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Sample records for provisional restoration materials

  1. Provisional material considerations: creating a blueprint of the final restorations.

    PubMed

    Helvey, Gregg A

    2014-01-01

    Indirect restorative dentistry generally requires temporization of prepared teeth during the laboratory fabrication phase. Over the years, the physical properties of newer provisional materials have improved, which has enabled an expansion of the function of provisional restorations. Better strength, surface finish, and color match have increased their acceptability by patients and clinicians. In some clinical situations provisional restorations can provide information that is critical to the overall success of a case. Such information allows the clinician to verify and confirm with the patient the esthetics, phonetics, and function of the proposed anterior restorative treatment. The provisional restorations can also provide valuable information to the laboratory technician regarding design, contour, length, shade, and even correct articulation of the master model. The success of the definitive restoration is dependent on the accurate transfer of this information to the laboratory technician.

  2. Long-term reinforced fixed provisional restorations.

    PubMed

    Galindo, D; Soltys, J L; Graser, G N

    1998-06-01

    Extensive prosthodontic treatment often requires fabrication of long-term provisional restorations. Numerous materials and techniques have been described for prolonged insertion of interim restorations. This article describes a procedure for fabrication of long-term reinforced heat-processed provisional restorations based on a diagnostic wax-up. Reinforced heat-processed provisional restorations reduced flexure, which minimizes progressive loss of cement and diminished the possibility of recurrent decay. Occlusal stability and vertical dimension were maintained because of greater wear resistance. Occlusion, tooth contours, and pontic design developed in the provisional restoration were duplicated in the definitive restoration. The use of a matrix from a diagnostic wax-up facilitated fabrication of the prosthesis, and made the procedure less time-consuming and more predictable.

  3. Long-term esthetic provisional restorations in dentistry.

    PubMed

    Lodding, D W

    1997-01-01

    The role of interim dental restorations used for indirect restorative and prosthodontic procedures has changed dramatically in the past several years. These restorations are no longer regarded as temporary restorations but rather as provisional restorations with distinct functions and purposes. Provisional restorations have become a vital diagnostic and assessment tool to evaluate function color, shape, contour, occlusion, periodontal response, implant healing, and overall esthetics. An accurate fit and margination is essential to insure and maintain pulpal health of the tooth. With increased demands being placed on provisional restorations, new materials and techniques are being developed and some existing protocols are being refined to accomplish the desired goals. Provisional restorations are often in the oral environment for several months, requiring a well-fabricated and stable restoration. This review is designed to report on current materials, techniques, and concepts in fabricating and maintaining long-term esthetic provisionals.

  4. Fixed provisional restorations for extended prosthodontic treatment.

    PubMed

    Amet, E M; Phinney, T L

    1995-01-01

    During extensive and extended prosthodontic treatment, there is need for a durable esthetic fixed provisional restoration that can be easily modified as treatment is completed and that is cost-effective. The needed strength of provisional restorations can be underestimated, and the management of complex treatment is then more difficult and the prosthetic results less predictable. Knowledge of the criteria for treatment restorations and the adequacies of their construction is essential for the prevention of catastrophic failures, patient management problems, and compromised results. Many times in complex prosthodontic treatment, changes are needed in esthetics, the plane of occlusion, incisal edge position, lip support, and type of occlusion, or the soft and/or hard tissues need to be altered or grafted surgically. In addition, after first- and second-stage implant surgery and extractions, there is a need for immediate tooth replacement with extended time between prosthodontic treatments. These prosthodontic changes and challenges can be addressed with reinforced acrylic provisional restorations that are adequately cemented and retained during the interim stage of healing and treatment. In addition, the provisional restoration should serve as a guide for the final restoration while esthetics and phonetics are evaluated for patient acceptance. This article describes the materials used with an indirect technique for fabrication of an extended-treatment acrylic provisional restoration that uses an internal cast metal support system for strength. This support system consists of metal bands or copings with extensions into edentulous areas and that have been opaqued to neutralize the metallic color. A matrix of vinyl polysiloxane made from the diagnostic wax-up simplifies construction of the acrylic, resulting in a strong, ridged, yet esthetic result.

  5. Provisionalization for ceramic laminate veneer restorations: a clinical update.

    PubMed

    Nixon, R L

    1997-01-01

    At the inception of ceramic veneer restorations in the early 1980s, provisional veneer restorations were not customarily placed over teeth which had undergone tooth reduction. During the last several years, provisional veneer restorations have been utilized with increased frequency for a variety of valid reasons. The learning objective of this article is to examine the reasons for the increased utilization of provisional veneer restorations and to describe a selection of the clinical methods employed for direct and indirect fabrication. The indications and contraindications for provisionalization are presented. Four case reports are utilized to describe and illustrate the various clinical circumstances, the provisionalization procedures, the appropriate instruments, and the materials that facilitate the fabrication of aesthetic, functionally sound, and biocompatible provisional restorations.

  6. Role of provisional restorations in endodontic therapy

    PubMed Central

    Sivakumar, Jambai Sampathkumar; Suresh Kumar, Beri Narasimiah; Shyamala, Palaniyandi Vadivel

    2013-01-01

    Root-canal treatment can be carried out in single visit in vital, non-infected teeth, eliminating the need for dressing and provisionalization. Many clinical cases with infected canals require dressing with antibacterial medicaments in a multivisit treatment in which effective provisionalization for different periods of time becomes mandatory. Successful root-canal treatment requires effective mechanical and chemical debridement, elimination of bacteria and pulp tissue remnants and proper canal shaping to facilitate effective obturation. Lack of satisfactory temporary restorations during endodontic therapy ranked second amongst the contributing factors in continuing pain after the commencement of treatment. This review aims to provide an overview of the materials used for provisionalization during and immediately after endodontic treatment. PMID:23946564

  7. Integrating fixed and removable provisional restorations.

    PubMed

    Curtis, S R

    1993-10-01

    When both fixed and removable components are required, provisional restorations can be difficult. This article describes a technique where provisional restoration "shells" are made with a plastic stent of the diagnostic wax-up on lightly prepared teeth of a diagnostic cast. An acrylic removable partial denture is then waxed to the shells. The shells are relined intraorally after tooth preparation with the partial denture in place.

  8. Direct technique for the fabrication of a visible light-curing resin provisional restoration.

    PubMed

    Passon, C; Goldfogel, M

    1990-09-01

    A properly fabricated provisional restoration will, among other things, provide acceptable esthetics. Although many materials have been used for provisional restorations, when esthetics is of primary concern, the choice is limited to tooth-colored resin materials. Recently, a tooth-colored, light-activated urethane dimethacrylate resin has been developed. This material has been reported to be useful for many prosthetic applications, including the indirect fabrication of provisional restorations. This paper presents a technique for the direct fabrication of single-unit provisional restorations using this material. The physical properties of this resin and the advantages and disadvantages of the technique are also discussed.

  9. Techniques of fabrication of provisional restoration: an overview.

    PubMed

    Regish, K M; Sharma, Deeksha; Prithviraj, D R

    2011-01-01

    A properly fabricated provisional restoration is important in achieving a successful indirect restoration. The importance of provisional restorations as an integral part of fixed prosthodontic treatment is evident from the abundance of the literature pertaining to their importance regarding margin fidelity, function, occlusion, and esthetics. There are a variety of techniques available to suit the individual needs of the clinician and of the clinical situation, from a single unit to a complete-arch provisional fixed prostheses.

  10. Techniques of Fabrication of Provisional Restoration: An Overview

    PubMed Central

    Regish, K. M.; Sharma, Deeksha; Prithviraj, D. R.

    2011-01-01

    A properly fabricated provisional restoration is important in achieving a successful indirect restoration. The importance of provisional restorations as an integral part of fixed prosthodontic treatment is evident from the abundance of the literature pertaining to their importance regarding margin fidelity, function, occlusion, and esthetics. There are a variety of techniques available to suit the individual needs of the clinician and of the clinical situation, from a single unit to a complete-arch provisional fixed prostheses. PMID:22013441

  11. Evaluation of surface finish and polish of eight provisional restorative materials using acrylic bur and abrasive disk with and without pumice.

    PubMed

    Maalhagh-Fard, Ahmad; Wagner, Warren C; Pink, Frank E; Neme, Ann Marie

    2003-01-01

    This study evaluated the effects of two finishing techniques and pumice polishing on the surface roughness of eight different provisional materials. Provisional materials included polymethylmethacrylate-based Alike, Snap, Trim and Jetand composite-based provisional materials Temphase, Protemp 3 Garant, Luxatemp and Integrity. Baseline surface roughness was measured by a profilometer, then the provisional materials were finished using extra fine acrylic burs or medium abrasive disks. The surface roughness of each sample was measured following finishing using a profilometer as previously stated. Each surface was then polished with pumice and the surface roughness was measured again. The data were analyzed using repeated measures of ANOVA and Bonferroni pairwise comparisons (alpha = 0.05). The results indicated that with composite provisional materials, the unfinished surfaces are smoother than with bur or abrasive-disk finished surfaces. Pumice application did not smooth the surface finish for all materials. The different types of provisional materials required different finishing techniques to produce the smoothest finishes.

  12. In vitro color stability of provisional restorations.

    PubMed

    Yaman, P; Razzoog, M; Brandau, H E

    1989-04-01

    A provisional restoration must protect the prepared tooth, provide comfort and function and be esthetically acceptable and color stable. This study measured the degree of color change of provisional restorations. Five commercially available resins were evaluated: Trim, Tab, Kind, Snap and Duralay. Five cylindrical samples of each resin were fabricated by mixing the powder and the liquid to a predetermined ratio and pouring the mix into a mold. The Minolta Chroma Meter II Reflectance was used to establish the baseline color L* a* b*. The resins were then subjected to accelerated in vitro aging in a Weather-O-Meter and color readings were recorded. The color differentials on delta E* were computed for each sample (delta E*ab = [(delta L*)2+(delta b*)2]1/2). The difference is a quantitative measurement of color change. The National Bureau of Standards describes delta E* as units (NBS Unit = delta E*ab x 0.92). With this parameter only the allowable delta E*ab need be specified rather than the range of allowable L*, a*, b* values. This is important for color comparison and quality control functions. The results showed that Kind had a slight color change delta E* = -1.72, Trim demonstrated the most color change delta E* = -13.84, while the remaining resins demonstrated a noticeable change in color due to in vitro aging.

  13. The science of communicating the art of esthetic dentistry. Part II: Diagnostic provisional restorations.

    PubMed

    Derbabian, K; Marzola, R; Donovan, T E; Cho, G C; Arcidiacono, A

    2000-01-01

    Provisional restorations fulfill many functions in restorative dentistry. Quality provisional restorations can provide the clinician, the patient, and the laboratory technician much valuable information prior to fabrication of the definitive restoration. Such diagnostic provisional restorations fabricated with acrylic resin are easily adjusted and modified until both esthetic and functional results are approved by the patient. Once this approval has been obtained, the definitive restorations can be fabricated with confidence, using the esthetic form of the provisional restorations as a blueprint.

  14. A comparison of wire- and Kevlar-reinforced provisional restorations.

    PubMed

    Powell, D B; Nicholls, J I; Yuodelis, R A; Strygler, H

    1994-01-01

    Stainless steel wire 0.036 inch in diameter was compared with Kevlar 49 polyaramid fiber as a means of reinforcing a four-unit posterior provisional fixed restoration with 2 pontics. Three reinforcement patterns for wire and two for Kevlar 49 were evaluated and compared with the control, which was an unreinforced provisional restoration. A central tensile load was placed on the cemented provisional restoration and the variables were measured: (1) the initial stiffness; (2) the load at initial fracture; and (3) the unit toughness, or the energy stored in the beam at a point where the load had undergone a 1.0-mm deflection. Statistical analysis showed (1) the bent wire configuration had a significantly higher initial stiffness (P < or = .05), (2) there was no difference between designs for load at initial fracture, and (3) the bent wire had a significantly higher unit toughness value (P < or = .05).

  15. Comparison of temperature rise in pulp chamber during polymerization of materials used for direct fabrication of provisional restorations: An in-vitro study

    PubMed Central

    Khajuria, Rajat R.; Madan, Ravi; Agarwal, Swatantra; Gupta, Reecha; Vadavadgi, Sunil V.; Sharma, Vikas

    2015-01-01

    Objective: The purpose is to compare temperature rise in the pulp chamber during fabrication of provisional crowns using different materials and on different types of teeth using direct technique. Materials and Methods: An extracted, sound, caries free maxillary central incisor and a mandibular molar were selected for the study and crown preparations of all ceramic and all metal were done on central incisor and mandibular molar, respectively. Materials tested were DPI tooth molding self-curing material and protemp-4. Addition silicone putty was used as a matrix and 80 provisional crowns were fabricated, of which 40 were on central incisor and 40 on mandibular molar. Depending on the type of material used, they were further divided into two subgroups: Each comprising 20 provisional crowns. Temperature readings were recorded using K type of thermocouple with 0.1°C precision digital thermometer. Statistical Analysis Used: Analysis of variance, Tukey honest significant difference and Kruskall–Wallis H-test. Results: Statistically significant difference exists between two materials tested on the basis of peak temperature achieved and time taken by a particular material to reach peak temperature. Peak temperature achieved was highest for provisional crowns with DPI tooth molding self-curing material on maxillary central incisor (40.39 + 0.46), followed by DPI tooth molding self-curing material on mandibular molar (40.03 + 0.32), protemp-4 on maxillary central incisor (39.46 + 0.26) and least with protemp-4 on mandibular molar (39.09 + 0.33). The time taken to reach peak temperature was almost double in DPI tooth molding self-curing material (5 min) than in protemp-4. Conclusion: Polymethyl methacrylate resin produced higher intra-pulpal rise when compared to newer generation bis-acrylic composite. PMID:26038649

  16. Aesthetic provisional restoration for the partially edentulous, immediate, postimplantation patient.

    PubMed

    McCord, J F; Smith, G A; Quayle, A A

    1992-01-01

    This article reviews the methods currently used for making provisional restorations for endosseous dental implants. With the requirements for osseointegration in mind, a simple and aesthetic alternative is suggested. The clinical and laboratory stages for the fabrication of the prosthesis are outlined.

  17. Mechanical properties of four methylmethacrylate-based resins for provisional fixed restorations.

    PubMed

    Hernandez, E P; Oshida, Y; Platt, J A; Andres, C J; Barco, M T; Brown, D T

    2004-01-01

    The use of a provisional restoration is an important phase in the treatment of the dental prosthetic patient. A good provisional restoration should satisfy the following requirements: pulpal protection, positional stability, ease in cleaning, accurate margins, wear resistance, dimensional stability, and serve as a diagnostic aid in treatment assessment and esthetics. There is a tendency for discoloration, occlusal wear, and fracture that eventually leads to unnecessary repair. Heat-processed and reinforced methacrylate-based resins have been used to improve the mechanical and physical properties of provisional restorations. Among various improvements, the interpenetrating network crosslinked PMMA (IPN) has been shown to have superior mechanical properties if manufactured through a dough compression molding process at 130 degrees C. However, there have been no published data that relate with the use of this material for fixed provisional restorations. The objective of this study was to compare four methyl methacrylate-based resins for provisional crowns and bridges with varying processing cycles, including JET [self-cure], ACRALON [heat-cured], titanium dioxide filled PMMA [heat-cured], and IPN [heat-cured denture tooth resin]. Properties studied included transverse strength, toughness, rigidity, and hardness. From the results of this study the following conclusions can be made: the IPN group may have had a lower degree of conversion as demonstrated by decreased strength, toughness, and hardness data as compared with Acralon. Increasing the polymerization cycle of unmodified Acralon resin causes a significant increase in strength.

  18. A technique for indirect fabrication of an implant-supported, screw-retained, fixed provisional restoration in the esthetic zone.

    PubMed

    Lin, Wei-Shao; Ercoli, Carlo

    2009-12-01

    This article describes an alternative technique for the fabrication of an implant-supported, screw-retained, fixed provisional restoration in the esthetic zone. After an implant-level impression is made with a polyether impression material, the provisional restoration is fabricated indirectly. This technique is easy, saves time, and has economic advantages, while maintaining color stability and esthetic properties for the provisional restoration. It may be contraindicated for severely misaligned implants that require extensive reduction of the implant temporary abutments and denture teeth laminates.

  19. Fabrication of a fixed provisional restoration utilizing a light-curing acrylic resin.

    PubMed

    Trushkowsky, R D

    1992-06-01

    The properly fabricated provisional restoration must take into account the following interrelated factors: pulpal protection, periodontal health, occlusion, esthetics, and phonetics. The techniques advocated for construction of a provisional restoration include direct, indirect, and a combination of direct and indirect techniques. Two simple techniques that use light-curing acrylic resin for the fabrication of fixed provisional restorations are presented, and advantages and disadvantages of these techniques are discussed.

  20. Production of a Fixed Provisional Restoration Using an Acrylic Denture: Technique and Case Report.

    PubMed

    Kocaagaoglu, Hasan

    2015-07-01

    The damage or loss of anterior teeth causes a negative impact on the patient in many ways. In adolescents and young patients, the provisional replacement with artificial teeth may minimize this impact. Many approaches have been described for provisional restorations. This article discusses about a chairside fixed provisional restoration technique that was adjusted into the edentulous area of a 15-year-old girl. PMID:26393221

  1. Production of a Fixed Provisional Restoration Using an Acrylic Denture: Technique and Case Report

    PubMed Central

    2015-01-01

    The damage or loss of anterior teeth causes a negative impact on the patient in many ways. In adolescents and young patients, the provisional replacement with artificial teeth may minimize this impact. Many approaches have been described for provisional restorations. This article discusses about a chairside fixed provisional restoration technique that was adjusted into the edentulous area of a 15-year-old girl. PMID:26393221

  2. Trends in indirect dentistry: 6. Provisional restorations, more than just a temporary.

    PubMed

    Burke, F J Trevor; Murray, Madeleine C; Shortall, Adrian C C

    2005-10-01

    The provision of well-fitting, functional provisional restorations is important for a wide variety of reasons, including maintenance of the stability of inter- and intra-arch relationships and positional stability of prepared teeth, and the preservation of occlusal function of anterior provisional restorations by providing appropriate protrusive and lateral guidance. Provisional restorations should be of sufficient strength to resist the forces of occlusion and should be luted with a cement that will resist the forces of removal, yet allow easy removal at the fit appointment without leaving a residue on the prepared tooth. This paper describes the use of provisional restorations in indirect restorative dentistry and suggests some specific techniques for clinical use.

  3. Effect of light-curing, pressure, oxygen inhibition, and heat on shear bond strength between bis-acryl provisional restoration and bis-acryl repair materials

    PubMed Central

    Shim, Ji-Suk; Lee, Jeong-Yol; Choi, Yeon-Jo; Shin, Sang-Wan

    2015-01-01

    PURPOSE This study aimed to discover a way to increase the bond strength between bis-acryl resins, using a comparison of the shear bond strengths attained from bis-acryl resins treated with light curing, pressure, oxygen inhibition, and heat. MATERIALS AND METHODS Self-cured bis-acryl resin was used as both a base material and as a repair material. Seventy specimens were distributed into seven groups according to treatment methods: pressure - stored in a pressure cooker at 0.2 Mpa; oxygen inhibition- applied an oxygen inhibitor around the repaired material,; heat treatment - performed heat treatment in a dry oven at 60℃, 100℃, or 140℃. The shear bond strength was measured with a universal testing machine, and the shear bond strength (MPa) was calculated from the peak load of failure. A comparison of the bond strength between the repaired specimens was conducted using one-way ANOVA and Tukey multiple comparison tests (α=.05). RESULTS There were no statistically significant differences in the shear bond strength between the control group and the light curing, pressure, and oxygen inhibition groups. However, the heat treatment groups showed statistically higher bond strengths than the groups treated without heat, and the groups treated at a higher temperature resulted in higher bond strengths. Statistically significant differences were seen between groups after different degrees of heat treatment, except in groups heated at 100℃ and 140℃. CONCLUSION Strong bonding can be achieved between a bis-acryl base and bis-acryl repair material after heat treatment. PMID:25722837

  4. Comparative Evaluation of Flexural Strength of Provisional Crown and Bridge Materials-An Invitro Study

    PubMed Central

    Garg, Sandeep

    2016-01-01

    Introduction Provisional restorations serve a key role as a functional and esthetic try-in for the design of the final prosthesis. During selection of materials for this restoration, clinicians must consider physical properties, ease of handling, cost and patient satisfaction and approval. Aim To evaluate and compare the flexural strength of provisional crown and bridge materials available commercially. Materials and Methods This in-vitro study was done to compare the flexural strength of six temporary crown and bridge materials available commercially at 24 hours, 8 days and after repair. Three poly methyl methacrylate based materials (DPI, SC10 and Trulon) and three bis-acrylic based composite resins (Protemp, Cooltemp and Luxatemp) were selected. A total of 72 specimens of dimensions 64mm×10mm×2.5mm were prepared from these materials (12 from each material) and divided into two groups (n=36). Specimens were stored in artificial saliva and were fractured after 24 hours and 8 days using Universal Testing Machine. The fractured samples from the 8 days study were then subjected to repair. A uniform space of 2mm and a 450 bevel was maintained for all the repaired samples for better distribution of forces. Flexural strength of these repaired samples was recorded using the same machine. Results were recorded and statistically analysed by one-way Anova and Post hoc tests. Result: Results revealed that there was decrease in flexural strength for all the materials tested from 24 hours to 8 days, though flexural strength between poly methyl methacrylate and bis-acrylic resins was similar at 24 hours and 8 days time interval. A substantial decrease was noticed in the strength of bis-acrylic composite resins after repair. Conclusion From the current study it can be suggested that though there is decrease in flexural strength for all the materials from 24 hours to 8 days, both can be used to fabricate the provisional restorations. However, in the event of a fracture of a bis

  5. Wire-reinforced, light-cured glass ionomer-resin provisional restoration: a description of the technical procedure.

    PubMed

    Liebenberg, W H

    1994-09-01

    A procedure to use round-wire and glass ionomer-resin cement to make practical provisional restorations is presented. The viability of the use of glass ionomer-resin cement and the need for embrasure perfection in provisional restorations is discussed. This procedure is suitable as a long-term provisional restoration where extensive coronal destruction has occurred. The inherent disadvantage of the procedure is the need to involve occlusal surfaces of the proximal teeth; thus its use is restricted to mouths in which the adjacent teeth are to receive simultaneous restorative treatment.

  6. In vitro study of fracture strength of provisional crown materials

    PubMed Central

    Sayin, Gulsum; Kara, Ozlem

    2015-01-01

    PURPOSE The purpose of this report was to evaluate the effect of the fabrication method and material type on the fracture strength of provisional crowns. MATERIALS AND METHODS A master model with one crown (maxillary left second premolar) was manufactured from Cr-Co alloy. The master model was scanned, and the data set was transferred to a CAD/CAM unit (Yenamak D50, Yenadent Ltd, Istanbul, Turkey) for the Cercon Base group. For the other groups, temporary crowns were produced by direct fabrication methods (Imident, Temdent, Structur Premium, Takilon, Systemp c&b II, and Acrytemp). The specimens were subjected to water storage at 37℃ for 24 hours, and then they were thermocycled (TC, 5000×, 5-55℃) (n=10). The maximum force at fracture (Fmax) was measured in a universal test machine at 1 mm/min. Data was analyzed by non-parametric statistics (α=.05). RESULTS Fmax values varied between 711.09-1392.1 N. In the PMMA groups, Takilon showed the lowest values (711.09 N), and Cercon Base showed the highest values (959.59 N). In the composite groups, Structur Premium showed the highest values (1392.1 N), and Acrytemp showed the lowest values (910.05 N). The composite groups showed significantly higher values than the PMMA groups (P=.01). CONCLUSION Composite-based materials showed significantly higher fracture strengths than PMMA-based materials. The CAD-CAM technique offers more advantages than the direct technique. PMID:25722834

  7. The effect of glass and polyethylene fiber reinforcement on flexural strength of provisional restorative resins: an in vitro study.

    PubMed

    Natarajan, Parthasarathy; Thulasingam, C

    2013-12-01

    The aim is to evaluate and compare the flexural strength of different provisional restorative materials reinforced with glass and polyethylene fibers. A total of 90 samples were prepared and divided into three groups based on the type of fiber reinforcement, unidirectional S-glass (Splint-It) and ultra-molecular weight polyethylene (Ribbond). Unreinforced samples served as control group. Again each group was subdivided into three subgroups based on type of provisional restorative resins, heats cure polymethyl methacrylate, self-cure poly methyl methacrylate and self-cure bis-acryl composite. Samples were loaded in a universal testing machine until fracture occurs. The mean flexural strengths (MPa) were subjected to the one-way ANOVA, followed by the Tukey-HSD test at a significance level of 0.001. The result shows all the fiber reinforced samples possessed greater strength than the control samples. In control samples, the heat cure poly methyl methacrylate resin (72.74 ± 2.28 MPa) had the greatest flexural strength, followed by self-cure bis-acryl composite (67.05 ± 2.35 MPa) and self-cure poly methyl methacrylate resin (52.88 ± 1.90 MPa). In both heat and self-cure poly methyl methacrylate resin, the polyethylene fiber reinforcement (96.00 ± 2.63 MPa, 86.17 ± 1.92 MPa) provides the greatest strength than glass fiber reinforcement (92.68 ± 1.58 MPa, 76.40 ± 2.11 MPa). In self-cure bis-acryl composite, the glass fiber (105.95 ± 3.07 MPa) shows better reinforcement than polyethylene fiber (99.41 ± 1.74 MPa).The fibers reinforcement increases the flexural strength of provisional restorative resins.

  8. Design of a cast bar reinforced provisional restoration for the management of the interim phase in implant dentistry.

    PubMed

    Saba, S

    1999-03-01

    Implant therapy is becoming the treatment of choice for the replacement of teeth in partially edentulous arches. The interim phase of implant treatment often presents particular problems because of the position of the remaining teeth, their periodontal status, and the loss of vertical dimension of occlusion. This case report will discuss the design and fabrication of a cast bar reinforced long-span provisional restoration based on a diagnostic wax-up to simplify the management of the interim phase.

  9. In vitro comparison of flexural strength and elastic modulus of three provisional crown materials used in fixed prosthodontics

    PubMed Central

    Poonacha, Seema; Salagundi, Basavaraj; Rupesh, P L.; Raghavan, Rohit

    2013-01-01

    Objectives: To evaluate and compare the flexural strength and the elastic moduli of three provisional crown materials (methyl methacrylate based autopolymerized resin, bis acryl composite based autopolymerized resin and urethane dimethacrylate based light polymerized resin) after storing in artificial saliva and testing at intervals of 24 hours and 7 days. Study design: A metal master mould with four slots of dimensions 25x2x2 mm was fabricated to obtain samples of standard dimensions. A total of 135 specimens were thus obtained with 45 each of three provisional materials. Further 15 samples of each group were tested after storing for one hour at room temperature and again at intervals of 24 hours and 7 days after storing in artificial saliva. Three point flexural tests were carried out in the universal testing machine to calculate the flexural strength and the elastic modulus. The changes were calculated and data was analyzed with Fisher’s test and ANOVA. Results: The flexural strength of the methyl methacrylate resin reduced significantly while bis-acrylic composite resin showed a significant increase in its flexural strength after storing in artificial saliva for 24 hours and the values of both remained constant thereafter. Contrary to these findings, light polymerized resin showed a significant decrease in flexural strength after storing in artificial saliva for 24 hours and then significantly increased in flexural strength after 7 days. However the changes in the values for elastic modulus of respective materials were statistically insignificant. Conclusion: Methacrylate based autopolymerizing resin showed the highest flexural strength and elastic moduli after fabrication and after storing in artificial saliva and for 24 hours and 7 days. Bis-acrylic composite resin showed the least flexural strength and elastic moduli. Key words:Provisional restorations, interim restorations, Methyl Methacrylate, composite restoration, flexural strength, elastic moduli

  10. Comparative Evaluation of Marginal Discrepancy in Tooth Colored Self Cure Acrylic Provisional Restorations With and Without Reinforcement of Glass Beads: An In-Vitro Study

    PubMed Central

    Yasangi, Manoj Kumar; Mannem, Dhanalakshmi; Neturi, Sirisha; Ravoori, Srinivas; Jyothi

    2015-01-01

    Context This invitro study was conducted to compare and evaluate marginal discrepancy in two types of tooth colored self cure provisional restorative materials {DPI&UNIFAST TRAD} before and after reinforcement of glass beads. Aim The aim of the present study was to evaluate and compare marginal discrepancy in two types of provisional restorative materials (DPI and UNI FAST TRAD) before and after reinforcement with Glass beads. Materials and Methods Tooth shaped resin copings were fabricated on custom made brass metal die. A total of 60 resin copings were fabricated in which 30 samples were prepared with DPI and 30 samples with UNIFAST material. Each group of 30 samples were divided in to two sub groups in which 15 samples were prepared with glass bead reinforcement and 15 samples without reinforcement. The marginal discrepancy was evaluated with photomicroscope {Reichet Polyvar 2 met} by placing the resin copings on custom made brass resin coping holder. Results Measurements obtained were statistically analysed by unpaired t-test to know any significance between two variables. Unreinforced DPI specimens had shown lower marginal discrepancy (442.82) than reinforced specimens (585.77). Unreinforced UNIFAST specimens have shown high values of marginal discrepancy (592.83) than reinforced specimens (436.35). p-value between reinforced and unreinforced specimens of DPI (p=0.0013) and UNIFAST (p= 0.0038) has shown statistical significance. Conclusion This in-vitro study revealed that unreinforced DPI specimens have shown lower marginal discrepancy than reinforced specimens and unreinforced UNIFAST specimens have shown higher values of marginal discrepancy than reinforced specimens. PMID:26155574

  11. In Vitro Fit and Cementation Resistance of Provisional Crowns for Single Implant-Supported Restorations.

    PubMed

    Moris, Izabela Cristina Maurício; Oliveira, Juliana Elias de; Faria, Adriana Cláudia Lapria; Ribeiro, Ricardo Faria; Rodrigues, Renata Cristina Silveira

    2015-10-01

    This study aimed to verify marginal fit and the effect of cement film thickness standardization on retention of provisional crowns made with prefabricated acrylic cylinders on abutments, using two temporary luting agents subjected or not to mechanical cycling. Provisional crowns were made from bis-acryl (Luxatemp Fluorescence) or methyl methacrylate (Duralay) resins on acrylic cylinders and marginal fit and cement film thickness were evaluated. For retention evaluation, crowns were cemented with two temporary luting agents: non-eugenol zinc oxide (Tempbond NE) or calcium hydroxide-based (Hydcal) cements and subjected to tensile strength in a universal testing machine. After cleaning, debonded crowns were cemented again, subjected to mechanical cycling and retention was reassessed. The results of marginal fit and cement film thickness were analyzed by Student's t-test while retention of cements before and after mechanical cycling was analyzed using a mixed linear model. Methyl methacrylate crowns presented greater marginal misfit (p=0.001) and occlusal cement film thickness (p=0.003) than the bis-acryl ones. No difference was observed at axial cement film thickness (p=0.606). Resins (p=0.281) did not affect crown retention, but luting agents (p=0.029) and mechanical cycling (p=0.027) showed significant effects. The only significant interaction was mechanical cycling*luting agents, which means that luting agents were differently affected by mechanical cycling (p=0.002). In conclusion, the results showed that bis-acryl resin associated to calcium-hydroxide luting agent provided the best retention and lower cement thickness.

  12. Provisional anterior tooth replacement using nonimpregnated fiber and fiber-reinforced composite resin materials: a clinical report.

    PubMed

    Chan, Daniel C N; Giannini, Marcelo; De Goes, Mario Fernando

    2006-05-01

    The loss of anterior teeth is often a serious esthetic concern. While conventional fixed partial dentures and implant-supported restorations may be the treatments of choice, nonimpregnated fibers (NFs) and fiber-reinforced composite (FRC) resins offer a conservative alternative for improving esthetics. This article describes 2 clinical situations in which NF glass ribbon and FRC were successfully used to provisionally restore anterior edentulous areas in an esthetic, functional, and timely manner. PMID:16679128

  13. Provisional anterior tooth replacement using nonimpregnated fiber and fiber-reinforced composite resin materials: a clinical report.

    PubMed

    Chan, Daniel C N; Giannini, Marcelo; De Goes, Mario Fernando

    2006-05-01

    The loss of anterior teeth is often a serious esthetic concern. While conventional fixed partial dentures and implant-supported restorations may be the treatments of choice, nonimpregnated fibers (NFs) and fiber-reinforced composite (FRC) resins offer a conservative alternative for improving esthetics. This article describes 2 clinical situations in which NF glass ribbon and FRC were successfully used to provisionally restore anterior edentulous areas in an esthetic, functional, and timely manner.

  14. Evaluation of the effect of various beverages and food material on the color stability of provisional materials – An in vitro study

    PubMed Central

    Gupta, Gaurav; Gupta, Tina

    2011-01-01

    Aim: This study evaluated the color stability of four provisional materials: 1) Poly-methyl methacrylates (DPI); 2) Bis-acryl composite (ProtempTM II – 3M ESPE); 3) Bis-acryl composite (Systemp® c and b – Ivoclar Vivadent) and 4) Light polymerized composite resin (Revotek LC- GC). Materials and Methods: The color and color difference of each specimen after immersion in different staining solutions i.e. 1) tea and artificial saliva, 2) coffee and artificial saliva, 3) Pepsi and artificial saliva, 4) turmeric solution and artificial saliva was measured using reflectance spectrophotometer with CIELAB system before immersion and after immersion at 2, 5 ,7 , 10 and 15 days. Results: Revotek LC- GC (light polymerized composite resin) was found to be the most color stable provisional restorative material followed by Protemp II (Bis-acryl composite), Systemp (Bis-acryl composite) and DPI (Methylmethacrylate resin). Turmeric solution had the maximum staining potential followed by coffee, tea and Pepsi. PMID:22025835

  15. Evaluation of Light-Activated Provisional Resin Materials for Periodontal Soft Tissue Management

    PubMed Central

    Jun, Soo-Kyung; Lee, Hae-Hyoung

    2016-01-01

    The purpose of this study was to determine mechanical properties using a compressive test with cylinder specimen (h = 6 mm and ϕ = 4 mm) as well as cytotoxicity using elutes from disk specimen (ϕ = 10 mm and h = 2 mm) against human gingival fibroblasts and oral keratinocytes with light-activated provisional resin materials (Revotek LC and Luxatemp Solar) compared to chemically activated counterpart (Snap, Trim II, and Jet). Significantly increased compressive strength (210~280 MPa) was detected in light-activated products compared to chemically activated ones (20~65 MPa, P < 0.05) and similar compressive modulus was detected in both types (0.8~1.5 and 0.5~1.3 GPa). Simultaneously, the light-activated products showed less adverse effects on the periodontal soft tissue cells in any polymerization stage compared to the chemically activated products. Particularly, chemically activated products had significantly greater adverse effects during the “polymerizing” phase compared to those that were “already set” (P < 0.05), as shown in confocal microscopic images of live and dead cells. In conclusion, light-activated provisional resin materials have better mechanical properties as well as biocompatibility against two tested types of oral cells compared to the chemically activated counterpart, which are considered as more beneficial choice for periodontal soft tissue management. PMID:27672651

  16. Evaluation of Light-Activated Provisional Resin Materials for Periodontal Soft Tissue Management

    PubMed Central

    Jun, Soo-Kyung; Lee, Hae-Hyoung

    2016-01-01

    The purpose of this study was to determine mechanical properties using a compressive test with cylinder specimen (h = 6 mm and ϕ = 4 mm) as well as cytotoxicity using elutes from disk specimen (ϕ = 10 mm and h = 2 mm) against human gingival fibroblasts and oral keratinocytes with light-activated provisional resin materials (Revotek LC and Luxatemp Solar) compared to chemically activated counterpart (Snap, Trim II, and Jet). Significantly increased compressive strength (210~280 MPa) was detected in light-activated products compared to chemically activated ones (20~65 MPa, P < 0.05) and similar compressive modulus was detected in both types (0.8~1.5 and 0.5~1.3 GPa). Simultaneously, the light-activated products showed less adverse effects on the periodontal soft tissue cells in any polymerization stage compared to the chemically activated products. Particularly, chemically activated products had significantly greater adverse effects during the “polymerizing” phase compared to those that were “already set” (P < 0.05), as shown in confocal microscopic images of live and dead cells. In conclusion, light-activated provisional resin materials have better mechanical properties as well as biocompatibility against two tested types of oral cells compared to the chemically activated counterpart, which are considered as more beneficial choice for periodontal soft tissue management.

  17. Fracture resistance of posterior teeth restored with modern restorative materials

    PubMed Central

    Hamouda, Ibrahim M.; Shehata, Salah H.

    2011-01-01

    We studied the fracture resistance of maxillary premolars restored with recent restorative materials. Fifty maxillary premolars were divided into five groups: Group 1 were unprepared teeth; Group 2 were teeth prepared without restoration; Group 3 were teeth restored with tetric ceram HB; Group 4 were teeth restored with InTen S; and Group 5 were teeth restored with Admira. The samples were tested using a universal testing machine. Peak loads at fracture were recorded. The teeth restored with Admira had the highest fracture resistance followed by those restored with InTen-S and tetric ceram HB. Prepared, unrestored teeth were the weakest group. There was a significant difference between the fracture resistance of intact teeth and the prepared, unrestored teeth. There was also a significant difference among the tested restorative materials. Teeth restored with Admira showed no significant difference when compared with the unprepared teeth. It was concluded that the teeth restored with Admira exhibited the highest fracture resistance. PMID:23554719

  18. Full-arch metal-resin cement- and screw-retained provisional restoration for immediately loaded implants.

    PubMed

    Baig, Mirza Rustum; Rajan, Gunaseelan

    2010-01-01

    Abstract This article describes the clinical and laboratory procedures involved in the fabrication of laboratory-processed, provisional, screw-retained, implant-supported maxillary and mandibular fixed complete dentures incorporating a cast metal reinforcement for immediate loading of implants. Precise fit is achieved by intraoral luting of the cast frame to milled abutments. Effective splinting of all implants is attained by the metal substructure and retrievability is provided by the screw-retention of the prosthesis. PMID:20553176

  19. Provisional License.

    ERIC Educational Resources Information Center

    Preusser, David F.; Leaf, William A.

    2003-01-01

    Describes the phase in a graduated driver-licensing system that includes the provisional license, which allows young people to drive under certain restrictions. Discusses how the licensing system has emerged as an important factor in reducing crash rates among teenage drivers. (Contains 1 table, 2 figures, and 18 references.) (WFA)

  20. An Investigation Into the Integrity of Fit of Provisional Crowns Using Current Proprietary Temporary Crown Materials.

    PubMed

    Taylor, Philip D; Georgakis, Georgios; Niggli, Jason

    2016-06-01

    Three methods of direct provisional crown construction were investigated for accuracy of marginal fit. A modified proprietary crown coping was compared to Bis GMA and isobutyl methacrylate resin provisional crowns with margins modified by using a flowable composite and 'bead on' isobutyl methacrylate respectively. Measurement was at 50x magnification at seven sites over the fit surface. Data was analyzed using SPSS version 13.0.1 and measurement compared using the Mann Whitney test set at a significance level of 0.05. Reliability was checked using the Bland Altman test. Statistical significant differences were found between the three groups. The order of best fit was Bis-GMA and flowable composite > isobutyl methacrylate with 'bead on' margins > Bis-GMA modified implant temporary coping. The clinical significance is that the Bis GMA and flowable composite combination can be used with equal confidence to traditional methods of temporarisation. PMID:27424335

  1. Smile design and advanced provisional fabrication.

    PubMed

    Malone, Mike

    2008-05-01

    Cosmetic reconstruction is much more predictable when superb provisionals are used as a blueprint for the final restoration. This article provides details for a technique that can be used to fabricate indirect multilayered composite provisional restorations for porcelain veneers and complex full-arch cases.

  2. A comparative evaluation of the marginal accuracy of crowns fabricated from four commercially available provisional materials: An in vitro study

    PubMed Central

    Amin, Bhavya Mohandas; Aras, Meena Ajay; Chitre, Vidya

    2015-01-01

    Purpose: The purpose of this in vitro study was to evaluate and compare the primary marginal accuracy of four commercially available provisional materials (Protemp 4, Luxatemp Star, Visalys Temp and DPI tooth moulding powder and liquid) at 2 time intervals (10 and 30 min). Materials and Methods: A customized stainless steel master model containing two interchangeable dies was used for fabrication of provisional crowns. Forty crowns (n = 10) were fabricated, and each crown was evaluated under a stereomicroscope. Vertical marginal discrepancies were noted and compared at 10 min since the start of mixing and then at 30 min. Observations and Results: Protemp 4 showed the least vertical marginal discrepancy (71.59 μ), followed by Luxatemp Star (91.93 μ) at 10 min. DPI showed a marginal discrepancy of 95.94 μ while Visalys Temp crowns had vertical marginal discrepancy of 106.81 μ. There was a significant difference in the marginal discrepancy values of Protemp 4 and Visalys Temp. At 30 min, there was a significant difference between the marginal discrepancy of Protemp 4 crowns (83.11 μ) and Visalys Temp crowns (128.97 μ) and between Protemp 4 and DPI (118.88 μ). No significant differences were observed between Protemp 4 and Luxatemp Star. Conclusion: The vertical marginal discrepancy of temporary crowns fabricated from the four commercially available provisional materials ranged from 71 to 106 μ immediately after fabrication (at 10 min from the start of mix) to 83–128 μ (30 min from the start of mix). The time elapsed after mixing had a significant influence on the marginal accuracy of the crowns. PMID:26097348

  3. Direct restoration of worn maxillary anterior teeth with a combination of composite resin materials: a case report.

    PubMed

    Soares, Carlos José; Pizi, Eliane Cristina Gava; Fonseca, Rodrigo Borges; Martins, Luis Roberto Marcondes; Neto, Alfredo Júlio Fernandes

    2005-01-01

    Tooth loss, alterations on tooth structure, and reduced vertical dimension are known to severely compromise the stomatognathic system. This case report describes the treatment of a patient who presented with an extremely worn maxillary anterior dentition with a loss of posterior support owing to the loss of almost all the posterior teeth, except the mandibular premolars. Provisional removable partial dentures were used to create an optimum maxillomandibular relationship and to provide restorative space prior to the restoration of the remaining teeth. This restoration was accomplished with a combination of layered hybrid and microfilled composite materials, which restored the maxillary anterior teeth to optimum esthetics and function.

  4. [Restoration materials in overdenture abutment teeth].

    PubMed

    Keltjens, H M; Creugers, T J; van 't Hof, M A; Creugers, N H

    2000-08-01

    To assess the performance of amalgam, resin composite and resin-modified glass ionomer cement as filling material in overdenture abutment teeth, 155 restorations were made to seal the root canal orifices in 49 patients. The three restorative materials were randomly assigned to the abutment teeth using a number of balancing criteria. All patients were reviewed every six months and received the same preventive regimen. Survival was assessed at two levels: complete survival even without maintenance treatments (Scomp) and survival of the original restoration independent from eventual maintenance treatments (Sorig). The calculated overall survival of Sorig and Scomp were 63 +/- 6% and 57 +/- 6% respectively (mean +/- SE). At both levels no statistically significant differences were observed between the survival of the investigated materials. The results of this study did not point out a superior restorative material for the seal of root canal orifices of overdenture abutment teeth. The distribution of failures over the patients indicated a certain patient dependency.

  5. A Single Visit Direct Technique to Provisionally Restore Occlusion for a Full-Mouth Rehabilitation: A Clinical Report.

    PubMed

    El-Kerdani, Tarek; Nimmo, Arthur

    2016-01-01

    Attrition of the dentition can negatively affect esthetics and function. When reconstructing patients with attrition who require restoration at increased occlusal vertical dimension (OVD), it is necessary to first evaluate the OVD using a removable interim prosthesis to ensure that the patient will tolerate the new position. The transition to fixed interim prostheses has to be carefully planned to achieve the desired OVD. One approach is to prepare all teeth in a single day and place full-arch interim prostheses; however, this can be tiring for the patient and prosthodontist. An alternative approach is to prepare one arch and place interim prostheses, while using composite resin in the opposing arch to maintain the newly established OVD. A diagnostic wax-up at the proposed OVD is completed and duplicated in stone. A vacuform matrix is loaded with composite resin and applied to the unprepared etched teeth of the opposing arch to restore form and occlusion until full contour interim prostheses are placed at a later visit.

  6. RADIOPACITY OF RESTORATIVE MATERIALS USING DIGITAL IMAGES

    PubMed Central

    Salzedas, Leda Maria Pescinini; Louzada, Mário Jefferson Quirino; de Oliveira, Antonio Braz

    2006-01-01

    The radiopacity of esthetic restorative materials has been established as an important requirement, improving the radiographic diagnosis. The aim of this study was to evaluate the radiopacity of six restorative materials using a direct digital image system, comparing them to the dental tissues (enamel-dentin), expressed as equivalent thickness of aluminum (millimeters of aluminum). Five specimens of each material were made. Three 2-mm thick longitudinal sections were cut from an intact extracted permanent molar tooth (including enamel and dentin). An aluminum step wedge with 9 steps was used. The samples of different materials were placed on a phosphor plate together with a tooth section, aluminum step wedge and metal code letter, and were exposed using a dental x-ray unit. Five measurements of radiographic density were obtained from each image of each item assessed (restorative material, enamel, dentin, each step of the aluminum step wedge) and the mean of these values was calculated. Radiopacity values were subsequently calculated as equivalents of aluminum thickness. Analysis of variance (ANOVA) indicated significant differences in radiopacity values among the materials (P<0.0001). The radiopacity values of the restorative materials evaluated were, in decreasing order: TPH, F2000, Synergy, Prisma Flow, Degufill, Luxat. Only Luxat had significantly lower radiopacity values than dentin. One material (Degufill) had similar radiopacity values to enamel and four (TPH, F2000, Synergy and Prisma Flow) had significantly higher radiopacity values than enamel. In conclusion, to assess the adequacy of posterior composite restorations it is important that the restorative material to be used has enough radiopacity, in order to be easily distinguished from the tooth structure in the radiographic image. Knowledge on the radiopacity of different materials helps professionals to select the most suitable material, along with other properties such as biocompatibility, adhesion and

  7. What constitutes an ideal dental restorative material?

    PubMed

    Rekow, E D; Bayne, S C; Carvalho, R M; Steele, J G

    2013-11-01

    Intense environmental concerns recently have prompted dentistry to evaluate the performance and environmental impact of existing restoration materials. Doing so entices us to explore the 'what if?' innovation in materials science to create more ideal restorative materials. Articulating a specification for our design and evaluation methods is proving to be more complicated than originally anticipated. Challenges exist not only in specifying how the material should be manipulated and perform clinically but also in understanding and incorporating implications of the skill of the operator placing the restoration, economic considerations, expectations patients have for their investment, cost-effectiveness, influences of the health care system on how and for whom restorations are to be placed, and global challenges that limit the types of materials available in different areas of the world. The quandary is to find ways to actively engage multiple stakeholders to agree on priorities and future actions to focus future directions on the creation of more ideal restorative materials that can be available throughout the world.

  8. [Dental restoration materials in pediatric dentistry].

    PubMed

    Davidson, C L

    1997-02-01

    Restorative materials in pediatric dentistry have to fulfill special requirements. They should be easy to handle and applicable in a not always dry mouth. They should potentially be adhesive in order to avoid too much mechanical preparation. They do not have to be extremely wear resistant as the dwell time of the restorations is relatively short. Glass-ionomer cements and in particular the resin modified types possess properties which make them almost ideal for the required purpose.

  9. [Key points in anterior esthetic restorations with all ceramic].

    PubMed

    Luo, Xiaoping; Qian, Dongdong; Yuan, Yu; Meng, Xiangfeng

    2013-04-01

    This paper introduced the key points in fabricating anterior esthetic restorations with all ceramic materials, including pre-operative smile design, standard tooth preparation, provisional restoration fabrication, all ceramic materials selection, all ceramic restoration bonding, ceramic crack and fracture prevention. And then, the authors summarized and reviewed the clinical common problems in anterior esthetic restorations. PMID:23662547

  10. [Key points in anterior esthetic restorations with all ceramic].

    PubMed

    Luo, Xiaoping; Qian, Dongdong; Yuan, Yu; Meng, Xiangfeng

    2013-04-01

    This paper introduced the key points in fabricating anterior esthetic restorations with all ceramic materials, including pre-operative smile design, standard tooth preparation, provisional restoration fabrication, all ceramic materials selection, all ceramic restoration bonding, ceramic crack and fracture prevention. And then, the authors summarized and reviewed the clinical common problems in anterior esthetic restorations.

  11. Color stability evaluation of aesthetic restorative materials.

    PubMed

    Samra, Adriana Postiglione Bührer; Pereira, Stella Kossatz; Delgado, Leyla Cotrina; Borges, Christiane Phillipini

    2008-01-01

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

  12. [Clinical problems of microleakage of restorative materials in primary teeth].

    PubMed

    Gonzalez Marquez, M I; Gonzalez Rodriguez, E; Menendez Nunez, M

    1990-10-01

    The purpose of this research is to evaluate the clinical problems associated with microleakage of different restorative materials. We have compared the microleakage when we restore Class II cavities in primary molars with amalgams and with posterior composite resins. The results of this study suggest that posterior composite resins present more frequently pulp inflammation, necrosis, marginal discoloration and secondary marginal caries. This factors mus to be considered when we choose a material for temporary restoration.

  13. Material and clinical considerations for full-coverage indirect restorations.

    PubMed

    Martin, Margaret P

    2012-11-01

    Because dental ceramics have been used for decades and continuously improved over the years, there is a plethora of information regarding their material characteristics, applications, and contraindications. Each restorative ceramic material demonstrates benefits and disadvantages, making it difficult for dentists to research, retain, and apply the ideal material for individual restorations and/or combination cases. This article outlines the applications and benefits of dental ceramics in general and examines and reviews the current ceramic alternatives available for restorative dentistry today. It also discusses the material composition and properties of a recently introduced new classification of indirect material: resin nano-ceramic.

  14. Various Effects of Sandblasting of Dental Restorative Materials

    PubMed Central

    Nishigawa, Goro; Maruo, Yukinori; Irie, Masao; Maeda, Naoto; Yoshihara, Kumiko; Nagaoka, Noriyuki; Matsumoto, Takuya; Minagi, Shogo

    2016-01-01

    Background Sandblasting particles which remain on the surfaces of dental restorations are removed prior to cementation. It is probable that adhesive strength between luting material and sandblasting particle remnants might exceed that with restorative material. If that being the case, blasting particles adhere to sandblasted material surface could be instrumental to increasing adhesive strength like underlying bonding mechanism between luting material and silanized particles of tribochemical silica coating-treated surface. We hypothesize that ultrasonic cleaning of bonding surfaces, which were pretreated with sandblasting, may affect adhesive strength of a resin luting material to dental restorative materials. Methods We therefore observed adhesive strength of resin luting material to aluminum oxide was greater than those to zirconia ceramic and cobalt-chromium alloy beforehand. To measure the shear bond strengths of resin luting material to zirconia ceramic and cobalt-chromium alloy, forty specimens of each restorative material were prepared. Bonding surfaces were polished with silicon abrasive paper and then treated with sandblasting. For each restorative material, 40 sandblasted specimens were equally divided into two groups: ultrasonic cleaning (USC) group and non-ultrasonic cleaning (NUSC) group. After resin luting material was polymerized on bonding surface, shear test was performed to evaluate effect of ultrasonic cleaning of bonding surfaces pretreated with sandblasting on bond strength. Results For both zirconia ceramic and cobalt-chromium alloy, NUSC group showed significantly higher shear bond strength than USC group. Conclusions Ultrasonic cleaning of dental restorations after sandblasting should be avoided to retain improved bonding between these materials. PMID:26764913

  15. Chairside CAD/CAM: an overview of restorative material options.

    PubMed

    Fasbinder, Dennis J

    2012-01-01

    A number of categories of materials are available for chairside CAD/CAM restorations that have demonstrated predictability and longevity. These materials include esthetic and high-strength ceramics, composite resins for both final and temporary restorations, and newer nanoceramics that offer ease of handling and a glossy surface finish. Each category of materials has unique features designed for specific clinical applications. This article will examine currently available materials designed for chairside CAD/CAM restorations and the various outcomes that are possible with this technologically advanced process.

  16. Development of Native Plant Materials for Use in Restoration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The development of native plant materials for restoration demands that close attention be paid to the expectations of the specialized customer base of restoration practitioners. Native and introduced plants are not biologically different, but they are usually very different in how they are marketed...

  17. Lithium disilicate: the restorative material of multiple options.

    PubMed

    Culp, Lee; McLaren, Edward A

    2010-01-01

    As dentistry continues to evolve, new technologies and materials are continually being offered to the dental profession. Throughout the years restorative trends and techniques have come and gone. Some material developments have transformed the face of esthetic dentistry, while other initial concepts have already phased out and disappeared. Today, all-ceramic restorations continue to grow in the area of restorative dentistry, from pressed-ceramic techniques and materials to the growing use of zirconia, and new materials that can be created from CAD/CAM technology. This article will explore new uses for the all-ceramic material known as lithium disilicate, and the use of a digital format to design and process this material in new and exciting ways. An overview of the material as well as unique clinical procedures will be presented.

  18. Direct and indirect adhesive restorative materials: a review.

    PubMed

    Kugel, G

    2000-11-01

    Esthetic restorative materials require a bonding procedure in order to be durable and reliable. In order to accomplish this ideal, the bonding system must be biocompatible, bond indifferently to enamel and dentin, have sufficient strength to resist masticator forces, have mechanical properties close to those of tooth structures, be resistant to degradation in the oral environment and easy to use. This paper reviews the published literature on direct and indirect adhesive restorative materials.

  19. Nanotechnology-based restorative materials for dental caries management

    PubMed Central

    Melo, Mary A.S.; Guedes, Sarah F.F.; Xu, Hockin H.K.; Rodrigues, Lidiany K.A.

    2013-01-01

    Nanotechnology has been applied to dental materials as an innovative concept for the development of materials with better properties and anticaries potential. In this review we discuss the current progress and future applications of functional nanoparticles incorporated in dental restorative materials as useful strategies to dental caries management. We also overview proposed antimicrobial and remineralizing mechanisms. Nanomaterials have great potential to decrease biofilm accumulation, inhibit the demineralization process, to be used for remineralizing tooth structure, and to combat caries-related bacteria. These results are encouraging and open the doors to future clinical studies that will allow the therapeutic value of nanotechnology-based restorative materials to be established. PMID:23810638

  20. Nanotechnology-based restorative materials for dental caries management.

    PubMed

    Melo, Mary A S; Guedes, Sarah F F; Xu, Hockin H K; Rodrigues, Lidiany K A

    2013-08-01

    Nanotechnology has been applied to dental materials as an innovative concept for the development of materials with better properties and anticaries potential. In this review we discuss the current progress and future applications of functional nanoparticles incorporated in dental restorative materials as useful strategies to dental caries management. We also overview proposed antimicrobial and remineralizing mechanisms. Nanomaterials have great potential to decrease biofilm accumulation, inhibit the demineralization process, to be used for remineralizing tooth structure, and to combat caries-related bacteria. These results are encouraging and open the doors to future clinical studies that will allow the therapeutic value of nanotechnology-based restorative materials to be established.

  1. Interpreting finite element results for brittle materials in endodontic restorations

    PubMed Central

    2011-01-01

    Background Finite element simulation has been used in last years for analysing the biomechanical performance of post-core restorations in endodontics, but results of these simulations have been interpreted in most of the works using von Mises stress criterion. However, the validity of this failure criterion for brittle materials, which are present in these restorations, is questionable. The objective of the paper is to analyse how finite element results for brittle materials of endodontic restorations should be interpreted to obtain correct conclusions about the possible failure in the restoration. Methods Different failure criteria (Von Mises, Rankine, Coulomb-Mohr, Modified Mohr and Christensen) and material strength data (diametral tensile strength and flexural strength) were considered in the study. Three finite element models (FEM) were developed to simulate an endodontic restoration and two typical material tests: diametral tensile test and flexural test. Results Results showed that the Christensen criterion predicts similar results as the Von Mises criterion for ductile components, while it predicts similar results to all other criteria for brittle components. The different criteria predict different failure points for the diametral tensile test, all of them under multi-axial stress states. All criteria except Von Mises predict failure for flexural test at the same point of the specimen, with this point under uniaxial tensile stress. Conclusions From the results it is concluded that the Christensen criterion is recommended for FEM result interpretation in endodontic restorations and that the flexural test is recommended to estimate tensile strength instead of the diametral tensile test. PMID:21635759

  2. Effect of two restorative materials on root dentine erosion.

    PubMed

    Domiciano, Silvia Jorge; Colucci, Vivian; Serra, Mônica Campos

    2010-05-01

    This study sought to evaluate the microhardness of root dentine adjacent to glass-ionomer and composite resin restorations after erosive challenge. A crossover study was performed in two phases of 4 consecutive days each. One hundred twelve bovine root dentine slabs were obtained, and standardized box-shaped cavities were prepared at center of each specimen. The prepared cavities were randomly restored with glass-ionomer cement or composite resin. The slabs were randomly assigned among 14 volunteers, which wore intraoral palatal device containing four restored root dentin slabs. Starting on the second day, half of the palatal acrylic devices were immersed extraorally in a lemonade-like carbonated soft drink for 90 s, four times daily for 3 days. After 3-day wash-out, dentine slabs restored with the alternative material were placed into palatal appliance and the volunteers started the second phase of this study. After erosive challenges, microhardness measurements were performed. Regardless of the restorative material employed, eroded specimens demonstrated lower microhardness value (p < 0.0001). At eroded condition examined in this study, dentine restored with glass-ionomer cement showed higher microhardness values (p < 0.0001). It may be concluded that the glass-ionomer cement decreases the progression of root dentine erosion at restoration margin.

  3. Composite resin: a versatile, multi-purpose restorative material.

    PubMed

    Margeas, Robert

    2012-01-01

    Introduced more than some 50 years ago, composite resin technology has simplified the manner in which clinicians practice restorative dentistry, offering greater predictability and improved physical properties. Decades of material science and laboratory development along with clinical trials in human subjects have culminated in composite resin being validated as a reliable, multifunctional restorative material. With a wide range of composite resins available today, clinicians can benefit from knowing the infrastructure of a given material in order to determine which type will work best in a particular clinical situation.

  4. Annotated Bibliography of Textbooks and Reference Materials in Marine Sciences. Provisional Edition. Intergovernmental Oceanographic Commission, Technical Series.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific, and Cultural Organization, Paris (France). Intergovernmental Oceanographic Commission.

    Presented is an annotated bibliography based on selected materials from a preliminary survey of existing bibliographies, publishers' listings, and other sources. It is intended to serve educators and researchers, especially those in countries where marine sciences are just developing. One hundred annotated and 450 non-annotated entries are…

  5. Recent Advances and Developments in Composite Dental Restorative Materials

    PubMed Central

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

    2011-01-01

    Composite dental restorations represent a unique class of biomaterials with severe restrictions on biocompatibility, curing behavior, esthetics, and ultimate material properties. These materials are presently limited by shrinkage and polymerization-induced shrinkage stress, limited toughness, the presence of unreacted monomer that remains following the polymerization, and several other factors. Fortunately, these materials have been the focus of a great deal of research in recent years with the goal of improving restoration performance by changing the initiation system, monomers, and fillers and their coupling agents, and by developing novel polymerization strategies. Here, we review the general characteristics of the polymerization reaction and recent approaches that have been taken to improve composite restorative performance. PMID:20924063

  6. Finite element calculation of residual stress in dental restorative material

    NASA Astrophysics Data System (ADS)

    Grassia, Luigi; D'Amore, Alberto

    2012-07-01

    A finite element methodology for residual stresses calculation in dental restorative materials is proposed. The material under concern is a multifunctional methacrylate-based composite for dental restorations, activated by visible light. Reaction kinetics, curing shrinkage, and viscoelastic relaxation functions were required as input data on a structural finite element solver. Post cure effects were considered in order to quantify the residual stresses coming out from natural contraction with respect to those debited to the chemical shrinkage. The analysis showed for a given test case that residual stresses frozen in the dental restoration at uniform temperature of 37°C are of the same order of magnitude of the strength of the dental composite material per se.

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

    PubMed

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

    2011-04-01

    Composite dental restorations represent a unique class of biomaterials with severe restrictions on biocompatibility, curing behavior, esthetics, and ultimate material properties. These materials are presently limited by shrinkage and polymerization-induced shrinkage stress, limited toughness, the presence of unreacted monomer that remains following the polymerization, and several other factors. Fortunately, these materials have been the focus of a great deal of research in recent years with the goal of improving restoration performance by changing the initiation system, monomers, and fillers and their coupling agents, and by developing novel polymerization strategies. Here, we review the general characteristics of the polymerization reaction and recent approaches that have been taken to improve composite restorative performance. PMID:20924063

  8. Microleakage reduction from newer esthetic restorative materials in permanent molars.

    PubMed

    Ferdianakis, K

    1998-01-01

    Through use of new technologies, such as air-abrasive devices, caries detector dyes, modern technology can increase the speed, comfort and success of dental restorations. However the issue of marginal adaptation has been an ongoing technical problem. Today with the more frequent use of posterior composite resins, poor marginal adaptation of resin is still the major cause of failure of the restoration. Material contraction from polymerization and possibly inappropriate preparation design are key factors in the longevity of the restorations. This study attempts to determine the more effective material and technique for reducing microleakage in composite restorations. An in vitro study using three hybrid composite resins was done to evaluate marginal microleakage. Extracted molars were chosen and evaluated for caries through the use of caries detector dye. Using air-abrasion, caries were removed and minimal preparations were done. The samples were divided into two groups. First group was restored with Herculite XRV and Heliomolar paste composites resins. The second group was restored with Revolution flowable composite resin. Also Opti-bond and Fortify were used as a bonding agent and surface penetrating sealant respectively. The teeth were properly finished, thermocycled and evaluated for leakage using 2% basic fuschin detector dye. All data were subjected to the nonparametric Mann-Whitney Rank Sum Test. The results revealed that Herculite XRV and Heliomolar paste composites had significantly higher microleakage formation (P < 0.03), and also they presented higher void formation (P < 0.0001) than Revolution flowable composite resin.

  9. Resin-based composite as a direct esthetic restorative material.

    PubMed

    Malhotra, Neeraj; Mala, Kundabala; Acharya, Shashirashmi

    2011-06-01

    The search for an ideal esthetic material for tooth restoration has resulted in significant improvements in both materials and the techniques for using them. Various resin-based composite (RBC) materials have recently been introduced into the market that offer improved esthetic and physical properties. This article reviews RBCs, including their compositions, advantages, and disadvantages, that are contemporary to today's clinical practice as well as those that are under research consideration and/ or in clinical trial phase.

  10. Influence of Photoactivation Source on Restorative Materials and Enamel Demineralization

    PubMed Central

    Popoff, Josiane Marques de Sena; Rodrigues, José Augusto; Aras, Wanessa Maria De Freitas

    2014-01-01

    Abstract Objective: The objective of this study was to evaluate the influence of the photoactivation source on the polymerization depth of restorative materials and its effects on resistance to enamel demineralization. Background data: Argon-ion laser (AL) irradiation itself provides a reduced depth of caries lesions in sound enamel. Methods: Eighteen human teeth were sectioned into 36 blocks and distributed into two groups according to the respective restorative material: resin-modified glass ionomer material (RMGI) (Vitremer-3M ESPE; A3; n=18) and composite resin (CR) (Z350-3M ESPE; n=18). Each group was subdivided into three subgroups and activated by a quartz-tungsten-halogen (QTH) lamp, an AL, or a light-emitting diode (LED) (n=6). Knoop microhardness (KHN) analysis of the materials was evaluated at two different depths: 0 and 1.6 mm from the enamel surface. The blocks were thermocycled and submitted to five demineralization–remineralization cycles at 37°C. The KHN values of the enamel surface (0 mm) were evaluated. The specimens were longitudinally sectioned, and the restorative material was evaluated at a depth of 1.6 mm. Data were evaluated by two way analysis of variance (ANOVA) and Tukey tests (p<0.05). The evaluation of subsuperficial enamel demineralization by KHN analysis was conducted by seven indentations located at 100 μm from the restored cavity. Data were evaluated by three way ANOVA and Tukey tests (p<0.05). Results: Comparing the two restorative materials, the KHN values at the surface (0 mm) were greater for CR, whereas at 1.6 mm, they were greater for RMGI. In addition, there was less development of enamel demineralization around RMGI restorations than CR restorations. Moreover, there were statistically significant differences on subsuperficial enamel demineralization between the two restorative materials and between the three photoactivation methods (p<0.05); RMGI presented the highest KHN values, and QTH and AL presented the

  11. Cuspal Movement and Microleakage in Premolar Teeth Restored with Posterior Restorative Materials

    PubMed Central

    Garapati, Surendranath; Das, Maneesha; Mujeeb, Abdul; Dey, Subhra; Kiswe, Santosh Panditrao

    2014-01-01

    Background: With the increase in various resin-based composites with varying monomeric formulations and fi llers had led to a significant number of problems, and one of such is postoperative pain. Clinician is in a dilemma what to select and what not to. The latest nanocomposite is there for a short while that no individual research is available currently, hence, this study was undertaken. The aim of this present study was to assess the cuspal deflection at each stage of polymerization for the incremental restoration of standardized large (mesio occlusal distal [MOD]) cavities with three posterior restorative resins. And also to assess the cervical microleakage. Materials and Methods: 18 extracted upper premolar teeth were selected. Teeth were divided into three groups (A, B, and C), each group consisting six teeth, large (MOD) cavity preparation was done. Groups A, B, and C were restored with P60, Filtek supreme (3M, ESPE), and ormocer material (Admira:Voco). The lingual cusps of the extracted teeth were approximated to the receptor of a compactor - deflection measuring gauge, following each stage of polymerization using light emitting diode curing light a measurement of the cuspal deflection was recorded. The restored teeth were prepared for microleakage testing and were examined under stereomicroscope at ×25 for the extent of the cervical gingival microleakage. Results: The cuspal deflection was the greatest for Filtek P60 and least for filtek supreme - nanocomposite with ormocer ranked between the two. For the microleakage, none of the materials were identified as producing less gingival microleakage. Conclusion: The lesser cuspal deflection values with filtek supreme nanocomposite could be due to resin chemistry and also filler particle size. Hence, this nanocomposite could be the first choice of material for use in large esthetic restorations. PMID:25395793

  12. Swedish dentists' decisions on preparation techniques and restorative materials.

    PubMed

    Sundberg, H; Mejàre, I; Espelid, I; Tveit, A B

    2000-06-01

    This study aimed at mapping the preparation techniques and restorative materials that Swedish dentists are using for primary approximal and occlusal carious lesions. It involved sending a pre-coded questionnaire to a random sample of 923 dentists, with eight items concerning approximal and occlusal restorative preparation techniques and dental materials. Responses were received from 651 (70.5%) dentists. To restore a primary approximal carious lesion in an adolescent with low caries activity and good oral hygiene, the tunnel preparation was chosen by 48% of the dentists, the saucer-shaped preparation by 32%, and the traditional Class II preparation by 20%. The most common preparation technique for restoring an occlusal carious lesion was removal of the carious part only, which was chosen by 74% of the dentists. For a lower second molar with a minor occlusal caries lesion combined with a suspected dentin lesion as judged radiographically, about half of the dentists chose to restore the carious part only and 27% would seal the rest of the fissure system in addition. For a similar lesion with no obvious radiolucency in the dentin, about 1/3 chose the 'no treatment' alternative, 1/3 fluoride treatment, and the rest fissure sealing or other techniques. Composite was used most often and amalgam least often for both approximal and occlusal carious lesions.

  13. Materials and methods for autonomous restoration of electrical conductivity

    DOEpatents

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

    2014-03-25

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

  14. Association between caries location and restorative material treatment provided

    PubMed Central

    Lubisich, Erinne B.; Hilton, Thomas J.; Ferracane, Jack L.; Pashova, Hristina I.; Burton, Bruce

    2013-01-01

    Objectives This cross-sectional study by the Northwest PRECEDENT practitioners correlated the location of caries diagnosed in the past 12 months with treatment provided. Methods An oral health survey was conducted on up to 20 patients per practice for 101 practices in the Northwest PRECEDENT network. A total of 1943 eligible patients were randomly assessed for the location of and treatment provided for caries lesions diagnosed within the past 12 months. Regression analysis using Generalized Estimating Equations (GEE) was performed to assess association of treatment to tooth location and surface characterization, adjusting for age, practice location (urban/rural), dentist gender, and experience level. The analysis accounts for clustering by practice using robust variance estimates. Results Overall, 55.4% of patients exhibited recent caries and 42.8% received treatment for at least one permanent tooth. 18% of treated teeth were treated with amalgam, and 72% were treated with composite. This percentage varied as a function of tooth surface characteristics, patient characteristics, and dentist characteristics. The results suggest that restoration selection does depend on tooth type and which surfaces are being restored. The odds of a molar receiving an amalgam restoration are 2.44 (95% CI=1.81–3.30) times higher as compared to a bicuspid, adjusting for all other covariates. When the restoration includes the occlusal surface of a tooth the odds are 0.42 (95% CI=0.20–0.89) times as great that amalgam will be placed. When the restoration includes the mesial or distal surface of the tooth the odds for amalgam restoration are 2.49 (95% CI=1.25–4.95) times higher compared to when it does not include these surfaces. Conclusion Restorative material choice varied based on caries location and practitioner gender. PMID:21256915

  15. Gradual surface degradation of restorative materials by acidic agents.

    PubMed

    Hengtrakool, Chanothai; Kukiattrakoon, Boonlert; Kedjarune-Leggat, Ureporn

    2011-01-01

    The aim of this study was to investigate the effect of acidic agents on surface roughness and characteristics of four restorative materials. Fifty-two discs were created from each restorative material: metal-reinforced glass ionomer cement (Ketac-S), resin-modified glass ionomer cement (Fuji II LC), resin composite (Filtek Z250), and amalgam (Valiant-PhD); each disc was 12 mm in diameter and 2.5 mm thick. The specimens were divided into four subgroups (n=13) and immersed for 168 hours in four storage media: deionized water (control); citrate buffer solution; green mango juice; and pineapple juice. Surface roughness measurements were performed with a profilometer, both before and after storage media immersion. Surface characteristics were examined using scanning electron microscopy (SEM). Statistical significance among each group was analyzed using two-way repeated ANOVA and Tukey's tests. Ketac-S demonstrated the highest roughness changes after immersion in acidic agents (p<0.05), followed by Fuji II LC. Valiant-PhD and Filtek Z250 illustrated some minor changes over 168 hours. The mango juice produced the greatest degradation effect of all materials tested (p<0.05). SEM photographs demonstrated gradual surface changes of all materials tested after immersions. Of the materials evaluated, amalgam and resin composite may be the most suitable for restorations for patients with tooth surface loss.

  16. Gradual surface degradation of restorative materials by acidic agents.

    PubMed

    Hengtrakool, Chanothai; Kukiattrakoon, Boonlert; Kedjarune-Leggat, Ureporn

    2011-01-01

    The aim of this study was to investigate the effect of acidic agents on surface roughness and characteristics of four restorative materials. Fifty-two discs were created from each restorative material: metal-reinforced glass ionomer cement (Ketac-S), resin-modified glass ionomer cement (Fuji II LC), resin composite (Filtek Z250), and amalgam (Valiant-PhD); each disc was 12 mm in diameter and 2.5 mm thick. The specimens were divided into four subgroups (n=13) and immersed for 168 hours in four storage media: deionized water (control); citrate buffer solution; green mango juice; and pineapple juice. Surface roughness measurements were performed with a profilometer, both before and after storage media immersion. Surface characteristics were examined using scanning electron microscopy (SEM). Statistical significance among each group was analyzed using two-way repeated ANOVA and Tukey's tests. Ketac-S demonstrated the highest roughness changes after immersion in acidic agents (p<0.05), followed by Fuji II LC. Valiant-PhD and Filtek Z250 illustrated some minor changes over 168 hours. The mango juice produced the greatest degradation effect of all materials tested (p<0.05). SEM photographs demonstrated gradual surface changes of all materials tested after immersions. Of the materials evaluated, amalgam and resin composite may be the most suitable for restorations for patients with tooth surface loss. PMID:21903509

  17. [Microleakage in class V cavities restored with esthetic materials, using different restorative techniques].

    PubMed

    Russo, E M; de Carvalho, R C; Matson, E; dos Santos, R S

    2001-01-01

    The purpose of this study was to compare the microleakage of class V cavities restored with composite resin (CR), resin-modified glass ionomer cement (RMGIC) and polyacid-modified resin composite (PAMRC), using different clinical procedures. Thirty-six noncarious human molars were used in this study. A class V cavity, measuring approximately 3 mm x 4 mm x 2 mm, was prepared in each tooth in both buccal and lingual aspects, with a diamond bur (number 1,093) at high speed, with coolant water spray. The occlusal margin was located on enamel and the gingival margin was located on dentin. The teeth were divided into 9 groups with 8 specimens each. The cavities were restored according to different techniques. The specimens from groups 1, 2, 4 and 5 did not receive acid etching. The samples were stored in water at 37 degrees C for 24 hours, subjected to occlusal load, thermocycled and immersed in rhodamine B. The restorations were then washed and sectioned in buccolingual direction. The depth of dye penetration was scored from zero (no leakage) to 3 (maximum leakage). The Kruskal-Wallis test revealed statistically significant differences between the materials (p < 0.05). PAMRC used without acid etching showed the greatest score of leakage in both margins. In the gingival margin, CR showed scores of leakage lower than those of PAMRC and RMGIC. Additional retentions and acid etching were able to decrease microleakage in PAMRC restorations in both gingival and occlusal margins.

  18. Overview: Damage resistance of graded ceramic restorative materials

    PubMed Central

    Zhang, Yu

    2012-01-01

    Improving mechanical response of materials is of great interest in a wide range of disciplines, including biomechanics, tribology, geology, optoelectronics, and nanotechnology. It has been long recognized that spatial gradients in surface composition and structure can improve the mechanical integrity of a material. This review surveys recent results of sliding-contact, flexural, and fatigue tests on graded ceramic materials from our laboratories and elsewhere. Although our findings are examined in the context of possible applications for next-generation, graded all-ceramic dental restorations, implications of our studies have broad impact on biomedical, civil, structural, and an array of other engineering applications. PMID:22778494

  19. Overview: Damage resistance of graded ceramic restorative materials.

    PubMed

    Zhang, Yu

    2012-08-01

    Improving mechanical response of materials is of great interest in a wide range of disciplines, including biomechanics, tribology, geology, optoelectronics, and nanotechnology. It has been long recognized that spatial gradients in surface composition and structure can improve the mechanical integrity of a material. This review surveys recent results of sliding-contact, flexural, and fatigue tests on graded ceramic materials from our laboratories and elsewhere. Although our findings are examined in the context of possible applications for next-generation, graded all-ceramic dental restorations, implications of our studies have broad impact on biomedical, civil, structural, and an array of other engineering applications.

  20. Recent Advances in Materials for All-Ceramic Restorations

    PubMed Central

    Griggs, Jason A.

    2010-01-01

    SYNOPSIS The past three years of research on materials for all-ceramic veneers, inlays, onlays, single-unit crowns, and multi-unit restorations are reviewed. The primary changes in the field were the proliferation of zirconia-based frameworks and computer-aided fabrication of prostheses, as well as, a trend toward more clinically relevant in vitro test methods. This report includes an overview of ceramic fabrication methods, suggestions for critical assessment of material property data, and a summary of clinical longevity for prostheses constructed of various materials. PMID:17586152

  1. The material science of minimally invasive esthetic restorations.

    PubMed

    Nový, Brian B; Fuller, Cameron E

    2008-01-01

    The term esthetic dentistry usually conjures up mental images of porcelain crowns and veneers. To some dentists, the term minimally invasive dentistry evokes thoughts of observing early lesions, and postponing treatment until lesions are closer to the pulp. (The World Congress of Minimally Invasive Dentistry defines minimally invasive dentistry as those techniques which respect health, function, and esthetics of oral tissue by preventing disease from occurring, or intercepting its progress with minimal tissue loss.) It would seem these two niches within dentistry are on opposite ends of the spectrum; however, composite resin and glass ionomer restorative materials unite these two ideologies. Understanding the limitations, benefits, and science behind each material allows clinicians to produce highly esthetic restorations that can resist future decay, internally remineralize the tooth, and help protect adjacent teeth from cariogenic attack.

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

    PubMed

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

    2011-01-01

    This study evaluated the effect of a high-concentration carbamide peroxide–containing home bleaching system (Opalescence PF) and a hydrogen peroxide–containing over-the-counter bleaching system (Treswhite Supreme) on the microhardness of two nanocomposites (Filtek Supreme XT and Premise) and leucite-reinforced glass ceramic (Empress Esthetic), glass ceramic (Empress 2 layering), and feldspathic porcelain (Matchmaker MC). A total of 100 specimens, 20 of each kind of the restorative materials, 2 mm in thickness and 10 mm in diameter, were fabricated. Then the specimens were polished with SiC paper and 1 μm alumina polishing paste. After polishing, porcelain specimens were glazed in accordance with the manufacturer's instructions. Each type of restorative material was then randomly divided into two groups (n=10), and the specimens were treated with either Opalescence PF or Treswhite Supreme. The microhardness of the specimens before bleaching (baseline) and after bleaching was determined using a digital microhardness tester. Data were analyzed using the Mann-Whitney U-test and the Wilcoxon test. Opalescence PF significantly influenced the hardness of all the restorative materials. Statistically significant decreases with respect to before bleaching were found for Premise (p=0.005), Empress Esthetic (p=0.003), Empress 2 layering (p=0.005), and Matchmaker-MC (p=0.003), whereas a statistically significant increase was observed in Filtek Supreme XT (p=0.028). The difference in the microhardness values between before and after bleaching using Treswhite Supreme was statistically significant only for Premise (p=0.022). High-concentration carbamide peroxide–containing home bleaching may affect the microhardness of restorative materials. PMID:21702674

  3. Finite element analysis of stress concentration in Class V restorations of four groups of restorative materials in mandibular premolar

    PubMed Central

    N, Shubhashini; N, Meena; Shetty, Ashish; Kumari, Anitha; DN, Naveen

    2008-01-01

    Aim: To study the concentration of stress in class V restoration of four different restorative materials subjected to occlusal load of 100N, 150N, 200N, 250N and to analyse the obtained data with the listed properties of the restorative material. Materials and Methods: Using FEM analysis the stresses generated in a class V lesion in a mandibular premolar was studied. Results: Within the framework of the aforementioned views, and from the results of the study it can be concluded that microfilled composite is the most suitable restorative material followed by flowable composite, glass ionomer cement and resin modified glass ionomer cement. Conclusion: Restoration of Class V lesions with materials of higher modulus of elasticity will enable better stress distribution. PMID:20142899

  4. Evaluation of hardness and wear resistance of interim restorative materials

    PubMed Central

    Savabi, Omid; Nejatidanesh, Farahnaz; Fathi, Mohamad Hossein; Navabi, Amir Arsalan; Savabi, Ghazal

    2013-01-01

    Background: The interim restorative materials should have certain mechanical properties to withstand in oral cavity. The aim of this study was to evaluate the hardness and wear resistance of interim restorative materials. Materials and Methods: Fifteen identical rectangular shape specimens with dimensions of 2 mm × 10 mm × 30 mm were made from 7 interim materials (TempSpan, Protemp 3 Garant, Revotek, Unifast LC, Tempron, Duralay, and Acropars). The Vickers hardness and abrasive wear of specimens were tested in dry conditions and after 1 week storage in artificial saliva. The depth of wear was measured using surface roughness inspection device. Data were subjected to Kruskal–Wallis and Mann–Whitney tests. The Pearson correlation coefficient was used to determine the relationship between hardness and wear (α =0.05). Results: TempSpan had the highest hardness. The wear resistance of TempSpan (in dry condition) and Revotek (after conditioning in artificial saliva) was significantly higher (P < 0.05). There was no statistically significant correlation between degree of wear and hardness of the materials (P = 0.281, r = −0.31). Conclusion: Hardness and wear resistance of interim resins are material related rather than category specified. PMID:23946734

  5. Finite element stress analysis of short-post core and over restorations prepared with different restorative materials.

    PubMed

    Gurbuz, Taskin; Sengul, Fatih; Altun, Ceyhan

    2008-07-01

    The present study was conducted to determine the effect on the distribution of stress with the use of short-post cores and over restorations composed of different materials. The restorative materials used were namely two different composite resin materials (Valux Plus and Tetric Flow), a polyacid-modified resin material (Dyract AP), and a woven polyethylene fiber combination (Ribbond Fiber + Bonding agent + Tetric Flow). Finite element analysis (FEA) was used to develop a model for the maxillary primary anterior teeth. A masticatory force of 100 N was applied at 148 degrees to the incisal edge of the palatal surface of the crown model. Stress distributions and stress values were compared using von Mises criteria. The tooth model was assumed to be isotropic, homogeneous, elastic, and asymmetrical. It was observed that the highest stress usually occurred in the cervical area of the tooth when Tetric Flow was used as the short-post core and over restoration material. The same maximum stress value was also obtained when Ribbond fiber + Tetric Flow material was used for the short-post core. The results of FEA showed that the mechanical properties and elastic modulus of the restorative material influenced the stresses generated in enamel, dentin, and restoration when short-post core restorations were loaded incisally. Resin-based restorative materials with higher elastic moduli were found to be unsuitable as short-post core materials in endodontically treated maxillary primary anterior teeth. PMID:18833762

  6. Finite element stress analysis of short-post core and over restorations prepared with different restorative materials.

    PubMed

    Gurbuz, Taskin; Sengul, Fatih; Altun, Ceyhan

    2008-07-01

    The present study was conducted to determine the effect on the distribution of stress with the use of short-post cores and over restorations composed of different materials. The restorative materials used were namely two different composite resin materials (Valux Plus and Tetric Flow), a polyacid-modified resin material (Dyract AP), and a woven polyethylene fiber combination (Ribbond Fiber + Bonding agent + Tetric Flow). Finite element analysis (FEA) was used to develop a model for the maxillary primary anterior teeth. A masticatory force of 100 N was applied at 148 degrees to the incisal edge of the palatal surface of the crown model. Stress distributions and stress values were compared using von Mises criteria. The tooth model was assumed to be isotropic, homogeneous, elastic, and asymmetrical. It was observed that the highest stress usually occurred in the cervical area of the tooth when Tetric Flow was used as the short-post core and over restoration material. The same maximum stress value was also obtained when Ribbond fiber + Tetric Flow material was used for the short-post core. The results of FEA showed that the mechanical properties and elastic modulus of the restorative material influenced the stresses generated in enamel, dentin, and restoration when short-post core restorations were loaded incisally. Resin-based restorative materials with higher elastic moduli were found to be unsuitable as short-post core materials in endodontically treated maxillary primary anterior teeth.

  7. Penetration of the pulp chamber by bleaching agents in teeth restored with various restorative materials.

    PubMed

    Gökay, O; Yilmaz, F; Akin, S; Tunçbìlek, M; Ertan, R

    2000-02-01

    It is thought that externally applied bleaching agents may penetrate into the pulp chamber. This study was conducted to evaluate the diffusion of peroxide bleaching agents into the pulp chamber of teeth restored with various restorative materials. Sixty-five human extracted anterior maxillary teeth were separated into the 13 groups containing 5 teeth. Five teeth (control group) were not subjected to any cavity preparation and restoration. Standardized class V cavities were prepared in the other 60 teeth and restored using composite resin (Charisma), polyacid modified composite resin (Dyract), or resin-modified glass ionomer cement (Vitremer). All teeth were sectioned 3 mm apical to the cementoenamel junction to remove the intracoronal pulp tissue, and the pulp chamber was filled with acetate buffer to absorb and stabilize any peroxide that might penetrate. Vestibular crown surfaces of teeth in the experimental groups were subjected to four different bleaching agents for 30 min at 37 degrees C, whereas the teeth in the control groups were exposed only to distilled water. Then the acetate buffer solution in the pulp chamber of each tooth was removed, and the pulp chamber of each tooth was rinsed with 100 ml of distilled water twice. Leukocrystal violet and enzyme horseradish peroxidase were added to the mixture of the acetate buffer and rinse water. The optical density of the resulting blue solution was determined spectrophotometrically and converted into microgram equivalents of hydrogen peroxide. Higher hydrogen peroxide concentrations resulted in a higher pulpal peroxide penetration. The highest pulpal peroxide penetration was found in resin-modified glass ionomer cement groups, whereas composite resin groups showed the lowest pulpal peroxide penetration. PMID:11194380

  8. A revised classification for direct tooth-colored restorative materials.

    PubMed

    Mount, Graham J; Tyas, Martin J; Ferracane, Jack L; Nicholson, John W; Berg, Joel H; Simonsen, Richard J; Ngo, Hien C

    2009-09-01

    Composite resins and glass-ionomer cements were introduced to dentistry in the 1960s and 1970s, respectively. Since then, there has been a series of modifications to both materials as well as the development other groups claiming intermediate characteristics between the two. The result is a confusion of materials leading to selection problems. While both materials are tooth-colored, there is a considerable difference in their properties, and it is important that each is used in the appropriate situation. Composite resin materials are esthetic and now show acceptable physical strength and wear resistance. However, they are hydrophobic, and therefore more difficult to handle in the oral environment, and cannot support ion migration. Also, the problems of gaining long-term adhesion to dentin have yet to be overcome. On the other hand, glass ionomers are water-based and therefore have the potential for ion migration, both inward and outward from the restoration, leading to a number of advantages. However, they lack the physical properties required for use in load-bearing areas. A logical classification designed to differentiate the materials was first published by McLean et al in 1994, but in the last 15 years, both types of material have undergone further research and modification. This paper is designed to bring the classification up to date so that the operator can make a suitable, evidence-based, choice when selecting a material for any given situation.

  9. Esthetic restorative material shade changes due to photopolymerization.

    PubMed

    Watanabe, Hidehiko; Covey, David

    2008-05-01

    This study sought to measure color values (before and after photopolymerization) and variations of A1 shade polymeric dental restorative materials. The L*a*b* values of polymeric dental restorative material disks were measured by a spectrophotometer with the specular component excluded (SCE) geometry under D65 illumination over a standardized white background before and after photopolymerization. Color differences (DeltaE*ab) due to polymerization were calculated using the CIE Lab color-difference formula. DeltaE*ab indicates differences between two colors in the L*a*b* color space. In this system, L*, a*, and b* indicate lightness, red-green, and yellow-blue, respectively. Color differences (DeltaE*ab) were calculated by the equation DeltaE*ab = [(DeltaL*)2 + (Deltaa*)2 + (Deltab*)2]1/2. Eight resin composites, three flowable resin composites (FRCs), and two resin-modified glass ionomers (RMGIs) were utilized; L*a*b* and DeltaE*ab values of the test groups were analyzed using ANOVA and Newman-Keuls multiple comparison tests. DeltaE*ab values before and after photopolymerization ranged from 3.01-17.76. All RMGI and two FRC materials displayed greater color changes than the resin composites (p < 0.05). Photopolymerization produced measurable increases and decreases in lightness. Yellow-blue (b*) values decreased in all test groups after polymerization, while most red-green (a*) values increased. Color differences between polymerized A1 shade materials ranged from 0.76-25.41 DeltaE*ab. The color difference between the test materials and a widely used tooth shade guide (the Vita Lumin) was averaged at 12.66 DeltaE*ab.

  10. Color of restorative materials after staining and bleaching.

    PubMed

    Fay, R M; Servos, T; Powers, J M

    1999-01-01

    This study determined the effect of a 10% carbamide peroxide bleaching agent on the removal of stain from restorative materials. Color changes (delta E*) of three restorative materials [compomer (Dyract); composite (TPH Spectrum); hybrid ionomer (Fuji II LC)] when exposed to juice/tea, chlorhexidine (CH), and water (control) for 120 hours were studied. Stained specimens were treated for two 2-hour periods with a bleaching agent (Platinum Tooth Whitening System) with and without the active ingredient. Color was measured at baseline, after staining, and after treatment using the CIE L*a*b* color system relative to CIE standard illuminant A (incandescent light) as measured by a reflection spectrophotometer. Means and standard deviations (n = 5) were calculated and data were analyzed by four-way ANOVA. All variables and interactions were statistically significant. Color changes caused by CH and water were not perceptible (delta E* < 3.3). After two 2-hour treatments, the following occurred with specimens stained with cranberry juice/tea: paste with and without active ingredient perceptibly changed color of stained composite. The stained hybrid ionomer perceptibly changed color after treatment with paste containing active ingredient but did not change after exposure to paste without active ingredient. The stained compomer was not perceptibly different with either treatment. Platinum successfully removed stains from the composite and hybrid ionomer tested. PMID:10823076

  11. Colour measurements of surfaces to evaluate the restoration materials

    NASA Astrophysics Data System (ADS)

    Lo Monaco, Angela; Marabelli, Maurizio; Pelosi, Claudia; Picchio, Rodolfo

    2011-06-01

    In this paper two case studies on the application of colour measurements for the evaluation of some restoration materials are discussed. The materials related to the research are: watercolours employed in restoration of wall paintings and preservative/consolidants for wood artifacts. Commercial watercolours, supplied by Maimeri, Windsor&Newton and Talens factories have been tested. Colour measurements have been performed by means of a reflectance spectrophotometer (RS) before and after accelerated ageing of watercolours at 92% relative humidity (RH) and in a Solar Box chamber. The experimental results show that watercolours based on natural earths and artificial ultramarine undergo the main colour changes, expressed as L*, a* and b* variations and total colour difference (▵E*). In the other cases colour differences depend on both watercolour typology and suppliers. The other example concerns the evaluation of colour change due to surface treatment of Poplar (Populus sp.) and chestnut (Castanea sativa L.) wood samples. The wooden samples have been treated with a novel organic preservative/consolidant product that has been tested also in a real case as comparison. The treated samples have been artificially aged in Solar Box chamber equipped with a 280 nm UV filter. Colour has been measured before and after the artificial ageing by means of a RS. Colour changes have been determined also for the main door of an historical mansion in Viterbo, made of chestnut wood, and exposed outdoors.

  12. Criteria for clinical translucency evaluation of direct esthetic restorative materials

    PubMed Central

    2016-01-01

    The purpose of this review was to suggest practical criteria for the clinical translucency evaluation of direct esthetic restorative materials, and to review the translucency with these criteria. For the evaluation of reported translucency values, measuring instrument and method, specimen thickness, background color, and illumination should be scrutinized. Translucency parameter (TP) of 15 to 19 could be regarded as the translucency of 1 mm thick human enamel. Visual perceptibility threshold for translucency difference in contrast ratio (ΔCR) of 0.07 could be transformed into ΔTP value of 2. Translucency differences between direct and indirect resin composites were perceivable (ΔTP > 2). Universal and corresponding flowable resin composites did not show perceivable translucency differences in most products. Translucency differed significantly by the product within each shade group, and by the shade group within each product. Translucency of human enamel and perceptibility threshold for translucency difference may be used as criteria for the clinical evaluation of translucency of esthetic restorative materials. PMID:27508156

  13. Criteria for clinical translucency evaluation of direct esthetic restorative materials.

    PubMed

    Lee, Yong-Keun

    2016-08-01

    The purpose of this review was to suggest practical criteria for the clinical translucency evaluation of direct esthetic restorative materials, and to review the translucency with these criteria. For the evaluation of reported translucency values, measuring instrument and method, specimen thickness, background color, and illumination should be scrutinized. Translucency parameter (TP) of 15 to 19 could be regarded as the translucency of 1 mm thick human enamel. Visual perceptibility threshold for translucency difference in contrast ratio (ΔCR) of 0.07 could be transformed into ΔTP value of 2. Translucency differences between direct and indirect resin composites were perceivable (ΔTP > 2). Universal and corresponding flowable resin composites did not show perceivable translucency differences in most products. Translucency differed significantly by the product within each shade group, and by the shade group within each product. Translucency of human enamel and perceptibility threshold for translucency difference may be used as criteria for the clinical evaluation of translucency of esthetic restorative materials. PMID:27508156

  14. Embryotoxicity assays for leached components from dental restorative materials

    PubMed Central

    2011-01-01

    Background Currently, there are no suitable assays available to evaluate the embryotoxicity of leached components from restorative dental materials. Methods The effect of the medium conditioned by composites and amalgam on mouse blastocysts in vitro was tested. The materials were also subcutaneously implanted, and the effect of the medium supplemented with serum from the host blood was evaluated in the embryotoxicity assay. The embryo implantation rate in the material-transplanted mothers was also evaluated. Results The results show that while the culture in media conditioned by amalgams did not affect blastocyst development, the medium conditioned by composites caused blastocyst degeneration and apoptosis. The development of blastocysts in a medium containing serum obtained from animals after transplantation was, however, without effect. Finally, inconsistent reduction in the implantation rate in transplanted mothers was observed. Conclusions In this study, we provide examples of in vitro and in vivo tests that may be used to evaluate embryotoxicity for dental materials. Our results show that leached components from our composite-material induced embryotoxicity in vitro, however, no toxicity was observed when subcutaneously implanted in vivo. This highlights the necessity of integrated in vitro and in vivo tests for valuable predictive estimation of embryotoxicity for complex materials. PMID:21978455

  15. Surface contact fatigue and flexural fatigue of dental restorative materials.

    PubMed

    McCabe, J F; Wang, Y; Braem, M

    2000-06-01

    Antagonistic contact on a dental restoration may produce surface and subsurface stresses leading to fatigue wear as well as to bulk stressing, eventually causing catastrophic failure. It was the aim of the present work to study the outcome of two different approaches to fatigue testing of materials involving either surface contact fatigue or flexural fatigue mechanisms. A range of materials was tested, including conventional glass-ionomers, resin-modified glass-ionomers, poly-acid modified composites, and composites. Materials were prepared and tested using both surface contact and flexural fatigue. The results show that conventional glass-ionomers have the least resistance to fatigue under both regimes while composites have the longest fatigue lives and the highest values of flexural fatigue limit. However, the results also support the fact that catastrophic failure should be investigated separately from surface contact fatigue. Within the group of composite products tested, a hybrid composite material had a significantly greater flexural fatigue limit than a microfilled one, but the latter material had a significantly greater surface contact fatigue life, indicating that wear behavior cannot be predicted from bulk fracture characteristics and vice versa. The process of wear occurs by a combination of a number of fundamental processes, and the contribution fatigue makes will vary according to the environment and nature of the material.

  16. Appropriate use of genetic manipulation for the development of restoration plant materials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The diversity of restoration plant material development approaches reflect a variety of philosophies that represent what should and can be accomplished by restoration. The "natural" approach emphasizes emulation of putative naturally occurring patterns of genetic variation. The "genetically manipu...

  17. In situ reaction kinetic analysis of dental restorative materials

    NASA Astrophysics Data System (ADS)

    Younas, Basma; Samad Khan, Abdul; Muzaffar, Danish; Hussain, Ijaz; Chaudhry, Aqif Anwar; Rehman, Ihtesham Ur

    2013-12-01

    The objective of this study was to evaluate in situ structural and thermal changes of dental restorative materials at periodical time intervals. The commercial materials included zinc oxide eugenol (ZOE), zinc phosphate type I (ZnPO4), glass ionomer cement type II (GIC) and resin-based nano-omposite (Filtek Z350 XT). These materials were processed according to manufacturer's instructions. For the structural analysis Fourier transform infrared spectroscopy (FTIR) was used at high resolution. TGA was used to evaluate thermal weight-loss. The FTIR spectra were collected at periodic time intervals. FTIR spectra showed that with time passing all materials exhibited an increase in peak intensities and a new appearance of shoulders and shifting of peaks for example, ZnPO4 (P-O), ZOE (C═O, C═N, C-O-C), GIC (COO-, C-H, Si-OH), composites (C═O, C═C, C═N, C-N-H). The peaks were replaced by bands and these bands became broader with time interval. Composites showed a degree of conversion and new peaks corresponded to the cross-linking of polymer composites. TGA analysis showed that significant changes in weight loss of set materials were observed after 24 h, where ZOE showed continuous changes in thermal degradation. The spectral changes and thermal degradation with time interval elucidated in situ setting behaviour and understanding of their bonding compatibility with tooth structure and change in relation to time.

  18. An evaluation of accelerated Portland cement as a restorative material.

    PubMed

    Abdullah, D; Ford, T R Pitt; Papaioannou, S; Nicholson, J; McDonald, F

    2002-10-01

    Biocompatibility of two variants of accelerated Portland cement (APC) were investigated in vitro by observing the cytomorphology of SaOS-2 osteosarcoma cells in the presence of test materials and the effect of these materials on the expression of markers of bone remodelling. Glass ionomer cement (GIC), mineral trioxide aggregate (MTA) and unmodified Portland cement (RC) were used for comparison. A direct contact assay was undertaken in four samples of each test material, collected at 12, 24, 48 and 72 h. Cell morphology was observed using scanning electron microscopy (SEM) and scored. Culture media were collected for cytokine quantification using enzyme-linked immunosorbent assay (ELISA). On SEM evaluation, healthy SaOS-2 cells were found adhering onto the surfaces of APC variant, RC and MTA. In contrast, rounded and dying cells were observed on GIC. Using ELISA, levels of interleukin (IL)-1beta, IL-6, IL-18 and OC were significantly higher in APC variants compared with controls and GIC (p<0.01), but these levels of cytokines were not statistically significant compared with MTA. The results of this study provide evidence that both APC variants are non-toxic and may have potential to promote bone healing. Further development of APC is indicated to produce a viable dental restorative material and possibly a material for orthopaedic PMID:12162333

  19. Fluoride release from restorative materials coated with an adhesive.

    PubMed

    Miranda, Letícia Algarves; Weidlich, Patrícia; Samuel, Susana Maria Werner; Maltz, Marisa

    2002-01-01

    The retention of both fluoride resins and resin-modified glass ionomer cements to dental tissues can be improved by the association of an adhesive system which promotes the bonding between the resin component and dentin, forming a hybrid layer. The purpose of this investigation was to evaluate if the presence of the adhesive, being part of the hybrid layer composition, interfered with the fluoride released to tooth tissues. The restorative materials studied were: Vitremer (3M), Heliomolar (Vivadent) and Z100 (3M) using an adhesive application (Scotch Bond MultiPurpose Plus--3M). Ten discs of each material were prepared: 5 were covered with the adhesive and 5 were not. The discs were immersed in individual flasks containing artificial saliva which was changed daily. Fluoride release was measured at days 1, 5, 10, 15 and 20 by a fluoride combined electrode (9609 BN--Orion) coupled to an ion analyzer (SA-720 Procyon). One-way ANOVA and the Student-Newman-Keuls test were applied to compare the materials. The results showed that the use of a dental adhesive significantly decreased the fluoride release of Vitremer and reduced the fluoride release of Heliomolar to undetectable levels with the methodology used. PMID:11870961

  20. The development of ecologically appropriate plant materials for restoration applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Restoration targets are increasingly the novel ecosystems that are rapidly becoming the planetary norm. To be effective, ecological restoration should emphasize ecosystem repair of past damage. When that damage is extensive, local genotypes may not be the ones most effective for repair. 'Local ha...

  1. Classifying dental ceramics: numerous materials and formulations available for indirect restorations.

    PubMed

    Helvey, Gregg A

    2014-01-01

    Because there are numerous ceramic systems available to clinicians for all types of indirect restorations, deciding which system works best for a given clinical situation can be a challenge. Understanding the different classifications of ceramic restoratives can be helpful not only to the clinician but also the dental technician. Manufacturers are constantly introducing newer ceramic materials and improving their existing systems, which has resulted in an increase in all-ceramic restorations and fewer porcelain-to-metal restorations. The classification of ceramic materials remains mostly constant; however, it is subject to change based on newer materials and formulations. The classifications of ceramics are described using several different methods.

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

    PubMed

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

    2011-01-01

    MgO, SiO(2), Al(2)O(3), MgF(2), CaF(2), CaCO(3), SrCO(3), and P(2)O(5) were used to prepare glass-ceramics for restorative dental materials. Thermal properties, phases, microstructures and hardness were characterized by DTA, XRD, SEM and Vickers microhardness. Three-point bending strength and fracture toughness were applied by UTM according to ISO 6872: 1997(E). XRD showed that the glass crystallized at 892°C (second crystallization temperature+20°C) for 3 hrs consisted mainly of calcium-mica and fluorapatite crystalline phases. Average hardness (3.70 GPa) closely matched human enamel (3.20 GPa). The higher fracture toughness (2.04 MPa√m) combined with the hardness to give a lower brittleness index (1.81 µm(-1/2)) which indicates that they have exceptional machinability. Bending strength results (176.61 MPa) were analyzed by Weibull analysis to determine modulus value (m=17.80). Machinability of the calcium mica-fluorapatite glass-ceramic was demonstrated by fabricating with CAD/CAM. PMID:21597218

  3. Photocurability of a new silorane-based restorative material.

    PubMed

    Stefan-Dogar, Dragos; Vandewalle, Kraig S

    2010-01-01

    This study sought to determine how irradiance at various distances affected the hardness of a new silorane-based composite compared to a methacrylate-based composite resin restorative material. A visible-light curing unit was used at low and high irradiances. Plastic molds of various thicknesses (1, 2, 3, and 4 mm) were filled with composite resin and polymerized for 20 seconds at various distances (0, 2, 4, and 6 mm). After 24 hours of storage at 37°C, the microhardness of each specimen was tested at the bottom surface using a microhardness tester. These microhardness values were expressed as a percentage of maximum microhardness and analyzed with ANOVA and Tukey's post-hoc tests. At both low and high irradiances, the silorane-based composite (shade A2) was capable of acceptable (80%) bottom-to-maximum microhardness ratios at increments up to 3 mm and at curing distances up to 4 mm (at low irradiance) and 6 mm (at high irradiance).

  4. Surface characteristics of aesthetic restorative materials - an SEM study.

    PubMed

    Bagheri, R; Burrow, M F; Tyas, M J

    2007-01-01

    To determine the degree of surface roughness of glass-ionomer cements (GICs) and polyacid-modified resin composite (PAMRC) after polishing and immersion in various foodstuffs. Three tooth-coloured restorative materials were used: a PAMRC (F2000), a conventional glass-ionomer cement (CGIC) (Fuji IX) and a resin-modified glass-ionomer cements (RM-GIC) (Fuji II LC). Disk-shaped specimens were prepared and tested with either a plastics matrix finish or after polishing with wet silicon carbide papers up to 2000-grit. All specimens were immersed in 37 degrees C-distilled water for 1 week, followed by three different foodstuffs (red wine, coffee or tea) for a further 2 weeks. Replicas of specimens were prepared by taking polyvinyl siloxane impressions, casting in epoxy resin, gold sputter-coating and examining using a Field-Emission Scanning Electron Microscope. The polished and matrix finish specimens of F2000 showed many microcracks at low magnification, and eroded surfaces with missing and protruding particles at high magnification in the polished specimens. The surface-polished specimens of Fuji II LC were considerably rougher than the matrix-finish specimens, with large voids and protruding filler particles. The effects of foodstuffs on Fuji II LC and F2000 were not noticeable. The CGIC became noticeably rougher after exposure to coffee and tea. All specimens had the smoothest surface when they were cured against a plastics matrix strip, and all materials had a rougher surface after polishing. None of the foodstuffs produced a perceptible increase in roughness on RM-GIC and PAMRC surfaces, whereas coffee and tea markedly increased the surface roughness of Fuji IX. PMID:17207080

  5. Use of temporary filling material for index fabrication in Class IV resin composite restoration.

    PubMed

    Kim, Kun-Young; Kim, Sun-Young; Kim, Duck-Su; Choi, Kyoung-Kyu

    2013-05-01

    When a patient with a fractured anterior tooth visits the clinic, clinician has to restore the tooth esthetically and quickly. For esthetic resin restoration, clinician can use 'Natural Layering technique' and an index for palatal wall may be needed. In this case report, we introduce pre-restoration index technique on a Class IV defect, in which a temporary filling material is used for easy restoration. Chair-side index fabrication for Class IV restoration is convenient and makes a single-visit treatment possible.

  6. Repeated exposure of acidic beverages on esthetic restorative materials: An in-vitro surface microhardness study

    PubMed Central

    Sunny, Steffy M.; Rai, Kavita; Hegde, Amitha M.

    2016-01-01

    Background A manifold increase in the consumption of aerated beverages has witnessed a twin increase in tooth wear and raised demand for esthetic restorative materials. This study aimed to evaluate the surface microhardness changes of esthetic restorative materials following treatment with aerated beverages in an in-vitro situation. Material and Methods The initial surface microhardness of the restorative materials GC Fuji II LC, GC Fuji IX, Nano Glass ionomer, Resin and Nano composite was recorded. These materials were studied under 3 groups that included those exposed to the acidic beverages daily, weekly once in a month and those that had no exposures at all. The final surface microhardness of the materials was recorded following experimentation and was subjected to statistical comparisons. Results The restorative materials were compared for their surface microhardness changes following respective treatments using the T-test and One-way ANOVA analysis. Inter-comparisons between the groups showed statistical significance (p<.05), when treated with both the beverages. The five restorative materials revealed surface microhardness loss; the maximum reduction noticed with the Nano glass ionomer cement tested (p<.0005). Conclusions The surface microhardness of restorative materials markedly reduced upon repeated exposures with acidic beverages; the product with phosphoric acid producing the maximum surface microhardness loss. Key words:Restorative materials, acidic beverages, surface microhardness, resin composites, glass ionomers. PMID:27398183

  7. Effects of elevated temperatures on different restorative materials: An aid to forensic identification processes

    PubMed Central

    Pol, Chetan A.; Ghige, Suvarna K.; Gosavi, Suchitra R.; Hazarey, Vinay K.

    2015-01-01

    Background: Heat-induced alterations to dental and restorative materials can be of great interest to forensic dentistry. Knowing the specific optical behavior of dental materials can be of high importance as recognition of changes induced by high temperatures can lead to the determination of material which was used in a dental restoration, facilitating identification of burned human remains. Aim: To observe the effects of predetermined temperatures (200°C–400°C–600°C–800°C–1000°C) on unrestored teeth and different restorative materials macroscopically and then examine them under a stereomicroscope for the purpose of identification. Materials and Methods: The study was conducted on 375 extracted teeth which were divided into five groups of 75 teeth each as follows: group 1- unrestored teeth, group 2- teeth restored with all-ceramic crowns, Group 3- with class I silver amalgam filling, group 4- with class I composite restoration, and group 5- with class I glass ionomer cement restoration. Results: Unrestored and restored teeth display a series of specific macroscopic & stereomicroscopic structural changes for each range of temperature. Conclusion: Dental tissues and restorative materials undergo a series of changes which correlate well with the various temperatures to which they were exposed. These changes are a consequence of the nature of the materials and their physicochemical characteristics. PMID:26005305

  8. Restorative material and other tooth-specific variables associated with the decision to repair or replace defective restorations: findings from The Dental PBRN

    PubMed Central

    Gordan, Valeria V.; Riley, Joseph L.; Worley, Donald C.; Gilbert, Gregg H.

    2012-01-01

    Objectives Using data from dentists participating in The Dental Practice-Based Research Network (DPBRN), the study had 2 main objectives: (1) to identify and quantify the types of restorative materials in the existing failed restorations; and (2) to identify and quantify the materials used to repair or replace those failed restorations. Methods This cross-sectional study used a consecutive patient/restoration recruitment design. Practitioner-investigators recorded data on consecutive restorations in permanent teeth that needed repair or replacement. Data included the primary reason for repair or replacement, tooth surface(s) involved, restorative materials used, and patient demographics. Results Data for 9,875 restorations were collected from 7,502 patients in 197 practices for which 75% of restorations were replaced and 25% repaired. Most of the restorations that were either repaired or replaced were amalgam (56%) for which most (56%) of the material used was direct tooth-colored. The restorative material was 5 times more likely to be changed when the original restoration was amalgam (OR=5.2, p<.001). The likelihood of changing an amalgam restoration differed as a function of the tooth type (OR=3.0, p<.001), arch (OR=6.6, p<.001); and number of surfaces in the original restoration (OR=12.2, p<.001). Conclusion The probability of changing from amalgam to another restorative material differed with several characteristics of the original restoration. The change was most likely to take place when (1) the treatment was a replacement; (2) the tooth was not a molar; (3) the tooth was in the maxillary arch; and (4) the original restoration involved a single surface. PMID:22342563

  9. Discrimination of tooth layers and dental restorative materials using cutting sounds.

    PubMed

    Zakeri, Vahid; Arzanpour, Siamak; Chehroudi, Babak

    2015-03-01

    Dental restoration begins with removing carries and affected tissues with air-turbine rotary cutting handpieces, and later restoring the lost tissues with appropriate restorative materials to retain the functionality. Most restoration materials eventually fail as they age and need to be replaced. One of the difficulties in replacing failing restorations is discerning the boundary of restorative materials, which causes inadvertent removal of healthy tooth layers. Developing an objective and sensor-based method is a promising approach to monitor dental restorative operations and to prevent excessive tooth losses. This paper has analyzed cutting sounds of an air-turbine handpiece to discriminate between tooth layers and two commonly used restorative materials, amalgam and composite. Support vector machines were employed for classification, and the averaged short-time Fourier transform coefficients were selected as the features. The classifier performance was evaluated from different aspects such as the number of features, feature scaling methods, classification schemes, and utilized kernels. The total classification accuracies were 89% and 92% for cases included composite and amalgam materials, respectively. The obtained results indicated the feasibility and effectiveness of the proposed method.

  10. Two-year evaluation of a new nano-ceramic restorative material.

    PubMed

    Schirrmeister, J F; Huber, K; Hellwig, E; Hahn, P

    2006-09-01

    The purpose of this prospective study was to evaluate the clinical performance of a new restorative material (Ceram.X) in combination with a new primer-adhesive (K-0127). One operator placed two Class I or II restorations in molars of 43 patients. One molar was restored with Ceram.X/K-0127, the other one with Tetric Ceram/Syntac Classic. At baseline, after 1 and 2 years, the restorations were evaluated by one evaluator using modified Ryge's criteria. After 2 years, 31 patients were examined. One Ceram.X-restoration had to be removed for root canal treatment due to pulpitis. Thus, failure rate of Ceram.X was 3.2% and of Tetric Ceram, 0%. In both groups, no sensitivity, no recurrent caries, and no changes in surface texture were recorded after 2 years. One restoration in each group showed slight changes in color stability (score B). Marginal discoloration (score B) was found concerning three Ceram.X-restorations (10.0%) and two Tetric Ceram-restoration (6.5%). Marginal integrity was score B for four Ceram.X-restorations (13.3%) and for four Tetric Ceram-restorations (12.9%). No statistically significant differences were found (p>0.05). After 2 years of clinical service, 96.8% of Ceram.X/K-0127 and 100% of Tetric Ceram/Syntac Classic restorations were in place and performed clinically well.

  11. [Changes in gingival blood circulation in patients with provisional fixed acrylic dentures].

    PubMed

    Shcherbakov, A S; Rudakova, Iu A; Ivanova, S B; Nekrasov, A N

    2015-01-01

    The adhesion of oral microorganisms to the surface of teeth and dental restorative materials is often the starting point in the developments of caries and periodontal disease. Formation of biofilm on the surface provisional acrylic bridge is especially quickly and can potentially generate decay or periodontal disease on the teeth. Occlusion trauma and occlusion disorders effects on increasing of injure regional periodontal tissues. Using ultrasonic doppler diagnostics oral mucosal blood flow was measured in 79 patients with periodontitis of medium severity with different hygiene conditions before and during orthopedic treatment by provisional fixed dentures was model by different methods. According to the results of this study was stated optimization of oral mucosal blood flow after pre-prosthetic treatments and the supportive hygiene periodontal care during the treatment. Results was used for reduce of functional stress in the in periodontal tissues during the orthopedic alignment by the use of fixed dentures. Specific prosthodontic hygiene protocol and model by individual articulator must be used to treat patients with widespread chronic periodontitis by interim prostheses. PMID:25909614

  12. Gold and palladium burden from dental restoration materials.

    PubMed

    Drasch, G; Muss, C; Roider, G

    2000-06-01

    From 81 volunteers (16 without dental restorations, 65 with gold crowns or inlays) samples of saliva before and after chewing gum, blood, serum, urine and faeces were taken and analysed for gold (Au) and palladium (Pd). The Au concentration in all analysed biomonitors correlates significantly to the number of teeth with gold restorations. For Pd the correlations were still significant, but weaker than for Au. Persons with gold restorations show maximal Au and Pd concentrations, 10(2)-10(3) higher than the background burden. The calculated maximal daily Au load in saliva (1.38 mg Au per day) reaches the range of an oral Au therapy for rheumatoid arthritis with 6 mg Auranofin (= 1.74 mg Au per day). During this therapy severe and frequent side effects are reported. In contrast, the Au concentration in serum maximally reached from Au restorations, amounts to only approximately 1/20 of the Au level during arthritis therapy. But even under subtherapeutic doses of 1 mg Auranofin/day severe side effects have been reported (4 out of 56 cases). The mean Au blood concentration from 1 mg Auranofin daily was only 3 times higher than our maximum value. A toxicological classification of the Pd values is difficult, because no toxicological threshold limit has been established, especially for the low-level long-term burden with Pd.

  13. The effect of thermocycling on the bonding of different restorative materials to access opening through porcelain fused to metal restorations

    PubMed Central

    AL-Moaleem, Mohammed M.; Shah, Farhan Khalid; Khan, Nausheen Saied

    2011-01-01

    PURPOSE Porcelain fused to metal (PFM) crowns provide the best treatment option for teeth that have a large or defective restoration. More than 20% of teeth with PFM crowns or bridges require non-surgical root canal treatment (NSRCT). This may be due to the effect of restorative procedures and the possible leakage of bacteria and or their by-products, which leads to the demise of the tooth pulp. Thus, this study was planned to compare the ability of the restorative materials to seal perforated PFM specimens. MATERIALS AND METHODS The study evaluates the ability of amalgam, composite or compomer restorative materials to close perforated PFM specimen's in-vitro. Ninety PFM specimens were constructed using Ni-Cr alloys and feldspathic porcelain, and then they were divided into 3 groups: amalgam (A), composite + Exite adhesive bond (B) and compomer + Syntac adhesive bond (C). All the PFM samples were embedded in an acrylic block to provide complete sealing of the hole from the bottom side. After the aging period, each group was further divided into 3 equal subgroups according to the thermocycling period (one week for 70 cycles, one month for 300 cycles and three months for 900 cycles). Each subgroup was put into containers containing dye (Pelikan INK), one maintained at 5℃ and the other at 55℃, each cycle for 30 sec time. The data obtained was analyzed by SPSS, 2006 using one way ANOVA test and student t-test and significant difference level at (P<.01). RESULTS The depth of dye penetration was measured at the interfaces of PFM and filling materials using Co-ordinate Vernier Microscope. The lowest levels of the dye penetration for the three groups, as well as subgroups were during the first week. The values of dye leakage had significantly increased by time intervals in subgroups A and C. CONCLUSION It was seen that amalgam showed higher leakage than composite while compomer showed the lowest level of leakage. PMID:22259701

  14. Influence of cavity design and restorative material on the fracture resistance of maxillary premolars.

    PubMed

    Cubas, Gloria Beatriz de Azevedo; Camacho, Guilherme Briao; Pereira-Cenci, Tatiana; Nonaka, Tomio; Barbin, Eduardo Luiz

    2010-01-01

    This study sought to evaluate how the type of cavity preparation and indirect restorative material affected the fracture resistance of maxillary premolars. Teeth were divided into seven groups (n = 14) according to the cavity preparation design (inlays, partial onlays with palatal canine coverage, and total onlays with coverage of both canines) and restorative material used. After the teeth were prepared, restorations were manufactured using a ceramic or a composite resin and cemented with a resin-based cement, with the exception of a control group consisting of sound premolars with no preparation. Fracture resistance was assessed using a universal testing machine with a 9 mm steel ball at a speed of 0.5 mm/minute until fracture. ANOVA results showed significant differences between restorative materials and types of preparations (p < 0.05). Cavity design did not affect composite resin restorations, while ceramic restorations with partial and total canine coverage presented the lowest fracture resistance values (p < 0.05). Within the limitations of this study, the authors concluded that indirect composite resin restorations offered better performance than ceramic restorations, regardless of the cavity design.

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

    ERIC Educational Resources Information Center

    RQ, 1993

    1993-01-01

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

  16. Measurement of the fluorescence of restorative dental materials using a 655-nm diode laser

    NASA Astrophysics Data System (ADS)

    Zanin, Fatima A. A.; Souza-Campos, Dilma H.; Zanin, Sissi; Brugnera, Aldo, Jr.; Pecora, Jesus D.; Pinheiro, Antonio L. B.; Harari, Sonia

    2001-04-01

    The aim of this study was to determine the level of fluorescence of seven restorative materials using 655 nm diode laser. The laser fluorescence system has ben used as an auxiliary method for the detection of carious lesions. This new diagnostic method increases information which are important for the choice of treatment by the Dentist. The characteristic of restorative materials and sealers interferes in the values obtained by the apparatus during the detection of secondary carious lesions. The optical properties of each biological tissue or material are related to the interaction with the laser beam. Aware of that, the fluorescence of healthy dentin and enamel is 0-15, the authors determined the fluorescence of seven restorative materials with 10 teeth in each group. The laser reading scale differed according to the materia, ranging from 1 to 22 with several materials, for example the sealer without inorganic filler and the glass ionomer, showing fluorescence values similar to carious enamel which interferes with the readings around the restorations resulting in a false positive. Knowledge of restoration material fluorescence can aid in the detection of secondary carious lesions around the restorations.

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

    PubMed

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

    2012-01-01

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

  18. Clinical challenges and the relevance of materials testing for posterior composite restorations.

    PubMed

    Sarrett, David C

    2005-01-01

    Posterior composite restorations have been in use for approximately 30 years. The early experiences with this treatment indicated there were more clinical challenges and higher failure rates than amalgam restorations. Since the early days of posterior composites, many improvements in materials, techniques, and instruments for placing these restorations have occurred. This paper reviews what is known regarding current clinical challenges with posterior composite restorations and reviews the primary method for collecting clinical performance data. This review categorizes the challenges as those related to the restorative materials, those related to the dentist, and those related to the patient. The clinical relevance of laboratory tests is discussed from the perspective of solving the remaining clinical challenges of current materials and of screening new materials. The clinical problems related to early composite materials are no longer serious clinical challenges. Clinical data indicate that secondary caries and restoration fracture are the most common clinical problems and merit further investigation. The effect of the dentist and patient on performance of posterior composite restorations is unclear and more clinical data from hypothesis-driven clinical trials are needed to understand these factors. Improvements in handling properties to ensure void-free placement and complete cure should be investigated to improve clinical outcomes. There is a general lack of data that correlates clinical performance with laboratory materials testing. A proposed list of materials tests that may predict performance in a variety of clinical factors is presented. Polymerization shrinkage and the problems that have been attributed to this property of composite are reviewed. There is a lack of evidence that indicates polymerization shrinkage is the primary cause of secondary caries. It is recommended that composite materials be developed with antibacterial properties as a way of

  19. Clinical performance of three anterior restorative materials over 10 years.

    PubMed

    Jokstad, A; Mjör, I A; Nilner, K; Kaping, S

    1994-02-01

    The long-term performance of two chemically activated composite resins was compared to that of one silicate cement. Bulk and cavosurface marginal discoloration was evaluated with both an indirect photographic method and the direct US Public Health Service evaluation system. The results confirmed that composite resins had superior performance but higher secondary caries incidence than did silicate cements. The macrofilled composite resins showed better clinical performance than the microfilled restorations, as well as similar incidences of bulk and marginal discoloration. The agreement between the scores obtained with the direct evaluation criteria and those resulting from the indirect evaluation method was relatively poor. The indirect scores were usually the same or poorer than the direct clinical scores. The results indicated that the clinical evaluation may be the least sensitive of the two methods. The discrepancy in the scorings may, on the other hand, signify that the indirect photographic method records reflectance spectra that are not normally obtained in vivo.

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

  1. Informatics systems to assess and apply clinical research on dental restorative materials.

    PubMed

    Anusavice, K J

    2003-12-01

    Dental biomaterials are used clinically for one or more of the following purposes: to restore function, to enhance esthetics, and to prevent or arrest demineralization of tooth structure. Studies of the clinical performance of restorations and prostheses made from these materials have generally focused on quality assessment and survival statistics. Data from these studies should provide probabilities of specific treatment outcomes that are useful for practicing dentists. However, the utility of these data is limited by the lack of national and international standards for assessing these clinical outcomes. Standardized approaches toward clinical informatics and treatment-decision analysis are urgently needed to minimize the variability of clinical outcomes reported in publications associated with direct and indirect restorative materials used for dental restorations and prostheses.

  2. Antibacterial Effect and Physical-Mechanical Properties of Temporary Restorative Material Containing Antibacterial Agents.

    PubMed

    Mushashe, Amanda Mahammad; Gonzaga, Carla Castiglia; Tomazinho, Paulo Henrique; da Cunha, Leonardo Fernandes; Leonardi, Denise Piotto; Pissaia, Janes Francio; Correr, Gisele Maria

    2015-01-01

    Introduction. For the maintenance of the aseptic chain created during the treatment the coronal sealing becomes paramount. Aim. Evaluating the antibacterial effect and the physical-mechanical properties of a temporary restorative material containing different antibacterial agents. Material and Methods. Two antibacterial agents (triclosan and chloramine T) were manually added to a temporary restorative material used as base (Coltosol). The antibacterial action of the material was analyzed using the agar diffusion method, in pure cultures of Escherichia coli (ATCC BAA-2336) and Staphylococcus aureus (ATCC 11632) and mixed culture of saliva collection. The microleakage rate was analyzed using bovine teeth, previously restored with the materials, and submitted to thermocycling, in a solution of 0.5% methylene blue, for a period of 24 hours. The physical and mechanical properties of the materials analyzed were setting time, water sorption, solubility, and compression strength. Results. No marginal leakage was observed for all groups. There was no statistical significant difference in antimicrobial activity, setting time, water sorption, solubility, and compression strength among the materials. Conclusion. The addition of antibacterial agents on a temporary restorative material did not optimize the antibacterial ability of the material and also did not change its physical-mechanical properties.

  3. Proper restorative material selection, digital processes allow highly esthetic shade match combined with layered porcelain.

    PubMed

    Kahng, Luke S

    2014-03-01

    Today's digital technologies are affording dentists and laboratory technicians more control over material choices for creating restorations and fabricating dental prostheses. Digital processes can potentially enable technicians to create ideal marginal areas and account for the thickness and support of layering porcelain over substructures in the design process. In this case report of a restoration of a single central incisor, a number of issues are addressed that are central to using the newest digital technology. As demonstrated, shade selection is a crucial early step in any restorative case preparation.

  4. Microleakage of Ormocer-based restorative material in primary teeth: an in vivo study.

    PubMed

    Al-Harbi, Saad D; Farsi, Najat

    2007-01-01

    This in vivo study aimed to compare, by means of dye penetration, the microleakage values of an Ormocer-based material (Admira) and a commonly-used composite resin (Restorative Z-100) and to assess the differences in the degree of microleakage according to the cavity wall location for both tested materials. No statistically significant differences were found in the degree of microleakage between the 2 materials or the location of cavity walls. Additional preventive measures should be considered to minimize leakage since none of the restorative systems used, eliminated microleakage.

  5. Considerations in the use of polymer and fiber-based indirect restorative materials.

    PubMed

    McLaren, E A; Rifkin, R; Devaud, V

    1999-05-01

    Restorative materials and techniques are constantly refined in order to address the aesthetic expectations of patients. Second-generation laboratory-fabricated composite materials have recently been developed to combine the advantages of porcelain with composite resin. This class of biomaterial can be utilized in a variety of direct and indirect clinical applications than include inlay/onlay restorations, full-coverage crowns, fixed partial dentures, and implant-supported prostheses. This article reviews considerations for the use of these materials from clinical indications through cementation.

  6. [Exploration of basic restorative dental materials teaching in the field of dental technology].

    PubMed

    Jin, Yan-ting

    2012-12-01

    This study was to compare the difference of the existing course materials of basic restorative dental with the past materials, found out the weakness of teaching mode before the reform, and explored the reform in education through teaching content, method and evaluation, in order to improve the teaching quality.

  7. Biofilm formation on dental restorative and implant materials.

    PubMed

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

    2010-07-01

    Biomaterials for the restoration of oral function are prone to biofilm formation, affecting oral health. Oral bacteria adhere to hydrophobic and hydrophilic surfaces, but due to fluctuating shear, little biofilm accumulates on hydrophobic surfaces in vivo. More biofilm accumulates on rough than on smooth surfaces. Oral biofilms mostly consist of multiple bacterial strains, but Candida species are found on acrylic dentures. Biofilms on gold and amalgam in vivo are thick and fully covering, but barely viable. Biofilms on ceramics are thin and highly viable. Biofilms on composites and glass-ionomer cements cause surface deterioration, which enhances biofilm formation again. Residual monomer release from composites influences biofilm growth in vitro, but effects in vivo are less pronounced, probably due to the large volume of saliva into which compounds are released and its continuous refreshment. Similarly, conflicting results have been reported on effects of fluoride release from glass-ionomer cements. Finally, biomaterial-associated infection of implants and devices elsewhere in the body is compared with oral biofilm formation. Biomaterial modifications to discourage biofilm formation on implants and devices are critically discussed for possible applications in dentistry. It is concluded that, for dental applications, antimicrobial coatings killing bacteria upon contact are more promising than antimicrobial-releasing coatings.

  8. Four new provisional serovars of Shigella.

    PubMed

    Gross, R J; Thomas, L V; Cheasty, T; Rowe, B; Lindberg, A A

    1989-05-01

    Four bacterial strains are described that possess the biochemical characteristics of Shigella species but do not belong to any of the established Shigella serovars or to any previously described provisional serovar. One strain fermented mannitol, and it is proposed that this be the type strain for a new provisional serovar of Shigella boydii. The remaining strains did not ferment mannitol and belonged to three different serovars. These strains are proposed as type strains for three new provisional serovars of Shigella dysenteriae. All four strains were invasive in a HEp-2 cell tissue culture test, but only one was invasive in the guinea pig eye test and might therefore be expected to cause dysenterylike illness in humans. It is important that the designation of such strains remain provisional until other reference laboratories have had the opportunity to search for additional isolates and the possible pathogenicity of these strains for humans can be further assessed.

  9. Effect of different tetra pack juices on microhardness of direct tooth colored-restorative materials

    PubMed Central

    Fatima, Nazish; Abidi, Syed Yawar Ali; Qazi, Fazal-Ur-Rehaman; Jat, Shahbaz Ahmed

    2012-01-01

    Purpose To examine the effect of apple and orange juices on the surface hardness of direct tooth-colored restorative materials. Materials and methods The materials included resin-modified glass ionomer cement (Vitremer 3M™ ESPE™ Core buildup restorative) and composite resin (Filtek™ 3M™ ESPE™ Z350). A total of 45 disks of each restorative material were prepared. The disks were divided into groups of 15, which were immersed for 7 days in deionized water (G1/G4, control group), apple juice (G2/G5), or orange juice (G3/G6). The pH of the apple juice was approximately 4.8 and the pH of the orange juice was approximately 4.9. Surface hardness tests were performed before immersion and at various times following immersion. Statistical analysis included two-way ANOVA with repeated measurement and Tukey’s test. Results Exposure to juices significantly reduced the hardness of both materials (p < 0.05), while deionized water did not affect the surface hardness of either material. The ionomer cement experienced a greater reduction than the composite resin (p = 0.000). There was no significant difference in the effect of apple and orange juices. Conclusion Juice box-type fruit juices reduced the hardness of direct tooth-colored restorative materials. Material selection should be considered when planning restorations in patients who have experienced tooth surface loss. In terms of the materials evaluated in this study, the composite material provides greater durability under acidic conditions. PMID:23960552

  10. Influence of fluoride-releasing restorative material on root dentine secondary caries in situ.

    PubMed

    Hara, A T; Turssi, C P; Ando, M; González-Cabezas, C; Zero, D T; Rodrigues, A L; Serra, M C; Cury, J A

    2006-01-01

    The usefulness of fluoride-releasing restorations in secondary caries prevention may be questioned because of the presence of other common sources of fluoride and because of ageing of the restorations. This study tested the hypothesis that glass-ionomer cement restorations, either aged or unaged, do not prevent secondary root caries, when fluoride dentifrice is frequently used. Sixteen volunteers wore palatal appliances in two phases of 14 days, according to a 2 x 2 crossover design. In each phase the appliance was loaded with bovine root dentine slabs restored with either glass-ionomer or resin composite, either aged or unaged. Specimens were exposed to cariogenic challenge 4 times/day and to fluoridated dentifrice 3 times/day. The fluoride content in the biofilm (FB) formed on slabs and the mineral loss (DeltaZ) around the restorations were analysed. No differences were found between restorative materials regarding the FB and the DeltaZ, for either aged (p = 0.792 and p = 0.645, respectively) or unaged (p = 1.00 and p = 0.278, respectively) groups. Under the cariogenic and fluoride dentifrice exposure conditions of this study, the glass-ionomer restoration, either aged or unaged, did not provide additional protection against secondary root caries.

  11. Study on effects of partial ossicular replacement prostheses with different materials on hearing restoration.

    PubMed

    Yao, Wenjuan; Guo, Cuiping; Luo, Xuemei

    2013-02-01

    Numerical simulation method was used in this paper to study the effects of partial ossicular replacement prostheses (PORPs) with different materials on hearing restoration, from the biomechanical point of view. According to the CT scan imagery of the right ear from a normal human body, the CT data was digitalized and imported into PATRAN to establish a three dimension finite element model by self-compiling program, and then a frequency response analysis was made for the model. The calculated results were compared with experiment data to verify the correctness of the numerical model. Based on this, human numerical model of PORPs was established to make dynamic calculation of sound conduction and analyse the effects of PORPs with different materials on hearing restoration. The following conclusions are obtained : From the angle of dynamical behaviors in sound conduction process of human ear, in different frequency bands of the same sound pressure, PORPs with different materials have different effects on hearing restoration. A better sound transmission in low frequencies is obtained by PORPs with hydroxyapatite ceramics, stainless steel. In high frequencies, better sound transmission is gained by PORPs with porous polyethylene. In the 500-3,000 Hz range which is clinicians typically measure and pay attention to, better sound transmission is gained by PORPs with alumina ceramics, hydroxyapatite ceramics, EH composite materials and porous polyethylene. There are three materials which has an obvious potential to provide more hearing restoration than another between 500 and 3,000 Hz. The hearing restoration value of hydroxyapatite ceramics is 7.1 dB larger than that of stainless steel. The hearing restoration value of titanium is 4.9 dB larger than that of stainless steel. Hydroxyapatite ceramics has better effects on sound transmission than titanium and other materials. PMID:23109043

  12. Strength and fatigue of polyacid-modified restorative materials (compomers).

    PubMed

    Boberick, Ken G; McCool, John I; Baran, George R

    2002-06-01

    The purpose of this study was to compare the fatigue behavior of a hybrid composite, four compomers, and two viscous glass ionomers after short- and long-term soaking in distilled water. Bars with dimensions of 30 mm x 2 mm x 2 mm were formed in stainless steel molds, finished with 600 grit SiC, then soaked for either 24 h or one year, and tested in 3-point flexure at stressing rates between 0.001 and 2500 MPa s(-1). Data were plotted as fracture stress vs. stressing rate, and the exponent N in the power law for crack growth rate was computed from the slope of these plots. All compomer and resin composite materials tested exhibited subcritical crack growth (i.e. a reduction in strength with a decrease in stressing rate). Soaking lowered the slope for all materials, that is, increased the crack propagation rate. F2000 exhibited an increase in fracture strength while Hytac and Compoglass exhibited a decrease following long-term soaking in distilled water. Crack-growth exponents obtained from these fatigue data were used to estimate the stresses which would result in a five-year lifetime for these materials.

  13. Fracture resistance of endodontically treated teeth restored with a bulkfill flowable material and a resin composite

    PubMed Central

    Isufi, Almira; Plotino, Gianluca; Grande, Nicola Maria; Ioppolo, Pietro; Testarelli, Luca; Bedini, Rossella; Al-Sudani, Dina; Gambarini, Gianluca

    2016-01-01

    Summary Aim To determine and compare the fracture resistance of endodontically treated teeth restored with a bulk fill flowable material (SDR) and a traditional resin composite. Methods Thirty maxillary and 30 mandibular first molars were selected based on similar dimensions. After cleaning, shaping and filling of the root canals and adhesive procedures, specimens were assigned to 3 subgroups for each tooth type (n=10): Group A: control group, including intact teeth; Group B: access cavities were restored with a traditional resin composite (EsthetX; Dentsply-Italy, Rome, Italy); Group C: access cavities were restored with a bulk fill flowable composite (SDR; Dentsply-Italy), except 1.5 mm layer of the occlusal surface that was restored with the same resin composite as Group B. The specimens were subjected to compressive force in a material static-testing machine until fracture occurred, the maximum fracture load of the specimens was measured (N) and the type of fracture was recorded as favorable or unfavorable. Data were statistically analyzed with one-way analysis of variance (ANOVA) and Bonferroni tests (P<0.05). Results No statistically significant differences were found among groups (P<0.05). Fracture resistance of endodontically treated teeth restored with a traditional resin composite and with a bulk fill flowable composite (SDR) was similar in both maxillary and mandibular molars and showed no significant decrease in fracture resistance compared to intact specimens. Conclusions No significant difference was observed in the mechanical fracture resistance of endodontically treated molars restored with traditional resin composite restorations compared to bulk fill flowable composite restorations. PMID:27486505

  14. Restoration of endodontically treated anterior teeth: an evaluation of coronal microleakage of glass ionomer and composite resin materials.

    PubMed

    Diaz-Arnold, A M; Wilcox, L R

    1990-12-01

    A glass ionomer material was evaluated for coronal microleakage in permanent lingual access restorations of endodontically treated anterior teeth. The material was tested as a restoration, placed over a zinc oxide-eugenol base, and as a base with an acid-etched composite resin veneer and a dentinal bonding agent. Restored teeth were thermocycled, immersed in silver nitrate, developed, and sectioned to assess microleakage. Significant coronal leakage was observed with all materials used.

  15. 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

  16. In vitro electrical impedance spectroscopy of human dentine: the effect of restorative materials.

    PubMed

    Rivas, Berta; Botta, Pablo M; Varela, Purificación; Martín, Benjamín; Fondado, Alfonso; Rivas, Jose

    2008-04-01

    The influence of different restorative materials on in vitro dielectric properties of sound dentine was investigated. The studied samples were three-layer materials consisting of successive disks of dentine and silver amalgam or nanohybrid composite resin. Before being tested, the samples were maintained in physiological solution never more than 48 h from the extraction. Also, sections of intact dentine were similarly prepared for electrical measurements. Complex dielectric permittivity of these specimens was determined in a wide frequency range using the parallel-plate capacitor technique. Very similar dielectric responses of intact dentine and amalgam-dentine material were observed. This is explained on the basis of high dc conductivity exhibited by both samples. In contrast, resin-dentine specimen revealed a much more insulating behavior. A simple theoretical model for heterogeneous systems could be applied to these dental three-layer materials. The dielectric properties of restored dentine are strongly dependent on the kind of restorative material employed in each case. This suggests that electrical data should be used carefully in caries diagnosis on restored teeth.

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

    PubMed

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

    2013-01-01

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

  18. Effects of pulp capping materials on fracture resistance of Class II composite restorations

    PubMed Central

    Kucukyilmaz, Ebru; Yasa, Bilal; Akcay, Merve; Savas, Selcuk; Kavrik, Fevzi

    2015-01-01

    Objective: The aim of this study was to investigate the effect of cavity design and the type of pulp capping materials on the fracture resistance of Class II composite restorations. Materials and Methods: Sixty freshly extracted, sound molar teeth were selected for the study. A dovetail cavity on the mesio-occlusal and a slot cavity on disto-occlusal surfaces of each tooth were prepared, and the teeth were divided 4 groups which one of them as a control group. The pulp capping materials (TheraCal LC, Calcimol LC, Dycal) applied on pulpo-axial wall of each cavity, and the restoration was completed with composite resin. The teeth were subjected to a compressive load in a universal mechanical testing machine. The surfaces of the tooth and restoration were examined under a stereomicroscope. The data were analyzed using factorial analysis of variance and Tukey's test. Results: For pulp capping materials, the highest fracture load (931.15 ± 203.81 N) and the lowest fracture load (832.28 ± 245.75 N) were calculated for Control and Dycal group, respectively. However, there were no statistically significant differences among all groups (P > 0.05). The fracture load of the dovetail groups was significantly higher than those of the slot cavity groups (P < 0.05). Conclusion: Dovetail cavity design shows better fracture resistance in Class II composite restorations, independent of used or not used pulp capping materials. PMID:26038653

  19. Effect of Soft Drinks and Fresh Fruit Juice on Surface Roughness of Commonly used Restorative Materials.

    PubMed

    Maganur, Prabhadevi; Satish, V; Prabhakar, A R; Namineni, Srinivas

    2015-01-01

    In this in vitro study, the effects of a Cola drink, and fresh fruit juice (citrus) on the surface roughness on flowable composite and resin-modified glass ionomer cement (RMGIC) each was evaluated and compared. Using a brass mold 70 pellets each of flowable composite (Filtek™ Flow) and RMGIC tricure restorative material were prepared according to the manufacturer's instructions. Two groups (groups I and II) were formed containing 30 pellets of each material. Remaining 10 pellets of each restorative material did form the control group [water (group III)]. Experimental group pellets were again divided into three subgroups (mild, moderate and severe) containing 10 pellets each and were kept in plastic containers with 30 ml Cola drink (group I) and fresh fruit juice (group II) respectively. Immersion regime was followed according to M aupome G et al. Baseline and final surface roughness (Ra) value for each pellet was evaluated using a profilometer. Statistical analysis was done with Wilcoxon's signed rank test and analysis of variance (ANOVA) followed by Mann-Whitney test. Results showed that the erosive effect of both Cola drink and fresh fruit juice caused significant surface roughness on both flowable composite and RMGIC restorative materials in the mild, moderate and severe immersion regimes. How to cite this article: Maganur P, Satish V, Prabhakar AR, Namineni S. Effect of Soft Drinks and Fresh Fruit Juice on Surface Roughness of Commonly used Restorative Materials. Int J Clin Pediatr Dent 2015;8(1):1-5. PMID:26124573

  20. Cerec anterior crowns: restorative options with monolithic ceramic materials.

    PubMed

    Reich, Sven; Fiedlar, Kurt

    2013-01-01

    The aim of this article is to discuss the different types of monolithic ceramic crowns that can be placed on anterior teeth with existing shoulder preparations. Anterior crowns were indicated for the teeth 12 to 22 in the present case. The patient, a 65-year-old male, had received all-ceramic crowns 20 years earlier, which had started to develop cracks and palatal fractures over the last few years. The patient's teeth were prepared and four sets of crowns were fabricated using different monolithic ceramic materials: IPS e.max CAD, Cerec Blocs C In, VITABLOCS Real Life, and ENAMIC. Both shade characterization and crystallization firing were performed on the monolithic lithium disilicate glass ceramic crowns. The silicate ceramic crowns received glaze firing alone. The crowns made of hybrid ceramic (ENAMIC) were treated with a polymer sealant. PMID:24555406

  1. Colour stability of tooth-coloured restorative materials.

    PubMed

    Gaintantzopoulou, Marianna; Kakaboura, Afrodite; Vougiouklakis, Georgios

    2005-06-01

    The colour stability of the surface and in-depth (2 mm) layer of two resin composites, a laboratory second-generation resin composite and a compomer were evaluated after 24 and 360 hours of water aging under dark and UV light conditions. The influence of various polymerization techniques on color changes was also evaluated. Color differences (deltaE*) showed higher color changes under UV light exposure than under dark storage, both at 24- and 360-hour evaluations. Color changes were statistically higher at the 360-hour assessment, in both conditions of maintenance. Compomer was the least color stable of the materials tested. Additional polymerization significantly decreased the colour change of both composite resins.

  2. Cariostatic effect of fluoride-containing restorative materials associated with fluoride gels on root dentin

    PubMed Central

    BORGES, Fernanda Tavares; CAMPOS, Wagner Reis da Costa; MUNARI, Lais Sant'ana; MOREIRA, Allyson Nogueira; PAIVA, Saul Martins; MAGALHÃES, Claudia Silami

    2010-01-01

    Secondary caries is still the main cause of restoration replacement, especially on the root surface Objective This in vitro study evaluated the cariostatic effects of fluoride-containing restorative materials associated with fluoride gels, on root dentin. Materials and Methods A randomized complete block design was used to test the effects of the restorative systems, fluoride regimes and the interactions among them at different distances from restoration margins. Standardized cavities were prepared on 240 bovine root specimens and randomly assigned to 15 groups of treatments (n=16). Cavities were filled with the following restorative materials: Ketac-Fil (3M-ESPE); Vitremer (3M-ESPE); Dyract/Prime & Bond NT (Dentsply); Charisma/Gluma One Bond (Heraeus Kulzer) and the control, Z250/Single Bond (3M-ESPE). The specimens were subjected to a pH-cycling model designed to simulate highcaries activity. During the cycles, 1.23% acidulated phosphate fluoride, 2.0% neutral sodium fluoride or deionized/distilled water (control) was applied to the specimens for 4 min. The surface Knoop microhardness test was performed before (KHNi) and after (KHNf) the pH cycles at 100, 200 and 300 mm from the margins. Dentin microhardness loss was represented by the difference in initial and final values (KHNi - KHNf). Data were analyzed by Friedman's and Wilcoxon's tests, ANOVA and Tukey's test (α=5%). Results The interaction of restorative systems and topical treatments was not significant (p=0.102). Dentin microhardness loss was lowest closer to the restoration. Ketac-fil presented the highest cariostatic effect. Vitremer presented a moderate effect, while Dyract and Charisma did not differ from the control, Z250. The effects of neutral and acidulated fluoride gels were similar to each other and higher than the control. Conclusion Conventional and resin-modified glass ionomer cements as well as neutral and acidulated fluoride gels inhibit the progression of artificial caries adjacent to

  3. Investigation of the electrical properties of some dental composite restorative materials before and after laser exposure.

    PubMed

    ElKestawy, M A; Saafan, S A; Shehata, M M; Saafan, A M

    2006-10-01

    Some electrical properties, such as piezoelectricity, ac conductivity, dielectric constant and loss tangent of nine commercial types of dental composite restorative materials, have been investigated before and after laser exposure for 3s to study the effect of a probable laser exposure during some surgeries on the electrical properties of these materials. No piezoelectric effect has been found in these materials before and after laser exposure. The materials were found to be good insulators (very poorly conducting materials). The temperature and frequency dependence of ac conductivity, dielectric constant and loss tangent have not shown significant changes in values after laser exposure.

  4. Retention of long-term interim restorations with sodium fluoride enriched interim cement

    NASA Astrophysics Data System (ADS)

    Strash, Carolyn

    Purpose: Interim fixed dental prostheses, or "provisional restorations", are fabricated to restore teeth when definitive prostheses are made indirectly. Patients undergoing extensive prosthodontic treatment frequently require provisionalization for several months or years. The ideal interim cement would retain the restoration for as long as needed and still allow for ease of removal. It would also avoid recurrent caries by preventing demineralization of tooth structure. This study aims to determine if adding sodium fluoride varnish to interim cement may assist in the retention of interim restorations. Materials and methods: stainless steel dies representing a crown preparation were fabricated. Provisional crowns were milled for the dies using CAD/CAM technology. Crowns were provisionally cemented onto the dies using TempBond NE and NexTemp provisional cements as well as a mixture of TempBond NE and Duraphat fluoride varnish. Samples were stored for 24h then tested or thermocycled for 2500 or 5000 cycles before being tested. Retentive strength of each cement was recorded using a universal testing machine. Results: TempBond NE and NexTemp cements performed similarly when tested after 24h. The addition of Duraphat significantly decreased the retention when added to TempBond NE. NexTemp cement had high variability in retention over all tested time periods. Thermocycling for 2500 and 5000 cycles significantly decreased the retention of all cements. Conclusions: The addition of Duraphat fluoride varnish significantly decreased the retention of TempBond NE and is therefore not recommended for clinical use. Thermocycling significantly reduced the retention of TempBond NE and NexTemp. This may suggest that use of these cements for three months, as simulated in this study, is not recommended.

  5. Materials and techniques for achieving clinical excellence with indirect composite restorations.

    PubMed

    Brucia, J J

    2001-01-01

    Indirect resin restoration technology continues to grow at an unbelievable rate. This article has outlined some of the materials available within this category. There are others that the author has not had the opportunity to work with. At this time, the author believes the primary indication for the use of this class of material is esthetic inlays and onlays as well as a well-planned conservative [figure: see text] fixed partial denture in a low stress area. If unclear about the best material to use in a given situation, the dentist should consult the laboratory technician to discuss the technician's experience and confidence with the different systems. Many times the physical properties of the material are not as important as the ability of the technician and his or her experience with the different handling properties of the available systems when examining the short-term and long-term success of the restoration.

  6. RESTORING A DAMAGED 16-YEAR -OLD INSULATING POLYMER CONCRETE DIKE OVERLAY: REPAIR MATERIALS AND TECHNOLOGIES.

    SciTech Connect

    SUGAMA,T.

    2007-01-01

    The objective of this program was to design and formulate organic polymer-based material systems suitable for repairing and restoring the overlay panels of insulating lightweight polymer concrete (ILPC) from the concrete floor and slope wall of a dike at KeySpan liquefied natural gas (LNG) facility in Greenpoint, Brooklyn, NY, just over sixteen years ago. It also included undertaking a small-scale field demonstration to ensure that the commercial repairing technologies were applicable to the designed and formulated materials.

  7. Restoration materials and secondary caries using an in vitro biofilm model.

    PubMed

    Kuper, N K; van de Sande, F H; Opdam, N J M; Bronkhorst, E M; de Soet, J J; Cenci, M S; Huysmans, M C D J N M

    2015-01-01

    This in vitro study investigated whether restoration materials and adhesives influence secondary caries formation in gaps using a short-term in vitro biofilm model. Sixty enamel-dentin blocks were restored with 6 different restoration materials with or without adhesives (n = 10 per group) with a gap: 1) Clearfil AP-X composite, 2) Clearfil AP-X composite + SE Bond, 3) Clearfil AP-X composite + ProtectBond, 4) Filtek Silorane composite, 5) Filtek Silorane composite + Silorane System adhesive, or 6) Tytin amalgam. Specimens were subjected to an intermittent 1% sucrose biofilm model for 20 days to create artificial caries lesions. Lesion progression in the enamel-dentin next to the different materials was measured in lesion depth (LD) and mineral loss (ML) using transversal wavelength independent microradiography (T-WIM). A regression analysis was used to compare the LD and ML of the different restoration materials at 4 measurement locations: 1 location at the surface of the enamel, 1 location at the wall of the enamel, and 2 locations at the wall of the dentin. A statistically significant effect of AP-X composite with Protect Bond was found for LD and ML at the WallDentin1 location, leading to less advanced wall lesions. An additional finding was that gap size was also statistically significant at the 2 wall locations in dentin, leading to increasing lesion progression with wider gaps. In conclusion, adhesives can influence wall lesion development in gaps. Protect Bond showed significantly less caries progression compared to bare restoration materials or other adhesives in this short-term in vitro biofilm model. PMID:25297114

  8. Restoration materials and secondary caries using an in vitro biofilm model.

    PubMed

    Kuper, N K; van de Sande, F H; Opdam, N J M; Bronkhorst, E M; de Soet, J J; Cenci, M S; Huysmans, M C D J N M

    2015-01-01

    This in vitro study investigated whether restoration materials and adhesives influence secondary caries formation in gaps using a short-term in vitro biofilm model. Sixty enamel-dentin blocks were restored with 6 different restoration materials with or without adhesives (n = 10 per group) with a gap: 1) Clearfil AP-X composite, 2) Clearfil AP-X composite + SE Bond, 3) Clearfil AP-X composite + ProtectBond, 4) Filtek Silorane composite, 5) Filtek Silorane composite + Silorane System adhesive, or 6) Tytin amalgam. Specimens were subjected to an intermittent 1% sucrose biofilm model for 20 days to create artificial caries lesions. Lesion progression in the enamel-dentin next to the different materials was measured in lesion depth (LD) and mineral loss (ML) using transversal wavelength independent microradiography (T-WIM). A regression analysis was used to compare the LD and ML of the different restoration materials at 4 measurement locations: 1 location at the surface of the enamel, 1 location at the wall of the enamel, and 2 locations at the wall of the dentin. A statistically significant effect of AP-X composite with Protect Bond was found for LD and ML at the WallDentin1 location, leading to less advanced wall lesions. An additional finding was that gap size was also statistically significant at the 2 wall locations in dentin, leading to increasing lesion progression with wider gaps. In conclusion, adhesives can influence wall lesion development in gaps. Protect Bond showed significantly less caries progression compared to bare restoration materials or other adhesives in this short-term in vitro biofilm model.

  9. Restoration Materials and Secondary Caries Using an In Vitro Biofilm Model

    PubMed Central

    van de Sande, F.H.; Opdam, N.J.M.; Bronkhorst, E.M.; de Soet, J.J.; Cenci, M.S.; Huysmans, M.C.D.J.N.M.

    2015-01-01

    This in vitro study investigated whether restoration materials and adhesives influence secondary caries formation in gaps using a short-term in vitro biofilm model. Sixty enamel–dentin blocks were restored with 6 different restoration materials with or without adhesives (n = 10 per group) with a gap: 1) Clearfil AP-X composite, 2) Clearfil AP-X composite + SE Bond, 3) Clearfil AP-X composite + ProtectBond, 4) Filtek Silorane composite, 5) Filtek Silorane composite + Silorane System adhesive, or 6) Tytin amalgam. Specimens were subjected to an intermittent 1% sucrose biofilm model for 20 days to create artificial caries lesions. Lesion progression in the enamel–dentin next to the different materials was measured in lesion depth (LD) and mineral loss (ML) using transversal wavelength independent microradiography (T-WIM). A regression analysis was used to compare the LD and ML of the different restoration materials at 4 measurement locations: 1 location at the surface of the enamel, 1 location at the wall of the enamel, and 2 locations at the wall of the dentin. A statistically significant effect of AP-X composite with Protect Bond was found for LD and ML at the WallDentin1 location, leading to less advanced wall lesions. An additional finding was that gap size was also statistically significant at the 2 wall locations in dentin, leading to increasing lesion progression with wider gaps. In conclusion, adhesives can influence wall lesion development in gaps. Protect Bond showed significantly less caries progression compared to bare restoration materials or other adhesives in this short-term in vitro biofilm model. PMID:25297114

  10. Effect of material properties of composite restoration on the strength of the restoration-dentine interface due to polymerization shrinkage, thermal and occlusal loading.

    PubMed

    Borkowski, Krzysztof; Kotousov, Andrei; Kahler, Bill

    2007-07-01

    The purpose of this investigation was to adopt an analytical approach to analyse stresses at the restoration-dentine interface caused by polymerization shrinkage, occlusal and thermal loading with the primary focus on evaluating the effect of the material properties of the composite restoration on the strength of the interface. Some essential simplifications were employed to derive an explicit analytical solution. The results confirm previous findings that interfacial stresses due to polymerization shrinkage are increased with the higher modulus of elasticity of the restoration, while Poisson's ratio of the restorative material has a very small influence on these stresses. Occlusal loading resulted in much lower interfacial stresses when compared to shrinkage and thermal loads. The obtained results were in a good agreement with other numerical and clinical studies. From the modelling analysis it was found that the majority of commercially available composite restorative materials are expected to create significant interfacial stresses when subjected to cold temperatures. In addition, it was shown that there is a considerable potential for interfacial stresses to be minimised by an appropriate selection of thermo-mechanical properties of the restorative material especially with the new finding on the negative temperature variation effect. PMID:17000129

  11. Calculation of the shrinkage-induced residual stress in a viscoelastic dental restorative material

    NASA Astrophysics Data System (ADS)

    Grassia, Luigi; D'Amore, Alberto

    2013-02-01

    A procedure able to describe the curing process of a particulate composite material used in a dental restoration is developed in the ANSYS environment. The material under concern is a multifunctional methacrylate-based composite for dental restoration, activated by visible light. The model accounts for the dependence of the viscoelastic functions on temperature and degree of cure. Three geometries have been considered in the analysis that are representative of three different classes of dental restoration and mainly differ by the C (constrained)-factor, (i.e. the bounded to unbounded surface ratio). It was found that the temperature could give a necrosis in the vicinity of the tooth nerve and that the average stress at the interface between the composite and the tooth scales exponentially with the C-factor. The residual stress at the dental restoration interface is also compared with the uniaxial tensile strength of twelve commercially available composite materials: it clearly appears that the level of residual stress may overcome the strength of the composite, especially at high C-factors.

  12. Evaluation of the Flexural Strength of Interim Restorative Materials in Fixed Prosthodontics

    PubMed Central

    Mehrpour, Hanieh; Farjood, Ehsan; Giti, Rashin; Barfi Ghasrdashti, Alireza; Heidari, Hossein

    2016-01-01

    Statement of the Problem Mechanical properties of interim restorations are considered as important factors specially when selecting materials for long-term application or for patients with para-functional habits. Flexural strength is one of the most important components of these restorations. Purpose The purpose of this study was to compare the flexural strength of five interim restorative materials. Materials and Method Fifty identical samples sized 25×2×2-mm were made from five interim materials (TempSpan; Protemp 4, Unifast III, Trim, and Revotek LC) according to ADA specification #27. The specimens were stored in artificial saliva for 2 weeks and then thermocycled for 2500 cycles (5-55˚C). A standard three-point bending test was conducted on the specimens with a universal testing machine at a crosshead speed of 0.75mm/min. Data were analyzed by using one-way ANOVA and Tamhane’s post-hoc tests to measure the flexural strength of temporary materials. Results One of the bis-acryl resins (TempSpan) showed the highest, and the light polymerized resin (Revotek LC) showed the lowest flexural strength. The mean values of flexural strength (MPa) for the examined materials were as follow: TempSpan=120.00, Protemp 4=113.00, Unifast III=64.20, Trim= 63.73 and Revotek LC=47.16. There were significant differences between all materials except Trim and Unifast III which did not show any statistical significant difference. Conclusion Bis-acryl resins were statistically superior to traditional methacrylate and light-cured resins. Therefore, application of bis-acryl resins should be deliberated in patients with heavy occlusion and in cases that need long-term use of interim restorations. PMID:27602395

  13. Evaluation of the Flexural Strength of Interim Restorative Materials in Fixed Prosthodontics

    PubMed Central

    Mehrpour, Hanieh; Farjood, Ehsan; Giti, Rashin; Barfi Ghasrdashti, Alireza; Heidari, Hossein

    2016-01-01

    Statement of the Problem Mechanical properties of interim restorations are considered as important factors specially when selecting materials for long-term application or for patients with para-functional habits. Flexural strength is one of the most important components of these restorations. Purpose The purpose of this study was to compare the flexural strength of five interim restorative materials. Materials and Method Fifty identical samples sized 25×2×2-mm were made from five interim materials (TempSpan; Protemp 4, Unifast III, Trim, and Revotek LC) according to ADA specification #27. The specimens were stored in artificial saliva for 2 weeks and then thermocycled for 2500 cycles (5-55˚C). A standard three-point bending test was conducted on the specimens with a universal testing machine at a crosshead speed of 0.75mm/min. Data were analyzed by using one-way ANOVA and Tamhane’s post-hoc tests to measure the flexural strength of temporary materials. Results One of the bis-acryl resins (TempSpan) showed the highest, and the light polymerized resin (Revotek LC) showed the lowest flexural strength. The mean values of flexural strength (MPa) for the examined materials were as follow: TempSpan=120.00, Protemp 4=113.00, Unifast III=64.20, Trim= 63.73 and Revotek LC=47.16. There were significant differences between all materials except Trim and Unifast III which did not show any statistical significant difference. Conclusion Bis-acryl resins were statistically superior to traditional methacrylate and light-cured resins. Therefore, application of bis-acryl resins should be deliberated in patients with heavy occlusion and in cases that need long-term use of interim restorations.

  14. Priorities for future innovation, research, and advocacy in dental restorative materials.

    PubMed

    Watson, T; Fox, C H; Rekow, E D

    2013-11-01

    Innovations in materials science, both within and outside of dentistry, open opportunities for the development of exciting direct restorative materials. From rich dialog among experts from dental and non-dental academic institutions and industry, as well as those from policy, research funding, and professional organizations, we learned that capitalizing on these opportunities is multifactorial and far from straightforward. Beginning from the point when a restoration is needed, what materials, delivery systems, and skills are needed to best serve the most people throughout the world's widely varied economic and infrastructure systems? New research is a critical element in progress. Effective advocacy can influence funding and drives change in practice and policy. Here we articulate both research and advocacy priorities, with the intention of focusing the energy and expertise of our best scientists on making a difference, bringing new innovations to improve oral health. PMID:24129817

  15. Translucency of human teeth and dental restorative materials and its clinical relevance

    NASA Astrophysics Data System (ADS)

    Lee, Yong-Keun

    2015-04-01

    The purpose was to review the translucency of human teeth and related dental materials that should be considered for the development of esthetic restorative materials. Translucency is the relative amount of light transmission or diffuse reflection from a substrate surface through a turbid medium. Translucency influences the masking ability, color blending effect, and the degree of light curing through these materials. Regarding the translucency indices, transmission coefficient, translucency parameter, and contrast ratio have been used, and correlations among these indices were confirmed. Translucency of human enamel and dentine increases in direct proportion to the wavelength of incident light in the visible light range. As for the translucency changes by aging, limited differences were reported in human dentine, while those for enamel proved to increase. There have been studies for the adjustment of translucency in dental esthetic restorative materials; the size and amount of filler and the kind of resin matrix were modified in resin composites, and the kind of ingredient and the degree of crystallization were modified in ceramics. Based on the translucency properties of human enamel and dentine, those of replacing restorative materials should be optimized for successful esthetic rehabilitation. Biomimetic simulation of the natural tooth microstructure might be a promising method.

  16. Translucency of human teeth and dental restorative materials and its clinical relevance.

    PubMed

    Lee, Yong-Keun

    2015-04-01

    The purpose was to review the translucency of human teeth and related dental materials that should be considered for the development of esthetic restorative materials. Translucency is the relative amount of light transmission or diffuse reflection from a substrate surface through a turbid medium. Translucency influences the masking ability, color blending effect, and the degree of light curing through these materials. Regarding the translucency indices, transmission coefficient, translucency parameter, and contrast ratio have been used, and correlations among these indices were confirmed. Translucency of human enamel and dentine increases in direct proportion to the wavelength of incident light in the visible light range. As for the translucency changes by aging, limited differences were reported in human dentine, while those for enamel proved to increase. There have been studies for the adjustment of translucency in dental esthetic restorative materials; the size and amount of filler and the kind of resin matrix were modified in resin composites, and the kind of ingredient and the degree of crystallization were modified in ceramics. Based on the translucency properties of human enamel and dentine, those of replacing restorative materials should be optimized for successful esthetic rehabilitation. Biomimetic simulation of the natural tooth microstructure might be a promising method.

  17. A new, hybrid material for minimally invasive restorations in clinical use.

    PubMed

    Kurbad, A; Kurbad, S

    2013-01-01

    A new type of material consisting of a ceramic substructure infiltrated with a composite material--referred to as a hybrid ceramic--is currently being introduced for dental CAD/CAM use. The characteristic brittleness of ceramic is thus replaced by an elasticity resembling that of natural human dentin. The material features a high fracture load value of 2980 N, and is straightforward to process in CAD/CAM milling machines. This article presents a case example describing the manufacture of a veneer restoration.

  18. Increasing Immunization Compliance by Reducing Provisional Admittance.

    PubMed

    Davis, Wendy S; Varni, Susan E; Barry, Sara E; Frankowski, Barbara L; Harder, Valerie S

    2016-08-01

    Students in Vermont with incomplete or undocumented immunization status are provisionally admitted to schools and historically had a calendar year to resolve their immunization status. The process of resolving these students' immunization status was challenging for school nurses. We conducted a school-based quality improvement effort to increase student compliance with Vermont immunization regulations using a collaborative learning approach with public health school liaisons and school nurses from public schools to reduce provisional admittance in 2011-2012. Strategies included using a tracking system, accessing the immunization registry, promoting immunization importance, tracking immunization plans, and working with medical homes to update records. Participating school nurses observed decreases in the number of provisionally admitted students, although this reduction was not significantly different than matched comparison schools. We also found the number of provisionally admitted students fluctuated throughout the year and resolving the immunization status of New Americans and exchange students required special attention. Our approach supports the coordinated school health model and demonstrates the critical role school nurses play in improving population health outcomes. PMID:26699951

  19. Increasing Immunization Compliance by Reducing Provisional Admittance.

    PubMed

    Davis, Wendy S; Varni, Susan E; Barry, Sara E; Frankowski, Barbara L; Harder, Valerie S

    2016-08-01

    Students in Vermont with incomplete or undocumented immunization status are provisionally admitted to schools and historically had a calendar year to resolve their immunization status. The process of resolving these students' immunization status was challenging for school nurses. We conducted a school-based quality improvement effort to increase student compliance with Vermont immunization regulations using a collaborative learning approach with public health school liaisons and school nurses from public schools to reduce provisional admittance in 2011-2012. Strategies included using a tracking system, accessing the immunization registry, promoting immunization importance, tracking immunization plans, and working with medical homes to update records. Participating school nurses observed decreases in the number of provisionally admitted students, although this reduction was not significantly different than matched comparison schools. We also found the number of provisionally admitted students fluctuated throughout the year and resolving the immunization status of New Americans and exchange students required special attention. Our approach supports the coordinated school health model and demonstrates the critical role school nurses play in improving population health outcomes.

  20. Increasing Immunization Compliance by Reducing Provisional Admittance

    ERIC Educational Resources Information Center

    Davis, Wendy S.; Varni, Susan E.; Barry, Sara E.; Frankowski, Barbara L.; Harder, Valerie S.

    2016-01-01

    Students in Vermont with incomplete or undocumented immunization status are provisionally admitted to schools and historically had a calendar year to resolve their immunization status. The process of resolving these students' immunization status was challenging for school nurses. We conducted a school-based quality improvement effort to increase…

  1. Fracture resistance of endodontically treated teeth restored with ceramic inlays and different base materials.

    PubMed

    Saridag, Serkan; Sari, Tugrul; Ozyesil, Atilla Gokhan; Ari Aydinbelge, Hale

    2015-01-01

    This study evaluated the fracture resistance of endodontically treated teeth restored with different base materials and mesioocclusal-distal (MOD) ceramic inlays. Fifty mandibular molars were assigned into five groups (n=10 per group). Group1 (control) comprised intact molar teeth without any treatment. Teeth in other groups were subjected to root canal treatment and restored with MOD ceramic inlays on different base materials. In Group 2, base material was zinc phosphate cement; Group 3's was glass ionomer cement; Group 4's was composite resin, and Group 5's was composite resin reinforced with fiber. Finally, a continuous occlusal load was applied until fracture occurred. Mean fracture resistance of Group 1 (3,027 N) was significantly higher than the other groups (890, 1,070, 1,670, 1,226 N respectively). Fracture resistance of Group 4 was statistically comparable with Group 5 and significantly higher than Groups 2 and 3 (p<0.05; Tukey's HSD). Use of different base materials under ceramic inlay restorations could affect the fracture resistance of endodontically treated teeth. PMID:25740162

  2. Cytogenetic genotoxic investigation in peripheral blood lymphocytes of subjects with dental composite restorative filling materials.

    PubMed

    Pettini, F; Savino, M; Corsalini, M; Cantore, S; Ballini, A

    2015-01-01

    Dental composite resins are biomaterials commonly used to aesthetically restore the structure and function of teeth impaired by caries, erosion, or fracture. Residual monomers released from resin restorations as a result of incomplete polymerization processes interact with living oral tissues. The objective of this study was to evaluate the genotoxicity of a common dental composite material (Enamel Plus-HFO), in subjects with average 13 filled teeth with the same material, compared to a control group (subjects having neither amalgam nor composite resin fillings). Genotoxicity assessment of composite materials was carried out in vitro in human peripheral blood leukocytes using sister-chromatid exchange (SCE) and chromosomal aberrations (CA) cytogenetic tests. The results of correlation and multiple regression analyses confirmed the absence of a relationship between SCE/cell, high frequency of SCE(HFC) or CA frequencies and exposure to dental composite materials. These results indicate that composite resins used for dental restorations differ extensively in vivo in their cytotoxic and genotoxic potential and in their ability to affect chromosomal integrity, cell-cycle progression, DNA replication and repair. PMID:25864763

  3. Cytogenetic genotoxic investigation in peripheral blood lymphocytes of subjects with dental composite restorative filling materials.

    PubMed

    Pettini, F; Savino, M; Corsalini, M; Cantore, S; Ballini, A

    2015-01-01

    Dental composite resins are biomaterials commonly used to aesthetically restore the structure and function of teeth impaired by caries, erosion, or fracture. Residual monomers released from resin restorations as a result of incomplete polymerization processes interact with living oral tissues. The objective of this study was to evaluate the genotoxicity of a common dental composite material (Enamel Plus-HFO), in subjects with average 13 filled teeth with the same material, compared to a control group (subjects having neither amalgam nor composite resin fillings). Genotoxicity assessment of composite materials was carried out in vitro in human peripheral blood leukocytes using sister-chromatid exchange (SCE) and chromosomal aberrations (CA) cytogenetic tests. The results of correlation and multiple regression analyses confirmed the absence of a relationship between SCE/cell, high frequency of SCE(HFC) or CA frequencies and exposure to dental composite materials. These results indicate that composite resins used for dental restorations differ extensively in vivo in their cytotoxic and genotoxic potential and in their ability to affect chromosomal integrity, cell-cycle progression, DNA replication and repair.

  4. 14 CFR 121.207 - Provisionally certificated airplanes: Operating limitations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Provisionally certificated airplanes... AND OPERATIONS OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Airplane Performance Operating Limitations § 121.207 Provisionally certificated airplanes: Operating limitations....

  5. 14 CFR 121.207 - Provisionally certificated airplanes: Operating limitations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Provisionally certificated airplanes... AND OPERATIONS OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Airplane Performance Operating Limitations § 121.207 Provisionally certificated airplanes: Operating limitations....

  6. 14 CFR 121.207 - Provisionally certificated airplanes: Operating limitations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Provisionally certificated airplanes... AND OPERATIONS OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Airplane Performance Operating Limitations § 121.207 Provisionally certificated airplanes: Operating limitations....

  7. 14 CFR 121.207 - Provisionally certificated airplanes: Operating limitations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Provisionally certificated airplanes... AND OPERATIONS OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Airplane Performance Operating Limitations § 121.207 Provisionally certificated airplanes: Operating limitations....

  8. A study of the fracture resistance of nyyar cores of three restorative materials.

    PubMed

    Ferrier, Stephen; Sekhon, Balraj S; Brunton, Paul A

    2008-01-01

    Despite the successful use of dental amalgam for coronal-radicular dowel and core build-up in endodontically-treated posterior teeth, newer materials offer many potential advantages over amalgam and have better patient acceptance. This study compared the fracture resistance of coronal-radicular restorations made from three different direct restorative materials. Sixty human premolars were selected, 45 of which were root treated and decoronated. Fifteen of these premolars were restored using amalgam, 15 with composite and 15 using resin-modified glass ionomer. The 15 unrestored teeth were used as a control group. All the teeth were mounted in acrylic within steel containers and subjected to compressive loading to failure on a universal testing machine. The force required to fracture each core specimen was recorded as well as the proportion of core lost due to failure. The results showed dental amalgam as having the highest fracture resistance (mean 1.93kN, sd 0.22) followed by resin-modified glass ionomer (mean 1.05kN, sd 0.20), sound tooth (mean 0.79kN, sd 0.20) and composite (mean 0.75kN, sd 0.11). The differences among all groups were significant. These results demonstrate that, although resin-modified glass ionomer is significantly weaker than amalgam, these restorations were stronger than unrestored teeth and failed at forces in excess of those encountered in normal mastication. Amalgam cores, along with resin-modified glass ionomer, tended to fail less catastrophically than the other materials and, given their strength, would remain the material of choice in situations where abnormally high forces are expected.

  9. Chemical or microbiological models of secondary caries development around different dental restorative materials.

    PubMed

    Lobo, Maristela M; Gonçalves, Reginaldo B; Ambrosano, Gláucia Maria B; Pimenta, Luiz André F

    2005-08-01

    This study evaluated artificial secondary caries around restorative materials, induced by means of chemical or microbiological models. The following materials were used randomly to restore 130 dental blocks: (1) zinc-oxide eugenol-free temporary filling: Coltosol (Coltène/Whaledent Inc.; n = 30), (2) silver amalgam: Permite C (SDI Limited, n = 20), (3) composite resin: Filtek Z250 (3M ESPE; n = 20), (4) glass-ionomer cement: Fuji II (GC America Inc.; n = 20), (5) resin-modified glass ionomer: Vitremer (3M ESPE; n = 20), and (6) polyacid modified resin: Dyract AP (Dentsply; n = 20). Ten specimens of Group 1 were kept in humidity, and had no carious formation (NC). Ten specimens of each group were submitted to pH cycling (CG, n = 60), and the others were immersed in a medium containing Streptococcus mutans and sucrose (BG, n = 60). Mineral content was determined by microhardness assessment, and lesion depth was measured in polarized light photomicrographs. In the chemical model (CG), mineral content values in the vicinities of restoration were high for Groups 5 (75.7 +/- 11.9), 4 (70.8 +/- 14.2), and NC (95.4 +/- 3.8); intermediate for Groups 1 (55.8 +/- 18.5), 6 (45.6 +/- 11.0), and 2 (44.3 +/- 11.2); and reduced for Group 3 (34.7 +/- 9.7). In the microbiological model (BG), results were similar to CG, although there was less demineralization. The highest lesion depths were found for Groups 3 (182.3 +/- 33.2) in CG and 6 (126.5 +/- 42.8) in BG, when compared to Group 5 (114.6 +/- 26.0 and 56.2 +/- 33.2, respectively). In both models of caries induction, ionomeric materials showed a superior cariostatic effect when compared to the other restorative materials.

  10. The effect of different drinks on the color stability of different restorative materials after one month

    PubMed Central

    Tuncer, Safa; Demirci, Mustafa; Serim, Merve Efe; Baydemir, Canan

    2015-01-01

    Objectives The aim of this study was to evaluate the effect of three different drinks on the color parameters of four different restorative materials. Materials and Methods Three different composites (Filtek Ultimate Universal Restorative, Filtek Ultimate Flowable, and Filtek Silorane, 3M ESPE) and a polyacid-modified composite resin material (Dyract XP, Dentsply DeTrey GmbH) were evaluated. Eighty-four disc-shaped specimens of 8 mm in diameter and 2 mm in thickness were prepared (n = 21 each). Color coordinates (L*a*b*, ΔL*, Δa*, Δb*, and ΔE*) were measured using a VİTA Easyshade Compact (VİTA Zahnfabrik) after 24 hr of storage (baseline) and after 30 day of storage in three different beverages of black tea, Coca cola, or water (control) (n = 7). In each beverage, the specimens were stored three times a day, one hr each, for 30 day. The color changes (ΔE) were calculated and were analyzed by Kruskal-Wallis and Dunn multiple comparison test. Results The color difference (ΔE*) of the resin materials ranged between 1.31 and 15.28 after 30 day of immersion in the staining solutions. Dyract XP in Coca cola (15.28 ± 2.61) and black tea (12.22 ± 2.73) showed the highest mean ΔE* value after 30 day, followed by Filtek Ultimate Universal Restorative (5.99 ± 1.25) and Filtek Ultimate Flowable (4.71 ± 1.40) in black tea (p < 0.05). Conclusions The compomers displayed unacceptable color changes at the end of 30 day in all beverages. Among resin composites, the silorane based composite exhibited relatively good color stability than the others. Filtek Ultimate Universal Restorative and Filtek Flowable showed similar color changes in all beverages. PMID:26587410

  11. Multi-material laser densification (MMLD) of dental restorations: Process optimization and properties evaluation

    NASA Astrophysics Data System (ADS)

    Li, Xiaoxuan

    This Ph.D. thesis proposes to investigate the feasibility of laser-assisted dental restoration and to develop a fundamental understanding of the interaction between laser beam and dental materials. Traditional dental restorations are produced by the porcelain-fused-to-metal (PFM) process, in which a dental restoration is cast from a metallic alloy and then coated with dental porcelains by multiple furnace-firing processes. PFM method is labor-intensive and hence very expensive. In order to fabricate dental restoration units faster and more cost-effectively, the Solid Freeform Fabrication (SFF) technique has been employed in this study. In particular, a Multi-Material Laser Densification (MMLD) process has been investigated for its potential to fabricate artificial teeth automatically from 3-D computer dental tooth files. Based on the principle of SFF, the MMLD process utilizes a micro-extruder system to deliver commercial dental alloy and porcelain slurry in a computer-controlled pattern line by line and layer by layer. Instead of firing the artificial tooth/teeth in a furnace, the extruded dental materials are laser scanned to convert the loose powder to a fully dense body. Different laser densification parameters including the densification temperature, laser output power, laser beam size, line dimension, ratio of the beam size to line width, beam scanning rate, processing atmosphere and pressure, dental powder state (powder bed or slurry), powder particle size, etc. have been used to evaluate their effects on the microstructures and properties of the laser densified dental body, and hence to optimize MMLD conditions. Furthermore, laser-scanning induced phase transformations in dental porcelains have been studied because the transformations have great impact on coefficient of thermal expansion (CTE) of dental porcelains, which should match that of dental alloy substrate. Since a single dental material line delivered by the MMLD system functions as a "construction

  12. 14 CFR 141.7 - Provisional pilot school certificate.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Provisional pilot school certificate. 141.7... (CONTINUED) SCHOOLS AND OTHER CERTIFICATED AGENCIES PILOT SCHOOLS General § 141.7 Provisional pilot school... provisional pilot school certificate with ratings....

  13. 14 CFR 141.7 - Provisional pilot school certificate.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Provisional pilot school certificate. 141.7... (CONTINUED) SCHOOLS AND OTHER CERTIFICATED AGENCIES PILOT SCHOOLS General § 141.7 Provisional pilot school... provisional pilot school certificate with ratings....

  14. Physical properties of a new sonically placed composite resin restorative material.

    PubMed

    Ibarra, Emily T; Lien, Wen; Casey, Jeffery; Dixon, Sara A; Vandewalle, Kraig S

    2015-01-01

    A new nanohybrid composite activated by sonic energy has been recently introduced as a single-step, bulk-fill restorative material. The purpose of this study was to compare the physical properties of this new composite to various other composite restorative materials marketed for posterior or bulk-fill placement. The following physical properties were examined: depth of cure, volumetric shrinkage, flexural strength, flexural modulus, fracture toughness, and percent porosity. A mean and standard deviation were determined per group. One-way ANOVA and Tukey's post hoc tests were performed per property (α = 0.05). Percent porosity was evaluated with a Kruskal-Wallis/Mann-Whitney test (α = 0.005). Significant differences were found between groups (P < 0.001) per test type. Compared to the other composite restorative materials, the new nanohybrid composite showed low shrinkage and percent porosity, moderate fracture toughness and flexural modulus, and high flexural strength. However, it also demonstrated a relatively reduced depth of cure compared to the other composites.

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

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

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

  16. Heat generation caused by ablation of dental restorative materials with an ultra short pulse laser (USPL) system

    NASA Astrophysics Data System (ADS)

    Braun, Andreas; Wehry, Richard; Brede, Olivier; Frentzen, Matthias; Schelle, Florian

    2011-03-01

    The aim of this study was to assess heat generation in dental restoration materials following laser ablation using an Ultra Short Pulse Laser (USPL) system. Specimens of phosphate cement (PC), ceramic (CE) and composite (C) were used. Ablation was performed with an Nd:YVO4 laser at 1064 nm and a pulse length of 8 ps. Heat generation during laser ablation depended on the thickness of the restoration material. A time delay for temperature increase was observed in the PC and C group. Employing the USPL system for removal of restorative materials, heat generation has to be considered.

  17. Eroded dentin does not jeopardize the bond strength of adhesive restorative materials.

    PubMed

    Cruz, Janaina Barros; Lenzi, Tathiane Larissa; Tedesco, Tamara Kerber; Guglielmi, Camila de Almeida Brandão; Raggio, Daniela Prócida

    2012-01-01

    This in vitro study evaluated the bond strength of adhesive restorative materials to sound and eroded dentin. Thirty-six bovine incisors were embedded in acrylic resin and ground to obtain flat buccal dentin surfaces. Specimens were randomly allocated in 2 groups: sound dentin (immersion in artificial saliva) and eroded dentin (pH cycling model - 3× / cola drink for 7 days). Specimens were then reassigned according to restorative material: glass ionomer cement (KetacTM Molar Easy Mix), resin-modified glass ionomer cement (VitremerTM) or adhesive system with resin composite (Adper Single Bond 2 + Filtek Z250). Polyethylene tubes with an internal diameter of 0.76 mm were placed over the dentin and filled with the material. The microshear bond test was performed after 24 h of water storage at 37ºC. The failure mode was evaluated using a stereomicroscope (400×). Bond strength data were analyzed with two-way ANOVA and Tukey's post hoc tests (α = 0.05). Eroded dentin showed bond strength values similar to those for sound dentin for all materials. The adhesive system showed the highest bond strength values, regardless of the substrate (p < 0.0001). For all groups, the adhesive/mixed failure prevailed. In conclusion, adhesive materials may be used in eroded dentin without jeopardizing the bonding quality. It is preferable to use an etch-and-rinse adhesive system because it shows the highest bond strength values compared with the glass ionomer cements tested. PMID:22714927

  18. Stress distributions in maxillary central incisors restored with various types of post materials and designs.

    PubMed

    Madfa, A A; Kadir, M R Abdul; Kashani, J; Saidin, S; Sulaiman, E; Marhazlinda, J; Rahbari, R; Abdullah, B J J; Abdullah, H; Abu Kasim, N H

    2014-07-01

    Different dental post designs and materials affect the stability of restoration of a tooth. This study aimed to analyse and compare the stability of two shapes of dental posts (parallel-sided and tapered) made of five different materials (titanium, zirconia, carbon fibre and glass fibre) by investigating their stress transfer through the finite element (FE) method. Ten three-dimensional (3D) FE models of a maxillary central incisor restored with two different designs and five different materials were constructed. An oblique loading of 100 N was applied to each 3D model. Analyses along the centre of the post, the crown-cement/core and the post-cement/dentine interfaces were computed, and the means were calculated. One-way ANOVAs followed by post hoc tests were used to evaluate the effectiveness of the post materials and designs (p=0.05). For post designs, the tapered posts introduced significantly higher stress compared with the parallel-sided post (p<0.05), especially along the centre of the post. Of the materials, the highest level of stress was found for stainless steel, followed by zirconia, titanium, glass fibre and carbon fibre posts (p<0.05). The carbon and glass fibre posts reduced the stress distribution at the middle and apical part of the posts compared with the stainless steel, zirconia and titanium posts. The opposite results were observed at the crown-cement/core interface.

  19. Mechanical properties of a permanent dental restorative material based on calcium aluminate.

    PubMed

    Loof, J; Engqvist, H; Ahnfelt, N-O; Lindqvist, K; Hermansson, L

    2003-12-01

    This paper deals with some important mechanical properties (hardness, dimensional stability, compressive and flexural strength) of an experimental version of a translucent calcium aluminate dental restorative material. All samples investigated have been made from pre-pressed tablets, with a compaction degree of approximately 60%, hydrated using a 0.15 wt % Li salt solution as an accelerator. The samples were stored in water at 37 degrees C between the measurements. As reference materials one composite, Tetric Ceram, and one glass ionomer, Fuji II, were used with specimens prepared according to the manufacturer's recommendations. For the reference materials some of the properties were published data. The results show that the calcium aluminate material has sufficient mechanical properties to be used as a permanent dental restorative taking as a reference the ISO 9917 and the ISO 4049 as well as the reference materials. In addition the results indicate that the mechanical properties are controlled by the microstructure, which is mainly determined by the grain size of the filler.

  20. Stress distributions in maxillary central incisors restored with various types of post materials and designs.

    PubMed

    Madfa, A A; Kadir, M R Abdul; Kashani, J; Saidin, S; Sulaiman, E; Marhazlinda, J; Rahbari, R; Abdullah, B J J; Abdullah, H; Abu Kasim, N H

    2014-07-01

    Different dental post designs and materials affect the stability of restoration of a tooth. This study aimed to analyse and compare the stability of two shapes of dental posts (parallel-sided and tapered) made of five different materials (titanium, zirconia, carbon fibre and glass fibre) by investigating their stress transfer through the finite element (FE) method. Ten three-dimensional (3D) FE models of a maxillary central incisor restored with two different designs and five different materials were constructed. An oblique loading of 100 N was applied to each 3D model. Analyses along the centre of the post, the crown-cement/core and the post-cement/dentine interfaces were computed, and the means were calculated. One-way ANOVAs followed by post hoc tests were used to evaluate the effectiveness of the post materials and designs (p=0.05). For post designs, the tapered posts introduced significantly higher stress compared with the parallel-sided post (p<0.05), especially along the centre of the post. Of the materials, the highest level of stress was found for stainless steel, followed by zirconia, titanium, glass fibre and carbon fibre posts (p<0.05). The carbon and glass fibre posts reduced the stress distribution at the middle and apical part of the posts compared with the stainless steel, zirconia and titanium posts. The opposite results were observed at the crown-cement/core interface. PMID:24834856

  1. Reinforcement of conventional glass-ionomer restorative material with short glass fibers.

    PubMed

    Hammouda, Ibrahim M

    2009-01-01

    This study investigated the strengthening effect of glass fibers when added to conventional glass-ionomer restorative material. Glass fibers were incorporated into glass-ionomer powder in 3 wt% and 5 wt%. The fibers used had 1 mm length and 10 microm thickness. These criteria of fiber length, diameter, and concentration represent a new approach for reinforcing conventional glass-ionomer [Medifill, conventional restorative glass-ionomer]. The mechanical properties tested were diametral tensile strength, hardness, flexural strength, flexural modulus and fracture toughness after 24-h and 7-days of storage in deionized water. Glass short fibers were mixed thoroughly into the glass-ionomer powder before mixing with the cement liquid. Samples of specific dimensions were prepared for each time interval and fiber loading according to the manufacturer's instructions and international standards. Hardness was measured using a micro-hardness tester at 100 gram applied load for 15 s. The other mechanical properties were measured using a Lloyd universal testing machine. The results showed increased diametral tensile strength, flexural strength, flexural modulus, and fracture toughness by the addition of glass fibers. There was an appreciable increase of the tested mechanical properties of glass-ionomer restorative material as a result of increasing fiber loading and water storage for 1 week. It was concluded that conventional glass-ionomer can be reinforced by the addition of short glass fibers.

  2. Effect of Whitening Dentifrice on Micro Hardness, Colour Stability and Surface Roughness of Aesthetic Restorative Materials

    PubMed Central

    Basappa, N.; Prabhakar, AR; Raju, OS; Lamba, Gagandeep

    2016-01-01

    Introduction Whitening agents present in the novel whitening dentifrices may have deleterious effects over the aesthetic restorations. Aim The present study evaluated the invitro effect of whitening dentifrice on micro hardness, colour stability and surface roughness on aesthetic restorative materials. Materials and Methods Forty specimens each of compomer and of composite were prepared using brass mould. Specimens were equally divided into 4 groups. Group I (20 disks of compomer are subjected to brushing with conventional tooth paste) Group II (20 disks of composite subjected to brushing with conventional tooth paste), Group III (20 disks of compomer subjected to brushing with whitening tooth paste). Group IV (20 disks of composite subjected to brushing with whitening toothpaste). Each group was further divided into two subgroups, where 10 sample were subjected for two weeks of brushing with respective tooth paste and other 10 were subjected for four weeks of brushing. For the evaluation of micro hardness, colour stability and surface roughness, micro hardness testing machine, spectrophotometer and surface testing machine were used respectively. Initial and final readings were taken for each specimen and difference obtained was subjected to statistical analysis. One-way ANOVA was used for multiple group comparison followed by post-hoc Tukey’s-test. The paried t-test was used for intra group comparison and unpaired t-test for comparing independent sample groups. Results The compomer and composite showed no significant difference in micro hardness either with conventional or whitening tooth paste both at two and four weeks. Although there was a highly significant colour change observed after using whitening tooth paste for both compomer and composite. Regarding surface roughness, there was a significant change in roughness in both conventional and whitening tooth paste with compomer and composite. However, whitening tooth paste had a significant change in surface

  3. Comparison of microleakage from stainless steel crowns margins used with different restorative materials: An in vitro study

    PubMed Central

    Memarpour, Mahtab; Derafshi, Reza; Razavi, Mahshid

    2016-01-01

    Background: Obtaining optimal marginal adaption with prefabricated stainless steel crowns (SSCs) is difficult, especially after removing dental caries or defects in cervical areas. This situation requires the use of an SSC after tooth reconstruction. This study evaluated microleakage and material loss with five restorative materials at SSC margins. Materials and Methods: One hundred and twenty primary molar teeth were randomly divided into six groups (n = 20). Class V cavities were prepared on the buccal surfaces of the teeth in groups 1-5. Cavities were restored with amalgam, resin-based composite, glass ionomer (GI), zinc phosphate, or reinforced zinc oxide eugenol (Zonalin). Group 6 without cavity preparation was used as a control. Restorations with SSCs were prepared according to standard methods. Then, SSCs were fitted so that the crown margins overlaid the restorative materials and cemented with GI. After thermocycling, the specimens were placed in 0.5% fuchsin and sectioned. The proportions of mircoleakage and material loss were evaluated with a digital microscope. Statistical analysis was performed with Kruskal–Wallis and Mann–Whitney tests. Results: The groups differed significantly (P < 0.001). Amalgam and GI showed the least microleakage. Amalgam restorations had significantly less microleakage than the other materials (P < 0.05). Microleakage was greatest with resin-based composite, followed by Zonalin. Material loss was greater in samples restored with Zonalin and zinc phosphate. Conclusion: When SSC margins overlaid the restoration materials, cavity restoration with amalgam or GI before SSC placement led to less microleakage and material loss. Regarding microleakage and material loss, resin-based composite, zinc phosphate, and Zonalin were not suitable options. PMID:26962309

  4. Preservation-based approaches to restore posterior teeth with amalgam, resin or a combination of materials.

    PubMed

    Baghdadi, Ziad D

    2002-02-01

    This review is a systematic assessment, from the literature, of the status quo of dental amalgam, resin-based composite and glass-ionomer restorations for carious lesions as it applies to new concepts, coupled with clinical research. Scientifically based and practical new materials and techniques are recommended to include in contemporary practice throughout the world. Clinical and laboratory studies which have been carried out in light of modern conservative principles, and in light of the current emphasis of treating dental caries as a disease process were reviewed and discussed. An approach to managing carious lesions based upon selected advantages of dental amalgam, resin-based composite and glass-ionomer technology applied to what is termed "preservation-based" approaches to restoring teeth has been synthesized. Researched evidence contradicts the notion of "extension for prevention" in favor of maintaining sound tooth structure which would translate into more patients with healthy dentitions for entire lifetimes. PMID:12074231

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

    NASA Astrophysics Data System (ADS)

    Ragain, James Carlton, Jr.

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

  6. The selection of contemporary restorative materials: anecdote vs. evidence-based?

    PubMed

    Donovan, Terry E

    2006-02-01

    The contemporary practitioner is faced with a bewildering number of options from which to choose when selecting restorative materials. There are not only many different types of materials available, but also numerous options for any given group of materials. For example, many manufacturers offer their customers three or even four different dentin bonding agents. The sheer number of available products is in itself overwhelming. When coupled with aggressive marketing strategies, misinformation supplied by paid clinicians at many seminars and lectures, and infomercials disguised as scientific articles in many of the trade journals, it is little wonder that the average ethical practitioner is frustrated when attempting to make rational choices. Clinicians use information gleaned from a variety of sources to make these difficult decisions. This article will attempt to evaluate the validity of these sources and will provide a philosophical matrix to assist the practitioner in making rational decisions relative to materials selection. PMID:16724468

  7. Use of a light cured periodontal surgical dressing material in temporization: A convenient approach

    PubMed Central

    Singh, W. Bruce Lee; Singh, Saumyendra V.; Pandey, W. Pragya; Solanki, Nehal

    2015-01-01

    Majority of provisional restorations are fabricated directly in the mouth. However, there are several reasons where the direct technique may not be feasible and the clinician might need an indirect method. This report describes the use of a periodontal surgical dressing material (PSD) as a quick solution in such situations, utilizing it for short term temporization till the indirect provisional is fabricated. PSD's may be used for short term temporization in cases where the need of indirect temporization requires a patient to go without a provisional for a few days or the definitive restoration can be delivered in a very short span of time. It also opens up the possibility of single sitting abutment reduction at the time of periodontal surgery, using the pack for a dual purpose-healing & temporization. PMID:26258026

  8. Influence of Curing Light Attenuation Caused by Aesthetic Indirect Restorative Materials on Resin Cement Polymerization

    PubMed Central

    Pick, Bárbara; Gonzaga, Carla Castiglia; Junior, Washington Steagall; Kawano, Yoshio; Braga, Roberto Ruggiero; Cardoso, Paulo Eduardo Capel

    2010-01-01

    Objectives: To verify the effect of interposing different indirect restorative materials on degree of conversion (DC), hardness, and flexural strength of a dual-cure resin cement. Methods: Discs (2 mm-thick, n=5) of four indirect restorative materials were manufactured: a layered glass-ceramic (GC); a heat-pressed lithium disilicate-based glass-ceramic veneered with the layered glass-ceramic (LD); a micro-hybrid (MH); and a micro-filled (MF) indirect composite resin. The light transmittance of these materials was determined using a double-beam spectrophotometer with an integrating sphere. Bar-shaped specimens of a dual-cure resin cement (Nexus 2/SDS Kerr), with (dual-cure mode) and without the catalyst paste (light-cure mode), were photoactivated through the discs using either a quartz-tungsten-halogen (QTH) or a light-emitting diode (LED) unit. As a control, specimens were photoactivated without the interposed discs. Specimens were stored at 37ºC for 24h before being submitted to FT-Raman spectrometry (n=3), Knoop microhardness (n=6) and three-point bending (n=6) tests. Data were analyzed by ANOVA/Tukey’s test (α=0.05). Results: MH presented the highest transmittance. The DC was lower in light-cure mode than in dual-cure mode. All restorative materials reduced the cement microhardness in light-cure mode. GC and LD with QTH and GC with LED decreased the strength of the cement for both activation modes compared to the controls. Curing units did not affect DC or microhardness, except when the dual-cure cement was photoactivated through LD (LED>QTH). Flexural strength was higher with QTH compared to LED. Conclusions: Differences in transmittance among the restorative materials significantly influenced cement DC and flexural strength, regardless of the activation mode, as well as the microhardness of the resin cement tested in light-cure mode. Microhardness was not impaired by the interposed materials when the resin cement was used in dual-cure mode. PMID:20613921

  9. Susceptibility of restorative materials to staining by common beverages: an in vitro study.

    PubMed

    Ayad, Neveen M

    2007-01-01

    The purpose of this study was to determine the staining potential of glass-ionomer and composite resin restorative materials following immersion in common beverages. Nine tooth-colored restorative materials were used: three glass ionomers (ceramic-reinforced, resin-modified, and conventional) and six composite resins (nanofilled, ormocer-based, flowable ormocer-based, polyacid-modified, microhybrid, and flowable microhybrid). Disk-shaped specimens were prepared and immersed in 37 degrees C distilled water for 24 hours. Over a 2-week period, five specimens of each material were immersed daily in one of three test beverages (coffee, tea, or cola), then stored in distilled water. A control group of five specimens of each material was continuously immersed in distilled water during the test period. Color coefficients (CIE Lab) were measured by a spectrophotometer before and after staining. All materials were susceptible to staining by all test beverages, while distilled water caused no perceptible color change. As determined by ANOVA and Bonferroni tests, there were highly significant differences in the change in color (deltaE) for tested materials in different beverages (P < or = .001). The deltaE was significantly higher for coffee and tea than for cola; the deltaE was significantly higher for the polyacid-modified composite resin than for all other materials. The material with the least amount of color change in coffee and tea was the ceramic-reinforced glass ionomer (deltaE = 12.45 and 10.64, respectively) and in cola was the nanofilled composite resin (deltaE = 1.93).

  10. Effects of carbamide peroxide on the staining susceptibility of tooth-colored restorative materials.

    PubMed

    Yu, Hao; Pan, Xinhua; Lin, Yao; Li, Qing; Hussain, Manal; Wang, Yining

    2009-01-01

    This study investigated the effects of an at-home bleaching gel containing 15% carbamide peroxide on the susceptibility of tooth-colored restorative materials to different staining solutions. The tooth-colored restoratives used in this study were a nano resin composite (Filtek Z350), a packable resin composite (Filtek P60), a polyacid-modified composite (Dyract AP) and a glass-ionomer cement (Ketac Molar Easymix). Each material was equally divided into two groups (n = 34): the bleaching group and the control group. This study included two treatment segments. In the first part (days 1-14), the specimens of the bleaching group were bleached with 15% carbamide peroxide gels for eight hours daily, while the specimens in the control group were stored in deionized water. Subsequently, four specimens from each group were randomly selected for observation under an environmental scanning electron microscope. In the second part (days 15-42), the samples were not bleached. Instead, they were stored in five different kinds of solutions. Color measurements for each sample were taken at six different time periods using a spectrophotometer. The data was then analyzed using SPSS statistical software. After two-weeks of bleaching, all the specimens showed statistically significant color changes compared with the control specimens. Furthermore, the bleaching agents seriously affected the surface morphology of Dyract AP and Ketac Molar Easymix. Following exposure to the staining solutions, it was found that the bleached restorative materials exhibited greater staining susceptibility than the control materials. Filtek Z350 and P60 exhibited the best color stability, while Dyract AP exhibited the least color stability. PMID:19192840

  11. Comparative in vitro assessment of color stability of hybrid esthetic restorative materials against various children's beverages

    PubMed Central

    Hotwani, Kavita; Thosar, Nilima; Baliga, Sudhindra

    2014-01-01

    Purpose: The present study was aimed to evaluate and compare the color stability of two hybrid tooth-colored restorative materials, namely, resin-modified glass ionomer cement (GC Fuji II LC Capsules - GC Corporation, Tokyo, Japan) and giomer (Beautifil II - Shofu Inc, Kyoto, Japan) when subjected to immersion in various children's beverages. Materials and Methods: Standardized disc specimens were prepared using the test restorative materials. After preparation and rehydration of the specimens, baseline color evaluations were performed using spectrophotometer. The readings were recorded according to CIELAB color space. The experimental groups were further subdivided for immersion in orange juice, bournvita milk, and coke. Subsequent to immersion and pH cycling, new color evaluations were carried out after 1 week and 4 weeks for all the experimental groups. The mean color change values were calculated. Results: The obtained data was subjected to statistical analysis. The results indicated that giomer specimens exhibited less color change as compared to RMGIC specimens indicating better color stability. The maximum color changes were found with the use of coke for a period of 4 weeks. Conclusion: Amongst the two materials, giomer showed less color changes as compared to RMGIC indicating a better color stability. PMID:24554866

  12. Treatment of traumatic injuries in the front teeth: restorative aspects in crown fractures.

    PubMed

    Dietschi, D; Jacoby, T; Dietschi, J M; Schatz, J P

    2000-10-01

    Crown fractures are the most common form of traumatic dental injuries encountered in permanent dentition. Restorative treatment modalities incorporate adhesive materials to effectively maintain function and aesthetics. While uncomplicated injuries of the enamel and/or dentin can be treated solely with adhesive procedures, complicated trauma that involves pulp exposure requires the incorporation of a multidisciplinary treatment approach. Fragment reattachment is facilitated by the utilization of bonding agents that enhance retention and aesthetics. This article discusses the application of provisional and permanent restorative options for the treatment of complications following traumatic injuries.

  13. Need for informed consent for dentists who use mercury amalgam restorative material as well as technical considerations in removal of dental amalgam restorations.

    PubMed

    Edlich, Richard F; Greene, Jill Amanda; Cochran, Amy A; Kelley, Angela R; Gubler, K Dean; Olson, Brianna M; Hudson, Mary Anne; Woode, Dayna R; Long, William B; McGregor, Walter; Yoder, Carolyn; Hopkins, Debra B; Saepoff, Jessica P

    2007-01-01

    Amalgam restorative material generally contains 50% mercury (Hg) in a complex mixture of copper, tin, silver, and zinc. It has been well documented that this mixture continually emits mercury vapor, which is dramatically increased by chewing, eating, brushing, and drinking hot liquids. Mercury has been demonstrated to have damaging effects on the kidney, central nervous system, and cardiovascular system, and has been implicated in gingival tattoos. While mercury amalgams may result in detrimental exposure to the patient, they can also be a danger in dental practices. In Europe, the federal governments of Norway, Finland, Denmark, and Sweden have enacted legislation requiring that dental patients receive informed consent information about the dental restorative material that will be used. In the United States, a few state governments have enacted informed consent legislation for dental patients receiving dental restorations. These state legislations were enacted by Maine, California, Connecticut, and Vermont. It is a sad tragedy that mercury is causing such health damage to many people. The American Dental Association has said for the past 150 years that the mercury in amalgam is safe and does not leak; however, no clinical studies were ever done and the Food and Drug Administration approved amalgam under a grandfather clause. Subsequent studies have shown this claim of safety not to be true. Over ten years ago, the Federation of American Societies for Experimental Biology Journal published a comprehensive article calling mercury restorative material a major source of mercury exposure to the U.S. population. The authors of this paper recommend that federal and state legislation be passed throughout our country to ensure that consent forms are given to patients receiving silver-mercury amalgam restorative material.

  14. Optical coherence tomography and confocal microscopy investigations of dental structures and restoration materials

    NASA Astrophysics Data System (ADS)

    Negrutiu, Meda L.; Sinescu, Cosmin; Rominu, Mihai; Hughes, Michael; Dobre, George; Podoleanu, Adrian G.

    2009-02-01

    Nowadays, optical tomographic techniques are of particular importance in the medical imaging field, because these techniques can provide non-invasive diagnostic images. The present study evaluates the potential of en-face optical coherence tomography (OCT) as a possible non-invasive high resolution imaging method in supplying the necessary information on the quality of dental hard tissues and defects of dental restorative materials. Teeth after several treatment methods are imaged in order to asses the material defects and micro-leakage of tooth-filling interface as well as to evaluate the quality of dental hard tissue. C-scan and B-scan OCT images as well as confocal images are acquired from a large range of samples. Cracks and voids in the dental structures as well as gaps between the dental interfaces and material defects are clearly exposed. The advantages of the OCT method consist in non-invasiveness and high resolution.

  15. Thermal cycling for restorative materials: does a standardized protocol exist in laboratory testing? A literature review.

    PubMed

    Morresi, Anna Lucia; D'Amario, Maurizio; Capogreco, Mario; Gatto, Roberto; Marzo, Giuseppe; D'Arcangelo, Camillo; Monaco, Annalisa

    2014-01-01

    In vitro tests continue to be an indispensable method for the initial screening of dental materials. Thermal cycling is one of the most widely used procedures to simulate the physiological aging experienced by biomaterials in clinical practice. Consequently it is routinely employed in experimental studies to evaluate materials' performance. A literature review aimed to elucidate test parameters for in vitro aging of adhesive restorations was performed. This study aims to assess whether or not a standardized protocol of thermal cycling has been acknowledged from a review of the literature. An exhaustive literature search, examining the effect of thermal cycling on restorative dental materials, was performed with electronic database and by hand. The search was restricted to studies published from 1998 to August 2013. No language restrictions were applied. The search identified 193 relevant experimental studies. Only twenty-three studies had faithfully applied ISO standard. The majority of studies used their own procedures, showing only a certain consistency within the temperature parameter (5-55°C) and a great variability in the number of cycles and dwell time chosen. A wide variation in thermal cycling parameters applied in experimental studies has been identified. The parameters selected amongst these studies seem to be done on the basis of convenience for the authors in most cases. A comparison of results between studies would appear to be impossible. The available data suggest that further investigations will be required to ultimately develop a standardized thermal cycling protocol.

  16. Clinical evaluation of a medium-filled flowable restorative material as a pit and fissure sealant.

    PubMed

    Autio-Gold, J T

    2002-01-01

    This clinical study evaluated the retention rate and caries protection of a medium-filled (46% volume) flowable restorative material (CuRay-Match, OMNII Oral Pharmaceuticals, West Palm Beach, FL 33409, USA) compared to an unfilled sealant (Delton, Dentsply Caulk, Milford, DE 19963, USA). Using a half-mouth design, sealants were applied on randomly assigned caries-free first and/or second permanent molars of 32 children ranging in age from 6-11 years. A total of 118 teeth were etched, dried and sealed. Teeth were evaluated at one, six and 18-month intervals. After one month, 52 teeth sealed with unfilled sealant were intact compared with 46 sealed with a medium-filled resin, and after six months, 36 teeth sealed with an unfilled sealant were intact compared with 27 that were sealed with a medium-filled resin. After 18 months, 29 teeth were still fully sealed with an unfilled sealant, whereas 18 were sealed with a medium-filled resin. The difference between the two groups was not statistically significant. Regarding caries development, four teeth sealed with a medium-filled material and five teeth sealed with an unfilled sealant were decayed after 18 months. These results indicate that a medium-filled flowable restorative material did not perform better in retention rate and caries increment when compared to an unfilled conventional sealant. However, the effect of the additional techniques, such as the use of bonding agent and fissurotomy on retention rates should be evaluated in further studies.

  17. The assessment of surface roughness and microleakage of eroded tooth-colored dental restorative materials

    PubMed Central

    Hussein, Thulfiqar Ali; Bakar, Wan Zaripah Wan; Ghani, Zuryati Ab; Mohamad, Dasmawati

    2014-01-01

    Objectives: To investigate the effect of acidic solution on surface roughness and microleakage of tooth-colored restorative materials. Materials and Methods: A 160 box-shaped cavities were prepared on the buccal surfaces of 160 human molars, and assigned to four groups: Group A restored with Ketac™ Molar Easymix, Group B with Fuji II™ LC, Group C with Ketac™ N100, and Group D with Filtek™ Z250, and subdivided into study and control groups (n = 20). Study groups were immersed in lemon juice (pH = 2.79) for 24 h, whilst controlgroups in deionized distilled water. All samples were immersed in 2% methylene blue dye, sectioned into two equal halves for surface roughness, and microleakage tests. Data were analyzed using Mann–Whitney and Kruskal–Wallis tests at P < 0.05. Results: There was a significant difference in surface roughness of Ketac™ Molar, Fuji II™ LC, and Ketac™ N100. No significant difference was found in microleakage of Ketac™ Molar and Fuji II™ LC; however, there were significant differences in the gingival margin of Ketac™ N100, and the occlusal margin of Filtek™ Z250. Conclusions: All glass ionomer cements were eroded after exposure to the acidic drink. Filtek™ Z250 and Ketac™ Molar Easymix showed more microleakage. All materials showed more microleakage at the gingival margins. PMID:25506139

  18. Effects of bleaching with carbamide peroxide gels on microhardness of restoration materials.

    PubMed

    Campos, Inger; Briso, André Luiz Fraga; Pimenta, Luiz André Freire; Ambrosano, Gláucia

    2003-01-01

    The objective of this in vitro study was to quantitatively assess the effects of bleaching with 10 and 15% carbamide peroxide (CP) on restoration materials by performing superficial microhardness analysis. Acrylic cylindrical containers (4 x 2 mm) were filled with the following restoration products: Charisma (Heraues Kulzer, Vila Santa Catarina, São Paulo, Brazil), Durafill VS (Heraeus Kulzer), Vitremer (3M, Sumaré, São Paulo, Brazil), Dyract (Dentsply, Petrópolis, Rio de Janeiro, Brazil), and Permite C (SDI, São Paulo, São Paulo, Brazil). Sixty samples were prepared of each restoration material. Twenty samples received bleaching treatment with 10% CP, 20 samples received bleaching treatment with 15% CP, and 20 samples were kept submerged in artificial saliva, which was replaced daily. The treatment consisted of immersion of the specimens in 1 cm3 of CP at 10 and 15% for 6 hours per day during 3 weeks, whereupon the test specimens were washed, dried, and kept immersed in artificial saliva for 18 hours. Then the test and control specimens were analyzed using a microhardness gauge. The Knoop Hardness Number (KHN) was taken for each test and control specimen at five different locations by applying a 25 g force for 20 seconds. The values obtained were transformed into KHNs and the mean was calculated. The data were submitted to statistical analysis by analysis of variance and Tukey test, p < .05. The means/standard deviations were as follows: Charisma: CP 10% 38.52/4.08, CP 15% 34.31/6.13, saliva 37.36/4.48; Durafill VS: CP 10% 18.65/1.65, CP 15% 19.38/2.23, saliva 18.27/1.43; Dyract AP: CP 10% 30.26/2.81, CP 15% 28.64/5.44, saliva 33.88/3.46; Vitremer: CP 10% 28.15/3.04, CP 15% 17.40/3.11, saliva 40.93/4.18; and Permite C: CP 10% 183.50/27.09, CP 15% 159.45/5.78, saliva 215.80/26.15. A decrease in microhardness was observed for the materials Dyract AP, Vitremer, and Permite C after treatment with CP at 10 and 15%, whereas no effect on either of the two

  19. Survey on the teaching and use in dental schools of resin-based materials for restoring posterior teeth.

    PubMed

    Liew, Zunliang; Nguyen, Edward; Stella, Rita; Thong, Irene; Yip, Natalia; Zhang, Felix; Burrow, Michael F; Tyas, Martin J

    2011-02-01

    A survey was conducted of 100 dental schools worldwide to investigate the current teaching of posterior resin composite restorations. A 20 multi-part question questionnaire was emailed to the selected schools. Schools were selected by ability to understand and respond in English. The questionnaire consisted of four open-ended questions and 16 closed questions on topics such as material selection for restoring posterior teeth, preclinical teaching of resin composite for posterior teeth, restoration size, contraindications, matrix placement methods, lining use, adhesive selection and finishing. Forty-six schools responded. The outcomes showed all schools included the teaching of resin composite for posterior restorations but varied. The majority of schools (63%) no longer taught amalgam as the preferred posterior restorative material. Half of the schools surveyed set numerical clinical requirements for restoration placement. Australian schools had no requirements whilst 92% of Asian schools did. There was a consensus that larger restorations were less suitable for resin composite. Selection of adhesives depended on region. Generally, the schools surveyed showed minor variations philosophically in teaching of the use and placement of resin composite restorations.

  20. Reinforcement of Unsupported Enamel by Restorative Materials and Dentin Bonding Agents: An In Vitro Study

    PubMed Central

    Mirzaei, M.; Ghavam, M.; Rostamzadeh, T.

    2010-01-01

    Objective: Preservation of unsupported occlusal enamel after removal of underlying carious dentin may result in maintenance of aesthetics as well as wear resistance against the opposing enamel. This study investigates the influence of different restorative materials and bonding agents on reinforcement of unsupported enamel in molars and compares it with sound dentin. Materials and Methods: In this in vitro study, forty- five extracted human molars were selected and randomly divided into five groups of nine. All lingual cusps were cut off. The dentin underlying the buccal cusps was removed in all groups except the positive control. The negative control group received no restorations. After application of varnish and Panavia F, spherical amalgam (Sina) and after application of Single-Bond (3M), composite resin (Tetric Ceram) was used to replace missing dentin. All specimens were thermocycled, then mounted in acrylic resin using a surveyor. Lingual inclination of facial cusps was positioned horizontally. Load was applied by an Instron machine at a crosshead speed of 10 mm/min until fracture. Data were subjected to ANOVA (one way) and Post hoc Test (Duncan). Results: Statistically significant differences were found between the five groups (P<0.001); however, no significant difference was revealed between bonded amalgam and the positive control groups (P=0.762). Composite and amalgam had the same effect (P=0.642), while the composite and negative group had no significant difference (P=0.056). Conclusion: Bonded amalgam systems (Panavia F) could reinforce the undermined occlusal enamel effectively. PMID:21998780

  1. The Temperature Dependence of Micro-Leakage between Restorative and Pulp Capping Materials by Cu Diffusion

    PubMed Central

    H, Kamalak; A, Mumcu; S, Altin

    2015-01-01

    We used the Cu ions for the leakage analysis between pulp capping and restorative materials. Theoretically, Cu has more advantages than Ag ions due to their smaller radii (rCu2+=73 pm and rAg2+=94 pm), lower mass density (dCu=8.96 g/cm3 and dAg=10.49 g/cm3) and higher radio opacity which can be more useful by X-ray or EDX detectors, cheaper price and more abundance in planet when compared with Ag element which is generally used in the leakage studies. The micro leakage between dental restorations and pulp capping materials has been determined by using Micro Computed Tomography, Scanning Electron Microscopy and EDX analysis. It is found that the leakage has temperature dependent mechanism which increases with the increasing temperature. As a result, using Cu solution for leakage studies in dentine is an effective and easy method which can be used in dental science. PMID:25926897

  2. Bond strength of resin-modified glass ionomer restorative materials using a no-rinse conditioner.

    PubMed

    Suihkonen, Rian W; Vandewalle, Kraig S; Dossett, Jon M

    2012-01-01

    A paste-paste resin-modified glass ionomer (RMGI) restorative material has been introduced recently with a new conditioner that requires no rinsing. The purpose of this study was to compare the shear bond strength of an encapsulated RMGI (Fuji II LC) and a new paste-paste RMGI (Fuji Filling LC) to dentin conditioned with 20% polyacrylic acid (Cavity Conditioner), a new no-rinse conditioner (Self Conditioner,), or no conditioner. Mounted human third molars were flattened and the dentin surface was conditioned. The RMGI restorative materials were mixed and incrementally inserted into a mold and photocured. The specimens were loaded until failure in a universal testing machine after 24 hours of storage in distilled water. Fuji II LC had significantly greater bond strength to dentin than Fuji Filling LC. The use of Cavity Conditioner or Self Conditioner resulted in bond strengths that were not significantly different from each other; however, both produced greater bond strengths than those in the non-conditioned groups. PMID:23220322

  3. Shear Bond Strength of Three Orthodontic Bonding Systems on Enamel and Restorative Materials

    PubMed Central

    Ebeling, Jennifer; Schauseil, Michael; Stein, Steffen; Roggendorf, Matthias; Korbmacher-Steiner, Heike

    2016-01-01

    Objective. The aim of this in vitro study was to determine the shear bond strength (SBS) and adhesive remnant index (ARI) score of two self-etching no-mix adhesives (iBond™ and Scotchbond™) on different prosthetic surfaces and enamel, in comparison with the commonly used total etch system Transbond XT™. Materials and Methods. A total of 270 surfaces (1 enamel and 8 restorative surfaces, n = 30) were randomly divided into three adhesive groups. In group 1 (control) brackets were bonded with Transbond XT primer. In the experimental groups iBond adhesive (group 2) and Scotchbond Universal adhesive (group 3) were used. The SBS was measured using a Zwicki 1120™ testing machine. The ARI and SBS were compared statistically using the Kruskal–Wallis test (P ≤ 0.05). Results. Significant differences in SBS and ARI were found between the control group and experimental groups. Conclusions. Transbond XT showed the highest SBS on human enamel. Scotchbond Universal on average provides the best bonding on all other types of surface (metal, composite, and porcelain), with no need for additional primers. It might therefore be helpful for simplifying bonding in orthodontic procedures on restorative materials in patients. If metal brackets have to be bonded to a metal surface, the use of a dual-curing resin is recommended. PMID:27738633

  4. Cytotoxicity of calcium enriched mixture cement compared with mineral trioxide aggregate and intermediate restorative material.

    PubMed

    Mozayeni, Mohammad A; Milani, Amin S; Marvasti, Laleh A; Asgary, Saeed

    2012-08-01

    Calcium enriched mixture (CEM) cement has been recently invented by the last author. It is composed of calcium oxide, calcium phosphate, calcium silicate and calcium sulphate; however, it has a different chemical composition to mineral trioxide aggregate (MTA). The purpose of this ex vivo study was to investigate the cytotoxicity of CEM cement, and compare it with intermediate restorative material (IRM) and MTA. The materials were tested in fresh and set states on L929 fibroblasts to assess their cytotoxicity. The cell viability responses were evaluated with methyl-tetrazolium bromide assay and Elisa reader at 1, 24 and 168 h (7 days). The tested materials were eluted with L929 culture medium according to international standard organisation 109935 standard. Distilled water and culture medium served as positive and negative controls, respectively. Differences in cytotoxicity were evaluated by one-way anova and t-tests. The cytotoxicity of the materials was statistically different at the three time intervals (P < 0.01). The lowest cytotoxic values recorded were expressed by MTA subgroups followed by CEM cement; IRM subgroups were the most cytotoxic root-end/dental material (P < 0.001). CEM cement and MTA are reasonable alternatives to IRM because of lower cytotoxicity. CEM cement also has good biocompatibility as well as lower estimated cost to MTA and seems to be a promising dental material.

  5. Atraumatic extraction, implant placement and immediate provisionalization.

    PubMed

    Tavarez, Rudys Rodolfo de Jesus; Calixto, Amanda Martins; Maia Filho, Etevaldo Matos; Bandeca, Matheus Coelho; Firoozmand, Leily Macedo; Gomes, Mario Gilson Nina; Malheiros, Adriana Santos

    2014-01-01

    Front tooth extraction typically results in significant loss of hard and soft tissue volume, both in the vestibular-lingual and mesiodistal directions. As these changes can compromise the esthetic results of prosthetic rehabilitation, extraction techniques that cause minimal trauma to the remnant tissues are applied in combination with immediate implant placement to minimize such alterations. The case reported in the present article illustrates a therapeutic plan consisting of atraumatic extraction followed by immediate implant placement and provisionalization. When carefully indicated and planned, our results indicate that this technique may provide promising immediate results relative to the maintenance and stability of the peri-implanted tissues. PMID:25576122

  6. A simple and predictable direct technique for esthetic provisional veneers.

    PubMed

    Young, Careen W

    2004-02-01

    There are a number of different techniques for fabricating provisional veneers. There are direct and indirect techniques involving acrylic or composite resin veneers made with or without a vacuform matrix. This article describes a direct technique for fabricating removable provisional veneers using an auto-polymerizing urethane dimethyacrylate resin and a thermoplastic matrix that may later serve as a stent to be worn with the provisional veneers.

  7. Comparison of fracture resistance of endodontically treated teeth using different coronal restorative materials: An in vitro study

    PubMed Central

    Monga, Prashant; Sharma, Vivek; Kumar, Sukesh

    2009-01-01

    Aim/Objective: To evaluate the in vitro effect of bonded restorations on the fracture resistance of root canal-treated teeth. Materials and Methods: One hundred twenty extracted, maxillary, permanent premolars were collected. After preparing the access cavity, the teeth were biomechanically prepared and obturated. Samples were divided into six groups based on the type of restorative material used to restore them. Teeth were embedded in acrylic resin and their fracture strength was measured using a Universal Testing Machine. Data were evaluated statistically using one-way ANOVA-F and unpaired t-test. Results: Teeth restored with bonded amalgam and composite resin showed higher fracture resistance than those restored with conventional amalgam. Fracture strengths of bonded restorations and intact teeth were not statistically different. The results suggested that the group restored with conventional amalgam had the lowest fracture resistance. No statistically significant differences were found between the bonded amalgam and composite resin groups. Conclusion: Conventional amalgam core showed the least fracture resistance whereas; composite resin and bonded amalgam core showed fracture resistance was similar to that of natural tooth. PMID:20543925

  8. Effect of curing with a plasma light on the properties of polymerizable dental restorative materials.

    PubMed

    Millar, B J; Nicholson, J W

    2001-06-01

    Specimens of light-curable dental restoratives have been prepared using either a conventional dental curing lamp (for 20 or 30 s) or a plasma light (for 1 or 2 s). The specimens were then stored in water until their mass equilibrated, then dried to constant mass. Most specimens lost material in this process but the losses in all specimens cured with the plasma light were significantly greater than those cured with the conventional lights (P < 0.05). Longer cure times gave slightly reduced losses in water in most cases. The specimens were then returned to water and allowed to re-equilibrate and their equilibrium water uptake determined. There was no simple trend in this latter property because elution of loosely bound hydrophilic species may have resulted in a less hydrophilic specimen, whose equilibrium water content was therefore correspondingly lower. Overall, the losses through dissolution in water suggest that plasma curing is less effective for these materials than conventional light curing, as it probably results in material with lower molar mass. The losses for the resin-modified glass-ionomer were much greater than for other materials, and it was concluded that the more rapid polymerization with plasma light caused a significant inhibitation of the acid-base part of the setting process. These findings suggest that long-term durability of materials may be compromised by employing plasma light cure rather than a conventional cure system and further studies of this point are recommended.

  9. Analysis of explosion-induced releases of toxic materials at an environmental restoration project

    SciTech Connect

    Bloom, S.G.; Moon, W.H. Jr.

    1993-06-21

    Prior to 1988, a variety of materials were buried on the US DOE Oak Ridge Reservation. Records of the disposal operations are incomplete and toxic materials may have been placed adjacent to potential explosives. One of the safety concerns in conducting an environmental restoration project at the burial sites, is the possibility of an explosion which could release toxic materials to the atmosphere. A safety analysis examined the consequences of such releases by first postulating an upper bound for the strength of an explosive. A correlation, developed by Steindler and Seefeldt of Argonne National Laboratory, was then used to estimate the amount and particle-size distribution of the material that could become airborne from the explosion. The estimated amount of airborne material was the source term in an atmospheric dispersion model which was used to calculate infinite-time, concentration-time integrals and 5-minute, time- weighted average concentrations at locations down-wind from the explosion. The dispersion model includes particle deposition as a function of particle-size distribution class. The concentration-time integrals and average concentrations were compared to published guidelines to assess the consequences of an accidental explosion.

  10. Immediate Provisionalization and Nonfunctional Loading of a Single Implant in the Maxillary Esthetic Zone: A Clinical Presentation and Parameters for Consideration

    PubMed Central

    Michalakis, Konstantinos X.; Kalpidis, Christos D. R.; Kirmanidou, Yvone; Hirayama, Hiroshi; Calvani, Pasquale Lino; Pissiotis, Argiris L.

    2013-01-01

    Restoration of single tooth loss with implant supported prosthesis is now considered a highly predictable treatment. However, the maxillary anterior region still presents a challenge for both the prosthodontist and the periodontist because of the inherent difficulties encountered in the provisionalization and harmonic incorporation of the definitive prosthesis into patient's dentogingival complex. This paper presents a clinical case of a single implant placed immediately after the extraction of a maxillary central incisor, followed by immediate provisionalization and nonfunctional loading. The surgical and the restorative techniques are described, and the parameters of consideration for this approach are presented. PMID:24383012

  11. Effect of Base and Inlay Restorative Material on the Stress Distribution and Fracture Resistance of Weakened Premolars.

    PubMed

    Souza, A C O; Xavier, T A; Platt, J A; Borges, A L S

    2015-01-01

    The purpose of this study was to evaluate the influence of direct base and indirect inlay materials on stress distribution and fracture resistance of endodontically treated premolars with weakened cusps. Forty healthy human premolars were selected; five were left intact as controls (group C+), and the others were subjected to endodontic treatment and removal of buccal and lingual cusp dentin. Five teeth were left as negative controls (group C-). The remaining 30 teeth were divided into two groups according to the direct base material (glass ionomer [GIC] or composite resin [CR]). After base placement, each group was subjected to extensive inlay preparation, and then three subgroups were created (n=5): no inlay restoration (GIC and CR), restored with an indirect composite resin inlay (GIC+IR and CR+IR), and restored with a ceramic inlay (GIC+C and CR+C). Each specimen was loaded until fracture in a universal testing machine. For finite element analysis, the results showed that the removal of tooth structure significantly affected fracture resistance. The lowest values were presented by the negative control group, followed by the restored and based groups (not statistically different from each other) and all lower than the positive control group. In finite element analysis, the stress concentration was lower in the restored tooth compared to the tooth without restoration, whereas in the restored teeth, the stress concentration was similar, regardless of the material used for the base or restoration. It can be concluded that the inlay materials combined with a base showed similar behavior and were not able to regain the strength of intact tooth structure.

  12. Use of a visible light-cured periodontal dressing material as a temporary restoration for inlay/onlay preparations.

    PubMed

    Apltauer, James J; Silver, Joel; Friedman, Lawrence J; Resnick, Steven J; Berkowitz, Leonard I; Rochlen, Glenn K; Blye, Jeffrey S; Hershkowitz, David H; Berkowitz, Gary S

    2013-01-01

    There are numerous materials that are used as temporaries for inlay and onlay preparations while the permanent restoration is being made. This article looks at 2 types of temporary materials that were placed into inlay or onlay preparations by student dentists: a methylmethacrylate acrylic material (DuraLay Inlay Pattern Resin) and a visible light-cured (VLC) periodontal surgical dressing (Barricaid). The resilience and effectiveness of both products are compared and evaluated for use as temporary restorations in inlay or onlay preparations. The study found that use of the VLC periodontal dressing material offers a novel technique for a quick and efficient method to provide a temporary restoration for various inlay and onlay preparations.

  13. Shear bond strength of bulk-fill and nano-restorative materials to dentin

    PubMed Central

    Colak, Hakan; Ercan, Ertugrul; Hamidi, Mehmet Mustafa

    2016-01-01

    Objectives: Bulk-fill composite materials are being developed for preparation depths of up to 4 mm in an effort to simplify and improve the placement of direct composite posterior restorations. The aim of our study was to compare shear-bond strength of bulk-fill and conventional posterior composite resins. Materials and Methods: In this study, 60 caries free extracted human molars were used and sectioned parallel to occlusal surface to expose midcoronal dentin. The specimens were randomly divided into four groups. Total-etch dentine bonding system (Adper Scotchbond 1XT, 3M ESPE) was applied to dentin surface in all the groups to reduce variability in results. Then, dentine surfaces covered by following materials. Group I: SonicFill Bulk-Fill, Group II: Tetric EvoCeram (TBF), Group III: Herculite XRV Ultra, and Group IV: TBF Bulk-Fill, 2 mm × 3 mm cylindrical restorations were prepared by using application apparatus. Shear bond testing was measured by using a universal testing machine. Kruskal–Wallis and Mann–Whitney U-tests were performed to evaluate the data. Results: The highest value was observed in Group III (14.42 ± 4.34) and the lowest value was observed in Group IV (11.16 ± 2.76) and there is a statistically significant difference between these groups (P = 0.046). However, there is no statistically significant difference between the values of other groups. In this study, Group III was showed higher strength values. Conclusion: There is a need for future studies about long-term bond strength and clinical success of these adhesive and bulk-fill systems. PMID:27011738

  14. Evaluation of Microleakage and Marginal Ridge Fracture Resistance of Primary Molars Restored with Three Restorative Materials: A Comparative in vitro Study

    PubMed Central

    Yeolekar, Tapan Satish; Mukunda, KS; Kiran, NK

    2015-01-01

    ABSTRACT Composite restorations are popular because of their superior esthetics and acceptable clinical performance. But shrinkage is still a drawback. Polymerization shrinkage results in volumetric contraction, leading to deformation of the cusps, microleakage, decrease of marginal adaptation, enamel micro-cracks and postoperative sensitivity. A new class of ring opening resin composite based on silorane chemistry has been introduced with claims of less than 1% shrinkage during polymerization. The present study was conducted to evaluate and compare the ability of low shrink silorane based material, a packable composite and a compomer to resist microleakage in class II restorations on primary molars and evaluate marginal ridge fracture resistance of these materials. Sixty human primary molars were selected. Class II cavities were prepared and the teeth were divided into three groups of twenty each. Groups were as follows group I: low shrink composite resin (Filtek P90). Group II: packable composite (Filtek P60) and Group III: compomer (Compoglass F). Half of the teeth were used for microleakage and the rest for marginal ridge fracture resistance. For microleakage testing, dye penetration method was used with 1% methylene blue dye. Followed by evaluation and grading under stereomicroscope at 10* magnification. Fracture resistance was tested with universal testing machine. It was concluded that low shrink silorane based composite resin showed the least amount of microleakage, whereas compomer showed the highest microleakage. Packable composite resisted fracture of marginal ridge better than other composite resins. Marginal ridge fracture resistance of packable composite was comparable to the intact side. How to cite this article: Yeolekar TS, Chowdhary NR, Mukunda KS, Kiran NK. Evaluation of Microleakage and Marginal Ridge Fracture Resistance of Primary Molars Restored with Three Restorative Materials: A Comparative in vitro Study. Int J Clin Pediatr Dent 2015

  15. Evaluation of Microleakage and Marginal Ridge Fracture Resistance of Primary Molars Restored with Three Restorative Materials: A Comparative in vitro Study.

    PubMed

    Yeolekar, Tapan Satish; Chowdhary, Nagalakshmi Ramesh; Mukunda, K S; Kiran, N K

    2015-01-01

    Composite restorations are popular because of their superior esthetics and acceptable clinical performance. But shrinkage is still a drawback. Polymerization shrinkage results in volumetric contraction, leading to deformation of the cusps, microleakage, decrease of marginal adaptation, enamel micro-cracks and postoperative sensitivity. A new class of ring opening resin composite based on silorane chemistry has been introduced with claims of less than 1% shrinkage during polymerization. The present study was conducted to evaluate and compare the ability of low shrink silorane based material, a packable composite and a compomer to resist microleakage in class II restorations on primary molars and evaluate marginal ridge fracture resistance of these materials. Sixty human primary molars were selected. Class II cavities were prepared and the teeth were divided into three groups of twenty each. Groups were as follows group I: low shrink composite resin (Filtek P90). Group II: packable composite (Filtek P60) and Group III: compomer (Compoglass F). Half of the teeth were used for microleakage and the rest for marginal ridge fracture resistance. For microleakage testing, dye penetration method was used with 1% methylene blue dye. Followed by evaluation and grading under stereomicroscope at 10* magnification. Fracture resistance was tested with universal testing machine. It was concluded that low shrink silorane based composite resin showed the least amount of microleakage, whereas compomer showed the highest microleakage. Packable composite resisted fracture of marginal ridge better than other composite resins. Marginal ridge fracture resistance of packable composite was comparable to the intact side. How to cite this article: Yeolekar TS, Chowdhary NR, Mukunda KS, Kiran NK. Evaluation of Microleakage and Marginal Ridge Fracture Resistance of Primary Molars Restored with Three Restorative Materials: A Comparative in vitro Study. Int J Clin Pediatr Dent 2015;8(2):108-113.

  16. Comparative study of mechanical properties of dental restorative materials and dental hard tissues in compressive loads

    PubMed Central

    Lee, Jong Yeop

    2014-01-01

    There are two objectives. One is to show the differences in the mechanical properties of various dental restorative materials compared to those of enamel and dentin. The other is to ascertain which dental restorative materials are more suitable for clinical treatments. Amalgam, dental ceramic, gold alloy, dental resin, zirconia, and titanium alloy were processed as dental restorative material specimens. The specimens (width, height, and length of 1.2, 1.2, and 3.0 mm, respectively) were compressed at a constant loading speed of 0.1 mm/min. The maximum stress (115.0 ± 40.6, 55.0 ± 24.8, 291.2 ± 45.3, 274.6 ± 52.2, 2206.0 ± 522.9, and 953.4 ± 132.1 MPa), maximum strain (7.8% ± 0.5%, 4.0% ± 0.1%, 12.7% ± 0.8%, 32.8% ± 0.5%, 63.5% ± 14.0%, and 45.3% ± 7.4%), and elastic modulus (1437.5 ± 507.2, 1548.4 ± 583.5, 2323.4 ± 322.4, 833.1 ± 92.4, 3895.2 ± 202.9, and 2222.7 ± 277.6 MPa) were evident for amalgam, dental ceramic, gold alloy, dental resin, zirconia, and titanium alloy, respectively. The reference hardness value of amalgam, dental ceramic, gold alloy, dental resin, zirconia, and titanium alloy was 90, 420, 130–135, 86.6–124.2, 1250, and 349, respectively. Since enamel grinds food, its abrasion resistance is important. Therefore, hardness value should be prioritized for enamel. Since dentin absorbs bite forces, mechanical properties should be prioritized for dentin. The results suggest that gold alloy simultaneously has a hardness value lower than enamel (74.8 ± 18.1), which is important in the wear of the opposing natural teeth, and higher maximum stress, maximum strain, and elastic modulus than dentin (193.7 ± 30.6 MPa, 11.9% ± 0.1%, 1653.7 ± 277.9 MPa, respectively), which are important considering the rigidity to absorb bite forces. PMID:25352921

  17. Effect of fiber orientation and type of restorative material on fracture strength of the tooth

    PubMed Central

    Moezizadeh, Maryam; Shokripour, Mohadeseh

    2011-01-01

    Aim: To determine the effect of fiber and its orientation on the fracture resistance of composite restorations in root-filled premolars. Materials and Methods: 50 sound human premolars were collected and assigned to five groups of ten specimens each. In group 1 (control), specimens were not root-filled. In the other four groups, MOD cavities were prepared and the cusps were reduced to 1.5 mm. In groups 2 and 3, the samples were filled with Z-250 and spectrum composites respectively without fiber reinforcement. Groups 4 and 5 were reinforced with Fiber-Ribbon-(Angelus) and restored with spectrum composite. Fibers were placed in the U-shaped design in group 4 while they were placed in the cross-shape in occlusal region in group 5. The fracture resistance was tested using a mechanical testing machine at crosshead speed of 1mm/min. Results: The fracture strength of control group was 1271.16±722.04 N while it was 952.05±330.16 N for group 2, 918.52±256.6 N for group 3, 857.13±184.58 N for group 4 and 1138.81±406.64 N for group 5. Fracture strength of group 5 was more than other groups except for group 1, there was no statistically significant differences. Conclusions: The reinforcement of composite with fiber does not increase fracture resistance of root-filled premolars significantly. PMID:22144799

  18. Effect of artificial saliva contamination on adhesion of dental restorative materials.

    PubMed

    Shimazu, Kisaki; Karibe, Hiroyuki; Ogata, Kiyokazu

    2014-01-01

    The purpose of this study was to evaluate the effects of artificial saliva contamination on three restorative materials, namely, a glass ionomer cement (GIC), a resin-modified GIC (RMGIC), and a composite resin (CR), for which two different etching adhesive systems were used. Thus, three surface conditions were created on bovine teeth using artificial saliva: control, mild saliva contamination, and severe saliva contamination. The dentin bond strength for CR was significantly lower after artificial saliva contamination. There were, however, no significant differences among the three surface conditions in terms of the dentin and enamel bond strengths of GIC and RMGIC. Moreover, CR exhibited significantly greater microleakage after artificial saliva contamination, whereas no significant differences were found in GIC and RMGIC. The results showed that artificial saliva contamination did not affect the shear bond strengths of GIC and RMGIC or their degrees of microleakage.

  19. An investigation of the shear bond strength of compomer restorative material to enamel and dentine.

    PubMed

    Gray, G B; Kataria, V; McManus, S; Jagger, D C

    2006-01-01

    The aim of this study was to investigate the effect of one step adhesives on the shear bond strength of a compomer restorative material to both enamel and dentine. Human extracted teeth were used for the study. Ten samples were prepared for both enamel and dentine specimens for each of the five groups: Tooth, no etch, Prime and Bond NT (P+B NT); tooth, Non-Rinse Conditioner (NRC), P+B NT; tooth, NRC, Prime and Bond 2.1 (P+B 2.1); tooth, etch, P+B NT; tooth, etch, P+B 2.1. The specimens were subjected to bond testing. The shear bond strength was measured using an Inston 1193 testing machine using a cross head speed of 1 mm/minute. The specimens were tested to destruction. The results show that for the enamel specimens the highest bond strength was recorded for those specimens subjected to Etch, P+B 2.1 (22.1 MPa) and Etch P+B NT (20.0 MPa). The groups of specimens which did not undergo etching had very low bond strengths ranging from 11.4 MPa for NRC, P+B 2.1, 8.5 MPa for NRC P+B NT to 6.9 MPa for P+B NT. For the dentine specimens, for all of the groups, the shear bond strengths were low. Those groups subjected to etching produced the highest values of 7.9 MPa for NRC P+B 2.1 with the lowest value of 6.1 MPa for NRC P+B NT. These bond strengths were significantly lower than those achieved for bonding to enamel. Prime and Bond NT and Prime and Bond 2.1, used in conjunction with acid etching, produce satisfactory bond strengths of compomer restorative material to enamel. Bond strengths to dentine were low.

  20. Characteristics of pristine volcanic materials: Beneficial and harmful effects and their management for restoration of agroecosystem.

    PubMed

    Anda, Markus; Suparto; Sukarman

    2016-02-01

    Eruption of Sinabung volcano in Indonesia began again in 2010 after resting for 1200 years. The volcano is daily emitting ash and pyroclastic materials since September 2013 to the present, damaging agroecosystems and costing for management restoration. The objective of the study was to assess properties and impacts of pristine volcanic material depositions on soil properties and to provide management options for restoring the affected agroecosytem. Land satellite imagery was used for field studies to observe the distribution, thickness and properties of ashfall deposition. The pristine ashfall deposits and the underlying soils were sampled for mineralogical, soluble salt, chemical, physical and toxic compound analyses. Results showed that uneven distribution of rainfall at the time of violent eruption caused the areas receiving mud ashfall developed surface encrustation, which was not occur in areas receiving dry ashfall. Ashfall damaged the agroecosytem by burning vegetation, forming surface crusts, and creating soil acidity and toxicity. X-ray diffraction (XRD) and scanning electron microscope (SEM) analyses of encrustated layer indicated the presence of gypsum and jarosite minerals. Gypsum likely acted as a cementing agent in the formation of the encrustation layer with extremely low pH (2.9) and extremely high concentrations of Al, Ca and S. Encrustation is responsible for limited water infiltration and root penetration, while the extremely high concentration of Al is responsible for crop toxicity. Mud ashfall and dry ashfall deposits also greatly changed the underlying soil properties by decreasing soil pH and cation exchange capacity and by increasing exchangeable Ca, Al, and S availability. Despite damaging vegetation in the short-term, the volcanic ashfall enriched the soil in the longer term by adding nutrients like Ca, Mg, K, Na, P, Si and S. Suggested management practices to help restore the agroecosystem after volcanic eruptions include: (i) the

  1. Characteristics of pristine volcanic materials: Beneficial and harmful effects and their management for restoration of agroecosystem.

    PubMed

    Anda, Markus; Suparto; Sukarman

    2016-02-01

    Eruption of Sinabung volcano in Indonesia began again in 2010 after resting for 1200 years. The volcano is daily emitting ash and pyroclastic materials since September 2013 to the present, damaging agroecosystems and costing for management restoration. The objective of the study was to assess properties and impacts of pristine volcanic material depositions on soil properties and to provide management options for restoring the affected agroecosytem. Land satellite imagery was used for field studies to observe the distribution, thickness and properties of ashfall deposition. The pristine ashfall deposits and the underlying soils were sampled for mineralogical, soluble salt, chemical, physical and toxic compound analyses. Results showed that uneven distribution of rainfall at the time of violent eruption caused the areas receiving mud ashfall developed surface encrustation, which was not occur in areas receiving dry ashfall. Ashfall damaged the agroecosytem by burning vegetation, forming surface crusts, and creating soil acidity and toxicity. X-ray diffraction (XRD) and scanning electron microscope (SEM) analyses of encrustated layer indicated the presence of gypsum and jarosite minerals. Gypsum likely acted as a cementing agent in the formation of the encrustation layer with extremely low pH (2.9) and extremely high concentrations of Al, Ca and S. Encrustation is responsible for limited water infiltration and root penetration, while the extremely high concentration of Al is responsible for crop toxicity. Mud ashfall and dry ashfall deposits also greatly changed the underlying soil properties by decreasing soil pH and cation exchange capacity and by increasing exchangeable Ca, Al, and S availability. Despite damaging vegetation in the short-term, the volcanic ashfall enriched the soil in the longer term by adding nutrients like Ca, Mg, K, Na, P, Si and S. Suggested management practices to help restore the agroecosystem after volcanic eruptions include: (i) the

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

    PubMed

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

    2015-01-01

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

  3. 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

  4. 21 CFR 81.1 - Provisional lists of color additives.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... affecting § 81.1, see the List of CFR Sections Affected, which appears in the Finding Aids section of the... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Provisional lists of color additives. 81.1 Section... GENERAL SPECIFICATIONS AND GENERAL RESTRICTIONS FOR PROVISIONAL COLOR ADDITIVES FOR USE IN FOODS,...

  5. 21 CFR 81.1 - Provisional lists of color additives.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... affecting § 81.1, see the List of CFR Sections Affected, which appears in the Finding Aids section of the... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Provisional lists of color additives. 81.1 Section... GENERAL SPECIFICATIONS AND GENERAL RESTRICTIONS FOR PROVISIONAL COLOR ADDITIVES FOR USE IN FOODS,...

  6. 21 CFR 81.1 - Provisional lists of color additives.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... affecting § 81.1, see the List of CFR Sections Affected, which appears in the Finding Aids section of the... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Provisional lists of color additives. 81.1 Section... GENERAL SPECIFICATIONS AND GENERAL RESTRICTIONS FOR PROVISIONAL COLOR ADDITIVES FOR USE IN FOODS,...

  7. 21 CFR 81.1 - Provisional lists of color additives.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... affecting § 81.1, see the List of CFR Sections Affected, which appears in the Finding Aids section of the... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Provisional lists of color additives. 81.1 Section... GENERAL SPECIFICATIONS AND GENERAL RESTRICTIONS FOR PROVISIONAL COLOR ADDITIVES FOR USE IN FOODS,...

  8. 21 CFR 81.1 - Provisional lists of color additives.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... affecting § 81.1, see the List of CFR Sections Affected, which appears in the Finding Aids section of the... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Provisional lists of color additives. 81.1 Section... GENERAL SPECIFICATIONS AND GENERAL RESTRICTIONS FOR PROVISIONAL COLOR ADDITIVES FOR USE IN FOODS,...

  9. Effective dentin restorative material based on phosphate-terminated dendrimer as artificial protein.

    PubMed

    Zhang, Hui; Yang, Jiaojiao; Liang, Kunneng; Li, Jiyao; He, Libang; Yang, Xiao; Peng, Shuangjuan; Chen, Xingyu; Ding, Chunmei; Li, Jianshu

    2015-04-01

    In clinic, it calls for effective and simple materials to repair etched dentin. Bioinspired by the natural mineralization process guided by noncollagenous proteins (NCPs), in this work, we synthesized the fourth generation phosphate-terminated polyamidoamine dendrimer (G4-PO3H2) by one-step modification. We used FT-IR and 1H NMR to characterize the structure of G4-PO3H2, and MTT assay to prove its biocompatibility. It was applied as the analog of dentin phosphophoryn (DPP: a type of NCPs) to repair dentin, due to its similar dimensional scale, topological architecture and peripheral functionalities to that of DPP. By the characterization of SEM and XRD, the effective regeneration of human dentin induced by G4-PO3H2 is characterized and illustrated both in vitro (artificial saliva) and in vivo (oral cavity of rats). It is noted that the thickness of the regenerated mineral layers are more than 10 μm both in vitro and in vivo. The design strategy of G4-PO3H2 may be valuable for researchers in the fields of material science, stomatology and medicine to prepare various promising restorative nano-materials for biomineralized hard tissues such as bone and teeth.

  10. The effectiveness of four methods for stain removal from direct resin-based composite restorative materials

    PubMed Central

    Al-Nahedh, Hend Nahedh; Awliya, Wedad Yassin

    2013-01-01

    Background/purpose Few studies investigated the best method for removing stains from different types of resin-based composite restorations and compared them to the more recently introduced nanocomposites. This study compared the effect of four methods for stain removal from composite resins; finishing with Sof-lex disks, using pumice and brush, bleaching with 10% carbamide peroxide and 38% hydrogen peroxide. Materials and methods Twenty disk specimens were prepared. Specimens were immersed in a staining solution for 3 weeks. The stained surfaces of five specimens from each RBC material were treated with one of the treatment procedures. Colorimetric measurements were taken using spectrophotometer prior to and after staining, and then repeated after surface treatments. Color difference values were calculated. Results One-way ANOVA indicated significant differences in color change of the three composite resin materials following staining. Filtek Z250 showed the least susceptibility to discoloration followed by Renamel, Filtek Supreme was the material most prone to discoloration. Two-way ANOVA and Tukey’s Post Hoc showed that all stain removing procedures except polishing with pumice, were able to return Filtek Z250 to clinically acceptable color difference. While bleaching with 38% carbamide peroxide was not effective with Renamel. Only pumice and 10% carbamide peroxide were able to return Renamel to clinically acceptable color difference. Conclusion Compositions of resin-based composite resins play an important role in their susceptibility to stain and their amenability to stain removal procedures. Home bleaching showed good results for the three materials, while office bleach was the least effective. PMID:24748758

  11. Open Photoacoustic Cell Technique as a Tool for Thermal and Thermo-Mechanical Characterization of Teeth and Their Restorative Materials

    NASA Astrophysics Data System (ADS)

    Pichardo-Molina, J. L.; Gutiérrez-Juárez, G.; Huerta-Franco, R.; Vargas-Luna, M.; Cholico, P.; Alvarado-Gil, J. J.

    2005-01-01

    The thermal diffusivity and thermal expansion coefficient of teeth and three of their most common restorative materials (Amalgam Phase Alloy, Ionomer Fuji II LC, and Resin 3MFPITEK Lutine TMZ250) were studied by means of the open photoacoustic technique. These results were then used as a basis for the theoretical simulation of the photothermal process taking place as a consequence of modulated illumination of a two-layer system formed by the tooth and the restorative material. The model accounts for the coupling of thermal waves and thermoelastic vibration in the two-layer system.

  12. An evaluation of microleakage of various glass ionomer based restorative materials in deciduous and permanent teeth: An in vitro study

    PubMed Central

    Singla, Teena; Pandit, I.K.; Srivastava, Nikhil; Gugnani, Neeraj; Gupta, Monika

    2011-01-01

    Aim To evaluate the microleakage of recently available glass ionomer based restorative materials (GC Fuji IX GP, GC Fuji VII, and Dyract) and compare their microleakage with the previously existing glass ionomer restorative materials (GC Fuji II LC) in primary and permanent teeth. Method One hundred and fifty (75 + 75) non-carious deciduous and permanent teeth were restored with glass ionomer based restorative materials after making class I cavities. Samples were subjected to thermocycling after storing in distilled water for 24 h. Two coats of nail polish were applied 1 mm short of restorative margins and samples sectioned buccolingually after storing in methylene blue dye for 24 h. Microleakage was assessed using stereomicroscope. Result Significant differences (P < 0.05) were found when inter group comparisons were done. Except when GC Fuji VII (Group III) was compared with GC Fuji II LC (Group II) and Dyract (Group IV), non-significant differences (P > 0.05) were observed. It was found that there was no statistically significant difference when the means of microleakage of primary teeth were compared with those of permanent teeth. Conclusions GC Fuji IX GP showed maximum microleakage and GC Fuji VII showed least microleakage. PMID:23960526

  13. Influence of Cavity Preparation with Er,Cr:YSGG Laser and Restorative Materials on In Situ Secondary Caries Development

    PubMed Central

    Jorge, Ana Carolina Tedesco; Cassoni, Alessandra; de Freitas, Patrícia Moreira; Reis, André Figueiredo; Junior, Aldo Brugnera

    2015-01-01

    Abstract Objective: The aim of this study was to evaluate the influence of cavity preparation and restorative materials containing fluorides in the prevention of secondary caries lesion development in situ. Methods: A total of 120 blocks obtained from human teeth were divided into two groups and standardized cavities were prepared using diamond burs (DB) or Er,Cr:YSGG-laser [20 Hz, 4.0W, 55% water, 65% air (LA)]. They were divided into three subgroups according to the restorative material (n=20): glass-ionomer cement (GI), resin modified glass-ionomer (RM) or composite resin (CR). Blocks were fixed in palatal intra-oral appliances worn in situ by 20 human volunteers, who dropped 20% sucrose solution eight times daily. After 21 days, blocks were removed and restorations were cross-sectioned to evaluate microhardness [Knoop hardness number (KHN)] underneath enamel surface from 30 to 200 μm. Factors “cavity preparation,” “restorative materials,” and “depth” were evaluated by three way ANOVA, followed by Tukey test (p<0.05). Results: The results showed lower microhardness in cavities prepared with DB than in cavities prepared with LA. At 30 μm, there were no statistical significant differences with regard to “cavity preparation” or “restorative materials” factors. In depth evaluation, the enamel microhardness progressively increased as a function of depth for the GI groups. In the groups prepared with LA at 60 μm/90 μm, there were no significant differences between GI and RM materials, whose microhardnesses were significantly higher than that of CR. Conclusions: Cavity preparation using Er,Cr:YSGG laser increases caries resistance of enamel walls, and reduce caries lesion depth development regardless of fluoride presence in the restorative material. CR showed higher caries lesion development than GI, and RM showed intermediate results. PMID:25654424

  14. Alternative fabrication method for chairside fiber-reinforced composite resin provisional fixed partial dentures.

    PubMed

    Ballo, Ahmed; Vallittu, Pekka

    2011-01-01

    A high level of clinical skill is required for fabricating a provisional fixed partial denture with fiber-reinforced composite resin (FRC) using either the direct or chairside technique. The freehand approach to restoring missing teeth represents a challenge to the clinician, particularly when shaping and finishing a hygienic pontic. This technical report describes a simplified method for chairside fabrication of a fixed dental prosthesis with FRC. It is based on using a translucent template to guide the buildup procedure and to ensure optimal anatomy and function. PMID:21909486

  15. Preservation & Restoration.

    ERIC Educational Resources Information Center

    Online-Offline, 2000

    2000-01-01

    This theme issue on preservation and restoration presents selected resources for elementary and secondary education that include Web sites, CD-ROM and software, videos, books, magazines, and professional resources as well as classroom activities. Age levels are specified for most materials. I Sidebars discuss restoring a masterpiece, a bug's life,…

  16. Dentin bonding performance and interface observation of an MMA-based restorative material.

    PubMed

    Shinagawa, Junichi; Inoue, Go; Nikaido, Toru; Ikeda, Masaomi; Sadr, Alireza; Tagami, Junji

    2016-07-30

    The purpose of this study was to evaluate bonding performance and dentin interface acid resistance using a 4-META/MMA-TBB based restorative material (BF) compared to a conventional 4-META/MMA-TBB resin cement (SB), and the effect of sodium fluoride (NaF) addition to the materials. Dentin surfaces were treated with 10% citric acid-3% ferric chloride (10-3) or 4-META containing self-etching primer (TP), followed by application of BF or SB polymer powders with or without NaF, to evaluate microtensile bond strength (µTBS) in six experimental groups; 10-3/SB, 10-3/BF, TP/SB, TP/BF, TP/SB/NaF and TP/BF/NaF. SEM observation of the resin-dentin interface was performed after acid-base challenge to evaluate interfacial dentin resistance to acid attack. TP/BF showed highest µTBS, while NaF polymers decreased µTBS. TP/BF showed funnel-shaped erosion at the interface, however, NaF polymers improved acid resistance of interface. In conclusion, BF demonstrated high µTBSs and low acid-resistance at the interface. NaF addition enhanced acid resistance but decreased µTBS.

  17. Non-destructive and micro-invasive testing techniques for characterizing materials, structures and restoration problems in mural paintings

    NASA Astrophysics Data System (ADS)

    Tortora, Mariagrazia; Sfarra, Stefano; Chiarini, Marco; Daniele, Valeria; Taglieri, Giuliana; Cerichelli, Giorgio

    2016-11-01

    In this paper, chemical and structural studies of medieval wall paintings in Ocre (L'Aquila, Italy) are presented. During the latest restoration campaign, non-destructive (Near-Infrared Reflectography and Infrared Thermography) and micro-invasive (Nuclear Magnetic Resonance, Fourier Transform Infrared Spectroscopy, μ-Raman, Scanning Electron Microscopy with X-ray Microanalysis, X-Ray Diffraction, X-Ray Fluorescence, Optical Microscopy, Mass Spectrometry, Thermogravimetry) analyses were performed in order to determine the detachments of wall surfaces and the characterization of original and restoration materials. Data integration allowed to reconstruct the conservative history, the execution techniques and the conservation problems of the artefact, as well as to assess the effectiveness of restoration activities adopted. The combined use of physical and micro-chemical techniques proved to be effective for an in-depth study of materials stratification of paintings.

  18. The use of adhesive metal-ceramic restorations as an alternative to conventional crown and bridge materials.

    PubMed

    Bishop, K; Priestley, D; Deans, R; Joshi, R

    1997-02-01

    A compromise is often necessary when choosing the most appropriate material in the construction of crowns and bridges. The most commonly used material is porcelain fused to metal since it is aesthetic and has acceptable physical characteristics to be used in the restoration of both anterior and posterior teeth. Unfortunately, to achieve a predictable and durable result extensive tooth preparation is invariably necessary. More conservative alternatives such as dentine-bonded crowns may have inferior physical characteristics and allow less predictable control over the occlusal contour. This paper describes the construction of fixed restorations which use both lost wax and refractory die techniques in their construction. This results in a restoration which has the combined advantages of both traditional porcelain fused to metal and dentine-bonded crowns and bridges.

  19. Esthetic rehabilitation of anterior discolored teeth with lithium disilicate all-ceramic restorations.

    PubMed

    Prevedello, Gustavo Costa; Vieira, Marcelo; Furuse, Adilson Yoshio; Correr, Gisele Maria; Gonzaga, Carla Castiglia

    2012-01-01

    The esthetic treatment of darkened anterior teeth represents a great challenge to dentists, because dental materials ideally should match the natural teeth. The optical behavior of the final restoration is determined by the color of the underlying tooth structure, the color of the luting agent, and the thickness and opacity of the ceramic material used. This article reports a case in which veneers and full crowns made of heat-pressed, lithium disilicate glass-ceramic were used for the esthetic rehabilitation of anterior discolored teeth. The patient was referred for treatment with defective anterior composite resin restorations, provisional acrylic resin crowns, darkening of the gingival margins, and uneven gingival contours. The multidisciplinary treatment plan included dental bleaching, periodontal plastic surgery to create gingival symmetry, and indirect all-ceramic restorations using high-opacity lithium disilicate glass-ceramic ingots. The treatment was successful and an excellent esthetic result was achieved.

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

    NASA Astrophysics Data System (ADS)

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

    2007-07-01

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

  1. 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

  2. Transition from failing dentition to a fixed implant-supported restoration: a staged approach.

    PubMed

    Cordaro, Luca; Torsello, Ferrucio; Ercoli, Carlo; Gallucci, German

    2007-10-01

    This article describes a staged approach to provide a fixed restoration to patients with a hopeless dentition without a removable provisional phase. The rehabilitation protocol, which includes initial conservative periodontal care, starts with strategic extraction of some of the remaining teeth. The aim of the first step is to permit implant placement and to strategically keep residual teeth as abutments for a provisional fixed denture during the implant healing period. After the implants have osseointegrated, abutment connection is performed, residual teeth are extracted and, simultaneously, a second group of implants is placed. A second fixed provisional restoration is delivered to the patient. After the second group of implants has healed, the patient is ready to undergo normal prosthetic treatment. Advantages of the technique include no removable provisional prosthesis, soft tissue management, preserved function and enhanced esthetics during treatment, and prosthetically driven implant placement. The main drawbacks are extended treatment time, adjustments of the provisional restorations, and no less than two surgical steps.

  3. [A comparative study of mechanical properties of materials for custom-made impression trays used by implant-fixed restorations].

    PubMed

    Gvetadze, R Sh; Abramian, S V; Rusanov, F S; Nubarian, A P; Ivanov, A A

    2012-01-01

    Materials for custom-made impression trays used for impression by implant fixed restorations were compared in the study. The analysis included such values as flexural strength and elasticity modulus, impression material adhesion strength with the use of adhesive and without it. Light-cured plastic Elite LC Tray had the best rates of bending strength and elasticity modulus and the Protakril M had the highest adhesion strength both with and without adhesive.

  4. The potential of novel native plant materials for the restoration of novel ecosystems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aldo Leopold is considered by many to be the father of restoration ecology in North America. While a professor of wildlife management at the University of Wisconsin, he labored 13 years to restore a functioning ecosystem to badly damaged Sauk County farmland that he purchased at the height of the G...

  5. Physicomechanical properties of a zinc-reinforced glass ionomer restorative material.

    PubMed

    Al-Angari, Sarah S; Hara, Anderson T; Chu, Tien-Min; Platt, Jeffrey; Eckert, George; Cook, N Blaine

    2014-03-01

    We compared a zinc-reinforced glass ionomer restorative material (ChemFil Rock) with three commercially available glass ionomer cements (GICs), namely, Fuji IX GP Extra, Ketac Molar Quick Aplicap, and EQUIA Fil, with respect to fracture toughness, microhardness, roughness, and abrasive wear. Fracture toughness (KIC) was tested according to ISO 13586 (n = 10). Hardness, roughness, and abrasive wear were also tested (n = 9). Data were analyzed using the Wilcoxon rank-sum test with adjustment for multiple comparisons (α = 0.05). As compared with the other GICs ChemFil Rock exhibited a greater increase in surface roughness (P < 0.05) and lower microhardness (P < 0.01). The wear resistance of ChemFil Rock was comparable to that of the other GICs (P > 0.05). ChemFil Rock had significantly lower fracture toughness as compared with EQUIA Fil (P = 0.01) and significantly higher fracture toughness as compared with the other GICs (P < 0.02). In conclusion, as compared with the three other commercially available GICs, ChemFil Rock had intermediate fracture toughness, the lowest microhardness, and the greatest change in surface roughness.

  6. PROVISIONAL ADVISORY LEVELS (PALs) FOR PHOSGENE (CG)

    SciTech Connect

    Glass-Mattie, Dana F; McClanahan, Mark; Koller, Loren; Adeshina, Femi; Ross, Robert Hord

    2009-01-01

    The PAL protocol was applied to estimate inhalation exposure limits for phosgene (CG). Data on humans are limited to occupational exposures or accounts from the use of phosgene as a chemical warfare agent in WWI. Animal studies with phosgene show a steep dose-response curve for pulmonary edema and mortality with little species variability in effects. Although immediately upon exposure lacrimation and upper respiratory irritation can occur, the main effect in the target organ, a progressive pulmonary edema, occurs after a latency period of 1-24 hours. PAL estimates were approved by the Expert Consultation Panel for Provisional Advisory Levels in May 2007. Exposure limits for oral exposure to CG are not developed due to insufficient data. PAL estimates for inhalation exposure to CG are presented: The 24-hour PAL values for severity levels 1, 2, and 3 are 0.0017, 0.0033 and 0.022 ppm, respectively. The 30-day PAL values are 0.0006 and 0.0012 ppm for the PAL 1 and 2 values, respectively. These 30-day inhalation values were also accepted as the 90-day and 2-year PAL 1 and 2 values. Data were not available for deriving 30-day, 90-day and 2-year PAL 3 values.

  7. Effect of Staining Solutions on Color Stability of Silorane & Methacrylate Restorative Material

    PubMed Central

    S. Madhyastha, Prashanthi; G. Naik, Dilip; Kotian, Ravindra; Srikant, N.; M. R. Bhat, Kumar

    2015-01-01

    Color stability throughout the functional lifetime of restorations is important for the durability of treatment and of cosmetic importance. The purpose of this study was to evaluate the discoloration properties of a silorane-based (Filtek P90) and methacrylate-based (Z100) composites upon exposure to different staining solutions that are used on day to day basis (turmeric, tea, coffee, cocoa, lime, yoghurt and distilled water) for different immersion periods (1, 7, 14 and 28 days). The colors of all specimens before and after storage in the solutions were measured by a reflectance spectrophotometer based on CIE Lab system and the color differences were calculated. Data were statistically analyzed by repeated measures of ANOVA and sidak post hoc test (for immersion period);‘t’ test (for each material) and one way ANOVA (for staining agents). All the staining agents showed significant difference in staining over time in both the materials. However, Z100 showed higher quantum of discoloration at all time periods at each staining agents (p<0.005). In conclusion, the silorane-based resin (Filtek P90) composites exhibited better color stability (less change in ΔE) after exposure to the staining solutions. Among the staining agents cocoa was found to be least staining followed by lime, yoghurt, coffee, tea whereas turmeric discolored the composites to the maximum. Highest discoloration was seen at day 28 in all staining agents. Cocoa and lime discolored to maximum at early stages but remained stable thereafter whereas tea, coffee and turmeric progressively discolored the composite over time.

  8. Technique sensitivity: biological factors contributing to clinical success with various restorative materials.

    PubMed

    Cox, C F; Tarim, B; Kopel, H; Gürel, G; Hafez, A

    2001-08-01

    Since the 1950s, clinicians have relied on various formulations of Ca(OH)2 to stimulate dentin bridge formation. Various studies (Kozlov and Massler, 1966; Massler, 1967; Brännström, 1978; Cox et al., 1987; Snuggs et al., 1993) have demonstrated that pulp healing and dentin bridging can occur against a pH spectrum of materials. Recent studies (Akimoto et al., 1998; Cox et al., 1998, 1999; Tarim et al., 1998; Kitasako et al., 1999; Hafez et al., 2000) have reported successful pulp healing and dentin bridging using adhesives for direct capping of exposed pulps. However, others (Costa et al., 1997; Stanley and Pameijer, 1997; Pameijer, 1998; Hebling et al., 1999; Carvalho et al., 2000) have reported unsatisfactory results when exposures were direct-capped with adhesives. Biological and technical factors, or a combination of both, might be postulated to explain these differences. Recent studies have demonstrated that biological success is dependent upon proper hemorrhage control at the exposure site. This review explores the differences and common factors influencing successful dentin bridging, focusing on data derived from animal studies conducted according to ISO usage guidelines for cavity preparation and material placement. In the past, there has been concern that etching of vital dentin leads to immediate pulp death due to low pH. Recent studies have reported that acidic cements cause breakdown of only the smear layer and fail to seal the restoration interface, leading to inflammation and necrosis. A properly hybridized dentinadhesive interface provides a "bacteriometic" seal to both dentin and pulp tissues. Recent ISO usage studies have shown a high incidence of dentin bridging with adhesives following proper hemorrhage control and removal of both operative debris and biofilm at the dentin-pulp interface by agents such as NaOCl. These are important technique-sensitivity factors to be considered for pulp healing and dentin bridge formation.

  9. Reliability, failure probability, and strength of resin-based materials for CAD/CAM restorations

    PubMed Central

    Lim, Kiatlin; Yap, Adrian U-Jin; Agarwalla, Shruti Vidhawan; Tan, Keson Beng-Choon; Rosa, Vinicius

    2016-01-01

    ABSTRACT Objective: This study investigated the Weibull parameters and 5% fracture probability of direct, indirect composites, and CAD/CAM composites. Material and Methods: Discshaped (12 mm diameter x 1 mm thick) specimens were prepared for a direct composite [Z100 (ZO), 3M-ESPE], an indirect laboratory composite [Ceramage (CM), Shofu], and two CAD/CAM composites [Lava Ultimate (LU), 3M ESPE; Vita Enamic (VE), Vita Zahnfabrik] restorations (n=30 for each group). The specimens were polished, stored in distilled water for 24 hours at 37°C. Weibull parameters (m= modulus of Weibull, σ0= characteristic strength) and flexural strength for 5% fracture probability (σ5%) were determined using a piston-on-three-balls device at 1 MPa/s in distilled water. Statistical analysis for biaxial flexural strength analysis were performed either by both one-way ANOVA and Tukey's post hoc (α=0.05) or by Pearson's correlation test. Results: Ranking of m was: VE (19.5), LU (14.5), CM (11.7), and ZO (9.6). Ranking of σ0 (MPa) was: LU (218.1), ZO (210.4), CM (209.0), and VE (126.5). σ5% (MPa) was 177.9 for LU, 163.2 for CM, 154.7 for Z0, and 108.7 for VE. There was no significant difference in the m for ZO, CM, and LU. VE presented the highest m value and significantly higher than ZO. For σ0 and σ5%, ZO, CM, and LU were similar but higher than VE. Conclusion: The strength characteristics of CAD/ CAM composites vary according to their composition and microstructure. VE presented the lowest strength and highest Weibull modulus among the materials. PMID:27812614

  10. Attitudes of some European dental undergraduate students to the placement of direct restorative materials in posterior teeth.

    PubMed

    Lynch, C D; Guillem, S E; Nagrani, B; Gilmour, A S M; Ericson, D

    2010-12-01

    The aim of this article was to report on the attitudes, opinions and confidences of final year dental students in three European schools towards the restoration of posterior teeth and in particular towards the use of amalgam and resin composite. One hundred and twenty-eight pre-piloted questionnaires were distributed to final year dental students in Cardiff, Dublin and Malmö. The questionnaire sought information relating to various opinions and attitudes towards the use of amalgam and resin composite in posterior teeth. Information was returned anonymously. Ninety-one completed questionnaires were returned (response rate=71%; Cardiff: n =40, Dublin: n=24, Malmö: n=27). Ninety-three per cent of Malmö students (n=24), 67% of Dublin students (n=16) and 60% of Cardiff students (n=24) reported that they feel confident when placing posterior resin composites. One hundred per cent of Malmö students (n=27), 75% of Cardiff students (n=30) and 33% of Dublin students (n=8) would prefer to have a resin composite rather than amalgam, placed in one of their own posterior teeth. Eighty-five per cent of Malmö students (n=23), 30% of Cardiff students (n=12) and 25% of Dublin students (n=6) perceive amalgam as being harmful to the environment. For the restoration of a posterior tooth in a pregnant female, 44% of students (n=40) would place a resin composite restoration, and 7% (n=6) would place an amalgam restoration, while 32% (n=29) would place a temporary restoration. Students at Malmö report that they place more posterior resin composites and have greater confidence at placing posterior resin composites than students at Cardiff or Dublin. There was confusion relating to the choice of restorative materials for pregnant females. Large variations in restorative strategies among graduates must be considered as dental professionals can practice in all countries within the European Union.

  11. Digital approach to planning computer-guided surgery and immediate provisionalization in a partially edentulous patient.

    PubMed

    Arunyanak, Sirikarn P; Harris, Bryan T; Grant, Gerald T; Morton, Dean; Lin, Wei-Shao

    2016-07-01

    This report describes a digital approach for computer-guided surgery and immediate provisionalization in a partially edentulous patient. With diagnostic data obtained from cone-beam computed tomography and intraoral digital diagnostic scans, a digital pathway of virtual diagnostic waxing, a virtual prosthetically driven surgical plan, a computer-aided design and computer-aided manufacturing (CAD/CAM) surgical template, and implant-supported screw-retained interim restorations were realized with various open-architecture CAD/CAM systems. The optional CAD/CAM diagnostic casts with planned implant placement were also additively manufactured to facilitate preoperative inspection of the surgical template and customization of the CAD/CAM-fabricated interim restorations. PMID:26868961

  12. Comparative evaluation of bond strengths of different core materials with various luting agents used for cast crown restorations.

    PubMed

    Nayakar, Ramesh P; Patil, Narendra P; Lekha, K

    2012-09-01

    The coronal cast restoration continues to be used commonly to restore mutilated, endodontically treated teeth. The tensile bond strength of luting cements is of critical importance as many of failures are at the core and the crown interface. An invitro study with aim to evaluate and compare bond strengths of luting cements between different core materials and cast crowns. A total of 45 extracted identical mandibular second premolars were endodontically treated and divided into 3 groups of 15 each. Specimens in first group were restored with cast post and core (Group C), and specimens in second group were restored with stainless steel parapost and composite core material (Group B) and specimens in third group were restored with stainless steel parapost and glass ionomer core build (Group G). Standardized crown preparation was done for all the specimens to receive cast crowns. Each group was further divided into 3 subgroups and were cemented using 3 different luting cements namely, resin cement, polycarboxylate cement, glass ionomer cement (Type I). The samples of each subgroup (n = 5) were subjected to tensile testing using Universal Testing Machine at a crosshead speed of 2 mm/min till the dislodgement of crown from the core surface was observed. The bond strengths were significantly different according one way ANOVA (F-150.76 and p < 0.0000). The results of the study showed that the specimens cemented with resin cement in cast core, composite core and glass ionomer core exhibited significantly higher bond strengths as compared to specimens cemented with glass ionomer and polycarboxylate cement. Composite resin core and resin cement combinations were superior to all other cement and core combinations tested.

  13. Short- and long-term clinical evaluation of post-operative sensitivity of a new resin-based restorative material and self-etching primer.

    PubMed

    Gordan, Valeria V; Mjör, Ivar A

    2002-01-01

    This study evaluated the post-operative sensitivity of posterior restorations restored with a resin-based restorative material and a self-etching primer. Forty-six restorations, 28 Class I and 18 Class II were placed by two clinicians in 25 patients. After cavity preparations were completed under rubber dam isolation, they were restored using a self-etching primer (Fluorobond, Shofu Inc, Kyoto, Japan) and a resin-based restorative material (Beautifil, Shofu Inc, Kyoto, Japan). Patients were contacted on days 2 and 7 post-operatively and questioned regarding the presence of sensitivity, the stimuli that created sensitivity, the length of time the sensitivity lasted and its intensity using a rating scale from slight to severe. If sensitivity was experienced on day 7, patients were also contacted on days 14, 30 and 90 to assess the degree of sensitivity. All patients were recalled after 6-, 12- and 24-months for further evaluation of any sensitivity experienced. Chi-Square and Fisher's Exact Test were used for statistical analysis. At day 2, six restorations were sensitive to cold with no statistical difference (p > 0.05) from the restorations that were not sensitive. At day 7, only two restorations were sensitive. No sensitivity was present after day 14, which was also confirmed at the six-month recall. No correlation could be established among the duration of the sensitivity, the degree of pain and the causes that initiated sensitivity (p > 0.05). At one-year recall, one restoration was replaced due to post-operative sensitivity that started after the six-month recall. No sensitivity was noted at the 24-month recall. No correlation (p > 0.05) was found between sensitive restorations and those with a normal response throughout the study. The study showed that Fluorobond self-etching primer and Beautifil resin-based restorative material, when placed in posterior restorations, do not result in long-term post-operative sensitivity.

  14. Optical properties of dental restorative materials in the wavelength range 400 to 700 nm for the simulation of color perception.

    PubMed

    Friebel, Moritz; Povel, Kirsten; Cappius, Hans-Joachim; Helfmann, Jürgen; Meinke, Martina

    2009-01-01

    Aesthetic restorations require dental restorative materials to have optical properties very similar to those of the teeth. A method is developed to this end to determine the optical parameters absorption coefficient mu(a), scattering coefficient mu(s), anisotropy factor g, and effective scattering coefficient mu(s) (') of dental restorative materials. The method includes sample preparation and measurements of transmittance and reflectance in an integrating sphere spectrometer followed by inverse Monte Carlo simulations. Using this method the intrinsic optical parameters are determined for shade B2 of the light-activated composites TPH((R)) Spectrum, Esthet-X, and the Ormocer Definite in the wavelength range 400 to 700 nm. By using the determined parameters mu(a), mu(s), and g together with an appropriate phase function, the reflectance of samples with 1-mm layer thickness and shade B2 could be predicted with a very high degree of accuracy using a forward Monte Carlo simulation. The color perception was calculated from the simulated reflectance according to the CIELAB system. We initiate the compilation of a data pool of optical parameters that in the future will enable calculation models to be used as a basis for optimization of the optical approximation of the natural tooth, and the composition of new materials and their production process.

  15. Optical properties of dental restorative materials in the wavelength range 400 to 700 nm for the simulation of color perception

    NASA Astrophysics Data System (ADS)

    Friebel, Moritz; Povel, Kirsten; Cappius, Hans-Joachim; Helfmann, Jürgen; Meinke, Martina

    2009-09-01

    Aesthetic restorations require dental restorative materials to have optical properties very similar to those of the teeth. A method is developed to this end to determine the optical parameters absorption coefficient μa, scattering coefficient μs, anisotropy factor g, and effective scattering coefficient μs' of dental restorative materials. The method includes sample preparation and measurements of transmittance and reflectance in an integrating sphere spectrometer followed by inverse Monte Carlo simulations. Using this method the intrinsic optical parameters are determined for shade B2 of the light-activated composites TPH® Spectrum®, Esthet-X®, and the Ormocer® Definite® in the wavelength range 400 to 700 nm. By using the determined parameters μa, μs, and g together with an appropriate phase function, the reflectance of samples with 1-mm layer thickness and shade B2 could be predicted with a very high degree of accuracy using a forward Monte Carlo simulation. The color perception was calculated from the simulated reflectance according to the CIELAB system. We initiate the compilation of a data pool of optical parameters that in the future will enable calculation models to be used as a basis for optimization of the optical approximation of the natural tooth, and the composition of new materials and their production process.

  16. Effects of a paste-free prophylaxis polishing cup and various prophylaxis polishing pastes on tooth enamel and restorative materials.

    PubMed

    Covey, David A; Barnes, Caren; Watanabe, Hidehiko; Johnson, William W

    2011-01-01

    The application of cleaning and polishing agents to a patient's dentition is a routine part of many dental practices. This study measured the surface roughness and surface gloss of tooth enamel, composite resin, and dental porcelain restorative materials when exposed to a paste-free prophylaxis polishing cup as well as a conventional prophylaxis polishing paste. Samples of human tooth enamel, a composite resin restorative material, and dental porcelain were prepared by a series of polishing papers to produce a flat smooth surface. The baseline average surface roughness (Ra) was measured using a contact stylus profilometer, and the surface gloss was measured with a glossmeter. The test samples were subjected to a standardized polishing routine using a paste-free prophylaxis polishing cup and a fine- or coarse-particle prophylaxis paste. Post-treatment surface roughness and gloss measurements were compared using a paired t statistical test. The conventional prophylaxis pastes increased surface roughness and decreased the gloss of the composite resin and tooth enamel test groups. The paste-free cups did not significantly affect the surface roughness of the enamel or the restorative materials. Dental porcelain surface roughness essentially was not affected by the application of paste-free cups and the fine and coarse pastes.

  17. Finite element modeling of dental restoration through multi-material laser densification

    NASA Astrophysics Data System (ADS)

    Dai, Kun

    To provide guidance for intelligent selection of various parameters in the Multi-Material Laser Densification (MMLD) process for dental restorations, finite element modeling (FEM) has been carried out to investigate the MMLD process. These modeling investigations include the thermal analysis of the nominal surface temperature that should be adopted during experiments in order to achieve the desired microstructure; the effects of the volume shrinkage due to transformation from a powder compact to dense liquid on the temperature distribution and the size of the transformation zone; the evolution of transient temperature, transient stresses, residual stresses and distortions; and the effects of laser processing conditions, such as fabrication sequences, laser scanning patterns, component sizes, preheating temperatures, laser scanning rates, initial porosities, and thicknesses of each powder layer, on the final quality of the component fabricated via the MMLD process. The simulation results are compared with the experiments. It is found that the predicted temperature distribution matches the experiments very well. The nominal surface temperature applied on the dental porcelain body should be below 1273 K to prevent the forming of the un-desired microstructure (i.e., a leucite-free glassy phase). The simplified models that do not include the volume shrinkage effect provide good estimations of the temperature field and the size of the laser-densified body, although the shape of the laser-densified body predicted is different from that obtained in the experiment. It is also fount that warping and residual thermal stresses of the laser-densified component are more sensitive to the chamber preheating temperature and the thickness of each powder layer than to the laser scanning rate and the initial porosity of the powder layer. The major mechanism responsible for these phenomena is identified to be related to the change of the temperature gradient induced by these laser

  18. Bacteriology of deep carious lesions underneath amalgam restorations with different pulp-capping materials - an in vivo analysis

    PubMed Central

    NEELAKANTAN, Prasanna; RAO, Chandragiri Venkata Subba; INDRAMOHAN, Jamuna

    2012-01-01

    Microorganisms remaining in dentin following cavity preparation may induce pulp damage, requiring the use of pulp-capping agents with antimicrobial activity underneath permanent restorations. Objective The aims of this study were to analyze the bacteriological status of carious dentin and to assess the efficacy of different base underneath silver amalgam restorations. Material and Methods This study was conducted on 50 patients aged 13 to 30 years. Sterile swabs were used to take samples after cavity preparation, which was assessed by microbiological culture to identify the microorganisms present. Following this, cavities were restored with silver amalgam, using one of the materials being investigated, as the base: calcium hydroxide (Group II), polyantibiotic paste (Group III), a novel light-cured fluoride-releasing hydroxyapatite-based liner (Group IV) and mineral trioxide aggregate - MTA (Group V). In Group I, the cavities were restored with silver amalgam, without any base. After 3 months, the amalgam was removed and samples taken again and analyzed for the microbial flora. Results Lactobacilli were the most commonly isolated microorganisms in the samples of carious dentin. Groups IV and V showed negative culture in the 3-month samples. There was no statistically significant difference between Groups I, II and III. There was no significant difference between Groups IV and V (p>0.05). Both Groups IV and V showed significantly better results when compared to Groups I, II and III (p<0.05). Conclusions The hydroxyapatite-based liner and MTA performed significantly better in terms of antibacterial activity than the other materials. PMID:22666827

  19. A comparison of retentive strength of implant cement depending on various methods of removing provisional cement from implant abutment

    PubMed Central

    Keum, Eun-Cheol

    2013-01-01

    PURPOSE This study evaluated the effectiveness of various methods for removing provisional cement from implant abutments, and what effect these methods have on the retention of prosthesis during the definitive cementation. MATERIALS AND METHODS Forty implant fixture analogues and abutments were embedded in resin blocks. Forty cast crowns were fabricated and divided into 4 groups each containing 10 implants. Group A was cemented directly with the definitive cement (Cem-Implant). The remainder were cemented with provisional cement (Temp-Bond NE), and classified according to the method for cleaning the abutments. Group B used a plastic curette and wet gauze, Group C used a rubber cup and pumice, and Group D used an airborne particle abrasion technique. The abutments were observed using a stereomicroscope after removing the provisional cement. The tensile bond strength was measured after the definitive cementation. Statistical analysis was performed using one-way analysis of variance test (α=.05). RESULTS Group B clearly showed provisional cement remaining, whereas the other groups showed almost no cement. Groups A and B showed a relatively smooth surface. More roughness was observed in Group C, and apparent roughness was noted in Group D. The tensile bond strength tests revealed Group D to have significantly the highest tensile bond strength followed in order by Groups C, A and B. CONCLUSION A plastic curette and wet gauze alone cannot effectively remove the residual provisional cement on the abutment. The definitive retention increased when the abutments were treated with rubber cup/pumice or airborne particle abraded to remove the provisional cement. PMID:24049563

  20. A system for the diagnosis, placement, and prosthetic restoration of root form implants (U.S. Patent #5,769,636).

    PubMed

    Di Sario, Francesco

    2003-03-01

    It is difficult to achieve a high degree of reproducibility when using a diagnostic wax-up as the template for fabrication of a definitive implant restoration. Here a method for implant prosthesis treatment planning is described that allows fabrication of the provisional restoration before surgical placement of the implant. The method involves 6 steps: (1) determining the mesiodistal inclination of the implant, (2) determining the buccolingual dimension of the alveolar ridge, (3) determining the proper position of the implant, (4) fabricating the surgical guide, (5) fabricating the provisional restoration, and (6) performing surgical placement of the implant followed by immediate placement of the provisional restoration.

  1. The effects of ambient temperature and mixing time of glass ionomer cement material on the survival rate of proximal ART restorations in primary molars

    PubMed Central

    Kemoli, Arthur M

    2014-01-01

    Objective: Temperature fluctuations and material mixing times are likely to affect the consistency and integrity of the material mixture, and hence the restoration made out of it. The purpose of the present study was to determine the influence of the ambient temperature and the mixing time of glass ionomer cement (GIC) restorative material on the survival rate of proximal atraumatic restorative treatment (ART) restorations placed in primary molars. Materials and Methods: A total of 804 restorations were placed in the primary molars of 6-8-year-olds using the ART approach. The restorations were then followed for a period of 2 years and evaluated at given intervals. The data collected were analyzed using SPSS computer statistical program, and the results tested and compared using the Chi-square, Kaplan Meier survival analysis and Cox Proportional hazard statistical tests. Results: The cumulative survival rate of the restorations dropped from the initial 94.4% to 30.8% at the end of 2 years. The higher survival rate of the restorations was associated with the experienced operators and assistants when using the rubber dam isolation method. However, there was no statistically significant difference in the survival rate of the restorations when related to the room temperature and the mixing time of the GIC materials used in spite of the variations in the temperature recoded and the methods used in mixing the materials. Conclusion: The ambient temperature and mixing time of GIC did not have a significant effect on the survival of the proximal ART restorations. PMID:24808692

  2. Use of two surface analyzers to evaluate the surface roughness of four esthetic restorative materials after polishing.

    PubMed

    Joniot, Sabine; Salomon, Jean Pierre; Dejou, Jacques; Grégoire, Geneviève

    2006-01-01

    This study had two aims: determine how well four esthetic restorative materials lent themselves to polishing and compare the results obtained using two different techniques for evaluating surface roughness. The four materials used were two composites modified by the addition of resin, Dyract AP (Dentsply) and Dyract Flow (Dentsply); one composite designed for posterior restorations, SureFil (Dentsply) and one universal micromatrix composite, Esthet-X (Dentsply). Five test pieces were made with each product by inserting the material into cylindrical molds and polymerizing it layer by layer. A single operator polished the specimens on the same day using the Enhance system (Dentsply) and two aluminum oxide pastes. The surfaces were studied successively by means of two surface analyzers: a high-resolution optical profilometer (Nanosurf 488, SAS Technology) and a mechanical profilometer (Mitutoyo Surftest-SV 402). These measurements gave the mean roughness of the surface (Ra). Ten zones were examined for each specimen, and the specimens were observed under an optical microscope (PMG3 inverted metallographic microscope) at 50x magnification. The qualitative and quantitative analyses of the results showed good surface states for all materials. However, the composites based on nano- and micro-filler technology gave the smoothest surfaces after polishing. A comparison of the values obtained with each method of observation showed that mechanical profilometry tended to show roughness caused by polishing, while optical profilometry brought out roughness due to the structure of the material itself.

  3. Beneficial use of dredged material for habitat creation, enhancement, and restoration in New York-New Jersey Harbor.

    PubMed

    Yozzo, David J; Wilber, Pace; Will, Robert J

    2004-10-01

    A comprehensive Dredged Material Management Plan (DMMP) has been developed by the US Army Corps of Engineers, New York District (USACE-NYD) and the Port Authority of New York and New Jersey (PANY/NJ). The primary objective of the DMMP is to identify cost-effective and environmentally acceptable alternatives for the placement of dredged material derived from ongoing and proposed navigation improvements within the PANY/NJ. A significant portion of this dredged material is classified as unsuitable for open-ocean disposal. One suite of alternatives presented within the DMMP is the beneficial use of dredged material for habitat creation, enhancement, and restoration within the NY/NJ Harbor Estuary. Proposed beneficial use/habitat development projects include the use of dredged material for construction of artificial reefs, oyster reef restoration, intertidal wetland and mudflat creation, bathymetric recontouring, filling dead-end canals/basins, creation of bird/wildlife islands, and landfill/brownfields reclamation. Preliminary screening of the proposed beneficial use alternatives identified advantages, disadvantages, potential volumes, and estimated costs associated with each project type. Continued study of the proposed beneficial use alternatives has identified areas of environmental research or technology development where further investigation is warranted.

  4. The Market Gate of Miletus: damages, material characteristics and the development of a compatible mortar for restoration

    NASA Astrophysics Data System (ADS)

    Siegesmund, Siegfried; Middendorf, Bernhard

    2008-12-01

    The indoor exhibit of the Market Gate of Miletus is unique for an archaeological monument. The reconstruction of the gate was done in such a way that most marble fragments were removed leaving cored marble columns 3-4 cm in thickness. These cored columns were mounted on a steel construction and filled with different mortars or filled with specially shaped blocks of brick combined with mortar. All the missing marble elements were replaced by copies made of a Portland cement based concrete, which is compositionally similar to the original building materials. During the Second World War the monument was heavily damaged by aerial bombardment. For 2 years the Market Gate of Miletus was exposed to weathering, because a brick wall protecting the gate was also destroyed. The deterioration phenomena observed are microcracks, macroscopic fractures, flaking, sugaring, greying, salt efflorescence, calcitic-sinter layers and iron oxide formation etc. The rapid deterioration seems to be due to indoor atmospheric effects, and also by a combination of incompatible materials (e.g. marble, steel, mortar, concrete, bricks etc.). Compatible building materials like mortars or stone replacing materials have to be developed for the planned restoration. The requirements for restoration mortars are chemical-mineralogical and physical-mechanical compatibilities with the existing building materials. In detail this means that the mortar should ensure good bonding properties, adapted strength development and not stain the marble when in direct contact. The favoured mortar was developed with a hydraulic binder based on iron-free white cement and pozzolana based on activated clay. A special limestone and quartz sand mixture was used as an aggregate. The cement was adjusted using chemical additives. Specially designed tests were applied extensively to prove whether the developed mortar is suitable for the restoration of this precious monument.

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

    PubMed

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

    2010-10-01

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

  6. Development of dental restorative materials based on visible light-cured multi-methacrylates

    NASA Astrophysics Data System (ADS)

    Tiba, Amer

    that the BPA oligomer (multi-methacrylate) based resin significantly favored the cell growth of the human gingival fibroblasts, compared to the control. An experimental composite was made from EPBPA oligomers (multi-methacrylates). The compressive strength of the experimental EPBPA containing composite was not significantly different than the commercial composite Herculite HXR. SEM photomicrographs revealed more voids in the experimental composites than the commercial composite on both the external surfaces of the prepared specimens and the subsequent fractured surfaces. This is due to the molding technique for specimen preparation and lack of good mechanical mixing for filler incorporation prior to placement of the resin in the mold for subsequent photopolymerization. However, the water sorption for the experimental EPBPA-based composite was significantly lower than the commercial Herculite (HXR) composite. This is most likely related to the hydrophobic nature of the experimental resin. These results suggest that the new type of polyfunctional methacrylate oligomers (PEBPA) have potential application in formulating dental composites as direct esthetic restorative materials with improved properties.

  7. Technology and the use of acrylics for provisional dentine protection.

    PubMed

    Kapusevska, Biljana; Dereban, Nikola; Popovska, Mirjana; Nikolovska, Julijana; Radojkova Nikolovska, Vеrа; Zabokova Bilbilova, Efka; Mijoska, Aneta

    2013-01-01

    Acrylics are compounds polymerized from monomers of acrylic, metacrylic acid or acrylonitrates. The purpose of this paper is to present the technology and use of acrylics for provisional dentine protection in the practice of dental prosthodontics. For this reason, we followed 120 clinical cases from the everyday clinical practice, divided into 4 groups of 30 patients who needed prosthetic reconstruction. The first group included cases in which we applied celluloid crowns for dentine protection, for the second group we used acrylic teeth from a set of teeth for complete dentures; in the third and fourth groups the fabrication was done with the system of an impression matrix and the acrylic resin block technique respectively. In all the examined patients, the gingival index by Silness and Loe and the vitality of the dental pulp were verified clinically, after preparation and 8 days from the placement of the provisional crown. The value for dental sensitivity measured after preparation was 2.59, and 8 days after the placement of the provisional crown it bwas 3.1. From these results we can conclude that after the 8th day from the placement of the provisional crown, there was an adaptation period, characterized by a decrease in the painful sensations. The value of the Silness and Loe gingival index measured after the preparation was 1.34, and 8 days from the placement of the provisional crown was 0.94. The results inclined us to the fact that the provisional acrylic crowns facilitated the reparation of the periodontal tissue. PMID:24566021

  8. Finite element analysis of provisional structures of implant-supported complete prostheses.

    PubMed

    Carneiro, Bruno Albuquerque; de Brito, Rui Barbosa; França, Fabiana Mantovani Gomes

    2014-04-01

    The use of provisional resin implant-supported complete dentures is a fast and safe procedure to restore mastication and esthetics of patients soon after surgery and during the adaptation phase to the new denture. This study assessed stress distribution of provisional implant-supported fixed dentures and the all-on-4 concept using self-curing acrylic resin (Tempron) and bis-acrylic resin (Luxatemp) to simulate functional loads through the three-dimensional finite element method. Solidworks software was used to build three-dimensional models using acrylic resin (Tempron, model A) and bis-acrylic resin (Luxatemp, model B) for denture captions. Two loading patterns were applied on each model: (1) right unilateral axial loading of 150 N on the occlusal surfaces of posterior teeth and (2) oblique loading vector of 150 N at 45°. The results showed that higher stress was found on the bone crest below oblique load application with a maximum value of 187.57 MPa on model A and 167.45 MPa on model B. It was concluded that model B improved stress distribution on the denture compared with model A. PMID:24779949

  9. FINITE ELEMENT ANALYSIS OF PROVISIONAL STRUCTURES OF IMPLANT-SUPPORTED COMPLETE PROSTHESES.

    PubMed

    Carneiro, Bruno Albuquerque; Brito Jr, Rui Barbosa; França, Fabiana Mantovani Gomes

    2012-03-01

    Abstract The use of provisional resin implant-supported complete dentures is a fast and safe procedure to restore mastication and aesthetics of patients soon after surgery and during the adaptation phase to the new denture. This study assessed stress distribution of provisional implant-supported fixed dentures and the all-on-four concept using self-curing acrylic resin (Tempron) and bis-acrylic resin (Luxatemp) to simulate functional loads through the 3D finite element method. The Solidworks software was used to build 3D models, using acrylic resin (Tempron - A) and bis-acrylic resin (Luxatemp - B) for denture captions. Two loading patterns were applied on each model: 1) right unilateral axial loading of 150 N on the occlusal surfaces of posterior teeth; 2) oblique loading vector of 150 N at 45 degrees. The results showed that higher stress was found on the bone crest below oblique load application with maximum value of 187.57 MPa on model A and 167.45 MPa on model B. It was concluded that model B improved stress distribution on the denture compared to model A.

  10. Finite element analysis of provisional structures of implant-supported complete prostheses.

    PubMed

    Carneiro, Bruno Albuquerque; de Brito, Rui Barbosa; França, Fabiana Mantovani Gomes

    2014-04-01

    The use of provisional resin implant-supported complete dentures is a fast and safe procedure to restore mastication and esthetics of patients soon after surgery and during the adaptation phase to the new denture. This study assessed stress distribution of provisional implant-supported fixed dentures and the all-on-4 concept using self-curing acrylic resin (Tempron) and bis-acrylic resin (Luxatemp) to simulate functional loads through the three-dimensional finite element method. Solidworks software was used to build three-dimensional models using acrylic resin (Tempron, model A) and bis-acrylic resin (Luxatemp, model B) for denture captions. Two loading patterns were applied on each model: (1) right unilateral axial loading of 150 N on the occlusal surfaces of posterior teeth and (2) oblique loading vector of 150 N at 45°. The results showed that higher stress was found on the bone crest below oblique load application with a maximum value of 187.57 MPa on model A and 167.45 MPa on model B. It was concluded that model B improved stress distribution on the denture compared with model A.

  11. Evaluation of Microleakage of Silorane and Methacrylate Based Composite Materials in Class I Restorations by Using Two Different Bonding Techniques

    PubMed Central

    Alshetili, Mohsen S; Aldeyab, Sultan S

    2015-01-01

    Background: To evaluate the microleakage of silorane-based composite material (Filtek P90) with that of two homologous methacrylate-based composites materials (Filtek Z250 and Filtek Z250 XT), by using two different bonding techniques. Materials and Methods: Sixty extracted human maxillary first premolars prepared for standardized Class I cavities (4 mm × 2 mm × 2 mm) were randomly divided into three groups. Group A (n = 20) was filled with Filtek Z250 (Methacrylate) using single bond universal total etching technique, Group B (n = 20) was filled with Filtek Z250 XT (Methacrylate) using single bond universal self-etching technique and Group C (n = 20) restored with Filtek P90 (Silorane) with dedicated two-step self-etching prime and bond adhesive system (P90 system adhesive). Teeth were subjected to thermocycling regime (500×, 5-55°C), and dye penetration by immersing in 2% methylene blue for 24 h. Tooth sectioning was performed, and extent of the dye penetration was scored based on dye penetration scale to evaluate the microleakage. Statistical analysis included descriptive statistics and inferential statistics of Kruskal–Wallis test to compare the mean ranks between groups. Results: There was no significant difference observed for microleakage among the three composite materials tested in the present study. However, the cavities restored with silorane (Filtek P90) based composite displayed higher microleakage than the Filtek Z250, Z250 XT. Conclusion: All the restorative systems tested in this study exhibited microleakage, but the silorane technology showed more microleakage when compared to the methacrylate-based composite systems. PMID:26668473

  12. Conservative Approach for Restoring Posterior Missing Tooth with Fiber Reinforcement Materials: Four Clinical Reports

    PubMed Central

    Karaarslan, Emine Sirin; Ertas, Ertan; Ozsevik, Semih; Usumez, Aslihan

    2011-01-01

    Adhesively luted, fiber-reinforced, composite-inlay, retained fixed-partial dentures can be a clinical alternative for the replacement of missing posterior teeth in selective situations. This type of restoration allows for satisfactory esthetics and reduced tooth preparation compared to a conventional, fixed-partial denture. This clinical report describes the use of a fiber-reinforced, composite-inlay, retained fixed-partial denture as a conservative alternative for the replacement of missing posterior teeth. PMID:21912503

  13. Biodentine versus Mineral Trioxide Aggregate versus Intermediate Restorative Material for Retrograde Root End Filling: An Invitro Study

    PubMed Central

    Soundappan, Saravanapriyan; Sundaramurthy, Jothi Latha; Raghu, Sandhya; Natanasabapathy, Velmurugan

    2014-01-01

    Objective The aim of this study was to evaluate the marginal adaptation of Biodentine in comparison with Mineral Trioxide Aggregate (MTA) and Intermediate Restorative Material (IRM), as a root end filling material, using Scanning Electron Microscopy (SEM). Materials and Methods: Thirty permanent maxillary central incisors were chemo-mechanically prepared and obturated. Three millimetres of the root end were resected and 3mm retro cavity preparation was done using ultrasonic retrotips. The samples were randomly divided into three groups (n=10) and were restored with root end filling materials: Group I – MTA, Group II – Biodentine, Group III – IRM. The root ends were sectioned transversely at 1mm and 2mm levels and evaluated for marginal adaptation using SEM. The gap between dentin and retro filling material was measured at four quadrants. The mean gap at 1mm level and 2mm level from the resected root tip and combined mean were calculated. The data were statistically analyzed, using one-way ANOVA and Tukey’s HSD post hoc test for intergroup analysis and paired t-test for intragroup analysis. Results: The overall results showed no statistically significant difference between MTA and IRM but both were superior when compared to Biodentine. At 1mm level there was no statistically significant difference among any of the tested materials. At 2mm level MTA was superior to both IRM and Biodentine. Conclusion: In overall comparison, MTA and IRM were significantly superior when compared to Biodentine in terms of marginal adaptation, when used as retrograde filling material. PMID:24910689

  14. Fracture Resistance of Endodontically Treated Maxillary Premolars Restored by Various Direct Filling Materials: An In Vitro Study.

    PubMed

    Mincik, Jozef; Urban, Daniel; Timkova, Silvia; Urban, Renata

    2016-01-01

    The aim of this study is to compare the effect of various restorative materials on fracture resistance in maxillary premolars. Premolars (n = 64) with no restorations or cracks were selected. MOD cavities were prepared considering the buccolingual width to be equal to half of the intercuspal distance. The specimens were randomly divided into 8 groups, 8 specimens each: group A intact teeth, group B unfilled cavity, group C composite made by oblique layering technique, group D composite with 2 mm cusp coverage, group E bulk-filled posterior composite, group F glass-ionomer, group G amalgam, and group H composite with proximal boxes. The specimens were subjected to an axial compression load with the mean values of fracture resistance in group A: 1289 N, group B: 181.75 N, group C: 445.38 N, group D: 645.88 N, group E: 355.13 N, group F: 352.00 N, group G: 191.38 N, and group H: 572.00 N. There was no significant difference between groups B and G, between C and D, E, and F, and between group D and H. All other measurements were statistically significant. We conclude that composite restoration with cusp coverage is the most ideal nonprosthetic solution for endodontically treated teeth. Cusp coverage increases the fracture resistance compared to the conventional cavity design. PMID:27656212

  15. Fracture Resistance of Endodontically Treated Maxillary Premolars Restored by Various Direct Filling Materials: An In Vitro Study

    PubMed Central

    Mincik, Jozef; Timkova, Silvia; Urban, Renata

    2016-01-01

    The aim of this study is to compare the effect of various restorative materials on fracture resistance in maxillary premolars. Premolars (n = 64) with no restorations or cracks were selected. MOD cavities were prepared considering the buccolingual width to be equal to half of the intercuspal distance. The specimens were randomly divided into 8 groups, 8 specimens each: group A intact teeth, group B unfilled cavity, group C composite made by oblique layering technique, group D composite with 2 mm cusp coverage, group E bulk-filled posterior composite, group F glass-ionomer, group G amalgam, and group H composite with proximal boxes. The specimens were subjected to an axial compression load with the mean values of fracture resistance in group A: 1289 N, group B: 181.75 N, group C: 445.38 N, group D: 645.88 N, group E: 355.13 N, group F: 352.00 N, group G: 191.38 N, and group H: 572.00 N. There was no significant difference between groups B and G, between C and D, E, and F, and between group D and H. All other measurements were statistically significant. We conclude that composite restoration with cusp coverage is the most ideal nonprosthetic solution for endodontically treated teeth. Cusp coverage increases the fracture resistance compared to the conventional cavity design. PMID:27656212

  16. Fracture Resistance of Endodontically Treated Maxillary Premolars Restored by Various Direct Filling Materials: An In Vitro Study

    PubMed Central

    Mincik, Jozef; Timkova, Silvia; Urban, Renata

    2016-01-01

    The aim of this study is to compare the effect of various restorative materials on fracture resistance in maxillary premolars. Premolars (n = 64) with no restorations or cracks were selected. MOD cavities were prepared considering the buccolingual width to be equal to half of the intercuspal distance. The specimens were randomly divided into 8 groups, 8 specimens each: group A intact teeth, group B unfilled cavity, group C composite made by oblique layering technique, group D composite with 2 mm cusp coverage, group E bulk-filled posterior composite, group F glass-ionomer, group G amalgam, and group H composite with proximal boxes. The specimens were subjected to an axial compression load with the mean values of fracture resistance in group A: 1289 N, group B: 181.75 N, group C: 445.38 N, group D: 645.88 N, group E: 355.13 N, group F: 352.00 N, group G: 191.38 N, and group H: 572.00 N. There was no significant difference between groups B and G, between C and D, E, and F, and between group D and H. All other measurements were statistically significant. We conclude that composite restoration with cusp coverage is the most ideal nonprosthetic solution for endodontically treated teeth. Cusp coverage increases the fracture resistance compared to the conventional cavity design.

  17. Effects of the Nd:YAG laser on amalgam dental restorative material: a preliminary study

    NASA Astrophysics Data System (ADS)

    Cernavin, Igor; Hogan, Sean P.

    1996-09-01

    The Nd:YAG laser has been marketed as an instrument for use on both hard and soft dental tissues. Its potential for use on hard tissues is limited but it may be the instrument of choice for use in certain soft tissue procedures. The aim of this study was to examine the effects of the Nd:YAG laser on amalgam restorations which frequently occur on tooth surfaces adjacent to areas of soft tissue which may be subjected to the laser. The amalgam used was Tytin. The laser firing was controlled by a computer and a constant repetition rate of 40 Hz was used. Energy per pulse was altered as follows, 30 mJ, 40 mJ, 60 mJ, 80 mJ, 120 mJ and 140 mJ. Exposure times of 0.05 sec, 0.125 sec, 0.25 sec, 0.5 sec, 1 sec, 2 sec, 3 sec, 4 sec, and 5 sec were used. The width of defect was measured using a Nikon measurescope with 10x magnification and it was established that the damage threshold lies between 0.125 sec and 0.25 sec for 30 mJ per pulse. The data was analyzed using a one way ANOVA statistical test. There was a significant correlation between the width of the defect and energy per pulse setting as well as exposure time. The findings indicate that amalgam restorations are prone to damage from inadvertent laser exposure and clinicians must take measures to protect such restorations during lasing of soft tissues.

  18. The effects of the Nd:YAG laser on amalgam dental restorative material.

    PubMed

    Cernavin, I; Hogan, S P

    1999-06-01

    The Nd:YAG laser has been marketed as an instrument for use on both hard and soft dental tissues. Its potential for use on hard tissues is limited but it may be the instrument of choice for use in certain soft tissue procedures. The aim of this study was to examine the effects of the Nd:YAG laser on amalgam restorations which are frequently placed on tooth surfaces adjacent to areas of soft tissue which may be subjected to the laser. The amalgam used was Tytin. The laser firing was controlled by a computer and a constant repetition rate of 40 Hz was used. Energy per pulse was altered as follows: 30 mJ, 40 mJ, 60 mJ, 80 mJ, 120 mJ and 140 mJ. Exposure times of 0.05 s (2 pulses), 0.125 s (5 pulses), 0.25 s (10 pulses), 0.5 s (20 pulses), 1 s (40 pulses), 2 s (80 pulses), 3 s (120 pulses), 4 s (160 pulses), and 5 s (200 pulses) were used. The width of defect was measured using a measuring microscope with 10x magnification and it was established that the damage threshold lies between 0.125 s (5 pulses) and 0.25 s (10 pulses) for 30 mJ per pulse. Scanning electron microscope observations revealed that the melting of amalgam at exposure times of 5 s actually decreased the size of the observed defect. The data were analysed using a two-way ANOVA statistical test. There was a significant (p < 0.001) correlation between the width of the defect and exposure time up to an exposure time of 4 s and the width of defect and the energy per pulse setting. The findings indicate that amalgam restorations are damaged by inadvertent laser exposure and clinicians must take measures to protect such restorations during lasing of soft tissues.

  19. 14 CFR 21.85 - Provisional amendments to type certificates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Provisional amendments to type certificates. (a) An applicant who manufactures aircraft within the United...) An applicant who manufactures aircraft in a foreign country with which the United States has an... airworthiness of the aircraft. (i) The applicant must operate a prototype aircraft modified in accordance...

  20. 14 CFR 21.85 - Provisional amendments to type certificates.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Provisional amendments to type certificates. (a) An applicant who manufactures aircraft within the United... applicant who manufactures aircraft in a foreign country with which the United States has an agreement for... aircraft. (i) The applicant must operate a prototype aircraft modified in accordance with the...

  1. 14 CFR 21.85 - Provisional amendments to type certificates.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Provisional amendments to type certificates. (a) An applicant who manufactures aircraft within the United... applicant who manufactures aircraft in a foreign country with which the United States has an agreement for... aircraft. (i) The applicant must operate a prototype aircraft modified in accordance with the...

  2. 14 CFR 21.85 - Provisional amendments to type certificates.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Provisional amendments to type certificates. (a) An applicant who manufactures aircraft within the United...) An applicant who manufactures aircraft in a foreign country with which the United States has an... airworthiness of the aircraft. (i) The applicant must operate a prototype aircraft modified in accordance...

  3. 14 CFR 21.85 - Provisional amendments to type certificates.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Provisional amendments to type certificates. (a) An applicant who manufactures aircraft within the United... applicant who manufactures aircraft in a foreign country with which the United States has an agreement for... aircraft. (i) The applicant must operate a prototype aircraft modified in accordance with the...

  4. Evaluation of nystatin containing chitosan hydrogels as potential dual action bio-active restorative materials: in vitro approach.

    PubMed

    Perchyonok, V Tamara; Reher, Vanessa; Zhang, Shengmiao; Basson, Nicki; Grobler, Sias

    2014-11-28

    Healing is a specific biological process related to the general phenomenon of growth and tissue regeneration and is a process generally affected by several systemic conditions or as detrimental side-effects of chemotherapy- and radiotherapy-induced inflammation of the oral mucosa. The objectives of this study is to evaluate the novel chitosan based functional drug delivery systems, which can be successfully incorporated into "dual action bioactive restorative materials", capable of inducing in vitro improved wound healing prototype and containing an antibiotic, such as nystatin, krill oil as an antioxidant and hydroxyapatite as a molecular bone scaffold, which is naturally present in bone and is reported to be successfully used in promoting bone integration when implanted as well as promoting healing. The hydrogels were prepared using a protocol as previously reported by us. The physico-chemical features, including surface morphology (SEM), release behaviors, stability of the therapeutic agent-antioxidant-chitosan, were measured and compared to the earlier reported chitosan-antioxidant containing hydrogels. Structural investigations of the reactive surface of the hydrogel are reported. Release of nystatin was investigated for all newly prepared hydrogels. Bio-adhesive studies were performed in order to assess the suitability of these designer materials. Free radical defense capacity of the biomaterials was evaluated using established in vitro model. The bio-adhesive capacity of the materials in the in vitro system was tested and quantified. It was found that the favorable synergistic effect of free radical built-in defense mechanism of the new functional materials increased sustainable bio-adhesion and therefore acted as a functional multi-dimensional restorative material with potential application in wound healing in vitro.

  5. Color change of newly developed esthetic restorative material immersed in food-simulating solutions.

    PubMed

    Fujita, Megumi; Kawakami, Susumu; Noda, Mamoru; Sano, Hidehiko

    2006-06-01

    Recently, an esthetic tooth coating material has been developed. The material consisted of a primer solution, a base coat, and a top coat. The purpose of this study, therefore, was to evaluate the color change of this tooth coating material and two resin composites after immersion in food-simulating, staining solutions. To this end, the newly developed coating material with and without its top coat, a flowable resin composite, and a hybrid resin composite were employed for the evaluation. The specimens were subjected to an experimental 24-hour staining cycle: 7-hour immersion in coffee, green tea or red wine, then 17-hour immersion in artificial saliva solution containing 0.3% mucin. After 24 hours, 3 days, 1, 2, and 4 weeks of immersion, the color changes of all specimen surfaces were measured. Compared with the other materials, the deltaE* value of coating material without its top coat tended to increase as the immersion period increased until 4 weeks. On the other hand, the deltaE* value of coating material with its top coat measured the lowest among the materials tested. Based on the results obtained, it was concluded that when using this recently developed tooth coating material in dental clinics, its top coat should be properly applied.

  6. Quantitative Assessment of Fluoride Release and Recharge Ability of Different Restorative Materials in Different Media: An in Vitro Study

    PubMed Central

    Pathak, Anuradha; Bajwa, Navroop Kaur; Sidhu, Haridarshan Singh

    2014-01-01

    Objective: To measure fluoride release and recharge ability of restorative materials in deionised water, artificial saliva and lactic acid. Materials and Methods: Pellets were prepared from GC2, Ketac N100 and Beautifil II. Each pellets were individually immersed in 10 ml deionised water, artificial saliva or lactic acid as per respective subgroup for 24 h and then elutes were collected. Specimens were reimmersed in respective container. Fluoride released was analysed after 24 h, 7th and 15th day. On 15th day all specimens were exposed to 1.23% APF gel and fluoride release in respective solution was measured on 16th, 22nd, 30th day. Result: Fluoride release was more after 24 h for all materials in all media then decrease gradually. GC2 shows more fluoride release than Ketac N100 at 24 hours and on 7th day but onwards Ketac N100 released significantly more fluoride. Beautifil II showed least fluoride release at all measured intervals in all media. Order of fluoride release in media was lactic acid > deionised water > artificial saliva for all materials. Conclusion: GICs are smart material which release more fluoride when environment become more acidic and also show tendency to recharge which helps clinically in caries risk children. PMID:25654027

  7. Comparative in vitro evaluation of CAD/CAM vs conventional provisional crowns

    PubMed Central

    ABDULLAH, Adil Othman; TSITROU, Effrosyni A; POLLINGTON, Sarah

    2016-01-01

    ABSTRACT Objective This study compared the marginal gap, internal fit, fracture strength, and mode of fracture of CAD/CAM provisional crowns with that of direct provisional crowns. Material and Methods An upper right first premolar phantom tooth was prepared for full ceramic crown following tooth preparation guidelines. The materials tested were: VITA CAD-Temp®, Polyetheretherketone “PEEK”, Telio CAD-Temp, and Protemp™4 (control group). The crowns were divided into four groups (n=10), Group1: VITA CAD-Temp®, Group 2: PEEK, Group 3: Telio CAD-Temp, and Group 4: Protemp™4. Each crown was investigated for marginal and internal fit, fracture strength, and mode of fracture. Statistical analysis was performed using GraphPad Prism software version 6.0. Results The average marginal gap was: VITA CAD-Temp® 60.61 (±9.99) µm, PEEK 46.75 (±8.26) µm, Telio CAD-Temp 56.10 (±5.65) µm, and Protemp™4 193.07(±35.96) µm (P<0.001). The average internal fit was: VITA CAD-Temp® 124.94 (±22.96) µm, PEEK 113.14 (±23.55) µm, Telio CAD-Temp 110.95 (±11.64) µm, and Protemp™4 143.48(±26.74) µm. The average fracture strength was: VITA CAD-Temp® 361.01 (±21.61) N, PEEK 802.23 (±111.29) N, Telio CAD-Temp 719.24 (±95.17) N, and Protemp™4 416.40 (±69.14) N. One-way ANOVA test showed a statistically significant difference for marginal gap, internal gap, and fracture strength between all groups (p<0.001). However, the mode of fracture showed no differences between the groups (p>0.05). Conclusions CAD/CAM fabricated provisional crowns demonstrated superior fit and better strength than direct provisional crowns. PMID:27383707

  8. In vitro comparison of the biocompatibility of mineral trioxide aggregate, 4META/MMA-TBB resin, and intermediate restorative material as root-end-filling materials.

    PubMed

    Yoshimine, Yoshito; Ono, Makiko; Akamine, Akifumi

    2007-09-01

    This study compared the effects of three root-end-filling materials: mineral trioxide aggregate (MTA), 4-META/MMA-TBB resin (Super-bond), and intermediate restorative material (IRM) on osteoblast adhesion, proliferation, and matrix formation. MC3T3-E1 cells were inoculated on set material specimens, and the number of cells adhered to each material was assessed at 6 hours and at 3 days of incubation by using Hoechst 33258 staining under a fluorescence microscope. Furthermore, on day 21 of culture, areas in contact with each material surface were observed at light and electron microscopic levels. Cultured cells that adhered to MTA and Super-bond proliferated significantly between 6 hours and 3 days of culture. In addition, on day 21, they produced a thick matrix layer directly on the material surfaces. In contrast, the number of cells that adhered to IRM significantly decreased with time. These cells appeared round in shape, and no matrix formation was found. These results suggest that MTA and Super-bond have good biocompatibility and allow hard-tissue forming cells to create a matrix layer, which might enhance apical tissue regeneration.

  9. Optimizing the design of bio-inspired functionally graded material (FGM) layer in all-ceramic dental restorations.

    PubMed

    Cui, Chang; Sun, Jian

    2014-01-01

    Due to elastic modulus mismatch between the different layers in all-ceramic dental restorations, high tensile stress concentrates at the interface between the ceramic core and cement. In natural tooth structure, stress concentration is reduced by the functionally graded structure of dentin-enamel junction (DEJ) which interconnects enamel and dentin. Inspired by DEJ, the aim of this study was to explore the optimum design of a bio-inspired functionally graded material (FGM) layer in all-ceramic dental restorations to achieve excellent stress reduction and distribution. Three-dimensional finite element model of a multi-layer structure was developed, which comprised bilayered ceramic, bio-inspired FGM layer, cement, and dentin. Finite element method and first-order optimization technique were used to realize the optimal bio-inspired FGM layer design. The bio-inspired FGM layer significantly reduced stress concentration at the interface between the crown and cement, and stresses were evenly distributed in FGM layer. With the optimal design, an elastic modulus distribution similar to that in DEJ occurred in the FGM layer.

  10. Suspension of bed material over sand bars in the Lower Mississippi River and its implications for Mississippi delta environmental restoration

    NASA Astrophysics Data System (ADS)

    Ramirez, Michael T.; Allison, Mead A.

    2013-06-01

    specific pathways for sand transport in the lower reaches of large rivers, including the Mississippi, is a key for addressing multiple significant geologic problems, such as delta building and discharge to the oceans, and for environmental restoration efforts in deltaic environments threatened by rising sea levels. Field studies were performed in the Mississippi River 75-100 km upstream of the Gulf of Mexico outlet in 2010-2011 to examine sand transport phenomena in the tidally affected river channel over a range of discharges. Methods included mapping bottom morphology (multibeam sonar), cross-sectional and longitudinal measurements of water column velocity and acoustic backscatter, suspended sediment sampling, and channel-bed sampling. Substantial interaction was observed between the flow conditions in the river (boundary shear stress), channel-bed morphology (size and extent of sandy bedforms), and bed material sand transport (quantity, transport mode, and spatial distribution). A lateral shift was observed in the region of maximum bed material transport from deep to shallow areas of subaqueous sand bars with increasing water discharge. Bed material was transported both in traction and in suspension at these water discharges, and we posit that the downriver flux of sand grains is composed of both locally- and drainage basin-sourced material, with distinct transport pathways and relations to flow conditions. We provide suggestions for the optimal design and operation of planned river diversion projects.

  11. Chipping fracture resistance of dental CAD/CAM restorative materials: Part 2. Phenomenological model and the effect of indenter type

    PubMed Central

    Quinn, G.D.; Giuseppetti, A.A.; Hoffman, K.H.

    2014-01-01

    The edge chipping resistances of six CAD/CAM dental restoration materials are analyzed and correlated to other mechanical properties. A new quadratic relationship that is based on a phenomenological model is presented. Objective The purpose of this study was to further analyze the edge chipping resistance of the brittle materials evaluated in Part 1. One objective was to determine why some force-distance trends were linear and others were nonlinear. A second objective was to account for differences in chipping resistance with indenter type. Methods Edge chipping experiments were conducted with different indenters, including some custom-made sharp conical indenters. A new force – distance quadratic expression was correlated to the data and compared to the linear and power law trends. Results The new quadratic function was an excellent fit in every instance. It can account for why some materials can be fit by a linear trend, while others can be fit by the power law trend. The effects of indenter type are accounted for variations in crack initiation and by the wedging stresses once an indentation hole is created. Significance The new quadratic force – edge distance function can be used with edge chipping data for all brittle materials, not just those evaluated in this study. The data trends vary from linear to nonlinear depending upon the material’s hardness, fracture toughness, and elastic modulus. PMID:24685179

  12. Recommendations for conducting controlled clinical studies of dental restorative materials. Science Committee Project 2/98--FDI World Dental Federation study design (Part I) and criteria for evaluation (Part II) of direct and indirect restorations including onlays and partial crowns.

    PubMed

    Hickel, Reinhard; Roulet, Jean-François; Bayne, Stephen; Heintze, Siegward D; Mjör, Ivar A; Peters, Mathilde; Rousson, Valentin; Randall, Ros; Schmalz, Gottfried; Tyas, Martin; Vanherle, Guido

    2007-01-01

    About 35 years ago, Ryge provided a practical approach to the evaluation of the clinical performance of restorative materials. This systematic approach was soon universally accepted. While that methodology has served us well, a large number of scientific methodologies and more detailed questions have arisen that require more rigor. Current restorative materials have vastly improved clinical performance, and any changes over time are not easily detected by the limited sensitivity of the Ryge criteria in short-term clinical investigations. However, the clinical evaluation of restorations not only involves the restorative material per se but also different operative techniques. For instance, a composite resin may show good longevity data when applied in conventional cavities but not in modified operative approaches. Insensitivity, combined with the continually evolving and nonstandard investigator modifications of the categories, scales, and reporting methods, has created a body of literature that is extremely difficult to interpret meaningfully. In many cases, the insensitivity of the original Ryge methods leads to misinterpretation as good clinical performance. While there are many good features of the original system, it is now time to move on to a more contemporary one. The current review approaches this challenge in two ways: (1) a proposal for a modern clinical testing protocol for controlled clinical trials, and (2) an in-depth discussion of relevant clinical evaluation parameters, providing 84 references that are primarily related to issues or problems for clinical research trials. Together, these two parts offer a standard for the clinical testing of restorative materials/procedures and provide significant guidance for research teams in the design and conduct of contemporary clinical trials. Part 1 of the review considers the recruitment of subjects, restorations per subject, clinical events, validity versus bias, legal and regulatory aspects, rationales for

  13. Novel nano-particles as fillers for an experimental resin-based restorative material.

    PubMed

    Rüttermann, S; Wandrey, C; Raab, W H-M; Janda, R

    2008-11-01

    The purpose of this study is to compare the properties of two experimental materials, nano-material (Nano) and Microhybrid, and two trade products, Clearfil AP-X and Filtek Supreme XT. The flexural strength and modulus after 24h water storage and 5000 thermocycles, water sorption, solubility and X-ray opacity were determined according to ISO 4049. The volumetric behavior (DeltaV) after curing and after water storage was investigated with the Archimedes principle. ANOVA was calculated with p<0.05. Clearfil AP-X showed the highest flexural strength (154+/-14 MPa) and flexural modulus (11,600+/-550 MPa) prior to and after thermocycling (117+/-14 MPa and 13,000+/-300 MPa). The flexural strength of all materials decreased after thermocycling, but the flexural modulus decreased only for Filtek Supreme XT. After thermocycling, there were no significant differences in flexural strength and modulus between Filtek Supreme XT, Microhybrid and Nano. Clearfil AP-X had the lowest water sorption (22+/-1.1 microg mm(-3)) and Nano had the highest water sorption (82+/-2.6 microg mm(-3)) and solubility (27+/-2.9 microg mm(-3)) of all the materials. No significant differences occurred between the solubility of Clearfil AP-X, Filtek Supreme XT and Microhybrid. Microhybrid and Nano provided the highest X-ray opacity. Owing to the lower filler content, Nano showed higher shrinkage than the commercial materials. Nano had the highest expansion after water storage. After thermocycling, Nano performed as well as Filtek Supreme XT for flexural strength, even better for X-ray opacity but significantly worse for flexural modulus, water sorption and solubility. The performances of microhybrids were superior to those of the nano-materials. PMID:18635411

  14. Novel nano-particles as fillers for an experimental resin-based restorative material.

    PubMed

    Rüttermann, S; Wandrey, C; Raab, W H-M; Janda, R

    2008-11-01

    The purpose of this study is to compare the properties of two experimental materials, nano-material (Nano) and Microhybrid, and two trade products, Clearfil AP-X and Filtek Supreme XT. The flexural strength and modulus after 24h water storage and 5000 thermocycles, water sorption, solubility and X-ray opacity were determined according to ISO 4049. The volumetric behavior (DeltaV) after curing and after water storage was investigated with the Archimedes principle. ANOVA was calculated with p<0.05. Clearfil AP-X showed the highest flexural strength (154+/-14 MPa) and flexural modulus (11,600+/-550 MPa) prior to and after thermocycling (117+/-14 MPa and 13,000+/-300 MPa). The flexural strength of all materials decreased after thermocycling, but the flexural modulus decreased only for Filtek Supreme XT. After thermocycling, there were no significant differences in flexural strength and modulus between Filtek Supreme XT, Microhybrid and Nano. Clearfil AP-X had the lowest water sorption (22+/-1.1 microg mm(-3)) and Nano had the highest water sorption (82+/-2.6 microg mm(-3)) and solubility (27+/-2.9 microg mm(-3)) of all the materials. No significant differences occurred between the solubility of Clearfil AP-X, Filtek Supreme XT and Microhybrid. Microhybrid and Nano provided the highest X-ray opacity. Owing to the lower filler content, Nano showed higher shrinkage than the commercial materials. Nano had the highest expansion after water storage. After thermocycling, Nano performed as well as Filtek Supreme XT for flexural strength, even better for X-ray opacity but significantly worse for flexural modulus, water sorption and solubility. The performances of microhybrids were superior to those of the nano-materials.

  15. Fluoride release and uptake capacities of fluoride-releasing restorative materials.

    PubMed

    Attar, Nuray; Turgut, Melek D

    2003-01-01

    Many fluoride-releasing dental materials are being sold on the basis of their cariostatic properties. However, the amount fluoride release of these materials is still uncertain. This study investigated the fluoride release and uptake characteristics of four flowable resin composites (Heliomolar Flow, Tetric Flow, Wave, Perma Flo), one flowable compomer (Dyract flow), one conventional glass ionomer cement mixed with two different powder/liquid ratios (ChemFlex Syringeable and ChemFlex Condensable), one packable resin composite (SureFil), one ion-releasing composite (Ariston pHc) and one resin-modified glass ionomer cement (Vitremer). Seven discs (6-mm diameter and 1.5-mm height) were prepared for each material. Each disc was immersed in 3.5 ml of deionized water within a plastic vial and stored at 37 degrees C. The deionized water was changed every 24 hours and the release of fluoride was measured for 30 days. At the end of this period, the samples were recharged with 2 ml of 1.23% acidulated phosphate fluoride (APF) gel for four minutes. Then, all samples were reassessed for an additional 10 days. The fluoride release of all samples was measured with a specific fluoride electrode and an ionanalyzer. Statistical analyses were conducted using two-way repeated measure ANOVA and Duncan's multiple range tests. For all tested materials, the greatest fluoride release was observed after the first day of the study (p<0.01) but gradually diminished with time. During the test period, Tetric Flow released the lowest amount of fluoride; however, no statistically significant difference was found from Wave and Heliomolar Flow (p>0.05). Ariston pHc released the highest amount of fluoride, followed by ChemFlex Syringeable, Vitremer and ChemFlex Condensable. There were statistically significant differences among these materials (p<0.05). Fluoride release of all materials were significantly increased after the first day following refluoridation and Ariston pHc released the greatest

  16. Synthesis and characterizations of a fluoride-releasing dental restorative material.

    PubMed

    Khan, Abdul Samad; Aamer, Sidra; Chaudhry, Aqif Anwar; Wong, Ferranti S L; Ur Rehman, Ihtesham

    2013-08-01

    The aim was to develop an obturating material which has the tendency to release fluoride and minimize interfaces with tooth. Nano-fluorapatite (nFA) powder was synthesized by sol-gel. The composite based on polyurethane (PU) was obtained by chemically binding the nFA (10, 15, 20%wt/wt) to the diisocyanate component by utilizing in-situ polymerization. The procedure involved stepwise addition of monomeric units of PU, and optimizing the reagent concentrations to synthesize composite. The structural, phase and morphological analysis of nFA was evaluated. The structural, fluoride release and in-vitro adhesion analysis with tooth structure of PU/nFA was conducted. For fluoride release analysis the samples were stored in artificial saliva and deionized water for periodical time intervals. Bond strength of composites was analyzed by push-out test. Chemical linkage was achieved between PU and nFA without intermediate coupling agent. The insignificant difference of fluoride release pattern was observed in artificial saliva and (p≥0.05) deionized water. The PU/nFA composite provided sustained release of fluoride over a long period of time. The composite showed more adhesion toward tooth structure with the increase in concentration of nFA. Bond strength of composite was in accordance with root canal filling material, hence, the material with anti-cariogenic properties can be used as an obturating material.

  17. Retentive force of O-ring attachment to use Immediate Provisional Implant (IPI)-retained overdenture.

    PubMed

    Kobayashi, Mariko; Ohkubo, Chikahiro; Suzuki, Yasunori; Aoki, Takayuki; Sato, Jun-ichi; Hosoi, Toshio

    2005-12-01

    This study evaluated the retentive force of the O-ring attachment to an Immediate Provisional Implant (IPI)-retained overdenture. Two sizes of O-rings (#1, #2) were placed on the IPI abutment head. As the controls, soft relining material, silicone lining material, and the PMMA resin were used to connect the IPI abutment head. The retentive forces (n=5, N) obtained at a crosshead speed of 40 mm/min were analyzed by ANOVA/Tukey's HSD test (alpha=0.05). O-ring #1 showed the significantly greatest force among all materials tested (p0.05). Appropriate retention was obtained using the smaller O-ring#1 for the IPI-retained overdenture. PMID:16411569

  18. Influence of different composite materials and cavity preparation designs on the fracture resistance of mesio-occluso-distal inlay restoration.

    PubMed

    Tekçe, Neslihan; Pala, Kansad; Demirci, Mustafa; Tuncer, Safa

    2016-01-01

    The aim of the study to evaluate the fracture resistance of a computer-aided design/computer-aided manufacturing (CAD/CAM) and three indirect composite materials for three different mesio-occluso-distal (MOD) inlay cavity designs. A total of 120 mandibular third molar were divided into three groups: (G1) non-proximal box, (G2) 2-mm proximal box, and (G3) 4-mm proximal box. Each cavity design received four composite materials: Estenia, Epricord (Kuraray, Japan), Tescera (Bisco, USA), and Cerasmart CAD/CAM blocks (GC, USA). The specimens were subjected to a compressive load at a crosshead speed of 1 mm/min. The data was analyzed using the two-way analysis of variance and Bonferroni post hoc test (p<0.05). Estenia exhibited significantly higher fracture strength than Epricord and Cerasmart in G1. In G2 and G3, there was no significant difference among the four materials. Using a non-proximal box design for the cavity can improve the fracture resistance of the inlay restoration.

  19. Restoring marsh elevation in a rapidly subsiding salt marsh by thin-layer deposition of dredged material

    USGS Publications Warehouse

    Ford, M.A.; Cahoon, D.R.; Lynch, J.C.

    1999-01-01

    Thin-layer deposition of dredged material on coastal marsh by means of high-pressure spray dredging (Jet-Spray??2) technology has been proposed as a mechanism to minimize wetland impacts associated with traditional bucket dredging technologies and to restore soil elevations in deteriorated marshes of the Mississippi River delta. The impact of spray dredging on vegetated marsh and adjacent shallow-water habitat (formerly vegetated marsh that deteriorated to open water) was evaluated in a 0.5-ha Spartina alterniflora-dominated salt marsh in coastal Louisiana. The thickness of dredged sediment deposits was determined from artificial soil marker horizons and soil elevation change was determined from sedimentation-erosion tables (SET) established prior to spraying in both sprayed and reference marshes. The vertical accretion and elevation change measurements were made simultaneously to allow for calculation of shallow (~5 m depth) subsidence (accretion minus elevation change). Measurements made immediately following spraying in July 1996 revealed that stems of S. alterniflora were knocked down by the force of the spray and covered with 23 mm of dredged material. Stems of S. alterniflora soon recovered, and by July 1997 the percent cover of S. alterniflora had increased three-fold over pre-project conditions. Thus, the layer of dredged material was thin enough to allow for survival of the S. alterniflora plants, with no subsequent colonization by plant species typical of higher marsh zones. By February 1998, 62 mm of vertical accretion accumulated at this site, and little indication of disturbance was noted. Although not statistically significant, soil elevation change was greater than accretion on average at both the spray and reference marshes, suggesting that subsurface expansion caused by increased root biomass production and/or pore water storage influence elevation in this marsh region. In the adjacent shallow water pond, 129 mm of sediment was deposited in July

  20. Ensuring the global availability of high-quality dental restorative materials.

    PubMed

    Ferracane, J; Fisher, J; Eiselé, J L; Fox, C H

    2013-11-01

    The Minamata Convention, a global legally binding instrument (treaty) on mercury, has been the catalyst for the emerging agenda on global dental materials research. If the current and future challenges of oral health maintenance and healing on a global scale are to be met, a logical and effective research agenda for the discovery and introduction of new, environmentally sustainable, dental materials must be developed through a coordinated effort involving materials scientists, dental clinicians, representatives of industry, members of regional and national regulatory bodies, and advocacy from research organizations. For universal impact, this agenda should be created with awareness of several important ongoing initiatives, such as the WHO non-communicable diseases action plan, the UN sustainable development agenda, and the IADR Global Oral Health In Inequalities Research Agenda (GOHIRA). A significant contributor to this cause is the FDI and its membership, who, through their Vision 2020 initiative, acknowledge their role and responsibility in globally preventing and managing dental disease and providing leadership to the profession in terms of information dissemination and affecting change. Dental researchers also have an obligation to advocate for appropriate funding to match the identified research needs, thus enhancing the possibility that key decision-makers will provide the needed support to achieve the research agenda agreed upon by this diverse group of stakeholders.

  1. RECYCLED WASTE-BASED CEMENT COMPOSITE PATCH MATERIALS FOR RAPID/PERMANENT ROAD RESTORATION.

    SciTech Connect

    SUGAMA,T.

    2001-07-31

    Over the past year, KeySpan Energy sponsored a research program at Brookhaven National Laboratory (BNL) aimed at recycling boiler ash (BA) and waste water treatment sludge (WWTS) byproducts generated from Keyspan's power stations into potentially useful materials, and at reducing concurrent costs for their disposal. Also, KeySpan has an interest in developing strategies to explicitly integrate industrial ecology and green chemistry. From our collaborative efforts with Keyspan (Diane Blankenhom Project Manager, and Kenneth Yager), we succeeded in recycling them into two viable products; Pb-exchange adsorbents (PEAs), and high-performance cements (HpCs). These products were made from chemically bonded cement and ceramic (CBC) materials that were synthesized through two-step chemical reaction pathways, acid-base and hydration. Using this synthesis technology, both the WWTS and BA served in acting as solid base reactants, and sodium polyphosphate, [-(-NaPO{sub 3}-)-{sub n}], known as an intermediator of fertilizer, was employed as the acid solution reactant. In addition, two commercial cement additives, Secar No. 51 calcium aluminate cement (CAC) and Type I calcium silicate cement (CSC), were used to improve mechanical behavior and to promote the rate of acid-base reaction of the CBC materials.

  2. Apical Sealing Ability of Mineral Trioxide Aggregate, Intermediate Restorative Material and Calcium Enriched Mixture Cement: A Bacterial Leakage Study

    PubMed Central

    Shahriari, Shahriar; Faramarzi, Farhad; Alikhani, Mohammad-Yousef; Farhadian, Maryam; Hendi, Seyedeh Sareh

    2016-01-01

    Introduction: This in vitro study compared the apical sealing ability of three common root end filling materials namely mineral trioxide aggregate (MTA), intermediate restorative material (IRM) and calcium-enriched mixture (CEM) cement using a bacterial leakage model. Methods and Materials: The study was conducted on 83 single-rooted human teeth. Tooth crowns were cut and root canals were prepared using the step-back technique. Apical 3 mm of the roots were cut and a three-mm-deep cavity was prepared using an ultrasonic instrument. The samples were divided into three groups (n=25) according to the root-end filling material including MTA, IRM and CEM cement. The roots were inserted into cut-end microtubes. After sterilization with ethylene oxide, microtubes were placed in sterile vials containing 10 mL of Brain Heart Infusion (BHI) broth and incubated at 37°C and 0.1 mL of Enterococcus faecalis suspension compatible with 0.5 McFarland standard (1.5×108 cell/ ml), which was refreshed daily. This procedure was continued for 70 days. The data were analyzed using the chi-square, Kruskal-Wallis and log rank tests. The level of significance was set at 0.05. Results: No significant difference was found in bacterial microleakage among three groups; MTA showed slightly (but not significantly) less microleakage than IRM and CEM. However, the difference in the mean time of microleakage was significant among the groups (P<0.04) and in MTA samples leakage occurred in a longer time than CEM (P<0.012). Conclusion: The three tested root end filling materials had equal sealing efficacy for preventing bacterial leakage. PMID:27790267

  3. The influence of elastic modulus of base material on the marginal adaptation of direct composite restoration.

    PubMed

    Kwon, Oh-Hyun; Kim, Do-Hyun; Park, Sung-Ho

    2010-01-01

    This study compared the marginal adaptation of direct composites under base materials with different elastic moduli. MOD cavities were prepared in 30 teeth. The cervical margin was placed 1 mm above the cementoenamel junction (CEJ) in one side and 1 mm below the CEJ in dentin in the other. The teeth were randomly divided into the following six groups (five teeth each) according to the base materials used: No base (Group 1), experimental flowable composite (Group 2), Helioflow (Ivoclar Vivadent) (Group 3), Tetric Flow (Group 4), Heliomolar HB (Ivoclar Vivadent) (Group 5) and Fuji II LC (Group 6). In Group 1, after etching the cavity enamel with 35% phosphoric acid, the cavities were primed and bonded with AdheSE, then filled with Tetric Ceram according to the manufacturer's instructions. In the other groups, after placing the base materials (1 mm thick) into the cavity, the cavity was filled with Tetric Ceram using the same methods as in Group 1. After storing the specimens in distilled water for seven days, they were finished and polished. Using stereomicroscopy at 150x magnification, marginal adaptation of the specimens was determined and the percentage of the imperfect margin (IM%) in the pre-loaded specimens was calculated. A mechanical load was applied using a custom-made Chewing simulator. All specimens were submitted to 600,000 load cycles at 49N with a frequency of 2Hz. The IM% in the post-load specimens was calculated. Repeated measured one-way ANOVA with Tukey was applied to compare the IM% in the six groups at the 95% confidence level. The results of statistical analysis indicated that the IM% was Group 3, 4, 6 < or = 2 < or = 5 < or = 1.

  4. Photoacoustics study of the degree of polimerization of resins and restoration materials

    NASA Astrophysics Data System (ADS)

    dos Reis Coloiano, Elaine C.; Abrahao Martin, Airton; Dias da Silva, Marcos; Roxo Barja, Paulo; Acosta-Avalos, Daniel

    2003-06-01

    In this work is presented the use of Photoacoustic as an alternative technique to monitor the curing process of odontological materials, emphasizing the resins chemically activated (RCA). Through photoacoustic measurements, it is possible to study optical and thermal properties of samples, and to obtain information on the characteristic times involved in the curing processes. For this study the samples were analyzed to evaluate the polymerization of the RCA for different temperature. The results obtained show the viability of applying the Photoacoustic Techinques to monitor the polyermization kinetic of odontological resins, allowing for a qualitative and quantitative interpretation.

  5. Identification through X-ray fluorescence analysis of dental restorative resin materials: a comprehensive study of noncremated, cremated, and processed-cremated individuals.

    PubMed

    Bush, Mary A; Miller, Raymond G; Prutsman-Pfeiffer, Jennifer; Bush, Peter J

    2007-01-01

    Tooth-colored restorative materials are increasingly being placed in the practice of modern dentistry, replacing traditional materials such as amalgam. Many restorative resins have distinct elemental compositions that allow identification of brand. Not only are resins classifiable by elemental content, but they also survive extreme conditions such as cremation. This is of significance to the forensic odontologist because resin uniqueness adds another level of certainty in victim identification, especially when traditional means are exhausted. In this three-part study, unique combinations of resins were placed in six human cadavers (total 70 restorations). Simulated ante-mortem dental records were created. In a blind experiment, a portable X-ray fluorescence (XRF) unit was used to locate and identify the resin brands placed in the dentition. The technique was successful in location and brand identification of 53 of the restorations, which was sufficient to enable positive victim identification among the study group. This part of the experiment demonstrated the utility of portable XRF in detection and analysis of restorative materials for victim identification in field or morgue settings. Identification of individuals after cremation is a more difficult task, as the dentition is altered by shrinkage and fragmentation, and may not be comparable with a dental chart. Identification of processed cremains is a much greater challenge, as comminution obliterates all structural relationships. Under both circumstances, it is the nonbiological artifacts that aid in identification. Restorative resin fillings can survive these conditions, and can still be named by brand utilizing elemental analysis. In a continuation of the study, the cadavers were cremated in a cremation retort under standard mortuary conditions. XRF was again used to analyze retrieved resins and to identify the individuals based on restorative materials known to exist from dental records. The cremains were

  6. Identification through X-ray fluorescence analysis of dental restorative resin materials: a comprehensive study of noncremated, cremated, and processed-cremated individuals.

    PubMed

    Bush, Mary A; Miller, Raymond G; Prutsman-Pfeiffer, Jennifer; Bush, Peter J

    2007-01-01

    Tooth-colored restorative materials are increasingly being placed in the practice of modern dentistry, replacing traditional materials such as amalgam. Many restorative resins have distinct elemental compositions that allow identification of brand. Not only are resins classifiable by elemental content, but they also survive extreme conditions such as cremation. This is of significance to the forensic odontologist because resin uniqueness adds another level of certainty in victim identification, especially when traditional means are exhausted. In this three-part study, unique combinations of resins were placed in six human cadavers (total 70 restorations). Simulated ante-mortem dental records were created. In a blind experiment, a portable X-ray fluorescence (XRF) unit was used to locate and identify the resin brands placed in the dentition. The technique was successful in location and brand identification of 53 of the restorations, which was sufficient to enable positive victim identification among the study group. This part of the experiment demonstrated the utility of portable XRF in detection and analysis of restorative materials for victim identification in field or morgue settings. Identification of individuals after cremation is a more difficult task, as the dentition is altered by shrinkage and fragmentation, and may not be comparable with a dental chart. Identification of processed cremains is a much greater challenge, as comminution obliterates all structural relationships. Under both circumstances, it is the nonbiological artifacts that aid in identification. Restorative resin fillings can survive these conditions, and can still be named by brand utilizing elemental analysis. In a continuation of the study, the cadavers were cremated in a cremation retort under standard mortuary conditions. XRF was again used to analyze retrieved resins and to identify the individuals based on restorative materials known to exist from dental records. The cremains were

  7. Effect of five commercial mouth rinses on the microhardness of a nanofilled resin composite restorative material: An in vitro study

    PubMed Central

    Jyothi, KN; Crasta, Shanol; Venugopal, P

    2012-01-01

    Aim and Objectives: This in vitro study was designed to comparatively evaluate the effect of five commercial mouth rinses on the micro hardness of a nanofilled resin based restorative material. Materials and Methods: Fifty specimens of resin composite material (Filtek Z350XT, 3M ESPE, St.Paul, MN USA) were prepared and immersed in artificial saliva for 24 h. The base line micro hardness of specimens was recorded using Vicker's micro hardness tester (MMT – X7 Matsuzawa, Japan). The specimens were randomly distributed into five groups, each containing 10 specimens (n=10) as follows – Group I Listerine (alcohol based), Group II Periogard (alcohol based), Group III Colgate plax (alcohol based), Group IV C- prev (alcohol free), Group V Hiora(alcohol free). The specimens were immersed in 20 ml of mouth rinses and incubated for 24 h at 37°C. The post immersion micro hardness values of the specimens were recorded and the data was tabulated for statistical analysis. Kruskal–Wallis test was used for inter group comparison followed by pair wise comparison of groups using Mann–Whitney U test. The level of significance was set at P=0.05. Results: Significant reduction in the mean VHN (Vicker's micro hardness number) was observed in all the groups after exposure to the tested mouth rinses (P<0.01) and the reduction in mean VHN values were as follows: Group I 12.09, Group II 3.42, Group II 1.51, Group IV 1.03, Group V 0.57. Inter group comparison showed statistically significant reduction in micro hardness in Groups I and II compared to all other groups with P<0.001. There was no significant difference between Groups III, IV and V. Conclusion: All the mouth rinses showed a reduction in the microhardness of nanofilled resin composite material with listerine (Group I) containing maximum amount of alcohol, showing highest reduction in micro hardness value. PMID:22876004

  8. Reactions of connective tissue to amalgam, intermediate restorative material, mineral trioxide aggregate, and mineral trioxide aggregate mixed with chlorhexidine.

    PubMed

    Sumer, Mahmut; Muglali, Mehtap; Bodrumlu, Emre; Guvenc, Tolga

    2006-11-01

    The aim of this study was to histopathologically examine the biocompatibility of the high-copper amalgam, intermediate restorative material (IRM), mineral trioxide aggregate (MTA), and MTA mixed with chlorhexidine (CHX). This study was conducted to observe the rat subcutaneous connective tissue reaction to the implanted tubes filled with amalgam, IRM, MTA, and MTA mixed with CHX. The animals were sacrificed 15, 30, and 60 days after the implantation procedure. The implant sites were excised and prepared for histological evaluation. Sections of 5 to 6 microm thickness were cut by a microtome and stained with hemotoxylin eosin and examined under a light microscope. The inflammatory reactions were categorized as weak (none or few inflammatory cells < or =25 cells), moderate (>25 cells), and severe (a lot of inflammatory cells not to be counted, giant cells, and granulation tissue). Thickness of fibrous capsules measured five different areas by the digital imaging and the mean values were scored. Amalgam, IRM, and MTA mixed with CHX caused a weak inflammatory response on days 15, 30, and 60. MTA provoked an initial severe inflammatory response that subsided at the 30 and 60 day study period. A clear fibrous capsule was observed beginning from the 15 days in all of the groups. Within the limits of this study, amalgam, IRM, MTA, and MTA mixed with CHX materials were surrounded by fibrous connective tissue indicated that they were well tolerated by the tissues, therefore, MTA/CHX seemed to be biocompatible.

  9. Effects of Protective Resin Coating on the Surface Roughness and Color Stability of Resin-Based Restorative Materials

    PubMed Central

    Tüzüner, Tamer; Korkmaz, Fatih Mehmet; Baygın, Özgül; Bağış, Yıldırım Hakan

    2014-01-01

    The aim of this study was to evaluate the effects of nanofilled protective resin coating (RC) on the surface roughness (Ra) and color stability (ΔE) of resin-based restorative materials (RM) (compomer (C), nanofilled composite (NF), and microhybrid composite (MH)) after being submitted to the ultraviolet aging (UV) method. Thirty-six specimens were prepared (n = 6 for each group). The Ra and (ΔE) values and SEM images were obtained before and after UV. Significant interactions were found among the RM-RC-UV procedures for Ra (P < 0.001). After the specimens were submitted to UV, the Ra values were significantly increased, regardless of the RC procedure (with RC; P < 0.01 for all, without RC; C (P < 0.01), NF (P < 0.001), and MH (P < 0.001)) for each RM. Significant interactions were found between the RM-RC (P < 0.001) procedures for the ΔE values. The ΔE values were increased in each group after applying the RC procedures (P < 0.001). Protective RC usage for RM could result in material-related differences in Ra and ΔE as with used UV method. PMID:25162066

  10. In vitro evaluation of the effect of two finishing and polishing systems on four esthetic restorative materials

    PubMed Central

    Rai, Rochna; Gupta, Ruchi

    2013-01-01

    Aim: To determine the surface roughness of esthetic restorative materials after finishing and polishing. Materials and Methods: All 60 specimens were divided into four groups. Group I: Nanocomposite, Z 350 XT (3M ESPE, USA); Group II: Microhybrid composite, Z 250 (3M ESPE, USA); Group III: Compomer, Dyract XP (LD Caulk/Dentsply, USA); and Group IV: Resin modified glass ionomer cement (GIC), Fuji II LC (GC, Japan). Each group was again divided into three subgroups. Subgroup A: Sof-Lex (3M ESPE); Subgroup B: Super-Snap Rainbow finishing and polishing kit (Shofu INC, Japan); and Subgroup C: Control Mylar strip. Surface roughness was determined by Perthen Perthometer S6P profilometer. Result: Filtek Z350 XT showed minimum surface roughness followed by Filtek Z250, Dyract XT and Fuji II LC. Super-Snap exhibited less surface roughness than Sof-Lex polishing systems. Statistical Analysis: One-way analysis of variance (ANOVA) followed by multiple post hoc comparisons using least square difference method and unpaired t-test was used. Conclusion: Filtek Z350 XT with Mylar strip exhibited least surface roughness. PMID:24347895

  11. Restoring the worn dentition.

    PubMed

    Ibsen, R L; Ouellet, D F

    1992-01-01

    Strong dental materials and dental porcelains are providing dentists with restorative opportunities that are more conservative because they require less destruction of healthy tooth structure and yield a more esthetic result. In cases of severe wear due to attrition, abrasion, and erosion, this process can be stopped, restoring the esthetics and function by using proper techniques and materials. The case report described in this article demonstrates the conservative restoration of severe wear due to attrition and erosion. Teeth were lengthened, wear was restored, and further wear was ceased by using a combination of bonded porcelain, a heat, light, and self-cure resin system, and a new glass-ionomer restorative material. The result was a strong, durable restoration (that required no anesthesia) with high esthetics.

  12. Provisional Recommended Weight Limits for Manual Lifting During Pregnancy

    PubMed Central

    Waters, Thomas R.; MacDonald, Leslie A.; Hudock, Stephen D.; Goddard, Donald E.

    2015-01-01

    Objective The National Institute for Occupational Safety and Health (NIOSH) Revised Lifting Equation (RNLE) was adapted to derive recommended weight limits (RWLs) for pregnant workers and to develop corresponding guidelines for clinicians. Background In the past three decades there has been a large increase in the number of women employed outside the home and remaining in the workforce during pregnancy. Practical authoritative guidelines based on accumulated evidence are needed to inform allowable work activity levels for healthy pregnant workers. Method Empirically based lifting criteria established by NIOSH to reduce the risk of overexertion injuries in the general U.S. working population were evaluated for application to pregnant workers. Our evaluation included an extensive review of the literature linking occupational lifting to maternal and fetal health. Decision logic and supporting literature are presented, along with computational details. Results Provisional RWLs for pregnant workers were derived from the RNLE, along with guidelines for clinicians. The guidelines advise against pregnant workers lifting below midshin and overhead. Conclusion Based on our review of the available evidence, we present lifting thresholds that most pregnant workers with uncomplicated pregnancies should be able to perform without increased risk of adverse maternal and fetal health consequences. Except for restrictions involving lifting from the floor and overhead, the provisional guidelines presented are compatible with NIOSH lifting recommendations adopted in the early 1990s for the general working population. Application Implementation of these provisional guidelines could protect millions of female workers in the work-place from fetal and maternal lifting-related health problems. PMID:24669554

  13. Proposed framework for cleanup and site restoration following a terrorist incident involving radioactive material.

    PubMed

    Conklin, W Craig

    2005-11-01

    Cleanup following a terrorism incident involving a radiological dispersal device (RDD) or improvised nuclear device (IND) is likely to be technically challenging, costly, and politically charged. Lessons learned from the Top Officials 2 exercise and the increased threat of terrorist use of an RDD or IND have driven federal officials to push for an agreed-upon process for determining appropriate cleanup levels. State and local authorities generally have the ultimate responsibility for final public health decisions in their jurisdictions. In response to terrorist attacks, local authorities are likely to request federal assistance in assessing the risk and establishing appropriate cleanup levels. It is realistic to expect local and state requests for significant federal assistance in planning and implementing recovery operations. State and local authorities may desire "shared accountability" with the federal government in setting the appropriate cleanup levels. Government officials at all levels will face pressure to say how clean is clean enough and how quickly people can re-enter affected areas. Issues arising include (1) the nature of the relationship between the federal, state, and local leadership involved in the recovery efforts and (2) where the funding for recovery comes from. Many agencies, including the U.S. Environmental Protection Agency (EPA), the U.S. Nuclear Regulatory Commission (NRC), and the U.S. Department of Energy (DOE) have long been involved in cleanup activities involving radioactive materials. These agencies have recognized the need for a participatory process and realize the need to remain flexible when faced with possible unprecedented environmental challenges following a terrorist attack. Currently, the Department of Homeland Security has a committee process underway, with participation of the EPA, NRC, DOE, and other federal agencies, to try to resolve these issues and to begin engaging state, local, and tribal governments, and others as

  14. Provisional Crown Dislodgement during Scuba Diving: A Case of Barotrauma

    PubMed Central

    Gulve, Meenal Nitin; Gulve, Nitin Dilip

    2013-01-01

    Changes in ambient pressure, for example, during flying, diving, or hyperbaric oxygen therapy, can lead to barotrauma. Although it may seem that this issue was neglected in dental education and research in recent decades, familiarity with and understanding of these facts may be of importance for dental practitioners. We report the case of a patient who experienced barotrauma involving dislodgement of a provisional crown during scuba diving. Patients who are exposed to pressure changes as a part of their jobs or hobbies and their dentists should know the causes of barotrauma. In addition, the clinician must be aware of the possible influence of pressure changes on the retention of dental components. PMID:23984113

  15. Provisional Crown Dislodgement during Scuba Diving: A Case of Barotrauma.

    PubMed

    Gulve, Meenal Nitin; Gulve, Nitin Dilip

    2013-01-01

    Changes in ambient pressure, for example, during flying, diving, or hyperbaric oxygen therapy, can lead to barotrauma. Although it may seem that this issue was neglected in dental education and research in recent decades, familiarity with and understanding of these facts may be of importance for dental practitioners. We report the case of a patient who experienced barotrauma involving dislodgement of a provisional crown during scuba diving. Patients who are exposed to pressure changes as a part of their jobs or hobbies and their dentists should know the causes of barotrauma. In addition, the clinician must be aware of the possible influence of pressure changes on the retention of dental components. PMID:23984113

  16. Provisional Crown Dislodgement during Scuba Diving: A Case of Barotrauma.

    PubMed

    Gulve, Meenal Nitin; Gulve, Nitin Dilip

    2013-01-01

    Changes in ambient pressure, for example, during flying, diving, or hyperbaric oxygen therapy, can lead to barotrauma. Although it may seem that this issue was neglected in dental education and research in recent decades, familiarity with and understanding of these facts may be of importance for dental practitioners. We report the case of a patient who experienced barotrauma involving dislodgement of a provisional crown during scuba diving. Patients who are exposed to pressure changes as a part of their jobs or hobbies and their dentists should know the causes of barotrauma. In addition, the clinician must be aware of the possible influence of pressure changes on the retention of dental components.

  17. Results of the first provisional technical secretariat interlaboratory comparison test

    SciTech Connect

    Stuff, J.R.; Hoffland, L.

    1995-06-01

    The principal task of this laboratory in the first Provisional Technical Secretariat (PTS) Interlaboratory Comparison Test was to verify and test the extraction and preparation procedures outlined in the Recommended Operating Procedures for Sampling and Analysis in the Verification of Chemical Disarmament in addition to our laboratory extraction methods and our laboratory analysis methods. Sample preparation began on 16 May 1994 and analysis was completed on 12 June 1994. The analytical methods used included NMR ({sup 1}H and {sup 31}P) GC/AED, GC/MS (EI and methane CI), GC/IRD, HPLC/IC, HPLC/TSP/MS, MS/MS(Electrospray), and CZE.

  18. Effect of water temperature on the fit of provisional crown margins during polymerization: An in vitro study

    PubMed Central

    Ramkumar, Vivekanandan; Sangeetha, Arunachalam; Kumar, Vinaya

    2012-01-01

    Aim: To evaluate the effect of water temperature on the marginal fit of bis-acrylic composite provisional crown during resin polymerization. Materials and Methods: Precisely machined 10 brass master dies were designed to simulate molar teeth. Five brass dies were selected and precisely machined to simulate all ceramic crown preparation. An acrylic jaw replica was made in which brass dies were arranged equidistant from each other. A custom-made metallic tray was fabricated on the acrylic jaw replica to make polyvinyl siloxane impression matrix. Bis-acrylic composite resin provisional crowns were made using polyvinyl siloxane impression matrix. Provisional crowns were polymerized at room temperature (Group I direct technique, on dental stone cast; Group I indirect technique crowns) and at different water temperatures (Group II direct technique crowns). The vertical marginal gap between all the provisional crown margins and the finish line of brass dies was measured using a Research Stereomicroscope System. Results: The results were statistically analyzed using one-way analysis of variance (ANOVA) test and Newman–Keul's test. The results showed that crowns polymerized in 20°C and 30°C water had marginal gap approximately three times smaller than those polymerized in 30°C air, due to the reduced polymerization shrinkage. Conclusion: This study shows that crowns polymerized in 20°C and 30°C water had mean vertical marginal gap approximately three times smaller than those polymerized in 30°C air. It was approximately closer to that of crowns fabricated by indirect technique. Warmer water also supposedly hastens polymerization. PMID:23066294

  19. Machining accuracy of crowns by CAD/CAM system using TCP/IP: influence of restorative material and scanning condition.

    PubMed

    Tomita, Sachiko; Shin-ya, Akiyoshi; Gomi, Harunori; Shin-ya, Akikazu; Yokoyama, Daiichiro

    2007-07-01

    The purpose of this study was to determine the optimal condition for fabricating accurate crowns efficiently using an internet-based CAD/CAM system. The influences of three different CAD/CAM restorative materials (titanium, porcelain, and composite resin) and three different step-over scanning distances (0.01 mm, 0.11 mm, and 0.21 mm) were evaluated, and their interactive effects were carefully examined. Several points on the inner and outer surfaces of machined crowns - as well as height - were measured. These measurements were then compared with the original models, from which machining accuracy was obtained. At all measuring points, the inner surface of all crowns was machined larger than the die model, whereas the cervical area of porcelain crown was machined smaller than the crown model. Results of this study revealed that a step-over distance of 0.11 mm was an optimal scanning condition, taking into consideration the interactive effects of scanning time required, data volume, and machining accuracy.

  20. Practitioner, patient, and caries lesion characteristics associated with type of material used to restore carious teeth: findings from The Dental PBRN

    PubMed Central

    Makhija, Sonia K; Gordan, Valeria V.; Gilbert, Gregg H.; Litaker, Mark S.; Rindal, D. Brad; Pihlstrom, Daniel J.; Qvist, Vibeke

    2011-01-01

    Background The authors conducted a study to identify factors associated with material use by dentists in The Dental Practice-Based Research Network (DPBRN) when placing the first restoration on permanent tooth surfaces. Methods A total of 182 DPBRN practitioner-investigators provided data on 5,599 posterior teeth with caries. Practitioner-investigators completed an enrollment questionnaire that included the dentist’s age, gender, practice workload, practice type, and years since graduation. When a consented patient presented with a previously un-restored carious surface, practitioner-investigators recorded patient and tooth characteristics. Results Amalgam was used more often than direct resin-based composite (RBC) for posterior carious lesions. Practitioner/practice characteristics (years since graduation and type of practice); patient characteristics (gender, race, age, and dental insurance); and lesion characteristics (tooth location and surface, pre-and post-operative depth) were associated with the type of restorative material used. Conclusions There are several practitioner/practice, patient, and lesion characteristics significantly associated with use of amalgam and RBC: region, years since graduation, dental insurance, tooth location and surface, and pre-and post-operative depth. Clinical implications Amalgam remains a material commonly used by United States dentists to restore posterior caries lesions. PMID:21628683

  1. Retention and leakage of implant-supported restorations luted with provisional cement: a pilot study.

    PubMed

    Pan, Y-H; Ramp, L C; Lin, C-K; Liu, P-R

    2007-03-01

    Few data exist regarding cement failure load and marginal leakage of castings cemented to implant-supported abutments subjected to load and thermal cycling, especially with newer cements. This study evaluated the cement failure load and marginal leakage of castings cemented to Steri-Oss abutment/analog assemblies with one of seven luting protocols (n = 5). Protocols consisted of a zinc phosphate control, zinc phosphate with petroleum jelly, TempBond, TempBond NE, ImProv, ImProv with petroleum jelly and Provilink. Cemented castings were subjected to cyclic axial compression of 75 N for 100,000 cycles, 1000 thermal cycles (5-55 degrees C), and immersed 24 h in 0.5% basic fuchsin. The castings were then loaded in tension until cement failure. Cement failure load was analysed using anova and Fischer's PLSD (alpha = 0.05). Marginal leakage on the intaglio of the casting was scored with the unaided eye on a scale of 0-2, and analysed with Duncan's multiple range (alpha = 0.05). Similar groups are noted by superscript. Cement failure load (from lowest to highest): ImProv with petroleum jelly(a), TempBond(a), ImProv(a), Tempbond NE(a), Provilink(a), zinc phosphate with petroleum jelly(b), zinc phosphate(c) (P < 0.0001). Marginal leakage scores (from lowest to highest): ImProv(a), Provilink(a), ImProv with petroleum jelly(a), zinc phosphate(ab), zinc phosphate with petroleum jelly(ab), TempBond(bc), and TempBond NE(c) (P = 0.01). Addition of petroleum jelly to zinc phosphate lowered cement failure load without affecting marginal leakage. ImProv and Provilink demonstrated relatively low cement failure load, as well as lowest marginal leakage.

  2. Comparative evaluation of microleakage in Class II restorations using open vs. closed centripetal build-up techniques with different lining materials

    PubMed Central

    Sawani, Shefali; Arora, Vipin; Jaiswal, Shikha; Nikhil, Vineeta

    2014-01-01

    Background: Evaluation of microleakage is important for assessing the success of new restorative materials and methods. Aim and Objectives: Comparative evaluation of microleakage in Class II restorations using open vs. closed centripetal build-up techniques with different lining materials. Materials and Methods: Standardized mesi-occlusal (MO) and distoocclusal (DO) Class II tooth preparations were preparedon 53 molars and samples were randomly divided into six experimental groups and one control group for restorations. Group 1: Open-Sandwich technique (OST) with flowable composite at the gingival seat. Group 2: OST with resin-modified glass ionomer cement (RMGIC) at the gingival seat. Group 3: Closed-Sandwich technique (CST) with flowable composite at the pulpal floor and axial wall. Group 4: CST with RMGIC at the pulpal floor and axial wall. Group 5: OST with flowable composite at the pulpal floor, axial wall, and gingival seat. Group 6: OST with RMGIC at the pulpal floor, axial wall, and gingival seat. Group 7: Control — no lining material, centripetal technique only. After restorations and thermocycling, apices were sealed and samples were immersed in 0.5% basic fuchsin dye. Sectioning was followed by stereomicroscopic evaluation. Results: Results were analyzed using Post Hoc Bonferroni test (statistics is not a form of tabulation). Cervical scores of control were more than the exprimental groups (P < 0.05). Less microleakage was observed in CST than OST in all experimental groups (P < 0.05). However, insignificant differences were observed among occlusal scores of different groups (P > 0.05). Conclusion: Class II composite restorations with centripetal build-up alone or when placed with CST reduces the cervical microleakage when compared to OST. PMID:25125847

  3. Combined amalgam and composite restorations.

    PubMed

    Abu-Hanna, Amer A; Mjör, Ivar A

    2004-01-01

    All indirect restorative techniques involving cast metals, ceramics or resin-based materials are expensive compared to directly placed restorations. A restorative technique is presented that combines the esthetic properties of directly bonded resin-based composite material and the wide range of indications for dental amalgam in stress-bearing areas.

  4. CAD/CAM-generated high-density polymer restorations for the pretreatment of complex cases: a case report.

    PubMed

    Edelhoff, Daniel; Beuer, Florian; Schweiger, Josef; Brix, Oliver; Stimmelmayr, Michael; Guth, Jan-Frederik

    2012-06-01

    Complex rehabilitations represent a particular challenge for the restorative team, especially if the vertical dimension of occlusion (VDO) needs to be reconstructed or redefined. The use of provisional acrylic or composite materials allows clinicians to evaluate the treatment objective over a certain period of time and therefore generates a high predictability of the definitive rehabilitation in terms of esthetics and function. CAD/CAM technology enables the use of prefabricated polymer materials, which are fabricated under industrial conditions to form a highly homogeneous structure compared with those of direct fabrication. This increases long-term stability, biocompatibility, and resistance to wear. Furthermore, they offer more suitable CAD/CAM processing characteristics and can be used in thinner thicknesses than ceramic restorative materials. Also, based on the improved long-term stability, the transfer into the definitive restoration can be divided into multiple treatment steps. This article presents different clinical cases with minimally invasive indications for CAD/CAM-fabricated temporary restorations for the pretreatment of complex cases. PMID:22532953

  5. Combined therapy for teeth with furcation involvement used as abutments for fixed restorations.

    PubMed

    Hürzeler, M B; Strub, J R

    1990-01-01

    Preprosthodontic and prosthodontic procedures for preparing molars with degree 3 furcation involvement for use as abutments for a fixed prosthesis are described. Periodontal surgery precedes endodontic and restorative pretreatment of the abutments, and the required root resection, root separation, or hemisection is performed. A long-term, provisional resin-veneered metal framework restoration is placed for 9 to 12 months. If neither biological nor technical failure occurs, the final metal ceramic fixed restoration may then be fabricated. PMID:2088385

  6. Provisional Assessment of Recent Studies on Health Effects of Particulate Matter Exposure

    EPA Science Inventory

    This report presents the findings of EPA’s survey and provisional assessment of studies published since the completion of the 2009 PM ISA. EPA has screened and surveyed the recent literature and developed a provisional assessment that places those studies of potentially greatest ...

  7. Provisional Admission Practices: Blending Access and Support to Facilitate Student Success

    ERIC Educational Resources Information Center

    Nichols, Andrew Howard; Clinedinst, Melissa

    2013-01-01

    This report examines provisional admission as an initiative that can expand four-year college access and success for students from economically disadvantaged backgrounds. Provisional admission policies and programs enable students to enroll at an institution under specific conditions. Students are often required to meet certain academic…

  8. 10 CFR 903.21 - Completion of rate development; provisional rates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Completion of rate development; provisional rates. 903.21... Participation in Power and Transmission Rate Adjustments and Extensions for the Alaska, Southeastern, Southwestern, and Western Area Power Administrations § 903.21 Completion of rate development; provisional...

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

    PubMed

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

    2016-03-01

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

  10. Surface topography of composite restorative materials following ultrasonic scaling and its Impact on bacterial plaque accumulation. An in-vitro SEM study

    PubMed Central

    Hossam, A. Eid; Rafi, A. Togoo; Ahmed, A Saleh; Sumanth, Phani CR

    2013-01-01

    Background: This is an in vitro study to investigate the effects of ultrasonic scaling on the surface roughness and quantitative bacterial count on four different types of commonly used composite restorative materials for class V cavities. Materials & Methods: Nanofilled, hybrid, silorane and flowable composites were tested. Forty extracted teeth served as specimen and were divided into 4 groups of 10 specimens, with each group receiving a different treatment and were examined by a Field emission scanning electron microscope. Bacterial suspension was then added to the pellicle-coated specimens, and then bacterial adhesion was analyzed by using image analyzing program. Results: Flowable and silorane-based composites showed considerably smoother surfaces and lesser bacterial count in comparison to other types, proving that bacterial adhesion is directly proportional to surface roughness. Conclusion: The use of ultrasonic scalers affects the surfaces of composite restorative materials. Routine periodontal scaling should be carried out very carefully, and polishing of the scaled surfaces may overcome the alterations in roughness, thus preventing secondary caries, surface staining, plaque accumulation and subsequent periodontal inflammation. How to cite this article: Eid H A, Togoo R A, Saleh A A, Sumanth C R. Surface Topography of Composite Restorative Materials following Ultrasonic Scaling and its Impact on Bacterial Plaque Accumulation. An In-Vitro SEM Study. J Int Oral Health 2013; 5(3):13-19. PMID:24155597

  11. In Vitro Solubility and Wear Rates of Silorane and Dimethacrylate Resin Based Composite Restorative Materials under Different pH Conditions

    PubMed Central

    Soliman, Tarek A; Tubaigy, Khalid M; Raffat, Eman M; Al-Agha, Ebaa I

    2015-01-01

    Background: The purpose of this study was to evaluate the effect of different pH solutions on the solubility and wear resistance of Silorane and dimethacrylate resin based composite restorative materials. Materials and Methods: Two different resin based restorative materials (Filtek Silorane P90 and hybrid composite Z100) were tested. Different pH solutions (2.5 and 5) also were used. A total of 60 samples of each type of selected composite were prepared. Specimens were immersed in each type of pH solutions (2.5 and 5) and distilled water as a control group for 24 h then the specimens was subjected to the required mechanical tests. Results: Significant statistical differences were observed regarding water solubility and wear values in different pH solutions. Filtek Silorane presented the smallest values of water solubility and wear values. Conclusion: Under tested experimental conditions, the pH solutions used in this study showed pronounced effect on water solubility and wear values of both two restorative materials. Finally, within the limitation of this study we recommended to use Filtek Silorane (P90) instead of hybrid (Z100) due to its low solubility values under different pH solutions. PMID:26225097

  12. Comparison of aesthetic posterior restorations.

    PubMed

    Trushkowsky, R D

    1991-09-01

    In the past decade there has been an increased desire by the profession and the public for an aesthetic restoration that will restore a posterior tooth to its original form and function. The currently available aesthetic posterior restoration materials and techniques are porcelain, cast ceramic, direct composite, direct-indirect composite, indirect composite, and CAD-CAM fabrications. The indications and contraindications of these restorative materials and proper diagnosis and case selection are described.

  13. Immediate postextraction implantation with provisionalization of two primary canines and related impacted permanent canines: a case report.

    PubMed

    D'Amato, Salvatore; Redemagni, Marco

    2014-01-01

    This study presents a case of replacing two maxillary primary canines and related impacted permanent canines with two single implants, in conjunction with grafting lost hard tissue. By using immediate postextraction implant placement and provisionalization protocols, the stability of the implant was ensured while bypassing the bony void created by the removal of the primary canines. In this respect, a minimum healing period of 1 year was originally planned to evaluate the gingival esthetics before the final step was carried out. By the time the final restorations were fitted, the graft and tissues were stable. The time involved not only placed biology on the clinician's side, but also helped the patient to spread the cost over time. In modern esthetic dentistry, harmonious results can be achieved relatively quickly when the prerequisites for esthetic success have already been met, but, as this case demonstrates, human biology often requires more time and patience for augmented hard and soft tissues to heal and mature.

  14. Stereotype threat and hazard perception among provisional license drivers.

    PubMed

    Skorich, Daniel P; Webb, Hugh; Stewart, Lisa; Kostyanaya, Maria; Cruwys, Tegan; McNeill, Kathy; Frain, Andrew J; Lim, Li; Jones, Benjamin M; Smyth, Lillian; O'Brien, Kerry J

    2013-05-01

    Stereotype threat refers to the negative impact a stereotype about one's group can have on one's performance in domains relevant to the stereotype. In the current paper, we explore whether the negative stereotype of provisional license drivers (PLDs) might produce stereotype threat in a driving-related hazard perception task. We manipulate threat by asking participants to self-identify as PLDs in a categorization condition, or by reminding PLD participants explicitly of the stereotype of PLDs in an explicit stereotype condition. Results reveal increments in hazard perception in the categorization condition, and decrements in hazard perception in the explicit stereotype condition. Mediation analysis reveals that hazard perception performance is fully mediated by increased effort in the categorization condition and by decreased effort in the explicit stereotype condition. We discuss these findings in terms of their implications for stereotype threat and its mediators, and for public policy that explicitly discriminates between PLDs and other driver groups.

  15. Evaluation of Flexural Strength of Thermocycled Interim Resin Materials Used in Prosthetic Rehabilitation- An In-vitro Study

    PubMed Central

    Kadiyala, Krishna Kishore; Anne, Gopinadh; Anche, Sampath Chowdary; Chiramana, Sandeep; Muvva, Suresh Babu; Zakkula, Srujana; Jyothula, Ravi Rakesh Dev

    2016-01-01

    Introduction Provisional restoration is an analytical component of fixed prosthodontics serving as a ground plan for the design of fixed dental prosthesis. Flexural strength is critical in case of long standing fixed dental prosthesis, to appreciate success of full mouth rehabilitation cases and temporomandibular joint dysfunction therapies. Aim The present study was to evaluate the flexural strength of different provisional restorative resins used for prosthetic rehabilitation. Materials and Methods Forty identical samples (n=10 for each material) measuring 25mm×2mm×2mm according to ADA/ANSI specification no. 27 were fabricated using autopolymerizing Poly Methyl Methacrylate (PMMA) (Group A); heat activated PMMA (Group B); autopolymerizing Bis-GMA composite resin (Group C) and light activated Urethane Dimethacrylate Resin (UDMA) (Group D). For 14 days all these samples were stored in artificial saliva. Ten samples from each material were subjected to thermal cycling for 2500 cycles (5°C to 55°C). Later, a standard three point bending test was conducted on all the specimens with a universal testing machine at a crosshead speed of 0.75mm/min. Statistical analysis used included Kruskal-Wallis and Mann-Whitney U test. Results The mean flexural strength of specimens confirmed higher flexural strength for Group C (102.98 Mpa) followed by Group B (91.86 Mpa), Group A (79.13 Mpa) and Group D (60.01 Mpa). There were significant differences between any two materials tested (p <0.05). Comparison between mean flexural strength values between four groups revealed significant difference between the interim materials (p <0.05). Conclusion The greatest flexural strength was observed for Bis-GMA composite resins followed by heat cure methacrylate resins, autopolymerizing methacrylate resins and was least for light cure resins. While fabricating provisional restorations, these greater values should be considered for better outcome of the treatment. PMID:27790588

  16. Comparison of provisional with final notifiable disease case counts - National Notifiable Diseases Surveillance System, 2009.

    PubMed

    2013-09-13

    States report notifiable disease cases to CDC through the National Notifiable Diseases Surveillance System (NNDSS). This allows CDC to assist with public health action and monitor infectious diseases across jurisdictional boundaries nationwide. The Morbidity and Mortality Weekly Report (MMWR) is used to disseminate these data on infectious disease incidence. The extent to which the weekly notifiable conditions are overreported or underreported can affect public health understanding of changes in the burden, distribution, and trends in disease, which is essential for control of communicable diseases. NNDSS encourages state health departments to notify CDC of a case when initially reported. These cases are included in the weekly provisional counts. The status of reported cases can change after further investigation by the states, resulting in differences between provisional and final counts. Increased knowledge of these differences can help in guiding the use of information from NNDSS. To quantify the extent to which final counts differ from provisional counts of notifiable infectious disease in the United States, CDC analyzed 2009 NNDSS data for 67 conditions. The results of this analysis demonstrate that for five conditions, final case counts were lower than provisional counts, but for 59 conditions, final counts were higher than provisional counts. The median difference between final and provisional counts was 16.7%; differences were ≤20% for 39 diseases but >50% for 12. These differences occur for various diseases and in all states. Provisional case counts should be interpreted with caution and an understanding of the reporting process.

  17. The merits of artificial selection for the development of restoration-ready plant materials of native perennial grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    While seed harvested from remnant stands of grass can be used for restoration in temperate regions, seed recovery in semi-arid and arid environments is often unreliable and of low yield and quality. In addition, ongoing harvest of indigenous populations can be unsustainable, especially for those th...

  18. River restoration

    NASA Astrophysics Data System (ADS)

    Wohl, Ellen; Angermeier, Paul L.; Bledsoe, Brian; Kondolf, G. Mathias; Macdonnell, Larry; Merritt, David M.; Palmer, Margaret A.; Poff, N. Leroy; Tarboton, David

    2005-10-01

    River restoration is at the forefront of applied hydrologic science. However, many river restoration projects are conducted with minimal scientific context. We propose two themes around which a research agenda to advance the scientific basis for river restoration can be built. First, because natural variability is an inherent feature of all river systems, we hypothesize that restoration of process is more likely to succeed than restoration aimed at a fixed end point. Second, because physical, chemical, and biological processes are interconnected in complex ways across watersheds and across timescales, we hypothesize that restoration projects are more likely to be successful in achieving goals if undertaken in the context of entire watersheds. To achieve restoration objectives, the science of river restoration must include (1) an explicit recognition of the known complexities and uncertainties, (2) continued development of a theoretical framework that enables us to identify generalities among river systems and to ask relevant questions, (3) enhancing the science and use of restoration monitoring by measuring the most effective set of variables at the correct scales of measurement, (4) linking science and implementation, and (5) developing methods of restoration that are effective within existing constraints. Key limitations to river restoration include a lack of scientific knowledge of watershed-scale process dynamics, institutional structures that are poorly suited to large-scale adaptive management, and a lack of political support to reestablish delivery of the ecosystem amenities lost through river degradation. This paper outlines an approach for addressing these shortcomings.

  19. PROVISIONAL ADVISORY LEVELS (PALs) FOR HYDROGEN SULFIDE (H2S)

    SciTech Connect

    Marshall, Thomas C; Dorman, David; Gardner, Donald; Adeshina, Femi; Ross, Robert Hord

    2009-01-01

    Application of PAL protocols was performed for hydrogen sulfide (H2S) as experimental data permitted. The data base includes human experimental studies, worker exposure evaluations, as well as case studies on acute and repeated exposure. The data base of animal studies is substantial covering multiple species and addressing acute, repeated, and subchronic exposure scenarios. PAL estimates were approved by the Expert Consultation Panel for Provisional Advisory Levels in November 2006. No reliable data were found on oral exposure, making it impractical to estimate PALs for drinking water. Since H2S exists as a gas, partitioning to air is likely to occur with an environmental release. H2S inhalation PAL values for 24 hr exposure are: PAL 1 = 1.2 ppm; PAL 2 = 7.0 ppm; and PAL 3 = 27 ppm; the 30-d and 90-d inhalation exposure values are: PAL 1 = 0.85 ppm and PAL 2 = 3.0 ppm. PAL 3 values for 30-d and 90-d are not recommended due to insufficient data. Long-term data were insufficient to estimate 2-year inhalation PALs.

  20. Provisional tables on the zinc content of foods.

    PubMed

    Murphy, E W; Willis, B W; Watt, B K

    1975-04-01

    A critical and exhaustive review of published and unpublished data on the zinc content of foods showed that, with few exceptions, the major dietary sources of zinc were foods of animal origin. Oysters, which contained more than 5 mg. zinc per 3-oz. cooked portion, were an outstanding source of zinc. Lean beef and beef liver were also among the foods highest in zinc and ground beef was a good source. Dark meat of poultry contained more zinc than light meat, and turkey was higher in zinc than chicken. Egg yolk, but not egg white, was relatively high in zinc, as were nonfat dry milk and Cheddar cheese. Foods of plant origin, like those of animal origin, varied widely in zinc content. Cocoa and the milling fractions of bran and germ of wheat were high in zinc. Seeds of plants, such as muture dry legumes and peanuts, were better sources of zinc than were leaves, stalks, fruits, or roots. Vegetables, fruits, oils, fats, tea, coffee, and carbonated beverages contained little zinc. Factors influencing the zinc content of foods were evaluated. Provisional tables, giving representative values for zinc in more than two hundred foods, both in 100-gm. portions and in common household units, based on this research, are presented. PMID:1090644

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

    ClinicalTrials.gov

    2016-09-07

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

  2. 78 FR 36571 - North American Datum of 1983 (NAD 83) Outer Continental Shelf (OCS) Provisional Official...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-18

    ... Bureau of Ocean Energy Management North American Datum of 1983 (NAD 83) Outer Continental Shelf (OCS) Provisional Official Protraction Diagram (OPDs) AGENCY: Bureau of Ocean Energy Management (BOEM), Interior... Ocean Energy Management. BILLING CODE 4310-MR-P...

  3. LADTAG Progress 2010 and Plans for 2011 and Provisional PELs from Lavage and Blood Data

    NASA Technical Reports Server (NTRS)

    James, John T.

    2010-01-01

    This viewgraph presentation reviews the Lunar Airborne Dust Toxicity Assessment Group (LADTAG) plans and progress for 2010 and 2011. Provisional Permissible Exposure Limits (PPELs) from lavage fluid and blood data are also presented.

  4. 20 CFR 416.999c - How do we determine provisional benefits?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Continuing Or Stopping Disability Or Blindness § 416.999c How do we determine provisional benefits? (a) You may receive up to...

  5. 20 CFR 416.999c - How do we determine provisional benefits?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Continuing Or Stopping Disability Or Blindness § 416.999c How do we determine provisional benefits? (a) You may receive up to...

  6. 20 CFR 416.999c - How do we determine provisional benefits?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Continuing Or Stopping Disability Or Blindness § 416.999c How do we determine provisional benefits? (a) You may receive up to...

  7. 20 CFR 416.999c - How do we determine provisional benefits?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Continuing Or Stopping Disability Or Blindness § 416.999c How do we determine provisional benefits? (a) You may receive up to...

  8. 20 CFR 416.999c - How do we determine provisional benefits?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Continuing Or Stopping Disability Or Blindness § 416.999c How do we determine provisional benefits? (a) You may receive up to...

  9. Comparative evaluation of surface properties of enamel and different esthetic restorative materials under erosive and abrasive challenges: An in vitro study

    PubMed Central

    Kaur, Simranjeet; Makkar, Sameer; Kumar, Rajneesh; Pasricha, Shinam; Gupta, Pranav

    2015-01-01

    Introduction: Noncarious tooth surface loss is a normal physiological process occurring throughout the life, but it can often become a problem affecting function, esthetics or cause pain. Aim: The purpose of this study was to assess the effect of erosive and abrasive challenges on the surface microhardness and surface wear of enamel and three different restorative materials, that is, nanofilled composite, microfilled composite and resin-modified glass ionomer cement (RMGIC) by using Vickers microhardness tester and profilometer respectively. Subjects and Methods: Nanofilled composite (Filtek™ Z350 × T), microfilled composite (Heliomolar®) and RMGIC (Fuji II LC) were used in the study. Results: Nanofilled composite resin has the best resistance to erosion and/or abrasion among all the materials tested, followed by microfilled composite and RMGIC respectively. Conclusion: Toothbrush abrasion has a synergistic effect with erosion on substance loss of human enamel, composites, and RMGIC. The susceptibility to acid and/or toothbrush abrasion of human enamel was higher compared to restorative materials. PMID:26752876

  10. Health-based Provisional Advisory Levels (PALs) for homeland security.

    PubMed

    Adeshina, Femi; Sonich-Mullin, Cynthia; Ross, Robert H; Wood, Carol S

    2009-12-01

    The Homeland Security Presidential Directive #8 (HSPD-8) for National Emergency Preparedness was issued to " establish policies to strengthen the preparedness of the United States to prevent and respond to threatened or actual domestic terrorist attacks, major disasters, and other emergencies by requiring a national domestic all- hazards preparedness goal. "In response to HSPD-8 and HSPD-22 (classified) on Domestic Chemical Defense, the US Environmental Protection Agency (US EPA) National Homeland Security Research Center (NHSRC) is developing health-based Provisional Advisory Levels (PALs) for priority chemicals (including chemical warfare agents, pesticides, and toxic industrial chemicals) in air and drinking water. PALs are temporary values that will neither be promulgated, nor be formally issued as regulatory guidance. They are intended to be used at the discretion of risk managers in emergency situations. The PAL Program provides advisory exposure levels for chemical agents to assist in emergency planning and response decision-making, and to aid in making informed risk management decisions for evacuation, temporary re-entry into affected areas, and resumed-use of infrastructure, such as water resources. These risk management decisions may be made at the federal, state, and local levels. Three exposure levels (PAL 1, PAL 2, and PAL 3), distinguished by severity of toxic effects, are developed for 24-hour, 30-day, 90-day, and 2-year durations for potential exposure to drinking water and ambient air by the general public. Developed PALs are evaluated both by a US EPA working group, and an external multidisciplinary panel to ensure scientific credibility and wide acceptance. In this Special Issue publication, we present background information on the PAL program, the methodology used in deriving PALs, and the technical support documents for the derivation of PALs for acrylonitrile, hydrogen sulfide, and phosgene.

  11. Health-based Provisional Advisory Levels (PALs) for homeland security.

    PubMed

    Adeshina, Femi; Sonich-Mullin, Cynthia; Ross, Robert H; Wood, Carol S

    2009-12-01

    The Homeland Security Presidential Directive #8 (HSPD-8) for National Emergency Preparedness was issued to " establish policies to strengthen the preparedness of the United States to prevent and respond to threatened or actual domestic terrorist attacks, major disasters, and other emergencies by requiring a national domestic all- hazards preparedness goal. "In response to HSPD-8 and HSPD-22 (classified) on Domestic Chemical Defense, the US Environmental Protection Agency (US EPA) National Homeland Security Research Center (NHSRC) is developing health-based Provisional Advisory Levels (PALs) for priority chemicals (including chemical warfare agents, pesticides, and toxic industrial chemicals) in air and drinking water. PALs are temporary values that will neither be promulgated, nor be formally issued as regulatory guidance. They are intended to be used at the discretion of risk managers in emergency situations. The PAL Program provides advisory exposure levels for chemical agents to assist in emergency planning and response decision-making, and to aid in making informed risk management decisions for evacuation, temporary re-entry into affected areas, and resumed-use of infrastructure, such as water resources. These risk management decisions may be made at the federal, state, and local levels. Three exposure levels (PAL 1, PAL 2, and PAL 3), distinguished by severity of toxic effects, are developed for 24-hour, 30-day, 90-day, and 2-year durations for potential exposure to drinking water and ambient air by the general public. Developed PALs are evaluated both by a US EPA working group, and an external multidisciplinary panel to ensure scientific credibility and wide acceptance. In this Special Issue publication, we present background information on the PAL program, the methodology used in deriving PALs, and the technical support documents for the derivation of PALs for acrylonitrile, hydrogen sulfide, and phosgene. PMID:19814653

  12. Health-based Provisional Advisory Levels (PALs) for Homeland Security

    SciTech Connect

    Adeshina, Femi; Sonich-Mullin, Synthia; Wood, Carol S

    2009-01-01

    In compliance with Homeland Security Presidential Directive No.8, the US EPA National Homeland Security Research Center, in collaboration with the Department of Energy, is developing health-based Provisional Advisory Levels (PALs) for priority toxic industrial chemicals, pesticides, and chemical warfare agents in air and drinking water. The PALs Program will provide exposure levels to assist emergency response decision-making, and to serve as criteria for determining re-use and re-entry into affected areas resulting from transport/storage accidents, natural disasters, and subversive activities. PALs are applicable at federal, state, and local levels, and are intended for use in homeland security efforts, public health, law enforcement, and emergency response, as well as decisions by water utilities, and national and regional EPA offices. PALS have not been promulgated nor have they been formally issued as regulatory guidance. They are intended to be used at the discretion of risk managers in emergency situations when site specific risk assessments are not available. Three levels (PAL 1, PAL 2, and PAL 3), distinguished by severity of toxic effects, are developed for 24-hour, 30-day, 90-day, and 2-year durations of potential drinking water and inhalation exposures for the general public. Draft PALs are evaluated both by an EPA working group, and an external multidisciplinary panel to ensure scientific credibility and wide acceptance. In this issue, we present background information on the PAL program, the methodology used in deriving PALs, and the technical support documents for the derivation of PALs for acrylonitrile, phosgene, hydrogen chloride, and hydrogen sulfide.

  13. Restoring primary anterior teeth.

    PubMed

    Waggoner, William F

    2002-01-01

    A variety of esthetic restorative materials are available for restoring primary incisors. Knowledge of the specific strengths, weakness, and properties of each material will enhance the clinician's ability to make the best choice of selection for each individual situation. Intracoronal restorations of primary teeth may utilize resin composites, glass ionomer cements, resin-modified ionomers, or polyacid-modified resins. Each has distinct advantages and disadvantages and the clinical conditions of placement may be a strong determining factor as to which material is utilized. Full coronal restoration of primary incisors may be indicated for a number of reasons. Crowns available for restoration of primary incisors include those that are directly bonded onto the tooth, which generally are a resin material, and those crowns that are luted onto the tooth and are some type of stainless steel crown. However, due to lack of supporting clinical data, none of the crowns can be said to be superior to the others under all circumstances. Though caries in the mandibular region is rare, restorative solutions for mandibular incisors are needed. Neither stainless steel crowns nor celluloid crown forms are made specifically for mandibular incisors. Many options exist to repair carious primary incisors, but there is insufficient controlled, clinical data to suggest that one type of restoration is superior to another. This does not discount the fact that dentists have been using many of these crowns for years with much success. Operator preferences, esthetic demands by parents, the child's behavior, and moisture and hemorrhage control are all variables which affect the decision and ultimate outcome of whatever restorative treatment is chosen.

  14. Restoring primary anterior teeth.

    PubMed

    Waggoner, William F

    2002-01-01

    A variety of esthetic restorative materials are available for restoring primary incisors. Knowledge of the specific strengths, weakness, and properties of each material will enhance the clinician's ability to make the best choice of selection for each individual situation. Intracoronal restorations of primary teeth may utilize resin composites, glass ionomer cements, resin-modified ionomers, or polyacid-modified resins. Each has distinct advantages and disadvantages and the clinical conditions of placement may be a strong determining factor as to which material is utilized. Full coronal restoration of primary incisors may be indicated for a number of reasons. Crowns available for restoration of primary incisors include those that are directly bonded onto the tooth, which generally are a resin material, and those crowns that are luted onto the tooth and are some type of stainless steel crown. However, due to lack of supporting clinical data, none of the crowns can be said to be superior to the others under all circumstances. Though caries in the mandibular region is rare, restorative solutions for mandibular incisors are needed. Neither stainless steel crowns nor celluloid crown forms are made specifically for mandibular incisors. Many options exist to repair carious primary incisors, but there is insufficient controlled, clinical data to suggest that one type of restoration is superior to another. This does not discount the fact that dentists have been using many of these crowns for years with much success. Operator preferences, esthetic demands by parents, the child's behavior, and moisture and hemorrhage control are all variables which affect the decision and ultimate outcome of whatever restorative treatment is chosen. PMID:12412967

  15. Comparison of marginal adaptation of mineral trioxide aggregate, glass ionomer cement and intermediate restorative material as root-end filling materials, using scanning electron microscope: An in vitro study

    PubMed Central

    Gundam, Sirisha; Patil, Jayaprakash; Venigalla, Bhuvan Shome; Yadanaparti, Sravanthi; Maddu, Radhika; Gurram, Sindhura Reddy

    2014-01-01

    Aim: The present study compares the marginal adaption of Mineral Trioxide Aggregate (MTA), Glass Ionomer Cement (GIC) and Intermediate Restorative Material (IRM) as root-end filling materials in extracted human teeth using Scanning Electron Microscope (SEM). Materials and Methods: Thirty single rooted human teeth were obturated with Gutta-percha after cleaning and shaping. Apical 3 mm of roots were resected and retrofilled with MTA, GIC and IRM. One millimeter transverse section of the retrofilled area was used to study the marginal adaptation of the restorative material with the dentin. Mounted specimens were examined using SEM at approximately 15 Kv and 10-6 Torr under high vacuum condition. At 2000 X magnification, the gap size at the material-tooth interface was recorded at 2 points in microns. Statistical Analysis: One way ANOVA Analysis of the data from the experimental group was carried out with gap size as the dependent variable, and material as independent variable. Results: The lowest mean value of gap size was recorded in MTA group (0.722 ± 0.438 μm) and the largest mean gap in GIC group (1.778 ± 0.697 μm). Conclusion: MTA showed least gap size when compared to IRM and GIC suggesting a better marginal adaptation. PMID:25506146

  16. Bio-active glass air-abrasion has the potential to remove resin composite restorative material selectively

    NASA Astrophysics Data System (ADS)

    Milly, Hussam; Andiappan, Manoharan; Thompson, Ian; Banerjee, Avijit

    2014-06-01

    The aims of this study were to assess: (a) the chemistry, morphology and bioactivity of bio-active glass (BAG) air-abrasive powder, (b) the effect of three air-abrasion operating parameters: air pressure, powder flow rate (PFR) and the abrasive powder itself, on the selective removal of resin composite and (c) the required “time taken”. BAG abrasive particles were characterised using scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDX) and Fourier-transform infrared spectroscopy (FTIR). Standardised resin composite restorations created within an enamel analogue block (Macor™) in vitro, were removed using air-abrasion undersimulated clinical conditions. 90 standardised cavities were scanned before and after resin composite removal using laser profilometry and the volume of the resulting 3D images calculated. Multilevel linear model was used to identify the significant factors affecting Macor™ removal. BAG powder removed resin composite more selectively than conventional air-abrasion alumina powder using the same operating parameters (p < 0.001) and the effect of altering the unit's operating parameters was significant (p < 0.001). In conclusion, BAG powder is more efficient than alumina in the selective removal of resin composite particularly under specific operating parameters, and therefore may be recommended clinically as a method of preserving sound enamel structure when repairing and removing defective resin composite restorations.

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

    PubMed Central

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

    2016-01-01

    Introduction With the enormous change in life style pattern of a common man through the past few decades, there has been proportional variation in the amount and frequency of consumption of drinks. An increased consumption of these drinks will concurrently increase enamel surface roughness by demineralization, resulting in hypersensitivity and elevated caries risk. Aim The present study was designed to evaluate the erosive potential of commercially available drinks on tooth enamel and various tooth coloured restorative materials. Materials and Methods Extracted human teeth were taken and divided into four groups i.e. tooth enamel, glass ionomer cement, composite and compomer. Four commercially available drinks were chosen these were Coca -Cola, Nimbooz, Frooti and Yakult. The pH of each drink was measured. Each group was immersed in various experimental drinks for a period of 14 days. The erosive potential of each drink was measured by calculating the change in average surface roughness of these groups after the immersion protocol in various drinks. The data analysis was done by One Way Anova, Post-Hoc Bonferroni, and paired t –test. Results Group II-GIC showed highest values for mean of change in average surface roughness and the values were statistically significant (p<0.001) with tooth enamel, composite and compomer (p=0.002). Coca-cola showed the highest erosive potential and Yakult showed the lowest, there was no statistical significant difference between the results shown by Yakult and Frooti. Conclusion Characteristics which may promote erosion of enamel and tooth coloured restorative materials were surface texture of the material and pH of the drinks. PMID:27437343

  18. Effect of exposure time on the color stability of resin-based restorative materials when polymerized with quartz-tungsten halogen and LED light.

    PubMed

    Rüttermann, Stefan; Suyoun, Kim; Raab, Wolfgang H-M; Janda, Ralf

    2010-10-01

    The objective of this study was to investigate the effect of exposure time on color stability of resin-based restorative materials when polymerized with quartz-tungsten halogen light (QTH) or light-emitting diode light (LED). Eight samples of Ceram-X Mono, Dyract eXtra, and Tetric EvoCeram each were cured for 10, 20, and 60 s with QTH or LED. The CIE-Lab values (L*, a*, b*) were measured prior to and after performing water storage or a Suntest, and ΔL, Δa, Δb, and ΔE were calculated. Statistical analysis (p < 0.05) showed significant changes of the color values after each of the aging processes as well as between ΔL, Δa, Δb, and ΔE of the materials in dependence of the curing device, exposure time, aging condition, and material formulation. LED performed similarly or even better with 10-s exposure time than QTH with 20 s. No improvement of color stability was achieved with increasing exposure time of 60 s either for LED or for QTH. Exposure time, emission spectrum of the light-curing device, as well as the individual material formulation influence color stability. There is apparently an exposure time above which the individual material formulation, especially type and amount of photoinitiator or synergist, dominate the color stability.

  19. A finite element study of teeth restored with post and core: Effect of design, material, and ferrule

    PubMed Central

    Upadhyaya, Viram; Bhargava, Akshay; Parkash, Hari; Chittaranjan, B.; Kumar, Vivek

    2016-01-01

    Background: Different postdesigns and materials are available; however, no consensus exists regarding superiority for stress distribution. The aim of this study was to evaluate the effect of design and material of post with or without ferrule on stress distribution using finite element analysis. Materials and Methods: A total of 12 three-dimensional (3D) axisymmetric models of postretained central incisors were made: Six with ferrule design and six without it. Three of these six models had tapered posts, and three had parallel posts. The materials tested were titanium post with a composite resin core, nickel chromium cast post and core, and fiber reinforced composite (FRC) post with a composite resin core. The stress analysis was done using ANSYS software. The load of 100 N at an angle of 45΀ was applied 2 mm cervical to incisal edge on the palatal surface and results were analyzed using 3D von Mises criteria. Results: The highest amount of stress was in the cervical region. Overall, the stress in the tapered postsystem was more than the parallel one. FRC post and composite resin core recorded minimal stresses within the post but the stresses transmitted to cervical dentin were more as compared to other systems. Minimal stresses in cervical dentine were observed where the remaining coronal dentin was strengthen by ferrule. Conclusion: A rigid material with high modulus of elasticity for post and core system creates most uniform stress distribution pattern. Ferrule provides uniform distribution of stresses and decreases the cervical stresses. PMID:27274343

  20. Creating esthetic composite restorations.

    PubMed

    Grin, D

    2000-05-01

    The purpose of this article is to describe a fabrication technique to assist dental technicians creating esthetic indirect composite restorations. After the teeth have been prepared and the models completed, the technician can begin the fabrication process. Translucent dentin is selected to reduce opacity and enhance the blend with the remaining dentition. High chroma modifiers can then be placed into the fossa area to replicate dentin seen in natural dentition. Different incisal materials can then be layered into the build-up to regulate the value of the restoration. Special effects such as hypocalcification are placed internally to mimic naturally occurring esthetics. Realistic anatomy is created using a small-tipped instrument directly into the final layer of uncured enamel material. Fissure characterization is placed in the restoration to match existing dentition. Fit and margins are verified on separate dies to minimize discrepancies. Path of insertion and proximal contacts are established on a solid model to minimize chairside adjustments.

  1. Longevity of Posterior Composite Restorations

    PubMed Central

    Opdam, N.J.M.; van de Sande, F.H.; Bronkhorst, E.; Cenci, M.S.; Bottenberg, P.; Pallesen, U.; Gaengler, P.; Lindberg, A.; Huysmans, M.C.D.N.J.M.; van Dijken, J.W.

    2014-01-01

    The aim of this meta-analysis, based on individual participant data from several studies, was to investigate the influence of patient-, materials-, and tooth-related variables on the survival of posterior resin composite restorations. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a search resulting in 12 longitudinal studies of direct posterior resin composite restorations with at least 5 years’ follow-up. Original datasets were still available, including placement/failure/censoring of restorations, restored surfaces, materials used, reasons for clinical failure, and caries-risk status. A database including all restorations was constructed, and a multivariate Cox regression method was used to analyze variables of interest [patient (age; gender; caries-risk status), jaw (upper; lower), number of restored surfaces, resin composite and adhesive materials, and use of glass-ionomer cement as base/liner (present or absent)]. The hazard ratios with respective 95% confidence intervals were determined, and annual failure rates were calculated for subgroups. Of all restorations, 2,816 (2,585 Class II and 231 Class I) were included in the analysis, of which 569 failed during the observation period. Main reasons for failure were caries and fracture. The regression analyses showed a significantly higher risk of failure for restorations in high-caries-risk individuals and those with a higher number of restored surfaces. PMID:25048250

  2. Effects of various chair-side surface treatment methods on dental restorative materials with respect to contact angles and surface roughness.

    PubMed

    Sturz, Candida R C; Faber, Franz-Josef; Scheer, Martin; Rothamel, Daniel; Neugebauer, Jörg

    2015-01-01

    Available chair-side surface treatment methods may adversely affect prosthetic materials and promote plaque accumulation. This study investigated the effects of treatment procedures on three resin restorative materials, zirconium-dioxide and polyetheretherketone in terms of surface roughness and hydrophobicity. Treatments were grinding with silicon carbide paper or white Arkansas stone, blasting with prophylaxis powder and polishing with diamond paste. Surface roughness was assessed using confocal laser scanning. Hydrophobicity as measured by water contact angle was determined by computerized image analysis using the sessile drop technique. All of the specific surface treatments performed led to significant changes in contact angle values and surface roughness (Ra) values. Median contact angle values ranged from 51.6° to 114°. Ra values ranged from 0.008 µm to 2.917 µm. Air-polishing as well as other polishing procedures increased surface roughness values in all materials except zirconium dioxide. Polyetheretherketone displayed greatest change in contact angle values after air-polishing treatment. PMID:26632228

  3. Restorative Nurse Assistant. Instructor Guide.

    ERIC Educational Resources Information Center

    Missouri Univ., Columbia. Instructional Materials Lab.

    This curriculum material covers the basic orientation and necessary skills which would enable the practicing Certified Nurse Assistant to be trained as a Restorative Nurse Assistant. The shift in emphasis from maintenance care to restorative care in the long-term care setting has created a need for trained paraprofessionals who are competent in…

  4. A comparison of tissue reaction to MTA and an experimental root-end restorative material in rats.

    PubMed

    Modaresi, Jalil; Yavari, S Amir Saeid; Dianat, S Omid; Shahrabi, Shokufeh

    2005-08-01

    The purpose of this study was to compare the biocompatibility of a new experimental root-end filling material, "Cold Ceramic" (CC), with mineral trioxide aggregate (MTA) in rats. After anaesthetising 10 rats and raising tissue flaps, tablets of the material were placed subcutaneously. Five rats were followed for seven days and five for 30 days. An incision without any implanted material was used as a control. Histological analyses were performed with regard to number, type and location of the inflammatory cells and type of surrounding tissue. Kruskal-Wallis and Mann-Whitney statistical tests were used. Comparing inflammatory reactions between the two experimental groups (MTA and CC) and the control group showed significant differences after seven days (p = 0.031). There were no significant differences between CC and MTA groups after seven days (p = 0.222) and after 30 days (p = 0.063). The results suggested that MTA and CC are both biocompatible. It appears that MTA induces less inflammatory response in short periods of observation, but CC may be more biocompatible for slightly longer periods.

  5. 75 FR 14144 - Availability for Non-Exclusive, Exclusive, or Partially Exclusive Licensing of U.S. Provisional...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-24

    ... invention. ADDRESSES: Commander, U.S. Army Medical Research and Materiel Command, ATTN: Command Judge.... Provisional Patent Application Concerning Medical Delivery System AGENCY: Department of the Army, DoD. ACTION.... Provisional Patent Application Serial No. 61/ ] 312,908 entitled ``Medical Delivery System,'' filed March...

  6. 75 FR 4793 - Availability for Non-Exclusive, Exclusive, or Partially Exclusive Licensing of U.S. Provisional...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-29

    .... Provisional Patent Application Concerning Blast Wave Sensor AGENCY: Department of the Army, DoD. ACTION.... Provisional Patent Application Serial No. 61/292,095 entitled ``Blast Wave Sensor,'' filed January 4, 2010...) 619-5034. SUPPLEMENTARY INFORMATION: The invention relates to blast wave sensors and their use...

  7. Self-Healing Efficiency of Cementitious Materials Containing Microcapsules Filled with Healing Adhesive: Mechanical Restoration and Healing Process Monitored by Water Absorption

    PubMed Central

    Li, Wenting; Jiang, Zhengwu; Yang, Zhenghong; Zhao, Nan; Yuan, Weizhong

    2013-01-01

    Autonomous crack healing of cementitious composite, a construction material that is susceptible to cracking, is of great significance to improve the serviceability and to prolong the longevity of concrete structures. In this study, the St-DVB microcapsules enclosing epoxy resins as the adhesive agent were embedded in cement paste to achieve self-healing capability. The self-healing efficiency was firstly assessed by mechanical restoration of the damaging specimens after being matured. The flexural and compressive configurations were both used to stimulate the localized and distributed cracks respectively. The effects of some factors, including the content of microcapsules, the curing conditions and the degree of damage on the healing efficiency were investigated. Water absorption was innovatively proposed to monitor and characterize the evolution of crack networks during the healing process. The healing cracks were observed by SEM-EDS following. The results demonstrated that the capsule-containing cement paste can achieve the various mechanical restorations depending on the curing condition and the degree of damage. But the voids generated by the surfactants compromised the strength. Though no noticeable improved stiffness obtained, the increasing fracture energy was seen particularly for the specimen acquiring 60% pre-damage. The sorptivity and amount of water decreased with cracks healing by the adhesive, which contributed to cut off and block ingress of water. The micrographs by SEM-EDS also validated that the cracks were bridged by the hardened epoxy as the dominated elements of C and O accounted for 95% by mass in the nearby cracks. PMID:24312328

  8. 10 CFR 903.21 - Completion of rate development; provisional rates.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    .... (a) Following completion of the consultation and comment period and review of any oral and written... into effect on an interim basis (Provisional Rates); or (3) develop rates which in the Administrator's judgment should be confirmed, approved, and placed into effect by the FERC on a final basis without...

  9. 76 FR 49751 - Perfect Fitness, Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-11

    ... accordance with the terms of 16 CFR 1118.20(e). Published below is a provisionally-accepted Settlement... approximately ten thousand (10,000) ``Perfect Pullup'' exercise equipment (``Subject Products''). Retailers... sold for approximately $80-$100 through major sporting goods stores, online retailers, and...

  10. 76 FR 49453 - CVS Pharmacy, Inc., Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-10

    ... Product Safety Commission. ACTION: Notice. SUMMARY: It is the policy of the Commission to publish settlements which it provisionally accepts under the Consumer Product Safety Act in the Federal Register in... knowingly violated the CPSA and asserts that at the time it sold the Jackets, CVS did not have...

  11. 76 FR 63906 - Henry Gordy International, Inc., Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-14

    ...: Consumer Product Safety Commission. ACTION: Notice. SUMMARY: It is the policy of the Commission to publish settlements which it provisionally accepts under the Consumer Product Safety Act in the Federal Register in... their mouth, the dart can be inhaled into the throat and it can prevent the child from breathing....

  12. 75 FR 55777 - Pro-Pac Distributing Corp., Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-14

    ... COMMISSION Pro-Pac Distributing Corp., Provisional Acceptance of a Settlement Agreement and Order AGENCY... Agreement with Pro-Pac Distributing Corp., containing a civil penalty of $125,000.00. DATES: Any interested person may ask the Commission not to accept this agreement or otherwise comment on its contents by...

  13. 77 FR 63801 - Aqua-Leisure Industries, Inc., Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-17

    ... From the Federal Register Online via the Government Publishing Office ] CONSUMER PRODUCT SAFETY COMMISSION Aqua-Leisure Industries, Inc., Provisional Acceptance of a Settlement Agreement and Order AGENCY: Consumer Product Safety Commission. ACTION: Notice. SUMMARY: It is the policy of the Commission to...

  14. Directory of Documentation and Information Services in Adult Education. Provisional Edition.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific, and Cultural Organization, Paris (France). Adult Education Div.

    The directory was prepared as part of a comprehensive effort for improving the international network for the exchange of documentation, information, ideas, and experiences, in the field of adult education. The provisional edition will be corrected and updated after March 1976. A work-sheet and coding instructions are included for this purpose. In…

  15. 20 CFR 404.1592e - How do we determine provisional benefits?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false How do we determine provisional benefits? 404... in April 2004. His disability benefit had previously terminated in January 2003. Since Mr. K meets... beginning April 2004 while we determine whether he is disabled and whether his current impairment(s) is...

  16. 20 CFR 404.1592e - How do we determine provisional benefits?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false How do we determine provisional benefits? 404... in April 2004. His disability benefit had previously terminated in January 2003. Since Mr. K meets... beginning April 2004 while we determine whether he is disabled and whether his current impairment(s) is...

  17. 75 FR 76405 - Winter Bee, Inc., Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-08

    ... COMMISSION Winter Bee, Inc., Provisional Acceptance of a Settlement Agreement and Order AGENCY: Consumer... Agreement with Winter Bee, Inc., containing a civil penalty of $200,000.00, to be suspended except for $40.... Settlement Agreement 1. In accordance with 16 CFR 1118.20, Winter Bee, Inc. (``Winter Bee'') and the...

  18. 76 FR 37793 - Viking Range Corporation, Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-28

    ... COMMISSION Viking Range Corporation, Provisional Acceptance of a Settlement Agreement and Order AGENCY... Agreement with Viking Range Corporation, containing a civil penalty of $450,000.00. DATES: Any interested... 1. In accordance with 16 CFR 1118.20, Viking Range Corporation (``Viking'') and the staff...

  19. 77 FR 19901 - Provisional Unlawful Presence Waivers of Inadmissibility for Certain Immediate Relatives

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-02

    ... application type or area of the United States. Congress also provided in the immigration laws several measures... who are physically present in the United States to request provisional unlawful presence waivers under... in removal proceedings or removed from the United States. Do not send an......

  20. 75 FR 1356 - RC2 Corporation, Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-11

    ... nationwide, and secondarily through RC2's e-commerce websites or as `sub-components' of retail items... through RC2's e-commerce Web sites or as `sub-components' of retail items distributed independently of RC2... accordance with the terms of 16 CFR 1118.20(e). Published below is a provisionally-accepted...

  1. 78 FR 27190 - Williams-Sonoma, Inc., Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-09

    ... COMMISSION Williams-Sonoma, Inc., Provisional Acceptance of a Settlement Agreement and Order AGENCY: Consumer... Agreement with Williams- Sonoma, Inc., containing a civil penalty of $987,500, within twenty (20) days of... Consumer Product Safety Act, 15 U.S.C. 2051-2089 (CPSA) and 16 CFR 1118.20, Williams-Sonoma, Inc. (WS),...

  2. 76 FR 6453 - Raynor Marketing, Ltd., Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-04

    ... COMMISSION Raynor Marketing, Ltd., Provisional Acceptance of a Settlement Agreement and Order AGENCY... Agreement with Raynor Marketing, Ltd., containing a civil penalty of $390,000.00. DATES: Any interested.... Settlement Agreement 1. In accordance with 16 CFR 1118.20, Raynor Marketing, Ltd. and the staff...

  3. 76 FR 10339 - Ms. Bubbles, Inc., Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-24

    ... COMMISSION Ms. Bubbles, Inc., Provisional Acceptance of a Settlement Agreement and Order AGENCY: Consumer... Agreement with Ms. Bubbles, Inc., containing a civil penalty of $40,000.00. \\1\\ The Commission voted 5-0 to... Matter of Ms. Bubbles, Inc.; SETTLEMENT AGREEMENT 1. In accordance with 16 C.F.R. Sec. 1118.20,...

  4. Student Financial Aid, Academic Year 2011-12. First Look. (Provisional Data). NCES 2013-178

    ERIC Educational Resources Information Center

    Ginder, Scott A.; Kelly-Reid, Janice E.

    2013-01-01

    The Integrated Postsecondary Education Data System (IPEDS) collects institution-level data from postsecondary institutions in the United States (50 states and the District of Columbia) and other U.S. jurisdictions (see appendix A for a list of other U.S. jurisdictions). This "First Look" presents findings from the provisional data of the IPEDS…

  5. 76 FR 55648 - Sunsations Inc., Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-08

    ... From the Federal Register Online via the Government Publishing Office CONSUMER PRODUCT SAFETY... Product Safety Commission. ACTION: Notice. SUMMARY: It is the policy of the Commission to publish settlements which it provisionally accepts under the Consumer Product Safety Act in the Federal Register...

  6. 77 FR 58098 - Haier America Trading, LLC, Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-19

    ... accordance with the terms of 16 CFR 1118.20(e). Published below is a provisionally-accepted Settlement... retailers, approximately 53,800 electric blenders (``Blenders''). The Blenders were sold at retail stores in...(e). If the Commission does not receive any written request not to accept the Agreement within...

  7. 10 CFR 903.21 - Completion of rate development; provisional rates.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... into effect on an interim basis (Provisional Rates); or (3) develop rates which in the Administrator's judgment should be confirmed, approved, and placed into effect by the FERC on a final basis without being placed into effect on an interim basis. A statement shall be prepared and made available to the...

  8. Natural restoration

    SciTech Connect

    Kamlet, K.S.

    1993-02-01

    After a company pays millions of dollars to clean up contaminated site, its liability may not be over. It may have to spend tens of millions more to restore damaged natural resources under an oft-overlooked Superfund program. Examples of liability are cited in this report from the Exxon Valdez oil spill and a pcb leak which contaminated a harbor.

  9. A Comparative Evaluation of the Amount of Fluoride Release and Re-Release after Recharging from Aesthetic Restorative Materials: An in vitro Study

    PubMed Central

    Bansal, Ruchika

    2015-01-01

    Aim To measure the amount of fluoride released and re released after recharging from various restorative materials: Conventional Glass Ionomer Cement (Fuji II), Light Cure Resin Modified GIC (Fuji II LC), Giomer (Beautifil II), Compomer (Dyract). Materials and Methods Fifteen cylindrical specimens were prepared from each material. The specimens were immersed in 20 ml of deionized water. The amount of released fluoride was measured during the 1st day, 7th day and on the day15 by using specific fluoride electrode and an ion-analyser. After 15 days each material was divided into three Sub Groups of five samples each. Sub Group A served as control, Sub Group B was exposed to 2% NaF solution, Sub Group C to 1000ppm F toothpaste. The amount of fluoride re-released was measured during the 1st day, 7th day and on the day15 by using specific fluoride electrode and an ion-analyser. The results were statistically analysed using analysis of variance (one-way ANOVA) and Tukey Kramer multiple comparison tests (p≤0.05). Results Independent of the observation time period of the study the Conventional GIC released the highest amount of fluoride followed by RMGIC, Giomer and Compomer. The initial burst effect was seen with GIC’S but not with Giomer and Compomer. After topical fluoride application fluoride re release was highest in Sub Group B and GIC had a greater recharging ability followed by RMGIC, Giomer and Compomer. The fluoride re release was greatest on 1st day followed by rapid return to near exposure levels. Conclusion From the study it was concluded that, the initial Fluoride release was highest from Conventional GIC followed by Resin Modified GIC, Giomer and Compomer. The Fluoride re release was high when recharging with professional regime (2% NaF) as compared to home regime (Toothpaste). Conventional GIC had a greater recharging ability followed by Resin Modified GIC, Giomer and Compomer. PMID:26436037

  10. Esthetic and function rehabilitation of severely worn dentition with prosthetic-restorative approach and VDO increase. Case report

    PubMed Central

    GARGARI, M.; LORÈ, B.; CERUSO, F.M.

    2014-01-01

    SUMMARY Objective. The aim of this study is to report a case of restorative treatment of severely worn dentition. In this case report, the erosive/abrasive worn dentition have been reconstructed with metal ceramic crown on the posterior teeth and with ceramic veneers on the anterior teeth 1.3 – 2.3 and 3.4 – 4.3. Methods. A prosthetic treatment was proposed to a male patient of 58 years old having a clinically significant tooth wear. After clinical exam, impressions of maxillary and mandible arches were taken with alginate to obtain preliminary casts for diagnostic waxing to all maxillary and mandibular teeth and fabrication of all provisional crowns in acrylic resin for posterior teeth, and from the diagnostic wax-up were fabricated a silicone guide masks for anterior teeth. An increase in VDO should be determined on the basis of a need to accomplish satisfactory and aesthetically pleasing restorations; it was proposed to increase the incisal lenght of the maxillary anterior incisors, together with alteration of the VDO 3 mm anteriorly. The posterior teeth 1.6 - 1.5 - 1.4 - 2.4 - 2.6 - 3.5 - 3.6 - 3.7 - 4.4 - 4.7, where the amount of tissue lost was greater, were recontructed with metal ceramic crowns. Two implants (Nobel replace 4.3x10) was placed. The implant were located in the area 4.5 – 4.6. The anterior teeth were restored with veneers. Discussion and results. The prosthetic challenge with restoring severely worn dentitions is to preserve as much of the already diminished tooth structure as possible for retention while also providing enough interocclusal space for the restorative material. PMID:25694800

  11. Use of resin-bonded partial coverage ceramic restorations to treat incomplete fractures in posterior teeth: a clinical report.

    PubMed

    Liebenberg, W H

    1996-11-01

    The objective of restorative treatment of teeth with incomplete fractures is to minimize flexure of the compromised cusps to prevent propagation of the crack. These goals can be addressed with resin-bonded posterior ceramic restorations, but long-term integrity rests on the efficiency of the restoration's bond to the dental hard tissues. Success is dependent on diligent operative performance throughout the entire procedure. Some tips for achieving successful preparation, provisionalization, and partial-coverage restoration of the incompletely fractured posterior tooth are discussed.

  12. Compressive strength of resin-modified glass ionomer restorative material: effect of P/L ratio and storage time.

    PubMed

    Aratani, Mônica; Pereira, Antônio Carlos; Correr-Sobrinho, Lourenço; Sinhoreti, Mário Alexandre Coelho; Consani, Simonides

    2005-12-01

    The aim of this study was to evaluate the compressive strength of resin-modified glass ionomer cement Fuji II LC and Vitremer, in powder/liquid ratios of 1:1, 1:2 and 1:3, at three periods (24 hours, 7 and 28 days) of storage in distilled water at 37ºC. For each material, P/L ratio and storage time, 5 cylindrical specimens were prepared, with 4mm diameter and 6mm height, in silicon moulds. Specimens were light-cured for 40 seconds at each extremity, removed from the moulds and laterally light-cured (perpendicular to long axis) for 40 seconds, protected as recommended by the manufacturers and immersed for the time tested. The specimens were submitted to compressive strength testing in an Instron machine at a crosshead speed of 1.0mm/min until failure. Data were submitted to ANOVA and Tukey's test (5%), and showed that the compressive strength of resin-modified glass ionomer cement was reduced when P/L ratio was reduced and that the storage in water had little influence on compressive strength.

  13. Restoring Ancestral Language, Restoring Identity.

    ERIC Educational Resources Information Center

    Bannon, Kay T.

    1999-01-01

    Describes the Cherokee Language Renewal Program that was designed to help Cherokee elementary school children learn to function in the dominant culture without sacrificing their own cultural heritage. Explains how the program got started, and reports on how it helps restore a cultural identify to a people who are at risk of losing their identity.…

  14. Biological restorations using tooth fragments.

    PubMed

    Busato, A L; Loguercio, A D; Barbosa, A N; Sanseverino, M do C; Macedo, R P; Baldissera, R A

    1998-02-01

    A "biological" restoration technique using dental fragments and adhesive materials is described. These fragments were obtained from extracted human teeth which had been previously sterilized and stored in a tooth bank. The advantages are: the use of extracted teeth as restorative material, esthetics, and treatment cost. The positive sensation of having back the missing tooth was the most mentioned comment among patients. The disadvantages are: the difficulty of obtaining teeth with the needed characteristics, problems of making an indirect restoration, matching the original color, and the non-acceptance by some patients who consider it strange to have other people's teeth placed in their mouths.

  15. Ultrashort pulsed laser (USPL) application in dentistry: basic investigations of ablation rates and thresholds on oral hard tissue and restorative materials.

    PubMed

    Schelle, Florian; Polz, Sebastian; Haloui, Hatim; Braun, Andreas; Dehn, Claudia; Frentzen, Matthias; Meister, Jörg

    2014-11-01

    Modern ultrashort pulse lasers with scanning systems provide a huge set of parameters affecting the suitability for dental applications. The present study investigates thresholds and ablation rates of oral hard tissues and restorative materials with a view towards a clinical application system. The functional system consists of a 10 W Nd:YVO4 laser emitting pulses with a duration of 8 ps at 1,064 nm. Measurements were performed on dentin, enamel, ceramic, composite, and mammoth ivory at a repetition rate of 500 kHz. By employing a scanning system, square-shaped cavities with an edge length of 1 mm were created. Ablation threshold and rate measurements were assessed by variation of the applied fluence. Examinations were carried out employing a scanning electron microscope and optical profilometer. Irradiation time was recorded by the scanner software in order to calculate the overall ablated volume per time. First high power ablation rate measurements were performed employing a laser source with up to 50 W. Threshold values in the range of 0.45 J/cm(2) (composite) to 1.54 J/cm(2) (enamel) were observed. Differences between any two materials are statistically significant (p < 0.05). Preparation speeds up to 37.53 mm(3)/min (composite) were achieved with the 10 W laser source and differed statistically significant for any two materials (p < 0.05) with the exception of dentin and mammoth ivory (p > 0.05). By employing the 50 W laser source, increased rates up to ∼50 mm(3)/min for dentin were obtained. The results indicate that modern USPL systems provide sufficient ablation rates to be seen as a promising technology for dental applications.

  16. Synergistic effects of H2O2 with components of dental restorative materials on gluconeogenesis in rat kidney tubules.

    PubMed

    Franz-Xaver, Reichl; Jürgen, Durner; Kai, Kehe; Matthias, Folwaczny; Norbert, Kleinsasser; Markus, Schwarz; El-Mahdy, Karim; Reinhard, Hickel

    2003-05-01

    No data are available about (toxic) effects of dental materials administered in combination with H(2)O(2) from dental bleaching compounds. The effect of dental composite components triethyleneglycoldimethacrylate (TEGDMA) and hydroxyethylmethacrylate (HEMA) as well as mercuric chloride (HgCl(2)) and methylmercury chloride (MeHgCl), each in combination with H(2)O(2), was investigated on gluconeogenesis in kidney cells. From rats kidney tubules were prepared. Every 10 min up to 60 min 1-ml samples were drawn from the cell suspension for quantitating the glucose content. Glucose formation in controls was 3.5+/-0.3 nmol/mg.per min (mean+/-SEM, n=21). Relative rates of glucose formation were obtained by expressing individual rates as percentage of the corresponding control. X-Y concentration curves (effective concentration, EC) of the substances were calculated by fitting a four-parametric sigmoid function to the relative rates of the glucose formation at various test concentrations. At the end of the incubation period cell viability was assessed by trypan blue exclusion. Cell viability decreased within the 60 min interval from 90% to approx. 80% (controls), <25 (HEMA), <20 (TEGDMA), <20 (H(2)O(2)) <10 (MeHgCl), and <10 (HgCl(2)). Values of 50% effective concentration (EC(50)) were calculated from fitted curves. EC(50) values were (mmol/l; mean+/-SEM; n=4): HEMA, 17.2+/-2.8; TEGDMA, 1.9+/-0.2; H(2)O(2) 0.22+/-0.03, MeHgCl, 0.016+/-0.0005; and HgCl(2), 0.0017+/-0.0005. No significant decrease of the EC(50) values was found when kidney cells were exposed to HEMA, HgCl(2), or MeHgCl in addition with H(2)O(2) (1-100 microM), compared to those EC(50) values of each compound without H(2)O(2) addition. A significant decrease of the TEGDMA EC(50) values to about 0.25 or 0.04 (mmol/l) was found when cells were exposed to TEGDMA in combination with H(2)O(2) (75 or 100 microM), compared to that TEGDMA EC(50) value without H(2)O(2) addition. The addition of H(2)O(2) (75 and 100

  17. Restoration Process

    NASA Technical Reports Server (NTRS)

    1979-01-01

    In the accompanying photos, a laboratory technician is restoring the once-obliterated serial number of a revolver. The four-photo sequence shows the gradual progression from total invisibility to clear readability. The technician is using a new process developed in an applications engineering project conducted by NASA's Lewis Research Center in conjunction with Chicago State University. Serial numbers and other markings are frequently eliminated from metal objects to prevent tracing ownership of guns, motor vehicles, bicycles, cameras, appliances and jewelry. To restore obliterated numbers, crime laboratory investigators most often employ a chemical etching technique. It is effective, but it may cause metal corrosion and it requires extensive preparatory grinding and polishing. The NASA-Chicago State process is advantageous because it can be applied without variation to any kind of metal, it needs no preparatory work and number recovery can be accomplished without corrosive chemicals; the liquid used is water.

  18. [Multiple agenesis and prosthetic restoration].

    PubMed

    Renault, P

    1990-03-01

    Cases of multiple agenesia present some difficulties in the treatment planing. Three situations may be encountered: limited agenesia, restored by a fixed, bonded or cemented prosthesis, multiple uni- or bimaxillary agenesia without remaining of deciduous teeth, restored by a fixed, bonded or cemented prosthesis or the partial adjacent prosthesis, multiple uni- or bimaxillary agenesia with remaining of deciduous teeth, restored by means of a supra-dental prosthesis. The first two situations have been described in dental literature and are relatively easy to treat. The same is not true for the third situation, where the decision to keep the temporary teeth considerably increases the difficulty of prosthetic restoration. This subject will be illustrated by the presentation of a clinical case of multiple bi-maxillary agenesia. The patient has: on the maxilla: an absence of 9 permanent teeth (18, 15, 14, 12, 22, 23, 24, 25, 28) and the presence of 4 deciduous teeth (62, 63, 64, 65), on the mandible: an absence of all permanent teeth, with the exception of 36 and 46, and the remaining of 4 deciduous teeth (75, 73, 83, 84). The remaining of deciduous teeth and the presence of a very high inter-arch space led to opting for dental coverage so as to keep the deciduous teeth and a proper vertical dimension. The patient wished to solve his "problem" in the maxilla first, and is not wanting to undergo the extraction of his deciduous teeth. The following therapeutic proposal was adapted: On the maxilla, a three-step procedure: first step: building of metal copings on 13, 16 and 26 and metal-ceramic crowns on 11 and 21, second step: building of telescop crowns on 16 and 26 and clasps on 13, 11 and 21, third step: casting of the removable partial denture framework and soldering to the telescop crowns and clasps. On the mandible, a provisional restoration using a supra-dental resin removable partial denture with ceramic occlusal surfaces was adopted. The aesthetic and functional

  19. Class II Resin Composites: Restorative Options.

    PubMed

    Patel, Minesh; Mehta, Shamir B; Banerji, Subir

    2015-10-01

    Tooth-coloured, resin composite restorations are amongst the most frequently prescribed forms of dental restoration to manage defects in posterior teeth. The attainment of a desirable outcome when placing posterior resin composite restorations requires the clinician to have a good understanding of the benefits (as well as the limitations) posed by this material, together with a sound knowledge of placement technique. Numerous protocols and materials have evolved to assist the dental operator with this type of demanding posterior restoration. With the use of case examples, four techniques available are reported here. CPD/Clinical Relevance: This article explores varying techniques for the restoration of Class II cavities using resin composite.

  20. Use of a compact fiber optic spectrometer for spectral feedback during the laser ablation of dental hard tissues and restorative materials

    NASA Astrophysics Data System (ADS)

    Cheng, Joyce Y.; Fan, Kenneth; Fried, Daniel

    2006-02-01

    One perceived disadvantage of caries removal using lasers is the loss of the tactile feedback associated with the handpiece. However, alternative methods of acoustic and optical feedback become available with the laser that can be exploited to provide information about the chemical composition of the material ablated, the ablation efficiency and rate, the depth of the incision, and the surface and plume temperature during ablation. Such information can be used to increase the selectivity of ablation, avoid peripheral thermal damage and excessive heat deposition in the tooth, and provide a mechanism of robotic automation. The objective of this study was to test the hypothesis that a compact fiberoptic spectrometer could be used to differentiate between the ablation of sound and carious enamel and dentin and between dental hard tissues and composite. Sound and carious tooth surfaces along with composite restorative materials were scanned with λ=0.355, 2.79 and 9.3 μm laser pulses at irradiation intensities ranging from 0.5-100 J/cm2 and spectra were acquired from λ=250-900-nm using a compact fiber-optic spectrometer. Emission spectra varied markedly with the laser wavelength and pulse duration. Optical feedback was not successful in differentiating between sound and carious enamel and dentin even with the addition of various chromophores to carious lesion areas. However, the spectral feedback was successfully used to differentiate between composites and sound enamel and dentin enabling the selective removal of composite from tooth surfaces using a computer controlled λ=9.3-μm pulsed CO II laser and scanning system.

  1. Analysis of Resin-Dentin Interface Morphology and Bond Strength Evaluation of Core Materials for One Stage Post-Endodontic Restorations

    PubMed Central

    Bitter, Kerstin; Gläser, Christin; Neumann, Konrad; Blunck, Uwe; Frankenberger, Roland

    2014-01-01

    Purpose Restoration of endodontically treated teeth using fiber posts in a one-stage procedure gains more popularity and aims to create a secondary monoblock. Data of detailed analyses of so called “post-and-core-systems” with respect to morphological characteristics of the resin-dentin interface in combination with bond strength measurements of fiber posts luted with these materials are scarce. The present study aimed to analyze four different post-and-core-systems with two different adhesive approaches (self-etch and etch-and-rinse). Materials and Methods Human anterior teeth (n = 80) were endodontically treated and post space preparations and post placement were performed using the following systems: Rebilda Post/Rebilda DC/Futurabond DC (Voco) (RB), Luxapost/Luxacore Z/Luxabond Prebond and Luxabond A+B (DMG) (LC), X Post/Core X Flow/XP Bond and Self Cure Activator (Dentsply DeTrey) (CX), FRC Postec/MultiCore Flow/AdheSE DC (Ivoclar Vivadent) (MC). Adhesive systems and core materials of 10 specimens per group were labeled using fluorescent dyes and resin-dentin interfaces were analyzed using Confocal Laser Scanning Microscopy (CLSM). Bond strengths were evaluated using a push-out test. Data were analyzed using repeated measurement ANOVA and following post-hoc test. Results CLSM analyses revealed significant differences between groups with respect to the factors hybrid layer thickness (p<0.0005) and number of resin tags (p = 0.02; ANOVA). Bond strength was significantly affected by core material (p = 0.001), location inside the root canal (p<0.0005) and incorporation of fluorescent dyes (p = 0.036; ANOVA). CX [7.7 (4.4) MPa] demonstrated significantly lower bond strength compared to LC [14.2 (8.7) MPa] and RB [13.3 (3.7) MPa] (p<0.05; Tukey HSD) but did not differ significantly from MC [11.5 (3.5) MPa]. Conclusion It can be concluded that bond strengths inside the root canal were not affected by the adhesive approach of the post

  2. Towards an Australian Bioregionalisation Atlas: A provisional area taxonomy of Australia's biogeographical regions.

    PubMed

    Ebach, Malte C; Gillu, Anthony C; Kwan, Alan; Ahyong, Shane T; Murphy, Daniel J; Cassis, Gerasimos

    2013-01-01

    The large number, definition, varied application and validity of named Australian biogeographical regions reflect their ad hoc development via disparate methods or case study idiosyncracies. They do not represent a coherent system. In order to resolve these uncertainties an Australian Bioregionalisation Atlas is proposed as a provisional hierarchical classification, accounting for all known named areas. This provisional area taxonomy includes a diagnosis, description, type locality and map for each named area within the Australian continent, as well as a first-ever area synonymy. Akin to biological classifications, this Atlas seeks to provision universality, objectivity and stability, such that biogeographers, macroecologists and geographers, can test existing areas as well as proposing novel areas. With such a formalised and comparative system in place, practitioners can analyse the definition and relationships of biotic areas, and putatively minimise ad hoc explanations. PMID:26131478

  3. [Morphology of implant restorations in the cuspid area].

    PubMed

    Chiche, G J; Pinault, A

    1990-12-01

    Implant supported posterior restorations must be constructed following established prosthetic principles. The need for screw-retained abutments and the narrow diameter of root form implants dictate additional treatment protocols that fail beyond the scope of conventional prosthetics. Cemented restorations offer simplicity and good control of morphology, but can only be considered if no reservicing and removal of the restoration are anticipated. Screw retained restorations allow for reservicing on remediation but necessitate centering of the fastening screw within the occlusal anatomy. In case of implant misalignment, axis problems are solved with preangled or customized copings, or double frameworks. The diameter of root form implants is significantly smaller than posterior natural teeth and the emergence of the restorations must be progressively flared to achieve proper anatomy. Limited interocclusal space and implant placement may dictate restoring posterior teeth as premolars selecting a short abutment or a UCLA abutment, or overlapping the crowns over the soft tissues. The final selection is best assisted with a diagnostic waxing and with provisional restorations anticipating the completed treatment.

  4. 75 FR 3900 - Availability for Non-Exclusive, Exclusive, or Partially Exclusive Licensing of U.S. Provisional...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-25

    .... Provisional Patent Application Concerning Monoclonal Antibodies Against Glycoprotein of Ebola Sudan Boniface...,725 entitled ``Monoclonal Antibodies Against Glycoprotein of Ebola Sudan Boniface Virus,'' filed... Sudan Boniface virus and methods of producing and using the same. Brenda S. Bowen, Army Federal...

  5. Compliance work for food contact materials: feasibility of the legally required safety assessment of an epoxy/amine-based coating for domestic water pipe restoration.

    PubMed

    Tillner, Jocelyn; Grob, Koni

    2014-01-01

    Options were explored for fulfilling the legally required safety assessment for a widely applied epoxy/amine coating used for restoring corroded domestic drinking water supply systems. The coating was made up of two components mixed shortly before application, the first mainly consisting of bisphenol A diglycidyl ether (BADGE), the second of various amines. The analytically identified starting substances were all authorised, but only constituted a small proportion of the low molecular mass material left after curing and potentially migrating into water. Reaction products synthesised from constituents of the starting components (expected oligomers) could not be eluted from GC even after derivatisation, indicating that standard GC-MS screening would miss most potential migrants. They were detectable by size exclusion chromatography (SEC) after acetylation. HPLC with MS or fluorescence detection was possible for constituents including a BADGE moiety, but phenalkamines could not be detected with adequate sensitivity. Possibilities for determining long-term migration relevant for chronic toxicity are discussed. Analysis in water shortly after application of the coating overestimates migration if migration decreases over time and requires detection limits far out of reach. Analysis of a solvent extract of the coating is easier and provides an upper estimate of what could migrate into the drinking water over the years. However, to satisfy the regulatory requirements, components of the complex mixture need to be identified at lower proportions than those accessible. In vitro testing of the whole mixture for genotoxicity is expected to fail because of the required sensitivity and the glycidyl functions probably wrongly resulting in positive tests. The difficulties in dealing with this situation are discussed. PMID:24761990

  6. Selective targeting of protein, water, and mineral in dentin using UV and IR pulse lasers: the effect on the bond strength to composite restorative materials

    NASA Astrophysics Data System (ADS)

    Sheth, Karishma K.; Staninec, Michal; Sarma, Anupama V.; Fried, Daniel

    2004-05-01

    Previous studies have shown that during the laser irradiation of dentin and bone, thermal damage can be minimized by using a highly absorbed laser wavelength, laser pulses shorter than the thermal relaxation time of the deposited laser energy at that wavelength, and the addition of a layer of water to the tissue surface before ablation. The objective of this study was to investigate the influence of laser pulse duration and wavelength with and without the added water layer on the bond strength of composite to laser prepared dentin surfaces. The specific hypothesis that was tested was that thermal damage to the collagen matrix in dentin compromises the bond strength to composite restorative materials. Three laser systems were employed that were tuned to water, collagen and mineral absorption with pulse durations less than the thermal relaxation time of the deposited energy. The surfaces of human dentin were irradiated by laser irradiation from free-running and Q-switched Er:YSGG lasers (2.79-μm), pulsed CO2 lasers operating at 9.6-μm and a Q-switched Nd:YAG laser operating at 355-nm. A motion control system and a pressurized spray system incorporating a microprocessor controlled pulsed nozzle for water delivery, were used to ensure uniform treatment of the entire surface. Shear bond testing was used to evaluate the adhesive strength in order to access the suitability of laser treated surfaces for bonding. All the laser groups had significantly lower bond strengths than the positive acid etch control group. The highest bond strengths were for the short (<5-μs) Er:YSGG and CO2 groups with water. Laser groups without water had significantly reduced bond strengths.

  7. Infrared laser irradiation of dental enamel using submicrosecond laser pulses with and without an applied water layer: effect on bond strength to restorative materials

    NASA Astrophysics Data System (ADS)

    Sarma, Anupama V.; Staninec, Michal; Le, Charles Q.; Fried, Daniel

    2004-05-01

    Previous studies have shown that during IR laser irradiation at CO2 and Er:YAG laser wavelengths, residual particles of fused non-apatite calcium phosphate phases accumulate that may inhibit adhesion to restorative materials. A layer of water added to the enamel surface before ablation prevents the accumulation of such phases. The objective of this study was to investigate the influence of laser pulse duration and wavelength with and without the added water layer on the bond strength of composite to laser prepared enamel surfaces. The surfaces of bovine enamel were irradiated by three lasers systems: a 0.5-μs Er:YSGG laser. a 25-μs Er:YAG laser and a 5-μs TEA CO2 laser operating at 9.6-μm. A motion control system and a pressurized spray system incorporating a microprocessor controlled pulsed nozzle for water delivery, were used to ensure uniform treatment of the entire surface. There was no significant reduction in the shear-bond strength of enamel to composite for the shorter erbium laser pulses if a water-spray was not used, in contrast to previous results for the 200-μs free-running Er:YAG laser in which the water-spray resulted in significantly higher bond-strengths. Shear-bond strengths for both erbium laser systems were significantly higher than for the CO2 laser irradiated samples and the negative control (no acid-etch) but significantly lower than the positive control group (phosphoric acid-etch). The application of the water-spray markedly influenced the surface morphology for all three laser systems with the most uniform surface preparation being produced by the 25-μs Er:YAG laser and the 5-μs CO2 laser with the water-spray.

  8. Compliance work for food contact materials: feasibility of the legally required safety assessment of an epoxy/amine-based coating for domestic water pipe restoration.

    PubMed

    Tillner, Jocelyn; Grob, Koni

    2014-01-01

    Options were explored for fulfilling the legally required safety assessment for a widely applied epoxy/amine coating used for restoring corroded domestic drinking water supply systems. The coating was made up of two components mixed shortly before application, the first mainly consisting of bisphenol A diglycidyl ether (BADGE), the second of various amines. The analytically identified starting substances were all authorised, but only constituted a small proportion of the low molecular mass material left after curing and potentially migrating into water. Reaction products synthesised from constituents of the starting components (expected oligomers) could not be eluted from GC even after derivatisation, indicating that standard GC-MS screening would miss most potential migrants. They were detectable by size exclusion chromatography (SEC) after acetylation. HPLC with MS or fluorescence detection was possible for constituents including a BADGE moiety, but phenalkamines could not be detected with adequate sensitivity. Possibilities for determining long-term migration relevant for chronic toxicity are discussed. Analysis in water shortly after application of the coating overestimates migration if migration decreases over time and requires detection limits far out of reach. Analysis of a solvent extract of the coating is easier and provides an upper estimate of what could migrate into the drinking water over the years. However, to satisfy the regulatory requirements, components of the complex mixture need to be identified at lower proportions than those accessible. In vitro testing of the whole mixture for genotoxicity is expected to fail because of the required sensitivity and the glycidyl functions probably wrongly resulting in positive tests. The difficulties in dealing with this situation are discussed.

  9. Placement technique for direct posterior composite restorations.

    PubMed

    Javaheri, D S

    2001-04-01

    Due to improved materials, instrumentation, and placement techniques, composite resins have overcome the traditional complications associated with wear resistance, microleakage, sensitivity, and tight anatomical contacts. Composite resins have been utilized with increased frequency for direct posterior restorations capable of satisfying the growing aesthetic expectations of contemporary dental patients. When properly placed, posterior composites can provide successful and predictable restorations. This article presents clinical considerations for the aesthetic conservation of posterior restorations with composite resin materials.

  10. The effect of occlusal forces on restorations.

    PubMed

    Larson, Thomas D

    2014-09-01

    This review will focus on the effect occlusal forces, both normal masticatory force and paranormal bruxing and clenching force, have on various restorative materials and their interaction with the teeth through a variety of bonding mechanisms. Salient physical properties of each of the materials will be reviewed, as well as the effect occlusal force has on restoration durability.

  11. Production possibility frontiers and socioecological tradeoffs for restoration of fire adapted forests.

    PubMed

    Ager, Alan A; Day, Michelle A; Vogler, Kevin

    2016-07-01

    We used spatial optimization to analyze alternative restoration scenarios and quantify tradeoffs for a large, multifaceted restoration program to restore resiliency to forest landscapes in the western US. We specifically examined tradeoffs between provisional ecosystem services, fire protection, and the amelioration of key ecological stressors. The results revealed that attainment of multiple restoration objectives was constrained due to the joint spatial patterns of ecological conditions and socioeconomic values. We also found that current restoration projects are substantially suboptimal, perhaps the result of compromises in the collaborative planning process used by federal planners, or operational constraints on forest management activities. The juxtaposition of ecological settings with human values generated sharp tradeoffs, especially with respect to community wildfire protection versus generating revenue to support restoration and fire protection activities. The analysis and methods can be leveraged by ongoing restoration programs in many ways including: 1) integrated prioritization of restoration activities at multiple scales on public and adjoining private lands, 2) identification and mapping of conflicts between ecological restoration and socioeconomic objectives, 3) measuring the efficiency of ongoing restoration projects compared to the optimal production possibility frontier, 4) consideration of fire transmission among public and private land parcels as a prioritization metric, and 5) finding socially optimal regions along the production frontier as part of collaborative restoration planning. PMID:27033166

  12. Faults in Paleozoic basement and their participation in Alpine deformation of Greater Caucasus – evidences from materials of restored (balanced) sections in folded sedimentary cover

    NASA Astrophysics Data System (ADS)

    Yakovlev, Fedor

    2015-04-01

    Method. As each fold has information about strain, numerous folds (0.1-1 km width) inside of hinterland (stripe about 1000 x 50 km) of Greater Caucasus (GC) allow to restore structure for whole sedimentary cover. Material of 24 detailed sections of 510 km total actual length in three regions was used for restoration of structure. These sections were split on 505 domains as associations of 2-5 folds. Three parameters of morphology were measured in these domains: dip of axial plain, dip of envelope plain, value of shortening as interlimb angle [1, 2, 3]. Because these parameters correlate with ellipsoid (ellipse) of strain for domain, sequence of three kinematic operations allow to restore actual state of domain to pre-folded state (from ellipse to circle): rotation to horizontal position of envelope plain, horizontal simple shear to vertical axial plain and vertical flattening (pure shear). Aggregation of chain of pre-folded domains is forming a pre-folded state of whole section, and it allows to calculate of shortening value. For correct detailing of strain study, 78 "structural cells" were formed by aggregation of 5-10 domains in each cell. Some additional observations and calculations allow to find initial and post-folded thickness of sedimentary cover, depth of cover bottom, virtual position of cover top (amplitude of erosion) for all tectonic cells. The received result for 78 cells allowed to understand the main features of GC structure, to see a distribution of basement top depth, to give behavior pattern of the basement and to find a role of faults in shortening of the basement and of sedimentary cover. Results. Three regions of GC were studied: North-Western Caucasus (NWC) [1], Chiaur tectonic zone in South Ossetia (ChZ) and two zones in South-Eastern Caucasus - Tfan Zone (TZ) and Shakhdag zone (ShZ) [3]. The shortening values for structural cells were found as 49% in average for ShZ (with deviations 37÷62%), 55% for TZ (36÷67%), 57% for ChZ (46÷67%) and

  13. Clinical guidelines for indirect resin restorations.

    PubMed

    Shannon, A

    1997-06-01

    Ongoing advances in adhesive dentistry have made it possible to successfully and predictably bond tooth-supporting restorations using conservative preparation techniques. Improvements in the durability and esthetic properties of tooth-colored restorative materials have also increased the range of available treatment options. However, dentists have been slow to accept both direct and indirect posterior esthetics. This article provides a step-by-step technique for practitioners who choose to treat their patients with indirect resin esthetic restorations. It will not discuss other posterior restorative treatment techniques or materials (i.e. gold, porcelain, amalgam, bonded amalgam, or direct resin).

  14. Guidelines for Direct Adhesive Composite Restoration.

    PubMed

    Society Of Cariology And Endodontology, Chinese Stomatological Association Csa

    2015-01-01

    Direct adhesive composite restoration, a technique to restore tooth defects by bonding composite resin materials, has been widely used in the restoration of dental caries or other tooth defects. Retention of composite resin restoration mainly relies on bonding strength between the materials and dental tissue. The clinical outcomes rely greatly on the regulated clinical practice of dentists. In 2011, the Society of Cariology and Endodontology of Chinese Stomatological Association (CSA) published the 'Practices and evaluation criteria of composite resin bonded restoration (Discussion Version)'. Since then, opinions and comments regarding the 'Discussion Version' have been widely circulated within the Society. The final version of the guideline was based on systematic reviews of scientific literature and requirements for the edit of technical guidelines, and through several rounds of discussions, revisions and supplements. The society recommends this guideline for clinicians to use in their practices, when conducting direct composite restorations.

  15. Posterior restorations--a clinical view.

    PubMed

    Jedynakiewicz, N M; Martin, N

    2001-01-01

    This paper examines the state-of-the-art in the direct restoration of posterior teeth. The existing paradigms for the management of caries are questioned and some existing methods of cavity preparation are reviewed. Dental restorations need to be durable but able to adapt to a changing environment brought about by wear of the adjacent tooth substance and by fatigue processes within the tooth itself. The wear of restorative materials needs to be matched to that of the tooth, otherwise differential loss of either the restorative material or the enamel may destabilize the occlusion. Esthetic instability due to natural darkening of the tooth with age, punctuated by clinical intervention with bleaching procedures, adds a further dimension to the concept of a permanent restoration. Clinical methods that minimize the disruptive effects of dental restorations upon the remaining tooth structure are a continuing challenge.

  16. Fernald restoration: ecologists and engineers integrate restoration and cleanup

    SciTech Connect

    Woods, Eric; Homer, John

    2002-07-15

    As cleanup workers excavate pits and tear down buildings at the Fernald site in southwest Ohio, site ecologists are working side-by-side to create thriving wetlands and develop the early stages of forest, prairie, and savanna ecosystems to restore natural resources that were impacted by years of site operations. In 1998, the U.S. Department of Energy-Fernald Office (DOE-FN) and its cleanup contractor, Fluor Fernald, Inc., initiated several ecological restoration projects in perimeter areas of the site (e.g., areas not used for or impacted by uranium processing or waste management). The projects are part of Fernald's final land use plan to restore natural resources over 904 acres of the 1,050-acre site. Pete Yerace, the DOE-FN Natural Resource Trustee representative is working with the Fernald Natural Resource Trustees in an oversight role to resolve the state of Ohio's 1986 claim against DOE for injuries to natural resources. Fluor Fernald, Inc., and DOE-FN developed the ''Natural Resource Restoration Plan'', which outlines 15 major restoration projects for the site and will restore injured natural resources at the site. In general, Fernald's plan includes grading to maximize the formation of wetlands or expanded floodplain, amending soil where topsoil has been removed during excavation, and establishing native vegetation throughout the site. Today, with cleanup over 35 percent complete and site closure targeted for 2006, Fernald is entering a new phase of restoration that involves heavily remediated areas. By working closely with engineers and cleanup crews, site ecologists can take advantage of remediation fieldwork (e.g., convert an excavated depression into a wetland) and avoid unnecessary costs and duplication. This collaboration has also created opportunities for relatively simple and inexpensive restoration of areas that were discovered during ongoing remediation. To ensure the survival of the plant material in heavily disturbed soils, Fernald will use

  17. Restoring primary anterior teeth: updated for 2014.

    PubMed

    Waggoner, William F

    2015-01-01

    The purpose of this paper was to review the current literature associated with the techniques and materials for the restoration of primary anterior teeth and make clinical recommendations based upon the available literature. A variety of esthetic restorative materials are available to utilize for restoring primary incisors. Awareness of the specific strengths, weakness, and properties of each material can enhance the clinician's ability to make the best choice of selection for each individual situation. Intracoronal restorations of primary teeth may utilize resin composites, glass ionomer cements, resin-modified ionomers, or polyacid-modified resins. Full coronal restoration of primary incisors may be indicated for a number of reasons. Crowns available for restoration of primary incisors include those that are directly bonded onto the tooth, which generally are a resin material, and crowns that are luted onto the tooth and are either some type of stainless steel or zirconia crown. There is insufficient controlled, clinical data to suggest that one type of restoration is superior to another. Operator preferences, esthetic demands by parents, the child's behavior, the amount of tooth structure remaining, and moisture and hemorrhage control are all variables that affect the decision and ultimate outcome of whatever restorative solution is chosen. PMID:25905657

  18. Esthetic restoration of discolored primary incisors.

    PubMed

    Margolis, Fred S

    2005-01-01

    Restoring primary teeth can be a strenuous task for many dentists who would like to have an esthetic, easy-to-use and relatively quick restoration for children. But, the restoration of carious, fractured or discolored primary incisors gives the dentist the satisfaction of knowing that he/she has restored the smile and self-confidence of a growing child. This article describes a technique which is relatively easy and produces a beautiful outcome in a relatively short time. The author has used the technique in hundreds of children for over twenty-five years. Modifications in the technique have been made as newer materials and techniques have evolved. PMID:15739584

  19. Fabrication of a new crown and provisional to an existing removable partial denture.

    PubMed

    Jackson, A D; Butler, C J

    1995-09-01

    A method of fabricating a new crown to an existing removable partial denture is described. A press-form plastic shell made from the diagnostic cast provides the outer contours for the abutment tooth, while an acrylic resin coping is fabricated on a die to provide accurate internal adaptation. The acrylic resin coping is seated on the prepared abutment. Autopolymerizing acrylic resin is mixed and placed in the plastic shell that is then placed in the mouth over the coping, forming the acrylic resin crown pattern. The removable partial prosthesis is fitted over the crown pattern intraorally. The pattern is transferred back to the die, the margins are refined, and the casting is completed and finished, avoiding reduction of the established contours. The same plastic shell is used with tooth-shaded acrylic resin to construct a provisional crown directly in the mouth. This technique allows the patient to wear the removable partial denture while the laboratory procedures are completed.

  20. Overview of the Standing Operating Procedures (SOP) for the Development of Provisional Advisory Levels (PALs)

    SciTech Connect

    Young, Robert; Bast, Cheryl B; Wood, Carol S; Adeshina, Femi; Ross, Robert Hord

    2009-01-01

    Provisional Advisory Levels (PALs) are concentrations in air and drinking water for priority toxic chemicals. This article summarizes the Standing Operating Procedures (SOPs) currently in place for the data-driven development of chemical-specific PALs. To provide consistency and transparency, and to avoid faults of arbitrariness, SOPs were developed for guidance in deriving PAL values. The SOPs for PAL development focus on: 1) data acquisition and analysis, 2) identification of a chemical-specific critical effect, 3) selection of a quantitative point-of-departure (POD), 4) uncertainty analysis and adjustments, 5) exposure duration adjustment and extrapolation, 6) identification of special concerns and issues, and 7) verification, documentation and dissemination of PALs. To avoid uncompromising rigidity in deriving PAL values and to allow for incorporation of new or refined methodologies, the overall procedure is fluid and subject to modification. The purpose of this publication is to provide a summary of these SOPs.

  1. Breaking up is hard to do: the economic impact of provisional funding contingent upon evidence development.

    PubMed

    Mortimer, Duncan; Li, Jing Jing; Watts, Jennifer; Harris, Anthony

    2011-10-01

    Funding contingent upon evidence development (FED) has recently been the subject of some considerable debate in the literature but relatively little has been made of its economic impact. We argue that FED has the potential to shorten the lag between innovation and access but may also (i) crowd-out more valuable interventions in situations in which there is a fixed dedicated budget; or (ii) lead to a de facto increase in the funding threshold and increased expenditure growth in situations in which the programme budget is open-ended. Although FED would typically entail periodic review of provisional or interim listings, it may prove difficult to withdraw funding even at cost/QALY ratios well in excess of current listing thresholds. Further consideration of the design and implementation of FED processes is therefore required to ensure that its introduction yields net benefits over existing processes.

  2. 76 FR 77981 - Build-A-Bear Workshop, Inc., Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-15

    ... COMMISSION Build-A-Bear Workshop, Inc., Provisional Acceptance of a Settlement Agreement and Order AGENCY... Agreement with Build-A-Bear Workshop, Inc., containing a civil penalty of $600,000.00. DATES: Any interested... Agreement 1. In accordance with 16 CFR 1118.20, Build-A-Bear Workshop, Inc. (``Build-A-Bear'') and staff...

  3. 76 FR 48808 - Black & Decker (U.S.) Inc., Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-09

    ... accordance with the terms of 16 CFR 1118.20(e). Published ] below is a provisionally accepted Settlement... sold through retailers nationwide for approximately $70.00. (5) The Grasshog XPs are ``consumer... CPSC staff of what it termed a ``quality'' problem involving the original spool cover but did not...

  4. 75 FR 27736 - Availability for Non-Exclusive, Exclusive, or Partially Exclusive Licensing of U.S. Provisional...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-18

    .... Provisional Patent Application Concerning Two-Stage Evaporative Cooling Method for Protective Clothing...,070 entitled ``Two-Stage Evaporative Cooling Method for Protective Clothing Ensembles,'' filed March... cooling method for use in protective clothing ensembles. Brenda S. Bowen, Army Federal Register...

  5. Between Worlds: A Grounded Theory Study of the Experiences of Provisional Students at a Four-Year Public University

    ERIC Educational Resources Information Center

    Cook, Terry L.

    2009-01-01

    Applicants for college entrance may be deemed able to succeed based on a variety of screening factors: standardized test scores such as ACT or SAT, high school grade point average or completion of college preparatory coursework. Rio Grande University (pseudonym) offered provisional admission to applicants who met all entrance requirements with the…

  6. Provisional standards of radiation safety of flight personnel and passengers in air transport of the civil aviation

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Provisional standards for radiation affecting passenger aircraft are considered. Agencies responsible for seeing that the regulations are enforced are designated while radiation sources and types of radiation are defined. Standard levels of permissible radiation are given and conditions for radiation safety are discussed. Dosimetric equipment on board aircraft is delineated and regulation effective dates are given.

  7. Restoration technology branch

    USGS Publications Warehouse

    ,

    2007-01-01

    The mission of Leetown Science Center (LSC), Restoration Technology Branch (RTB) is to conduct research needed to restore or protect the chemical, physical and biological integrity of desirable aquatic systems.

  8. Enhanced aesthetics with all ceramics restoration

    PubMed Central

    Nayar, Sanjna; Aruna, U.; Bhat, Wasim Manzoor

    2015-01-01

    The demand for the dentist to achieve excellence in esthetics and function has driven modern advances in materials and restoration fabrication. The development of various casting alloys and precise casting systems has contributed to the successful use of metal-based restorations. However, patient requests for more aesthetic and biologically “safe” materials that have led to an increased demand for metal-free restorations. The following case presentation illustrates a successful aesthetic and functional application of this exciting computer-aided design/computer-aided manufacturing-digital zirconia-based system for a natural smile. PMID:26015733

  9. [Marginal leakage in composite resin restorations in posterior teeth. Effect of material, cavity preparation and enamel conditioning at the cervical level].

    PubMed

    Marotta Araujo, R; da Silva Filho, F P; Dias Mendes, A J

    1990-01-01

    The purpose of this "in vitro" study was to investigate the cervical marginal leakage in class II restorations with chemically cured resin (P10) and light-cured resin (P30) in two types of cavities: conventional and adhesive. The effect of acid-etching in this area was also observed. Dentine adhesive Scotchbond was used in all experimental groups. Leakage was evidenced by Rodamina B dye penetration after thermocycling procedure between 10 degrees C and 50 degrees C temperature and analysed by using Zeiss Stereoscopic Magnifying Glass (10 X). According to the results obtained marginal leakage occurred in all experimental groups, with lower percentage for adhesives cavities when enamel acid-etching and light-cured resin P30 was used.

  10. Linking restoration ecology with coastal dune restoration

    NASA Astrophysics Data System (ADS)

    Lithgow, D.; Martínez, M. L.; Gallego-Fernández, J. B.; Hesp, P. A.; Flores, P.; Gachuz, S.; Rodríguez-Revelo, N.; Jiménez-Orocio, O.; Mendoza-González, G.; Álvarez-Molina, L. L.

    2013-10-01

    Restoration and preservation of coastal dunes is urgently needed because of the increasingly rapid loss and degradation of these ecosystems because of many human activities. These activities alter natural processes and coastal dynamics, eliminate topographic variability, fragment, degrade or eliminate habitats, reduce diversity and threaten endemic species. The actions of coastal dune restoration that are already taking place span contrasting activities that range from revegetating and stabilizing the mobile substrate, to removing plant cover and increasing substrate mobility. Our goal was to review how the relative progress of the actions of coastal dune restoration has been assessed, according to the ecosystem attributes outlined by the Society of Ecological Restoration: namely, integrity, health and sustainability and that are derived from the ecological theory of succession. We reviewed the peer reviewed literature published since 1988 that is listed in the ISI Web of Science journals as well as additional references, such as key books. We exclusively focused on large coastal dune systems (such as transgressive and parabolic dunefields) located on natural or seminatural coasts. We found 150 articles that included "coastal dune", "restoration" and "revegetation" in areas such as title, keywords and abstract. From these, 67 dealt specifically with coastal dune restoration. Most of the studies were performed in the USA, The Netherlands and South Africa, during the last two decades. Restoration success has been assessed directly and indirectly by measuring one or a few ecosystem variables. Some ecosystem attributes have been monitored more frequently (ecosystem integrity) than others (ecosystem health and sustainability). Finally, it is important to consider that ecological succession is a desirable approach in restoration actions. Natural dynamics and disturbances should be considered as part of the restored system, to improve ecosystem integrity, health and

  11. Recent trends in esthetic restorations for posterior teeth.

    PubMed

    Dietschi, D; Magne, P; Holz, J

    1994-10-01

    The increase in the demands made by patients for esthetic or metal-free restorations, together with the ever-growing interest shown by the dental profession for tooth-colored materials and techniques, led to the current development of posterior adhesive restorations. This paper reviews critical elements such as adhesion to dental hard tissues as well as current properties of bases/liners, filling materials, and luting materials. A rationale for the successful use of currently available restorative systems is presented.

  12. Iatrogenic Damage to Periodontium by Restorative Treatment Procedures: An Overview

    PubMed Central

    Sirajuddin, Syed; Narasappa, Kumuda M; Gundapaneni, Veenadharini; Chungkham, Sachidananda; Walikar, Ambica S

    2015-01-01

    The regenerative capability found in most other tissues is not possessed by teeth. Hence, enamel or dentin once lost as a result of caries, trauma, wear, and restorative materials must be replaced to restore form and function. Teeth require preparation to receive restorations, and these preparations must be based on fundamental principles from which basic criteria can be developed to help predict the success of restorative treatment. PMID:26312091

  13. Full mouth rehabilitation of a patient with reduced vertical dimension using multiple metal ce ramic restorations.

    PubMed

    Jain, Ashish R; Nallaswamy, Deepak; Ariga, Padma; Philip, Jacob Mathew

    2013-10-01

    Rehabilitation of a patient with severely worn dentition after restoring the vertical dimension is a complex procedure and assessment of the vertical dimension is an important aspect in these cases. This clinical report describes the full mouth rehabilitation of a patient who was clinically monitored to evaluate the adaptation to a removable occlusal splint to restore vertical dimension for a period 1 month and provisional restorations to determine esthetic and functional outcome for a period of 3 months. It is necessary to recognizing that form follows function and that anterior teeth play a vital role in the maintenance of oral health. Confirmation of tolerance to changes in the vertical dimension of occlusion (VDO) is of paramount importance. Articulated study casts and a diagnostic wax-up can provide important information for the evaluation of treatment options. Alteration of the VDO should be conservative and should not be changed without careful consideration.

  14. Full mouth rehabilitation of a patient with reduced vertical dimension using multiple metal ce ramic restorations

    PubMed Central

    Jain, Ashish R; Nallaswamy, Deepak; Ariga, Padma; Philip, Jacob Mathew

    2013-01-01

    Rehabilitation of a patient with severely worn dentition after restoring the vertical dimension is a complex procedure and assessment of the vertical dimension is an important aspect in these cases. This clinical report describes the full mouth rehabilitation of a patient who was clinically monitored to evaluate the adaptation to a removable occlusal splint to restore vertical dimension for a period 1 month and provisional restorations to determine esthetic and functional outcome for a period of 3 months. It is necessary to recognizing that form follows function and that anterior teeth play a vital role in the maintenance of oral health. Confirmation of tolerance to changes in the vertical dimension of occlusion (VDO) is of paramount importance. Articulated study casts and a diagnostic wax-up can provide important information for the evaluation of treatment options. Alteration of the VDO should be conservative and should not be changed without careful consideration. PMID:24403804

  15. [The stamp technique for direct composite restoration].

    PubMed

    Perrin, Philippe; Zimmerli, Brigitte; Jacky, Daniel; Lussi, Adrian; Helbling, Christoph; Ramseyer, Simon

    2013-01-01

    The indications for direct resin composite restorations are nowadays extended due to the development of modern resin materials with improved material properties. However, there are still some difficulties regarding handling of resin composite material, especially in large restorations. The reconstruction of a functional and individual occlusion is difficult to achieve with direct application techniques. The aim of the present publication was to introduce a new "stamp"-technique for placing large composite restorations. The procedure of this "stamp"-technique is presented by three typical indications: large single-tooth restoration, occlusal rehabilitation of a compromised occlusal surface due to erosions and direct fibre-reinforced fixed partial denture. A step-by-step description of the technique and clinical figures illustrates the method. Large single-tooth restorations can be built-up with individual, two- piece silicone stamps. Large occlusal abrasive and/or erosive defects can be restored by copying the wax-up from the dental technician using the "stamp"-technique. Even fiber-reinforced resin-bonded fixed partial dentures can be formed with this intraoral technique with more precision and within a shorter treatment time. The presented "stamp"-technique facilitates the placement of large restoration with composite and can be recommended for the clinical use.

  16. Tooth-colored CAD/CAM monolithic restorations.

    PubMed

    Reich, S

    2015-01-01

    A monolithic restoration (also known as a full contour restoration) is one that is manufactured from a single material for the fully anatomic replacement of lost tooth structure. Additional staining (followed by glaze firing if ceramic materials are used) may be performed to enhance the appearance of the restoration. For decades, monolithic restoration has been the standard for inlay and partial crown restorations manufactured by both pressing and computer-aided design and manufacturing (CAD/CAM) techniques. A limited selection of monolithic materials is now available for dental crown and bridge restorations. The IDS (2015) provided an opportunity to learn about and evaluate current trends in this field. In addition to new developments, established materials are also mentioned in this article to complete the picture. In line with the strategic focus of the IJCD, the focus here is naturally on CAD/CAM materials. PMID:26110926

  17. Tooth-colored CAD/CAM monolithic restorations.

    PubMed

    Reich, S

    2015-01-01

    A monolithic restoration (also known as a full contour restoration) is one that is manufactured from a single material for the fully anatomic replacement of lost tooth structure. Additional staining (followed by glaze firing if ceramic materials are used) may be performed to enhance the appearance of the restoration. For decades, monolithic restoration has been the standard for inlay and partial crown restorations manufactured by both pressing and computer-aided design and manufacturing (CAD/CAM) techniques. A limited selection of monolithic materials is now available for dental crown and bridge restorations. The IDS (2015) provided an opportunity to learn about and evaluate current trends in this field. In addition to new developments, established materials are also mentioned in this article to complete the picture. In line with the strategic focus of the IJCD, the focus here is naturally on CAD/CAM materials.

  18. Utilization of ceromer inlays/onlays for replacement of amalgam restorations.

    PubMed

    Koczarski, M J

    1998-05-01

    Fiber-reinforced Ceromer technology has been recommended for a variety of restorations, including inlays/onlays, crowns and bridges, and direct restorations. Ideal restorative dental materials must exhibit adequate physical properties and fit, as well as ease and predictability of fabrication and repair. The Ceromer restorative material combines the positive attributes of indirect composite restorations, feldspathic ceramics, and cast-gold restorations. This article reviews the material properties and aesthetic characteristics inherent to Ceromers, as well as the appropriate preparation and adhesive techniques for inlay/onlay restorations.

  19. Physiologically-based pharmacokinetic model for Fentanyl in support of the development of Provisional Advisory Levels

    SciTech Connect

    Shankaran, Harish; Adeshina, Femi; Teeguarden, Justin G.

    2013-12-15

    Provisional Advisory Levels (PALs) are tiered exposure limits for toxic chemicals in air and drinking water that are developed to assist in emergency responses. Physiologically-based pharmacokinetic (PBPK) modeling can support this process by enabling extrapolations across doses, and exposure routes, thereby addressing gaps in the available toxicity data. Here, we describe the development of a PBPK model for Fentanyl – a synthetic opioid used clinically for pain management – to support the establishment of PALs. Starting from an existing model for intravenous Fentanyl, we first optimized distribution and clearance parameters using several additional IV datasets. We then calibrated the model using pharmacokinetic data for various formulations, and determined the absorbed fraction, F, and time taken for the absorbed amount to reach 90% of its final value, t90. For aerosolized pulmonary Fentanyl, F = 1 and t90 < 1 min indicating complete and rapid absorption. The F value ranged from 0.35 to 0.74 for oral and various transmucosal routes. Oral Fentanyl was absorbed the slowest (t90 ∼ 300 min); the absorption of intranasal Fentanyl was relatively rapid (t90 ∼ 20–40 min); and the various oral transmucosal routes had intermediate absorption rates (t90 ∼ 160–300 min). Based on these results, for inhalation exposures, we assumed that all of the Fentanyl inhaled from the air during each breath directly, and instantaneously enters the arterial circulation. We present model predictions of Fentanyl blood concentrations in oral and inhalation scenarios relevant for PAL development, and provide an analytical expression that can be used to extrapolate between oral and inhalation routes for the derivation of PALs. - Highlights: • We develop a Fentanyl PBPK model for relating external dose to internal levels. • We calibrate the model to oral and inhalation exposures using > 50 human datasets. • Model predictions are in good agreement with the available

  20. Political and Economic Geomorphology: The Effect of Market Forces on Stream Restoration Designs

    NASA Astrophysics Data System (ADS)

    Singh, J.; Doyle, M. W.; Lave, R.; Robertson, M.

    2013-12-01

    disproportionately located in very small catchments, and designs seemed to be only marginally related to the location of the stream. Provisional findings also indicate that the differences between mitigation and non-mitigation designs were less than expected. Interview data support this observation; design engineers and entrepreneurial credit providers (i.e., mitigation bankers) apparently viewed the design process as a somewhat standard, non-malleable practice. Sustaining long-term relationships with regulators, who must approve the sale of restored stream credits, was seen as critically important rather than the marginal gains to be made by manipulating particular stream designs to glean more credits. Overall, preliminary results demonstrate that regulatory frameworks, economic incentives and social relationships played a key role in driving stream restoration design in North Carolina, often homogenizing design practices and limiting ';credit chasing.'

  1. The bionic man: restoring mobility.

    PubMed

    Craelius, William

    2002-02-01

    Bionics engineers are making increasingly bold and successful use of their tools to restore mobility to persons with missing or nonfunctional limbs. These tools include the latest materials, minielectronics and megacomputers, advanced robotic mechanisms, and algorithms. With crucial help from their pioneering users, they are learning how and where the residual sensorimotor system can be tapped in order to transmit its intents to replacement or reactivated body parts.

  2. Examples of model-free implant restorations using Cerec inLab 4.0 software.

    PubMed

    Reich, S; Schley, J; Kern, T; Fiedler, K; Wolfart, S

    2012-01-01

    This case report demonstrates two ways to fabricate model-free implant restorations with the Cerec inLab 4.0 software. Because the patient, a woman with a history of periodontal disease, did not wish to have a removable partial denture, implant therapy was planned for the restoration of her edentulous areas 14/15 and 24/25. In addition, the restoration was to provide functional relief of the natural maxillary anterior teeth. The two implants for the first quadrant were planned as single-tooth restorations. Each was designed as a full contour implant supra-structure using the Cerec Biogeneric abutment design technique. After completing the design phase, each restoration proposal was split into two parts: a zirconia abutment and a lithium disilicate crown. For the restoration of the second quadrant, custom 20-degree-angled abutments were individualized and acquired with the Cerec camera. A block crown was then designed, milled in burn-out acrylic resin, and fabricated from a lithium disilicate glass-ceramic ingot according to the press ceramic technique. Additionally methods of provisional restorations are discussed.

  3. Ecological restoration of litter in mined areas

    NASA Astrophysics Data System (ADS)

    Teresinha Gonçalves Bizuti, Denise; Nino Diniz, Najara; Schweizer, Daniella; de Marchi Soares, Thaís; Casagrande, José Carlos; Henrique Santin Brancalion, Pedro

    2016-04-01

    The success of ecological restoration projects depends on going monitoring of key ecological variables to determine if a desired trajectory has been established and, in the case of mining sites, nutrient cycling recovery plays an utmost importance. This study aimed to quantify and compare the annual litter production in native forests, and in restoration sites established in bauxite mines. We collected samples in 6 native forest remnants and 6 year-old restoration sites every month for a period of one year, in the city of Poços de Caldas/MG, SE Brazil. 120 wire collectors were used (0,6x0,6) and suspended 30cm above the soil surface. The material was dried until constant weight, weighed and fractionated in leaves, branches and reproductive material. The average annual litter production was 2,6 Mg ha-1 in native forests and 2,1 in forest in restoration sites, differing statistically. Litter production was higher in the rainy season, especially in September. Among the litter components, the largest contributor to total production was the fraction leaves, with 55,4% of the total dry weight of material collected, followed by reproductive material which contributed 24,5% and branches, with 20%. We conclude that the young areas in restoration process already restored important part, but still below the production observed in native areas.

  4. Provisional Tic Disorder: What to tell parents when their child first starts ticcing

    PubMed Central

    Black, Kevin J; Black, Elizabeth Rose; Greene, Deanna J.; Schlaggar, Bradley L.

    2016-01-01

    The child with recent onset of tics is a common patient in a pediatrics or child neurology practice. If the child’s first tic was less than a year in the past, the diagnosis is usually Provisional Tic Disorder (PTD). Published reviews by experts reveal substantial consensus on prognosis in this situation: the tics will almost always disappear in a few months, having remained mild while they lasted. Surprisingly, however, the sparse existing data may not support these opinions. PTD may have just as much importance for science as for clinical care. It provides an opportunity to prospectively observe the spontaneous remission of tics. Such prospective studies may aid identification of genes or biomarkers specifically associated with remission rather than onset of tics. A better understanding of tic remission may also suggest novel treatment strategies for Tourette syndrome, or may lead to secondary prevention of tic disorders. This review summarizes the limited existing data on the epidemiology, phenomenology, and outcome of PTD, highlights areas in which prospective study is sorely needed, and proposes that tic disorders may completely remit much less often than is generally believed. PMID:27158458

  5. Provisional Tic Disorder: What to tell parents when their child first starts ticcing.

    PubMed

    Black, Kevin J; Black, Elizabeth Rose; Greene, Deanna J; Schlaggar, Bradley L

    2016-01-01

    The child with recent onset of tics is a common patient in a pediatrics or child neurology practice. If the child's first tic was less than a year in the past, the diagnosis is usually Provisional Tic Disorder (PTD). Published reviews by experts reveal substantial consensus on prognosis in this situation: the tics will almost always disappear in a few months, having remained mild while they lasted. Surprisingly, however, the sparse existing data may not support these opinions. PTD may have just as much importance for science as for clinical care. It provides an opportunity to prospectively observe the spontaneous remission of tics. Such prospective studies may aid identification of genes or biomarkers specifically associated with remission rather than onset of tics. A better understanding of tic remission may also suggest novel treatment strategies for Tourette syndrome, or may lead to secondary prevention of tic disorders. This review summarizes the limited existing data on the epidemiology, phenomenology, and outcome of PTD, highlights areas in which prospective study is sorely needed, and proposes that tic disorders may completely remit much less often than is generally believed. PMID:27158458

  6. En Route Descent Advisor Multi-Sector Planning Using Active and Provisional Controller Plans

    NASA Technical Reports Server (NTRS)

    Vivona, Robert; Green, Steven

    2003-01-01

    As decision support tools are developed to support controllers in complex air traffic control environments, new approaches to maintaining situation awareness and managing traffic planning must be developed to handle the ever-increasing amounts of alerting and advisory data. Within high-density metering and other environments where flight path changes are the rule, not the exception, and where interactions between these changes are required, current trial planning approaches are limited by potential increases in workload. The Enroute Descent Advisor (EDA) is a set of decision support tool capabilities for managing high-density en route traffic subject to metering restrictions. The EDA system s novel approach builds aircraft plans from combinations of user intent data and builds controller plans from combinations of aircraft plans to effectively maintain situation awareness during traffic planning. By maintaining both active (current) and provisional (proposed) controller plans, EDA supports controllers in coordinated traffic planning both within and between sectors. Ultimately, EDA s multi-sector planning approach will facilitate a transition from current sector-oriented operations to a new trajectory-oriented paradigm, enabling new levels of efficiency and collaboration in air traffic control.

  7. Soft Tissue Augmentation Techniques in Implants Placed and Provisionalized Immediately: A Systematic Review.

    PubMed

    Rojo, Rosa; Prados-Frutos, Juan Carlos; Manchón, Ángel; Rodríguez-Molinero, Jesús; Sammartino, Gilberto; Calvo Guirado, José Luis; Gómez-de Diego, Rafael

    2016-01-01

    The aim of this study was to evaluate the effectiveness of techniques for soft tissue augmentation in the placement of immediate implants with and without provisionalization and to assess the quality of the reports in the literature. Randomized clinical trials, prospective clinical trials, and case series were included in this review. Clinical questions were formulated and organised according to the PICOS strategy. An electronic search was performed in PubMed, Cochrane Central Register of Controlled Trials, Scopus, and ISI Web up until June 2016. Interexaminer agreement on eligibility (k = 0.842; p = 0.103) and quality (k = 0.933; p < 0.001) was high. Methodological approaches were assessed using criteria based on design related forms designed by the Dutch Cochrane Collaboration. Finally, 14 papers were identified. In two studies, the implant survival was 90%; for the rest of the studies it was 100%. All studies reported favourable aesthetic, biological, and radiographic outcomes. Surgical and biomechanical complications of this technique were not relevant. This technique effectively compensates for the expected loss of volume of the oral soft tissues and maintains high success rates with good aesthetic results over time. PMID:27517046

  8. Provisional Tic Disorder: What to tell parents when their child first starts ticcing.

    PubMed

    Black, Kevin J; Black, Elizabeth Rose; Greene, Deanna J; Schlaggar, Bradley L

    2016-01-01

    The child with recent onset of tics is a common patient in a pediatrics or child neurology practice. If the child's first tic was less than a year in the past, the diagnosis is usually Provisional Tic Disorder (PTD). Published reviews by experts reveal substantial consensus on prognosis in this situation: the tics will almost always disappear in a few months, having remained mild while they lasted. Surprisingly, however, the sparse existing data may not support these opinions. PTD may have just as much importance for science as for clinical care. It provides an opportunity to prospectively observe the spontaneous remission of tics. Such prospective studies may aid identification of genes or biomarkers specifically associated with remission rather than onset of tics. A better understanding of tic remission may also suggest novel treatment strategies for Tourette syndrome, or may lead to secondary prevention of tic disorders. This review summarizes the limited existing data on the epidemiology, phenomenology, and outcome of PTD, highlights areas in which prospective study is sorely needed, and proposes that tic disorders may completely remit much less often than is generally believed.

  9. Provisional Matrix Deposition in Hemostasis and Venous Insufficiency: Tissue Preconditioning for Nonhealing Venous Ulcers

    PubMed Central

    Parker, Tony J.; Broadbent, James A.; McGovern, Jacqui A.; Broszczak, Daniel A.; Parker, Christina N.; Upton, Zee

    2015-01-01

    Significance: Chronic wounds represent a major burden on global healthcare systems and reduce the quality of life of those affected. Significant advances have been made in our understanding of the biochemistry of wound healing progression. However, knowledge regarding the specific molecular processes influencing chronic wound formation and persistence remains limited. Recent Advances: Generally, healing of acute wounds begins with hemostasis and the deposition of a plasma-derived provisional matrix into the wound. The deposition of plasma matrix proteins is known to occur around the microvasculature of the lower limb as a result of venous insufficiency. This appears to alter limb cutaneous tissue physiology and consequently drives the tissue into a ‘preconditioned’ state that negatively influences the response to wounding. Critical Issues: Processes, such as oxygen and nutrient suppression, edema, inflammatory cell trapping/extravasation, diffuse inflammation, and tissue necrosis are thought to contribute to the advent of a chronic wound. Healing of the wound then becomes difficult in the context of an internally injured limb. Thus, interventions and therapies for promoting healing of the limb is a growing area of interest. For venous ulcers, treatment using compression bandaging encourages venous return and improves healing processes within the limb, critically however, once treatment concludes ulcers often reoccur. Future Directions: Improved understanding of the composition and role of pericapillary matrix deposits in facilitating internal limb injury and subsequent development of chronic wounds will be critical for informing and enhancing current best practice therapies and preventative action in the wound care field. PMID:25785239

  10. Soft Tissue Augmentation Techniques in Implants Placed and Provisionalized Immediately: A Systematic Review

    PubMed Central

    Prados-Frutos, Juan Carlos; Manchón, Ángel; Rodríguez-Molinero, Jesús; Sammartino, Gilberto; Calvo Guirado, José Luis; Gómez-de Diego, Rafael

    2016-01-01

    The aim of this study was to evaluate the effectiveness of techniques for soft tissue augmentation in the placement of immediate implants with and without provisionalization and to assess the quality of the reports in the literature. Randomized clinical trials, prospective clinical trials, and case series were included in this review. Clinical questions were formulated and organised according to the PICOS strategy. An electronic search was performed in PubMed, Cochrane Central Register of Controlled Trials, Scopus, and ISI Web up until June 2016. Interexaminer agreement on eligibility (k = 0.842; p = 0.103) and quality (k = 0.933; p < 0.001) was high. Methodological approaches were assessed using criteria based on design related forms designed by the Dutch Cochrane Collaboration. Finally, 14 papers were identified. In two studies, the implant survival was 90%; for the rest of the studies it was 100%. All studies reported favourable aesthetic, biological, and radiographic outcomes. Surgical and biomechanical complications of this technique were not relevant. This technique effectively compensates for the expected loss of volume of the oral soft tissues and maintains high success rates with good aesthetic results over time. PMID:27517046

  11. Watershed Restoration Project

    SciTech Connect

    Julie Thompson; Betsy Macfarlan

    2007-09-27

    In 2003, the U.S. Department of Energy issued the Eastern Nevada Landscape Coalition (ENLC) funding to implement ecological restoration in Gleason Creek and Smith Valley Watersheds. This project was made possible by congressionally directed funding that was provided through the US Department of Energy, Energy Efficiency and Renewable Energy, Office of the Biomass Program. The Ely District Bureau of Land Management (Ely BLM) manages these watersheds and considers them priority areas within the Ely BLM district. These three entities collaborated to address the issues and concerns of Gleason Creek and Smith Valley and prepared a restoration plan to improve the watersheds’ ecological health and resiliency. The restoration process began with watershed-scale vegetation assessments and state and transition models to focus on restoration sites. Design and implementation of restoration treatments ensued and were completed in January 2007. This report describes the restoration process ENLC undertook from planning to implementation of two watersheds in semi-arid Eastern Nevada.

  12. Ceramics as biomaterials for dental restoration.

    PubMed

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

    2008-11-01

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

  13. 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

  14. Hepatitis B Virus Screening for Patients With Cancer Before Therapy: American Society of Clinical Oncology Provisional Clinical Opinion Update

    PubMed Central

    Hwang, Jessica P.; Somerfield, Mark R.; Alston-Johnson, Devena E.; Cryer, Donna R.; Feld, Jordan J.; Kramer, Barnett S.; Sabichi, Anita L.; Wong, Sandra L.; Artz, Andrew S.

    2015-01-01

    Purpose This updated provisional clinical opinion presents a revised opinion based on American Society of Clinical Oncology panel consensus in the context of an evolving database. Context Despite the 2010 provisional clinical opinion recommendation, there is still evidence of suboptimal hepatitis B virus (HBV) screening among patients at high risk for HBV infection or HBV reactivation after chemotherapy. This updated provisional clinical opinion introduces a risk-adaptive strategy to identify and treat patients with HBV infection to reduce their risk of HBV reactivation. Provisional Clinical Opinion Medical providers should screen by testing patients for HBV infection before starting anti-CD20 therapy or hematopoietic cell transplantation. Providers should also screen patients with risk factors for HBV infection. Screening should include both hepatitis B surface antigen (HBsAg) and hepatitis B core antibody (anti-HBc), because reactivation can occur in patients who are HBsAg positive/anti-HBc positive or HBsAg negative/anti-HBc positive. Either total anti-HBc or anti-HBc immunoglobulin G (not immunoglobulin M) test should be used. Clinicians should start antiviral therapy for HBsAg-positive/anti-HBc–positive patients before or contemporaneously with cancer therapy and monitor HBsAg-negative/anti-HBc–positive patients for reactivation with HBV DNA and ALT levels, promptly starting antivirals if reactivation occurs. Clinicians can initiate antivirals for HBsAg-negative/anti-HBc–positive patients anticipating cancer therapies associated with a high risk of reactivation, or they can monitor HBV DNA and ALT levels and initiate on-demand antivirals. For patients who neither have HBV risk factors nor anticipate cancer therapy associated with a high risk of reactivation, current evidence does not support HBV screening before initiation of cancer therapy. Two panel members provided a minority viewpoint, involving a strategy of universal HBsAg and selective anti

  15. Atomic Oxygen Used to Restore Artworks

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A.; Miller, Sharon K.

    2004-01-01

    Techniques developed at the NASA Glenn Research Center to produce atomic oxygen in order to simulate the low-Earth-orbit environment for spacecraft materials testing can also be applied in the field of art restoration. Defaced or fire-damaged artwork can be treated with atomic oxygen to remove the damage and enable restoration that could not be accomplished with conventional methods. The process has been patented (U.S. Patents 5,560,781 and 5,693,241) and has been used to restore several works of art.

  16. Achieving functional restorations utilizing a new Ceromer system.

    PubMed

    Trinkner, T

    1997-01-01

    The advent of pressed ceramic restorations (IPS Empress, Ivoclar Williams, Amherst, NY) has driven dental therapy to continuously strive for more aesthetic and functional materials. The dental profession requires restorations to exhibit strength, natural color, wear resistance, marginal integrity, and ease of fabrication in the restorative therapies selected. With the introduction of a new ceromer and fiber-reinforced composite (FRC) system (Targis System, Ivoclar Williams, Amherst, NY), the replacement of a single tooth or multiple teeth with a FRC, metal-free bridge is now a suitable alternative to conventional dental therapy. This presentation will review the clinical protocol, material properties, and aesthetic characteristics of this new generation of restorative material.

  17. Predictors for Side Branch Failure During Provisional Strategy of Coronary Intervention for Bifurcation Lesions (from the Korean Bifurcation Registry).

    PubMed

    Seo, Jae-Bin; Shin, Dong-Ho; Park, Kyung Woo; Koo, Bon-Kwon; Gwon, Hyeon-Cheol; Jeong, Myung-Ho; Seong, In-Whan; Rha, Seung Woon; Yang, Ju-Young; Park, Seung-Jung; Yoon, Jung Han; Han, Kyoo-Rok; Park, Jong-Sun; Hur, Seung-Ho; Tahk, Seung-Jea; Kim, Hyo-Soo

    2016-09-15

    The most favored strategy for bifurcation lesion is stenting main vessel with provisional side branch (SB) stenting. This study was performed to elucidate predictors for SB failure during this provisional strategy. The study population was patients from 16 centers in Korea who underwent drug-eluting stent implantation for bifurcation lesions with provisional strategy (1,219 patients and 1,236 lesions). On multivariate analysis, the independent predictors for SB jailing after main vessel stenting were SB calcification, large SB reference diameter, severe stenosis of SB, and not taking clopidogrel. Regarding SB compromise, however, the independent predictors were true bifurcation lesion and small SB reference diameter, whereas possible predictors were parent vessel thrombus and parent vessel total occlusion. In addition, SB predilation helps us to get favorable SB outcome. The diameter of SB ostium after main vessel stenting became similar between severe SB lesions treated with predilation and mild SB lesions not treated with predilation. In conclusion, SB calcification, less clopidogrel use, large SB reference diameter, and high SB diameter stenosis are independent predictors for SB jailing, and true bifurcation and small SB reference diameter are independent predictors for SB compromise after main vessel stenting. PMID:27523437

  18. A new matrix in esthetic posterior restorations.

    PubMed

    Rovatti, L; Cavalleri, G; Dallari, A

    1998-03-01

    Using composite resins in posterior esthetic restorations has become more acceptable in recent years as a result of improvements in materials. For this reason, innovative products such as Luciwedge and the SuperMat System have gained the attention of many practitioners. SuperMat, an improved translucent matrix, offers a new approach to matrices for use with multimaterial fillings. It makes the procedure easier and offers many other advantages, particularly in composite-compomer restorations.

  19. A direct approach to restore anterior teeth.

    PubMed

    Denehy, G E

    2000-11-01

    When selecting the correct treatment for a patient with anterior esthetic problems, the dentist must choose between direct and indirect procedures. With situations allowing conservative treatment, direct resin restoration should be given strong consideration. Advances in materials and techniques that can positively affect this choice include pre-restorative bleaching procedures, new bonding agents, and new highly esthetic direct resin systems. A procedure is described to maximize esthetics and minimize finishing time during direct resin placement.

  20. Restoring the smile: Inexpensive biologic restorations

    PubMed Central

    Mittal, Neeti P.

    2014-01-01

    Extensive breakdown of primary teeth to the cervical level and their loss in very young children is not uncommon. Owing to increasing concerns over self-appearance, due considerations to esthetic aspects in addition to restoring function are necessary aspects of rehabilitation of mutilated teeth to help children grow into a psychologically balanced personality. The present article describes rehabilitation of grossly decayed teeth with biologic restorations such as dentine posts, dentine post and core and biologic shell crown. This treatment modality provided a cost-effective esthetic solution. PMID:25097656

  1. Functional and aesthetic guidelines for stress-reduced direct posterior composite restorations.

    PubMed

    Deliperi, S

    2012-01-01

    Amalgam has been used in the restoration of structurally compromised posterior teeth for many years. When placing large amalgam restorations, replacement of weak cusps with restorative material is recommended to prevent tooth fracture. This recommendation can be modified with new guidelines using modern adhesive techniques. Semidirect and indirect inlay/onlay composite restorations have progressively replaced amalgam restorations over the past 20 years. Lately, single visit direct resin-bonded composite (RBC) restorations have also been used as a viable alternative to conventional indirect restorations. This paper is intended to introduce a step-by-step protocol for the direct restoration of structurally compromised posterior teeth using RBCs with stress-reducing protocols.

  2. Three-year Clinical Evaluation of Different Restorative Resins in Class I Restorations.

    PubMed

    Yazici, Ar; Ustunkol, I; Ozgunaltay, G; Dayangac, B

    2013-12-19

    SUMMARY The aim of the present study was to evaluate the three-year clinical performance of a nanofilled resin composite, a packable resin composite, and silorane-based resin restorations in Class I occlusal cavities. Twenty-eight patients with at least three similar-sized occlusal lesions in molar teeth participated in the study. A total of 84 Class I occlusal restorations were placed: 28 with nanofilled resin composite (Filtek Supreme), 28 with packable resin composite (P60), and 28 with silorane-based resin (Filtek Silorane). Filtek Supreme and P60 were used with their respective etch-and-rinse adhesive system, Adper Single Bond 2, and Filtek Silorane was used with its respective self-etch adhesive, Filtek Silorane Adhesive. All restorations were placed by the same operator. The restorations were evaluated at baseline, at six months, and annually for three years according to modified US Public Health Service criteria by two calibrated examiners who did not know which restorative resin had been used. The three restorative materials for each category were compared using the χ(2) test at a significance level of 0.05. Cochran's Q test was used to compare the changes across the five time points for each restorative material. McNemar's test followed by Bonferroni adjustment was used when significance differences were found. At the end of the three years, 60 restorations were evaluated in 20 patients, with a recall rate of 71.4%. The retention rate was 100% for all restorative resins. Eight restorations from the P60 group, ten from the Filtek Supreme group, and nine from the Filtek Silorane group were rated Bravo for marginal discoloration. For marginal adaptation, three P60, five Filtek Supreme, and 11 Filtek Silorane restorations were rated Bravo. No statistically significant differences in overall clinical performance were found between the restorative materials except for marginal adaptation. P60 showed the best marginal adaptation at the end of the three years

  3. Three-year clinical evaluation of different restorative resins in class I restorations.

    PubMed

    Yazici, A R; Ustunkol, I; Ozgunaltay, G; Dayangac, B

    2014-01-01

    The aim of the present study was to evaluate the three-year clinical performance of a nanofilled resin composite, a packable resin composite, and silorane-based resin restorations in Class I occlusal cavities. Twenty-eight patients with at least three similar-sized occlusal lesions in molar teeth participated in the study. A total of 84 Class I occlusal restorations were placed: 28 with nanofilled resin composite (Filtek Supreme), 28 with packable resin composite (P60), and 28 with silorane-based resin (Filtek Silorane). Filtek Supreme and P60 were used with their respective etch-and-rinse adhesive system, Adper Single Bond 2, and Filtek Silorane was used with its respective self-etch adhesive, Filtek Silorane Adhesive. All restorations were placed by the same operator. The restorations were evaluated at baseline, at six months, and annually for three years according to modified US Public Health Service criteria by two calibrated examiners who did not know which restorative resin had been used. The three restorative materials for each category were compared using the χ (2) test at a significance level of 0.05. Cochran's Q test was used to compare the changes across the five time points for each restorative material. McNemar's test followed by Bonferroni adjustment was used when significance differences were found. At the end of the three years, 60 restorations were evaluated in 20 patients, with a recall rate of 71.4%. The retention rate was 100% for all restorative resins. Eight restorations from the P60 group, ten from the Filtek Supreme group, and nine from the Filtek Silorane group were rated Bravo for marginal discoloration. For marginal adaptation, three P60, five Filtek Supreme, and 11 Filtek Silorane restorations were rated Bravo. No statistically significant differences in overall clinical performance were found between the restorative materials except for marginal adaptation. P60 showed the best marginal adaptation at the end of the three years. No

  4. Survival of ART restorations assessed using selected FDI and modified ART restoration criteria.

    PubMed

    Farag, Abeer; van der Sanden, Wil J M; Abdelwahab, Hisran; Frencken, Jo E

    2011-06-01

    A new set of criteria for assessing the quality of restorations using modern restorative materials, named FDI criteria, was recently introduced. This study tested the null hypothesis that there is no significant difference in survival estimate percentages of ART restorations assessed using selected FDI and modified ART criteria after 1 and 5 years. One operator placed a total of 60 class I and 30 Class II high-viscosity glass-ionomer ART restorations in ninety 14- to 15-year-olds. Two calibrated and independent evaluators using both criteria evaluated restorations on diestone replicas at baseline and after 1 and 5 years. Statistical analyses were done using the Kaplan-Meier method and log-rank test. The survival results of ART restorations assessed using both sets of criteria after 1 and 5 years (p = 0.27) did not differ significantly. Three ART restorations were assessed as failures according to the ART criteria, while they were assessed as survived using the FDI criteria. We conclude that the modified ART criteria enable reliable assessment of ART restorations in permanent teeth from diestone replicas and that there was no significant difference in survival estimates of ART restorations assessed using both sets of criteria. The null hypothesis was accepted.

  5. Utah Paiute Tribal Restoration.

    ERIC Educational Resources Information Center

    Turner, Allen C.

    The Paiute Indian Tribe of Utah Restoration Act (1980) restored federal recognition of the tribe after a quarter century of ambiguous political status, and resulted in significant improvements of educational status of tribal members and intensification of the political presence of Southern Paiutes. Following the Paiute Indian Termination Act…

  6. Power system restoration issues

    SciTech Connect

    Adibi, M.M. ); Kafka, R.J. )

    1991-04-01

    This article describes some of the problems encountered in the three phases of power system restoration (PSR). The three phases of PSR are: Planning for restart and reintegration of the bulk power supply; Actions during system degradation for saving and retaining critical sources of power; Restoration when the power system has stabilized at some degraded level.

  7. Gill's 'History' restored

    NASA Astrophysics Data System (ADS)

    Hurn, Mark

    2009-06-01

    Note about the restoration of the copy of Sir David Gill's 'A History and Description of the Royal Observatory, Cape of Good Hope' in the Library of the Institute of Astronomy, Cambridge. The book was restored with funds provided by the SHA in thanks for facilities for meetings provided to the Institute.

  8. Physiologically-based pharmacokinetic model for Fentanyl in support of the development of Provisional Advisory Levels.

    PubMed

    Shankaran, Harish; Adeshina, Femi; Teeguarden, Justin G

    2013-12-15

    Provisional Advisory Levels (PALs) are tiered exposure limits for toxic chemicals in air and drinking water that are developed to assist in emergency responses. Physiologically-based pharmacokinetic (PBPK) modeling can support this process by enabling extrapolations across doses, and exposure routes, thereby addressing gaps in the available toxicity data. Here, we describe the development of a PBPK model for Fentanyl - a synthetic opioid used clinically for pain management - to support the establishment of PALs. Starting from an existing model for intravenous Fentanyl, we first optimized distribution and clearance parameters using several additional IV datasets. We then calibrated the model using pharmacokinetic data for various formulations, and determined the absorbed fraction, F, and time taken for the absorbed amount to reach 90% of its final value, t90. For aerosolized pulmonary Fentanyl, F=1 and t90<1 min indicating complete and rapid absorption. The F value ranged from 0.35 to 0.74 for oral and various transmucosal routes. Oral Fentanyl was absorbed the slowest (t90~300 min); the absorption of intranasal Fentanyl was relatively rapid (t90~20-40 min); and the various oral transmucosal routes had intermediate absorption rates (t90~160-300 min). Based on these results, for inhalation exposures, we assumed that all of the Fentanyl inhaled from the air during each breath directly, and instantaneously enters the arterial circulation. We present model predictions of Fentanyl blood concentrations in oral and inhalation scenarios relevant for PAL development, and provide an analytical expression that can be used to extrapolate between oral and inhalation routes for the derivation of PALs.

  9. Provisional in-silico biopharmaceutics classification (BCS) to guide oral drug product development.

    PubMed

    Wolk, Omri; Agbaria, Riad; Dahan, Arik

    2014-01-01

    The main objective of this work was to investigate in-silico predictions of physicochemical properties, in order to guide oral drug development by provisional biopharmaceutics classification system (BCS). Four in-silico methods were used to estimate LogP: group contribution (CLogP) using two different software programs, atom contribution (ALogP), and element contribution (KLogP). The correlations (r(2)) of CLogP, ALogP and KLogP versus measured LogP data were 0.97, 0.82, and 0.71, respectively. The classification of drugs with reported intestinal permeability in humans was correct for 64.3%-72.4% of the 29 drugs on the dataset, and for 81.82%-90.91% of the 22 drugs that are passively absorbed using the different in-silico algorithms. Similar permeability classification was obtained with the various in-silico methods. The in-silico calculations, along with experimental melting points, were then incorporated into a thermodynamic equation for solubility estimations that largely matched the reference solubility values. It was revealed that the effect of melting point on the solubility is minor compared to the partition coefficient, and an average melting point (162.7 °C) could replace the experimental values, with similar results. The in-silico methods classified 20.76% (± 3.07%) as Class 1, 41.51% (± 3.32%) as Class 2, 30.49% (± 4.47%) as Class 3, and 6.27% (± 4.39%) as Class 4. In conclusion, in-silico methods can be used for BCS classification of drugs in early development, from merely their molecular formula and without foreknowledge of their chemical structure, which will allow for the improved selection, engineering, and developability of candidates. These in-silico methods could enhance success rates, reduce costs, and accelerate oral drug products development.

  10. Retributive and restorative justice.

    PubMed

    Wenzel, Michael; Okimoto, Tyler G; Feather, Norman T; Platow, Michael J

    2008-10-01

    The emergence of restorative justice as an alternative model to Western, court-based criminal justice may have important implications for the psychology of justice. It is proposed that two different notions of justice affect responses to rule-breaking: restorative and retributive justice. Retributive justice essentially refers to the repair of justice through unilateral imposition of punishment, whereas restorative justice means the repair of justice through reaffirming a shared value-consensus in a bilateral process. Among the symbolic implications of transgressions, concerns about status and power are primarily related to retributive justice and concerns about shared values are primarily related to restorative justice. At the core of these processes, however, lies the parties' construal of their identity relation, specifically whether or not respondents perceive to share an identity with the offender. The specific case of intergroup transgressions is discussed, as are implications for future research on restoring a sense of justice after rule-breaking.

  11. Promising indeed: the role of "experts" and practitioners in the introduction and use of new materials and techniques in restorative dentistry.

    PubMed

    Donovan, Terry E

    2004-01-01

    Contemporary general practitioners are facing enormous challenges. Whether they want to or not, they are forced to manage a complex small business and are often ill equipped educationally and emo- tionally to do so. They also have to manage a substantial number of staff members, often with complex emotional interactions. Young dentists today are frequently forced to service considerable debt as a result of educational costs and high practice overheads. Manufacturers and dental laboratories are aggressively marketing new products and procedures at an unprecedented rate, often with sophisticated marketing techniques. These practitioners also have lives outside of work as wives or husbands, fathers or mothers, scout leaders, and coaches. Although contemporary clinicians are faced with many challenges, they also must accept some responsibilities regarding new products and practices. They must possess critical thinking skills and a basic knowledge of materials science. Whether contemporary dental schools provide their students with an education that stimulates this is a topic for another editorial. Educationally prepared or not, practitioners should filter information through common sense and past experience. New products should be introduced to the practice carefully and used in a conservative manner. These overstressed individuals deserve the best possible information from those of us who are considered experts. We cannot continue to be politically correct when describing new products and materials. We need to call it the way it is. Those who are considered experts have achieved that status through a combination of hard work, talent, luck, and perhaps some sleight of hand. There are legitimate rewards to be reaped as an expert, but with those come responsibilities. Referring to products with no clinical testing or evidence-based foundation as "promising indeed" does not meet those responsibilities. PMID:15801337

  12. Current aspects of restoring traumatically fractured teeth.

    PubMed

    Krastl, Gabriel; Filippi, Andreas; Zitzmann, Nicola U; Walter, Clemens; Weiger, Roland

    2011-01-01

    Endodontic and restorative considerations are of primary significance in the treatment of tooth fractures. Since exposed dentinal tubules permit invasion of bacteria into the endodontic system, a protective dressing must be applied as part of the emergency treatment. Provided the dentin wound has been sealed, restorative treatment can also be carried out at a later stage. The fractured tooth fragment can be reattached using adhesive protocols in order to restore function and esthetic appearance. If reattachment is difficult or impossible, eg, in cases of multiple or missing fragments, current composite materials enable excellent esthetic results. Minimally-invasive direct composite restorations are preferred over the more invasive indirect restorations, at least in immature teeth with an extensive coronal pulp dimension. Restorative treatment of crown-root fractures is frequently demanding due to inaccessible subgingival fracture margins. Extrusion of the remaining root is an alternative method to surgical crown lengthening for re-establishing the biological width. This can be carried out either orthodontically (forced eruption), or surgically (intra-alveolar transplantation). Although the treatment of crown-root fractures is one of the most technically sensitive procedures in dental traumatology and is frequently considered as a long-term temporary restoration, tooth conservation up to the age at which implants can be placed may be regarded as a success.

  13. Smile transformations with the use of direct composite restorations.

    PubMed

    Sameni, Abdi

    2013-01-01

    Mutual concerns shared by dentists and patients regarding removal of natural tooth structure affirm the need for non-invasive restorative treatments. Direct composite restorations are among today's conservative treatment modalities. Direct bonding procedures provide patients with an alternative to high biologic risk and expensive indirect porcelain restorations. This article discusses the principles involved in smile design cases, ways to successfully combine different treatment modalities, and materials to achieve outstanding esthetic and functional results. The article also demonstrates the versatility of today's composite materials for direct smile design restorations.

  14. Bearing restoration by grinding

    NASA Technical Reports Server (NTRS)

    Hanau, H.; Parker, R. J.; Zaretsky, E. V.; Chen, S. M.; Bull, H. L.

    1976-01-01

    A joint program was undertaken by the NASA Lewis Research Center and the Army Aviation Systems Command to restore by grinding those rolling-element bearings which are currently being discarded at aircraft engine and transmission overhaul. Three bearing types were selected from the UH-1 helicopter engine (T-53) and transmission for the pilot program. No bearing failures occurred related to the restoration by grinding process. The risk and cost of a bearing restoration by grinding programs was analyzed. A microeconomic impact analysis was performed.

  15. Restorative dentistry for the pediatric patient.

    PubMed

    Hackmyer, Steven P; Donly, Kevin J

    2010-11-01

    The American Academy of Pediatric Dentistry sponsored the Pediatric Restorative Dentistry Consensus Conference in 2002. This paper will review the consensus statements that were issued as a result of the conference. Since the conference there have been advances in procedures, materials, and techniques that need to be considered in terms of some of the consensus statements. The introduction of the First Dental Home, interim therapeutic restoration and nanotechnology are examples of some of the materials and techniques that are now part of everyday pediatric dentistry. This paper will discuss the updates as it relates to each of the 2002 consensus statements.

  16. A provisional regulatory gene network for specification of endomesoderm in the sea urchin embryo

    NASA Technical Reports Server (NTRS)

    Davidson, Eric H.; Rast, Jonathan P.; Oliveri, Paola; Ransick, Andrew; Calestani, Cristina; Yuh, Chiou-Hwa; Minokawa, Takuya; Amore, Gabriele; Hinman, Veronica; Arenas-Mena, Cesar; Otim, Ochan; Brown, C. Titus; Livi, Carolina B.; Lee, Pei Yun; Revilla, Roger; Schilstra, Maria J.; Clarke, Peter J C.; Rust, Alistair G.; Pan, Zhengjun; Arnone, Maria I.; Rowen, Lee; Cameron, R. Andrew; McClay, David R.; Hood, Leroy; Bolouri, Hamid

    2002-01-01

    We present the current form of a provisional DNA sequence-based regulatory gene network that explains in outline how endomesodermal specification in the sea urchin embryo is controlled. The model of the network is in a continuous process of revision and growth as new genes are added and new experimental results become available; see http://www.its.caltech.edu/mirsky/endomeso.htm (End-mes Gene Network Update) for the latest version. The network contains over 40 genes at present, many newly uncovered in the course of this work, and most encoding DNA-binding transcriptional regulatory factors. The architecture of the network was approached initially by construction of a logic model that integrated the extensive experimental evidence now available on endomesoderm specification. The internal linkages between genes in the network have been determined functionally, by measurement of the effects of regulatory perturbations on the expression of all relevant genes in the network. Five kinds of perturbation have been applied: (1) use of morpholino antisense oligonucleotides targeted to many of the key regulatory genes in the network; (2) transformation of other regulatory factors into dominant repressors by construction of Engrailed repressor domain fusions; (3) ectopic expression of given regulatory factors, from genetic expression constructs and from injected mRNAs; (4) blockade of the beta-catenin/Tcf pathway by introduction of mRNA encoding the intracellular domain of cadherin; and (5) blockade of the Notch signaling pathway by introduction of mRNA encoding the extracellular domain of the Notch receptor. The network model predicts the cis-regulatory inputs that link each gene into the network. Therefore, its architecture is testable by cis-regulatory analysis. Strongylocentrotus purpuratus and Lytechinus variegatus genomic BAC recombinants that include a large number of the genes in the network have been sequenced and annotated. Tests of the cis-regulatory predictions of

  17. Tensile strength of restorative resins.

    PubMed

    Zidan, O; Asmussen, E; Jørgensen, K D

    1980-06-01

    The purpose of the present work was to measure the tensile strength of restorative resins and to study the effect of the method of measurement on the recorded results. A direct pull method using dumb-bell shaped specimens was used. The tensile strength of the resins was also tested using the diametral compression method suggested by the A.D.A. It was found that the method of testing affects the results. Although the diametral compression method is a simple method, it cannot be considered reliable for all types of material. The tensile strength of the conventional composites was significantly higher than the tensile strength of the microfilled composites.

  18. Ecosystem restoration: Chapter 4

    USGS Publications Warehouse

    Cullinane Thomas, Catherine M.; Skrabis, K. E.; Gascoigne, William

    2012-01-01

    The Department of the Interior extensively supports―through its mission, policy, programs, and funding― the study, planning, implementation, and monitoring of ecosystem restoration. This commitment is reflected in the Department's FY2011-2016 Strategic Plan.

  19. Restoration of Ailing Wetlands

    PubMed Central

    Schmitz, Oswald J.

    2012-01-01

    It is widely held that humankind's destructive tendencies when exploiting natural resources leads to irreparable harm to the environment. Yet, this thinking runs counter to evidence that many ecological systems damaged by severe natural environmental disturbances (e.g., hurricanes) can restore themselves via processes of natural recovery. The emerging field of restoration ecology is capitalizing on the natural restorative tendencies of ecological systems to build a science of repairing the harm inflicted by humans on natural environment. Evidence for this, for example, comes from a new meta-analysis of 124 studies that synthesizes recovery of impacted wetlands worldwide. While it may take up to two human generations to see full recovery, there is promise, given human will, to restore many damaged wetlands worldwide. PMID:22291573

  20. ESTUARINE HABITAT RESTORATION

    SciTech Connect

    Thom, Ronald M.; Borde, Amy B.

    2015-09-01

    Restoring estuarine habitats generally means repairing damages caused by humans and natural forces. Because of the extensive human occupation, development, and use of coastal areas for centuries, the extensive estuarine habitats have been either destroyed or significantly impaired.

  1. Restoration of ailing wetlands.

    PubMed

    Schmitz, Oswald J

    2012-01-01

    It is widely held that humankind's destructive tendencies when exploiting natural resources leads to irreparable harm to the environment. Yet, this thinking runs counter to evidence that many ecological systems damaged by severe natural environmental disturbances (e.g., hurricanes) can restore themselves via processes of natural recovery. The emerging field of restoration ecology is capitalizing on the natural restorative tendencies of ecological systems to build a science of repairing the harm inflicted by humans on natural environment. Evidence for this, for example, comes from a new meta-analysis of 124 studies that synthesizes recovery of impacted wetlands worldwide. While it may take up to two human generations to see full recovery, there is promise, given human will, to restore many damaged wetlands worldwide.

  2. Developing a provisional, international Minimal Dataset for Juvenile Dermatomyositis: for use in clinical practice to inform research

    PubMed Central

    2014-01-01

    Background Juvenile dermatomyositis (JDM) is a rare but severe autoimmune inflammatory myositis of childhood. International collaboration is essential in order to undertake clinical trials, understand the disease and improve long-term outcome. The aim of this study was to propose from existing collaborative initiatives a preliminary minimal dataset for JDM. This will form the basis of the future development of an international consensus-approved minimum core dataset to be used both in clinical care and inform research, allowing integration of data between centres. Methods A working group of internationally-representative JDM experts was formed to develop a provisional minimal dataset. Clinical and laboratory variables contained within current national and international collaborative databases of patients with idiopathic inflammatory myopathies were scrutinised. Judgements were informed by published literature and a more detailed analysis of the Juvenile Dermatomyositis Cohort Biomarker Study and Repository, UK and Ireland. Results A provisional minimal JDM dataset has been produced, with an associated glossary of definitions. The provisional minimal dataset will request information at time of patient diagnosis and during on-going prospective follow up. At time of patient diagnosis, information will be requested on patient demographics, diagnostic criteria and treatments given prior to diagnosis. During on-going prospective follow-up, variables will include the presence of active muscle or skin disease, major organ involvement or constitutional symptoms, investigations, treatment, physician global assessments and patient reported outcome measures. Conclusions An internationally agreed minimal dataset has the potential to significantly enhance collaboration, allow effective communication between groups, provide a minimal standard of care and enable analysis of the largest possible number of JDM patients to provide a greater understanding of this disease. This

  3. Placement protocol for an anterior fiber-reinforced composite restoration.

    PubMed

    Hornbrook, D S

    1997-01-01

    The new classification of metal-free restorative materials provides the clinician with a durable, flexible, and aesthetic laboratory-fabricated alternative to conventional porcelain-fused-to-metal (PFM) full-coverage crowns, inlay and onlay restorations, and single pontic bridges. With exceptional physical and optical characteristics, restorations fabricated utilizing the new ceramic optimized polymer (Ceromer) (Targis, Ivoclar Williams, Amherst, NY) and fiber-reinforced composite (FRC) framework (Vectris, Ivoclar Williams, Amherst, NY) materials can also be utilized predictably in the anterior segment. The success of metal-free restorations can be achieved by following conventional prosthodontic principles for preparation, cementation, and finishing. This article demonstrates the appropriate treatment protocol in order to achieve aesthetically acceptable and durable anterior results utilizing a metal-free restorative system for "Maryland-like" bridge restorations.

  4. [The assessment of the regularity of the nephron anlage tubule formation on the basis of provisionality principle].

    PubMed

    Panteleev, S M; Vikhareva, L V; Mal'tseva, N G; Ushakov, A L; Khamoshina, I Ia; Iaroslavtseva, O F; Chivshina, R V; Pal'chenkova, N O; Margarian, A V; Belkhoroeva, M M

    2011-01-01

    The study of the definitive kidneys of 94 human embryos and fetuses at 4.5 to 12 weeks of gestation, has demonstrated that the formation of the proximal nephron tubules resulted from the cellular proliferation in the area of transition of the capsule of the renal corpuscle into the tubular part of the nephron that occurs only after the completion of the segregation of the renal corpuscle and the distal tubule within the nephron anlage. The formation of the renal tubules in the nephron anlage seems to be determined phylogenetically, while the initial differentiation of the distal tubule is a provisional feature.

  5. [Restoring esthetics and function of posterior teeth using direct composite restoration].

    PubMed

    Samet, N

    2001-10-01

    The growing demand for esthetic restorations in the posterior segments and the reports from all over the world concerning the possibility of a toxic effect of amalgam brought to the development of the composite resin materials. These allow excellent esthetic results without compromising the quality and long-term stability of the restorations. Out of the various types of posterior esthetic restorations, the most available are the direct ones. There are several substantial differences between fabricating amalgam or posterior composite restorations. The most significant difference concerns bonding to the tooth structures. The key to success in these restorations is the understanding of the reasons for failure, and the ways to prevent them. The failures are divided into two groups: biological failures--namely secondary caries, and mechanical failures--namely fracture and abrasion. The other key is understanding the materials used and their proper handling. This article illustrates in detail a step-by-step procedure the sequence of fabricating a posterior composite restoration in a posterior mandibular tooth, describing both techniques and materials used.

  6. Posterior composite restoration update: focus on factors influencing form and function.

    PubMed

    Bohaty, Brenda S; Ye, Qiang; Misra, Anil; Sene, Fabio; Spencer, Paulette

    2013-01-01

    Restoring posterior teeth with resin-based composite materials continues to gain popularity among clinicians, and the demand for such aesthetic restorations is increasing. Indeed, the most common aesthetic alternative to dental amalgam is resin composite. Moderate to large posterior composite restorations, however, have higher failure rates, more recurrent caries, and increased frequency of replacement. Investigators across the globe are researching new materials and techniques that will improve the clinical performance, handling characteristics, and mechanical and physical properties of composite resin restorative materials. Despite such attention, large to moderate posterior composite restorations continue to have a clinical lifetime that is approximately one-half that of the dental amalgam. While there are numerous recommendations regarding preparation design, restoration placement, and polymerization technique, current research indicates that restoration longevity depends on several variables that may be difficult for the dentist to control. These variables include the patient's caries risk, tooth position, patient habits, number of restored surfaces, the quality of the tooth-restoration bond, and the ability of the restorative material to produce a sealed tooth-restoration interface. Although clinicians tend to focus on tooth form when evaluating the success and failure of posterior composite restorations, the emphasis must remain on advancing our understanding of the clinical variables that impact the formation of a durable seal at the restoration-tooth interface. This paper presents an update of existing technology and underscores the mechanisms that negatively impact the durability of posterior composite restorations in permanent teeth.

  7. [Combined crown lengthening surgery with restorative therapy for inducing papilla growth: a case report].

    PubMed

    Le, Di; Hu, Wen-jie; Zhang, Hao

    2013-04-18

    A young lady with unsatisfied restorations of upper anterior teeth and swollen gum wanted to improve aesthetics. Oral examination showed that 12-22 were provisional crowns with normal occlusion, poorly gingival contour and gummy smile. The gingiva was red, light swollen and bleeding on probing. X-ray showed the roots of 11, 21 were short and the alveolar bone absorbed. After the periodontal initial treatment, an ideal location of gingival margin was determined. Then, an esthetic periodontal surgery was performed to recover the biology width and the gingival margin was fitted with the anterior teeth. The temporary restorations were made twice to guide the gingiva growth by changing the shape of the restorations and moving up the contact points of the restorations. The ceramic crowns were completed 3 months after the operation. The gummy smile disappeared and the gingival margin was filled well with the upper anterior ceramic crowns. The 14-month follow-up presented a satisfied effect. Crown lengthening surgery combined restorative therapy could lead papilla to grow well. This process is beneficial for the future treatment plan and clinical esthetic evaluation.

  8. Immediate loading of four implants (BTLock®) in the maxilla and provisional restoration with guide-surgery (SimPlant, Materialise®): case report

    PubMed Central

    SPINELLI, D.; DE VICO, G.; SCHIAVETTI, R.; BONINO, M.; POZZI, A.; BOLLERO, P.; BARLATTANI, A.

    2010-01-01

    SUMMARY The severe atrophy of the jaws are a challenging therapeutic problem, since the increase in bone is necessary to allow the placement of a sufficient number of implants. Combining immediate functionalization with the concept of guided surgery they combine the advantages offered by the innovative surgical and prosthetic implant technique (All-on-Four®) with those of computer-assisted planning in cases of severe bone atrophy. The method used in this case report, combines these two concepts in a surgical and prosthetic protocol safe and effective for the immediate function of 4 implants to support a fixed prosthesis in completely edentulous subjects. The integration of technology with immediate function with the concept of computer-guided surgery for implant placement and rehabilitation of completely edentulous jaws is now a predictable treatment modality with implant survival comparable to the traditional protocols. PMID:23285381

  9. Conservation, Preservation and Restoration in Nigerian Libraries.

    ERIC Educational Resources Information Center

    Ojo-Igbinoba, M. E.

    1991-01-01

    Addresses problems involved with the conservation, preservation, and restoration of library materials in Nigeria. Topics discussed include insect pests; light, heat, and humidity; atmospheric pollution and dust; natural disasters including fire and floods; theft and vandalism; acidity of paper; binding and mending; and trained personnel. (15…

  10. Restoring the prairie

    SciTech Connect

    Mlot, C.

    1990-12-01

    The US DOE at the Fermi National Accelerator Laboratory in Batavia, Illinois, prairie restoration is taking place in order to conserve the rich topsoil. This is the largest of many prairie restoration experiments. Big bluestem grass (Andropogon gerardi), blue grama (Bouteloua gracilis), and buffalo grass (Buchloe dactyloides) are the main initial grasses grown. After their growth reaches enough biomass to sustain a fire, other prairie plants such as purple prairie clover and dropseed grass appear. The goal of this is to provide a generous refuge for disappearing native plants and animals, a site for scientific research, and a storehouse of genes adapted to a region that produces much of the worlds food. Plans for restoring the marsh and oak savanna, also native to the Fermilab site are also in the works.

  11. Restoration of Shoulder Function.

    PubMed

    Boe, Chelsea C; Elhassan, Bassem T

    2016-08-01

    Restoration of shoulder function in patients with brachial plexus injury can be challenging. Initial reported efforts were focused on stabilizing the shoulder, improving inferior subluxation and restoring abduction and flexion of the joint. Recent advancements and improved understanding of coordinated shoulder motion and the biomechanical properties of the muscles around the shoulder applicable to tendon transfer have expanded available surgical options to improve shoulder function, specifically external rotation. Despite the advances in reconstructive options, brachial plexus injury remains a serious problem that requires complex surgical solutions, prolonged recovery, and acceptance of functional loss. PMID:27387074

  12. 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.

  13. 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

  14. Vascular restoration therapy and bioresorbable vascular scaffold

    PubMed Central

    Wang, Yunbing; Zhang, Xingdong

    2014-01-01

    This article describes the evolution of minimally invasive intervention technologies for vascular restoration therapy from early-stage balloon angioplasty in 1970s, metallic bare metal stent and metallic drug-eluting stent technologies in 1990s and 2000s, to bioresorbable vascular scaffold (BVS) technology in large-scale development in recent years. The history, the current stage, the challenges and the future of BVS development are discussed in detail as the best available approach for vascular restoration therapy. The criteria of materials selection, design and processing principles of BVS, and the corresponding clinical trial results are also summarized in this article. PMID:26816624

  15. Esthetic restorations designed with confidence and predictability.

    PubMed

    Gaglio, M A

    2001-06-01

    When the ProCAD product line is used in combination with the CEREC system, clinicians have at their disposal an armamentarium of materials with which to achieve greater predictability, precision, and control in fabricating chairside all-ceramic restorations. At a time when time is the dentist's and patient's most precious commodity, the ProCAD line enables clinicians to definitively restore form, function, and esthetics in a single visit, regardless of the specific individual indirect treatment indication (Figures 13A through 13C, and 14A through 14C).

  16. Restoring Fossil Creek

    ERIC Educational Resources Information Center

    Flaccus, Kathleen; Vlieg, Julie; Marks, Jane C.; LeRoy, Carri J.

    2004-01-01

    Fossil Creek had been dammed for the past 90 years, and plans were underway to restore the stream. The creek runs through Central Arizona and flows from the high plateaus to the desert, cutting through the same formations that form the Grand Canyon. This article discusses the Fossil Creek monitoring project. In this project, students and teachers…

  17. Model for Coastal Restoration

    SciTech Connect

    Thom, Ronald M.; Judd, Chaeli

    2007-07-27

    Successful restoration of wetland habitats depends on both our understanding of our system and our ability to characterize it. By developing a conceptual model, looking at different spatial scales and integrating diverse data streams: GIS datasets and NASA products, we were able to develop a dynamic model for site prioritization based on both qualitative and quantitative relationships found in the coastal environment.

  18. Conservative indirect restorations for posterior teeth. Cast versus bonded ceramic.

    PubMed

    Donovan, T E; Chee, W W

    1993-07-01

    The practitioner today has a number of alternative restorative modalities from which to chose when faced with the necessity of restoring posterior teeth. The primary options with extensively broken down posterior teeth are cast gold and bonded ceramic inlays, onlays, and partial veneer restorations. The dentist and informed patient should make the choice of which modality is appropriate based on a number of criteria. Certainly, based on the criteria of basic physical properties, potential for marginal integrity and stability of that integrity, cast gold is the material of choice. In terms of conservation of tooth structure and systemic biocompatibility, both restoration types are excellent. With regard to effects on long-term pulpal health, much remains unknown with many of the materials used with bonded restorations at the present time. Conservative cast gold restorations have proved to be very successful in this regard over the long term. The potential for tooth strengthening with bonded restorations is certainly an exciting, but as yet, unproven, clinical reality. Thus, until those clinical data are available, the most predictable means of restoration of extensively broken down posterior teeth is with partial-coverage cast gold, protecting cusps at risk as required (Fig. 9). As mentioned previously, cast gold inlays are also a very conservative and predictable restoration (Fig. 10). Both cast gold and bonded ceramic restorations are technically demanding, but the details required to produce excellent gold castings are well defined, and can be learned readily. Much remains to be learned regarding the materials and the techniques used to fabricate bonded ceramic restorations. Priority issues would seem to be reaching a consensus regarding the details of tooth preparation and the development of improved luting resins with improved wear resistance. Simplified techniques to improve the quality of the fit of these types of restoration also are of paramount importance

  19. 14. EAST ELEVATION, COTTAGE. EXTERIOR NEARLY RESTORED. INTERIOR UNDERGOING RESTORATION. ...

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

    14. EAST ELEVATION, COTTAGE. EXTERIOR NEARLY RESTORED. INTERIOR UNDERGOING RESTORATION. EUCALYPTUS TREE PLANTED BY GERTRUDE KEIL PLANNED FOR REMOVAL. - Gold Ridge Farm, 7777 Bodega Avenue, Sebastopol, Sonoma County, CA

  20. [Influence of implant restoration on traditional restoration idea].

    PubMed

    Liu, H C

    2016-01-01

    Implant restoration affected the traditional restoration idea. Artificial implant restoration has a profound influence on the design of dental restoration. Implant supported prostheses have not only changed the method of oral rehabilitation, but also integrated revolutionary concept with the traditional treatment protocol. By using implants, posterior missing molars can be effectively restored and thus eliminating the disadvantages of traditional removable partial denture for Kennedy classification Ⅰ, Ⅱ partically edentulous dentition. Full edentulous arch can also be restored with implant fixed denture which provide much better oral health related quality of life compared with the traditional complete denture. It is useful to master the theory and skills of artificial implant restoration, and to provide a reference for the restoration of oral physiological function.