to whether dental implants are right for your ... the jaw bone. It’s obviously not the same as the original connection , but functions just the same. ...

  9. Dental Caries (Tooth Decay)

    MedlinePlus

    ... Find Data by Topic > Dental Caries (Tooth Decay) Dental Caries (Tooth Decay) Main Content Dental caries (tooth decay) remains the most prevalent chronic ... important source of information on oral health and dental care in the United States since the early ...

  10. 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

  11. Spectrophotometric evaluation of the influence of different backgrounds on the color of glass-infiltrated ceramic veneers.

    PubMed

    Charisis, Dimitrios; Koutayas, Spiridon-Oumvertos; Kamposiora, Photini; Doukoudakis, Asterios

    2006-08-01

    The purpose of this spectrophotometric study was to evaluate the influence of different color backgrounds on Vita In-Ceram (Vident) glass-infiltrated ceramic veneers. A total of 50 color background disks were fabricated from Vitadur Alpha 2M2 (n=30) and 5M1 (n=20) dentin porcelain (Vi-dent). Ceramic veneer disks were fabricated from In-Ceram Spinell (n=20) or In-Ceram Alumina (n=20) glass-infiltrated core veneered using Vitadur Alpha 2M2 dentin porcelain. In addition, 10 ceramic veneer disks were fabricated from feldspathic dentin porcelain Vitadur Alpha 2M2. The ceramic veneer specimens were bonded onto the color background specimens using dual-curing luting composite cement, creating the following groups (each n=10): S2M2 (Spinell/2M2), S5M1 (Spinell/5M1), A2M2 (Alumina/2M2), A5M1 (Alumina/5M1), and control (Vitadur Alpha/2M2). L*a*b* color coordinates were measured five times for each specimen using a Vita Easyshade (Vident) spectrophotometer. Mean color differences (deltaE) between each study group and the control group were: 3.79 for S2M2; 7.24 for S5M1; 5.86 for A2M2, and 7.32 for A5M1. Two-way ANOVA showed statistically significant differences in deltaE between all groups. However, a t test revealed that the statistically significant differences only existed between groups S2M2/S5M1, A2M2/A5M1, and S2M2/A2M2. The results suggest that vacuum infiltration with a translucent glass provides the Spinell and Alumina ceramic veneers with increased semi-translucency, which makes them highly influenced by discolored backgrounds. In-Ceram Spinell glass-infiltrated ceramic veneers could be considered as an alternative to conventional feldspathic veneers for the restoration of nondiscolored teeth. Although Spinell and Alumina ceramic veneers could enhance the final color establishment of discolored teeth, the results would not be clinically acceptable. PMID:19655483

  12. 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

  13. 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. PMID:27007354

  14. Resin-bonded fixed dental prosthesis with a modified treatment surface in a zirconia framework: a case report.

    PubMed

    Viana, Pedro Couto; Portugal, Jaime; Kovacs, Zsolt; Lopes, Ivo; Correia, André

    2016-01-01

    Although resin-bonded fixed dental prostheses (RBFDPs) were developed almost 40 years ago, their implementation in clinical practice did not achieve success due to biomechanical failures of the restorative materials. Nowadays, the evolution of ceramic materials and bonding procedures has allowed for the revival of the dental prosthesis. Zirconia is the dental ceramic with the highest flexural strength under compression. However, there are still some concerns regarding the bonding strength of zirconia to enamel that require further research. In this article, through the presentation of three clinical cases, the authors show how modifying the surface of zirconia frameworks by applying a feldspathic veneering on the retainer's buccal surface allows for a bonding procedure to dental structures. The goal of this treatment method is to simultaneously improve structural strength, esthetic integration, and bonding optimization to enamel. In a 3-year prospective evaluation, this framework modification shows promising results, with a survival rate of 100% and no biological or mechanical complications. PMID:27433551

  15. 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.

  16. 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

  17. 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. PMID:25344891

  18. 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

  19. 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

  20. [Effect of erosion on strength of dental infiltrated Al2O3 ceramics].

    PubMed

    Xiong, Fang; Yu, Haiyang A; Liao, Yunmao; Zhu, Zhimin; Zhou, Zhongrong; Zhu, Minhao

    2005-12-01

    The objective of the research is to investigate the elements of routine sandblast technique on the evolution of bending strength of dental infiltrated Al2O3 ceramics and the underlying erosion mechanism. The plane specimens of an infiltrated ceramic were manufactured, polished and then tested under the modified pen-like sandblasting apparatus (90 degrees erosive angle and 10 mm sandblasting distance), with different grit sizes, working pressure and disposing time. Half of samples were selected randomly and sintered subsequently with Vitadur alpha veneering porcelain. Before and after sintering, the three-point-bending strengths was measured, and the surfaces of dental porcelain were observed with SEM and LCSM. The bending strength of ceramics decreased significantly after sandblast as compared with that of empty control group. After the procedure of sintering the veneering porcelain, the descending evolution of bending strength slowed down. Under the present manufacturing conditions, grit size effect is prominent among those correlative elements of sand grit size, working pressure and disposing time. And fatigue cracking characterizes the mechanism of erosion of dental infiltrated Al2O3 ceramics. PMID:16422096

  1. Rehabilitation of the dominance of maxillary central incisors with refractory porcelain veneers requiring minimal tooth preparation.

    PubMed

    da Cunha, Leonardo Fernandes; Gonzaga, Carla Castiglia; Saab, Rafaella; Mushashe, Amanda Mahammad; Correr, Gisele Maria

    2015-01-01

    Central dominance is an important element of an esthetic smile. Color, form, and size have been suggested as tools for assessing the dominance of maxillary teeth. A spectrophotometer can be used to determine the value, hue, and chroma. Correct sizing of restorations according to the central incisor dominance principle improves not only esthetics but also aspects of occlusion, such as anterior guidance. Refractory porcelain systems can effectively restore the color, shape, emergence profile, and incisal translucency. This report illustrates the esthetic and occlusal rehabilitation of the dominance of maxillary central incisors using fabricated minimal thickness refractory porcelain veneers. PMID:26345102

  2. 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

  3. Dental Assistant.

    ERIC Educational Resources Information Center

    Michigan State Univ., East Lansing. Coll. of Agriculture and Natural Resources Education Inst.

    This curriculum guide, developed for use in dental assistant education programs in Michigan, describes a task-based curriculum that can help a teacher to develop a classroom management system where students learn by doing. It is based on task analysis and reflects the skills, knowledge, and attitudes that employers expect entry-level dental…

  4. Dental crowns

    MedlinePlus

    ... cover a tooth Replace a misshapen tooth or dental implant Correct a misaligned tooth Talk to your dentist ... the tooth pulled and replaced with a tooth implant. Your crown could chip or crack: If you grind your teeth or clench your jaw, you may need to ...

  5. What I wish I'd learned at dental school.

    PubMed

    Oliver, G R; Lynch, C D; Chadwick, B L; Santini, A; Wilson, N H F

    2016-08-26

    Background Much concern appears to exist as to the scope and content of contemporary dental school programmes, with the oft-cited criticism being made that dental graduates are 'no longer as good as they used to be'.Aim The aim of this project was to survey the views of dentists - both new graduates and more established practitioners - on aspects of their own dental school training they felt had been deficient as well as commenting on what aspects of dental school education they would like to see improved/enhanced in current times.Methods An invitation to complete an Internet-based questionnaire was emailed to the Fellows and Members of the Faculty of General Dental Practice (UK). Topics in the questionnaire included the respondent's own dental education history, how well they felt their dental school training had covered certain clinical and non-clinical topics; and their opinions on areas they felt should be included in contemporary dental school programmes.Results Six hundred and forty-nine responses were received from 3,348 emailed invitations (response rate = 19.4%). Sixty-one percent (395) of respondents were qualified for 10 years or more. Among clinical skills and techniques, a majority of respondents reported they felt they had not had sufficient teaching/training in dental school in surgical endodontics (76%), conscious sedation (72%), root surface debridement (71%), fixed orthodontic appliances (68%), porcelain veneers (63%), implants (56%) and posterior composites (53%). If designing a new dental school programme, the most common topics respondents would seek to include/increase were business and practice management (21%), communication skills (including patient management and leadership skills) (10%), and increased clinical time and experience (8%).Conclusions The findings of this project are of interest and relevance to those working with student dentists and young dental practitioners. A greater emphasis is needed on the teaching of certain non

  6. 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,…

  7. Reliability of reduced-thickness and thinly veneered lithium disilicate crowns.

    PubMed

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

    2012-03-01

    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

  8. Compatibility of Ce-TZP/Al2O3 nanocomposite frameworks and veneering porcelains.

    PubMed

    Terui, Yuichi; Sato, Kotaro; Goto, Daisuke; Hotta, Yasuhiro; Tamaki, Yukimichi; Miyazaki, Takashi

    2013-01-01

    The aim of this study was to examine the compatibility of Ce-TZP/Al2O3 nanocomposite (CTA) frameworks and veneering porcelains using the Schwickerath crack initiation test and clarify the effects on debonding/crack initiation strength (DIS) of both surface pretreatment (include heat treatment) of the frameworks, type of veneering porcelain varying the coefficient of thermal expansion (CTE), and surface roughness of the frameworks. The surfaces of Ce-TZP/Al2O3 plates were mechanically treated and followed by post-heat treatment. The liner and body porcelains were built up and fired according to the manufacturer's instructions. Surface analyses of the fractured plates showed compatibility with liner porcelains. Since no statistically difference in the DIS was found amongst the different surface treatments, post-heat treatments don't be mandatory. Whereas, since differences in DIS were found when different porcelains with different CTE were used, we concluded the matching of CTE of the porcelain with that of Ce-TZP/Al2O3 was important for successful all-ceramic restorations using Ce-TZP/Al2O3 frameworks. PMID:24088843

  9. 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. PMID:26454136

  10. 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.

  11. 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

  12. 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

  13. Dental x-rays

    MedlinePlus

    ... or impacted teeth The presence and extent of dental caries (cavities) Bone damage (such as from periodontitis ) Abscessed ... Dental x-rays can reveal dental cavities (tooth decay) before they ... take yearly bitewings for the early development of cavities.

  14. Comparative study between laser sintering and casting for retention of resin composite veneers to cobalt-chromium alloy.

    PubMed

    Muratomi, Ryuta; Kamada, Kohji; Taira, Yohsuke; Higuchi, Shizuo; Watanabe, Ikuya; Sawase, Takashi

    2013-01-01

    The purpose of this study was to evaluate and compare the bond strengths between resin composite veneer and laser-sintered cobalt-chromium (Co-Cr) alloy with and without retention devices (Laser-R and Laser-N respectively). Cast Co-Cr alloy with and without retention devices (Cast-R and Cast-N respectively) were also prepared for fabrication technique comparison. Disk-shaped Co-Cr alloy specimens were air-abraded with alumina and veneered with a veneering system, Estenia C&B (ES) or Ceramage (CE). After 20,000 thermocycles, tensile testing was performed. Data were analyzed by ANOVA and multiple comparison test. When no retention devices were present, no significant differences were observed between Laser-N/ES and Cast-N/ES, or between Laser- N/CE and Cast-N/CE, but ES exhibited significantly higher bond strength than CE. With retention devices, Laser-R/ES, Cast- R/ES and Laser-R/CE showed no significant differences, and their retention strengths were significantly higher than that of Cast- R/CE. Compared to cast Co-Cr alloy, laser-sintered Co-Cr alloy with retention devices provided better retention durability for resin composite-veneered prostheses. PMID:24240892

  15. 75 FR 28661 - Ceda-Pine Veneer, Inc., a Subsidiary of Excaliber, Inc., Sandpoint, ID; Notice of Negative...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-21

    ... FR 7034). Pursuant to 29 CFR 90.18(c,) reconsideration may be granted under the following... determination regarding eligibility to apply for Trade Adjustment Assistance (TAA), applicable to workers and... negative determination of the TAA petition filed on behalf of workers at Ceda-Pine Veneer, Inc.,...

  16. 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.

  17. Dental Fear among Medical and Dental Undergraduates

    PubMed Central

    Hakim, H.; Razak, I. A.

    2014-01-01

    Objective. To assess the prevalence and level of dental fear among health related undergraduates and to identify factors causing such fear using Kleinknecht's Dental Fear Survey (DFS) questionnaire. Methods. Kleinknecht's DFS questionnaire was used to assess dental fear and anxiety among the entire enrollment of the medical and dental undergraduates' of the University of Malaya. Results. Overall response rate was 82.2%. Dental students reported higher prevalence of dental fear (96.0% versus 90.4%). However, most of the fear encountered among dental students was in the low fear category as compared to their medical counterpart (69.2 versus 51.2%). Significantly more medical students cancelled dental appointment due to fear compared to dental students (P = 0.004). “Heart beats faster” and “muscle being tensed” were the top two physiological responses experienced by the respondents. “Drill” and “anesthetic needle” were the most fear provoking objects among respondents of both faculties. Conclusion. Dental fear and anxiety are a common problem encountered among medical and dental undergraduates who represent future health care professionals. Also, high level of dental fear and anxiety leads to the avoidance of the dental services. PMID:25386615

  18. 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

  19. Occupational Health and Safety Issues in Ontario Sawmills and Veneer/Plywood Plants: A Pilot Study

    PubMed Central

    Verma, Dave K.; Demers, Cecil; Shaw, Don; Verma, Paul; Kurtz, Lawrence; Finkelstein, Murray; des Tombe, Karen; Welton, Tom

    2010-01-01

    A pilot study was conducted within the Ontario sawmill and veneer/plywood manufacturing industry. Information was collected by postal questionnaire and observational walk-through surveys. Industrial hygiene walk-through surveys were conducted at 22 work sites, and measurements for wood dust, noise, and bioaerosol were taken. The aim of the study was to obtain data on the current status regarding health and safety characteristics and an estimate of wood dust, noise, and bioaerosol exposures. The occupational exposure to wood dust and noise are similar to what has been reported in this industry in Canada and elsewhere. Airborne wood dust concentration ranged between 0.001 mg/m3 and 4.87 mg/m3 as total dust and noise exposure ranged between 55 and 117 dB(A). The study indicates the need for a more comprehensive industry-wide study of wood dust, noise, and bioaersols. PMID:21253473

  20. Occupational health and safety issues in Ontario sawmills and veneer/plywood plants: a pilot study.

    PubMed

    Verma, Dave K; Demers, Cecil; Shaw, Don; Verma, Paul; Kurtz, Lawrence; Finkelstein, Murray; des Tombe, Karen; Welton, Tom

    2010-01-01

    A pilot study was conducted within the Ontario sawmill and veneer/plywood manufacturing industry. Information was collected by postal questionnaire and observational walk-through surveys. Industrial hygiene walk-through surveys were conducted at 22 work sites, and measurements for wood dust, noise, and bioaerosol were taken. The aim of the study was to obtain data on the current status regarding health and safety characteristics and an estimate of wood dust, noise, and bioaerosol exposures. The occupational exposure to wood dust and noise are similar to what has been reported in this industry in Canada and elsewhere. Airborne wood dust concentration ranged between 0.001 mg/m³ and 4.87 mg/m³ as total dust and noise exposure ranged between 55 and 117 dB(A). The study indicates the need for a more comprehensive industry-wide study of wood dust, noise, and bioaersols. PMID:21253473

  1. 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

  2. Clinical performance of novel-design porcelain veneers for the recovery of coronal volume and length.

    PubMed

    Magne, P; Perroud, R; Hodges, J S; Belser, U C

    2000-10-01

    The present study evaluated the clinical performance of bonded porcelain veneers (PV) restoring substantial coronal volume and length in the anterior dentition. Forty-eight PVs were placed in 16 patients, with systematic coverage and reconstitution of the incisal edge, including well-defined anterior guidance. A standardized protocol comprising diagnostic steps that integrate additive waxups and acrylic mockups was used. PVs were fabricated using feldspathic and low-fusing porcelains in a refractory die technique. Incisal overlaps featured freestanding porcelain spans ranging from 1.5 to 5.5 mm. After a mean clinical service of 4.5 years, 13 clinical parameters for each tooth and 4 parameters that applied to persons were recorded. Permutation tests evaluated the effects of margin location, incisal edge span of porcelain, overbite, opposing contact location, and restoration age on ceramic failure and clinical marginal adaptation and seal. At recall, 100% of the veneers were satisfactory with minor interventions. The effect of slight marginal defects and porcelain cracking was negligible. Biologic, periodontal, and esthetic parameters showed excellent results, which were supported by 100% patient-reported satisfaction. All patients felt comfortable with the newly defined anterior guidance. Aging was negligible, and there were no significant effects of margin location (P > 0.08), incisal edge span of the ceramic, or overbite (P > 0.22) on ceramic failure and marginal performance. Minor alterations of the palatal margin, however, tended to be more frequent compared to facial locations, and were found especially when the opposing tooth contact in centric occlusion was located on the palatal margin (P = 0.028). Bonded ceramic restorations represent a reliable, effective procedure to restore extensive coronal volume and length in the anterior dentition. PMID:11203582

  3. Infant dental care (image)

    MedlinePlus

    ... child to bed with a bottle of milk, juice, or sugar water. As the child grows, establishing proper dental hygiene will promote healthy teeth and gums which are essential to overall good health. Poor dental development, dental disease, and dental trauma ...

  4. 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. PMID:23077720

  5. 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

  6. 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. PMID:27424337

  7. 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. PMID:26126345

  8. Dental stem cell patents.

    PubMed

    Morsczeck, Christian; Frerich, Bernhard; Driemel, Oliver

    2009-01-01

    A complex human tissue harbors stem cells that are responsible for its maintenance or repair. These stem cells have been isolated also from dental tissues such as the periodontal ligament, dental papilla or dental follicle and they may offer novel applications in dentistry. This following review summarizes patents about dental stem cells for dental tissue engineering and considers their value for regenerative dentistry. PMID:19149737

  9. 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

  10. Dental hyponatraemia.

    PubMed

    Simpson, R M

    2011-08-01

    A 14-year-old girl developed dental pain and was treated for acute infected pulpitis of her right upper lateral incisor with drilling and filling. The pain continued and was helped by analgesia, sucking ice cubes and drinking cold water. Forty-eight hours later, she became confused and disoriented. She started to vomit and complained of headache. Investigations revealed hyponatraemia with normal serum potassium levels and initially normal urinary sodium excretion. Over the next 24 hours, she passed 5.45 L of urine and her serum sodium rose from 125 to 143 mmol/L. Self-induced water intoxication has been described during drinking games and initiation ceremonies, but this would appear to an unusual cause. Conservative management proved successful in allowing this girl to recover without sequelae. PMID:21873727

  11. 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. PMID:23868263

  12. Effect of intermediate fiber layer on the fracture load and failure mode of maxillary incisors restored with laminate veneers.

    PubMed

    Turkaslan, Suha; Tezvergil-Mutluay, Arzu; Bagis, Bora; Shinya, Akikazu; Vallittu, Pekka K; Lassila, Lippo V

    2008-01-01

    This study evaluated the fracture load and failure mode of various veneer materials cemented with or without the addition of a fiber-reinforced composite (FRC) layer at the adhesive interface. Sixty intact incisors were randomly divided into three groups. Group 1 was fabricated with the heat-press technique (IPS Empress 2); Group 2 with the copy milling technique (ZirkonZahn); and Group 3 with the direct or indirect composite technique (Z250)--and specimens were cemented either with or without FRC at the adhesive interface. The specimens were thermocycled and tested with a universal testing machine. No significant differences in fracture load (p>0.05) were found among the various veneer materials. The addition of FRC at the adhesive layer did not lead to significant differences in the fracture load (p>0.05) but resulted in differences in the failure mode. Laminate veneers made of composite, zirconia, and Empress 2 showed comparable mean fracture loads. However, the use of FRC at the interface changed their failure modes. PMID:18309613

  13. Achievable Convergence Angle and the Effect of Preparation Design on the Clinical Outcome of Full Veneer Crowns in Dogs

    PubMed Central

    Soukup, Jason W.; Snyder, Christopher J.; Karls, Tina L.; Riehl, Jessica

    2012-01-01

    Summary It is widely accepted that the convergence angle of a full veneer crown preparation should be as close to parallel as possible to attain adequate retention/resistance. The shape of the dog’s canine tooth limits the veterinary dentists’ ability to achieve the recommended convergence angle. However, the clinically achievable convergence angle of the canine tooth in dogs has not been evaluated. In addition, the convergence angle and other physical properties of a preparation, such as height and base diameter, have been shown to affect the retention/resistance of full veneer crowns, in vitro. This effect has not been evaluated clinically in the dog. Physical properties of 32 stone dies from full veneer crowns of canine teeth were studied to evaluate the clinically achievable convergence angle and the potential effect physical properties of the preparation had on the clinical outcome of the restoration. The clinically achievable convergence angle was much higher than the current recommendation. There was an association, albeit not statistically significant, between physical properties of a preparation (convergence angle, height, base diameter) and the clinical outcome of the restoration. PMID:21916370

  14. 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.

  15. [Dental records and responsibility].

    PubMed

    Brands, W G

    2006-03-01

    Dental records are more than a small part of the bookkeeping. In most dental practises, keeping records is the task of a dental assistant. In civil court, the dentist is in most countries liable for the mistakes of his employees. In disciplinary court however there may be doubt whether the dentist is responsible for the mistakes of his assistant. Contrary to their American colleagues, Dutch dental assistants and dental hygienists cannot be summoned before a disciplinary court. As these para-medics perform more and more dental treatment, independently or after delegation, they should be assigned there own disciplinary responsibility. PMID:16566401

  16. 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

  17. 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…

  18. Dental x-rays

    MedlinePlus

    X-ray - teeth; Radiograph - dental; Bitewings; Periapical film; Panoramic film ... dentist's office. There are many types of dental x-rays. Some are: Bitewing Periapical Palatal (also called occlusal) ...

  19. Dental education in Mexico.

    PubMed

    Masuoka, David; Komabayashi, Takashi; Reyes-Vela, Enrique

    2014-06-01

    The aim of this article is to provide information about dental education in Mexico, including its history, the dental school system, curriculum and dental licensure. In 1977, there were only 59 Mexican dental schools; however, there were 83 schools registered in the last official national count in 2007. Forty-one dental schools are public, and the other 42 are private. Every year the number of private dental schools increases. Admission to dental schools in Mexico requires a high school diploma. All classes are conducted in Spanish. To obtain licensure in Mexico, dental students must complete a 3 to 5-year program plus a year of community service. No formal nationwide standard clinical/didactic curriculum exists in Mexico. There are approximately 153,000 dentists in Mexico, a number that increases each year. The dentist-patient ratio is approximately 1:700. However, the high percentage of inactive licensed dentists in Mexico points to a serious problem. PMID:24984634

  20. Dental education in Malaysia.

    PubMed

    Komabayashi, Takashi; Razak, Abdul Aziz Abdul; Bird, William F

    2007-12-01

    There was only one dental school in Malaysia until 1997 but five new schools have been established since 1998. This review provides information about dental education in Malaysia including; the history of dental education, the current dental school system and curriculum, and dental licensure. There are four public and two private dental schools in Malaysia. High school graduates are required to take the nationwide matriculation entrance examination or the Higher School Certificate (HSC) to apply for a dental degree programme. A five-year dental programme leads to the BDS or the DDS degree. National or state examinations are not required to practise dentistry. Currently, there are approximately 2,500 dentists, with a ratio of 1 dentist for every 10,000 people. PMID:18265775

  1. American Dental Education Association

    MedlinePlus

    ... work hard to help your students fulfill their dreams, and play a crucial... Learn more Dental School ... Terms of Use | Website Feedback | Website Help ©2016 American Dental Education Association® (ADEA), 655 K Street, NW, ...

  2. Effect of veneering material on the deformation suffered by implant-supported fixed prosthesis framework

    PubMed Central

    GRANDO, Antônio Francisco; REZENDE, Carlos Eduardo Edwards; SOUSA, Edson Antônio Capello; RUBO, José Henrique

    2014-01-01

    Knowing how stresses are dissipated on the fixed implant-supported complex allows adequate treatment planning and better choice of the materials used for prosthesis fabrication. Objectives The aim of this study was to evaluate the deformation suffered by cantilevered implant-supported fixed prostheses frameworks cast in silver-palladium alloy and coated with two occlusal veneering materials: acrylic resin or porcelain. Material and Methods Two strain gauges were bonded to the inferior surface of the silver-palladium framework and two other were bonded to the occlusal surface of the prosthesis framework covered with ceramic and acrylic resin on each of its two halves. The framework was fixed to a metallic master model and a 35.2 N compression force was applied to the cantilever at 10, 15 and 20 mm from the most distal implant. The measurements of deformation by compression and tension were obtained. The statistical 2-way ANOVA test was used for individual analysis of the experiment variables and the Tukey test was used for the interrelation between all the variables (material and distance of force application). Results The results showed that both variables had influence on the studied factors (deformation by compression and tension). Conclusion The ceramic coating provided greater rigidity to the assembly and therefore less distortion compared with the uncoated framework and with the resin-coated framework. The cantilever arm length also influenced the prosthesis rigidity, causing higher deformation the farther the load was applied from the last implant. PMID:25025562

  3. 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…

  4. 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…

  5. 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…

  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. 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. PMID:25885796

  8. Description and Documentation of the Dental School Dental Delivery System.

    ERIC Educational Resources Information Center

    Chase, Rosen and Wallace, Inc., Alexandria, VA.

    A study was undertaken to describe and document the dental school dental delivery system using an integrated systems approach. In late 1976 and early 1977, a team of systems analysts and dental consultants visited three dental schools to observe the delivery of dental services and patient flow and to interview administrative staff and faculty.…

  9. 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

  10. 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.

  11. Platinum partitioning between metal and silicate melts: Core formation, late veneer and the nanonuggets issue

    NASA Astrophysics Data System (ADS)

    Médard, Etienne; Schmidt, Max W.; Wälle, Markus; Keller, Nicole S.; Günther, Detlef

    2015-08-01

    High-pressure, high-temperature experiments have been performed at ∼1.2 GPa and 1360-2100 °C to investigate the partitioning of Pt between a silicate melt and a metallic melt. Our experiments indicate that nanonuggets encountered in previous experiments are experimental artifacts, formed at high temperature by oversaturation caused by high oxygen fugacity during the initial stages of an experiment. Experiments at high-acceleration using a centrifuging piston-cylinder show that nanonuggets can be removed by gravity during the experiment. Formation of nanonuggets can also be avoided by using initially reduced starting materials. The presence of iron is also a key element in reducing the formation of nanonuggets. Our nanonugget-free data are broadly consistent with previous nanonuggets-filtered data, and suggest that Pt partitioning becomes independent of oxygen fugacity below an oxygen fugacity of at least IW+2. Pt is thus possibly dissolved as a neutral species (or even an anionic species) at low fO2, instead of the more common Pt2+ species present at higher fO2. Due to low concentration, the nature of this species cannot be determined, but atomic Pt or Pt- are possible options. Under core-formation conditions, Pt partitioning between metal and silicate is mostly independent of oxygen fugacity, silicate melt composition, and pressure. Partition coefficient during core formation can be expressed by the following equation: log DPtMmetal/silicate = 1.0348 + 14698 / T (in weight units). Calculations indicate that the Pt content (and by extension the Highly Siderophile Elements content) of the Earth's mantle cannot be explained by equilibrium partitioning during core formation, requiring further addition of HSE to the mantle. The mass of this late veneer is approximately 0.4% of the total mass of the Earth (or 0.6% of the mass of the mantle).

  12. 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

  13. SEM evaluation of human gingival fibroblasts growth onto CAD/CAM zirconia and veneering ceramic for zirconia

    PubMed Central

    Zizzari, Vincenzo; Borelli, Bruna; De Colli, Marianna; Tumedei, Margherita; Di Iorio, Donato; Zara, Susi; Sorrentino, Roberto; Cataldi, Amelia; Gherlone, Enrico Felice; Zarone, Fernando; Tetè, Stefano

    2013-01-01

    Summary Aim To evaluate the growth of Human Gingival Fibroblasts (HGFs) cultured onto sample discs of CAD/CAM zirconia and veneering ceramic for zirconia by means of Scanning Electron Microscope (SEM) analysis at different experimental times. Methods A total of 26 experimental discs, divided into 2 groups, were used: Group A) CAD/CAM zirconia (3Y-TZP) discs (n=13); Group B) veneering ceramic for zirconia discs (n=13). HGFs were obtained from human gingival biopsies, isolated and placed in culture plates. Subsequently, cells were seeded on experimental discs at 7,5×103/cm2 concentration and cultured for a total of 7 days. Discs were processed for SEM observation at 3h, 24h, 72h and 7 days. Results In Group A, after 3h, HGFs were adherent to the surface and showed a flattened profile. The disc surface covered by HGFs resulted to be wider in Group A than in Group B samples. At SEM observation, after 24h and 72h, differences in cell attachment were slightly noticeable between the groups, with an evident flattening of HGFs on both surfaces. All differences between Group A and group B became less significant after 7 days of culture in vitro. Conclusions SEM analysis of HGFs showed differences in terms of cell adhesion and proliferation, especially in the early hours of culture. Results showed a better adhesion and cell growth in Group A than in Group B, especially up to 72h in vitro. Differences decreased after 7 days, probably because of the rougher surface of CAD/CAM zirconia, promoting better cell adhesion, compared to the smoother surface of veneering ceramic. PMID:24611089

  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. 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

  16. Digital Smile Design concept delineates the final potential result of crown lengthening and porcelain veneers to correct a gummy smile.

    PubMed

    Trushkowsky, Richard; Arias, David Montalvo; David, Steven

    2016-01-01

    Prior to initiating any treatment, it is necessary to visualize the desired outcomes. It then becomes possible to formulate the steps required to achieve this result. Digital Smile Design (DSD) utilizes patient input and information gathered through diagnostic procedures to create an esthetic treatment scheme. In the case presented here, the NYUCD Esthetic Evaluation Form, intraoral and extraoral photographs, mounted diagnostic casts, physical examination, and radiographs were the diagnostic modalities. The gathered information served as a starting point for a wax-up and intraoral mock-up. This case report demonstrates how the DSD served as a template for crown lengthening procedures and design of the final porcelain veneer restorations. PMID:27433549

  17. 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

  18. 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.

  19. 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)

  20. Meeting Dental Health Needs Through Dental Education

    ERIC Educational Resources Information Center

    Morris, Alvin L.

    1972-01-01

    Dental health needs of the country cannot be met through education of more dentists. Rather, we must educate auxiliaries to perform many of the intraoral procedures now regarded the sole responsibility of dentists. (SB)

  1. 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. PMID:20922439

  2. 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

  3. Fractographic study of the behavior of different ceramic veneers on full coverage crowns in relation to supporting core materials

    PubMed Central

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

    2013-01-01

    Objectives: To observe porcelain veneer behavior of zirconia and metal-ceramic full coverage crowns when subjected to compression testing, comparing zirconia cores to metal cores. Study Design: The porcelain fracture surfaces of 120 full coverage crowns (60 with a metal core and 60 with a zirconia core) subjected to static load (compression) testing were analyzed. Image analysis was performed using macroscopic processing with 8x and 12x enlargement. Five samples from each group were prepared and underwent scanning electron microscope (SEM) analysis in order to make a fractographic study of fracture propagation in the contact area and composition analysis in the most significant areas of the specimen. Results: Statistically significant differences in fracture type (cohesive or adhesive) were found between the metal-ceramic and zirconia groups: the incidence of adhesive fracture was seen to be greater in metal-ceramic groups (92%) and cohesive fracture was more frequent in zirconium oxide groups (72%). The fracture propagation pattern was on the periphery of the contact area in the full coverage crown restorations selected for fractographic study. Conclusions: The greater frequency of cohesive fracture in restorations with zirconia cores indicates that their behavior is inadequate compared to metal-ceramic restorations and that further research is needed to improve their clinical performance. Key words:Zirconia, zirconium oxide, fractography, composition, porcelain veneers, fracture, cohesive, adhesive. PMID:24455092

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

    PubMed

    Arapostathis, Konstantinos; Arhakis, Aristidis; Kalfas, Sotiris

    2005-01-01

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

  6. 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.

  7. 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. PMID:27587574

  8. 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

  9. 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

  10. 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…

  11. 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;…

  12. 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,…

  13. 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…

  14. The future dental workforce?

    PubMed

    Gallagher, J E; Wilson, N H F

    2009-02-28

    The Editor-in-Chief of the BDJ has previously raised important questions about dental workforce planning and the implications for dental graduates of recent changes and pressures. It is now time to revisit this issue. Much has changed since the last workforce review in England and Wales, and the rate of change is in all probability set to increase. First, at the time of writing this paper the momentous step of including dental care professionals (DCPs) on General Dental Council (GDC) registers in the United Kingdom has recently been completed. Second, the Scope of Practice of all dental professionals has been under consultation by the General Dental Council, and research evidence suggests that greater use should be made of skill-mix in the dental team. Third, within England, Lord Darzi has just published the 'Final Report of the NHS Next Stage Review', which emphasises 'quality care' and 'team-working' as key features of healthcare; this report was accompanied by an important document entitled 'A High Quality Workforce', in which plans for local workforce planning within the NHS are outlined, placing responsibilities at national, local and regional levels. Fourth, policy makers across the UK are wrestling with addressing oral health needs, promoting health and facilitating access to dental care, all of which have implications for the nature and shape of the dental workforce. Fifth, with the impact of globalisation and European policies we are net gainers of dentists as well as having more in training. Sixth, although there have been reviews and policy initiatives by regulatory, professional and other bodies in support of shaping the dental workforce, there has been little serious consideration of skill-mix and funding mechanisms to encourage team-working. Together, these events demand that we enter a fresh debate on the future dental workforce which should extend beyond professional and national boundaries and inform workforce planning. This debate is of great

  15. 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

  16. 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

  17. Reliability and strength of all-ceramic dental restorations fabricated by direct ceramic machining (DCM).

    PubMed

    Filser, F; Kocher, P; Weibel, F; Lüthy, H; Schärer, P; Gauckler, L J

    2001-04-01

    All-ceramic dental bridges for the molar region are not yet available at reasonable costs. The novel direct ceramic machining (DCM) process allows an easy, reliable and rapid fabrication for all-ceramic dental restorations with high mechanical strength and good biocompatibility. In DCM, an enlarged framework is easily milled out of a pre-fabricated porous ceramic blank made of zirconia. After sintering to full density, no further time-consuming hard machining with diamond tools is needed. For individual esthetical requirements, the framework is coated with a veneer porcelain. Compared to the commercially available In-Ceram Alumina and IPS Empress2 restorations, the mechanical strength of zirconia frameworks is twice as high, allowing the restorations to bear the high mastication forces in the molar region. In terms of reliability, zirconia bridges fabricated by the DCM process are also superior to In-Ceram Alumina and IPS Empress2. A clinical study of three-unit dental bridges in the molar region found no problems after the first year of observation. PMID:11697309

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

    ERIC Educational Resources Information Center

    Lind, Patricia; Germano, Catherine

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

  19. Effect of veneer side wettability on bonding quality of Eucalyptus globulus plywoods prepared using a tannin-phenol-formaldehyde adhesive.

    PubMed

    Vázquez, G; González-Alvarez, J; López-Suevos, F; Antorrena, G

    2003-05-01

    The influence of rotary peeling on the different behaviour of tight and loose sides of Eucalyptus globulus veneers has been studied. The presence of lathe checks on the loose sides favours wettability, the contact angle decreasing more rapidly on these sides than on tight sides. Additionally, pine bark tannins improved wettability due to their surfactant character. Bonding quality tests carried out on plywoods prepared using a tannin-phenol-formaldehyde adhesive showed that fracture almost invariably occurred in a glue line with at least one loose side, where wood failure appeared. This behaviour, confirmed by analysing the glue lines by means of fluorescence microscopy, was due to the large surface alterations of the loose sides which reduced mechanical strength but allowed greater penetration of the adhesive giving rise to high wood failure. PMID:12507878

  20. Comparative study of the shear bond strength of various veneering materials on grade II commercially pure titanium

    PubMed Central

    Lee, Eun-Young; Jun, Sul-Gi; Wright, Robert F.

    2015-01-01

    PURPOSE To compare the shear bond strength of various veneering materials to grade II commercially pure titanium (CP-Ti). MATERIALS AND METHODS Thirty specimens of CP-Ti disc with 9 mm diameter and 10 mm height were divided into three experimental groups. Each group was bonded to heat-polymerized acrylic resin (Lucitone 199), porcelain (Triceram), and indirect composite (Sinfony) with 7 mm diameter and 2 mm height. For the control group (n=10), Lucitone 199 were applied on type IV gold alloy castings. All samples were thermocycled for 5000 cycles in 5-55℃ water. The maximum shear bond strength (MPa) was measured with a Universal Testing Machine. After the shear bond strength test, the failure mode was assessed with an optic microscope and a scanning electron microscope. Statistical analysis was carried out with a Kruskal-Wallis Test and Mann-Whitney Test. RESULTS The mean shear bond strength and standard deviations for experimental groups were as follows: Ti-Lucitone 199 (12.11 ± 4.44 MPa); Ti-Triceram (11.09 ± 1.66 MPa); Ti-Sinfony (4.32 ± 0.64 MPa). All of these experimental groups showed lower shear bond strength than the control group (16.14 ± 1.89 MPa). However, there was no statistically significant difference between the Ti-Lucitone 199 group and the control group, and the Ti-Lucitone 199 group and the Ti-Triceram group. Most of the failure patterns in all experimental groups were adhesive failures. CONCLUSION The shear bond strength of veneering materials such as heat-polymerized acrylic resin, porcelain, and indirect composite to CP-Ti was compatible to that of heatpolymerized acrylic resin to cast gold alloy. PMID:25722841

  1. Advances in dental materials.

    PubMed

    Vaderhobli, Ram M

    2011-07-01

    The use of materials to rehabilitate tooth structures is constantly changing. Over the past decade, newer material processing techniques and technologies have significantly improved the dependability and predictability of dental material for clinicians. The greatest obstacle, however, is in choosing the right combination for continued success. Finding predictable approaches for successful restorative procedures has been the goal of clinical and material scientists. This article provides a broad perspective on the advances made in various classes of dental restorative materials in terms of their functionality with respect to pit and fissure sealants, glass ionomers, and dental composites. PMID:21726695

  2. 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

  3. Dental mesenchymal stem cells.

    PubMed

    Sharpe, Paul T

    2016-07-01

    Mammalian teeth harbour mesenchymal stem cells (MSCs), which contribute to tooth growth and repair. These dental MSCs possess many in vitro features of bone marrow-derived MSCs, including clonogenicity, expression of certain markers, and following stimulation, differentiation into cells that have the characteristics of osteoblasts, chondrocytes and adipocytes. Teeth and their support tissues provide not only an easily accessible source of MSCs but also a tractable model system to study their function and properties in vivo In addition, the accessibility of teeth together with their clinical relevance provides a valuable opportunity to test stem cell-based treatments for dental disorders. This Review outlines some recent discoveries in dental MSC function and behaviour and discusses how these and other advances are paving the way for the development of new biologically based dental therapies. PMID:27381225

  4. Glossary of Dental Terms

    MedlinePlus

    ... geta poker friv Home InfoBites Find an AGD Dentist Your Family's Oral Health About the AGD Dental ... and shape of teeth performed by a general dentist | More Edentulous having lost most or all of ...

  5. American Dental Association

    MedlinePlus

    ... Oral Health Topics ADVERTISEMENT Advocacy Advocacy Advocacy Issues Health Care Reform ADA Positions, Policies and Statements Legal Advocacy and ... Children's Dental Health Month ADA Seal of Acceptance Fluoride in Water Advocating for the Public Prevention Summit ...

  6. Dental care - child

    MedlinePlus

    ... dental exams, and getting necessary treatments such as fluoride, extractions, fillings, or braces and other orthodontics. ... provider if your infant needs to take oral fluoride . THE FIRST TRIP TO THE DENTIST Your child's ...

  7. Complications of dental surgery.

    PubMed

    Lillich, J D

    1998-08-01

    Both retrospective data and clinical experience indicate that complications of dental surgery are occasionally encountered and, to some extent, are inevitable. Many of the reported complications related to dental surgery such as incomplete removal of diseased teeth or removal of the wrong tooth can be avoided with sound preoperative planning and intraoperative technique. Diseased teeth should be properly identified prior to and during surgery. In addition, complete removal of the diseased tooth must be performed. Use of intraoperative radiographic examination to confirm the location of the diseased tooth and to document its removal cannot be overemphasized. Iatrogenic fracture of the maxillary or mandibular alveolar walls or palatine bone can be avoided by proper placement of the dental punch. The chances of developing incisional drainage or secondary sinusitis can be reduced by use of appropriate systemic antibiotics. These factors should guide the surgical approach to dental surgery to reduce the likelihood of developing common complications. PMID:9742671

  8. Infant dental care (image)

    MedlinePlus

    Even though newborns and infants do not have teeth, care of the mouth and gums is important. ... sugar water. As the child grows, establishing proper dental hygiene will promote healthy teeth and gums which ...

  9. Dental care - child

    MedlinePlus

    ... Cantor A, Zakher B, et al. Preventing dental caries in children <5 years: systematic review updating USPSTF ... nih.gov/pubmed/15606059 . Ng MW. Early childhood caries: risk-based disease prevention and management. Dent Clin ...

  10. Dental Care in Pregnancy

    MedlinePlus

    ... for you and your baby and contain less sugar that can damage your teeth. Water or low-fat milk hydrates you and contains little or no sugar. For More Information American Dental Association: Pregnancy http : / / ...

  11. 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.

  12. Dental (Odontogenic) Pain

    PubMed Central

    Renton, Tara

    2011-01-01

    This article provides a simple overview of acute trigeminal pain for the non dentist. This article does not cover oral mucosal diseases (vesiculobullous disorders) that may cause acute pain. Dental pain is the most common in this group and it can present in several different ways. Of particular interest for is that dental pain can mimic both trigeminal neuralgia and other chronic trigeminal pain disorders. It is crucial to exclude these disorders whilst managing patients with chronic trigeminal pain. PMID:26527224

  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. 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

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Standards for Licensing Dental Hygienists and 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...

  15. 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

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Standards for Licensing Dental Hygienists and 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...

  16. 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

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Standards for Licensing Dental Hygienists and 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...

  17. 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 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...

  18. 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

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Standards for Licensing Dental Hygienists and 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...

  19. Dental fitness classification in the Canadian forces.

    PubMed

    Groves, Richard R

    2008-01-01

    The Canadian Forces Dental Services utilizes a dental classification system to identify those military members dentally fit for an overseas deployment where dental resources may be limited. Although the Canadian Forces Dental Services dental classification system is based on NATO standards, it differs slightly from the dental classification systems of other NATO country dental services. Data collected by dental teams on overseas deployments indicate a low rate of emergency dental visits by Canadian Forces members who were screened as dentally fit to deploy. PMID:18277717

  20. 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

  1. 21 CFR 872.3100 - Dental amalgamator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 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 dental... and dental alloy particles, such as silver, tin, zinc, and copper. The mixed dental amalgam...

  2. 21 CFR 872.3100 - Dental amalgamator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 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 dental... and dental alloy particles, such as silver, tin, zinc, and copper. The mixed dental amalgam...

  3. 21 CFR 872.3100 - Dental amalgamator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 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 dental... and dental alloy particles, such as silver, tin, zinc, and copper. The mixed dental amalgam...

  4. 21 CFR 872.3100 - Dental amalgamator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 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 dental... and dental alloy particles, such as silver, tin, zinc, and copper. The mixed dental amalgam...

  5. 21 CFR 872.3100 - Dental amalgamator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 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 dental... and dental alloy particles, such as silver, tin, zinc, and copper. The mixed dental amalgam...

  6. 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, D.O.; Healy, R.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. Published in 2011 by John Wiley & Sons, Ltd.

  7. 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…

  8. 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)

  9. Dental practice network of U.S. dental schools.

    PubMed

    Fisher, Monica A; Beeson, Dennis C; Hans, Mark G

    2009-12-01

    As dental schools incorporate training in evidence-based dentistry (EBD) into their curricula, students must learn how to critically evaluate systematic reviews and meta-analyses. It is important that dental education in the United States support the American Dental Association's position statement on EBD, which defines "best evidence" as data obtained from all study designs. Given that much evidence is missing when EBD is derived from Cochrane Systematic Reviews' randomized clinical trials, we propose the creation of a dental practice network of U.S. dental schools. We developed an electronic clinical dentistry research database for EBD using Epi-Info (available at www.cdc.gov/epiinfo/downloads.htm). As a free, public use software, Epi-Info provides the foundation for the development of clinical research databases that can increase the research capacity through multisite studies designed to generate outcomes data on the effectiveness of dental treatment. The creation of a dental practice network of dental schools with their large number of patients would expand the research capacity for EBD practice and advance the EBD science regarding the effectiveness of dental treatment. The next step is to link clinical dental researchers/educators at multiple dental schools through a collaborative clinical research network, so that the findings can be applied to the EBD component of problem-based learning curricula of dental education. PMID:20007494

  10. 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. PMID:22163922

  11. 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

  12. 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. PMID:25231150

  13. Dental Health and Orthodontic Problems

    MedlinePlus

    ... Text Size Email Print Share Dental Health and Orthodontic Problems Page Content Article Body Dental Health Twin ... color can be tinted to match the teeth. Orthodontic Problems Crooked teeth, overbites and underbites are best ...

  14. Infection Control in Dental Settings

    MedlinePlus

    ... Based Dental Sealant Programs Dental Sealant FAQs Sealant Efficiency Assessment for Locals and States ... of infection control remain unchanged, new technologies, materials, equipment, and data require continuous evaluation of current ...

  15. DENTAL PULP TISSUE ENGINEERING

    PubMed Central

    Demarco, FF; Conde, MCM; Cavalcanti, B; Casagrande, L; Sakai, V; Nör, JE

    2013-01-01

    Dental pulp is a highly specialized mesenchymal tissue, which have a restrict regeneration capacity due to anatomical arrangement and post-mitotic nature of odontoblastic cells. Entire pulp amputation followed by pulp-space disinfection and filling with an artificial material cause loss of a significant amount of dentin leaving as life-lasting sequelae a non-vital and weakened tooth. However, regenerative endodontics is an emerging field of modern tissue engineering that demonstrated promising results using stem cells associated with scaffolds and responsive molecules. Thereby, this article will review the most recent endeavors to regenerate pulp tissue based on tissue engineering principles and providing insightful information to readers about the different aspects enrolled in tissue engineering. Here, we speculate that the search for the ideal combination of cells, scaffolds, and morphogenic factors for dental pulp tissue engineering may be extended over future years and result in significant advances in other areas of dental and craniofacial research. The finds collected in our review showed that we are now at a stage in which engineering a complex tissue, such as the dental pulp, is no longer an unachievable and the next decade will certainly be an exciting time for dental and craniofacial research. PMID:21519641

  16. Maintaining proper dental records.

    PubMed

    Leeuw, Wilhemina

    2014-01-01

    Referred to as Standard of Care, the legal duty of a dentist requires exercising the degree of skill and care that would be exhibited by other prudent dentists faced with the same patient-care situation. Primarily, the goal of keeping good dental records is to maintain continuity of care. Diligent and complete documentation and charting procedures are essential to fulfilling the Standard of Care. Secondly, because dental records are considered legal documents they help protect the interest of the dentist and/or the patient by establishing the details of the services rendered. Patients today are better educated and more assertive than ever before and dentists must be equipped to protect themselves against malpractice claims. Every record component must be handled as if it could be summoned to a court room and scrutinized by an attorney, judge or jury. Complete, accurate, objective and honest entries in a patient record are the only way to defend against any clinical and/or legal problems that might arise. Most medical and dental malpractice claims arise from an unfavorable interaction with the dentist and not from a poor treatment outcome. By implementing the suggestions mentioned in this course, dental health care professionals can minimize the legal risks associated with the delivery of dental care to promote greater understanding for patients of their rights and privileges to their complete record. PMID:24834675

  17. 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. PMID:18478885

  18. 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…

  19. Dental Hygiene Realpolitik Affecting Education.

    ERIC Educational Resources Information Center

    Bader, James D.

    1991-01-01

    Current conditions in dental hygiene influencing professional education are discussed. Workplace/practice issues include dental hygiene care as a component of dental practice, content, effects, and quality of care, hygienist supply and demand, and job satisfaction. Professional issues include the knowledge base, definitions of practice, and…

  20. 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…

  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. [Casting of dental alloys with special reference to the bonding capacity of Ni-Cr alloys].

    PubMed

    Weber, H

    1979-07-01

    A short review on castability of dental alloys -- for which a definition is proposed -- reflects the different factors influencing the results of a casting. In this case solid sieves and plates are cast by use of one gold-base alloy (Type III) and two base metal alloys used for porcelain veneering. All three alloys filled the sieve pattern to a 100%, whereas they performed differently when cast as thin, solid squares. The most continuous results were achieved with a Ni-Cr-alloy whose melting temperature can be recognized since the ingots flow together when this point is reached. Since the plate pattern is most difficult to cast due to surface to bulk ratio it is assumed that a complete casting can only be achieved when the performance of the alloy is good and all required conditions match. Thus, this type of test seems to be suitable to determine the castability of a dental alloy. The sieve test should be used to investigate and to improve the influence of the different factors as for example burnout time and temperature of the mold and sprue size. PMID:380961

  3. Balancing the risks and benefits associated with cosmetic dentistry - a joint statement by UK specialist dental societies.

    PubMed

    Alani, A; Kelleher, M; Hemmings, K; Saunders, M; Hunter, M; Barclay, S; Ashley, M; Djemal, S; Bishop, K; Darbar, U; Briggs, P; Fearne, J

    2015-05-01

    Cosmetic dentistry has become increasingly popular, largely as a result of social trends and increased media coverage. This understandable desire for the alleged 'perfect smile' needs to be tempered with an appropriate awareness of the significant risks associated with invasive cosmetic procedures such as veneers and crowns. Patients need to be properly informed that elective removal of healthy enamel and dentine can result in pulpal injury and poorer periodontal health in the longer term, particularly if they are young. The duty of candour means that they ought to be informed that aggressive reduction of sound tooth tissue is not biologically neutral and results in structural weakening of their teeth. Less invasive procedures such as bleaching on its own or for example, combined with direct resin composite bonding, can satisfy many patient's demands, while still being kinder to teeth and having much better fall-back positions for their future requirements. It is the opinion of the British Endodontic Society, British Society for Restorative Dentistry, Restorative Dentistry UK, Dental Trauma UK, British Society of Prosthodontics and the British Society of Paediatric Dentistry that elective invasive cosmetic dental treatments can result in great benefit to patients, but that some aggressive treatments used to achieve them can produce significant morbidities in teeth which were previously healthy. This is a worrying and growing problem with many ethical, legal and biologic aspects, but many adverse outcomes for patients who request cosmetic dental improvements are preventable by using biologically safer initial approaches to treatment planning and its provision. PMID:25952437

  4. [Hardening of dental instruments].

    PubMed

    Gerasev, G P

    1981-01-01

    The possibility of prolonging the service life of stomatological instruments by the local hardening of their working parts is discussed. Such hardening should be achieved by using hard and wear-resistant materials. The examples of hardening dental elevators and hard-alloy dental drills are given. New trends in the local hardening of instruments are the treatment of their working parts with laser beams, the application of coating on their surface by the gas-detonation method. The results of research work and trials are presented. PMID:7300627

  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. Dental Support Organizations.

    PubMed

    Dufurrena, Quinn

    2015-01-01

    The Association of Dental Support Organizations is a recently formed association of 33 companies representing a range of management and support services for dental practices. These organizations do not engage in the practice of dentistry, although in some cases they operate as holding companies for practices that do, thus separating the legal responsibility of providing treatment from the management and flow of funds. This report summarizes some of the recent trends in oral health care and dentists' practice patterns that are prompting the increased prevalence of this model. The general functioning of the DSO model is described, including some common variations, and the core values of ADSO are featured. PMID:26455048

  7. 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

    ... the Federal Register on February 16, 2010 (75 FR 7037). At the request of the State Agency, the... 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...

  8. 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

  9. 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.

  10. 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. PMID:25802916

  11. 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.

  12. 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

  13. Skylab Dental Examination

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Skylab 2 Commander Charles Conrad is seen undergoing a dental examination by the Medical Officer, Joseph Kerwin in the Skylab Medical Facility. In the absence of an examination chair, Conrad simply rotated his body to an upside down position to facilitate the procedure.

  14. Dental Health in TSC

    MedlinePlus

    ... to occur in nearly 100% of the TSC population. Not all dental pits are cavities; they are just areas where enamel did not form, but can be an area where food can build up and start a cavity. Gums The gums may have small areas of growth called gingival fibromas , which are mostly harmless and ...

  15. Dental Issues & Down Syndrome

    MedlinePlus

    ... dental school, has extra training in caring for patients with disabilities. The Special Care Dentistry Association is a resource to find a dentist ... for children who grind their teeth, because the risk of the child choking on the mouthguard if it breaks ... Academy of Pediatric Dentistry www.aapd.org Find a dentist at www. ...

  16. Finding Dental Care

    MedlinePlus

    ... Main Content National Institute of Dental and Craniofacial Research (NIDCR) Improving the Nation's Oral Health National Institutes of Health Español Staff Directory A–Z Index Search Text size: Website Contents NIDCR Home Oral Health Diseases and Conditions Gum ...

  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. [Instruction in dental radiology].

    PubMed

    van der Sanden, W J M; Kreulen, C M; Berkhout, W E R

    2016-04-01

    The diagnostic use of oral radiology is an essential part of daily dental practice. Due to the potentially harmful nature of ionising radiation, the clinical use of oral radiology in the Netherlands is framed by clinical practice guidelines and regulatory requirements. Undergraduate students receive intensive theoretical and practical training in practical and theoretical radiology, with the aim of obtaining the 'Eindtermen Stralingshygiëne voor Tandartsen en Orthodontisten'-certificate, which is required for legal permission to use oral radiology in dental practice. It is recommended that the curriculum be expanded to include the areas of knowledge required to qualify for the 'Eindtermen Stralingshygiëne voor het gebruik van CBCT-toestellen door tandartsen' (the certificate for the use of conebeam radiology by dentists). The general dental practitioner is faced with changing laws and regulations in all areas of practice. One of the most significant legal changes in the field of dental radiology was the introduction of the new radiation protection and safety rules in 2014. Moreover, a large group of dentists is also being confronted with the transition from conventional to digital images, with all its challenges and changes in everyday practice. PMID:27073811

  19. 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

  20. Ethics of dental health screening.

    PubMed

    Janakiram, Chandrashekar; Taha, Farheen

    2016-01-01

    Screening is the detection of disease at a point in its natural history when it is not yet symptomatic. In the natural history of dental caries, for example, the incipient lesions are at a reversible stage, which is a pre-symptomatic or an unrecognised symptomatic disease. Ideally, this is the stage during which screening should identify the risk of dental caries; however, presently, the so-called dental screening employed identifies the clinical cavitation of the tooth, which is very obvious to the individual. The individual already knows that he/she has dental caries and needs treatment, which the screening personnel (dental doctor) explains again during the screening procedure. Is it ethical to call such an event screening? The mushrooming of dental teaching hospitals has promoted regular screening of dental diseases among the communities and schoolchildren through their community dentistry-related activities. More often, it is a dental "check-up" that is carried out on the pretext of screening for dental diseases. Though the basic intention of this activity is to promote awareness of dental diseases and promote good health, there is also a hidden agenda to it. An artificial demand for dental care is created that is easily capitalised on by the dental teaching institutions to enhance its clinical activity. Dental screening is doing more harm than good as patients are made aware of the diseases for which they may not be able to afford treatment. This narrative review gives an account of the scientific evidence on screening for oral diseases, the current practices in screening and the ethical dilemmas of dental screening programmes. PMID:27474698

  1. 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 ( ...

  2. 21 CFR 872.3240 - Dental bur.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 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 rotary... materials intended for use in the fabrication of dental devices. (b) Classification. Class I...

  3. 21 CFR 872.3240 - Dental bur.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 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 rotary... materials intended for use in the fabrication of dental devices. (b) Classification. Class I...

  4. 21 CFR 872.3240 - Dental bur.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 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 rotary... materials intended for use in the fabrication of dental devices. (b) Classification. Class I...

  5. 21 CFR 872.3240 - Dental bur.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 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 rotary... materials intended for use in the fabrication of dental devices. (b) Classification. Class I...

  6. 21 CFR 872.3240 - Dental bur.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 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 rotary... materials intended for use in the fabrication of dental devices. (b) Classification. Class I...

  7. 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…

  8. 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…

  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. PMID:22855595

  10. Importance of Dental Records in Forensic Dental Identification

    PubMed Central

    Waleed, Petro; Baba, Feras; Alsulami, Salem; Tarakji, Bassel

    2015-01-01

    Introduction: The patient’s record maintains all the diagnostic information with regards to patients and contains valuable information that can be beneficial to the dentist as well as legal authorities during forensic human identification. Aim: Objective of the study was to compare dental records with an ideal dental record form, as well as to compare between dental records of private clinics and academic hospitals and to assess the awareness and the knowledge of the dentists regarding the maintenance of their dental records accurate for medico-legal purposes. Material and Methods: A comparative cross-sectional study between records kept in private clinics and academic teaching hospitals in Khartoum locality. Results: Our results showed that Students are more likely to encounter accurate dental records more than dentists in private clinics. In conclusion Students are more aware regarding medicolegal purposes of maintenance of dental records. Accurate maintenance of dental records is more among dental students. Therefore, private clinics encounter dental records as financial documents. PMID:25870492

  11. Dental Enamel Defects and Celiac Disease

    MedlinePlus

    ... Nutrition Home : Dental Enamel Defects and Celiac Disease Dental Enamel Defects and Celiac Disease Celiac disease manifestations ... affecting any organ or body system. One manifestation—dental enamel defects—can help dentists and other health ...

  12. Dental problems in athletes.

    PubMed

    Inouye, Jill; McGrew, Chris

    2015-01-01

    Orofacial injuries and diseases occur in athletes, and they may not always have access to dentists. Therefore team physicians should be aware of the common injuries and initial management. Treatment of dental injuries will depend on whether the teeth are primary or permanent. The most common type of fracture is crown fracture, but there are other dental injuries that can lead to future complications if not treated promptly and monitored closely. Tooth avulsions need to be handled properly, and athletes should see a dentist as soon as possible. Despite the urgency of some injuries, other orofacial injuries or diseases, such as lacerations and caries, should not be overlooked. Proper education and use of mouth guards can assist athletes in reducing their risk of orofacial injuries. PMID:25574879

  13. 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…

  14. [Biocompatibility of dental amalgam].

    PubMed

    Missias, P

    1990-10-01

    The purpose of the present review was to present a detailed description of those current scientific results and opinions relative to the biocompatibility of dental amalgam. The first section of the percent review to the pulpar reactions caused by amalgam fillings, especially when no protective base has been used, while the second part concerns itself with the biocompatibility of the dental amalgam per se. Specifically, reference is made to: a) the adverse reactions due to amalgam fillings both on the patient's physiological system and on the dentist's employing the material under consideration. b) those investigation results bearing a relation on the amount of mercury liberated during the amalgam filling procedures, i.e., mixing, condensation, finishing and polishing and/or removal of old amalgam fillings. c) Liberation of mercury, as well as metallic ions in the patients mouth cavity during chewing and/or during the process of intrabuccal galvanization and corrosion, and d) on the amount of mercury traced in the blood and urine of the patient following amalgam fillings. No conclusive evidence on any adverse reactions on the patient's health, attributable to the liberation of mercury from amalgam fillings, could be presented by the scientific investigations under consideration. Moreover, the number of cases reported on toxic reactions due to dental amalgam is negligible compared to the immense number of amalgam fillings performed in practice. It merits mentioning in this connection, however, the fact that the total amount of mercury attained by the patient from any other source, in conjunction with that liberated from amalgam fillings, could by all means contribute to a number of toxic reactions on the patient's health in general. Conclusively, one could state without reservations, that dental amalgam fillings per se are by and large free of toxic reactions on the patient, based on current scientific observations. Mentioning is finally made on several simple but

  15. Fluorescence of dental porcelain.

    PubMed

    Monsénégo, G; Burdairon, G; Clerjaud, B

    1993-01-01

    This study of the fluorescence of natural enamel and of dental ceramics shows the fluorescence of ceramics not containing rare earths decreases when the color saturation increases; the fluorescence of samples of the same shade guide are not homogenous; some guides show a strong green fluorescence; and two shade guides of the same origin can present completely different fluorescence. The cementing medium can affect the fluorescence of a ceramic prosthesis. PMID:8455155

  16. Dental Treatment Abuse

    PubMed Central

    Ataide, Ida De Noronha De; Krishnan, Ramesh; Pavaskar, Rajdeep

    2014-01-01

    These case reports highlight dental treatment abuse performed by a quack on children. The anterior teeth of these children were metal capped using cement, which were otherwise healthy. The treatment was done on children without parental consent by a quack from Denmark who gave the reason as for resolving proclination of upper permanent incisors. The unanatomic, unaesthetic metal caps were removed after the child reported to the Department of Pedodontics and Preventive Dentistry. PMID:25177645

  17. Dental digital radiography.

    PubMed

    Moore, William S

    2002-05-01

    Digital images offer tremendous advantages to dentistry in terms of the potential for lower exposure to patients, absence of darkroom or processing problems, convenience of image enhancement techniques and capacity for remote teledentistry. Digital systems are now able to acquire all types of images including panoramic and cephalometric. As technology continues to improve they may ultimately replace film as the medium of choice for dental imaging. PMID:12046403

  18. Dental treatment abuse.

    PubMed

    Chalakkal, Paul; Ataide, Ida De Noronha De; Krishnan, Ramesh; Pavaskar, Rajdeep

    2014-07-01

    These case reports highlight dental treatment abuse performed by a quack on children. The anterior teeth of these children were metal capped using cement, which were otherwise healthy. The treatment was done on children without parental consent by a quack from Denmark who gave the reason as for resolving proclination of upper permanent incisors. The unanatomic, unaesthetic metal caps were removed after the child reported to the Department of Pedodontics and Preventive Dentistry. PMID:25177645

  19. Are dental radiographs safe?

    PubMed

    Abbott, P

    2000-09-01

    Dental patients are often aware that radiation has the potential to harm them but they do not usually understand how or why and what potential harmful effects may arise from dental radiographs. The potential for undesirable effects must be balanced against the benefits obtained from radiographs. Dentists should address the concerns of patients who question the need for radiographs and allow them to make an informed decision. Data are available that relate radiation exposure levels from medical and dental radiographs to normal background exposure levels and allow comparisons with everyday risks in life. Recognized radiation authorities publish guidelines to help dentists with their use of radiographs, although, due to the time lag associated with testing and the publication of results, some of the published data may not always be entirely relevant to currently used X-ray machines and techniques. Dentists also have professional obligations not only to limit the use of radiographs to potentially beneficial situations but also to take good quality diagnostic radiographs, to limit the doses used, to use good radiation safety measures and to use modern equipment to achieve the best possible films. Radiographs must then be properly developed and viewed under appropriate conditions to gain the maximum possible diagnostic information from each exposure. PMID:11062940

  20. Dental injuries during general anaesthesia.

    PubMed

    Chadwick, R G; Lindsay, S M

    1996-04-01

    Although most anaesthetic textbooks cite dental injury as a complication of endotracheal intubation few studies have examined the extent and nature of the problem. Such damage however, formed the basis for one-third of all confirmed or potential anaesthetic claims notified to the Medical Protection Society between 1977 and 1986. This article seeks to explore the extent of the problem, outline predisposing factors, summarise current prophylactic measures and make recommendations to reduce the overall incidence. Increased awareness of the problem, by both anaesthetists and dental surgeons, coupled with appropriate prophylactic measures may result in a reduced incidence of dental injury arising from general anaesthesia. Given the high incidence of dental damage we recommend that all patients undergoing a surgical operation under endotracheal intubation should have a pre-operative dental check wherever possible. Clearly, the first dental examination would be conducted by an anaesthetist familiar with the predisposing factors. Where he/she considers there to be a higher than average risk of dental damage occurring during intubation a more specialised examination should be conducted by a dental surgeon. It may, where appropriate, be possible for remedial dental treatment to be carried out and customised mouth guards to be constructed prior to the operation. Obviously such recommendations have certain financial implications and would have to be subject to controlled cost-benefit analysis before their widespread application. PMID:8935289

  1. Resuscitation in the dental practice.

    PubMed

    Jevon, P

    2016-03-11

    The Resuscitation Council (UK) published new resuscitation guidelines in October 2015. The aim of this article is to understand these new guidelines and how dental practices should implement them. A 'resuscitation in the dental practice poster' has been designed which incorporates the new Resuscitation Council (UK) adult basic life support algorithm. This poster, endorsed by the British Dental Association, is included with this issue of the British Dental Journal. Further copies can be downloaded from: https://www.walsallhealthcare.nhs.uk/Data/Sites/1/media/documents/health-and-safety/resus.pdf. PMID:26964602

  2. Harvesting dental stem cells - Overview.

    PubMed

    Sunil, P M; Manikandan, Ramanathan; Muthumurugan; Yoithapprabhunath, Thukanayakanpalayam Ragunathan; Sivakumar, Muniapillai

    2015-08-01

    Dental stem cells have recently become one of the widely researched areas in dentistry. Ever since the identification of stem cells from various dental tissues like deciduous teeth, dental papilla, periodontal ligament and third molars, storing them for future use for various clinical applications was being explored. Dental stem cells were harvested and isolated using various techniques by different investigators and laboratories. This article explains the technical aspects of preparing the patient, atraumatic and aseptic removal of the tooth and its safe transportation and preservation for future expansion. PMID:26538883

  3. Computerized Dental Injection Fear Treatment

    PubMed Central

    Heaton, L.J.; Leroux, B.G.; Ruff, P.A.; Coldwell, S.E.

    2013-01-01

    One in four adults reports a clinically significant fear of dental injections, leading many to avoid dental care. While systematic desensitization is the most common therapeutic method for treating specific phobias such as fear of dental injections, lack of access to trained therapists, as well as dentists’ lack of training and time in providing such a therapy, means that most fearful individuals are not able to receive the therapy needed to be able to receive necessary dental treatment. Computer Assisted Relaxation Learning (CARL) is a self-paced computerized treatment based on systematic desensitization for dental injection fear. This multicenter, block-randomized, dentist-blind, parallel-group study conducted in 8 sites in the United States compared CARL with an informational pamphlet in reducing fear of dental injections. Participants completing CARL reported significantly greater reduction in self-reported general and injection-specific dental anxiety measures compared with control individuals (p < .001). Twice as many CARL participants (35.3%) as controls (17.6%) opted to receive a dental injection after the intervention, although this was not statistically significant. CARL, therefore, led to significant changes in self-reported fear in study participants, but no significant differences in the proportion of participants having a dental injection (ClinicalTrials.gov, NCT00609648). PMID:23690352

  4. Harvesting dental stem cells - Overview

    PubMed Central

    Sunil, P. M.; Manikandan, Ramanathan; Muthumurugan; Yoithapprabhunath, Thukanayakanpalayam Ragunathan; Sivakumar, Muniapillai

    2015-01-01

    Dental stem cells have recently become one of the widely researched areas in dentistry. Ever since the identification of stem cells from various dental tissues like deciduous teeth, dental papilla, periodontal ligament and third molars, storing them for future use for various clinical applications was being explored. Dental stem cells were harvested and isolated using various techniques by different investigators and laboratories. This article explains the technical aspects of preparing the patient, atraumatic and aseptic removal of the tooth and its safe transportation and preservation for future expansion. PMID:26538883

  5. Chipping Resistance of Graded Zirconia Ceramics for Dental Crowns

    PubMed Central

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

    2012-01-01

    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. PMID:22232142

  6. Interfacial adhesion of dental ceramic-resin systems

    NASA Astrophysics Data System (ADS)

    Della Bona, Alvaro

    The clinical success of resin bonding procedures for indirect ceramic restorations and ceramic repairs depends on the quality and durability of the bond between the ceramic and the resin. The quality of this bond will depend upon the bonding mechanisms that are controlled in part by the surface treatment that promotes micromechanical and/or chemical bonding to the substrate. The objective of this study is to correlate interfacial toughness (K A) with fracture surface morphological parameters of the dental ceramic-resin systems as a function of ceramic surface treatment. The analytical procedures focused on characterizing the microstructure and fracture properties of EmpressRTM ceramics (a leucite-based core ceramic, two lithia disilicate-based core ceramics, and a glass veneer) and determining the ceramic-resin adhesion zone bond strength characteristics. Microstructure and composition are controlling factors in the development of micromechanical retention produced by etching. Silane treated ceramics negated the effect of surface roughening produced by etching, inducing lower surface energy of the ceramic and, reduced bonding effectiveness. There was a positive correlation between WA, tensile bond strength (a), and KA, i.e., higher mean WA value, and higher mean sigma and KA values. This study suggests that (1) the sigma and KA values for ceramic bonded to resin are affected by the ceramic microstructure and the ceramic surface treatments; (2) the definition of the adhesion zone is essential to classify the modes of failure, which should be an integral component of all failure analyses; (3) the microtensile test may be preferable to conventional shear or flexural tests as an indicator of composite-ceramic bond quality; and (4) careful microscopic analysis of fracture surfaces and an x-ray dot map can produce a more consistent and complete description of the fracture process and interpretation of the modes of failure. The mode of failure and fractographic analyses

  7. 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…

  8. 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;…

  9. 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,…

  10. Emerging Dental Specialties and Ethics.

    PubMed

    Brown, Ronald S; Mashni, Michael

    2015-01-01

    This paper discusses ethical dimensions related to the formal recognition of emerging dental specialties. It explores several issues related to the potential emergence of several new dental specialty areas. There are good reasons that dentistry should open the door to these new specialties, and patients would benefit. The ethical considerations for and against formal acceptance are examined. PMID:26697653

  11. 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…

  12. 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.

  13. 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 telephone…

  14. Dental Health: The Basic Facts

    MedlinePlus

    ... after breakfast and before bedtime n Using a tooth-paste with fluoride in it n Flossing daily n Using a tongue scraper or brushing the tongue daily Dental Health | 1 n ... reporting any bleeding gums, tooth or jaw pain or tooth sensitivity Routine dental ...

  15. 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…

  16. Teaching Photography in Dental Schools.

    ERIC Educational Resources Information Center

    Chuman, Ted A.; Hummel, Susan K.

    1992-01-01

    Two surveys investigated the extent of photography instruction in dental schools. The first survey of 53 schools revealed that 36% had formal dental photography programs. Of 21 photography instructors surveyed in the second study, 67% had no formal training, many knew little about texts or resources, and techniques and knowledge varied. (MSE)

  17. 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

  18. Ergonomic design for dental offices.

    PubMed

    Ahearn, David J; Sanders, Martha J; Turcotte, Claudia

    2010-01-01

    The increasing complexity of the dental office environment influences productivity and workflow for dental clinicians. Advances in technology, and with it the range of products needed to provide services, have led to sprawl in operatory setups and the potential for awkward postures for dental clinicians during the delivery of oral health services. Although ergonomics often addresses the prevention of musculoskeletal disorders for specific populations of workers, concepts of workflow and productivity are integral to improved practice in work environments. This article provides suggestions for improving workflow and productivity for dental clinicians. The article applies ergonomic principles to dental practice issues such as equipment and supply management, office design, and workflow management. Implications for improved ergonomic processes and future research are explored. PMID:20448328

  19. Glucosyltransferase inactivation reduces dental caries.

    PubMed

    Devulapalle, K S; Mooser, G

    2001-02-01

    Dental caries has been an intractable disease in spite of intense dental research. The metabolic acids produced by mutans streptococci demineralize the tooth surface and lead to dental caries. The enzyme glucosyltransferase (GTF) produced by mutans streptococci is the key factor in this process. Oral bacterial GTFs use sucrose as a substrate in synthesis of either water-soluble or insoluble glucans. In this investigation, kinetic studies with divalent metal ions revealed their strong binding affinity to GTF. The metal ions also proved to be strong inhibitors of the enzyme. Here we describe a simple method of inactivating the enzyme that actively participates in dental caries by taking advantage of a Fenton reaction which requires metal ions such as iron or copper and peroxide. The hydroxyl radical ions produced via the Fenton reaction inactivate GTF, a factor in the production of dental caries. PMID:11332534

  20. 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

  1. 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. PMID:24006720

  2. Is dental caries neglect?

    PubMed

    Stevens, C L

    2014-11-01

    The recent and widespread media interest highlighting the concerning number of children with poor oral health has, at last, put paediatric dentistry well and truly under the spotlight. Whether on the front page of the Sunday Times (http://www.thesundaytimes.co.uk/sto/news/uk_news/Health/Sugar/article1433860.ece), on GDPUK forums or live Twitter feeds as ITV's The Dentists was broadcast, the whole nation has suddenly awoken to the realisation that tens of thousands of children are undergoing multiple dental extractions under general anaesthesia in the UK every year. This is of course, not a new phenomenon, so why the sudden interest? PMID:25377816

  3. 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. PMID:25257392

  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. 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. PMID:23658413

  6. 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,…

  7. 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...

  8. 21 CFR 872.6390 - Dental floss.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Dental floss. 872.6390 Section 872.6390 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6390 Dental floss. (a) Identification. Dental floss is...

  9. 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...

  10. 21 CFR 872.6390 - Dental floss.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Dental floss. 872.6390 Section 872.6390 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6390 Dental floss. (a) Identification. Dental floss is...

  11. 21 CFR 872.6390 - Dental floss.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Dental floss. 872.6390 Section 872.6390 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6390 Dental floss. (a) Identification. Dental floss is...

  12. 21 CFR 872.6390 - Dental floss.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Dental floss. 872.6390 Section 872.6390 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6390 Dental floss. (a) Identification. Dental floss is...

  13. 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...

  14. 21 CFR 872.6390 - Dental floss.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Dental floss. 872.6390 Section 872.6390 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6390 Dental floss. (a) Identification. Dental floss is...

  15. 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…

  16. 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)

  17. 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…

  18. [Maintenance care for dental implant].

    PubMed

    Kamoi, K

    1989-10-01

    Dental implant has tried at the early stage in 19th century recovering an oral function and esthetics. Technological revolutions in biochemical and new materials have developed on the remarkable change in the dental implants, nowadays we call the three generation therapy for dental implantology. There are many kinds of methods and techniques in dental implants, however a lot of troublesome complication on the process of surgical phase, construction of prothodontics and prognosis of maintenance care. In the proceedings of this symposium, I would like to propose you how to manage the maintenance care for various kind of dental implants through the methodology and case presentations. Tendenay and future for dental implants The current outlook of dental implant has increasing supply and demand not only dentists but also patients. According to Japanese Welfare Ministry's report in 1987, average missing teeth over sixty years old generations are approximately 42% in accordance with NIDR (U.S.A.) research. They are missed on ten over teeth in full 28th teeth dentitions owing to dental caries and periodontal diseases. Generally speaking, latent implant patients are occupied on the same possibility of needs for dental implants both Japan and U.S.A. Management of maintenance care The patients hardly recognized the importance of plaque control for the maintenance care in the intraoral condition after implantation. Dentists and dental staffs must be instruct patients for importance of plaque removal and control, because they already had forgotten the habit of teeth cleaning, especially in the edenturous conditions. 1) Concept of establishment in oral hygiene. Motivation and instruction for patients include very important factors in dental implants as well as in periodontal diseases. Patients who could not achieve on good oral hygiene levels obtained no good results in the long term observations. To establish good oral hygiene are how to control supra plaque surrounding tissues

  19. Career patterns of dental hygienists qualifying from the Liverpool Dental Hospital School of Dental Hygiene.

    PubMed

    Hillam, D G

    1989-04-22

    This study assesses the pattern of employment of dental hygienists who qualified from the Liverpool Dental Hospital School of Dental Hygiene between 1977 and 1986. Of the 100 students who qualified during this period, 98 responded to a questionnaire. Seventy-seven per cent were employed as dental hygienists or dental health educators at the time of the survey, which took place between October 1987 and February 1988. The results show that after an initial slight under-employment, the majority quickly found as much work as they wanted and worked for an average of 2.24 practices each. The majority chose part-time employment and there was a steady decline in the number of sessions worked from the third year after qualifying. This decline was due to domestic commitments rather than dissatisfaction with the job. Only 4% stated they would definitely not return to work as a hygienist whilst a further 10% were uncertain. PMID:2719891

  20. Child abuse and neglect: dental and dental hygiene students' educational experiences and knowledge.

    PubMed

    Thomas, John E; Straffon, Lloyd; Inglehart, Marita Rohr

    2006-05-01

    The objective of this study was to explore dental and dental hygiene students' educational experiences and knowledge concerning child abuse/neglect. Questionnaire data were collected from 233 dental (116 male/117 female; response rate=54.82 percent) and seventy-six dental hygiene students (all female; response rate=76.77 percent). Of those surveyed, 94.7 percent of the dental hygiene and 70.5 percent of the dental students reported having learned about child abuse/neglect in classroom settings, and 15.8 percent of the dental hygiene and 29.3 percent of the dental students reported having learned about it in clinical settings. Dental students reported more minutes of instruction about this topic than dental hygiene students (184.48 vs. 112.90 minutes; p=.006). Only 5.5 percent of the dental and 16.7 percent of the dental hygiene students defined child abuse correctly; 32.2 percent of the dental and 13.2 percent of the dental hygiene students did not know their legal responsibility concerning reporting child abuse; and 82.4 percent of the dental and 78.9 percent of the dental hygiene students did not know where to report child abuse. Dental care providers are likely to encounter child abuse and neglect in their professional lives and are legally required to respond to these matters. Dental and dental hygiene curricula should be revisited to ensure that students are adequately prepared for this professional task. PMID:16687641

  1. Classification schemes for dental school libraries.

    PubMed

    McMaugh, D R

    1979-12-01

    The provision of an efficient and acceptable library system for the dental literature is examined. It is suggested that an index to the dental literature is best provided by a combination of Index Medicus and Medical Subject Headings. The Library of Congress scheme would be best for an autonomous dental school and, where a dental school library is provided by a large medical library, the National Library of Medicine Classification would be suitable for dental student use. PMID:395935

  2. Strength, reliability and mode of fracture of bilayered porcelain/zirconia (Y-TZP) dental ceramics.

    PubMed

    Guazzato, Massimiliano; Proos, Kaarel; Quach, Linda; Swain, Michael Vincent

    2004-09-01

    The aim of this study was to investigate the biaxial flexural strength, reliability and the mode of fracture of bilayered porcelain/zirconia (Y-TZP) disks. For this purpose, 80 specimens were made from conventional dental porcelain and Y-TZP core ceramic, and equally divided into four groups as follows: monolithic specimens of porcelain; monolithic specimens of core material; bilayered specimens with the porcelain on top (facing the loading piston during testing); bilayered specimens with core material on top. The maximum load at fracture was calculated with a biaxial flexural test and finite element analysis was used to estimate the maximum tensile stress at fracture. Results were analyzed with one-way ANOVA, Tukey HSD. The reliability of strength was analyzed with the Weibull distribution. SEM was used to identify the initial crack and characterize the fracture mode. Monolithic core specimens and bilayered sample with the core material on the bottom were statistically significantly stronger than monolithic porcelain disks and bilayered samples with the porcelain on the bottom. The study, which was conducted with sample configurations that reproduce the clinical situation of crowns and fixed partial dentures, indicates that the material which lies on the bottom surface dictates the strength, reliability and fracture mode of the specimens. The contribution of strong and tough core materials to the performance of all-ceramics restorations may be offset by the weaker veneering porcelain if the actual distribution of the tensile stresses within the restoration is not taken into consideration. PMID:15109867

  3. The effect of repeated porcelain firings on corrosion resistance of different dental alloys

    PubMed Central

    Karahan, Ismail; Polat, Serdar; Malkoc, Meral Arslan; Dalkiz, Mehmet

    2013-01-01

    PURPOSE The aim of this study was to evaluate the effects of repeated porcelain firing process on the corrosion rates of the dental alloys. MATERIALS AND METHODS Cr-Co, Cr-Ni and Pd-Ag alloys were used for this study. Each metal supported porcelain consisted of 30 specimens of 10 for 7, 9 and 11 firing each. Disc-shaped specimens 10 mm diameter and 3 mm thickness were formed by melting alloys with a propane-oxygen flame and casted with a centrifuge casting machine and then with the porcelain veneer fired onto the metal alloys. Corrosion tests were performed in quintuplicate for each alloy (after repeated porcelain firing) in Fusayama artificial saliva solution (pH = 5) in a low thermal-expansion borosilicate glass cell. Tamhane and Sheffe test was used to compare corrosion differences in the results after repeated firings and among 7, 9 and 11 firing for each alloy. The probability level for statistical significance was set at α=0.05. RESULTS The corrosion resistance was higher (30 mV), in case of 7 times firing (Commercial). On the other hand, it was lower in case of 11 times firing (5 mV) (P<.05). CONCLUSION Repeated firings decreased corrosion resistance of Pd-Ag, Cr-Co and Cr-Ni alloys. The Pd-Ag alloy exhibited little corrosion in in vitro tests. The Cr-Ni alloy exhibited higher corrosion resistance than Cr-Co alloys in in vitro tests. PMID:23507983

  4. Positive ethics and dental students.

    PubMed

    Abelson, Sigmund H

    2008-01-01

    Recent negative publicity has drawn attention away from recognizing and celebrating the ways today's dental students differ in a positive fashion from previous generations of dental students who may have suffered the same ethical lapses we are hearing about now. Dental students are more diverse than their predecessors and learn to develop a sense of integrity that encompasses more toleration of alternative cultures. They are group-oriented, which expresses itself in sharing responsibility for their colleagues, both in educational settings and in their practices. With guidance from senior dentists and organized dentistry, they will contribute inclusiveness and group responsibility and thus strengthen the profession. PMID:18777890

  5. 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.

  6. Head and neck cancer, dental implants, and dental oncology.

    PubMed

    Garg, Arun; Guez, Ghislaine

    2011-01-01

    Head and neck cancer is a real presence in the dental-implant world--patients who undergo surgery, chemotherapy, and/or radiation often seek the assistance of dental-implant practitioners to restore them to better function; other patients who have had implants in place for years will return with questions regarding how their treatment will be affected by the presence of their dental implant. As oral-cancer treatment modalities are rapidly changing, practitioners struggle to keep up with the literature surrounding this important subset of the dental-implant population. This month, we look at the numbers of patients suffering from oral cancers, consider the different treatment options for patients with oral cancers, and investigate the role that implants play in improving therapeutic outcomes or changing treatment course. PMID:21323003

  7. Increasing dental student diversity through the UNLV Dental Prospects Program.

    PubMed

    McClain, Mildred A; Jones, Francis R; McClain, Clifford R; Curd, Francis M

    2013-05-01

    Adequately providing for the health care of the growing minority population in the United States requires increased racial and ethnic diversity of the health care workforce. Long-term diversity in the dental profession depends on a more diverse student population in dental schools. The University of Nevada, Las Vegas School of Dental Medicine's (UNLV SDM) Dental Prospects Club is a predental education program that has increased the number of underrepresented minority and disadvantaged students in the school by concentrating on outreach, recruitment, and retention initiatives. The approaches used by the club members and faculty advisors to increase the number of underrepresented minority students recruited to and enrolled in the UNLV SDM are discussed in this report. Also described are the strategies, methods, internal infrastructure, and organizational support used to increase the number of underrepresented minority students at the school. PMID:23658399

  8. 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. PMID:24769152

  9. On the interfacial fracture of porcelain/zirconia and graded zirconia dental structures

    PubMed Central

    Chai, Herzl; Lee, James J.-W; Mieleszko, Adam J.; Chu, Stephen J.; Zhang, Yu

    2014-01-01

    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-bend 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 FEA taking into account stress shielding effects due to the presence of adjacent channel cracks. The resulting GC was well less than commonly reported values for similar systems. Fracture in the graded Y-TZP samples occurred by 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. PMID:24769152

  10. 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.

  11. Before and After (Dental Restorations)

    MedlinePlus

    FAQs | Common Questions Why see a prosthodontist? Dentures Dental Implants Board Certification Improving Your Smile Conditions & Symptoms | ... of Care in the Restoration and Replacement of Teeth This site brought to you by: American College ...

  12. Electronic Dental Records System Adoption.

    PubMed

    Abramovicz-Finkelsztain, Renata; Barsottini, Claudia G N; Marin, Heimar Fatima

    2015-01-01

    The use of Electronic Dental Records (EDRs) and management software has become more frequent, following the increase in prevelance of new technologies and computers in dental offices. The purpose of this study is to identify and evaluate the use of EDRs by the dental community in the São Paulo city area. A quantitative case study was performed using a survey on the phone. A total of 54 offices were contacted and only one declinedparticipation in this study. Only one office did not have a computer. EDRs were used in 28 offices and only four were paperless. The lack of studies in this area suggests the need for more usability and implementation studies on EDRs so that we can improve EDR adoption by the dental community. PMID:26262001

  13. 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

  14. Rethinking tenure in dental education.

    PubMed

    Slayton, Rebecca L; Kachalia, Parag R; Lozano-Pineda, Juanita; Rolf, David D; Kovarik, Robert E; Dillon, Joycelyn A

    2012-05-01

    In the midst of changes in the environment of academic dentistry over the past two decades, reform of traditional tenure is one way for dental schools to respond to these changes while maintaining scholarly, evidence-based learning environments. Challenges facing academic dentistry today and in the future include a crisis in workforce capacity, difficulty attracting recent graduates into academic positions, overburdened faculty members with limited time for scholarly activity, loss of tenured faculty members due to retirement, and a potentially diminished voice for dental schools within the parent university. The purpose of this opinion article is to suggest ways to reform the current tenure system in dental education as a means of improving recruitment and retention of new faculty members while maintaining or increasing scholarly activity within dental schools. PMID:22550103

  15. Panoramic Dental X-Ray

    MedlinePlus

    ... X-ray? What is Panoramic X-ray? Panoramic radiography , also called panoramic x-ray , is a two- ... Exams Dental Cone Beam CT X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety About this Site ...

  16. Developmental Problems and Dental Morphology

    ERIC Educational Resources Information Center

    Goodwin, William C., Jr.; Erickson, Marilyn T.

    1973-01-01

    Ninety-five subjects (mean age 55 months) with mental retardation, learning disabilities, and/or minimal brain dysfunction and 47 control subjects (mean age 46 months) were compared to determine the relationship between developmental problems and dental morphology. (Author)

  17. [Persistent fever of dental origin].

    PubMed

    Pernice, L; Ribault, J Y; Fourestier, J; Gacon, J; Quilichini, R; Aubert, L; Chaffanjon, P; Roubaudi, G

    1990-01-01

    Based on 5 cases of unexplained prolonged fever, the authors stress the need to systematically look for a dental focus of infection. They discuss the difficulties in determining the site of the probable causal focus and stress the uncertain pathogenic relationship between the dental focus of infection and the fever. The extraction of infected teeth leads to a cure, however, the functional disadvantages of multiple extractions need to be carefully taken into account. PMID:2130447

  18. 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.

  19. 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

  20. 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)

  1. Dental Therapy Assistant: Quality of Restorations Placed and Finished.

    ERIC Educational Resources Information Center

    Heid, Theodore H.; Bair, Jeffrey H.

    The U.S. Army Dental Corps has implemented a new concept of dental care delivery, formally identified as the Improved Dental Care Delivery System. The concept is based on the conservation of professional manpower resources through the use of dental treatment teams employing expanded duty dental assistants. Dental Therapy Assistant (DTA) is the…

  2. Mouthrinses and dental caries.

    PubMed

    2002-10-01

    Mouthrinsing for the prevention of dental caries in children and adolescents was established as a mass prophylactic method in the 1960s and has shown average efficacy of caries reduction between 20-50%. Commonly, weekly or twice monthly rinsing procedures using neutral 0.2% NaF solutions have been used in schools or institutions in areas with low fluoride concentrations in the drinking water. Today, when dental caries has declined substantially in the western countries, and relatively few individuals are suffering from caries, the efficiency of large scale mouthrinsing is questioned and more individual approaches of caries prevention strategies are needed. For this reason individual caries risk assessments are necessary, utilising diagnostic tools with the aim of explaining the main causes of the caries disease. Therefore in high risk patients, daily mouthrinses using 0.05% NaF can be recommended combined with other selective preventive measures such as sugar restriction, improved oral hygiene, antibacterial treatments, and so forth. Mouthrinsing solutions have therefore been combined with antiplaque agents like chlorhexidine and other agents which can improve the caries preventive effect not only in high caries risk patients, including those with dry mouth problems and root caries. Other agents than sodium fluoride have been used, such as stannous and amine fluoride with proven clinical effects. However, although a series of new formulas of mouthrinses containing fluoride combined with different antiplaque agents have shown promising antibacterial and antiplaque efficacy, their long-term clinical effects are sparsely documented. Acute and chronic side effects from established and recommended mouthrinsing routines are extremely rare but ethanol containing products should not be recommended to children for long-term use or to individuals with alcohol problems. Patients with dry mouth problems should avoid mouthrinses containing high concentration of detergent

  3. Visibility of dental pulp spaces in dental ultrasound.

    PubMed

    Szopinski, K T; Regulski, P

    2014-01-01

    The purpose of this study was to assess the feasibility of dental ultrasound with conventional sonographic equipment. The teeth of three adult volunteers who had cone beam CT examinations performed previously with clinical indications and one extracted tooth were examined using linear and compact (hockey stick) sonographic probes. The sonographic images were compared with cone beam CT images reconstructed accordingly. Dental pulp spaces were demonstrated in all teeth not covered with prosthetic crowns. The dentin and pulp were best visualized at the level of the neck of the teeth. The dentin was hypoechoic, and the superficial layer comprising the cementum and the pulp spaces were hyperechoic. Dental ultrasound is feasible with general purpose sonographic machines. The buccal surfaces of all teeth are accessible with a compact (hockey stick) probe. Visualization and differentiation of dental pulp spaces, dentin and the superficial layer comprising cementum is possible in the portions of teeth not covered by the alveolar bone or prosthetic crowns. The dental pulp spaces are best seen at the level of the tooth neck. Pulp and endodontic fillings can be distinguished on ultrasound. PMID:24170803

  4. Dental Therapy: Evolving in Minnesota’s Safety Net

    PubMed Central

    Born, David; Nagy, Amanda

    2014-01-01

    Objectives. We identified Minnesota’s initial dental therapy employers and surveyed dental safety net providers’ perceptions of dental therapy. Methods. In July 2011, we surveyed 32 Minnesota dental safety net providers to assess their prospective views on dental therapy employment options. In October 2013, we used an employment scan to reveal characteristics of the early adopters of dental therapy. Results. Before the availability of licensed dental therapists, safety net dental clinic directors overwhelmingly (77%) supported dental therapy. As dental therapists have become licensed over the past 2 years, the early employers of dental therapists are safety net clinics. Conclusions. Although the concept of dental therapy remains controversial in Minnesota, it now has a firm foundation in the state’s safety net clinics. Dental therapists are being used in innovative and diverse ways, so, as dental therapy continues to evolve, further research to identify best practices for incorporating dental therapists into the oral health care team is needed. PMID:24825234

  5. [Prosthetic dental alloys. 1].

    PubMed

    Quintero Engelmbright, M A

    1990-11-01

    A wide variety of restoration materials for prosthetic odontology is now available to the dental surgeon, either of the covalent type (acrylic resins), metallic (alloys), ionic (porcelains), or a combination of them, as in the so-called composites, such as the composite resins, or as ceramics-metals mixtures. An example of the latter is a product called Miracle-Mix, a glass ionomere cement reinforced with an amalgam alloy. In those cases where the blend is done by a synterization process, the material is called Cermet. The above-listed alternatives clearly evidence day-to-day advances in odontology, with researchers and manufacturers engaged the world over in improving existing products or developing new ones to enrich the dentist's armamentarium. As a side effect of this constant renewal, those dentists who have failed to update their knowledge fall behind in their practice as they persist in using products they have known for years, and may be deceived by advertisements of too-often unreliable products. It is, therefore, important to be aware of available products and their latest improvements. PMID:2132464

  6. [Prosthetic dental alloys (2)].

    PubMed

    Quintero Englembright, M A

    1990-12-01

    A wide variety of restoration materials for prosthetic odontology is now available to the dental surgeon, either of the covalent type (acrylic resins), metallic (alloys), ionic (porcelains), or a combination of them, as in the so-called composites, such as the composite resins, or as ceramics-metals mixtures. An example of the latter is a product called Miracle-Mix, a glass ionomere cement reinforced with an amalgam alloy. In those cases where the blend is done by a synterization process, the material is called Cermet. The above-listed alternatives clearly evidence day-to-day advances in odontology, with researchers and manufacturers engaged the world over in improving existing products or developing new ones to enrich the dentist's armamentarium. As a side effect of this constant renewal, those dentists who have failed to update their knowledge fall behind in their practice as they persist in using products they have known for years, and may be deceived by advertisements of too-often unreliable products. It is, therefore, important to be aware of available products and their latest improvements. PMID:2132470

  7. Sealants and dental caries

    PubMed Central

    O’Donnell, Jean A.; Modesto, Adriana; Oakley, Marnie; Polk, Deborah E.; Valappil, Benita; Spallek, Heiko

    2013-01-01

    Background The authors conducted a qualitative study of private-practice dentists in their offices by using vignette-based interviews to assess barriers to the use of evidence-based clinical recommendations in the treatment of noncavitated carious lesions. Methods The authors recruited 22 dentists as a convenience sample and presented them with two patient vignettes involving noncavitated carious lesions. Interviewers asked participants to articulate their thought processes as they described treatment recommendations. Participants compared their treatment plans with the American Dental Association’s recommendations for sealing noncavitated carious lesions, and they described barriers to implementing these recommendations in their practices. The authors recorded and transcribed the sessions for accuracy and themes. Results Personal clinical experience emerged as the determining factor in dentists’ treatment decisions regarding noncavitated carious lesions. Additional factors were lack of reimbursement and mistrust of the recommendations. The authors found that knowledge of the recommendations did not lead to their adoption when the recommendation was incongruent with the dentist’s personal experience. Conclusions The authors found that ingrained practice behavior based on personal clinical experience that differed substantially from evidence-based recommendations resulted in a rejection of these recommendations. Practical Implications Attempts to improve the adoption of evidence-based practice must involve more than simple dissemination of information to achieve a balance between personal clinical experience and scientific evidence. PMID:23543700

  8. Dental Care for Medicaid and CHIP Enrollees

    MedlinePlus

    ... Reports and Evaluations Basic Health Program State Resources Innovation Accelerator Program Medicaid State Technical Assistance Medicaid and ... Individual State Reports ADA Guide to Medicaid Dental Innovations AAPD State EPSDT Dental Periodicity Schedules State Medicaid ...

  9. American Academy of Dental Sleep Medicine

    MedlinePlus

    ... ProSomnus Sleep Technologies Nierman Practice Management ResMed SML-Space Maintainers Laboratory ... Copyright © American Academy of Dental Sleep Medicine, All Rights Reserved. American Academy of Dental Sleep ...

  10. 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)

  11. FastStats: Oral and Dental Health

    MedlinePlus

    ... What's this? Submit Button NCHS Home Oral and Dental Health Recommend on Facebook Tweet Share Compartir Data ... States, 2015, table 60 [PDF - 9.8 MB] Dental visits Percent of children aged 2-17 with ...

  12. 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

  13. Dental care utilization over time.

    PubMed

    Beazoglou, T; Brown, L J; Heffley, D

    1993-12-01

    Between 1950 and 1978, per capita real dental expenditures in the U.S. grew at an average annual rate of 3.33%. Between 1978 and 1989 there was virtually no net growth in this measure of dental care utilization. This sharp curtailment of utilization growth has promoted debate about the sources of this change. Possible explanations include, among others, a reduction in dental disease due to increased exposure to fluoridation, the substitution of noncaloric sweeteners for refined sugar, preventive dentistry, , improved oral health habits, an increase in the net price of dental services, and the cost-containment efforts of insurers and employers. Changes have occurred in all of these variables, but little has done to isolate and quantify the individual effects. This decomposition is difficult, in part, because of the lack of an established model for time-series analysis of dental care utilization. A model of dental care demand, incorporating economic factors (out-of-pocket or net dental prices, per capita income, and nondental prices) as well as dietary factors (refined sugar consumption, noncaloric sweeteners, and exposure to fluoridated water), is combined with a simple model of dental care supply within an equilibrium framework. A two-stage estimation procedure is applied, using U.S. aggregate time-series data for the period 1950-89. Results show that economic and dietary factors are significantly related to changes in utilization. Net price and income elasticities of demand exhibit the expected signs and are compatible with estimates from cross-sectional studies. Decreases in cane and beet sugar consumption, facilitated by the increase in the use of noncaloric sweeteners, are associated with reductions in utilization. Fluoridation appears to be weakly but positively related to utilization. There also appears to have been a significant structural shift in demand since 1978. Overall goodness-of-fit is strong and the model accurately tracks the 1978-89 flattening of

  14. Salivary biomarkers for dental caries.

    PubMed

    Gao, Xiaoli; Jiang, Shan; Koh, David; Hsu, Chin-Ying Stephen

    2016-02-01

    As a highly prevalent multifactorial disease, dental caries afflicts a large proportion of the world's population. As teeth are constantly bathed in saliva, the constituents and properties of this oral fluid play an essential role in the occurrence and progression of dental caries. Various inorganic (water and electrolytes) and organic (proteins and peptides) components may protect teeth from dental caries. This occurs via several functions, such as clearance of food debris and sugar, aggregation and elimination of microorganisms, buffering actions to neutralize acid, maintaining supersaturation with respect to tooth mineral, participation in formation of the acquired pellicle and antimicrobial defense. Modest evidence is available on the associations between dental caries and several salivary parameters, including flow rate, buffering capacity and abundance of mutans streptococci. Despite some controversial findings, the main body of the literature supports an elevated caries prevalence and/or incidence among people with a pathologically low saliva flow rate, compromised buffering capacity and early colonization or high titer of mutans streptococci in saliva. The evidence remains weak and/or inconsistent on the association between dental caries and other saliva parameters, such as other possible cariogenic species (Lactobacillus spp., Streptococcus sanguis group, Streptococcus salivarius, Actinomyces spp. and Candida albicans), diversity of saliva microbiomes, inorganic and organic constituents (electrolytes, immunoglobulins, other proteins and peptides) and some functional properties (sugar clearance rate, etc.). The complex interactions between salivary components and functions suggest that saliva has to be considered in its entirety to account for its total effects on teeth. PMID:26662487

  15. Belongingness in undergraduate dental education.

    PubMed

    Radford, D R; Hellyer, P

    2016-05-27

    Objective To undertake a detailed educational evaluation into dental students' experience of the concept of belongingness and their development as 'safe beginners' on an outreach placement at the University of Portsmouth Dental Academy (UPDA).Method The participants were asked two questions: Did you feel belongingness at UPDA?; and When in your year rotation did you feel this? They completed the educational evaluation anonymously in their last week of attendance. The quantitative data was handled with descriptive statistics and the qualitative data was analysed for recurring themes.Results A 95% response rate was achieved. Eighty six percent of respondents strongly agreed to feeling belongingness and 56% felt it after their first two weeks. Four themes were identified: 'Interaction with the preexisting people environment' (1a. Initial welcoming and warmth 1b. Continued interest in me as an individual); 'Developing collegiality' (2a. My group of fellow students 2b. Working with the dental team as a dentist 2c. The team of everyone at UPDA); 'In the clinical environment' (3a. Being a dentist with responsibility and respect 3b. The physical environment 3c. Becoming a reflective independent practitioner); and 'Leadership'.Conclusion Belongingness in dental education should be defined as:- a deeply personal and contextually mediated experience in which a student becomes an essential and respected part of the dental educational environment where all are accepted and equally valued by each other and which allows each individual student to develop autonomy, self-reflection and self-actualisation as a clinician. PMID:27228935

  16. [Websites of dental practices evaluated].

    PubMed

    Poorterman, J H G; Tjiook, S P; Moeijes, S F S; Brand, H S

    2014-05-01

    In 2013, a dental practice without a website is almost unthinkable. Using a sample of309 dentists drawn from the list of members of the Dutch Dental Association in 2012, a study was carried out to find out whether the dental practice of the general dental practitioner had a website. The content of each website was subsequently inventoried using a questionnaire. Eighty-nine percent of the dental practices had a website. The content of the websites, however, varied enormously. An element such as the professional registration number with a reference to the professional register were absent in 73% of the websites and the date of the most recent update of the website was mentioned only once. The name of the dentist, his or her professional qualification and an email address were missing on respectively 9%, 20% and 9% of the websites. Contracts of the practice with insurance companies were rarely clearly indicated. The websites of many practices would benefit considerably from a significant improvement. PMID:24881254

  17. 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

  18. 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…

  19. 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…

  20. Reforming the mission of public dental services.

    PubMed

    Wright, F A C; List, P F

    2012-10-01

    Australia has a complex history of providing public dental services to its communities. From the early days of Colonial settlement, the provision of dental care to the Australian public has largely been driven and influenced by organized groups and associations of dentists. The Constitution of Australia, under Section 51 xxiii A, allows for the Commonwealth to provide for medical and dental services. Unlike the United Kingdom, however, dental services have not been embedded into a universal national health service agenda. In 1974, that the Australian Government through the Australian School Dental Program provided the first funding and national direction for public dental services - and that, limited to children. The Commonwealth Dental Health Program 1993-1997 was the second national endeavor to provide public dental services, this time to financially disadvantaged adults. Since that time, public dental service responsibility has been shuttled between States/Territories and the Commonwealth. A new paradigm for public dental services in Australia requires strong Commonwealth leadership, as well as the commitment of State and Territories and the organized dental profession. The National Health and Hospitals Reform Commission provided the most recent scenario for a radical change in mission. This paper canvases the competing roles of strategic, functional, and structural issues in relationship to social network and policy issues, which must be recognized if Australians truly seek to reform public dental services. PMID:22998313

  1. 21 CFR 868.5820 - Dental protector.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Dental protector. 868.5820 Section 868.5820 Food... DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5820 Dental protector. (a) Identification. A dental protector is a device intended to protect a patient's teeth during manipulative procedures...

  2. 21 CFR 868.5820 - Dental protector.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Dental protector. 868.5820 Section 868.5820 Food... DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5820 Dental protector. (a) Identification. A dental protector is a device intended to protect a patient's teeth during manipulative procedures...

  3. 42 CFR 440.100 - Dental services.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 4 2013-10-01 2013-10-01 false Dental services. 440.100 Section 440.100 Public...) MEDICAL ASSISTANCE PROGRAMS SERVICES: GENERAL PROVISIONS Definitions § 440.100 Dental services. (a) “Dental services” means diagnostic, preventive, or corrective procedures provided by or under...

  4. 42 CFR 440.100 - Dental services.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 4 2014-10-01 2014-10-01 false Dental services. 440.100 Section 440.100 Public...) MEDICAL ASSISTANCE PROGRAMS SERVICES: GENERAL PROVISIONS Definitions § 440.100 Dental services. (a) “Dental services” means diagnostic, preventive, or corrective procedures provided by or under...

  5. 38 CFR 52.170 - Dental services.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Dental services. 52.170... FOR ADULT DAY HEALTH CARE OF VETERANS IN STATE HOMES Standards § 52.170 Dental services. (a) Program... (2) By arranging for transportation to and from the dental services. (b) Program management...

  6. 38 CFR 52.170 - Dental services.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2011-07-01 2011-07-01 false Dental services. 52.170... FOR ADULT DAY HEALTH CARE OF VETERANS IN STATE HOMES Standards § 52.170 Dental services. (a) Program... (2) By arranging for transportation to and from the dental services. (b) Program management...

  7. 42 CFR 483.55 - Dental services.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 5 2012-10-01 2012-10-01 false Dental services. 483.55 Section 483.55 Public... Care Facilities § 483.55 Dental services. The facility must assist residents in obtaining routine and 24-hour emergency dental care. (a) Skilled nursing facilities. A facility (1) Must provide or...

  8. 38 CFR 52.170 - Dental services.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2012-07-01 2012-07-01 false Dental services. 52.170... FOR ADULT DAY HEALTH CARE OF VETERANS IN STATE HOMES Standards § 52.170 Dental services. (a) Program... (2) By arranging for transportation to and from the dental services. (b) Program management...

  9. 42 CFR 483.55 - Dental services.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 5 2013-10-01 2013-10-01 false Dental services. 483.55 Section 483.55 Public... Care Facilities § 483.55 Dental services. The facility must assist residents in obtaining routine and 24-hour emergency dental care. (a) Skilled nursing facilities. A facility (1) Must provide or...

  10. 42 CFR 483.55 - Dental services.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 5 2014-10-01 2014-10-01 false Dental services. 483.55 Section 483.55 Public... Care Facilities § 483.55 Dental services. The facility must assist residents in obtaining routine and 24-hour emergency dental care. (a) Skilled nursing facilities. A facility (1) Must provide or...

  11. 42 CFR 440.100 - Dental services.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 4 2012-10-01 2012-10-01 false Dental services. 440.100 Section 440.100 Public...) MEDICAL ASSISTANCE PROGRAMS SERVICES: GENERAL PROVISIONS Definitions § 440.100 Dental services. (a) “Dental services” means diagnostic, preventive, or corrective procedures provided by or under...

  12. 38 CFR 52.170 - Dental services.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2014-07-01 2014-07-01 false Dental services. 52.170... FOR ADULT DAY HEALTH CARE OF VETERANS IN STATE HOMES Standards § 52.170 Dental services. (a) Program... (2) By arranging for transportation to and from the dental services. (b) Program management...

  13. 21 CFR 868.5820 - Dental protector.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Dental protector. 868.5820 Section 868.5820 Food... DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5820 Dental protector. (a) Identification. A dental protector is a device intended to protect a patient's teeth during manipulative procedures...

  14. 21 CFR 868.5820 - Dental protector.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Dental protector. 868.5820 Section 868.5820 Food... DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5820 Dental protector. (a) Identification. A dental protector is a device intended to protect a patient's teeth during manipulative procedures...

  15. 21 CFR 868.5820 - Dental protector.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Dental protector. 868.5820 Section 868.5820 Food... DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5820 Dental protector. (a) Identification. A dental protector is a device intended to protect a patient's teeth during manipulative procedures...

  16. 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…

  17. 38 CFR 52.170 - Dental services.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2013-07-01 2013-07-01 false Dental services. 52.170... FOR ADULT DAY HEALTH CARE OF VETERANS IN STATE HOMES Standards § 52.170 Dental services. (a) Program... (2) By arranging for transportation to and from the dental services. (b) Program management...

  18. DENTAL REIMBURSEMENT PROGRAM (DPR) - HIV/AIDS

    EPA Science Inventory

    The Dental Reimbursement Program (DPR) under Part F of the Ryan White CARE Act is intended to help accredited dental schools and post-doctoral dental education program cover their non-reimbursed costs of providing oral health care to individuals with HIV.

  19. 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…

  20. 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…

  1. Predictive Validity of the Dental Admission Test.

    ERIC Educational Resources Information Center

    Kramer, Gene A.

    1986-01-01

    The relationship of Dental Admission Test (DAT) scales and predental grade point averages with freshman and sophomore dental school performance measures and National Board Dental Examination (NBDE) Part I averages were examined. The results indicated that the DAT scales had limited predictive validity. (Author/MLW)

  2. Women Dental Students: Preferences in Support Services.

    ERIC Educational Resources Information Center

    Austin, Grace; Tenzer, Amy

    1980-01-01

    Female dental students in 68 American and Canadian dental schools were surveyed regarding women in dental school. It was found that almost 80 percent do not believe their sex hinders them, that qualifications should be the primary consideration in admission and hiring, and that special seminars would be a beneficial support service. (JSR)

  3. 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. PMID:26982756

  4. 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. PMID:12699234

  5. Dental health in Malaysia.

    PubMed

    Majid, Z A

    1984-12-01

    Three epidemiological surveys have been carried out in Malaysia since 1971. All showed a high level of caries prevalence. Ninety per cent of school children between the ages of 6 and 18 suffered from dental caries, with a DMFT of approximately 3 and a dft of approximately 2. Ninety-five per cent of the adult population had caries experience, with the mean DMFT being 13.2. Approximately 55 per cent of children showed the presence of gingivitis with the mean number of inflamed gingival units per child ranging from 1.9 to 2.8, while 72.4 per cent of adults had some form of periodontal disease with 29 per cent having pockets deeper than 3 mm. The OHI-S score for adults was 2.2 and 81 per cent used toothbrushes to clean their teeth. A further 5.1 per cent used twigs and fingers with powdered charcoal or salt. One-third of the child population needed orthodontic treatment, with 0.3 per cent examined in peninsular Malaysia having cleft lip or palate or both. In the adult population 10.4 per cent of those examined required some form of orthodontic treatment. Twenty per cent of the children in the survey were in need of dentures; 54.7 per cent of the adults were either in need of dentures or were wearing dentures. Of these 25 per cent had complete dentures. The smoking habit was most commonly associated with pre-cancerous/cancerous lesions with alcohol consumption a close competitor; 114 adults, that is 1.3 per cent of those examined, suffer from leukoplakia but only one case of oral cancer was detected.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:6597132

  6. [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. PMID:26878713

  7. 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

  8. Comparative evaluation of effects of bleaching on color stability and marginal adaptation of discolored direct and indirect composite laminate veneers under in vivo conditions

    PubMed Central

    Jain, Veena; Das, Taposh K.; Pruthi, Gunjan; Shah, Naseem; Rajendiran, Suresh

    2015-01-01

    Statement of Problem: Change in color and loss of marginal adaptation of tooth colored restorative materials is not acceptable. Bleaching is commonly used for treating discolored teeth. However, the literature is scanty regarding its effect on color and marginal adaptation of direct and indirect composite laminate veneers (CLVs) under in vivo conditions. Purpose: Purpose of the study was to determine the effect of bleaching on color change and marginal adaptation of direct and indirect CLVs over a period of time when exposed to the oral environment. Materials and Methods: For this purpose, a total of 14 subjects irrespective of age and sex indicated for CLV restorations on maxillary anterior teeth were selected following the inclusion and exclusion criteria. For each subject, indirect CLVs were fabricated and looted in the first quadrant (Group 1) and direct CLV's (Group 2), were given in the second quadrant. Color change was assessed clinically using intra-oral digital spectrophotometer and marginal adaptation was assessed on epoxy resin replica of the tooth-restoration interface under scanning electron microscope. After 6 months, the subjects underwent a home bleaching regimen for 14 days using 10% carbamide peroxide. The assessment of color change and marginal adaptation was done at 6 months after veneering (0–180 days), immediately after the bleaching regimen (0–194 days) and 3 months after the bleaching regimen (0–284 days). Results: The difference in median color change (ΔE) between the groups was tested using Wilcoxon rank sum test while the median color change with time within the groups was tested using Wilcoxon signed rank test. The difference in the rates of marginal adaptation was tested between the groups using Chi-square/Fisher's exact test. Bleaching led to statistically significant color change at cervical (CE), middle and incisal (IE) regions when direct and indirect composites were compared (P < 0.05). During intra-group comparison, direct

  9. Facial and Dental Injuries Facial and Dental Injuries in Karate.

    PubMed

    Vidovic-Stesevic, Vesna; Verna, Carlalberta; Krastl, Gabriel; Kuhl, Sebastian; Filippi, Andreas

    2015-01-01

    Karate is a martial art that carries a high trauma risk. Trauma-related Swiss and European karate data are currently unavailable. This survey seeks to increase knowledge of the incidence of traumatic facial and dental injuries, their emergency management, awareness of tooth rescue boxes, the use of mouthguards and their modifications. Interviews were conducted with 420 karate fighters from 43 European countries using a standardized questionnaire. All the participants were semi-professionals. The data were evaluated with respect to gender, kumite level (where a karate practitioner trains against an adversary), and country. Of the 420 fighters interviewed, 213 had experienced facial trauma and 44 had already had dental trauma. A total of 192 athletes had hurt their opponent by inflicting a facial or dental injury, and 290 knew about the possibility of tooth replantation following an avulsion. Only 50 interviewees knew about tooth rescue boxes. Nearly all the individuals interviewed wore a mouthguard (n = 412), and 178 of them had made their own modifications to the guard. The results of the present survey suggest that more information and education in wearing protective gear are required to reduce the incidence of dental injuries in karate. PMID:26345152

  10. The National Institute of Dental Research Clinical Dental Staff Fellowship.

    ERIC Educational Resources Information Center

    Baum, Bruce J.; And Others

    1988-01-01

    A program in one of the National Institutes of Health offers clinical training fellowships as a means of training potential dental school faculty by providing both unique clinical skills and high-quality research experience. The program was developed in response to a perceived need for change in academic dentistry. (MSE)

  11. 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.…

  12. Effects of Early Dental Office Visits on Dental Caries Experience

    PubMed Central

    Rozier, R. Gary; Preisser, John S.; Stearns, Sally C.; Lee, Jessica Y.

    2014-01-01

    Objectives. We determined the association between timing of a first dentist office visit before age 5 years and dental disease in kindergarten. Methods. We used North Carolina Medicaid claims (1999–2006) linked to state oral health surveillance data to compare caries experience for kindergarten students (2005–2006) who had a visit before age 60 months (n = 11 394) to derive overall exposure effects from a zero-inflated negative binomial regression model. We repeated the analysis separately for children who had preventive and tertiary visits. Results. Children who had a visit at age 37 to 48 and 49 to 60 months had significantly less disease than children with a visit by age 24 months (incidence rate ratio [IRR] = 0.88; 95% confidence interval [CI] = 0.81, 0.95; IRR = 0.75; 95% CI = 0.69, 0.82, respectively). Disease status did not differ between children who had a tertiary visit by age 24 months and other children. Conclusions. Medicaid-enrolled children in our study followed an urgent care type of utilization, and access to dental care was limited. Children at high risk for dental disease should be given priority for a preventive dental visit before age 3 years. PMID:24134364

  13. 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.

  14. [Conventional dental radiography and future prospectives].

    PubMed

    Youssefzadeh, S; Gahleitner, A; Bernhart, D; Bernhart, T

    1999-12-01

    Until recently, conventional dental radiology was performed by dentists and orofacial surgeons. Due to the rapid development of radiological technique, the demand of radiological advice is increasing. The radiologists see more and more dental patients in their daily routine. The aim of this article is to give an overview on established dental radiology and a glimpse into the future. Conventional dental radiology and digital radiography are presently in use. Intraoral technique comprises dental films, bite-wing views and occlusal radiographs. Panoramic views and cephalometric radiographs are done with extraoral technique. Digital radiography lacks all processes in behalf of film development. It leads to dose reduction and enables image manipulation. PMID:10643025

  15. Dental standards: fifty years of development.

    PubMed

    Jones, D W

    2012-09-01

    Dental standards play a vital and important role in society by contributing to the quality and safety levels of products used in dental treatments by dental professionals as well as the hygiene products used by the general public. Few members of the public or indeed many dentists fully appreciate the contribution made by ISO international dental standards to the safety and quality of dental care. Further more the United Kingdom played a significant role in the establishment of the international standards organisation (ISO). The first two meetings of the dental international standards committee took place in England. In this article Derek W. Jones outlines the significant and important role played by the UK during the fifty years of dental international standards. PMID:22996480

  16. Factors for increasing adoption of e-courses among dental and dental hygiene faculty members.

    PubMed

    DeBate, Rita D; Cragun, Deborah; Severson, Herbert H; Shaw, Tracy; Christiansen, Steve; Koerber, Anne; Tomar, Scott; Brown, Kelli McCormack; Tedesco, Lisa A; Hendricson, William

    2011-05-01

    The incorporation of web-based learning into the dental curriculum has been consistently recommended in the literature on reform in dental education. There has been growing support for web-based learning in dental and dental hygiene education as demonstrated by deans' identifying this as a planned curricular innovation. The purpose of our study was to explore characteristics of e-courses that may serve to increase adoption among dental and dental hygiene faculty members. Eight ninety-minute focus groups (three dental; five dental hygiene) were conducted with dental (n=27) and dental hygiene (n=23) faculty members from six academic institutions. The resulting data were analyzed to identify two overarching themes and associated subthemes with regard to benefits and barriers influencing adoption of e-courses. A working conceptual framework, based on the Diffusion of Innovations, was developed from these themes to understand the characteristics that may influence the rate of adoption of e-courses among dental and dental hygiene faculty members. Analysis of the data revealed four main adoption barriers: 1) low perceived relative advantage to faculty members; 2) low compatibility with current curriculum; 3) high perceived time commitment; and 4) complexity of e-course development. This exploratory assessment identifies leverage points for facilitating the adoption and sustainability of e-courses in dental and dental hygiene education. PMID:21546592

  17. Symposium on Dental Health Behavior.

    ERIC Educational Resources Information Center

    Green, Lawrence W., Ed.; And Others

    1974-01-01

    This document presents papers, critiques, and comments from a symposium which assessed the current status of preventive dental behavior. The field was divided into the following three major areas: (a) mass media programs, (b) school health programs, and (c) effect of the private practitioner. Each author was asked to review the literature, provide…

  18. Concerns of Entering Dental Students.

    ERIC Educational Resources Information Center

    Sachs, Robert H.; And Others

    1981-01-01

    First-year dental students from three schools were surveyed to assess their concern about psychosocial, academic, time, isolation, and money issues. Similarity in ranking of concerns, and differences in intensity of concern are examined for implications for research in stress management. (MSE)

  19. 76 FR 14600 - Dental Conditions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-17

    ... disability adjudicated as resulting from combat wounds or service trauma (Class II(a)). Who are homeless or... there is dental disability due to combat wounds or service trauma. To determine prisoner of war status..., the rating activity will determine whether the condition is due to combat or other in-service...

  20. 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…

  1. 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…

  2. 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) "Visiting the…

  3. 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…

  4. Trends in Dental Educators' Salaries.

    ERIC Educational Resources Information Center

    Solomon, Eric S.

    1992-01-01

    An examination of national data on dental educators' salaries since 1975 compares average salaries for basic and clinical science faculty, relates faculty salaries to changes in the Consumer Price Index (since 1976), and tracks faculty salaries in constant dollars. A brief analysis of results accompanies data graphs. (MSE)

  5. 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,…

  6. Denitrification in human dental plaque

    PubMed Central

    2010-01-01

    Background Microbial denitrification is not considered important in human-associated microbial communities. Accordingly, metabolic investigations of the microbial biofilm communities of human dental plaque have focused on aerobic respiration and acid fermentation of carbohydrates, even though it is known that the oral habitat is constantly exposed to nitrate (NO3-) concentrations in the millimolar range and that dental plaque houses bacteria that can reduce this NO3- to nitrite (NO2-). Results We show that dental plaque mediates denitrification of NO3- to nitric oxide (NO), nitrous oxide (N2O), and dinitrogen (N2) using microsensor measurements, 15N isotopic labelling and molecular detection of denitrification genes. In vivo N2O accumulation rates in the mouth depended on the presence of dental plaque and on salivary NO3- concentrations. NO and N2O production by denitrification occurred under aerobic conditions and was regulated by plaque pH. Conclusions Increases of NO concentrations were in the range of effective concentrations for NO signalling to human host cells and, thus, may locally affect blood flow, signalling between nerves and inflammatory processes in the gum. This is specifically significant for the understanding of periodontal diseases, where NO has been shown to play a key role, but where gingival cells are believed to be the only source of NO. More generally, this study establishes denitrification by human-associated microbial communities as a significant metabolic pathway which, due to concurrent NO formation, provides a basis for symbiotic interactions. PMID:20307293

  7. 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…

  8. 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…

  9. 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…

  10. Gold color in dental alloys.

    PubMed

    Cameron, T

    1997-01-01

    This article will help the dental laboratory with alloy selection by exploring how the relationship among color, ductility and strength applies to gold and how color can be quantified. Because higher quality materials translate into higher profits, upselling to the dentist and patient is also discussed. PMID:9524484

  11. Some thoughts on dental malpractice.

    PubMed

    Morris, W O

    1976-06-01

    Malpractice litigation is not new nor is it limited to the professions of medicine and dentistry. The number of dental malpractice claims is increasing in many countries though the percentage of cases in which the patient succeeds remains constant at about ten to twelve per cent. In successful cases however the monetary compensation awarded has increased substantially in the past few years. The increasing use of multi-chair dental offices and the employment of more auxiliary workers in dental practice may have contributed to the increase in litigation as has the widespread dissemination of knowledge of patients' rights by newspapers and television. It is unfair to blame the legal profession for this increase. There is evidence that the 'contingent fee' arrangement between plantiff and lawyer contributes to the number of cases brought. It has been suggested that the existence of malpractice insurance may make the dentist less careful to prevent untoward effects of dental treatment. In many states the law will not permit punitive damages to be paid by the insurance agency nor are fines imposed for criminal activities covered. It is important that the dentist should be fully informed about the details of the cover which his insurance does in fact provide. PMID:1067226

  12. 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. PMID:25662163

  13. On the reporting of dental health, time for dental care, and the treatment panorama.

    PubMed

    Swedberg, Y

    1999-01-01

    The thesis included five methodological studies and one caries epidemiological investigation, the general aim being to study how to measure and report dental health, time for dental care, treatment panorama, and dental care outcomes, within a Public Dental Service organization. The specific aims were to monitor dental clinic activities using a time study method, to apply time study results of a dental health-related patient group system for the 3-19 year age groups, and to compare time study results with corresponding results from computerized systems used for reporting dental care. Other specific aims were to compare longitudinal caries index data results between cohort and cross-sectional samples, to analyse caries index for extreme caries groups among adolescents leaving organized dental care, and--using time series methods--to analyse dental health development of the 15-19 year age groups. Results from the time studies portrayed the dental clinic as a working unit, showed that reported values can represent dental care only for intervention procedures, and indicated that clinic patterns were not adapted to the health situation of the patient groups. Longitudinal cohort attempts gave different values from those of the cross-sectional year classes, which should be the primary focus when presenting caries index mean values in dental health reviews. Caries-free groups from 15 to 19 years of age seem to be stable in their caries development in about 60%-80% of cases; while the 20% groups with the highest index values accounted for about 80% of all approximal lesions. In times of major economic adjustment, dental health for adolescents in Göteborg was an example of sustainable dental health development. A model system for monitoring, analysing, and reporting dental health and dental care outcomes within a dental care-giving organization calls for several conditions, for example, a dental health-related patient group system, and a rationale for the choice of dental

  14. 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…

  15. 21 CFR 872.2050 - Dental sonography device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.2050 Dental sonography device. (a) Dental sonography device for monitoring—(1) Identification. A dental sonography device for monitoring is an... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Dental sonography device. 872.2050 Section...

  16. 21 CFR 872.2050 - Dental sonography device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.2050 Dental sonography device. (a) Dental sonography device for monitoring—(1) Identification. A dental sonography device for monitoring is an... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Dental sonography device. 872.2050 Section...

  17. 38 CFR 17.160 - Authorization of dental examinations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2013-07-01 2013-07-01 false Authorization of dental... MEDICAL Dental Services § 17.160 Authorization of dental examinations. When a detailed report of dental examination is essential for a determination of eligibility for benefits, dental examinations may...

  18. 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...

  19. 38 CFR 17.163 - Posthospital outpatient dental treatment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... dental treatment. 17.163 Section 17.163 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS MEDICAL Dental Services § 17.163 Posthospital outpatient dental treatment. The Chief, Dental Service may authorize outpatient dental care which is reasonably necessary to complete treatment of...

  20. 38 CFR 17.163 - Posthospital outpatient dental treatment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... dental treatment. 17.163 Section 17.163 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS MEDICAL Dental Services § 17.163 Posthospital outpatient dental treatment. The Chief, Dental Service may authorize outpatient dental care which is reasonably necessary to complete treatment of...

  1. 38 CFR 17.160 - Authorization of dental examinations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2012-07-01 2012-07-01 false Authorization of dental... MEDICAL Dental Services § 17.160 Authorization of dental examinations. When a detailed report of dental examination is essential for a determination of eligibility for benefits, dental examinations may...

  2. 38 CFR 17.163 - Posthospital outpatient dental treatment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... dental treatment. 17.163 Section 17.163 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS MEDICAL Dental Services § 17.163 Posthospital outpatient dental treatment. The Chief, Dental Service may authorize outpatient dental care which is reasonably necessary to complete treatment of...

  3. 21 CFR 872.2050 - Dental sonography device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Dental sonography device. 872.2050 Section 872...) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.2050 Dental sonography device. (a) Dental sonography device for monitoring—(1) Identification. A dental sonography device for monitoring is...

  4. 38 CFR 17.163 - Posthospital outpatient dental treatment.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... dental treatment. 17.163 Section 17.163 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS MEDICAL Dental Services § 17.163 Posthospital outpatient dental treatment. The Chief, Dental Service may authorize outpatient dental care which is reasonably necessary to complete treatment of...

  5. 21 CFR 872.2050 - Dental sonography device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Dental sonography device. 872.2050 Section 872...) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.2050 Dental sonography device. (a) Dental sonography device for monitoring—(1) Identification. A dental sonography device for monitoring is...

  6. 38 CFR 17.160 - Authorization of dental examinations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2014-07-01 2014-07-01 false Authorization of dental... MEDICAL Dental Services § 17.160 Authorization of dental examinations. When a detailed report of dental examination is essential for a determination of eligibility for benefits, dental examinations may...

  7. 38 CFR 17.163 - Posthospital outpatient dental treatment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... dental treatment. 17.163 Section 17.163 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS MEDICAL Dental Services § 17.163 Posthospital outpatient dental treatment. The Chief, Dental Service may authorize outpatient dental care which is reasonably necessary to complete treatment of...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 21 CFR 872.2050 - Dental sonography device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.2050 Dental sonography device. (a) Dental sonography device for monitoring—(1) Identification. A dental sonography device for monitoring is an... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Dental sonography device. 872.2050 Section...

  13. 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,…

  14. Surface modification with alumina blasting and H2SO4-HCl etching for bonding two resin-composite veneers to titanium.

    PubMed

    Taira, Yohsuke; Egoshi, Takafumi; Kamada, Kohji; Sawase, Takashi

    2014-02-01

    The purpose of this study was to investigate the effect of an experimental surface treatment with alumina blasting and acid etching on the bond strengths between each of two resin composites and commercially pure titanium. The titanium surface was blasted with alumina and then etched with 45wt% H2SO4 and 15wt% HCl (H2SO4-HCl). A light- and heat-curing resin composite (Estenia) and a light-curing resin composite (Ceramage) were used with adjunctive metal primers. Veneered specimens were subjected to thermal cycling between 4 and 60°C for 50,000 cycles, and the shear bond strengths were determined. The highest bond strengths were obtained for Blasting/H2SO4-HCl/Estenia (30.2 ± 4.5 MPa) and Blasting/Etching/Ceramage (26.0 ± 4.5 MPa), the values of which were not statistically different, followed by Blasting/No etching/Estenia (20.4 ± 2.4 MPa) and Blasting/No etching/Ceramage (0.8 ± 0.3 MPa). Scanning electron microscopy observations revealed that alumina blasting and H2SO4-HCl etching creates a number of micro- and nanoscale cavities on the titanium surface, which contribute to adhesive bonding. PMID:24372961

  15. 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

  16. 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. PMID:25465981

  17. 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

  18. 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. PMID:24502052

  19. Dental Management of Patients with Dementia in Primary Dental Care.

    PubMed

    Moosajee, Sukina; Rafique, Sobia; Daly, Blánaid

    2015-05-01

    Dementia is an umbrella term for a set of symptoms that include memory loss, changes in mood and problems with reasoning, attention and communication. It is a progressive condition and there is ample evidence that oral health declines as the severity of dementia increases. Most of this decline is attributable to the effects of cognitive impairment on oral hygiene capability and/or acceptance of help from others in supporting oral hygiene. Factors such as altered salivary flow, taste change, use of high-energy food supplements and syrup-based medications also contribute to the risk of oral and dental diseases. In its role as part of the wider health and social care network, the primary dental care team can make an important contribution to securing the oral health of people living with dementia. PMID:26556259

  20. 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

  1. [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. PMID:20481107

  2. Determination of the slow crack growth susceptibility coefficient of dental ceramics using different methods.

    PubMed

    Gonzaga, Carla Castiglia; Cesar, Paulo Francisco; Miranda, Walter Gomes; Yoshimura, Humberto Naoyuki

    2011-11-01

    This study compared three methods for the determination of the slow crack growth susceptibility coefficient (n) of two veneering ceramics (VM7 and d.Sign), two glass-ceramics (Empress and Empress 2) and a glass-infiltrated alumina composite (In-Ceram Alumina). Discs (n = 10) were prepared according to manufacturers' recommendations and polished. The constant stress-rate test was performed at five constant stress rates to calculate n(d) . For the indentation fracture test to determine n(IF) , Vickers indentations were performed and the crack lengths were measured under an optical microscope. For the constant stress test (performed only for d.Sign for the determination of n(s) ) four constant stresses were applied and held constant until the specimens' fracture and the time to failure was recorded. All tests were performed in artificial saliva at 37°C. The n(d) values were 17.2 for Empress 2, followed by d.Sign (20.5), VM7 (26.5), Empress (30.2), and In-Ceram Alumina (31.1). In-Ceram Alumina and Empress 2 showed the highest n(IF) values, 66.0 and 40.2, respectively. The n(IF) values determined for Empress (25.2), d.Sign (25.6), and VM7 (20.1) were similar. The n(s) value determined for d.Sign was 31.4. It can be concluded that the n values determined for the dental ceramics evaluated were significantly influenced by the test method used. PMID:21714087

  3. 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.

  4. Dental outpatients: health locus of control correlates.

    PubMed

    Ludenia, K; Donham, G W

    1983-11-01

    Examined relationships between the Multidimensional Health Locus of Control (MHLC) Scales, Beck Depression Inventory, Trait subscales of the State-Trait Personality Inventory, and dental ratings of oral hygiene and presence of periodontal disease with dental outpatients (N = 101) at a Veterans Administration Medical Center Dental Clinic. Results indicated that this sample of outpatients scored comparably on MHLC Health Internality and Health Externality to a sample reported by Wallston and Wallston. Older dental patients, in the present sample, scored significantly higher on Powerful Others Externality in contrast to younger Ss, which suggests greater reliance on health professionals for dental health. Confirmatory evidence is presented on the negative correlations of depression, anger, and anxiety with Health Internality. Differential approaches to dental treatment are discussed. PMID:6662936

  5. Critical appraisal: dental amalgam update--part II: biological effects.

    PubMed

    Wahl, Michael J; Swift, Edward J

    2013-12-01

    Dental amalgam restorations have been controversial for over 150 years. In Part I of this Critical Appraisal, the clinical efficacy of dental amalgam was updated. Here in Part II, the biological effects of dental amalgam are addressed. PMID:24320063

  6. Dental infection simulating skin lesion.

    PubMed

    Abuabara, Allan; Schramm, Celso Alfredo; Zielak, João César; Baratto-Filho, Flares

    2012-01-01

    Orocutaneous fistulas or cutaneous sinus, a tract of dental origin, is an uncommon but well-documented condition that usually requires emergency treatment. Such condition may be misdiagnosed by physicians and dentists and may sometimes be confused with bone and skin tumor, osteomyelitis, congenital fistula, salivary gland fistula, pyogenic granuloma, infected cyst, deep mycotic infection, and other pathologies. A case of facial sinus tract that was initially misdiagnosed by a physician as a nonodontogenic lesion is presented. Nonsurgical endodontic therapy was the treatment of choice for this case. Facial cutaneous sinus tracts must be considered of dental origin. Early diagnosis and prompt treatment minimize patient discomfort and esthetic problems, reducing the possibility of further complications such as sepsis and osteomyelitis. PMID:22892779

  7. Industry support for dental education.

    PubMed

    Sudzina, Michael R

    2005-01-01

    The relationships between industry and dental education are multiple and mutually beneficial. Perhaps most prominent are collaboration on research and development of products and technologies and the knowledge and public credibility that accompany them. Industry is also looked to for product and equipment support in schools and increasingly for help with outreach and access programs schools provide for underserved populations. Not as widely recognized, but still quite important, are the programs for support of student research and sharing of management expertise through exchange of board members. A quarter century ago, the relationship between schools and industry was at arm's length. There was a mistrust in schools that feared exposing their students to commercial contact. Today the relationship has evolved into a mutual search for joint benefits with an eye on the future of the profession and its relationship with patients. This is illustrated in the American Dental Education Association Corporate Council. PMID:16350924

  8. Ergonomic applications to dental practice.

    PubMed

    Gupta, Shipra

    2011-01-01

    The term "work-related musculoskeletal disorders (WMSDs)," refers to musculoskeletal disorders to which the work environment contributes significantly, or to musculoskeletal disorders that are made worse or longer lasting by work conditions or workplace risk factors. In recent years, there has been an increase in reporting WMSDs for dental persons. Risk factors of WMSDs with specific reference to dentistry include - stress, poor flexibility, improper positioning, infrequent breaks, repetitive movements, weak postural muscles, prolonged awkward postures and improper adjustment of equipment. Ergonomics is the science of designing jobs, equipment and workplaces to fit workers. Proper ergonomic design is necessary to prevent repetitive strain injuries, which can develop over time and can lead to long-term disability. In this article, 20 strategies to prevent WMSDs in the dental operatory are discussed. PMID:22484877

  9. Neuropathic pain after dental treatment.

    PubMed

    Tınastepe, Neslihan; Oral, Koray

    2013-01-01

    The head and neck regions are the most common sites of the human body to be involved in chronic pain conditions. Neuropathic pain is a chronic pain condition, and refers to all pain initiated or caused by a primary lesion or dysfunction or transitory perturbation in the peripheral or central nervous system (CNS). Trigeminal neuralgia, atypical odontalgia (phantom tooth pain), burning mouth syndrome, traumatic neuropathies, postherpetic neuralgias and complex regional pain syndrome are neuropathic pain conditions in the orofacial region that can be encountered in pain and dental clinics. The majority of the time this problem is misdiagnosed by the dentist, which can lead to unnecessary treatments. These treatments may include endodontic treatment and extraction of the tooth or teeth in the region. In this review, only post-traumatic peripheral pain neuropathies seen after dental treatments will be discussed. PMID:23588863

  10. Tobacco use and dental disease.

    PubMed

    Hart, G T; Brown, D M; Mincer, H H

    1995-04-01

    The previously cited Indiana University School of Dentistry teaching monograph, "The Impact of Tobacco Use and Cessation on Nonmalignant and Precancerous Oral and Dental Diseases and Conditions," reviewed over 800 articles and concluded that tobacco use is strongly associated with many dental and oral mucosal diseases, and may contribute to others. Our study of a relatively small sample of 200 patients, of whom 33 percent were tobacco users, found statistically significant data correlating tobacco use with a higher Decayed, Missing and Filled Index (a measurement of caries and tooth loss experience of patients) and relating periodontal bone loss to smokeless tobacco use. And, while this investigation did not find a statistically significant correlation between smoking and periodontitis severity, there was a data trend in that direction. Conclusions about tooth loss in the Indiana monograph were limited to smokers; however, there was an association of ST use with gingival recession, which can become quite severe in the area in which the smokeless tobacco is placed. It might be theorized that the significantly larger number of missing teeth among ST users in our study is associated with the generally poor oral hygiene and less sophisticated outlook on health care that tobacco users often display. Indeed, of the 65 denture wearers in our study, 7.7 percent were ST users and 40.0 percent were tobacco users of some type. In view of the large amount of data in the scientific literature associating tobacco with dental diseases as summarized by the Indiana monograph, and the position of several groups such as the American Cancer Society that tobacco is one of the risk factors most associated with intraoral cancer, it would appear that dentists have a vested professional interest in promoting tobacco use cessation among their patients. Dentists should take every reasonable opportunity to persuade patients to discontinue the tobacco habit, thus preventing life

  11. Productivity in dental care for children. Factors influencing the time spent delivering dental care.

    PubMed

    Wang, N J

    1994-12-01

    The cost of dental services is related to their productivity. The purpose of the study was to identify factors influencing productivity, measured as time spent providing dental care per child under care, per year, in public dental clinics. The time was expected to vary with characteristics of the patients, the personnel and the clinics. Time spent by dentists and dental hygienists delivering dental care for children aged three to 18 years was obtained from 137 public dental clinics. The data showed substantial variation in productivity between clinics. Multiple regression analysis revealed that the time spent per child was associated with interval between examinations, proportion of male dentists, ratio of dental assistants to dentists, proportion of child treatment time given by dental hygienists and proportion of all treatment time spent on child patients. These variables explained 43 per cent of the variance in the total time spent by dentists and hygienists and 41 per cent of the variance in dentists' time. Individual dentists and hygienists may reduce the mean time spent per child by extending recall intervals. On an administrative level, dentists' time per child may be reduced by employing more dental assistants or dental hygienists and allowing dentists to treat patient groups other than children. It is concluded that productivity in dental care for children in the public dental services may be influenced in several ways, both by clinical and administrative decisions. PMID:7850642

  12. Issues in Dental Hygiene Education and Practice: Perceptions and Concerns of Dental Hygiene Program Administrators.

    ERIC Educational Resources Information Center

    League for Innovation in the Community Coll., Los Angeles, CA.

    A survey was conducted by the League for Innovation in the Community College and Johnson County Community College to determine the state of the dental hygiene profession. The study sought the opinions of all dental hygiene program administrators in the United States and Canada regarding the principal concerns facing dental hygiene education and…

  13. Dental and allied dental students' attitudes towards and perceptions of intraprofessional education.

    PubMed

    Brame, Jennifer L; Mitchell, Shannon H; Wilder, Rebecca S; Sams, Lattice D

    2015-06-01

    Interprofessional and intraprofessional learning opportunities in health professions education are vital to emphasize evidence-based practice, quality improvement, and cost-effectiveness in patients' oral health care. The aim of this study was to assess dental, dental hygiene, and dental assisting students' readiness for intraprofessional education and to evaluate their attitudes towards and perceptions of intraprofessional teamwork, communication, respect, and understanding of professional roles. In 2013, students at one dental school (N=247) were surveyed, and focus groups were conducted for this convergent parallel mixed-methods study. Survey response rates were as follows: senior dental students 54.4% (N=43), senior dental hygiene students 100% (N=32), dental assisting students 95% (N=19), junior dental students 51.8% (N=42), and junior dental hygiene students 100% (N=33). The results showed that the dental hygiene students had more positive responses about intraprofessional education than the dental and dental assisting students (p<0.05). Most (94%, N=160) of the respondents in the combined groups agreed that intraprofessional learning would help them become more effective members of the oral health care team. The three focus group sessions (N=17) revealed consistency among the groups regarding the value of an integrated clinical design and intraprofessional education. These students were eager and positive about intraprofessional learning and agreed that a shared learning model can improve communication and respect among team members, provide a better understanding of roles, and ultimately enhance patient care. PMID:26034025

  14. Posttraumatic dental-care anxiety (PTDA): Is "dental phobia" a misnomer?

    PubMed

    Bracha, H Stefan; Vega, Edward M; Vega, Carrie B

    2006-01-01

    In this brief review article, we suggest that the term "dental phobia" may be a misnomer. The problem with using the term "phobia" in a dental-care context is as follows: by definition, phobias involve a fear that is "excessive or unreasonable," which the individual recognizes as such, and in which the anxiety, panic attacks and phobic avoidance are not better accounted for by another disorder, including posttraumatic stress disorder (PTSD). In our experience, most individuals with dental "phobia" do not recognize their symptoms as "excessive or unreasonable" and in that sense, resemble individuals with PTSD. Our review of the dental-care literature suggests that true (innate) dental phobias (akin to unreasonable fear at the sight of blood or a syringe) probably account for a smaller percentage of cases, and that the vast majority of dental-care anxiety (DA) cases stem from aversive dental experiences. Research has documented that individuals who reported having experienced painful dental treatments and perceived a lack of control in the dental situation were approximately 14 times more likely to also report higher dental fear, and approximately 16 times more likely to report being less willing to return to the dental treatment. Therefore, we propose that this psychological condition should be conceptualized as Posttraumatic Dental-Care Anxiety (PTDA), and should be classified as part of the Posttraumatic Stress Disorder (PTSD) spectrum in the forthcoming Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-V). PMID:17152624

  15. Microfractures in metal-ceramic and all-ceramic implant-supported fixed dental prostheses caused by superstructure fixation.

    PubMed

    Karl, Matthias; Graef, Friedrich; Wichmann, Manfred; Beck, Nina

    2012-01-01

    The effect of ceramic veneering on the passivity of fit of cast metal and CAD/CAM-fabricated zirconia ceramic implant-supported three-unit cement-retained restorations was investigated, as well as the effect of misfit stress on the marginal integrity of ceramic veneers. Superstructures were fabricated using cast metal or by CAD/CAM milling of presintered or HIP zirconia ceramic (n=10). Before and after veneering, strain gages were used to measure in vitro the strain developed in all the restorations as a result of superstructure fixation. Fluorescent penetrant method was used to detect microcracks developed in ceramic veneers. Cast frameworks showed significantly higher strain values than CAD/CAM frameworks (p=0.000). Veneering significantly increased strain development in all CAD/CAM frameworks (p=0.000). Compared to zirconia ceramic restorations, significantly more microcracks were observed in cast restorations (p=0.000) both before and after superstructure fixation. PMID:22673463

  16. Nanostructured Surfaces of Dental Implants

    PubMed Central

    Bressan, Eriberto; Sbricoli, Luca; Guazzo, Riccardo; Tocco, Ilaria; Roman, Marco; Vindigni, Vincenzo; Stellini, Edoardo; Gardin, Chiara; Ferroni, Letizia; Sivolella, Stefano; Zavan, Barbara

    2013-01-01

    The structural and functional fusion of the surface of the dental implant with the surrounding bone (osseointegration) is crucial for the short and long term outcome of the device. In recent years, the enhancement of bone formation at the bone-implant interface has been achieved through the modulation of osteoblasts adhesion and spreading, induced by structural modifications of the implant surface, particularly at the nanoscale level. In this context, traditional chemical and physical processes find new applications to achieve the best dental implant technology. This review provides an overview of the most common manufacture techniques and the related cells-surface interactions and modulation. A Medline and a hand search were conducted to identify studies concerning nanostructuration of implant surface and their related biological interaction. In this paper, we stressed the importance of the modifications on dental implant surfaces at the nanometric level. Nowadays, there is still little evidence of the long-term benefits of nanofeatures, as the promising results achieved in vitro and in animals have still to be confirmed in humans. However, the increasing interest in nanotechnology is undoubted and more research is going to be published in the coming years. PMID:23344062

  17. Dental amalgam--environmental aspects

    SciTech Connect

    Arenholt-Bindslev, D. )

    1992-09-01

    Increasing knowledge about the risk of toxic effects caused by anthropogenic mercury accumulation in ecosystems has resulted in a growing pressure for reduction of the discharge of mercury waste. Consequently, the mercury waste problems of dental clinics have been given increased attention, and restrictions on handling and discharge of contaminated waste have been established in several countries. Major amalgam particles from trituration surplus of those produced during the carving and burnishing of new amalgam restorations are generally collected in coarse filters and sold for refinement. Minor amalgam particles released by production of new fillings or by removal of old restorations partly sediment in tubes and drains. The remaining particles are carried with the waste water stream to the local purifying plant. In Scandinavia, the industrial discharge of mercury-contaminated waste water has been reduced to a minimum. According to recent investigations, dental clinics appear to be responsible for the major amount of mercury collected in the sludge generated in purifying plants. If threshold values for heavy metal content, including mercury, are exceeded, the sludge is not allowed to be recycled as fertilizer. Installation of an approved amalgam-separating apparatus in dental clinics is now mandatory in several countries--for example, Switzerland, Germany, Sweden, and Denmark. Approval of amalgam separators is based on national testing programs, including clinical or laboratory tests demanding 95-99% separating efficiency. 18 refs.

  18. Navy Dental Corps: ninety years ... and forward.

    PubMed

    Woofter, Dennis D; Peters, Andrew; Kvaska, Greg; Turner, Carol I; Peters, Robert J; Shaffer, Richard G; Sobocinski, Andre B

    2003-01-01

    The Navy Dental Corps is responsible for ensuring the readiness of America's sailors and marines and optimizing their oral health. This article traces the history from the 1912 Act of Congress authorizing thirty "assistant dental surgeons" as the first Navy Dental Corps through service around the world. Navy dentists have seen service in every war and action in the past ninety years, reaching a peak of seven thousand officers and eleven thousand technicians in World War II. The Navy Dental Corps has served in the Korean and Vietnam Wars, Beirut, Somalia, Haiti, 9/11, Desert Storm, Desert Shield, and Operation Iraqi Freedom. PMID:12892336

  19. Functional expression of dental plaque microbiota.

    PubMed

    Peterson, Scott N; Meissner, Tobias; Su, Andrew I; Snesrud, Erik; Ong, Ana C; Schork, Nicholas J; Bretz, Walter A

    2014-01-01

    Dental caries remains a significant public health problem and is considered pandemic worldwide. The prediction of dental caries based on profiling of microbial species involved in disease and equally important, the identification of species conferring dental health has proven more difficult than anticipated due to high interpersonal and geographical variability of dental plaque microbiota. We have used RNA-Seq to perform global gene expression analysis of dental plaque microbiota derived from 19 twin pairs that were either concordant (caries-active or caries-free) or discordant for dental caries. The transcription profiling allowed us to define a functional core microbiota consisting of nearly 60 species. Similarities in gene expression patterns allowed a preliminary assessment of the relative contribution of human genetics, environmental factors and caries phenotype on the microbiota's transcriptome. Correlation analysis of transcription allowed the identification of numerous functional networks, suggesting that inter-personal environmental variables may co-select for groups of genera and species. Analysis of functional role categories allowed the identification of dominant functions expressed by dental plaque biofilm communities, that highlight the biochemical priorities of dental plaque microbes to metabolize diverse sugars and cope with the acid and oxidative stress resulting from sugar fermentation. The wealth of data generated by deep sequencing of expressed transcripts enables a greatly expanded perspective concerning the functional expression of dental plaque microbiota. PMID:25177549

  20. Interfacial toughness of bilayer dental ceramics based on a short-bar, chevron-notch test

    PubMed Central

    Anunmana, Chuchai; Anusavice, Kenneth J.; Mecholsky, John J.

    2009-01-01

    Objective The objective of this study was to test the null hypothesis that the interfacial toughness of each of two types of bonded core-veneer bilayer ceramics is not significantly different from the apparent fracture toughness of the control monolithic glass veneer. Methods T-shaped short bars of a lithia-disilicate glass-ceramic core (LC) and yttria-stabilized polycrystalline zirconia core ceramic (ZC) were prepared according to the manufacturer's recommendations. V-shaped notches were prepared by using 25-μm-thick palladium foil, leaving the chevron notch area exposed, and the bars were veneered with a thermally compatible glass veneer (LC/GV and ZC/GV). Additionally, we also bonded the glass veneer to itself as a control group (GV/GV). Specimens were kept in distilled water for 30 days before testing in tension. Eight glass veneer bars were prepared for the analysis of fracture toughness test using the indentation-strength technique. Results The mean interfacial toughness of the LC/GV group was 0.69 [0.11] MPa·m1/2, and did not significantly differ from that of the GV/GV control group, 0.74 (0.17) MPa·m1/2 (p > 0.05). However, the difference between the mean interfacial toughness of the ZC/GV group, 0.13 (0.07) MPa·m1/2, and the LC/GV and the GV/GV groups was statistically significant (p<0.05). Significance For bilayer all-ceramic restorations with high-strength core materials, the veneering ceramics are the weakest link in the design of the structure. Since all-ceramic restorations often fail from chipping of veneer layers or crack initiation at the interface, the protective effects of thermal mismatch stresses oral prosthesis design should be investigated. PMID:19818486

  1. Attitudes and beliefs toward the use of a dental diagnostic terminology A survey of dental providers in a dental practice

    PubMed Central

    Ramoni, Rachel B.; Walji, Muhammad F.; Kim, Soyun; Tokede, Oluwabunmi; McClellan, Lyle; Simmons, Kristen; Skourtes, Eugene; Yansane, Alfa; White, Joel M.; Kalenderian, Elsbeth

    2015-01-01

    Background Attitudes and views are critical to the adoption of innovation. While there have been broadening calls for a standardized dental diagnostic terminology, little is known about the views of private practice dental team members towards the adoption of such a terminology. Methods A survey was developed using validated questions identified through literature review. Domain experts’ input allowed for further modifications. The final survey was administered electronically to 814 team members at a multi-office practice based in the Pacific Northwest. Results Response proportion was 92%. The survey had excellent reliability (Cronbach alpha coefficient = 0.87). Results suggested that participants showed, in general, positive attitudes and beliefs towards using a standardized diagnostic terminology in their practices. Additional written comments by participants highlighted the potential for improved communication with use of the terminology. Conclusions Dental providers and staff in one multi-office practice showed positive attitudes towards the use of a diagnostic terminology, specifically they believed it would improve communication between the dentist and patient as well as among providers, while expressing some concerns if using standardized dental diagnostic terms helps clinicians to deliver better dental care. Practical Implications As the dental profession is advancing towards the use of standardized diagnostic terminologies, successful implementation will require that dental team leaders prepare their dental teams by gauging their attitude toward the use of such a terminology. PMID:26025826

  2. The relationship between dental anxiety and dental decay experience in antenatal mothers.

    PubMed

    Esa, Rashidah; Savithri, Vengadasalam; Humphris, Gerry; Freeman, Ruth

    2010-02-01

    The aim of this study was to investigate the relationship between dental anxiety and dental decay experience among antenatal mothers attending Maternal and Child Health clinics in Malaysia. A cross-sectional study was conducted on a consecutive sample of 407 antenatal mothers in Seremban, Malaysia. The questionnaire consisted of participants' demographic profile and the Dental Fear Survey. The D(3cv)MFS was employed as the outcome measure and was assessed by a single examiner (intraclass correlation = 0.98). A structural equation model was designed to inspect the relationship between dental anxiety and dental decay experience. The mean Dental Fear Survey score for all participants was 35.1 [95% confidence interval (34.0, 36.3)]. The mean D(3cv)MFS score was 10.8 [95% confidence interval (9.5, 12.1)]. Participants from low socio-economic status groups had significantly higher D(3cv)MFS counts than those from high socio-economic status groups. The path model with dental anxiety and socio-economic status as predictors of D(3cv)MFS showed satisfactory fit. The correlation between dental anxiety and dental decay experience was 0.30 (standardized estimate), indicating a positive association. Socio-economic status was also statistically significantly associated with the D(3cv)MFS count (beta = 0.19). This study presented robust evidence for the significant relationship between dental anxiety and dental decay experience in antenatal mothers. PMID:20156266

  3. Eliminating Medicaid adult dental coverage in California led to increased dental emergency visits and associated costs.

    PubMed

    Singhal, Astha; Caplan, Daniel J; Jones, Michael P; Momany, Elizabeth T; Kuthy, Raymond A; Buresh, Christopher T; Isman, Robert; Damiano, Peter C

    2015-05-01

    Dental coverage for adults is an elective benefit under Medicaid. As a result of budget constraints, California Medicaid eliminated its comprehensive adult dental coverage in July 2009. We examined the impact of this policy change on emergency department (ED) visits by Medicaid-enrolled adults for dental problems in the period 2006-11. We found that the policy change led to a significant and immediate increase in dental ED use, amounting to more than 1,800 additional dental ED visits per year. Young adults, members of racial/ethnic minority groups, and urban residents were disproportionately affected by the policy change. Average yearly costs associated with dental ED visits increased by 68 percent. The California experience provides evidence that eliminating Medicaid adult dental benefits shifts dental care to costly EDs that do not provide definitive dental care. The population affected by the Medicaid adult dental coverage policy is increasing as many states expand their Medicaid programs under the ACA. Hence, such evidence is critical to inform decisions regarding adult dental coverage for existing Medicaid enrollees and expansion populations. PMID:25941275

  4. Changes in dental fluorosis and dental caries in Newburgh and Kingston, New York.

    PubMed Central

    Kumar, J V; Swango, P A; Lininger, L L; Leske, G S; Green, E L; Haley, V B

    1998-01-01

    OBJECTIVES: This study sought to determine whether the prevalence of dental fluorosis and dental caries had changed in a fluoridated community and a nonfluoridated community since an earlier study conducted in 1986. METHODS: Dental fluorosis and dental caries data were collected on 7- to 14-year-old lifelong residents (n = 1493) of Newburgh and Kingston, NY. RESULTS: Estimated dental fluorosis prevalence rates were 19.6% in Newburgh and 11.7% in Kingston. The greatest disparity in caries scores was observed between poor and nonpoor children in nonfluoridated Kingston. CONCLUSIONS: The prevalence of dental fluorosis has not declined in Newburgh and Kingston, whereas the prevalence of dental caries has continued to decline. PMID:9842391

  5. [Dental hygiene indices for dental practice (methods and experiences)].

    PubMed

    Hiltbold, B

    1976-10-01

    An oral hygiene recording sheet for clinical practices with a dental hygienist is described. The recording sheets allow an easy and clear survey of the present oral hygiene status as well as progress or negligence in the performance of oral hygiene procedures. Several oral hygiene indices are described, three of which are recommended for routine examinations: The plaque index of Silness/Löe, the sulcus bleeding index of Mühlemann/Son and the calculus surface index of Ennever et al. The experience of a 3-year use of the oral hygiene recording sheets is described. PMID:1070805

  6. [Applications of lasers in dental implantology].

    PubMed

    Mu, Yue; Li, Qian; Zhao, Ji-zhi

    2014-10-01

    With the constant progress of laser physics, medical laser technology has been widely applied in clinical practices and basic researches. In this article, we reviewed the relevant articles on the laser applications in dental implantology and concluded that lasers provides promising solutions in the treatment technology of dental implants and in the treatment of soft and hard tissue conditions. PMID:25360659

  7. Stress Management Training for Dental Students.

    ERIC Educational Resources Information Center

    Tisdelle, Debra A.; And Others

    1984-01-01

    A group of dental students participated in a stress management program that included instruction in self-relaxation and time management, exercise and leisure planning, and cognitive modification techniques. The importance of stress-management training for dental students and suggestions for future research are discussed. (MLW)

  8. Survey Practices in Dental Education Research.

    ERIC Educational Resources Information Center

    Creswell, John W.; Kuster, Curtis G.

    1983-01-01

    The use of mailed questionnaires in research on dental education is examined, and several factors that researchers should consider when reporting mailed questionnaire research to journal editors are identified. Examples from the "Journal of Dental Education" are used. (Author/MLW)

  9. The Chemistry of Modern Dental Filling Materials.

    ERIC Educational Resources Information Center

    Nicholson, John W.; Anstice, H. Mary

    1999-01-01

    Discusses materials used by dentists to restore teeth after decay has been removed. Shows how dental-material science is an interdisciplinary field in which chemistry plays a major part. Reviews the many developments polymer chemistry has contributed to the field of dental fillings. (CCM)

  10. Ethical sourcing of dental instruments and materials.

    PubMed

    Kelly, P T; Bhutta, M

    2010-10-23

    There is evidence that dental instruments and materials are being manufactured in the developing world under poor labour conditions. It is suggested that the level of awareness of the dental team with regard to this is raised and that a culture of greater inquiry into the sourcing of instruments and materials is developed. PMID:20966996

  11. Health Instruction Packages: Consumer--Dental Hygiene.

    ERIC Educational Resources Information Center

    Tanner, Floyd R.; And Others

    Text, illustrations, and exercises are utilized in this set of five learning modules to instruct dental patients and the general public in the fundamental principles of dental hygiene. The first module, "Identify the Responsibilities for Your Oral Health" by Floyd R. Tanner, discusses the respective roles of the dentist and the patient in…

  12. First Aid Procedures for Dental Emergencies.

    ERIC Educational Resources Information Center

    Barsky, Nancy Happel; Londeree, Kathy

    1982-01-01

    Guidelines for first aid procedures for temporary relief of dental emergencies include information on: (1) dental first aid supplies; (2) treatment of oral injuries; (3) orthodontic emergencies; (4) toothaches; and (5) prolonged bleeding due to an extraction. Consulting a dentist as soon as possible is strongly recommended. (JN)

  13. 38 CFR 51.170 - Dental services.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Dental services. 51.170 Section 51.170 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) PER DIEM FOR NURSING HOME CARE OF VETERANS IN STATE HOMES Standards § 51.170 Dental services. (a) A...

  14. 38 CFR 51.170 - Dental services.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2012-07-01 2012-07-01 false Dental services. 51.170 Section 51.170 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) PER DIEM FOR NURSING HOME CARE OF VETERANS IN STATE HOMES Standards § 51.170 Dental services. (a) A...

  15. 38 CFR 51.170 - Dental services.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2013-07-01 2013-07-01 false Dental services. 51.170 Section 51.170 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) PER DIEM FOR NURSING HOME CARE OF VETERANS IN STATE HOMES Standards § 51.170 Dental services. (a) A...

  16. 38 CFR 51.170 - Dental services.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2011-07-01 2011-07-01 false Dental services. 51.170 Section 51.170 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) PER DIEM FOR NURSING HOME CARE OF VETERANS IN STATE HOMES Standards § 51.170 Dental services. (a) A...

  17. 38 CFR 51.170 - Dental services.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2014-07-01 2014-07-01 false Dental services. 51.170 Section 51.170 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) PER DIEM FOR NURSING HOME CARE OF VETERANS IN STATE HOMES Standards § 51.170 Dental services. (a) A...

  18. Equity in dental care among Canadian households

    PubMed Central

    2011-01-01

    Background Changes in third party financing, whether public or private, are linked to a household's ability to access dental care. By removing costs at point of purchase, changes in financing influence the need to reach into one's pocket, thus facilitating or limiting access. This study asks: How have historical changes in dental care financing influenced household out-of-pocket expenditures for dental care in Canada? Methods This is a mixed methods study, comprised of an historical review of Canada's dental care market and an econometric analysis of household out-of-pocket expenditures for dental care. Results We demonstrate that changes in financing have important implications for out-of-pocket expenditures: with more financing come drops in the amount a household has to spend, and with less financing come increases. Low- and middle-income households appear to be most sensitive to changes in financing. Conclusions Alleviating the price barrier to care is a fundamental part of improving equity in dental care in Canada. How people have historically spent money on dental care highlights important gaps in Canadian dental care policy. PMID:21496297

  19. Adults with Disabilities and Proper Dental Care

    ERIC Educational Resources Information Center

    Waldman, H. Barry; Perlman, Steven P.; Cinotti, Debra A.

    2009-01-01

    Repeated studies of graduating dental students indicate limited preparation to provide services for individuals with special healthcare needs. By the end of the 1990s and into the present decade, more than half of the U.S. dental schools provided less than five hours of class room presentations and about three quarters of the schools provided 0-5…

  20. Dental Student Stress, Burnout, and Memory.

    ERIC Educational Resources Information Center

    Davis, Elaine L.; And Others

    1989-01-01

    A study examined the relationships between self-reported academic burnout, perceived dental educational stress, and memory performance among 46 first-year dental students. In addition, the observed relationship between negative adjectives used for self-description and memory focused attention on the possible role of mood state in memory…