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Sample records for provisional restoration materials

  1. Chairside resin-based provisional restorative materials for fixed prosthodontics.

    PubMed

    Strassler, Howard E; Lowe, Robert A

    2011-01-01

    Provisional restorations are vital to fixed prosthodontics treatment, providing an important diagnostic function while in place. In addition to protecting the prepared teeth, provisionalization enables clinicians to refine biologic and biomechanical issues before the final restoration is fabricated. Adjustments can be made in the provisional restoration to achieve both the clinician's and patient's desired results. The fabrication of temporary restorations requires that clinicians be proficient with a variety of materials and techniques that can be used to make well-adapted and functional provisionals. There are many material choices available to temporize a single crown as well as multi-unit fixed partial dentures, and the selection of provisional materials should be made based on a case-by-case evaluation. This article provides a review of polymeric resin provisional materials. PMID:22167927

  2. Provisional materials: key components of interim fixed restorations.

    PubMed

    Perry, Ronald D; Magnuson, Britta

    2012-01-01

    Clinicians have many choices of provisional materials from which to choose when fabricating interim fixed restorations. While traditional materials are still in use today, temporary materials are continuously being updated and improved upon. In addition to the functional necessities required of the provisional material, it must also provide esthetic value for the patient. This article provides an overview of provisional materials, including newer bis-acryls that have helped eliminate some of the challenges associated with traditional acrylic materials. Composite resin preformed crowns for single-unit provisional applications are also discussed, along with CAD/CAM-fabricated materials. Regardless of the material selected, a provisional restoration must maintain and protect the underlying tooth structure from ill effects. PMID:22432178

  3. Provisionalization: the key to cosmetic & restorative success.

    PubMed

    Rossein, K

    1995-07-01

    This article demonstrates the importance of provisionals in achieving success with the final restoration. The purposes of a provisional restoration are discussed as well as the various types of provisional materials that are available. A direct technique, using a clear plastic matrix for the fabrication of a provisional bridge, is described. Included is a procedure for forming a pontic that will have accurate contacts and proper contours and embrasures every time. PMID:8595589

  4. In vitro color stability of provisional crown and bridge restoration materials.

    PubMed

    Ergün, Gülfem; Mutlu-Sagesen, Lâmia; Ozkan, Yalçin; Demirel, Erol

    2005-09-01

    Discoloration of provisional restorations can be an esthetic problem, especially when the treatment plan requires long-term provisionalization. In this study, therefore, we examined the effects of staining solution on the color stability of these provisional crown and bridge restoration materials: Structur, Temdent, and Tab 2000. Treatment solutions were namely carrot juice, tea, cola, light cola, and distilled water. Thirty samples were prepared for each type of provisional material, such that a total of 90 samples were prepared. The color value of each sample was measured with a colorimeter at baseline and after one day, one week, two weeks, and four weeks of immersion in various treatment solutions. Results were determined using the CIELAB system. Color change data were calculated and subjected to two-way analysis of variance. To examine significant interactions, one-way ANOVA and Tukey's multiple comparisons test were performed to identify differences between the solutions (p < or = 0.05). After four weeks of treatment, color difference values were found to range from 0.20 to 3.99 deltaE* units. The highest color difference values were obtained in carrot juice, cola, and tea with Structur samples after four weeks, where these values were categorized as "noticeable" and "unacceptable" color change values. Based on the results of this study, we do not recommend amine-containing Structur to be used as a provisional crown and bridge restorative material for treatments of a longer duration. PMID:16279724

  5. Effects of Current Provisional Restoration Materials on the Viability of Fibroblasts

    PubMed Central

    Ulker, Mustafa; Ulker, H. Esra; Zortuk, Mustafa; Bulbul, Mehmet; Tuncdemir, Ali Riza; Bilgin, M. Selim

    2009-01-01

    Objectives: The aim of the present study was to evaluate the cytotoxic effects of three different provisional restoration materials on fibroblasts. Two bis-acrylic based [Tempofit Duomix (Detax), Protemp 3 Garant (3M ESPE)] and one urethan dimethacrylate [Revotek LC (GC Corporation)] based provisional restoration materials used. Methods: Materials were prepared according to the manufacturers’ instructions in standard teflon disks (2×5 mm) and four samples were extracted in 7 ml of Basal Medium Eagle with 10% new born calf serum and 100 mg/ml penicillin/streptomycin for 24 hours. The L929 fibroblast cells were plated (25.000 cells/ml) in well plates, and maintained in a CO2 incubator at 37°C for 24h. After 24 hours, the incubation medium was replaced by the immersed medium in which the samples were stored and the L929 fibroblasts were incubated in contact with eluates for 24 hours at 37°C for 24h. The fibroblast cell viability was analyzed by measuring the mitochondrial activity with the methyltetrazolium test (MTT). Twelve well used for each specimen and experiment repeated for two times. The data was statistically analyzed by Mann-Whitney U tests. Results: The results showed that, Revotek LC and Protemp 3 Garant were not cytotoxic for fibroblast cells when compared to control group (P>.05). However, Tempofit duomix was cytotoxic for L929 fibroblasts when compared to control group and other tested materials (P<.05). Conclusions: Taking into consideration the limitations of an in vitro study, our study indicate that provisional restoration materials might have cytotoxic effects on fibroblasts and should be selected carefully for clinical applications. PMID:19421391

  6. Shear bond strength of provisional restoration materials repaired with light-cured resins.

    PubMed

    Chen, Hsiu-Lin; Lai, Yu-lin; Chou, I-chiang; Hu, Chiung-Jen; Lee, Shyh-yuan

    2008-01-01

    This study evaluated the repair bond strengths of light-cured resins to provisional restoration materials with different chemical compositions and polymerization techniques. Fifty discs (10 mm in diameter and 1.5 mm thick) were fabricated for each provisional resin base material, including a self-cured methacrylate (Alike), self-cured bis-acrylate (Protemp 3 Garant), light-cured bis-acrylate (Revotek LC) and a heat-cured methacrylate (Namilon). All specimens were stored in distilled water at 37 degrees C for seven days before undergoing repair with one of four light-cured resins, including AddOn, Revotek LC, Dyractflow and Unifast LC and a self-cured resin (Alike), according to the manufacturers' instructions, for a total of 200 specimens. After 24 hours of storage in 37 degrees C water, the shear bond strengths were measured with a universal testing machine and fracture surfaces were examined under a stereomicroscope. Two-way ANOVA revealed that provisional resin-base material (p < 0.001), repair material (p < 0.001) and their interactions (p < 0.001) significantly affected the repair strength. Tukey's multiple comparisons showed that the lowest bonding strengths were found in specimens of heat-cured methacrylate resin materials repaired with bis-acryl resins, with their failure modes primarily being of the adhesive type. The highest bond strengths were recorded when the provisional resin-base materials and repairing resins had similar chemical components and the failure modes tended to be of the cohesive type. PMID:18833857

  7. Evaluation of resins for provisional restorations.

    PubMed

    Burgess, J O; Haveman, C W; Butzin, C

    1992-06-01

    An in vivo study of two resin materials (Barricaid and Caulk Temporary Crown and Bridge Resin) was done to determine the retention, post-operative sensitivity, and fabrication time of provisional restorations made from these materials. Following the placement of these resins in 67 intracoronal cavity preparations of 19 adult patients, a baseline evaluation was made which included a clinical examination and color slides. Twenty-four hours after the temporary restorations were placed, the patients completed evaluations of the post-operative sensitivity experienced. There was no difference in post-operative sensitivity between the teeth restored with Barricaid or Caulk Temporary Crown and Bridge Resin. At the insertion appointment of the final restoration, the interim restoration's success rate was determined. There was no difference between the retention of the two provisional materials. Fabrication time was significantly different with Barricaid restorations requiring less than one-half the fabrication time of the Caulk Temporary Crown and Bridge Resin material. PMID:1388950

  8. 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

  9. The effect of placement of glass fibers and aramid fibers on the fracture resistance of provisional restorative materials.

    PubMed

    Saygili, Gülbin; Sahmali, Sevil M; Demirel, Figen

    2003-01-01

    The fracture resistance of provisional restorations is an important concern for the restorative dentist. The fracture resistance of a material is directly related to its transverse strength. Six specimens of similar dimensions were prepared from three resins (PMMA, PEMA and BIS acryl-composite). The resins were reinforced with glass and aramid fibers. The samples were tested immediately after the material set, following seven days of wet storage using three-point compression loading. The results were analyzed with an analysis of variance (ANOVA). Fracture resistance of the specimens was statistically different (p < 0.001) among the materials. Specimens reinforced with glass fibers showed higher transverse strength (149.82 MPa). The fiber reinforcement of resin materials increased the strength values (20-50%). Within the limitations of this study, the transverse strengths of PMMA, PEMA and BIS acryl-resin composites were improved after reinforcement with glass and aramid fibers. PMID:12540123

  10. Effect of Dietary Simulating Solvents on the Mechanical Properties of Provisional Restorative Materials-An In Vitro Study.

    PubMed

    Muley, Bipin Y; Shaikh, Sameera R; Tagore, Mohana M; Khalikar, Arun N

    2014-12-01

    The purpose of this investigation was to evaluate the mechanical properties of provisional restorative materials after storage in dietary simulating solvents. A total of 120 specimens, 40 specimens each of Luxatemp Star, Revotek LC and DPI Self Cure were prepared. The specimens were divided into four groups with 10 specimens each and stored in dietary simulating solvents for 7 days at 37 °C as follows: Group I-Control, Group II-Artificial saliva, Group III-0.02 N Citric acid and Group IV-Heptane. After 7 days, flexural strength was obtained using universal testing machine at a crosshead speed of 5 mm/min and the fractured specimens were immediately subjected to the microhardness test knoop hardness number by using Knoop microhardness tester (10 gm/15 s). The data were analyzed for difference by use of Kruskal-Wallis and Dunn's multiple comparison tests using a significance level of 0.05 to determine the mean differences. Significant effect was observed on the properties of provisional restorative materials after storage in dietary simulating solvents as compared to the control group (p ≤ 0.05). Bis-acryl resin based Luxatemp Star showed significantly superior flexural strength and hardness as compared to the Revotek LC and DPI Self Cure in dietary simulating solvents. Within the limitations of this study, it may be concluded that dietary simulating solvents showed significant influence on the mechanical properties of the provisional restorative materials. PMID:26199498

  11. Discoloration of Provisional Restorations after Oral Rinses

    PubMed Central

    Turgut, Sedanur; Bagis, Bora; Ayaz, Elif Aydogan; Ulusoy, Kıvanç Utku; Altintas, Subutay Han; Korkmaz, Fatih Mehmet; Bagis, Nilsun

    2013-01-01

    Purpose: Oral rinses are widely used to promote periodontal health with provisional restorations during the interim period. The aim of this study was to compare the discoloration of provisional restoration materials with different oral rinses. Material and Methods: A total of 140 disc-shaped specimens (shade A2) (10 mm x 2 mm) were prepared from one PMMA-based (TemDent Classic®) and three different bis-acrylic-based (Protemp II®, Luxatemp® and Fill-In®) provisional restoration materials (n=7). The color values (L*, a*, and b*) of each specimen were measured before and after exposure with a colorimeter, and the color changes (∆E) were calculated according to the CIE L*a*b* system. The specimens were immersed in each of the 4 oral rinses (alcohol-containing mouthwash, chlorhexidine, benzydamine HCl, benzydamine HCl and chlorhexidine) twice a day for 2 minutes. After 2 minutes of immersion in the oral rinses, the specimens were immersed in artificial saliva. The specimens were exposed to the oral rinses and the artificial saliva for 3 weeks. Two-way ANOVA, the Bonferroni test and the paired sample t-test were used for statistical analyses (p<0.05). Results: Comparison of the discoloration from the oral rinses after immersion for three weeks revealed no significant differences (p>0.05). The lowest color change was observed in PMMA-based Temdent in all oral rinses (p<0.05). There were no significant differences between the bis-acryl composites after immersion in saliva or the mixture of benzydamine HCl and chlorhexidine and the alcohol-containing mouthwash for 3 weeks (p>0.05). After immersion in chlorhexidine, the color change values of Protemp II and Fill-in showed significant differences (p=0.018). Protemp II also showed less discoloration than the other bis-acryl composites, and this color change was statistically significant (p <0.05). For all oral rinses, the L* value decreased while b* values increased, and this color change was found to be statistically

  12. Evaluation of colour stability of provisional restorative materials exposed to different mouth rinses at varying time intervals: an in vitro study.

    PubMed

    Prasad, D Krishna; Alva, Harshitha; Shetty, Manoj

    2014-03-01

    The most important factor affecting esthetics is colour. Whether a definitive prosthesis or a provisional restoration, maintenance of esthetics is of prime concern along with restoration of function. Colour stability of provisional prosthesis is affected by various factors and various studies are documented in the literature on this. The purpose of this study was to evaluate the colour stability of provisional restorative materials exposed to different mouth rinses at varying time intervals. 120 discs, each of self cure tooth moulding material, Protemp 4 and Revotek LC were prepared and immersed in two mouth rinses, hexidine and periogard and evaluated for their colour stability after 1 week, 1 and 3 months. The data obtained was statistically analysed using ANOVA and Tukey's post hoc analysis. The results indicate that there is a significant difference in the colour variation of various materials in two different mouth rinses at different time intervals. Revotek LC was found to be the most colour stable material and periogard had the least staining potential at varying time intervals. PMID:24605003

  13. 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

  14. Surface integrity of provisional resin materials

    NASA Astrophysics Data System (ADS)

    Abouelatta, O. B.; El-Bediwi, A.; Sakrana, A.; Jiang, X. Q.; Blunt, L.

    2006-03-01

    Provisional resin materials are widely used in prosthetic dentistry and play an important role in the success of restorative treatment. Therefore, these materials must meet the requirements of preserving surface integrity during the treatment process. This study was done to evaluate surface roughness and microhardness of two provisional resin materials after 37 °C water storage. Two rectangular samples 21 mm × 11 mm × 3 mm, one bis-acrylic (bis-acrylic-Protemp II) and one polyethyl methacrylate (Trim®-PEMA) were fabricated as examples of provisional materials (n = 5 per material). The specimens were stored in 37 °C deionized distilled water for 24 h, 1, 2 and 3 weeks. The control specimens were not stored in water. The surface roughness of the tested materials (n = 10) was measured using a profilometer. Microhardness tests were conducted using a Vickers microscope mounted indenter system (n = 10). At 24 h, the surface roughness was recorded with bis-acrylic-Protemp II as higher than methacrylate materials. No significant differences of microhardness between Trim®-PEMA and bis-acrylic-Protemp II were recognized at 1, 2 and 3 weeks. The microhardness values increased with the increase of surface roughness and vice versa in both Trim®-PEMA and bis-acrylic-Protemp II. Both surface roughness and microhardness are affected by water storage. Bis-acrylic-Protemp II revealed better results in hardness than methacrylate resins, whereas Trim®-PEMA has a better surface roughness.

  15. Bacterial Adhesion of Porphyromonas Gingivalis on Provisional Fixed Prosthetic Materials

    PubMed Central

    Zortuk, Mustafa; Kesim, Servet; Kaya, Esma; Özbilge, Hatice; Kiliç, Kerem; Çölgeçen, Özlem

    2010-01-01

    Background: When provisional restorations are worn for long term period, the adhesion of bacteria becomes a primary factor in the development of periodontal diseases. The aims of this study were to evaluate the surface roughness and bacterial adhesion of four different provisional fixed prosthodon-tic materials. Methods: Ten cylindrical specimens were prepared from bis-acrylic composites (PreVISION CB and Protemp 3 Garant), a light-polymerized composite (Revotek LC), and a polymethyl methacrylate-based (Dentalon) provisional fixed prosthodontic materials. Surface roughness was assessed by profilometry. The bacterial adhesion test was applied using Porphyromonas gingivalis (P. gingivalis) and spectro-fluorometric method. Statistical analysis was performed using ANOVA and Dunnett t-tests. Results: All tested materials were significantly rougher than glass (P < 0.05). Revotek LC had the greatest fluorescence intensity, PreVISION and Protemp 3 Garant had moderate values and all of them had significantly more bacterial adhesion compared to glass (P < 0.05). Dentalon had the lowest fluorescence intensity among the provisional fixed prosthodontic materials. Conclusion: The quantity of bacterial adhesion and surface roughness differed among the assessed provisional fixed prosthodontic materials. The light-polymerized provisional material Revotek LC had rougher surface and more bacterial adhesion compared with the others. PMID:21448445

  16. 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). PMID:8179789

  17. Making multiple predictable single-unit provisional restorations using an indirect technique.

    PubMed

    Hansen, Paul A; Sigler, Ernie; Husemann, R Henry

    2009-10-01

    This article describes a method to fabricate single provisional restorations for multiple preparations using an indirect technique. Provisional restorations need to mimic the definitive restoration as closely as clinically possible. When multiple adjacent provisional restorations are fabricated, the ability to make each separately, with its own path of insertion and contour, aids in providing a predictable final result for the patient. Individual provisional restorations will also allow the patient to maintain better hygiene. PMID:19782829

  18. 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

  19. 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. PMID:14757958

  20. Evaluation of the Luting Cement Space for Provisional Restoration by using Various Coats of Die Spacer Materials-An Invitro Study

    PubMed Central

    Siddineni, Krishna Chaitanya; Jyothula, Ravi Rakesh Dev; Gade, Phani Krishna; Bhupathi, Deepthi; Kondaka, Sudheer; Hussain, Zakir; Paluri, Geetha Bhavani

    2014-01-01

    Aim: The present study was to evaluate the space provided for the temporary luting cement, after the application of various coats of die spacers, during the fabrication of provisional crowns and bridges. Materials and Methods: A total of 50 specimens of dental stone with provisional crowns on all these samples were prepared and were divided into five groups based on the application of various coats of different die spacers. Later these specimens were sectioned buccolingually and were observed using a stereomicroscope under 100X magnification. The images thus obtained were evaluated and noted for the amount of space between the inner surface of the provisional crown and the specimens at five different locations using Image Pro 6.0 Express software and the values were subjected to one-way ANOVA test, and unpaired t-test. Results: There was a significant increase of luting space thickness with various die spacer applications than the specimens of control group. Conclusion: Specimens of double coat applications of silver and gold die spacers showed higher luting cement space than the separating media application specimens. PMID:25386515

  1. Technique for making full-coverage provisional restorations on teeth with insufficient clinical crowns.

    PubMed

    Feinberg, Edward

    2010-11-01

    Provisional restorations fabricated with copper bands are tremendous practice builders, eliminating the sensitivity, recurrent decay and poor retention that are common with conventional temporary restorations. The copper-band provisional restoration is the ideal choice when conventional butt-joint temporary restorations are unsuitable. The technique for making this restoration is demonstrated in this article with a step-by-step "how-to" description. An analysis of the basic principles and theories behind the success of the copper band provisional restoration is also presented, as well as a discussion of the restoration's advantages and disadvantages. PMID:21226402

  2. 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

  3. Mechanical Properties and Simulated Wear of Provisional Resin Materials.

    PubMed

    Takamizawa, T; Barkmeier, W W; Tsujimoto, A; Scheidel, D; Erickson, R L; Latta, M A; Miyazaki, M

    2015-01-01

    The purpose of this study was to determine flexural properties and erosive wear behavior of provisional resin materials. Three bis-acryl base provisional resins-1) Protemp Plus (PP), 2) Integrity (IG), 3) Luxatemp Automix Plus (LX)-and a conventional poly(methylmethacrylate) (PMMA) resin, UniFast III (UF), were evaluated. A resin composite, Z100 Restorative (Z1), was included as a benchmark material. Six specimens for each of the four materials were used to determine flexural strength and elastic modulus according to ISO Standard 4049. Twelve specimens for each material were used to examine wear using a generalized wear simulation model. The test materials were each subjected to wear challenges of 25,000, 50,000, 100,000, and 200,000 cycles in a Leinfelder-Suzuki (Alabama) wear simulator. The materials were placed in custom cylinder-shaped stainless-steel fixtures, and wear was generated using a cylindrical-shaped flat-ended stainless-steel antagonist in a slurry of nonplasticized PMMA beads. Wear (mean facet depth [μm] and volume loss [mm(3)]) was determined using a noncontact profilometer (Proscan 2100) with Proscan and AnSur 3D software. The laboratory data were evaluated using two-way analysis of variance (ANOVA; factors: 1) material and 2) cycles) followed by Tukey HSD post hoc test (α=0.05). The flexural strength ranged from 68.2 to 150.6 MPa, and the elastic modulus ranged from 2.0 to 15.9 GPa. All of the bis-acryl provisional resins (PP, IG, and LX) demonstrated significantly higher values than the PMMA resin (UF) in flexural strength and elastic modulus (p<0.05). However, there was no significant difference (p>0.05) in flexural properties among three bis-acryl base provisional resins (PP, IG, and LX). Z1 demonstrated significantly (p<0.05) higher flexural strength and elastic modulus than the other materials tested. The results for mean facet wear depth (μm) and standard deviations (SD) for 200,000 cycles were as follows: PP, 22.4 (5.0); IG, 51.0 (6

  4. Long-Term Provisional Bonded Composite Restorations Make Full-Mouth Rehabilitation Possible.

    PubMed

    Wilkins, Ronald G

    2016-05-01

    Full-mouth rehabilitation cases frequently require an extended period to complete. In this case involving a patient who presented with a significant amount of lost tooth structure, treatment featured laboratory-fabricated composite provisional restorations aimed at stabilizing the dentition and enabling definitive treatment to be completed in segments. The approach taken allowed occlusal and esthetic issues to be resolved through use of the provisionals while minimizing tooth preparation. The technique provided immediate improvement in esthetics, function, and comfort. PMID:27213778

  5. Enhanced aesthetics using provisionalization.

    PubMed

    Braun, J M

    1996-01-01

    The proper fabrication of provisional restorations is integral to the overall success of restorative dentistry, as these templates are the initial architecture for the completed case. In a clinical setting, restorations may be utilized for an extended period, during which time the clinician and patient must feel confident. Due partially to a new generation of dental materials with unique properties, provisionalization can be predictably achieved. This article reviews the clinical criteria for the fabrication of interim restorations using a light cure/dual phase temporary crown and bridge material (Provipont DC, Ivoclar Vivadent, Amherst, NY) and its effect on the overall success of restorative procedures, including anterior and posterior restorations. PMID:9227154

  6. 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

  7. 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. PMID:7965911

  8. 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

  9. 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. PMID:24431771

  10. The effect of different fiber reinforcements on flexural strength of provisional restorative resins: an in-vitro study

    PubMed Central

    Parkhedkar, Rambhau D.; Mowade, Tushar Krishnarao

    2012-01-01

    PURPOSE The aim of this study was to compare the flexural strength of polymethyl methacrylate (PMMA) and bis-acryl composite resin reinforced with polyethylene and glass fibers. MATERIALS AND METHODS Three groups of rectangular test specimens (n = 15) of each of the two resin/fiber reinforcement were prepared for flexural strength test and unreinforced group served as the control. Specimens were loaded in a universal testing machine until fracture. The mean flexural strengths (MPa) was compared by one way ANOVA test, followed by Scheffe analysis, using a significance level of 0.05. Flexural strength between fiber-reinforced resin groups were compared by independent samples t-test. RESULTS For control groups, the flexural strength for PMMA (215.53 MPa) was significantly lower than for bis-acryl composite resin (240.09 MPa). Glass fiber reinforcement produced significantly higher flexural strength for both PMMA (267.01 MPa) and bis-acryl composite resin (305.65 MPa), but the polyethylene fibers showed no significant difference (PMMA resin-218.55 MPa and bis-acryl composite resin-241.66 MPa). Among the reinforced groups, silane impregnated glass fibers showed highest flexural strength for bis-acryl composite resin (305.65 MPa). CONCLUSION Of two fiber reinforcement methods evaluated, glass fiber reinforcement for the PMMA resin and bis-acryl composite resin materials produced highest flexural strength. Clinical implications On the basis of this in-vitro study, the use of glass and polyethylene fibers may be an effective way to reinforce provisional restorative resins. When esthetics and space are of concern, glass fiber seems to be the most appropriate method for reinforcing provisional restorative resins. PMID:22439093

  11. Fatigue of restorative materials.

    PubMed

    Baran, G; Boberick, K; McCool, J

    2001-01-01

    Failure due to fatigue manifests itself in dental prostheses and restorations as wear, fractured margins, delaminated coatings, and bulk fracture. Mechanisms responsible for fatigue-induced failure depend on material ductility: Brittle materials are susceptible to catastrophic failure, while ductile materials utilize their plasticity to reduce stress concentrations at the crack tip. Because of the expense associated with the replacement of failed restorations, there is a strong desire on the part of basic scientists and clinicians to evaluate the resistance of materials to fatigue in laboratory tests. Test variables include fatigue-loading mode and test environment, such as soaking in water. The outcome variable is typically fracture strength, and these data typically fit the Weibull distribution. Analysis of fatigue data permits predictive inferences to be made concerning the survival of structures fabricated from restorative materials under specified loading conditions. Although many dental-restorative materials are routinely evaluated, only limited use has been made of fatigue data collected in vitro: Wear of materials and the survival of porcelain restorations has been modeled by both fracture mechanics and probabilistic approaches. A need still exists for a clinical failure database and for the development of valid test methods for the evaluation of composite materials. PMID:11603506

  12. 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

  13. Application of the 2-piece orthodontic C-implant for provisional restoration with laser welded customized coping: a case report.

    PubMed

    Paek, Janghyun; Ahn, Hyo-Won; Jeong, Do-Min; Shim, Jeong-Seok; Kim, Seong-Hun; Chung, Kyu-Rhim

    2015-01-01

    This article presents the application of laser welding technique to fabricate an orthodontic mini-implant provisional restoration in missing area after limited orthodontic treatment. A 15-year-old boy case is presented. Two-piece orthodontic C-implant was placed after regaining space for missing right mandibular central incisor. Due to angular deviation of implant, customized abutment was required. Ready-made head part was milled and lingual part of customized abutment was made with non-precious metal. Two parts then were laser welded (Master 1000, Elettrolaser Italy, Verona, Italy) and indirect lab composite (3 M ESPE Sinfony, St. Paul, MN, USA) was built up. The patient had successful result, confirmed by clinical and radiographic examinations. Before the patient is ready to get a permanent restoration later on, this provisional restoration will be used. This case shows that a two-piece orthodontic C-implant system can be used to maintain small edentulous space after orthodontic treatment. PMID:25885663

  14. The dual-zone therapeutic concept of managing immediate implant placement and provisional restoration in anterior extraction sockets.

    PubMed

    Chu, Stephen J; Salama, Maurice A; Salama, Henry; Garber, David A; Saito, Hanae; Sarnachiaro, Guido O; Tarnow, Dennis P

    2012-01-01

    Improvements in implant designs have helped advance successful immediate anterior implant placement into fresh extraction sockets. Clinical techniques described in this case enable practitioners to achieve predictable esthetic success using a method that limits the amount of buccal contour change of the extraction site ridge and potentially enhances the thickness of the peri-implant soft tissues coronal to the implant-abutment interface. This approach involves atraumatic tooth removal without flap elevation, and placing a bone graft into the residual gap around an immediate fresh-socket anterior implant with a screw-retained provisional restoration acting as a prosthetic socket seal device. PMID:22908601

  15. 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

  16. 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. PMID:26647930

  17. 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

  18. 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

  19. Generalized provisional seed zones for native plants.

    PubMed

    Bower, Andrew D; St Clair, J Bradley; Erickson, Vicky

    2014-07-01

    Deploying well-adapted and ecologically appropriate plant materials is a core component of successful restoration projects. We have developed generalized provisional seed zones that can be applied to any plant species in the United States to help guide seed movement. These seed zones are based on the intersection of high-resolution climatic data for winter minimum temperature and aridity (as measured by annual heat : moisture index), each classified into discrete bands. This results in the delineation of 64 provisional seed zones for the continental United States. These zones represent areas of relative climatic similarity, and movement of seed within these zones should help to minimize maladaptation. Superimposing Omernik's level III ecoregions over these seed zones distinguishes areas that are similar climatically yet different ecologically. A quantitative comparison of provisional seed zones with level III ecoregions and provisional seed zones within ecoregions for three species showed that provisional seed zone within ecoregion often explained the greatest proportion of variation in a suite of traits potentially related to plant fitness. These provisional seed zones can be considered a starting point for guidelines for seed transfer, and should be utilized in conjunction with appropriate species-specific information as well as local knowledge of microsite differences. PMID:25154085

  20. 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)

  1. 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

  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. 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. PMID:25659611

  4. Abrasion of restorative materials by toothaste.

    PubMed

    Heath, J R; Wilson, H J

    1976-04-01

    The procedure developed in this investigation is suitable for determining the abrasion resistance of restorative materials to toothbrush/dentifrice abrasion. Ideally, a restoration should have an abrasion resistance similar to that of enamel. Of the materials tested, gold was the only one that wore slightly less than enamel, whilst amalgam wore almost twice as quickly. The silicate material and composites (excluding TD.71) wear away 2-4 times faster than enamel. TD.71 and especially the unfilled resin exhibited very high rates of abrasion. After prolonged toothbrush/dentifrice abrasion, the surfaces of gold and amalgam were considerably smoother than those of the silicate and composite materials. PMID:1066445

  5. 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

  6. Reinforcement of acrylic resins for provisional fixed restorations. Part III: effects of addition of titania and zirconia mixtures on some mechanical and physical properties.

    PubMed

    Panyayong, W; Oshida, Y; Andres, C J; Barco, T M; Brown, D T; Hovijitra, S

    2002-01-01

    Acrylic resins have been used in many different applications in dentistry, especially in the fabrication of provisional fixed partial dentures. Ideally, a provisional crown and bridge material should be easy to handle and should protect teeth against physical, chemical, and thermal injuries. Some of the problems associated with this use are related to the material's poor mechanical properties. It has been demonstrated that acrylic resin can be strengthened through the addition of structural component of different size distributed in the acrylic matrix, thus forming a composite structure. The purpose of this study was to investigate the addition effects of mixtures of titania (titanium dioxide, TiO(2)) powder and zirconia (zirconium dioxide, ZrO(2)) powder being incorporated with pre-polymerized beads mixed in monomer liquid, on some mechanical and physical properties of PMMA resin. The pre-polymerized powder poly(methyl methacrylate) resin was admixed with titania and zirconia powder. A mixing ratio was controlled by volume % of 0, 1.0, 2.0, and 3.0 (samples with 0 v/o served as control groups). For using mixture of titania and zirconia, total amount of the mixture was controlled by volume % of 1.0, 2.0, and 3.0, in which titania and zirconia were mixed at the ratio 1 :1, 1 :2 and 2 :1. Prior to mechanical tests, all rectangular-shaped samples (25 mm x 2 mm x 5 mm) were stored in 37 degrees C distilled water for 7 days after polishing all six sides of samples. Samples were then subjected to the three-point bending flexion test to evaluate the bending strength as well as the modulus of elasticity. Weight gain and exothermic reaction survey were investigated as well. All data were collected and analyzed with one-way analysis of variance (ANOVA) and Sidak method (p=0.05). It was found that the addition of particles generally decreased the water absorbed by the composite system. Only 1 percent by volume concentration of 1 :1 ratio and 2 percent by volume concentration

  7. [Clinical and laboratory studies of bacterial adhesion to validate the choice of material for making provisional dentures for patients with periodontal diseases].

    PubMed

    Ibragimov, T I; Arutiunov, S D; Tsarev, V N; Lebedenko, I Iu; Kraveishvili, S E; Trefilov, A G; Arutiunov, D S; Lomakina, N A

    2002-01-01

    Adhesion of bacteria favoring the development of oral inflammations, including cariesogenic and periodontopathogenic (Actinobacillus actinomycetemcommitans, Streptococcus sanguis, Fusobacterium nucleatum, Staphylococcus warneri) and yeast fungi (Candida albicans), to 13 materials used for making provisional dentures was studied. Adhesion of all the studied bacteria and fungi to Russian material Esterfil Foto was the minimum. Clinical use of this material in patients with chronic generalized periodontitis showed that it was well tolerated and the treatment led to improvement of oral microbiocenosis. PMID:12056141

  8. Sequential provisional implant prosthodontics therapy.

    PubMed

    Zinner, Ira D; Markovits, Stanley; Jansen, Curtis E; Reid, Patrick E; Schnader, Yale E; Shapiro, Herbert J

    2012-01-01

    The fabrication and long-term use of first- and second-stage provisional implant prostheses is critical to create a favorable prognosis for function and esthetics of a fixed-implant supported prosthesis. The fixed metal and acrylic resin cemented first-stage prosthesis, as reviewed in Part I, is needed for prevention of adjacent and opposing tooth movement, pressure on the implant site as well as protection to avoid micromovement of the freshly placed implant body. The second-stage prosthesis, reviewed in Part II, should be used following implant uncovering and abutment installation. The patient wears this provisional prosthesis until maturation of the bone and healing of soft tissues. The second-stage provisional prosthesis is also a fail-safe mechanism for possible early implant failures and also can be used with late failures and/or for the necessity to repair the definitive prosthesis. In addition, the screw-retained provisional prosthesis is used if and when an implant requires removal or other implants are to be placed as in a sequential approach. The creation and use of both first- and second-stage provisional prostheses involve a restorative dentist, dental technician, surgeon, and patient to work as a team. If the dentist alone cannot do diagnosis and treatment planning, surgery, and laboratory techniques, he or she needs help by employing the expertise of a surgeon and a laboratory technician. This team approach is essential for optimum results. PMID:23220306

  9. Native Plant Materials for Sagebrush Steppe Restoration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An increasing number and diversity of plant materials are becoming available for restoration of sagebrush steppe lands. Some species that have previously been available only from wildland harvest are now more economically produced with better seed quality in cultivated fields. Others are now avail...

  10. Mechanical behavior of provisional implant prosthetic abutments

    PubMed Central

    Serra-Pastor, Blanca; Roig-Vanaclocha, Ana; Román-Rodriguez, Juan-Luis; Fons-Font, Antonio

    2015-01-01

    Introduction: Implant-supported prostheses have to overcome a major difficulty presented by the morphology and esthetics of peri-implant tissues in the anterior sector. Diverse therapeutic techniques are used for managing the mucosa adjacent to the implant and the most noteworthy is immediate/deferred fixed provisionalization. Objectives: In vitro testing of strength and deformation of implant prosthetic abutments made from different materials (Titanium/PEEK/methacrylate). Material and Methods: Forty Sweden&Martina® implant prosthetic abutments (n=40) were divided into five groups: Group MP: methacrylate provisional abutments with machined titanium base; Group PP: Poly ether ether ketone (PEEK) provisional abutments; Group TP: titanium provisional abutments; Group TAD: titanium anti-rotational definitive abutments; Group TRD: titanium rotational definitive abutments. Their mechanical behavior under static loading was analyzed. Samples were examined under a microscope to determine the type of fracture produced. Results and Conclusions: Definitive anti-rotational titanium abutments and definitive rotational titanium abutments achieved the best mean compression strength, while PEEK resin provisional abutments obtained the lowest. The group that showed the greatest elastic deformation was the group of titanium provisional abutments. Key words:Immediate loading, immediate provisionalization, implant prosthetic abutment, definitive implant prosthetic abutment. PMID:25129253

  11. 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. PMID:23577553

  12. 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

  13. 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...

  14. Ecologically appropriate plant materials for functional restoration of rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ecosystems of rangelands targeted for restoration have often been modified, hindering restoration efforts. WEhile local adaptation has long been used as an argument for the exclusive use of local plant materials, recent meta-analysis results indicate that general adaptation across a variety of envi...

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

    PubMed Central

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

    2011-01-01

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

  16. 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

  17. 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

  18. 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

  19. 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.

  20. INFLUENCE OF THERMAL STRESS ON MARGINAL INTEGRITY OF RESTORATIVE MATERIALS

    PubMed Central

    Cenci, Maximiliano Sérgio; Pereira-Cenci, Tatiana; Donassollo, Tiago Aurélio; Sommer, Leandro; Strapasson, André; Demarco, Flávio Fernando

    2008-01-01

    The aim of this study was to evaluate the influence of thermal stress on the marginal integrity of restorative materials with different adhesive and thermal properties. Three hundred and sixty Class V cavities were prepared in buccal and lingual surfaces of 180 bovine incisors. Cervical and incisal walls were located in dentin and enamel, respectively. Specimens were restored with resin composite (RC); glass ionomer (GI) or amalgam (AM), and randomly assigned to 18 groups (n=20) according to the material, number of cycles (500 or 1,000 cycles) and dwell time (30 s or 60 s). Dry and wet specimens served as controls Specimens were immersed in 1% basic fuchsine solution (24 h), sectioned, and microleakage was evaluated under x40 magnification. Data were analyzed by Kruskal-Wallis and Mann-Whitney tests: Thermal cycling regimens increased leakage in all AM restorations (p<0.05) and its effect on RC and GI restorations was only significant when a 60-s dwell time was used (p<0.05). Marginal integrity was more affected in AM restorations under thermal cycling stress, whereas RC and GI ionomer restoration margins were only significantly affected only under longer dwell times. PMID:19089200

  1. Directly Placed Restorative Materials: Review and Network Meta-analysis.

    PubMed

    Schwendicke, F; Göstemeyer, G; Blunck, U; Paris, S; Hsu, L-Y; Tu, Y-K

    2016-06-01

    For restoring cavitated dental lesions, whether carious or not, a large number of material combinations are available. We aimed to systematically review and synthesize data of comparative dental restorative trials. A systematic review was performed. Randomized controlled trials published between 2005 and 2015 were included that compared the survival of ≥2 restorative and/or adhesive materials (i.e., no need for restorative reintervention). Pairwise and Bayesian network meta-analyses were performed, with separate evaluations for cervical cavitated lesions and load-bearing posterior cavitated lesions in permanent and primary teeth. A total of 11,070 restorations (5,330 cervical, 5,740 load bearing) had been placed in 3,633 patients in the included trials. Thirty-six trials investigated restoration of cervical lesions (all in permanent teeth) and 36 of load-bearing lesions (8 in primary and 28 in permanent teeth). Resin-modified glass ionomer cements had the highest chance of survival in cervical cavitated lesions; composites or compomers placed via 2-step self-etch and 3-step etch-and-rinse adhesives were ranked next. Restorations placed with 2-step etch-and-rinse or 1-step self-etch adhesives performed worst. For load-bearing restorations, conventional composites had the highest probability of survival, while siloranes were found least suitable. Ambiguity remains regarding which adhesive strategy to use in load-bearing cavitated lesions. Most studies showed high risk of bias, and several comparisons were prone for publication bias. If prioritized for survival, resin-modified glass ionomer cements might be recommended to restore cervical lesions. For load-bearing ones, conventional or bulk fill composites seem most suitable. The available evidence is quantitatively and qualitatively insufficient for further recommendations, especially with regard to adhesive strategies in posterior load-bearing situations. Moreover, different material classifications might yield

  2. Effect of different provisional cement remnant cleaning procedures including Er:YAG laser on shear bond strength of ceramics

    PubMed Central

    Zortuk, Mustafa; Gumus, Hasan Onder; Kilinc, Halil Ibrahim

    2012-01-01

    PURPOSE The purpose of this study was to evaluate the effect of provisional cement removal by different dentin cleaning protocols (dental explorer, pumice, cleaning bur, Er:YAG laser) on the shear bond strength between ceramic and dentin. MATERIALS AND METHODS In total, 36 caries-free unrestored human third molars were selected as tooth specimens. Provisional restorations were fabricated and cemented with eugenol-free provisional cement. Then, disc-shaped ceramic specimens were fabricated and randomly assigned to four groups of dentin cleaning protocols (n = 9). Group 1 (control): Provisional cements were mechanically removed with a dental explorer. Group 2: The dentin surfaces were treated with a cleaning brush with pumice Group 3: The dentin surfaces were treated with a cleaning bur. Group 4: The provisional cements were removed by an Er:YAG laser. Self-adhesive luting cement was used to bond ceramic discs to dentin surfaces. Shear bond strength (SBS) was measured using a universal testing machine at a 0.05 mm/min crosshead speed. The data were analyzed using a Kolmogorov Smirnov, One-way ANOVA and Tukey HSD tests to perform multiple comparisons (α=0.05). RESULTS The dentin cleaning methods did not significantly affect the SBS of ceramic discs to dentin as follows: dental explorer, pumice, cleaning bur, and Er:YAG laser. CONCLUSION The use of different cleaning protocols did not affect the SBS between dentin and ceramic surfaces. PMID:23236570

  3. 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

  4. 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

  5. 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…

  6. Immediate maxillary lateral incisor implants with nonocclusal loading provisional crowns.

    PubMed

    Peñarrocha, Miguel; Lamas, Joana; Peñarrocha, Maria; Garcia, Berta

    2008-01-01

    This clinical report series describes a treatment modality involving immediately placed dental implants in maxillary lateral incisor sites using noncemented immediate provisional crowns retained with calcinable copings (prosthetic complement used in preparing the metal for the definitive prosthesis). Ten implants were placed in eight patients for the replacement of maxillary lateral incisors: two immediate and eight corresponding to cases of agenesis. All were subjected to immediate rehabilitation with provisional acrylic resin crowns in nonocclusal loading. One implant failed 3 weeks after placement due to acute local trauma. The other nine remained functional within the mouth, with normal clinical and radiological characteristics after a minimum of 12-month follow-up. Immediate placement of implant fixed provisional restorations retained by friction in maxillary lateral incisors offers an esthetic solution, eliminates the need for a removable provisional restoration, and avoids implant failures associated with excess cement or screw loosening. Moreover, in the case of extractions, immediate placement and provisionalization of implants in maxillary lateral incisors can effectively optimize the peri-implant esthetic results by maintaining the existing hard and soft tissue architecture of the replaced tooth. As no cement or screws are required, and the provisional crowns are placed in nonocclusal loading, the risk of complications is minimized. PMID:17927733

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

    PubMed

    Zhang, Dongjiao; Chen, Xinmin

    2011-10-01

    All-ceramic crowns and bridges have been widely used for dental restorations owing to their excellent functionality, aesthetics and biocompatibility. However, the premature clinical failure of all-ceramic crowns and bridges may easily occur when they are subjected to the complex environment of oral cavity. In the oral environment, all-ceramic materials are prone to aging. Aging can lead all-ceramic materials to change color, to lower bending strength, and to reduce anti-fracture toughness. There are many factors affecting the aging of the all-ceramic materials, for example, the grain size, the type of stabilizer, the residual stress and the water environment. In order to analyze the aging behavior, to optimize the design of all-ceramic crowns and bridges, and to evaluate the reliability and durability, we review in this paper recent research progress of aging behavior for all-ceramics restoration materials. PMID:22097281

  8. Comparison of the flexural strength of six reinforced restorative materials.

    PubMed

    Cohen, B I; Volovich, Y; Musikant, B L; Deutsch, A S

    2001-01-01

    This study calculated the flexural strength for six reinforced restorative materials and demonstrated that flexural strength values can be determined simply by using physical parameters (diametral tensile strength and Young's modulus values) that are easily determined experimentally. A one-way ANOVA analysis demonstrated a statistically significant difference between the two reinforced glass ionomers and the four composite resin materials, with the composite resin being stronger than the glass ionomers. PMID:12017792

  9. Materials and methods for autonomous restoration of electrical conductivity

    SciTech Connect

    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.

  10. Recommendations for conducting controlled clinical studies of dental restorative materials.

    PubMed

    Hickel, R; Roulet, J-F; Bayne, S; Heintze, S D; Mjör, I A; Peters, M; Rousson, V; Randall, R; Schmalz, G; Tyas, M; Vanherle, G

    2007-03-01

    About 35 years ago, Ryge provided a practical approach to evaluation of 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 non-standard investigator modifications of the categories, scales, and reporting methods, has created a body of literature that is extremely difficult to meaningfully interpret. In many cases, the insensitivity of the original Ryge methods is misinterpreted as good clinical performance. While there are many good features of the original system, it is now time to move 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 clinical trial

  11. 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

  12. Provisional Teacher Program: Implementation Guidelines.

    ERIC Educational Resources Information Center

    New Jersey State Dept. of Education, Trenton.

    These guidelines are offered to public school districts and nonpublic schools to assist in implementing the provisional certification requirements for first year teachers in New Jersey. The guidelines address: (1) membership of the Professional Support Team that provides the training, support, and supervision for provisional teachers; (2) roles…

  13. 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

  14. 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

  15. Fluoride and aluminum release from restorative materials using ion chromatography

    PubMed Central

    OKTE, Zeynep; BAYRAK, Sule; FIDANCI, Ulvi Reha; SEL, Tevhide

    2012-01-01

    Objective The aim of this study was to determine the amounts of fluoride and aluminum released from different restorative materials stored in artificial saliva and double-distilled water. Material and Methods Cylindrical specimens (10 x 1 mm) were prepared from 4 different restorative materials (Kavitan Plus, Vitremer, Dyract Extra, and Surefil). For each material, 20 specimens were prepared, 10 of which were stored in 5 mL artificial saliva and 10 of which were stored in 5 mL of double-distilled water. Concentrations of fluoride and aluminum in the solutions were measured using ion chromatography. Measurements were taken daily for one week and then weekly for two additional weeks. Data were analyzed using two-way ANOVA and Duncan's multiple range tests (p<0.05). Results The highest amounts of both fluoride and aluminum were released by the resin-modified glass ionomer cement Vitremer in double-distilled water (p<0.05). All materials released significantly more fluoride in double-distilled water than in artificial saliva (p<0.05). In artificial saliva, none of the materials were observed to release aluminum. Conclusion It was concluded that storage media and method of analysis should be taken into account when the fluoride and aluminum release from dental materials is assessed. PMID:22437674

  16. 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

  17. 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

  18. 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

  19. 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

  20. Biodegradation and abrasive wear of nano restorative materials.

    PubMed

    de Paula, A B; Fucio, S B P; Ambrosano, G M B; Alonso, R C B; Sardi, J C O; Puppin-Rontani, R M

    2011-01-01

    The purpose of this study was to evaluate the biomechanical degradation of two nanofilled restorative materials (a resin-modified glass ionomer, Ketac N100 and a composite, Filtek Z350), compared with conventional materials (Vitremer and TPH Spectrum). Twenty specimens obtained from each material were divided into two storage groups (n=10): relative humidity (control) and Streptococcus mutans biofilm (biodegradation). After 7 days of storage, roughness values (Ra) and micrographs by scanning electron microscopy (SEM) were obtained. In a second experimental phase, the specimens previously subjected to biodegradation were fixed to the tooth-brushing device and abraded via toothbrushes, using dentifrice slurry (mechanical degradation). Next, these specimens were washed, dried, and reassessed by roughness and SEM. The data were submitted to repeated measures three-way analysis of variance (ANOVA) and Tukey tests (p<0.05). There was statistically significant interaction among factors: material, storage (humidity/biofilm), and abrasion (before/after). After biodegradation (S mutans biofilm storage), Ketac N100 presented the highest Ra values. Concerning bio plus mechanical challenge, TPH Spectrum, Ketac N100, and Vitremer presented the undesirable roughening of their surfaces, while the nano composite Filtek Z350 exhibited the best resistance to cumulative challenges proposed. The degraded aspect after biodegradation and the exposure of fillers after mechanical degradation were visualized in micrographs. This study demonstrated that the nanotechnology incorporated in restorative materials, as in composite resin and resin-modified glass ionomer, was important for the superior resistance to biomechanical degradation. PMID:21913859

  1. Reverse spot bonding: a novel technique for provisionalization with immediate dentin sealing.

    PubMed

    Schoenbaum, Todd R; Ercus, Sebastian; Snowden, John

    2012-05-01

    Described here is a clinical technique for the creation of predictable, stable, and efficient provisionals in combination with the use of immediate dentin sealing for partial-coverage posterior ceramic restorations. PMID:22616222

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

    SciTech Connect

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

    1985-08-01

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

  3. 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

  4. 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

  5. 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.

  6. 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...

  7. 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.

  8. Comparison of wear-resistance of Class V restorative materials.

    PubMed

    Frazier, K B; Rueggeberg, F A; Mettenburg, D J

    1998-01-01

    Compomers and resin-modified glass ionomers have been developed to improve the physical properties of traditional glass ionomer cements. This project compared the toothbrush wear-resistance of three compomers (Compoglass, Dyract, Hytac) and three resin-modified glass ionomer restorative materials (Fuji II LC, Photac-Fil, Vitremer) to that of two resin-based composites (Herculite XRV, Silux Plus). Specimens (n = 7) were prepared according to manufacturers' instructions and stored in a humidor for 48 hours prior to testing. The specimens were subjected to 120,000 strokes at 1.5 Hz, using a brush-head force of 200 g on a Manly V-8 cross-brushing machine. The slurry contained a 50:50 (w/w) mixture of toothpaste and deionized water. Abrasion-resistance was calculated by measuring specimen mass-loss prior to and subsequent to brushing. The data were analyzed using a one-way analysis of variance (ANOVA) and the Tukey-Kramer post-hoc test. Significant differences (p < .0001) in mass-loss were found, and loss ranged from 0.013 +/- 0.003 g (Hytac) to 0.061 +/- 0.009 g (Compoglass). No correlation (p = .959) between wear-resistance and experimentally determined filler content existed. This study showed that all but one hybrid resin-ionomer type material exhibited a resistance to toothbrush wear that was as good as or better than that of the two traditional resin-based composite materials. PMID:10321201

  9. Replacement of a tooth with a fiber-reinforced direct bonded restoration.

    PubMed

    Shuman, I E

    2000-01-01

    Today's methods and materials for tooth replacement are multiple and varied. Modern materials now allow for highly conservative abutment preparations that can retain bonded single tooth replacement fixed prostheses. A case report is presented in which fiber reinforced with composite resin was used for placement of a three-unit fixed long-term provisional restoration, providing fracture resistance while achieving an esthetically pleasing, durable restoration. PMID:11199598

  10. 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...

  11. 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

  12. Compressive fatigue limit of four types of dental restorative materials.

    PubMed

    Chen, Song; Öhman, Caroline; Jefferies, Steven R; Gray, Holly; Xia, Wei; Engqvist, Håkan

    2016-08-01

    The purpose of this study was to evaluate the quasi-static compressive strength and the compressive fatigue limit of four different dental restorative materials, before and after aging in distilled water for 30 days. A conventional glass ionomer cement (Fuji IX GP; IG), a zinc-reinforced glass ionomer cement (Chemfil rock; CF), a light curable resin-reinforced glass ionomer cement (Fuji II LC; LC) and a resin-based composite (Quixfil; QF) were investigated. Cylindrical specimens (4mm in diameter and 6mm in height) were prepared according to the manufacturer׳s instructions. The compressive fatigue limit was obtained using the staircase method. Samples were tested in distilled water at 37°C, at a frequency of 10Hz with 10(5) cycles set as run-out. 17 fatigue samples were tested for each group. Two-way ANOVA and one-way ANOVA followed by Tukey׳s post-hoc test were used to analyze the results. Among the four types of materials, the resin-based composite exhibited the highest compressive strength (244±13.0MPa) and compressive fatigue limit (134±7.8MPa), followed by the light-cured resin reinforced glass ionomer cement (168±8.5MPa and 92±6.6MPa, respectively) after one day of storage in distilled water. After being stored for 30 days, all specimens showed an increase in compressive strength. Aging showed no effect on the compressive fatigue limit of the resin-based composite and the light-cured resin reinforced glass ionomer cement, however, the conventional glass ionomer cements showed a drastic decrease (37% for IG, 31% for CF) in compressive fatigue limit. In conclusion, in the present study, resin modified GIC and resin-based composite were found to have superior mechanical properties to conventional GIC. PMID:27085845

  13. Comparative wear resistance of reinforced glass ionomer restorative materials.

    PubMed

    Yap, A U; Teo, J C; Teoh, S H

    2001-01-01

    This study investigated the wear resistance of three restorative reinforced glass ionomer cements (Fuji IX GP FAST [FJ], Miracle Mix [MM] and Ketac Silver [KS]). Microfilled (Silux [SX]) and mini-filled (Z100 [ZO]) composites were used for comparison. Six specimens were made for each material. The specimens were conditioned for one week in distilled water at 37 degrees C and subjected to wear testing at 20 MPa contact stress against SS304 counterbodies using a reciprocal compression-sliding wear instrumentation. Distilled water was used as lubricant. Wear depth (microm) was measured using profilometry every 2,000 cycles up to 10,000 cycles. Results were analyzed using ANOVA/Scheffe's test (p<0.05). After 10,000 cycles of wear testing, ranking was as follows: KS>ZO>MM>FJ>SX. Wear ranged from 26.1 microm for SX to 71.5 microm for KS. The wear resistance of KS was significantly lower than FJ, MM and SX at all wear intervals. Although KS had significantly more wear than ZO at 2,000 to 6,000 cycles, no significant difference in wear was observed between these two materials at 8,000 and 10,000 cycles. Sintering of silver particles to glass ionomer cement (KS) did not appear to improve wear resistance. The simple addition of amalgam alloy to glass ionomer may improve wear resistance but results in poor aesthetics (silver-black color). FJ, which relies on improved chemistry instead of metal fillers, showed comparable wear resistance to the composites evaluated and is tooth-colored. It may serve as a potential substitute for composites in low-stress situations where fluoride release is desirable and aesthetic requirements are not high. PMID:11504433

  14. 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

  15. 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

  16. 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

  17. 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

  18. A FIELD-TRIAL OF TWO RESTORATIVE MATERIALS USED WITH ATRAUMATIC RESTORATIVE TREATMENT IN RURAL TURKEY: 24-MONTH RESULTS

    PubMed Central

    Ercan, Ertugrul; Dülgergil, Ç. Türksel; Soyman, Mübin; Dalli, Mehmet; Yildirim, Isil

    2009-01-01

    Objective: The purpose of this study was to investigate the clinical performance of high-strength glass ionomer cement (HSGIC) and resin-modified glass ionomer (RMGIC) in single and multiple surface carious cavities in the field conditions. Material and Methods: A split-mouth design, including ninety-one fillings placed on contra lateral molar pairs of 37 children, was used in permanent dentition. As filling materials, a HSGIC (Ketac Molar/3M ESPE) and a RMGIC (Vitremer/ 3M ESPE) were used with the Atraumatic Restorative Treatment (ART). Baseline and 6, 12 and 24-month evaluations of the fillings were made with standard-ART and USPHS criteria by two examiners with kappa values of 0.92 and 0.87 for both criteria. Results: According to the USPHS criteria, the retention rates of RMGIC and HSGIC restorations were 100% and 80.9% for single surface, and 100% and 41.2% for multiple surface restorations after 24 months, respectively. Irrespective of surface number, RMGIC was significantly superior to HSGIC (p= 0.004), according to both standard-ART and USPHS criteria. Conclusion: The results indicate that RMGIC may be an alternative restorative technique in comparison to high-strength GIC applications in ART-field-trials. However, further clinical and field trials are needed to support this conclusion. PMID:19668990

  19. 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

  20. [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

  1. 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…

  2. 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.

  3. Effect of the lasers used in periodontal therapy on the surfaces of restorative materials.

    PubMed

    Hatipoğlu, Mükerrem; Barutcigil, Çağatay; Harorlı, Osman Tolga; Ulug, Bülent

    2016-05-01

    The present study aimed to reveal potential damage of the lasers, which are used as an alternative to manual instruments in periodontal therapy, might cause to the surface of restorative materials. Four different restorative materials were used: a glass-ionomer cement (GIC), a flowable composite (FC), a universal composite (UC) and an amalgam. Ten cylindrical samples (8 mm × 2 mm) were prepared for each restorative material. Two laser systems were used in subgingival curettage mode; an 940 nm diode laser (Epic Biolase, Irvine, CA) and an Er,Cr:YSGG laser (Waterlase iPlus, Biolase, Irvine, CA). After laser irradiation, roughness of the sample surfaces was measured using a profilometer. Additionally, atomic force microscopy (AFM) and scanning electron microscopy (SEM) analyses were performed to evaluate the morphology and surface deformations of the restorative materials and surfaces. The laser irradiation did not affect the surface roughness of any restorative materials relative to that of the control group (p > 0.05) except for the Er,Cr:YSGG treatment on GIC (p < 0.05). SEM and AFM images verified the results of the surface roughness tests. Within the limitations of the present study, it was demonstrated that Er,Cr:YSGG and diode lasers, aside from the Er;Cr:YSGG treatment on GIC, caused no harmful surface effects on adjacent restorative materials. SCANNING 38:227-233, 2016. © 2015 Wiley Periodicals, Inc. PMID:26340579

  4. [Effect of water storage and intrapulpal pressure on microleakage of three restorative materials].

    PubMed

    Balogh, A E; Bouter, D; Fazekas, A; Degrange, M

    2000-09-01

    Three different restorative materials, Z100 composite, F2000 compomer and Vitremer glass ionomer cement are currently proposed for Class V restorations. The aim of this in vitro study was to evaluate the influence of water storage and the simulated intrapulpal pressure (sIP) on the quality of the margins of class V restorations located both in enamel and dentin. The water resorption of restorative materials containing hydrophilic groups (compomers and glass ionomer cements) can favourably modify the marginal sealing ability by hydroscopic expansion. The influence of the sIP was specific to the material. While F2000 compomer and Vitremer glass ionomer cement were un-influenced by sIP, with Z100 composite a significant difference could be observed. It was concluded that F2000 compomer and Vitremer glass ionomer cement showed significantly less microleakage, which means a better marginal sealing ability than Z100 composite. PMID:11057023

  5. Effect of a new resin inlay/onlay restorative material on cuspal reinforcement.

    PubMed

    Lopes, L M; Leitao, J G; Douglas, W H

    1991-08-01

    Nine maxillary premolars were restored with composite resin inlays involving large intracoronal cavity preparations. Buccal and lingual bonded strain guages measured the cuspal flexure under a carefully controlled application of occlusal force. The intact tooth was compared with the corresponding preparation and final restoration. The preparation itself greatly reduced the coronal rigidity, but this was completely recovered in the restored tooth, within the functional force of 111 N. A stiffness ratio showed a 97% recovery. From the point of view of cuspal strength, this may mean that larger intracoronal restorations are feasible with this type of restoration. However, other factors, such as chairside time and complexity, and material properties, such as occlusal wear, have to be taken into consideration. PMID:1882059

  6. 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

  7. 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.

  8. 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. PMID:24773196

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

    PubMed Central

    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. PMID:27347539

  10. Laser equipment for investigation of light distribution in dental tissues and restorative materials

    NASA Astrophysics Data System (ADS)

    Grisimov, Vladimir N.; Smirmov, Alexander V.; Stafeev, Sergey C.

    1997-04-01

    The description of experimental set-up for investigation of light scattering in dental tissue and dental restorative material is presented. The set-up includes the light source (He-Ne laser), beam shaping light polarization control unit and registration device. The latter represents the computer interfaced CCD-camera. The experimental results of side light scattering in enamel/dentin and in double-layer porcelain are represented. The results of this research may be useful for aesthetic dental restorations.

  11. The effect of fiber reinforcement type and water storage on strength properties of a provisional fixed partial denture resin.

    PubMed

    Uzun, Gülay; Keyf, Filiz

    2003-04-01

    Fracture resistance of provisional restorations is an important clinical concern. This property is directly related to transverse strength. Strengthening of provisional fixed partial dentures may result from reinforcement with various fiber types. This study evaluated the effect of fiber type and water storage on the transverse strength of a commercially available provisional resin under two different conditions. The denture resin was reinforced with either glass or aramid fiber or no reinforcement was used. Uniform samples were made from a commercially available autopolymerizing provisional fixed partial denture resin. Sixteen bar-shaped specimens (60 x 10 x 4 mm) were reinforced with pre-treated epoxy resin-coated glass fibers, with aramid fibers, or with no fibers. Eight specimens of each group, with and without fibers, were tested after 24 h of fabrication (immediate group), and after 30-day water storage. A three-point loading test was used to measure the transverse strength, the maximal deflection, and the modulus of elasticity. The Kruskal-Wallis Analysis of Variance was used to examine differences among the three groups, and then the Mann-Whitney U Test and Wilcoxon Signed Ranks Test were applied to determine pair-wise differences. The transverse strength and the maximal deflection values in the immediate group and in the 30-day water storage group were not statistically significant. In the group tested immediately, the elasticity modulus was found to be significant (P = 0.042). In the 30-day water storage group, all the values were statistically insignificant. The highest transverse strength was displayed by the glass-reinforced resin (66.25MPa) in the immediate group. The transverse strength value was 62.04MPa for the unreinforced samples in the immediate group. All the specimens exhibited lower transverse strength with an increase in water immersion time. The transverse strength value was 61.13 MPa for the glass-reinforced resin and was 61.24 MPa for the

  12. Marginal leakage of visible light-cured glass ionomer restorative materials.

    PubMed

    Crim, G A

    1993-06-01

    This study examined the sealing of two visible light-cured glass ionomer restorative materials and a conventional glass ionomer. Class V cavity preparations were completed at the cementoenamel junction on the facial and lingual surfaces of extracted human molars. The cavity preparations were restored with either VariGlass VLC, GC Fuji II LC, or GC Fuji II glass ionomer cements. The restored teeth were thermocycled, immersed in fuchsin dye for 24 hours, sectioned, and evaluated with a measuring microscope. No microleakage occurred at the enamel/glass ionomer or dentin/glass ionomer cement interfaces of any samples, but the enamel adjacent to the VariGlass glass ionomer cement restorations exhibited crazing and staining. PMID:8320640

  13. 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

  14. 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

  15. Antibacterial dental restorative materials: a state-of-the-art review.

    PubMed

    Chen, Liang; Shen, Hong; Suh, Byoung In

    2012-12-01

    This review presents an updated knowledge on the antibacterial dental restorative materials and their performance clinically and in the laboratory. A search of English peer-reviewed dental literature over the last 30 years from PubMed and MEDLINE databases was conducted, and the key words included antibacterial, antimicrobial, dental, primer, adhesive, bonding agent, cement, and composite. Titles and abstracts of the articles listed from search results were reviewed and evaluated for relevancy. In summary, the incorporation of an appropriate amount of antibacterial agent provided dental restorative materials (dental bonding agents, resin composites, resin cements, glass-ionomer cements) antibacterial activity without significantly influencing mechanical properties. PMID:23409624

  16. 49 CFR 385.115 - Reapplying for provisional registration.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Reapplying for provisional registration. 385.115... provisional registration. (a) A Mexico-domiciled motor carrier whose provisional operating authority or provisional Certificate of Registration has been revoked may reapply under part 365 or 368 of this...

  17. 49 CFR 385.115 - Reapplying for provisional registration.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 5 2011-10-01 2011-10-01 false Reapplying for provisional registration. 385.115... provisional registration. (a) A Mexico-domiciled motor carrier whose provisional operating authority or provisional Certificate of Registration has been revoked may reapply under part 365 or 368 of this...

  18. 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

  19. Short-term fluoride release from various aesthetic restorative materials.

    PubMed

    Yap, Adrian U J; Tham, S Y; Zhu, L Y; Lee, H K

    2002-01-01

    The short-term fluoride release of a giomer (Reactmer), a compomer (Dyract AP), a conventional glass ionomer cement (Fuji II Cap) and a resin-modified glass ionomer cement (Fuji II LC) was evaluated and compared. Specimen discs (6 +/-0.2 mm diameter and 1 +/- 0.2 mm thick) were prepared for each material using custom molds. Each disc was placed in 1 ml of deionized for 24 hours at 37 degrees C. After one day, the water was extracted and analyzed. The specimen discs were then re-immersed into another 1 ml of fresh deionized water. The procedure of removing and refilling the water was repeated for 28 days. Sample solutions taken during the first seven days and at days 14, 21 and 28 were introduced into a capillary electrophoresis system using field amplified sample injection (FASI) to determine fluoride release. Data was analyzed using factorial ANOVA/Scheffe's post-hoc test at significance level 0.05. An initial fluoride "burst" effect was observed with glass ionomers. Both compomer and giomer did not show an initial fluoride "burst" effect. With the exception of the compomer, fluoride release at day one was generally significantly greater than at the other time intervals. The glass ionomers released significantly more fluoride than the compomer and giomer at day one. Although fluoride release of the giomer was significantly greater than the other materials at day seven, it became significantly lower at day 28. PMID:12022457

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

    PubMed Central

    Satish, V; Prabhakar, AR; Namineni, Srinivas

    2015-01-01

    ABSTRACT 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

  1. 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

  2. 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

  3. 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.

  4. 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

  5. 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

  6. Radiopacity of different shades of resin-based restorative materials compared to human and bovine teeth.

    PubMed

    Pekkan, Gurel; Ozcan, Mutlu

    2012-01-01

    This study evaluated the radiopacity of different shades of resin-based restorative materials and compared the results to human and bovine dental hard tissues. Disk specimens 6 mm in diameter and 1 mm thick (N = 220, n = 10) were prepared from the following restorative materials: · eight shades of nanofilled composite (Aelite Aesthetic Enamel), · seven shades of nanohybrid composite (Grandio Universal), · six shades of photopolymerized polyacid modified compomer (Glasiosite), and · one shade of hybrid composite (X-tra fil U). Human canine dentin (n = 10), bovine enamel (n = 10), and an aluminum (Al) step wedge were used as references. The optical density values of each material were measured from radiographic images using a transmission densitometer. Al step wedge thickness and optical density values were plotted, and equivalent Al thickness (eq Al) values were determined for radiopacity measurements of each material. The data were analyzed using a non-parametric one-way ANOVA (Kruskal-Wallis), and multiple comparisons were made with a Student-Newman-Keuls post hoc test (a = 0.05). Different shades of resin-based restorative materials tested did not reveal statistically significant differences within each material group (p > 0.05). Radiopacity values of the resin-based restorative materials investigated varied depending on their types; however, within different shades of one material type, radiopacity values were comparable. Every shade of nanocomposite material other than Aelite Aesthetic Enamel Incisal LT Gray showed comparable radiopacity to human dentin. Other materials tested demonstrated higher radiopacity compared to human dentin and bovine enamel. PMID:22782058

  7. Effect of restorative materials and in vitro carious challenge on amalgam margin quality.

    PubMed

    Grossman, E S; Matejka, J M

    1996-09-01

    The surface margin of a restoration is where the restored tooth is subjected to aggressive oral attack. Any resistance to this attack will have favorable consequences on the clinical performance and longevity of the restoration. In this study, Black's class I classic cavity preparations were completed in 120 extracted intact human premolars that were restored with one of two silver amalgams, six different base conditions, and with or without cavity varnish, resulting in 20 different restoration combinations. The cavities were aged for 3 months and 1 year in 1% NaCl at 20 degrees C. A resin cast impression was made of the restoration margin for each specimen. Thereafter 80 restored teeth were subjected to an in vitro bacterial challenge for 36 days. The other 40 specimens were placed in an acidified (pH = 4.0) broth for the same length of time. A second cast impression was then made of the margin of each specimen. The casts were examined with a scanning electron microscope and the widest gap of the margin opening and the length of margin showing a discrepancy were measured. Specimens were ranked first on the basis of the gap size and then on percent of margin discrepancy length. Results were evaluated with one-way ANOVA and Turkey's Student range test with a critical level of statistical significance (p < 0.05). Base type significantly affected aged margin quality. Cariogenic challenge caused a significant breakdown of the amalgam margin although the type of challenge was not significant. A shorter aging time, varnish, and high copper amalgam exacerbated the breakdown. Margin breakdown can be reduced by judicious selection of restoration material combinations. PMID:8887794

  8. 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. PMID:16387356

  9. Effect of Naturally Acidic Agents on Microhardness and Surface Micromorphology of Restorative Materials

    PubMed Central

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

    2011-01-01

    Objectives: This study investigated the titratable acidity and erosive potential of acidic agents on the microhardness and surface micromorphology of four restorative materials. Methods: Forty-seven discs of 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-Ph.D.), 12 mm in diameter and 2.5 mm in thickness, were divided into four groups (5 discs/group). Specimens were then immersed for 7 days into four storage media; deionized water (control), citrate buffer solution, green mango juice and pineapple juice. Microhardness testing before and after immersions was performed. Micromorphological changes were evaluated under a scanning electron microscope (SEM). Statistical significance among each group was analyzed using two-way repeated ANOVA and Tukey’s tests. Results: The Fuji II LC and the Ketac-S showed the highest reduction in microhardness (P<.05). The Valiant-Ph.D. and the Filtek Z250 showed some minor changes over the period of 7 days. The mango juice produced the greatest degradation effect (P<.05). Conclusions: This study suggested that for restorations in patients who have tooth surface loss, materials selected should be considered. In terms of materials evaluated, amalgam and resin composite are the most suitable for restorations. PMID:21311608

  10. The effect of a mouthrinse containing essential oils on dental restorative materials.

    PubMed

    von Fraunhofer, J A; Kelley, J I; DePaola, L G; Meiller, T F

    2006-01-01

    Mouthrinses that contain essential oils are effective for controlling plaque and periodontal disease. Recent studies have shown that such mouthrinses are effective at preventing the formation of biofilm in dental unit waterlines. However, there is no information in the literature regarding the effect of such mouthrinses on restorative materials used within the oral cavity. Specimens of three common restorative materials (a glass ionomer, a composite resin, and amalgam) were subjected to continuous exposure to Listerine and distilled water for 10 days; at that time, the strength, fluid sorption, and surface appearance of the specimens were compared. Specimens of the test materials also were placed in intraoral devices; volunteer patients wore these devices for 12 hours per day for a period of 10 days. During that time, the patients were instructed to rinse twice daily for 30 seconds with Listerine Cool Mint or a non-active mouthrinse. After 10 days, the specimens were salvaged from the devices and inspected by visible and SEM examination. This study indicates that routine use of mouthrinses containing essential oils (or even prolonged exposure to such mouthrinses) has no adverse effects on restorative materials that might be expected to react to such mixtures because of their chemical compositions. It was concluded that active mouthrinses do not appear to have any adverse effects on a variety of restorative biomaterials. PMID:17134077

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

    PubMed

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

    2015-01-01

    Classification systems for all-ceramic materials are useful for communication and educational purposes and warrant continuous revisions and updates to incorporate new materials. This article proposes a classification system for ceramic and ceramic-like restorative materials in an attempt to systematize and include a new class of materials. This new classification system categorizes ceramic restorative materials into three families: (1) glass-matrix ceramics, (2) polycrystalline ceramics, and (3) resin-matrix ceramics. Subfamilies are described in each group along with their composition, allowing for newly developed materials to be placed into the already existing main families. The criteria used to differentiate ceramic materials are based on the phase or phases present in their chemical composition. Thus, an all-ceramic material is classified according to whether a glass-matrix phase is present (glass-matrix ceramics) or absent (polycrystalline ceramics) or whether the material contains an organic matrix highly filled with ceramic particles (resin-matrix ceramics). Also presented are the manufacturers' clinical indications for the different materials and an overview of the different fabrication methods and whether they are used as framework materials or monolithic solutions. Current developments in ceramic materials not yet available to the dental market are discussed. PMID:25965634

  12. 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

  13. 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

  14. 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.

  15. 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

  16. Considerations regarding the optical properties of the composite resin restorative materials.

    PubMed

    Manolea, H; Râcă, R; Coleş, Evantia; Preotu, Gabriela; Mărăşescu, P

    2011-07-01

    The purpose of this study has been to investigate the effects of certain substances frequently used in alimentation on the color stability of the composite resin restorative materials. The research hypothesis was that color stability of the composite resin is affected by the type of composite material used and by the polishing procedure. 14 samples of 5X15X2mm have been prepared from seven universal light curing restorative composite resins. The materials have manipulated and cured using LA 500 Blue Light lamp. A first color determination was done before the introduction of the samples in the dyeing agent with the help of an Easy Shade device. The samples have been splited into two lots each with seven samples. The samples from the first lot have been sectioned into three equal segments. The samples from the second lot have also been sectioned into three equal segments, and in addition to the previous group, their exterior surfaces were processed with a diamond burr. For each type of composite we have introduced a sample in one of the three chosen dyes: red alimentary colorant, coffee and red wine. The color of the samples has been determined again using the Vita Easy Shade device. From clinical point of view the results of this study shows that there are three important factors that matter when we talk about durable aesthetic results: the type of composite resin used for the restoration, the finishing and polishing procedures and the pacients' alimentation habits. The composite resins with a good representation of the anorganic structure are easier to be polished, therefore they have only slight color modifications. Using plastic matrixes for shaping the exterior surface of the restoration is the best solution for obtaining a very smooth surface. The most significant color modifications have been done by the red wine. Coffee and to a smaller extent the red alimentary colorant have modified the color of the restoration material in a smaller degree. PMID:24778835

  17. 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

  18. 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.

  19. Coronal microleakage with five different temporary restorative materials following walking bleach technique: An ex-vivo study

    PubMed Central

    Srikumar, G. P. V.; Varma, K. Ravi; Shetty, K. Harish; Kumar, Pramod

    2012-01-01

    Context: Walking bleach technique uses 30% hydrogen peroxide and sodium perborate, and this paste mixture causes loosening of the coronal temporary restorative materials and thus decreasing its clinical effectiveness and causing irritation to the patients oral tissues. In the present study, sealing ability of hygroscopic coronal temporary restorative materials were compared with the other commonly used temporary restorative materials. Aim: To evaluate the effects of walking bleach material on the marginal sealing ability and coronal microleakage of the hydrophilic temporary restorative materials with that of the other commonly used temporary restorative materials in endodontic practice. Materials and Methods: Seventy-five extracted human maxillary central incisor teeth were prepared chemo-mechanically and obturated with gutta-percha in lateral condensation technique. Surface of each tooth was double coated with cyanoacrylate glue. All the teeth were randomly divided in to five groups. Out of 15 teeth in each group, 10 teeth served as experimental specimens, in which bleaching agent was placed in the pulp chamber and 5 teeth served as control, in which no bleaching agent was placed. The access cavities were restored with temporary restorative materials being tested per each group respectively. The specimens were then immersed in 1% India ink dye and subjected to thermo cycling for 7 days. All the teeth were longitudinally sectioned and observed with stereomicroscope and were graded according to the depth of linear dye penetration. Statistical Analysis Used: Mann-Whitney U test and Kruskal-Wallis test. Results: Hydrophilic temporary restorative materials Cavit G and Coltosol F have shown minimal coronal dye leakage with better sealing ability when exposed to walking bleach paste mixture in the dye penetration tests compared to other commonly used temporary restorative materials. Conclusion: Marginal sealing ability of Cavit G and Coltosol F were not influenced by the

  20. The immediate provisional restoration: a review of clinical techniques.

    PubMed

    Hannon, S M; Breault, L G; Kim, A C

    1998-03-01

    For each patient who requires removal of anterior teeth, there are a multitude of treatment considerations. Cosmetic demands, functional needs, treatment sequencing, timeliness, and affordability are some primary concerns that must be addressed on an individual basis. A patient will generally want a cosmetic and functional prosthesis at the earliest possible opportunity. Providing the most appropriate interim prosthesis for a given patient is both challenging and rewarding. The numerous clinical techniques for immediate interim tooth replacement are reviewed, and previously unreported methods are presented to assist the clinician in the selection of interim prosthesis design. PMID:9643251

  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. 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

  4. 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

  5. 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....

  6. 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....

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

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 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. 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....

  9. 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....

  10. 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

  11. 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…

  12. INTERACTIVE NAME PLACEMENT FOR PROVISIONAL MAPS.

    USGS Publications Warehouse

    Goldberg, Jeffrey L.; Miller, Thomas C.

    1983-01-01

    Computer generation and placement of map type has been refined into a production mode at Mid-Continent Mapping Center (MCMC) for USGS 1:24,000- and 1:25,000-scale Provisional maps. The map collar program is written in FORTRAN using batch processing that allows the program to work in the background.

  13. 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.

  14. Critic appraisal. Postoperative sensitivity with indirect restorations.

    PubMed

    Farias, David; Walter, Ricardo; Swift, Edward J

    2014-01-01

    Postoperative sensitivity is characterized by short and sharp pain, and often experienced after cementation of indirect restorations. Factors associated with the occurrence of post-cementation sensitivity include type of cement, removal of smear layer by acid-etching, aggressive tooth preparation, inadequate provisional restorations, and patient's age. Its prevention is based on either interfering with mechanoreceptor activity or occluding the dentinal tubules. Regarding the latter, application of dentin desensitizers may be effective for blocking the tubules and significantly reducing dentin permeability and consequently postoperative sensitivity. This Critical Appraisal will present available clinical data where traditional materials such as zinc phosphate and glass ionomer cements (GIC) as well as self-adhesive resin-based cements were used. PMID:24761824

  15. Adherence of Streptococcus mutans to Fiber-Reinforced Filling Composite and Conventional Restorative Materials

    PubMed Central

    Lassila, Lippo V.J; Garoushi, Sufyan; Tanner, Johanna; Vallittu, Pekka K; Söderling, Eva

    2009-01-01

    Objectives. The aim was to investigate the adhesion of Streptococcus mutans (S. mutans) to a short glass fibers reinforced semi-IPN polymer matrix composite resin. The effect of surface roughness on adhesion was also studied. For comparison, different commercial restorative materials were also evaluated. Materials and Methods. Experimental composite FC resin was prepared by mixing 22.5 wt% of short E-glass fibers, 22.5 wt% of IPN-resin and 55 wt% of silane treated silica fillers using high speed mixing machine. Three direct composite resins (Z250, Grandio and Nulite), resin-modified glass ionomers (Fuji II LC), amalgam (ANA 2000), fiber-reinforced composite (FRC) (everStick and Ribbond), and pre-fabricated ceramic filling insert (Cerana class 1) were tested in this study. Enamel and dentin were used as controls. The specimens (n=3/group) with or without saliva were incubated in a suspension of S. mutans allowing initial adhesion to occur. For the enumeration of cells on the disc surfaces as colony forming units (CFU) the vials with the microbe samples were thoroughly Vortex-treated and after serial dilutions grown anaerobically for 2 days at +37°C on Mitis salivarius agars (Difco) containing bacitracin. Bacterial adhesion was also evaluated by using scanning electron microscopy. Surface roughness (Ra) of the materials was also determined using a surface profilometer. All results were statistically analyzed with one-way analysis of variance (ANOVA). Results. Composite FC resin and other commercial restorative materials showed similar adhesion of S. mutans, while adhesion to dentin and enamel was significantly higher (p<0.05). Surface roughness had no effect on bacterial adhesion. Saliva coating significantly decreased the adhesion for all materials (p<0.05). Composite FC resin had a significantly higher Ra value than control groups (p<0.05). Conclusions. Short fiber-reinforced composite with semi-IPN polymer matrix revealed similar S. mutans adhesion than

  16. Adherence of Streptococcus mutans to Fiber-Reinforced Filling Composite and Conventional Restorative Materials.

    PubMed

    Lassila, Lippo V J; Garoushi, Sufyan; Tanner, Johanna; Vallittu, Pekka K; Söderling, Eva

    2009-01-01

    OBJECTIVES.: The aim was to investigate the adhesion of Streptococcus mutans (S. mutans) to a short glass fibers reinforced semi-IPN polymer matrix composite resin. The effect of surface roughness on adhesion was also studied. For comparison, different commercial restorative materials were also evaluated. MATERIALS AND METHODS.: Experimental composite FC resin was prepared by mixing 22.5 wt% of short E-glass fibers, 22.5 wt% of IPN-resin and 55 wt% of silane treated silica fillers using high speed mixing machine. Three direct composite resins (Z250, Grandio and Nulite), resin-modified glass ionomers (Fuji II LC), amalgam (ANA 2000), fiber-reinforced composite (FRC) (everStick and Ribbond), and pre-fabricated ceramic filling insert (Cerana class 1) were tested in this study. Enamel and dentin were used as controls. The specimens (n=3/group) with or without saliva were incubated in a suspension of S. mutans allowing initial adhesion to occur. For the enumeration of cells on the disc surfaces as colony forming units (CFU) the vials with the microbe samples were thoroughly Vortex-treated and after serial dilutions grown anaerobically for 2 days at +37 degrees C on Mitis salivarius agars (Difco) containing bacitracin. Bacterial adhesion was also evaluated by using scanning electron microscopy. Surface roughness (Ra) of the materials was also determined using a surface profilometer. All results were statistically analyzed with one-way analysis of variance (ANOVA). RESULTS.: Composite FC resin and other commercial restorative materials showed similar adhesion of S. mutans, while adhesion to dentin and enamel was significantly higher (p<0.05). Surface roughness had no effect on bacterial adhesion. Saliva coating significantly decreased the adhesion for all materials (p<0.05). Composite FC resin had a significantly higher Ra value than control groups (p<0.05). CONCLUSIONS.: Short fiber-reinforced composite with semi-IPN polymer matrix revealed similar S. mutans adhesion

  17. 21 CFR 81.1 - Provisional lists of color additives.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Provisional lists of color additives. 81.1 Section 81.1 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL GENERAL SPECIFICATIONS AND GENERAL RESTRICTIONS FOR PROVISIONAL COLOR ADDITIVES FOR USE IN FOODS, DRUGS, AND COSMETICS § 81.1 Provisional lists...

  18. 48 CFR 232.102-70 - Provisional delivery payments.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Provisional delivery... Item Purchase Financing 232.102-70 Provisional delivery payments. (a) The contracting officer may establish provisional delivery payments to pay contractors for the costs of supplies and services...

  19. 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....

  20. 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....

  1. Molecular Toxicology of Substances Released from Resin–Based Dental Restorative Materials

    PubMed Central

    Bakopoulou, Athina; Papadopoulos, Triantafillos; Garefis, Pavlos

    2009-01-01

    Resin-based dental restorative materials are extensively used today in dentistry. However, significant concerns still remain regarding their biocompatibility. For this reason, significant scientific effort has been focused on the determination of the molecular toxicology of substances released by these biomaterials, using several tools for risk assessment, including exposure assessment, hazard identification and dose-response analysis. These studies have shown that substances released by these materials can cause significant cytotoxic and genotoxic effects, leading to irreversible disturbance of basic cellular functions. The aim of this article is to review current knowledge related to dental composites’ molecular toxicology and to give implications for possible improvements concerning their biocompatibility. PMID:19865523

  2. 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.

  3. Effects of storage media on physical properties of selected tooth coloured restorative materials.

    PubMed

    Sadaghiani, Leili; Adusei, Gabriel; Rees, Jeremy

    2009-09-01

    It is known that storage media can affect the physical properties of some restorative dental materials. The purpose of this laboratory study was to investigate the possible effects of storage media on physical properties of a conventional glass-ionomer, a resin modified glass ionomer and a compomer. Specimens of the restorative materials in the study (FujiII LC, FujiIX and Dyract EXTRA) were prepared. The specimens were stored in either water or artificial saliva with or without exposure to Listerine. The compressive and diametral tensile strength and Vickers hardness of these materials were tested at 24 hours, 1 week, 4 weeks and 12 weeks. Compressive and diametral tensile strength for FujiII LC and Fuji IX had increased at 12 weeks. A decrease was observed for Dyract EXTRA in the same period. No significant differences were observed between the storage media (P > 0.01). Vickers hardness values fluctuated during the testing period, with a pattern being consistent for each material. Storage of materials investigated for the period in this study resulted in superior compressive and diametral tensile strength for Fuji II LC and FujiIX. The opposite was true for Dyract EXTRA. Effects of time were found to be more pronounced than the media (P < 0.01). PMID:19839187

  4. Time-dependent strength and fatigue resistance of dental direct restorative materials.

    PubMed

    Lohbauer, Ulrich; Frankenberger, Roland; Krämer, Norbert; Petschelt, Anselm

    2003-12-01

    Elastic modulus (EM), initial fracture strength (FS) and flexural fatigue limit (FFL) of dental restorative materials were measured in a simulated oral environment to correlate mechanical response under the influence of water with the chemical nature of the test materials under investigation. One resin composite (RC; Tetric Ceram, Ivoclar-Vivadent Corp., Liechtenstein), an ion-leaching resin composite (ILRC; Ariston pHc, Ivoclar-Vivadent Corp., Liechtenstein) a compomer (CO; Dyract AP, Dentsply Corp., USA) and a glass-ionomer cement (GIC; Ketac Molar, 3MEspe Corp., Germany) were tested. Static EM, FS and dynamic FFL experiments were performed. The FFL was determined under cyclic loading for 10(5) cycles in terms of a staircase approach. The materials were stored for 1, 8, 30, 90 and 180 days in 37 degrees C distilled water, respectively. The RC degraded over time due to water adsorption followed by failure within the resin matrix. The ILRC suffered from a pronounced decrease in FS as well as in FFL due to a constant ion-leaching and macroscopic crack growth. CO failed over time due to resin-filler interface cracking. The GIC exhibited improved mechanical performance over time due to a post-hardening mechanism. The results reveal the necessity for substantial preclinical evaluation of direct restorative materials. The material parameters under investigation are capable of predicting clinical performance over time. PMID:15348497

  5. Use of intraoral welding to stabilize dental implants in augmented sites for immediate provisionalization: a case report.

    PubMed

    Avvanzo, Pierluigi; Fabrocini, Lelio A; Ciavarella, Domenico; Avvanzo, Andrea; Lo Muzio, Lorenzo; De Maio, Raffaele A

    2012-02-01

    Immediate implant rehabilitation of edentulous arches may be somewhat problematic because of anatomic situations involving insufficient bone thickness or height and tooth position. The aim of this report was to present a retrospective case series of dental implants placed into augmented sites (split crest or sinus augmentation) that were stabilized with an intraorally welded framework at the time of immediate provisionalization. An intraoral welding unit was used to join and stabilize implants as an orthopedic splint to break down forces applied on provisional restorations during healing and osseointegration. This approach allows for the immediate provisionalization of implants in bone-defective areas where multiple implant systems have been enacted. Forty-eight implants in 16 patients were inserted, welded together to a titanium framework, and immediately provisionalized during the same surgery in which split-crest or sinus augmentation procedures were performed. After removing the welded frameworks, 1 of 48 implants failed; the failed implant was associated with a sinus augmentation procedure. Intraoral welding stabilization may be a predictable procedure to allow immediate loading in augmented areas during healing time and to stabilize implants against nonaxial forces, thereby reducing the number of surgical and prosthetic sessions and making patients comfortable and accustomed to immediate fixed provisional and definitive restorations. PMID:20932150

  6. Erosive Potential of Cola and Orange Fruit Juice on Tooth Colored Restorative Materials

    PubMed Central

    Rajavardhan, K; Sankar, AJS; Kumar, MGM; Kumar, KR; Pranitha, K; Kishore, KK

    2014-01-01

    Background: Erosion is a common condition which manifests due to consumption of high caloric and low pH acidic food stuffs such as carbonated drinks and fruit juices which cause irreversible damage to dental hard tissues and early deterioration of the dental restorations. Aim: The main aim of this study is to evaluate and to compare the erosive potential of carbonated drink (cola) and fruit juice (orange fruit juice) by measuring the surface roughness (Ra) values on two commonly used dental restorative materials. Materials and Methods: A total of 36 specimens each were prepared using both testing materials, compomer (Group I) and giomer (Group II). Six specimens in each group were discarded due to wide variation in pre exposed Ra values and the remaining 30 specimens in each group were further sub divided into 10 samples each according to the testing media used. Immersion regime was followed according to Von Fraunhofer and Rogers. The pre and post immersion surface roughness values were recorded using a profilometer. Results: Both tested materials showed statistically-significant surface erosion (P < 0.01) when exposed to cola and orange fruit juice than the control group (water). Discussion: Compomer showed more surface roughness when compared to giomer when exposed to the three tested media which can be attributed to the variation in filler content, decomposition of resin matrix and fallout of the fillers in composites when exposed to acidic drinks. Other factors responsible for this significant erosion were also discussed. Conclusions: Significant surface changes of the dental restorative materials can take place when exposed to low pH drinks for a prolonged period. PMID:25364590

  7. 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

  8. 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

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

    PubMed Central

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

    2010-01-01

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

  10. 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

  11. 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

  12. 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

  13. 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. PMID:11404871

  14. Investigation of thiol-ene and thiol-ene-methacrylate based resins as dental restorative materials

    PubMed Central

    Cramer, Neil B.; Couch, Charles L.; Schreck, Kathleen M.; Carioscia, Jacquelyn A.; Boulden, Jordan E.; Stansbury, Jeffrey W.; Bowman, Christopher N.

    2009-01-01

    Objectives The objective of this work was to evaluate thiol-norbornene and thiol-ene-methacrylate systems as the resin phase of dental restorative materials and demonstrate their superior performance as compared to dimethacrylate materials. Methods Polymerization kinetics and overall functional group conversions were determined by Fourier transform infrared spectroscopy (FTIR). Flexural strength and modulus were determined with a 3-point flexural test. Polymerization-induced shrinkage stress was measured with a tensometer. Results Thiol-ene polymer systems were demonstrated to exhibit advantageous properties for dental restorative materials in regards to rapid curing kinetics, high conversion, and low shrinkage and stress. However, both the thiol-norbornene and thiol-allyl ether systems studied here exhibit significant reductions in flexural strength and modulus relative to BisGMA/TEGDMA. By utilizing the thiol-ene component as the reactive diluent in dimethacrylate systems, high flexural modulus and strength are achieved while dramatically reducing the polymerization shrinkage stress. The methacrylate-thiol-allyl ether and methacrylate-thiol-norbornene systems both exhibited equivalent flexural modulus (2.1 ± 0.1 GPa) and slightly reduced flexural strength (95 ± 1 and 101 ± 3 MPa, respectively) relative to BisGMA/TEGDMA (flexural modulus; 2.2 + 0.1 GPa and flexural strength; 112 ± 3 MPa). Both the methacrylate-thiol-allyl ether and methacrylate-thiol-norbornene systems exhibited dramatic reductions in shrinkage stress (1.1 ± 0.1 and 1.1 ± 0.2 MPa, respectively) relative to BisGMA/TEGDMA (2.6 ± 0.2 MPa). Significance The improved polymerization kinetics and overall functional group conversion, coupled with reductions in shrinkage stress while maintaining equivalent flexural modulus, result in a superior overall dental restorative material as compared to traditional bulk dimethacrylate resins. PMID:19781757

  15. 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

  16. Restoration of large cranial defect for cranioplasty with alloplastic cranial implant material: a case report.

    PubMed

    Goyal, Shelly; Goyal, Mukesh Kumar

    2014-06-01

    Cranial defects result either from trauma or after intentional osteocraniotomies or external decompression craniectomies. These defects occur most frequently during wartime, but their incidence during peacetime, as a result of accident or disease, makes knowledge of cranioplasty useful to the interested practitioner. Most cranial defects will have some variable proportion of cosmetic and mechanical aspects, and the decision regarding cranioplasty must be influenced by the patient's age, prognosis, activity level and the specific conditions of the scalp and calvarium. This case report is oriented towards post-traumatic restoration of large cranial defect with alloplastic heat-cure poly methyl methacrylate resin material. PMID:24757358

  17. Combined effect of staining substances on the discoloration of esthetic Class V dental restorative materials.

    PubMed

    Lee, Yong-Keun; Powers, John M

    2007-01-01

    The purpose of this study was to determine the combined effect of an organic substance (mucin as a substitute for salivary organic substances), chlorhexidine, and an iron compound/tea solution on the changes in the color of esthetic Class V dental restorative materials. Color of a glass ionomer, resin-modified glass ionomer, compomer and flowable resin composite of A2 shade, respectively, was determined according to the CIELAB color scale relative to the standard illuminant D65. Color was measured at baseline, and after sequential immersion in the following substances: Step-1, mucin in PBS (MCP) for 48 h; Step-2, chlorhexidine (CHX) for 24 h; Step-3, iron compound (IRN) or tea solution (TEA) up to 7 days; and Step-4, ultrasonic cleaning for 1 h. Color change (DeltaE(ab )*) was calculated by the equation: DeltaE(ab)* = [(DeltaL*)(2) + (Deltaa*)(2) + (Deltab*)(2)](1/2), of which DeltaL(*) indicates changes in value, Deltaa(*) indicates changes in red-green parameter and Deltab(*) indicates changes in yellow-blue parameter. DeltaE(ab)* values after immersion in MCP and CHX were compared, and DeltaE(ab)* values after immersion in IRN or TEA, and subsequent ultrasonic cleaning were compared with respect to the restorative material and immersion substance. DeltaE(ab)* and changes in the color parameters (DeltaL(*), DeltaC(ab)* and DeltaH(ab)*) were analyzed by repeated measures, analysis of variance and a post-hoc test at the 0.05 level of significance. Color changes after immersion in MCP were acceptable (DeltaE(ab)* < 3.3), and those after immersion in CHX were generally acceptable. The range of DeltaE(ab)* values after immersion in IRN was 3.1-19.6, and that after ultrasonic cleaning was 2.4-9.6. The range of DeltaE(ab)* values after immersion in TEA was 10.7-21.1, and that after ultrasonic cleaning was 11.9-14.5. Color changes of four Class V restorative materials after combined treatment with mucin, chlorhexidine and an iron compound/tea solution were not acceptable

  18. The effect of three finishing systems on four esthetic restorative materials.

    PubMed

    Hoelscher, D C; Neme, A M; Pink, F E; Hughes, P J

    1998-01-01

    Previous studies have investigated the finishing and smoothness of composite and traditional glass-ionomer restorations, but few have included resin-modified glass-ionomer cements or more recent finishing systems. The results of using three different finishing systems (Sof-Lex, Enhance, finishing burs) on two composites (Silux, Prisma TPH), a traditional glass ionomer (Ketac-Fil), and a resin-modified glass ionomer (Fuji II LC) were studied. Sixty samples were condensed into sectioned acrylic tubes, covered with a Mylar matrix plus a glass slide at each surface, then cured as per the manufacturers' instructions. Samples were randomized to three groups of five for each material and testing with a Surfanalyzer 4000 of unfinished samples (cured with Mylar matrix) was done to obtain baseline average surface roughness (Ra). Samples were then finished as per the manufacturers' instructions using polishing disks, abrasive impregnated disks, and finishing burs before further surface testing. Samples finished with burs and with abrasive impregnated disks were further polished using polishing paste (Prisma Gloss) and again tested. Data were analyzed with ANOVA testing and Tukey's HSD pairwise comparison. Initial testing after randomization to groups showed no significant difference in surface roughness (P = 0.24). Two-factor analysis revealed no significant difference between materials (P = 0.34), a significant difference in method of finish (P < or = 0.00), with no significant interaction between type of material and method of finish (P = 0.11). Aluminum oxide disk and impregnated disk systems provided the best finish for microfilled composite and both glass-ionomer materials (P < or = 0.00). No significant difference in method of finish existed with the hybrid composite (P = 0.07). Overall, esthetic restorative material finishing is best accomplished using abrasive impregnated disks or aluminum oxide disks. Finishing burs gave a significantly rougher surface than the

  19. 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

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

    PubMed

    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 (rCu (2+)=73 pm and rAg (2+)=94 pm), lower mass density (dCu=8.96 g/cm(3) and dAg=10.49 g/cm(3)) 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

  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. Radio-opacity of core materials for all-ceramic restorations.

    PubMed

    Okuda, Yuji; Noda, Makoto; Kono, Hiroshi; Miyamoto, Motoharu; Sato, Hideo; Ban, Seiji

    2010-01-01

    The aim of this study was to investigate and compare the radio-opacity of core materials for all-ceramic restorations, such as zirconia (NANOZR and Y-TZP) and alumina, against commercially pure titanium (cpTi) and aluminum. X-ray images were taken under general settings using an X-ray film. The X-ray film images were scanned using a digital scanner, and the darkness at the central area of each specimen image was quantitatively analyzed using an image analysis software. Amongst the materials investigated, alumina showed the most transparency against X-rays. Conversely, both types of zirconia showed the highest radio-opacity, whereby that of NANOZR was slightly lower than that of Y-TZP. This was because NANOZR contained 30 vol% of alumina and its density was also slightly lower than that of Y-TZP. PMID:20379010

  3. 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. PMID:25764042

  4. A Comparative Evaluation of Marginal Leakage of Different Restorative Materials in Deciduous Molars: An in vitro Study

    PubMed Central

    Rehani, Usha; Rana, Vivek

    2012-01-01

    ABSTRACT Context: Microleakage around dental restorative materials is a major problem in clinical dentistry. Inspite of many new restorative materials available in the market very few actually bond to the tooth surface. Aims: The aims of this study were: (1) To evaluate and compare the marginal leakage of newer restorative materials viz colored compomer, ormocer, giomer and RMGIC in class I restoration of deciduous molars. (2) To compare the microleakage scores between the groups of: Colored compomer and ormocer, giomer and RMGIC, ormocer with giomer and RMGIC, giomer with RMGIC. Materials and methods: A total of 40 primary molars were randomly divided into four groups of 10 each. Class I cavities were prepared and the cavities were restored with colored compomer (Group A), Ormocer (Group B), Giomer (Group C) and RMGIC (Group D). The teeth were thermocycled and subjected to 0.5% basic fuchsin dye penetration followed by sectioning. The cut sections were evaluated under a stereomicroscope and the data was subjected to statistical analysis. Statistical analysis used: Mann-Whitney U test and Student t-test. Results: No significant difference was observed when colored compomer was compared to ormocer, giomer and RMGIC. Ormocer showed significantly lower microleakage when compared to giomer. However, no significant difference was observed when ormocer was compared to RMGIC. No significant difference between giomer and RMGIC was found. Conclusion: Ormocer has proven to be an excellent restorative material as it showed least microleakage followed by colored compomer, giomer and RMGIC in increasing order. How to cite this article: Yadav G, Rehani U, Rana V. A Comparative Evaluation of Marginal Leakage of Different Restorative Materials in Deciduous Molars: An in vitro Study . Int J Clin Pediatr Dent 2012;5(2):101-107. PMID:25206147

  5. 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

  6. 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

  7. 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

  8. 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

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

    PubMed

    Chun, Keyoung Jin; 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

  10. 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

  11. 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

  12. 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

  13. CHIPPING FRACTURE RESISTANCE OF DENTAL CAD/CAM RESTORATIVE MATERIALS: PART I, PROCEDURES AND RESULTS

    PubMed Central

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

    2014-01-01

    Objective The edge chipping test was used to measure the fracture resistance of CAD/CAM dental restoration ceramics and resin composites. Methods An edge chipping machine was used to evaluate six materials including one feldspathic porcelain, two glass ceramics, a filled resin-composite, a yttria-stabilized zirconia, and a new ceramic-resin composite material. Force versus edge distance data were collected over a broad range of forces and distances. Data were analyzed by several approaches and several chipping resistance parameters were evaluated. The effects of using different indenter types were explored. Results The force versus distance trends were usually nonlinear with good fits to a power law equation with exponents usually ranging from 1.2 to 1.9. The order of chipping resistance (from least to greatest) was: feldspathic porcelain and a leucite glass ceramic (which were similar), followed by the lithium disilicate glass ceramic and the two resin composites (which were similar), and finally the zirconia which had the greatest resistance to chipping. Chipping with a Vickers indenter required 28% to 45% more force than with the sharp conical 120° indenter. The two indenters rank materials approximately the same way. The power law exponents were very similar for the two indenters for a particular material, but the exponents varied with material. The Rockwell C indenter gives different power law trends and rankings. Significance Despite the variations in the trends and indenters, simple comparisons between materials can be made by chipping with sharp conical 120° or Vickers indenters at 0.50 mm. Broad distance ranges are recommended for trend evaluation. PMID:24685178

  14. 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. PMID:25703791

  15. Antibacterial effects of hybrid tooth colored restorative materials against Streptococcus mutans: An in vitro analysis

    PubMed Central

    Hotwani, Kavita; Thosar, Nilima; Baliga, Sudhindra; Bundale, Sunita; Sharma, Krishna

    2013-01-01

    Objective: The objective of this study was to evaluate the antibacterial effect of two hybrid restoratives, namely resin modified glass ionomer cement (GC Fuji II™ LC, GC Corporation, Tokyo, Japan) and giomer (Beautifil-II, Shofu Inc., Kyoto, Japan) against Streptococcus mutans [Microbial Type Culture Collection (MTCC), 890]. Materials and Methods: The antibacterial effect was evaluated using an agar diffusion test. The prepared wells in petri dishes were completely filled with chlorhexidine (positive control group), resin modified glass ionomer cement and giomer respectively. Prepared bacterial suspension was poured over the petri dish and was spread evenly using the plate spreader. The culture plates were placed in the incubator for 24 h at 37°C. The antibacterial activity was evaluated after 24 h, 48 h, and 7 days for each group in triplicates. Results and Conclusion: The results of the antibacterial effect of the tested materials were collected, statistically analyzed using the ANOVA test to determine the difference between the mean diameters of the inhibition zone produced. The mean zone of bacterial inhibition was found to be more with the giomer specimens at all time periods. However, this inhibitory activity showed a gradual decrease over a period of 7 days and the maximum inhibition was evident after 24 h with both the test materials. PMID:23956533

  16. 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.

  17. 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

  18. 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

  19. Virginia Tech's Off Campus Provisional Certificate Vocational Education Program.

    ERIC Educational Resources Information Center

    Duenk, Lester G.

    Virginia Tech has implemented an off-campus individualized instruction model for new, inservice, provisional certificate teachers. The program has incorporated several innovations to enhance the quality and efficiency of this approach, which has been practiced in various states for a number of years. The provisional certificate course series…

  20. 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. PMID:27335135

  1. Weight change of various light-cured restorative materials after water immersion.

    PubMed

    Iwami, Y; Yamamoto, H; Sato, W; Kawai, K; Torii, M; Ebisu, S

    1998-01-01

    This study investigated weight changes of various light-cured glass-ionomer cements and other restorative materials during water immersion and compared findings with those of conventional glass-ionomer cement and light-cured resin composites. Three light-cured glass-ionomer cements, two polyacid-modified composite resins, one conventional glass-ionomer cement, and one light-cured composite resin were evaluated in this study. The weight changes of these specimens after water immersion were measured using an electronic analytical balance and adjusted according to water solubility measured at the same time weight change was measured. The results were analyzed by one-way ANOVA and Scheffé's F test at P < 0.05. The weight change of Photac-Fil Aplicap was the largest, and there were significant differences among the materials (P < 0.05). Weight change after 6 weeks' water immersion was noted in the following order: Fuji Ionomer Type II LC, Vitremer, Fuji Ionomer Type II, VariGlass VLC, Geristore V, and Clearfil AP-X. It is suggested that the amount of water sorption of light-cured glass-ionomer cements is greater than that of polyacid-modified composite resins. PMID:9656924

  2. Provisional Advisory Levels (PALs) for phosgene (CG).

    PubMed

    Glass, Dana; McClanahan, Mark; Koller, Loren; Adeshina, Femi

    2009-12-01

    The Provisional Advisory Level (PAL) protocol was applied to estimate inhalation exposure limits for phosgene (CG). 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. For background on the PAL program and a description of the methodology used in deriving PALs, the reader is referred to accompanying papers in this Supplement. Data on humans are limited to occupational exposures or accounts from the use of phosgene as a chemical warfare agent in World War I. 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- and 90-day PAL values are 0.0006 and 0.0012 ppm for the PAL 1 and 2 values, respectively. These inhalation values were also accepted as the 2-year PAL 1 and 2 values because severity of lesions in the key study did not increase when exposures were extended from 4 weeks to 12 weeks. Data were not available for deriving 30-day, 90-day, and 2-year PAL 3 values. PMID:19827940

  3. Plasma damage and restoration of a spin-on organic ultra low-k material (k=2.3)

    NASA Astrophysics Data System (ADS)

    Lukaszewicz, Mikolaj; de Marneffe, Jean-Francois; Wilson, Christopher J.; Zhang, Liping; Peng, Hsin-Ying; Verdonck, Patrick; Baklanov, Mikhail

    2012-10-01

    As interconnect dielectrics, spin-on polymers might offer some advantages over OSG materials. In particular, a lower k-value is possible with less porosity, smaller pore size. They also have greater resistance to plasma damage due to their mono-component nature. However, some chemical modifications during the plasma exposure cannot be avoided. In this work, we study the changes caused by a N2-H2-C2H4 CCP discharge used for damascene patterning, on a spin-on k=2.3 organic low-k material. It is shown that this plasma forms amine and ester groups, leading to hydrophilization and k-value degradation. Several restoration treatments are studied on blanket wafers, trying to restore the chemical composition, minimize the k-value and hydrophilization. Those treatments include exposure to in-situ He-H2 discharge, high temperature He-H2 afterglow and combinations thereof, low- and high-temperature VUV treatments. It is found that the best k-value gain is around 50%, and the most promising repair treatment results from the short exposure to a combination of low temperature in-situ He-H2 discharge and high temperature He-H2 afterglow. Applying such restoration process to an array of 30nm trenches, the integrated k-value showed a gain of 13% in RC constant, indicating efficient restoration to pristine k-value, although the chemical composition was not completely restored in all evaluated conditions.

  4. 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.

  5. 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

  6. The weight change of various light-cured restorative materials stored in water.

    PubMed

    Keyf, Filiz; Yalçin, Filiz

    2005-05-15

    This study investigated weight changes of seven different light-cured composite restorative materials, one polyacid glass ionomer compomer, and one light-cured glass-ionomer cement following short-term and long-term storage in water. Two packable composites, three universal (hybrid) composites, one microglass composite, one polyacid glass ionomer resin composite (compomer), one microhybrid low-viscosity (flowable) composite, and one light cured glass ionomer composite cement were evaluated in this study. The weight changes of these specimens were measured daily (short-term storage), and they were measured after six weeks (long-term storage) using an electronic analytical balance. A significant difference was found in Ionoliner, Dyract AP, Opticor flow, Charisma, and Solitare 2, but no significant difference was found in the others (Filtek Z 250, Filtek P60, TPH Spectrum, and Valux Plus). Weight change showed a tendency to increase with the time of water storage. The greatest weight change occurred in light-cured glass ionomer composite cement (Ionoliner), which is followed in order by the weight changes in Dyract AP, Opticor Flow, Charisma, Solitare 2, Filtek Z250, Filtek P60, TPH Spectrum; Valux Plus had the least amount of change. PMID:15915206

  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. 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.

  9. 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

  10. Bonding of restorative materials to dentine: the present status in Japan.

    PubMed

    Nakabayashi, N

    1985-06-01

    Monomers which promote adhesion not only to enamel but also to dentine have been prepared. They have both hydrophilic and hydrophobic groups. The monomers are 2-hydroxy-3-beta-naphthoxypropyl methacrylate, 2-methacryloxyethyl phenyl hydrogen phosphoric acid and 4-methacryloxyethyl trimellitate anhydride. Chemical reaction between monomers and tooth substrates did not lead to adhesion. Cleaning of the ground tooth surface to remove the smeared layer with aqueous 10 per cent citric acid and 3 per cent ferric chloride solution prior to adhesion is recommended. Then, the lipophilic monomers will promote the inter-penetration of monomers into the hard tissues. The infiltrated methacrylates polymerize there and good adhesion takes place. The layer has good resistance against acid and is, in effect, a resin reinforced dentine and enamel as demonstrated by SEM and TEM. The tensile adhesive strength to the cleaned dentine was 18 MN/m2 and to the enamel 14 MN/m2. On the other hand, the value was reduced to 6 MN/m2 when the dentine had been etched by phosphoric acid or citric acid. The ferric chloride added to the citric acid protected dentinal collagen during demineralization. However, the ferric chloride provided ineffective protection against an acid as strong as phosphoric acid. The high bond strength was not dependent upon interlocking at the dentinal tubules as had been considered previously. The resin reinforced dentine and enamel is a hybrid of natural tissue and artificial material and is valuable in the prevention of secondary caries after restoration. PMID:3894241

  11. 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.

  12. 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. PMID:12677604

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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. PMID:16536192

  18. 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.

  19. Principles of restorative dentistry.

    PubMed

    Banker, T

    1993-08-01

    A great deal of information regarding materials, instrumentation, and techniques used for restorative dentistry can be borrowed from the human dental field. Veterinary restorative dentistry is in its infancy. A thorough knowledge of the commonly used materials and how they can be effectively applied is important. Treatment planning is probably one of the most critical phases of restorative dentistry as is painstaking attention to detail. If the guidelines for restorative dental techniques are followed, failures will be minimal. However, one of the most important points to remember is that the success of a restoration is not determined at the completion of the procedure. A restoration, if properly planned and performed, should last the lifetime of the animal patient. It is very important that veterinary dentists continue to evaluate and assess their restorative work at regular intervals so that restorative failures can be detected early, and so that restorative techniques and materials can be critically evaluated in veterinary patients. PMID:8210800

  20. 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

  1. Effect of a glaze/composite sealant on the 3-D surface roughness of esthetic restorative materials.

    PubMed

    Perez, Cesar dos Reis; Hirata, Raphael Júnior; da Silva, Antonio Henrique Monteiro da Fonseca Thomé; Sampaio, Eduardo Martins; de Miranda, Mauro Sayão

    2009-01-01

    The main goal of the current study was to evaluate the surface roughness of tooth-colored restorative materials after different finishing/polishing protocols, including a liquid polisher (BisCover, BISCO, Schaumburg, IL, USA). The restorative materials tested included two nanofilled resin composites (Filtek Supreme, 3M Dental Products, St Paul, MN, USA and Grandio, Voco, Cuxhaven, Germany), one resin-modified glass ionomer cement (Vitremer, 3M Dental Products) and one conventional glass ionomer cement (Meron Molar ART, Voco). The finishing/polishing methods were divided into five groups: G1 (compression with Mylar matrix), G2 (finishing with diamond burs), G3 (Sof-Lex, 3M Dental Products), G4 (BisCover, BISCO, after diamond burs) and G5 (BisCover after Sof-Lex). Five cylindrical specimens of each material were prepared for each group according to the manufacturer's instructions. The finishing/polishing methods were performed by a single operator in one direction to avoid variations at low speed (15,000 RPM). The surface roughness was evaluated using a 3-D scanning instrument with two parameters considered (Ra and Rz). The data was analyzed using one-way ANOVA followed by a multiple comparison Tukey's test. The results showed that BisCover (BISCO) was capable of reducing surface roughness and provided polished surfaces for all materials, enhancing smoothness over already polished surfaces (Sof-Lex, 3M Dental Products) and achieving polishing after finishing with diamond burs. PMID:19953776

  2. 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

  3. 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

  4. 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

  5. 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

  6. Temperature changes under demineralized dentin during polymerization of three resin-based restorative materials using QTH and LED units

    PubMed Central

    Mousavinasab, Sayed-Mostafa; Moharreri, Mohammadreza; Atai, Mohammad

    2014-01-01

    Objectives Light-curing of resin-based materials (RBMs) increases the pulp chamber temperature, with detrimental effects on the vital pulp. This in vitro study compared the temperature rise under demineralized human tooth dentin during light-curing and the degrees of conversion (DCs) of three different RBMs using quartz tungsten halogen (QTH) and light-emitting diode (LED) units (LCUs). Materials and Methods Demineralized and non-demineralized dentin disks were prepared from 120 extracted human mandibular molars. The temperature rise under the dentin disks (n = 12) during the light-curing of three RBMs, i.e. an Ormocer-based composite resin (Ceram. X, Dentsply DeTrey), a low-shrinkage silorane-based composite (Filtek P90, 3M ESPE), and a giomer (Beautifil II, Shofu GmbH), was measured with a K-type thermocouple wire. The DCs of the materials were investigated using Fourier transform infrared spectroscopy. Results The temperature rise under the demineralized dentin disks was higher than that under the non-demineralized dentin disks during the polymerization of all restorative materials (p < 0.05). Filtek P90 induced higher temperature rise during polymerization than Ceram.X and Beautifil II under demineralized dentin (p < 0.05). The temperature rise under demineralized dentin during Filtek P90 polymerization exceeded the threshold value (5.5℃), with no significant differences between the DCs of the test materials (p > 0.05). Conclusions Although there were no significant differences in the DCs, the temperature rise under demineralized dentin disks for the silorane-based composite was higher than that for dimethacrylate-based restorative materials, particularly with QTH LCU. PMID:25110638

  7. 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.

  8. Developing a provisional and national renal disease registry for Iran

    PubMed Central

    Ajami, Sima; Askarianzadeh, Mahdi; Mortazavi, Mojgan

    2015-01-01

    Background: Disease registry is a database that includes information about people suffering a special kind of disease. The aim of this study was to first identify and compare the National Renal Disease Registry (NRDR) characteristics in some countries with Iran; and second, develop a provisional and NRDR for Iran. Materials and Methods: Retrieval of data of the NRDR was performed by scholars responsible in related agencies, including the Ministry of Health and Medical Education, Renal Disease charity, and data registries in the United States, United Kingdom, Malaysia, and Iran. This research was applied, and the study was descriptive-comparative. The study population consisted of the NRDR in selected countries in which data were collected by forms that were designed according to the study objectives. Sources of data were researchers, articles, books, journals, databases, websites, related documents, and people who are active in this regard, and related agencies, including the Ministry of Health and Medical Education, and patient support charity. The researchers collected data for each country based on the study objectives and then put them in comparative tables. Data were analyzed by descriptive, comparative, and theoretical methods. Results: Most of the renal transplant teams report their own results as a single center experiences. America and Britain have a preeminent national registry of renal disease compared to other countries. Conclusion: Given that control, prevention, and treatment of chronic renal diseases incur high expenses and the disease is one of leading mortality factors in Iran and across the world and since national registry system for chronic renal diseases can provide better tools and strategies to manage and evaluate patients’ characteristics as well as risk factors which eventually leads to making better decisions. PMID:26109970

  9. Comparative Evaluation of Sealing Ability of Four Different Restorative Materials Used as Coronal Sealants: An In Vitro Study

    PubMed Central

    Divya, K T; Satish, G; Srinivasa, T S; Reddy, Veera; Umashankar, K; Rao, B Mohan

    2014-01-01

    Background: The purpose of the present study was to evaluate and compare the sealing ability of glass ionomer cement (GIC), composite resin, gray mineral trioxide aggregate (GMTA) and white mineral trioxide aggregate (WMTA) when placed coronally as double - sealing material over gutta-percha in root canal treated teeth. Materials and Methods: A sample of 70 freshly extracted human single rooted teeth were cleaned, shaped and obturated with gutta-percha and AH Plus. The gutta-percha was reduced to a depth of 4 mm from the cemento enamel junction using hot plugger and standardized access cavities with 4 mm depth were prepared at the coronal ends of the roots. The specimens were randomly divided into four groups containing 15 teeth each depending on the restorations they received in the coronal cavity. A positive control group of five teeth received no restorative barrier over gutta-percha. All root surfaces were covered with two coats of nail varnish, leaving only the access openings uncovered except teeth in the negative control group, which were completely covered with nail varnish. All teeth were immersed in India ink, cleared and observed under stereomicroscope for the depth of dye penetration. Results: The results were tabulated and analyzed using Kruskal–Wallis test and multiple comparison between each group was carried out using Mann-Whitney test. The groups sealed with GMTA and WMTA showed least dye penetration than other groups and the difference was statistically significant. Highest dye penetration was seen with groups sealed with GIC and was statistically significant compared with other three groups. Conclusion: The results showed that the GMTA and WMTA provided significantly better coronal seal when compared to other two restorations. The composite resin also showed significantly better seal than the unsealed group and the group sealed GIC, which showed highest leakage that was equivalent to that of unsealed group. PMID:25214726

  10. 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

    2014-01-01

    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. PMID:25459982

  11. 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... submitted for such use or the Commissioner has been notified of studies underway to establish the safety of... provisionally listed for food, drug, and cosmetic use. Color additive Closing date Food use Drug and...

  12. 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... submitted for such use or the Commissioner has been notified of studies underway to establish the safety of... provisionally listed for food, drug, and cosmetic use. Color additive Closing date Food use Drug and...

  13. 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... submitted for such use or the Commissioner has been notified of studies underway to establish the safety of... provisionally listed for food, drug, and cosmetic use. Color additive Closing date Food use Drug and...

  14. 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... submitted for such use or the Commissioner has been notified of studies underway to establish the safety of... provisionally listed for food, drug, and cosmetic use. Color additive Closing date Food use Drug and...

  15. Broad Classification and the Provisional Nature of Science

    ERIC Educational Resources Information Center

    McCarthy, Susan; Sanders, Martie

    2007-01-01

    This paper proposes the use of a key biological concept--broad classification--to teach the provisional and contested nature of science in school biology curricula. It also examines existing curriculum-related factors which might pose obstacles to implementing such a change. An investigation in South Africa highlights the problems regarding…

  16. 14 CFR 21.223 - Class II provisional airworthiness certificates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Class II provisional airworthiness certificates. 21.223 Section 21.223 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... the aircraft has been issued to the manufacturer. (c) The applicant must submit a statement by...

  17. 14 CFR 21.221 - Class I provisional airworthiness certificates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Class I provisional airworthiness certificates. 21.221 Section 21.221 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... limitations established in §§ 21.81(e) and 91.317 of this subchapter. (b) The manufacturer must hold...

  18. Quantification of organic eluates from polymerized resin-based dental restorative materials by use of GC/MS.

    PubMed

    Michelsen, Vibeke Barman; Moe, Grete; Skålevik, Rita; Jensen, Einar; Lygre, Henning

    2007-05-01

    Residual monomers, additives and degradation products from resin-based dental restorative materials eluted into the oral cavity may influence the biocompatibility of these materials. Emphasis has been placed on studies addressing cytotoxic, genotoxic and estrogenic potential of these substances. A prerequisite for analyzing the potential of exposure to eluted compounds from dental materials is reliable quantification methods, both real time and accelerated measurements. The purpose of the present study was to quantify nine eluates; 2-hydroxyethyl methacrylate (HEMA), hydroquinone monomethyl ether (MEHQ), camphorquinone (CQ), butylated hydroxytoluene (BHT), ethyl 4-(dimethylamino)benzoate (DMABEE), triethylene glycoldimethacrylate (TEGDMA), trimethylolpropane trimethacrylate (TMPTMA), oxybenzone (HMBP) and drometrizole (TIN P) leaching from specimens of four commonly used resin-based dental materials in ethanol and an aqueous solution. All analyses were performed by use of GC/MS, each component was quantified separately and the results presented in microg mm(-2). This study has shown that elution from various materials differs significantly, not only in the types of eluates, but also regarding amounts of total and of single components. A high amount of HMBP, a UV stabilizer with potential estrogenic activity, was detected from one material in both solutions. PMID:17127109

  19. A comparative study of sliding wear of nonmetallic dental restorative materials with emphasis on micromechanical wear mechanisms.

    PubMed

    Dupriez, Nataliya Deyneka; von Koeckritz, Ann-Kristin; Kunzelmann, Karl-Heinz

    2015-05-01

    The purpose of this study is to investigate the in vitro tribological behavior of modern nonmetallic restorative materials. Specimen prepared of IPS e.max Press lithium disilicate glass ceramic, IPS Empress Esthetic leucite-reinforced glass ceramic, Everest ZS Blanks yttria-stabilized zirconia and Lava Ultimate composite were subjected to wear using a wear machine designed to simulate occlusal loads. The wear of the investigated materials and antagonists were evaluated by a three-dimensional surface scanner. The quantitative wear test results were used to compare and rank the materials. Specimens were divided into two groups with steatite and alumina antagonists. For each antagonist material an analysis of variance was applied. As a post hoc test of the significant differences, Tukey's honest significant difference test was used. With steatite antagonist: wear of zirconia < wear of leucite-reinforced ceramic < wear of lithium disilicate ceramic < wear of Lava Ultimate composite. No significant wear difference was found for steatite antagonist. The wear of IPS e.max Press and Lava Ultimate against hard alumina was found to be twice lower as compared to their wear when opposing to steatite. The differences were associated with materials mechanical properties (hardness and fracture toughness) and with materials microstructure. Wear mechanisms are discussed. PMID:25303041

  20. Evaluation of Nystatin Containing Chitosan Hydrogels as Potential Dual Action Bio-Active Restorative Materials: in Vitro Approach

    PubMed Central

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

    2014-01-01

    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. PMID:25459982

  1. 14 CFR 91.317 - Provisionally certificated civil aircraft: Operating limitations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Provisionally certificated civil aircraft... RULES Special Flight Operations § 91.317 Provisionally certificated civil aircraft: Operating limitations. (a) No person may operate a provisionally certificated civil aircraft unless that person...

  2. 14 CFR 91.317 - Provisionally certificated civil aircraft: Operating limitations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Provisionally certificated civil aircraft... RULES Special Flight Operations § 91.317 Provisionally certificated civil aircraft: Operating limitations. (a) No person may operate a provisionally certificated civil aircraft unless that person...

  3. 14 CFR 91.317 - Provisionally certificated civil aircraft: Operating limitations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Provisionally certificated civil aircraft... RULES Special Flight Operations § 91.317 Provisionally certificated civil aircraft: Operating limitations. (a) No person may operate a provisionally certificated civil aircraft unless that person...

  4. 14 CFR 91.317 - Provisionally certificated civil aircraft: Operating limitations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Provisionally certificated civil aircraft... RULES Special Flight Operations § 91.317 Provisionally certificated civil aircraft: Operating limitations. (a) No person may operate a provisionally certificated civil aircraft unless that person...

  5. 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

  6. The Preservation and Restoration of Photographic Materials in Archives and Libraries: A RAMP Study with Guidelines.

    ERIC Educational Resources Information Center

    Hendriks, Klaus B.

    Intended for use by archivists, curators, and others responsible for the acquisition and preservation of documentary materials in photographic form, this publication describes the nature of photographic media and recommended conservation measures. It is noted that the major emphasis is on black-and-white photographic materials, with some…

  7. Novel Dental Restorative Materials having Low Polymerization Shrinkage Stress via Stress Relaxation by Addition-Fragmentation Chain Transfer

    PubMed Central

    Park, Hee Young; Kloxin, Christopher J.; Abuelyaman, Ahmed S.; Oxman, Joe D.; Bowman, Christopher N.

    2012-01-01

    Objectives To produce a reduced stress dental restorative material while simultaneously maintaining excellent mechanical properties, we have incorporated an allyl sulfide functional group into norbornene-methacrylate comonomer resins. We hypothesize that the addition-fragmentation chain transfer (AFCT) enabled by the presence of the allyl sulfide relieves stress in these methacrylate-based systems while retaining excellent mechanical properties owing to the high glass transition temperature of norbornene-containing resins. Methods An allyl sulfide-containing dinorbornene was stoichiometrically formulated with a ring-containing allyl sulfide-possessing methacrylate. To evaluate the stress relaxation effect as a function of the allyl sulfide concentration, a propyl sulfide-based dinorbornene, not capable of addition-fragmentation, was also formulated with the methacrylate monomer. Shrinkage stress, the glass transition temperature and the elastic modulus were all measured. The composite flexural strength and modulus were also measured. ANOVA (CI 95%) was conducted to determine differences between the means. Results Increasing the allyl sulfide content in the resin dramatically reduces the final stress in the norbornene-methacrylate systems. Both norbornene-methacrylate resins demonstrated almost zero stress (more than 96% stress reduction) compared with the conventional BisGMA/TEGDMA 70/30 wt% control. Mechanical properties of the allyl sulfide-based dental composites were improved to the point of being statistically indistinguishable from the control BisGMA-TEGDMA by changing the molar ratio between the methacrylate and norbornene functionalities. Significance The allyl sulfide-containing norbornene-methacrylate networks possessed super-ambient Tg, and demonstrated significantly lower shrinkage stress when compared with the control (BisGMA/TEGDMA 70 to 30 wt%). Although additional development remains, these low stress materials exhibit excellent mechanical

  8. 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

  9. 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

  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. Preparation and provisional certification of NBL Spectrographic Impurity Standards, CRM 123 (1-7) and 124 (1-7)

    SciTech Connect

    Santoliquido, P.M.

    1983-09-01

    This report describes the design, production, and provisional certification of two new certified reference materials (CRMs): CRM No. 123 (1-7), U/sub 3/O/sub 8/ containing 18 trace elements, and CRM No. 124 (1-7), U/sub 3/O/sub 8/ containing 24 trace elements. The elements to be included and concentrations to be used were decided on the basis of information gathered from users of a previous CRM of this type, CRM No. 98 (1-7). The new CRMs were prepared by the addition of trace elements to high purity U/sub 3/O/sub 8/. Provisional certification was accomplished by an interlaboratory program in which four different laboratories analyzed the materials by carrier distillation dc arc emission spectrography.

  12. 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

  13. A clinically focused discussion of luting materials.

    PubMed

    Hill, E E; Lott, J

    2011-06-01

    A luting agent's primary function is to fill the minute void between an indirect restoration (definitive or provisional) and tooth (or implant abutment) and mechanically lock the restoration in place to prevent dislodgement during function. The purpose of this paper is to provide a clinically focused discussion on the broad spectrum of luting materials currently available to help the general practitioner make appropriate choices. Resins are typically formulated for a specific function or restoration and offer strength, aesthetics, flexible working times, and very low solubility yet are technique sensitive, expensive and often hard to clean-up. Glass-ionomers offer good strength and optical properties plus the potential for fluoride release/recharge but may have short working times, are sensitive to moisture or dehydration early on, and take time to fully set. Resin-modified glass-ionomers are hybrid, dual-phase materials which are manipulated like glass-ionomer but set quicker and are stronger. Zinc phosphate cement, used successfully for over a century to lute well-fitting metal and metal-ceramic definitive restorations, is a very inexpensive, rigid material which displays very high early compressive strength yet acidity and solubility can be problems. Polycarboxylate cement (a hybrid of zinc phosphate) has lower compressive strength but high tensile strength and may be less injurious to the pulp. Zinc oxide eugenol and zinc oxide non-eugenol cements typically have good sealing abilities but their relatively low compressive and tensile strengths, inherent brittleness, and high solubility limit usage to provisional restorations or implant supported crowns. Claims for multi-purpose or universal use by manufacturers can be somewhat confusing and overwhelming. Even so, the busy general practitioner must have sufficient knowledge to help choose an appropriate luting agent for each unique clinical situation. PMID:21564117

  14. 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. PMID:27252011

  15. 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

  16. 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.

  17. 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

  18. 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

  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. PMID:17886460

  20. Evaluation of the effect of water on three different light cured composite restorative materials stored in water: an in vitro study.

    PubMed

    Biradar, Basawaraj; Biradar, Sudharani; Ms, Arvind

    2012-01-01

    Objectives. The objective of this in vitro study was to investigate whether weight gain or loss in the three different composites occurs due to water absorption when they are stored in water. Methods. The composite restorative materials selected for this study included a microfine hybrid (Synergy) and two nanofilled composite restorative materials (Ceram X and Filtek Supreme Ultra). Twenty specimens of each material were fabricated of each composite material. Group A: Filtek Supreme Ultra, Group B: Synergy, Group C: Ceram X. Then all the specimens were stored in 10 ml Distilled water containing test tubes and placed in incubator at 37°C for six weeks. The weight changes of these specimens were measured daily for the first week and later once a week for next five weeks by using an electrical analytical balance. Results. The data was analyzed by one-way analysis of variance and Student's t test. All groups showed maximum amount of water absorption in the first week than gradual decrease in the water absorption from the second to the sixth week, as compared to the first week and there is no statistically significant difference between the groups tested. Conclusion. All the composite restorative material absorbs some amount of water. The water absorption of the composite may decrease the physical and mechanical properties of the composites; hence it is necessary to consider the type of the material before starting the treatment. PMID:22315607

  1. 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.

  2. 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

  3. Provisional hourly values of equatorial Dst for 1971

    NASA Technical Reports Server (NTRS)

    Sugiura, M.; Poros, D. J.

    1972-01-01

    Tables and plots of provisional hourly values of the equatorial Dst index for 1971 are given, a table of daily mean Dst values for 1971 is also provided. The base line values for the four observatories, Hermanus, Kakioka, Honolulu, and San Juan, were obtained from extrapolations using the coefficients for the secular variations determined for the previous years. Examining the Dst values for quiet days, the base lines so determined appear to be slightly low, so that the Dst index for quiet periods tends to be high.

  4. 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

  5. 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

  6. The application of time series forecasting methods to an estimation problem using provisional mortality statistics.

    PubMed

    Katzoff, M

    1989-03-01

    Provisional estimates of mortality for selected causes of death are published each month by the National Center for Health Statistics. These estimates are based upon a ten per cent sample of death certificates in the United States. Final mortality results, based upon all the death certificates for a calendar year, are available one to two years after publication of the provisional estimates. This paper explores the potential of time series forecasting techniques for improving mortality estimates by using the correlation structure between the provisional and final series to obtain mortality estimates that are expected to be closer to final values than currently used provisional estimates. PMID:2711064

  7. Bacterial leakage of mineral trioxide aggregate as compared with zinc-free amalgam, intermediate restorative material, and Super-EBA as a root-end filling material.

    PubMed

    Fischer, E J; Arens, D E; Miller, C H

    1998-03-01

    Several dye leakage studies have demonstrated the fact that mineral trioxide aggregate (MTA) leaks significantly less than other root-end filling materials. The purpose of this study was to determine the time needed for Serratia marcescens to penetrate a 3 mm thickness of zinc-free amalgam, Intermediate Restorative Material (IRM), Super-EBA, and MTA when these materials were used as root-end filling materials. Fifty-six, single-rooted extracted human teeth were cleaned and shaped with a series of .04 Taper rotary instruments (Pro-series 29 files). Once the canals were prepared in a crown down approach, the ends were resected and 48 root-end cavities were ultrasonically prepared to a 3 mm depth. The teeth were then steam sterilized. Using an aseptic technique, under a laminar air flow hood, the root-end cavities were filled with amalgam, IRM, Super-EBA, and MTA. Four root-end cavities were filled with thermoplasticized gutta-percha without a root canal sealer and served as positive controls. Another four root-end cavities were filled with sticky wax covered with two layers of nail polish and served as negative controls. The teeth were attached to presterilized (ethylene oxide gas) plastic caps, and the root ends were placed into 12-ml vials of phenol red broth. Using a micropipette, a tenth of a milliliter of S. marcescens was placed into the root canal of each tooth. To test the sterility of the apparatus set-up, the root canals of two teeth with test root-end filling materials and one tooth from the positive and negative control groups were filled with sterile saline. The number of days required for S. marcescens to penetrate the four root-end filling materials and grow in the phenol red broth was recorded and analyzed. Most of the samples filled with zinc-free amalgam leaked bacteria in 10 to 63 days. IRM began leaking 28 to 91 days. Super-EBA began leaking 42 to 101 days. MTA did not begin leaking until day 49. At the end of the study, four of the MTA samples

  8. 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

  9. 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

  10. 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

  11. A comparative study of four coronal obturation materials in endodontic treatment.

    PubMed

    Uranga, A; Blum, J Y; Esber, S; Parahy, E; Prado, C

    1999-03-01

    The aim of this study was to compare, in vitro, the ability of temporary versus permanent materials to seal the access cavity. Eighty human maxillary single-canal teeth were prepared biomechanically and obturated with gutta-percha and an endodontic cement AH Plus, using the warm vertical compaction technique. All access cavities were sealed with 1 of 4 materials (Cavit, Fermit, Tetric, or Dyract). Microleakage was assessed by methylene blue dye penetration. The teeth were submitted to 100 thermocycles, with temperature varying from 0 degree to 55 degrees C. The greatest degree of leakage was observed with the temporary materials (Cavit and Fermit). There was a significant difference (p < 0.05) in leakage between all materials except between Dyract and Tetric. This suggests that it may be more prudent to use a permanent restorative material for provisional restorations to prevent inadequate canal sealing and the resulting risk of fluid penetration. PMID:10321182

  12. 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. PMID:26581762

  13. 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

  14. 14 CFR 21.81 - Requirements for issue and amendment of Class I provisional type certificates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Requirements for issue and amendment of Class I provisional type certificates. 21.81 Section 21.81 Aeronautics and Space FEDERAL AVIATION... Type Certificates § 21.81 Requirements for issue and amendment of Class I provisional type...

  15. 14 CFR 21.83 - Requirements for issue and amendment of Class II provisional type certificates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Requirements for issue and amendment of Class II provisional type certificates. 21.83 Section 21.83 Aeronautics and Space FEDERAL AVIATION... Type Certificates § 21.83 Requirements for issue and amendment of Class II provisional...

  16. 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... check payable to the order of the United States Treasury. 18. Upon provisional acceptance of the... is published in the Federal Register. 19. Upon the Commission's final acceptance of the Agreement...

  17. 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.... 16. Upon provisional acceptance of the Agreement by the Commission, the Agreement shall be placed on.... Upon the Commission's final acceptance of the Agreement and issuance of the final Order,...

  18. 76 FR 55648 - Sunsations Inc., Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-08

    ... COMMISSION Sunsations Inc., Provisional Acceptance of a Settlement Agreement and Order AGENCY: Consumer..., standards, and/or bans enforced and administered by the Commission. 27. Upon provisional acceptance of the... is published in the Federal Register. 28. Upon the Commission's final acceptance of the Agreement...

  19. 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 ...

  20. 76 FR 61042 - Modification of Regulations Regarding the Practice of Accepting Bonds During the Provisional...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-03

    ... Antidumping and Countervailing Duty Investigations, 76 FR 23225 (April 26, 2011) (Proposed Rule). The Proposed... Practice of Accepting Bonds During the Provisional Measures Period in Antidumping and Countervailing Duty... practice of accepting bonds during the provisional measures period in AD and CVD investigations....

  1. 75 FR 1356 - RC2 Corporation, Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-11

    ... From the Federal Register Online via the Government Publishing Office CONSUMER PRODUCT SAFETY COMMISSION RC2 Corporation, Provisional Acceptance of a Settlement Agreement and Order AGENCY: Consumer... settlements which it provisionally accepts under the Consumer Product Safety Act in the Federal Register...

  2. 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…

  3. 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...

  4. An in vitro microleakage study of class V cavities restored with a new self-adhesive flowable composite resin versus different flowable materials

    PubMed Central

    Sadeghi, Mostafa

    2012-01-01

    Background: Regarding the importance of sealing ability of restorative dental materials, this study was done to assess the microleakage of class V cavities restored with a new self-adhesive flowable composite resin and compare to different flowable materials. Materials and Methods: Seventy standardized class V cavities were prepared on the buccal surface of maxillary premolars teeth. The occlusal and the gingival margins of the cavities were located on the enamel and cementum/dentin, respectively. Teeth were randomly assigned into five groups (n = 14) and restored with different flowable materials following the manufacturer's instructions: groups I and II: EMBRACE WetBond flowable composite resin with and without acid etching and bonding agent, respectively; group III: flowable compomer (Dyract Flow); and IV and V: microhybrid (Tetric Flow) and nanofilled (Premise Flowable) flowable composite resins, respectively. After finishing and polishing, the teeth were stored in distilled water at 37°C, thermocycled, coated with nail varnish, and immersed in a basic fuchsin, and then longitudinally sectioned. Dye penetration was examined with a stereomicroscope and scored separately for occlusal and gingival on a 0-3 ordinal scale. Data were analyzed with Kruskal-Wallis, Mann-Whitney and Wilcoxon tests (α=0.05). Results: EMBRACE WetBond with acid etching and bonding agent had significantly less microleakage at the occlusal margins than those without, but not at cervical margins. Also cavities restored with EMBRACE WetBond without acid etching and bonding agent showed significantly greater microleakage scores than other groups at occlusal margin, but there was no significant difference at the cervical margin. Conclusion: The application of acid etching and bonding agent with EMBRACE WetBond provided better occlusal marginal sealing than those without at class V cavities. PMID:23162589

  5. A Technique to Transfer the Emergence Profile Contours of a Provisional Implant Crown to the Definitive Impression.

    PubMed

    Shah, Karnik; Yilmaz, Burak

    2016-01-01

    This clinical report describes a method to create a proper emergence profile and accurately transfer it to the definitive impression, using an indirectly fabricated modified impression post. A provisional screwretained crown was indexed with a polyvinyl siloxane material. An autopolymerizing acrylic resin was used to modify an impression post on the polyvinyl siloxane index, which was then screwed onto the implant for the definitive impression after proper soft tissue healing. The indirectly fabricated modified impression post helped to transfer the contours to the definitive impression with minimal soft tissue irritation. PMID:27004296

  6. 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...

  7. 45 CFR 264.70 - What makes a State eligible to receive a provisional payment of contingency funds?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... provisional payment of contingency funds? 264.70 Section 264.70 Public Welfare Regulations Relating to Public... Contingency Fund? § 264.70 What makes a State eligible to receive a provisional payment of contingency funds? (a) In order to receive a provisional payment of contingency funds, a State must: (1) Be a...

  8. 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. PMID:24025757

  9. 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

  10. 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

  11. A Provisional Gene Regulatory Atlas for Mouse Heart Development

    PubMed Central

    Chen, Hailin; VanBuren, Vincent

    2014-01-01

    Congenital Heart Disease (CHD) is one of the most common birth defects. Elucidating the molecular mechanisms underlying normal cardiac development is an important step towards early identification of abnormalities during the developmental program and towards the creation of early intervention strategies. We developed a novel computational strategy for leveraging high-content data sets, including a large selection of microarray data associated with mouse cardiac development, mouse genome sequence, ChIP-seq data of selected mouse transcription factors and Y2H data of mouse protein-protein interactions, to infer the active transcriptional regulatory network of mouse cardiac development. We identified phase-specific expression activity for 765 overlapping gene co-expression modules that were defined for obtained cardiac lineage microarray data. For each co-expression module, we identified the phase of cardiac development where gene expression for that module was higher than other phases. Co-expression modules were found to be consistent with biological pathway knowledge in Wikipathways, and met expectations for enrichment of pathways involved in heart lineage development. Over 359,000 transcription factor-target relationships were inferred by analyzing the promoter sequences within each gene module for overrepresentation against the JASPAR database of Transcription Factor Binding Site (TFBS) motifs. The provisional regulatory network will provide a framework of studying the genetic basis of CHD. PMID:24421884

  12. 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

  13. Phoneme Restoration.

    ERIC Educational Resources Information Center

    Samuel, Arthur

    1996-01-01

    Notes that phonemic restoration is a powerful auditory illusion. Points out that when part of an utterance is replaced by another sound, listeners perceptually restore the missing speech. Several paradigms measure this illusion and explore its bottom-up and top-down bases. Findings reveal that acoustic properties of the replacement sound strongly…

  14. 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.

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 77 FR 44593 - Burlington Coat Factory Warehouse Corporation, Provisional Acceptance of a Settlement Agreement...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-30

    ... COMMISSION Burlington Coat Factory Warehouse Corporation, Provisional Acceptance of a Settlement Agreement... accepted Settlement Agreement with Burlington Coat Factory Warehouse Corporation, containing a civil... Factory Warehouse Corporation CPSC Docket No. 12-C0008 Settlement Agreement 1. In accordance with...

  1. 76 FR 79656 - E & B Giftware LLC, Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-22

    ...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 accordance with the terms of 16 CFR 1118.20(e). Published below is a provisionally-accepted Settlement Agreement with E & B Giftware LLC, containing a civil penalty of $550,000.00, of which $50,000 shall be suspended, within twenty (20) days......

  2. 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.

  3. 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

  4. 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.

  5. Estimating provisional acceptable residues for extralabel drug use in livestock.

    PubMed

    Baynes, R E; Martín-Jiménez, T; Craigmill, A L; Riviere, J E

    1999-06-01

    In 1996, the United States Congress passed legislation (Animal Medicinal Drug Use Clarification Act, AMDUCA), which allows some veterinary or human drugs to be used off label in food-producing animals. In order to implement this Act and protect the U.S. consumer, tolerances or safe concentrations are required before a withdrawal time can be estimated for extralabel drug use. Use of foreign MRLs to satisfy these data needs may not be applicable because of differences in safety standards between the U.S. and other countries. This paper presents strategies that can be used to derive equivalent safe concentrations, referred to as provisional acceptable residues (PARs), that may then be used to estimate drug withdrawal times. Health-based methods are proposed for calculating a PAR for a tissue. Procedure A partitions 50% of the acceptable daily intake (ADI) to edible tissues and reserves the remainder for milk. Procedure B equally partitions the ADI into all edible tissues. Procedure C partitions 50% of the ADI to milk and equally partitions the remaining 50% ADI into edible tissues. Simulations were performed for florfenicol, tetracycline, dexamethasone, azaperone, ivermectin, eprinomectin, and doramectin. In general, these simulations resulted in derivation of conservative PARs, which did not result in daily intakes of residues greater than the health-based ADI. These simulations demonstrated that provided the safe concentrations or equivalent PARs are based on rigorous toxicology safety data (e.g., NOELs, ADIs), the safety of food animal products will not be compromised. It is proposed that these PARs can be used for estimating withdrawal times after extralabel drug use or inadvertent exposure to an environmental contaminant where no approved withdrawal time exists. Finally, implementing similar transparent methods could have a positive impact on international harmonization and trade. PMID:10388614

  6. 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

  7. 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

  8. 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

  9. Intraoral repair of cosmetic restorations.

    PubMed

    Denehy, G; Bouschlicher, M; Vargas, M

    1998-10-01

    The longevity of porcelain and composite resin restorations can often be prolonged by using sound principles, up-to-date materials, and judicious attention to repair when fracture problems arise. Careful case selection and correct usage of surface treatment agents, followed by the use of a quality bonding system and restorative materials, can result in a repair that exhibits excellent retention and natural color blending. This article outlines procedures and materials to repair both resin composite and porcelain intraorally. PMID:9891653

  10. Restoring proximal caries lesions conservatively with tunnel restorations

    PubMed Central

    Chu, Chun-Hung; Mei, May L; Cheung, Chloe; Nalliah, Romesh P

    2013-01-01

    The tunnel restoration has been suggested as a conservative alternative to the conventional box preparation for treating proximal caries. The main advantage of tunnel restoration over the conventional box or slot preparation includes being more conservative and increasing tooth integrity and strength by preserving the marginal ridge. However, tunnel restoration is technique-sensitive and can be particularly challenging for inexperienced restorative dentists. Recent advances in technology, such as the contemporary design of dental handpieces with advanced light-emitting diode (LED) and handheld comfort, offer operative dentists better vision, illumination, and maneuverability. The use of magnifying loupes also enhances the visibility of the preparation. The advent of digital radiographic imaging has improved dental imaging and reduced radiation. The new generation of restorative materials has improved mechanical properties. Tunnel restoration can be an option to restore proximal caries if the dentist performs proper case selection and pays attention to the details of the restorative procedures. This paper describes the clinical technique of tunnel restoration and reviews the studies of tunnel restorations. PMID:24019754

  11. 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…

  12. 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

  13. 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

  14. 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.

  15. Prosthetic procedures for optimal aesthetics in single-tooth implant restorations: a case report.

    PubMed

    Donitza, A

    2000-05-01

    Restoration of a single-tooth implant in the anterior maxilla requires a multidisciplinary approach throughout the treatment and proper communication between the clinician and laboratory technician. Although surgical procedures have an important role in the manipulation of the soft tissues, it is often necessary to perform final contouring of the soft tissue through the provisionalization stage. Unless the soft tissue contour supports the definitive restoration, the treatment is considered a failure. This article reviews various prosthetic procedures that influence the soft tissue contour and establish aesthetics for implant-supported restorations. PMID:11404858

  16. 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

  17. 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.…

  18. 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

  19. Self-healing efficiency of cementitious materials containing microcapsules filled with healing adhesive: mechanical restoration and healing process monitored by water absorption.

    PubMed

    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

  20. 80 FR 45206 - Notice of LG Electronics Tianjin Appliance Co., Ltd. and LG Electronics USA Inc., Provisional...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2015-07-29

    ... LG Electronics USA Inc. A footnote was omitted from the SUMMARY paragraph of the document. FOR... COMMISSION Notice of LG Electronics Tianjin Appliance Co., Ltd. and LG Electronics USA Inc., Provisional... a document in the Federal Register of July 24, 2015, concerning the provisional acceptance of...

  1. 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...

  2. 78 FR 3883 - The Bon-Ton Stores, Inc., Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-17

    ... COMMISSION The Bon-Ton Stores, Inc., Provisional Acceptance of a Settlement Agreement and Order AGENCY... violated CPSA's reporting requirements. 18. Upon provisional acceptance of the Agreement by the Commission... with 16 CFR 1118.20(f). 19. Upon the Commission's final acceptance of the Agreement and issuance of...

  3. 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...

  4. Presentation of two cases of immediate restoration of implants in the esthetic region, using facilitate software and guides with stereolithographic model surgery prior to patient surgery.

    PubMed

    Kamposiora, Phophi; Papavasiliou, George; Madianos, Phoebous

    2012-02-01

    Improvements in both implant microsurfaces and placement techniques have reduced healing time and increased survival rates. CAD/CAM technology and improved ceramic materials allow for achievement of improved esthetics at the implant restoration level. Two clinical procedures have the capacity to decrease patient postoperative discomfort and improve esthetics. Flapless surgery reduces surgical trauma and postoperative problems. Placement of the final prosthetic abutment at the time of implant placement stabilizes soft tissue adhesion and position to the implant. Both results require careful presurgical planning with precise implant and abutment placement. This is a clinical report of two cases that are part of a larger ongoing clinical trial of 20 patients. The inclusion criterion was that patients should be missing a single tooth in the esthetic zone. Facilitate™ software was used in conjunction with dicom files transferred from CT scans for diagnosis. Stereolithographic models and surgical guides were fabricated from the digital information. Surgical guides were used preoperatively so implant replicas could be placed in stereolithographic models as simulated surgery. A ZirDesign™ ceramic abutment was adapted on the model, and a provisional crown was fabricated. At the time of actual implant surgery, the same surgical guide was used with a flapless approach. The previously modified ceramic abutment was screw-retained and torqued to place into the implant. The provisional crown was then cemented after blocking out the screw access hole. A final restoration was fabricated from all-ceramic material after several months. Success requires careful patient selection and attention to each step of the technique. Preliminary outcomes from the ongoing clinical trial are promising. PMID:22050241

  5. 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

  6. 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. PMID:9823086

  7. 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.

  8. 20 CFR 404.1592e - How do we determine provisional benefits?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... monthly provisional benefit amount equal to the last monthly benefit payable to you during your prior... amount under § 404.270. The last monthly benefit payable is the amount of the monthly insurance benefit... other factors for possible reinstatement (i.e., his prior entitlement was terminated within the last...

  9. 38 CFR 17.65 - Approvals and provisional approvals of community residential care facilities.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... approvals of community residential care facilities. 17.65 Section 17.65 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS MEDICAL Community Residential Care § 17.65 Approvals and provisional approvals of community residential care facilities. (a) An approval of a facility meeting all...

  10. 38 CFR 17.65 - Approvals and provisional approvals of community residential care facilities.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... approvals of community residential care facilities. 17.65 Section 17.65 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS MEDICAL Community Residential Care § 17.65 Approvals and provisional approvals of community residential care facilities. (a) An approval of a facility meeting all...

  11. 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

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR 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),...

  12. 31 CFR 240.6 - Provisional credit; first examination; declination; final payment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance: Treasury 2 2014-07-01 2014-07-01 false Provisional credit; first examination; declination; final payment. 240.6 Section 240.6 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE, DEPARTMENT OF THE TREASURY BUREAU OF THE FISCAL SERVICE INDORSEMENT AND PAYMENT OF CHECKS DRAWN ON...

  13. ELECTRON MICROSCOPE MEASUREMENT OF AIRBORNE ASBESTOS CONCENTRATIONS - A PROVISIONAL METHODOLOGY MANUAL

    EPA Science Inventory

    This manual describes a provisional optimum electron microscope (EM) procedure for measuring the concentration of asbestos in air samples. The main features of the method include depositing an air sample on a polycarbonate membrane filter, examining an EM grid specimen in a trans...

  14. ELECTRON MICROSCOPE MEASUREMENT OF AIRBORNE ASBESTOS CONCENTRATIONS. A PROVISIONAL METHODOLOGY MANUAL

    EPA Science Inventory

    This manual describes a provisional optimum electron microscope (EM) procedure for measuring the concentration of asbestos in air samples. The main features of the method include depositing an air sample on a polycarbonate membrane filter, examining an EM grid specimen in a trans...

  15. Radiation safety of crew and passengers of air transportation in civil aviation. Provisional standards

    SciTech Connect

    Aksenov, A.F.; Burnazyan, A.I.

    1985-03-01

    The purpose and application of the provisional standards for radiation safety of crew and passengers in civil aviation are given. The radiation effect of cosmic radiation in flight on civil aviation air transport is described. Standard levels of radiation and conditions of radiation safety are discussed.

  16. Radiation safety of crew and passengers of air transportation in civil aviation. Provisional standards

    NASA Technical Reports Server (NTRS)

    Aksenov, A. F.; Burnazyan, A. I.

    1985-01-01

    The purpose and application of the provisional standards for radiation safety of crew and passengers in civil aviation are given. The radiation effect of cosmic radiation in flight on civil aviation air transport is described. Standard levels of radiation and conditions of radiation safety are discussed.

  17. 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…

  18. 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...

  19. 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...

  20. 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…

  1. 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...

  2. 78 FR 535 - Provisional Unlawful Presence Waivers of Inadmissibility for Certain Immediate Relatives

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-03

    ...On April 2, 2012, U.S. Citizenship and Immigration Services (USCIS) published a proposed rule to amend its regulations to allow certain immediate relatives of U.S. citizens who are physically present in the United States to request provisional unlawful presence waivers prior to departing from the United States for consular processing of their immigrant visa applications. This final rule......

  3. 78 FR 14080 - Kolcraft Enterprises, Inc., Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-04

    ... COMMISSION Kolcraft Enterprises, Inc., Provisional Acceptance of a Settlement Agreement and Order AGENCY... Agreement with Kolcraft Enterprises, Inc., containing a civil penalty of $400,000.00, within twenty (20...), and 16 CFR 1118.20, Kolcraft Enterprises, Inc. (Kolcraft) and staff (staff) of the United...

  4. 76 FR 58784 - Bad Boy Enterprises, LLC, Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-22

    ... From the Federal Register Online via the Government Publishing Office CONSUMER PRODUCT SAFETY...: 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...

  5. 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

    ... From the Federal Register Online via the Government Publishing Office CONSUMER PRODUCT SAFETY...: 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...

  6. 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...

  7. 77 FR 4023 - Hewlett-Packard Company, Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-26

    ...: 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.... Between March 2007 and April 2007, HP conducted a study, from which it obtained additional...

  8. 76 FR 49751 - Perfect Fitness, Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-11

    ... 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... death, and denies that it knowingly violated the reporting requirements of Section 15(b) of the CPSA,...

  9. 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....

  10. 76 FR 6453 - Raynor Marketing, Ltd., Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-04

    ...: 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... create an unreasonable risk of serious injury or death, and denies that it violated the...

  11. 78 FR 27190 - Williams-Sonoma, Inc., Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-09

    ... 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..., where it was hidden from view, there sometimes was no outward indication to consumers that the wood...

  12. 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

    ...: 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... filed a Supplemental Full Report in which it reported that the Firm had received at least 28...

  13. 75 FR 26939 - Target Corporation: Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-13

    ... 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..., 2006, Target submitted a Full Report to CPSC containing information that it had commissioned...

  14. 76 FR 41487 - Macy's, Inc., Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-14

    ... 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... agrees that it will not seek or accept, directly or indirectly, indemnification, reimbursement,...

  15. 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,...

  16. 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...

  17. 14 CFR 91.317 - Provisionally certificated civil aircraft: Operating limitations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Provisionally certificated civil aircraft: Operating limitations. 91.317 Section 91.317 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... type or supplemental type certification of that aircraft; (2) For training flight crews,...

  18. 31 CFR 240.6 - Provisional credit; first examination; declination; final payment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... substitute check, Treasury has a warranty or indemnity claim arising under 12 CFR 229.52 or 229.53. (d... 31 Money and Finance:Treasury 2 2011-07-01 2011-07-01 false Provisional credit; first examination... credit; first examination; declination; final payment. (a) Any credit issued by a Federal Reserve Bank...

  19. 31 CFR 240.6 - Provisional credit; first examination; declination; final payment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... substitute check, Treasury has a warranty or indemnity claim arising under 12 CFR 229.52 or 229.53. (d... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Provisional credit; first examination... credit; first examination; declination; final payment. (a) Any credit issued by a Federal Reserve Bank...

  20. FTIR investigation of monomer polymerisation and polyacid neutralisation kinetics and mechanisms in various aesthetic dental restorative materials.

    PubMed

    Young, A M; Rafeeka, S A; Howlett, J A

    2004-02-01

    Diamond ATR FTIR has been used to quantify light catalysed polymerisation and polyacid neutralisation rates in various glass ionomer cements (GIC), resin-modified GICs (RMGIC) and compomers. At 150s after the start of light exposure, levels of methacrylate polymerisation on the lower surfaces of 1mm thick specimens were 97% and 98% for the RMGIC, Vitremer and Fuji II LC and 47% and 37% for the compomers, Compoglass and Dyract. After light exposure, polymerisation rates for the compomers decreased linearly with inverse time. By 50,000s Compoglass and Dyract were 62% and 51% polymerised. Initial rate of polyacid neutralisation in the GIC Shofu HIFI was 0.32 times that of Fuji IX GIC. Those in Vitremer, Fuji II LC, Compoglass and Dyract were 0.16, 0.09, 0.004 and 0.004 times that of Fuji IX. Excluding short initial periods, log of neutralisation rates decreased linearly with log-time. Average gradients were -1.35 for the GIC, -0.80 for the RMGIC and -0.59 for the compomers. By 50,000s, polyacid salt concentrations for the RMGIC and compomers were 0.41 and 0.016 times that of the GIC. Reaction mechanisms have been discussed and used to help interpret material mechanical properties, fluoride release rates and adhesion to tooth structure. PMID:14609671

  1. Comparison of The Effect of Implant Abutment Surface Modifications on Retention of Implant-Supported Restoration with A Polymer Based Cement

    PubMed Central

    Sahu, Nabaprakash; Lakshmi, Namratha; Azhagarasan, N.S.; Agnihotri, Yoshaskam; Rajan, Manoj; Hariharan, Ramasubramanian

    2014-01-01

    Background: In cement-retained implant-supported restoration it is important to gain adequate retention of definitive restoration as well as retrievability of prosthesis. The surface of the abutment, alloy of the restoration and the type of cement used influences the retention of the restoration. There is a need to analyze the influence of surface modifications of abutments on the retentive capabilities of provisional implant cements. Purpose of study: To compare the effect of implant abutment surface modifications on retention of implant-supported restoration cemented with polymer based cement. Materials and method: Thirty solid titanium implant abutments (ADIN), 8mm height, were divided into 3 groups. Ten abutments with retentive grooves (Group I) as supplied by the manufacturer, Ten abutments milled to 20 taper circumferentially (Group II), and Ten abutments milled and air-abraded with 110 μm aluminum oxide (Group III) were used in this study. Ni-Cr coping were casted for each abutment and polymer based cement was used to secure them to the respective abutments. Using a universal testing machine at a crosshead speed of 0.5 cm/minute, tensile bond strength was recorded (N). Results: Mean tensile bond strength of Group I, II and III were found to be 408.3, 159.9 and 743.8 Newton respectively. The values were statistically different from each other (p<0.001). Conclusion: Abutments with milled and sandblasted surface provide the highest retention followed by abutments with retentive grooves and then by abutments with milled surface when cast copings were cemented to implant abutments with polymer based cement. Clinical implications: Retention of restoration depends on the surface of the abutment as well as the luting agents used. Incorporation of retentive grooves or particle abrasion can enhance retention especially in situation of short clinical crown. PMID:24596785

  2. 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. PMID:26685471

  3. Provisional Guidance for Quantitative Risk Assessment of Polycyclic Aromatic Hydrocarbons

    EPA Science Inventory

    Polycyclic Aromatic Hydrocarbons (PAHs) are products of incomplete combustion of organic materials; sources are, thus, widespread,including cigarette smoke, municipal waste incineration, wood stove emissions, coal conversion, energy production form fossil fuels, and automobile an...

  4. Final environmental assessment and Finding-of-No-Significant-Impact - drum storage facility for interim storage of materials generated by environmental restoration operations

    SciTech Connect

    Not Available

    1994-09-01

    The Department of Energy (DOE) has prepared an Environmental Assessment (EA), DOE/EA-0995, for the construction and operation of a drum storage facility at Rocky Flats Environmental Technology Site, Golden, Colorado. The proposal for construction of the facility was generated in response to current and anticipated future needs for interim storage of waste materials generated by environmental restoration operations. A public meeting was held on July 20, 1994, at which the scope and analyses of the EA were presented. The scope of the EA included evaluation of alternative methods of storage, including no action. A comment period from July 5, 1994 through August 4, 1994, was provided to the public and the State of Colorado to submit written comment on the EA. No written comments were received regarding this proposed action, therefore no comment response is included in the Final EA. Based on the analyses in the EA, DOE has determined that the proposed action would not significantly affect the quality of the human environment within the meaning of the National Environmental Policy Act of 1969 (NEPA). Therefore, preparation of an Environmental Impact Statement is not required and the Department is issuing this Finding of No Significant Impact.

  5. 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.

  6. 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

  7. Ormocer: An aesthetic direct restorative material; An in vitro study comparing the marginal sealing ability of organically modified ceramics and a hybrid composite using an ormocer-based bonding agent and a conventional fifth-generation bonding agent

    PubMed Central

    Kalra, Sarika; Singh, Arundeep; Gupta, Manish; Chadha, Vandana

    2012-01-01

    Aims and Objectives: To compare the marginal sealing ability of ormocer with a hybrid composite using an ormocer based bonding agent and a conventional fifth generation bonding agent. Materials and Methods: Fifty four human premolars were randomly distributed into four test groups of 12 teeth each and two control groups of 3 teeth each. Class I occlusal preparation of 1.5 mm depth were made in each tooth. These were restored using the adhesive and restorative material according to the group. The restorations were finished using a standard composite finishing and polishing kit. Thermocycling between 5° C and 55°C was carried out. Having blocked the root apex and the entire tooth surface except 1 mm around the restoration margin, the teeth were immersed in 2% methylene blue for 48 hours, after which the dye penetration through the margins of each sample was studied under a stereomicroscope. Results and Discussion: Group IV (Admira with Admira Bond) showed the minimum marginal leakage with a mean of 0.200 mm. Four samples in this group showed no microleakage at all and a maximum of 0.400 mm was seen in one sample. Group II (Spectrum TPH with Admira Bond) showed the maximum leakage with a mean of 0.433 mm. One sample showed as much as 1.00 mm of microleakage. Admira when used with Admira Bond showed lesser microleakage than Spectrum TPH used with Prime & Bond NT, the difference being statistically insignificant. PMID:22557897

  8. 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

  9. Provisional pin fixation can maintain reduction in A3 intertrochanteric fractures.

    PubMed

    Cho, Jae-Woo; Kim, Hyung-Jin; Kim, Jinil; Cho, Won-Tae; Jeong, Chan-Dong; Oh, Jong-Keon

    2016-07-01

    A3 intertrochanteric fracture has a higher incidence of intraoperative re-displacement than A1 and 2. The authors have also experienced difficulty with maintenance of reduction in A3 intertrochanteric fractures, as the technique depends on manual effort and can fail easily during the procedure. It induced us to develop this surgical technique to ease the surgical procedure and improve clinical outcomes. This paper introduces a modified provisional guide pin fixation technique applicable to even AO/OTA A3 intertrochanteric fractures, and presents preliminary results of 11 patients who were treated by provisional pin fixation-assisted nailing in A3 intertrochanteric fractures. Using this technique, we have reduced the chances of intraoperative reduction loss and achieved favorable clinical outcomes. PMID:27245452

  10. 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

  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. Immediate provisionalization of dental implants placed in fresh extraction sockets using a flapless technique.

    PubMed

    Crespi, Roberto; Capparè, Paolo; Gherlone, Enrico; Romanos, George

    2012-02-01

    The aim of this clinical study was to evaluate the 24-month clinical outcomes of immediate provisionalization of dental implants placed in fresh extraction sockets using a flapless technique. Fifteen patients were included under strict inclusion and exclusion criteria. All patients required one or two teeth to be extracted for lesions with a hopeless prognosis in the maxillary monoradicular or first premolar region. Twenty implants were placed immediately after tooth extraction, and immediate provisionalization was performed. Sixteen implants had a diameter of 5 mm, and four implants had a diameter of 3.80 mm, all with a 13-mm length. After 24 months of follow-up, a cumulative survival rate of 100% was reported for all implants. Modified Bleeding Index (mBI), modified Plaque Index (mPI), probing depth (PD), marginal gingiva level (MGL), and keratinized mucosa (KM) remained stable for up to 24 months. Mean MGL at 24 months was 0.22 ± 0.15 mm; no significant changes occurred in MGL between baseline and 24 months. Mean KM remained stable from baseline to 24 months. At 24 months, a mean bone loss of 0.83 ± 0.52 mm was measured. The results of this study indicate that flapless surgery for immediately provisionalized implants placed in fresh extraction sockets provides soft tissue and marginal bone maintenance for up to 24 months of follow-up. PMID:22254223

  13. Randomized trial on routine vs. provisional T-stenting in the treatment of de novo coronary bifurcation lesions

    PubMed Central

    Ferenc, Miroslaw; Gick, Michael; Kienzle, Rolf-Peter; Bestehorn, Hans-Peter; Werner, Klaus-Dieter; Comberg, Thomas; Kuebler, Piotr; Büttner, Heinz Joachim; Neumann, Franz-Josef

    2008-01-01

    Aims We investigated whether routine T-stenting reduces restenosis of the side branch as compared with provisional T-stenting in patients with de novo coronary bifurcation lesions. Methods and results Our randomized study assigned 101 patients with a coronary bifurcation lesion to routine T-stenting with sirolimus-eluting stents (SES) in both branches and 101 patients to provisional T-stenting with SES placement in the main branch followed by kissing-balloon angioplasty and provisional SES placement in the side branch only for inadequate results. Primary endpoint was per cent diameter stenosis of the side branch at 9 month angiographic follow-up. Angiographic follow-up in 192 (95%) patients revealed a per cent stenosis of the side branch of 23.0 ± 20.2% after provisional T-stenting (19% with side-branch stent) and of 27.7 ± 24.8% (P = 0.15) after routine T-stenting (98.2% with side-branch stent). The corresponding binary restenosis rates were 9.4 and 12.5% (P = 0.32), prompting re-intervention in 5.0 and 7.9% (P = 0.39), respectively. In the main branch, binary restenosis rates were 7.3% after provisional and 3.1% after routine T-stenting (P = 0.17). The overall 1 year incidence of target lesion re-intervention was 10.9% after provisional and 8.9% after routine T-stenting (P = 0.64). Conclusions Routine T-stenting with SES did not improve the angiographic outcome of percutaneous coronary intervention of coronary bifurcation lesions as compared with stenting of the main branch followed by kissing-balloon angioplasty and provisional side-branch stenting. PMID:18845665

  14. 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

  15. Global distribution of atmospheric carbon dioxide 2. A review of provisional background observations, 1978--1980

    SciTech Connect

    Fraser, P.J.; Pearman, G.I.; Hyson, P.

    1983-04-20

    An attempt is made to bring together provisional data collected throughout the world to construct a global picture of the background atmospheric carbon dioxide concentration distribution. The uncertainties, calibration and sampling difficulties, and measurement needs are discussed, and it is concluded that in general the accuracy of the provisional data at each sampling location is approx. +- 1 ppmv. Ongoing studies at the main laboratories are likely to significantly improve this accuracy in the near future. The most recent data available (for 1980) indicate annual average northern hemisphere high latitude CO/sub 2/ concentrations 4 to 5 ppmv above those at high latitudes of the southern hemisphere (approx.336 ppmv). The greatest uncertainty in the zonal average concentration exists in the latitude band 10--30 /sup 0/N where surface observations are 2--3 ppmv higher than those measured by continuous analysis at the Mauna Loa Observatory. There is generally good agreement between a model-generated and the observed annual mean global distributions. The seasonality of concentration is small in the southern hemisphere (approx.1--2 ppmv peak to peak) rising to approx.6 ppmv at 20 /sup 0/N and approx.15 ppmv at high latitudes of the northern hemisphere. The total global atmospheric CO/sub 2/ content, averaged through 1980, is estimated to have been 7.15 x 10/sup 14/ kg of carbon with a probable uncertainty of 0.5 to 1.0%.

  16. Reconsidering glass-ionomer cements for direct restorations.

    PubMed

    Pitel, Mark L

    2014-01-01

    Glass-ionomer cements (GICs) have been used in dentistry for a number of applications, primarily as a base or liner under other direct filling materials or indirect restorative materials, for crown buildup/foundation restorations, or as luting cements for indirect restorations. However, GICs have many unique attributes that make them useful for either a full-contour restoration or sandwich/hybrid restorations where they are synergistic with composite resins. This article, which includes two brief case reports, discusses the potential advantages of GIC for some direct applications where composite resin or other materials may not be the most ideal choice. PMID:24571524

  17. 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

  18. Enhanced aesthetics with all ceramics restoration.

    PubMed

    Nayar, Sanjna; Aruna, U; Bhat, Wasim Manzoor

    2015-04-01

    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

  19. 45 CFR 264.71 - What determines the amount of the provisional payment of contingency funds that will be made to a...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... payment of contingency funds that will be made to a State? 264.71 Section 264.71 Public Welfare... Requirements for the Contingency Fund? § 264.71 What determines the amount of the provisional payment of contingency funds that will be made to a State? We will make a provisional payment to a State that meets...

  20. 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

  1. 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.

  2. Refusal to grant provisional General Medical Council registration to U.K. medical graduates.

    PubMed

    David, Timothy J; Ellson, Sarah

    2015-09-01

    In the last five years, 2010-2014, there have been 17 instances when an application for provisional registration by a U.K. medical graduate was refused by the General Medical Council because the Registrar considered that the applicant's fitness to practise was impaired. While this number is small, the fact that this can happen is largely unappreciated by medical students and their teachers, the prevailing false assumption being that passing finals and graduation is the final hurdle before taking up a Foundation Programme post. It is a poorly recognised fact that just because a university fitness to practise committee has concluded that a student is fit to practise there is no guarantee that the General Medical Council will come to the same decision. This paper explains the reasons for these refusals and makes suggestions for students and medical schools. PMID:25882506

  3. 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. PMID:8603212

  4. Developing a provisional standard for clinical supervision in nursing and health visiting: the methodological trail.

    PubMed

    Rafferty, Mic; Jenkins, Emrys; Parke, Sian

    2003-12-01

    The authors outline the process that led to the development of a provisional professional standard for clinical supervision, focusing on design, data collection, and analysis methods. The work was undertaken in an ethos of new paradigm/fifth-generation approaches and used the "manifold of subjective knowing" to gain a holistic understanding of supervisors' experience as represented by experiential, presentational, propositional, and practical knowing. They show how they arrived at the indicators of the standard: Professional Support, Learning, and Accountability. Each of these indicators consists of further elements related to Time, Environment, Relationship (Professional Support), Focus, Knowledge, Interventions (Learning), Organizational Support, Recording, and Competency (Accountability). Findings confirm that clinical supervision practice is complex, and the authors describe proportionally complex methods of analysis. PMID:14658356

  5. Evidence-based provisional clinical classification criteria for autoinflammatory periodic fevers.

    PubMed

    Federici, Silvia; Sormani, Maria Pia; Ozen, Seza; Lachmann, Helen J; Amaryan, Gayane; Woo, Patricia; Koné-Paut, Isabelle; Dewarrat, Natacha; Cantarini, Luca; Insalaco, Antonella; Uziel, Yosef; Rigante, Donato; Quartier, Pierre; Demirkaya, Erkan; Herlin, Troels; Meini, Antonella; Fabio, Giovanna; Kallinich, Tilmann; Martino, Silvana; Butbul, Aviel Yonatan; Olivieri, Alma; Kuemmerle-Deschner, Jasmin; Neven, Benedicte; Simon, Anna; Ozdogan, Huri; Touitou, Isabelle; Frenkel, Joost; Hofer, Michael; Martini, Alberto; Ruperto, Nicolino; Gattorno, Marco

    2015-05-01

    The objective of this work was to develop and validate a set of clinical criteria for the classification of patients affected by periodic fevers. Patients with inherited periodic fevers (familial Mediterranean fever (FMF); mevalonate kinase deficiency (MKD); tumour necrosis factor receptor-associated periodic fever syndrome (TRAPS); cryopyrin-associated periodic syndromes (CAPS)) enrolled in the Eurofever Registry up until March 2013 were evaluated. Patients with periodic fever, aphthosis, pharyngitis and adenitis (PFAPA) syndrome were used as negative controls. For each genetic disease, patients were considered to be 'gold standard' on the basis of the presence of a confirmatory genetic analysis. Clinical criteria were formulated on the basis of univariate and multivariate analysis in an initial group of patients (training set) and validated in an independent set of patients (validation set). A total of 1215 consecutive patients with periodic fevers were identified, and 518 gold standard patients (291 FMF, 74 MKD, 86 TRAPS, 67 CAPS) and 199 patients with PFAPA as disease controls were evaluated. The univariate and multivariate analyses identified a number of clinical variables that correlated independently with each disease, and four provisional classification scores were created. Cut-off values of the classification scores were chosen using receiver operating characteristic curve analysis as those giving the highest sensitivity and specificity. The classification scores were then tested in an independent set of patients (validation set) with an area under the curve of 0.98 for FMF, 0.95 for TRAPS, 0.96 for MKD, and 0.99 for CAPS. In conclusion, evidence-based provisional clinical criteria with high sensitivity and specificity for the clinical classification of patients with inherited periodic fevers have been developed. PMID:25637003

  6. Linaclotide: Promising IBS-C Efficacy in an Era of Provisional Study Endpoints

    PubMed Central

    Sayuk, Gregory S.

    2013-01-01

    Recent disappointing developments in the pharmacotherapy of irritable bowel syndrome (IBS) have not dampened the enthusiasm surrounding linaclotide, a novel guanylate cyclase-C agonist for the management of constipation-predominant IBS (IBS-C). Two recent phase 3 studies reporting on a single, daily dose of linaclotide are presented in this issue of the American Journal of Gastroenterology. Importantly, these studies are the first to examine a provisional Food and Drug Administration (FDA) combined response endpoint for IBS-C, which mandates improvements of both abdominal pain and defecatory symptoms. Potential limitations of this FDA endpoint relate to a lack of inclusion of other potentially important IBS symptoms and an inability to directly compare findings with other recent IBS-C trials. Both studies successfully reached this endpoint in approximately one-third of study subjects, resulting in numbers needed to treat (NNT) of five to eight, to achieve an FDA responder. Individual symptom responses to linaclotide were seen in nearly 50% of participants, and potential explanations for these discrepancies when compared with the FDA endpoint are offered. Adequate relief measures also were assessed and, with NNTs of 3.4–6.8, compared favorably with other contemporary IBS-C studies. Overall, both linaclotide trials found the medication to be safe in terms of serious adverse events, though the secretagogue mechanism of action led to diarrhea in approximately one in five subjects. Together, these studies inspire several other important questions regarding linaclotide, including its role in the management of IBS-C relative to existing treatment options, such as lubiprostone. Greater clinical use of linaclotide will reveal whether the observed responses measured with the FDA provisional endpoint will translate into real-world experiences of improvement in IBS patients. “ In seeking absolute truth we aim at the unattainable and must be content with broken portions

  7. Linaclotide: promising IBS-C efficacy in an era of provisional study endpoints.

    PubMed

    Sayuk, Gregory S

    2012-11-01

    Recent disappointing developments in the pharmacotherapy of irritable bowel syndrome (IBS) have not dampened the enthusiasm surrounding linaclotide, a novel guanylate cyclase-C agonist for the management of constipation-predominant IBS (IBS-C). Two recent phase 3 studies reporting on a single, daily dose of linaclotide are presented in this issue of the American Journal of Gastroenterology. Importantly, these studies are the first to examine a provisional Food and Drug Administration (FDA) combined response endpoint for IBS-C, which mandates improvements of both abdominal pain and defecatory symptoms. Potential limitations of this FDA endpoint relate to a lack of inclusion of other potentially important IBS symptoms and an inability to directly compare findings with other recent IBS-C trials. Both studies successfully reached this endpoint in approximately one-third of study subjects, resulting in numbers needed to treat (NNT) of five to eight, to achieve an FDA responder. Individual symptom responses to linaclotide were seen in nearly 50% of participants, and potential explanations for these discrepancies when compared with the FDA endpoint are offered. Adequate relief measures also were assessed and, with NNTs of 3.4-6.8, compared favorably with other contemporary IBS-C studies. Overall, both linaclotide trials found the medication to be safe in terms of serious adverse events, though the secretagogue mechanism of action led to diarrhea in approximately one in five subjects. Together, these studies inspire several other important questions regarding linaclotide, including its role in the management of IBS-C relative to existing treatment options, such as lubiprostone. Greater clinical use of linaclotide will reveal whether the observed responses measured with the FDA provisional endpoint will translate into real-world experiences of improvement in IBS patients. PMID:23160292

  8. Development of a provisional core set of response measures for clinical trials of systemic sclerosis

    PubMed Central

    Khanna, D; Lovell, D J; Giannini, E; Clements, P J; Merkel, P A; Seibold, J R; Matucci-Cerinic, M; Denton, C P; Mayes, M D; Steen, V D; Varga, J; Furst, D E

    2013-01-01

    Objective To develop a provisional core set of response measures for clinical trials of systemic sclerosis (SSc). Methods The Scleroderma Clinical Trials Consortium (SCTC) conducted a structured, 3-round Delphi exercise to reach consensus on a core set of measures for clinical trials of SSc. Round 1 asked the SCTC investigators to list items in 11 pre-defined domains (skin, musculoskeletal, cardiac, pulmonary, cardio-pulmonary, gastrointestinal, renal, Raynaud phenomenon and digital ulcers, health-related quality of life and function, global health, and biomarkers) for SSc clinical trials. Round 2 asked respondents to rate the importance of the chosen items and was followed by a meeting, during which the Steering Committee discussed the feasibility, reliability, redundancy and validity of the items. Round 3 sought to obtain broader consensus on the core set measures. Members also voted on items that had data on feasibility but lacked data on reliability and validity, but may still be useful research outcome measures for future trials. Results A total of 50 SCTC investigators participated in round 1, providing 212 unique items for the 11 domains. In all, 46 (92%) participants responded in round 2 and rated 177 items. The ratings of 177 items were reviewed by the Steering Committee and 31 items from the 11 domains were judged to be appropriate for inclusion in a 1-year multi-centre clinical trial. In total, 40 SCTC investigators completed round 3 and ranked 30 of 31 items as acceptable for inclusion in the core set. The Steering Committee also proposed 14 items for a research agenda. Conclusion Using a Delphi exercise, we have developed a provisional core set of measures for assessment of disease activity and severity in clinical trials of SSc. PMID:17893248

  9. 14 CFR 121.635 - Dispatch to and from refueling or provisional airports: Domestic and flag operations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... provisional airports: Domestic and flag operations. 121.635 Section 121.635 Aeronautics and Space FEDERAL... COMPENSATION OR HIRE: CERTIFICATION AND OPERATIONS OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL... airports: Domestic and flag operations. No person may dispatch an airplane to or from a refueling...

  10. 14 CFR 121.635 - Dispatch to and from refueling or provisional airports: Domestic and flag operations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... provisional airports: Domestic and flag operations. 121.635 Section 121.635 Aeronautics and Space FEDERAL... COMPENSATION OR HIRE: CERTIFICATION AND OPERATIONS OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL... airports: Domestic and flag operations. No person may dispatch an airplane to or from a refueling...

  11. 14 CFR 121.635 - Dispatch to and from refueling or provisional airports: Domestic and flag operations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... provisional airports: Domestic and flag operations. 121.635 Section 121.635 Aeronautics and Space FEDERAL... COMPENSATION OR HIRE: CERTIFICATION AND OPERATIONS OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL... airports: Domestic and flag operations. No person may dispatch an airplane to or from a refueling...

  12. 14 CFR 121.635 - Dispatch to and from refueling or provisional airports: Domestic and flag operations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... provisional airports: Domestic and flag operations. 121.635 Section 121.635 Aeronautics and Space FEDERAL... COMPENSATION OR HIRE: CERTIFICATION AND OPERATIONS OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL... airports: Domestic and flag operations. No person may dispatch an airplane to or from a refueling...

  13. 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.

  14. 14 CFR 121.635 - Dispatch to and from refueling or provisional airports: Domestic and flag operations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... provisional airports: Domestic and flag operations. 121.635 Section 121.635 Aeronautics and Space FEDERAL... COMPENSATION OR HIRE: CERTIFICATION AND OPERATIONS OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL... airports: Domestic and flag operations. No person may dispatch an airplane to or from a refueling...

  15. 76 FR 68167 - Spin Master, Inc. and Spin Master, Ltd., Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-03

    ... Order AGENCY: 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... that TMG is harmful if swallowed, and that, upon ingestion, it targets the kidneys and central...

  16. 78 FR 8117 - Whalen Furniture Manufacturing, Inc., d/b/a Bayside Furnishings, Provisional Acceptance of a...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-05

    ... Settlement Agreement and Order AGENCY: 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.... Whalen believed that the report it received did not represent a legitimate incident. Whalen was aware...

  17. 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

    ...: 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... defects in its Grasshog XP spool cover in December 2005. It modified the defective spool...

  18. 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

    ...: 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... time, Build-A-Bear denies that it had sufficient information regarding injuries associated with...

  19. 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

  20. Periodontal restorative interrelationships: the isolated restoration.

    PubMed

    Fugazzotto, P A

    1985-06-01

    Only by controlling plaque early and consistently, before periodontal and restorative problems require intervention in the form of a full prosthetic and periodontal reconstruction, the continued maintenance of a full dentition is assured. Plaque control is not merely continued prophylaxes, but a striving for a healthy biologic situation with the placement of every restoration. This is attainable only through ensuring a normal attachment apparatus and establishing that all restorative margins be accessible to plaque control measures. Deep, subgingival restorations are not only difficult to place and finish correctly, but, by providing an environment conducive to microbial plaque retention and proliferation, also lead to inflammatory periodontal destruction and recurrent carious lesions. Early detection, although difficult, is essential to avoid excessive destruction of the tooth and its supporting structures. A deterrent to early detection may be the response of the patient's tissue. Paradoxically, if the patient's periodontal tissues respond in a fibrotic manner to early gingival inflammation, rather than in a dramatic, edematous manner, the situation may appear clinically healthy. Waerhaug discussed "submarginal gingivitis," a situation in which the tissue will appear pink and firm, elicit to exudate or bleeding on probing, and mimic healthy to the casual examiner. When this is coupled with the difficulty inherent in detecting early recurrent carious lesions, resulting from the radiographic superimposition of the existing restoration or the deep subgingival extent of the restoration, the situation becomes all the more demanding of the practitioner's efforts. PMID:3860551

  1. 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.'

  2. 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

  3. Association Between Specific Depression Symptoms and Glycemic Control Among Patients With Comorbid Type 2 Diabetes and Provisional Depression

    PubMed Central

    Czech, Stephanie J.; Orsillo, Susan M.; Pirraglia, Paul A.; English, Thomas M.; Connell, Alexa J.

    2015-01-01

    Objective: To determine whether specific depression symptoms are associated with glycemic control independent of potential demographic and clinical covariates among primary care patients with comorbid type 2 diabetes and provisional threshold or subthreshold depression. Method: We examined a convenience sample of patients diagnosed with type 2 diabetes and provisional threshold or subthreshold depression (N = 82) at 2 family health centers. Cases were identified using a population-based registry of patients diagnosed with type 2 diabetes (ICD-9 codes 250.00 for controlled type 2 diabetes and 250.02 for uncontrolled type 2 diabetes). Data from patients with a primary care provider appointment from the beginning of April 2011 through the end of June 2012 and with at least one 9-item Patient Health Questionnaire (PHQ-9) depression screener and a glycated hemoglobin A1c (HbA1c) laboratory test between 2 weeks before and 10 weeks after PHQ-9 screening were eligible for inclusion. We defined provisional threshold or subthreshold depression using PHQ-9 scoring criteria, which were designed to yield provisional diagnostic information about major depressive disorder based on DSM-5 diagnostic criteria. Results: Patients reporting higher severity of sleep problems on the PHQ-9 had significantly higher HbA1c levels (mean = 8.48, SD = 2.17) compared to patients reporting lower severity or absence of this symptom (mean = 7.19, SD = 1.34, t48.88 = −3.13, P = .003). Problems with sleep contributed unique variance on glycemic control (β = 0.27, P = .02) when controlling for potential clinical and demographic covariates, with those reporting more sleep difficulties having higher HbA1c levels. Conclusions: For patients with type 2 diabetes and provisional threshold or subthreshold depression, it may be prudent to aggressively address sleep problems as a potential mechanism toward improving diabetes control. PMID:26835160

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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

  9. 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

  10. 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…

  11. Restoration of bearings

    NASA Technical Reports Server (NTRS)

    Parker, R. J.; Zaretsky, E. V.; Hanau, H.

    1977-01-01

    Process consisting of grinding raceways to oversize but original quality condition and installing new oversize balls or bearings restores wornout ball and roller bearings to original quality, thereby doubling their operating life. Evaluations reveal process results in restoration of 90% of replaced bearings at less than 50% of new-bearing costs.

  12. 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.

  13. 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.

  14. Biologic Restoration: A Treatment Option for Reconstruction of Anterior Teeth

    PubMed Central

    Khanna, Priyanka; S, Shankar; Chaurasia, Vishwajit Rampratap; Masamatti, Vinaykumar S

    2014-01-01

    Several procedures are advised to manage fractured anterior tooth structure using acrylic resin, composite restoration, ceramic or metal crown with ceramic facing. Biologic restoration is a procedure to restore fractured tooth structure with natural tooth material. In this in vitro case we have made an attempt for aesthetic rehabilitation of maxillary central incisor with similar biologic crown taken form extracted maxillary central incisor. It was observed that biologic restoration is an aesthetic, economical, fast and functional procedure which can be used as an alternative method to restore fractured primary or permanent anteriors. PMID:25584332

  15. 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. PMID:17957457

  16. Development of Native Western North American Triticeae Germplasm in a Restoration Context

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is increasing interest in restoration of native plant communities in the U.S.A. Depending on the practitioner's philosophy of restoration and circumstances of the particular project, there may be needs for plant materials indigenous to the restoration site (primary restoration gene pool) and ...

  17. 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

  18. 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

  19. 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

  20. 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

  1. The Effect of Different Fiber Concentrations on the Surface Roughness of Provisional Crown and Fixed Partial Denture Resin

    PubMed Central

    Zortuk, Mustafa; Kılıc, Kerem; Uzun, Gulay; Ozturk, Ahmet; Kesim, Bulent

    2008-01-01

    Objectives The aim of this study was to investigate surface roughness in provisional crown acrylics, after polishing, reinforced with different concentrations of glass fibers. Methods A total of 48 disk-shaped specimens were prepared using autopolymerizing acrylic resin. These specimens were divided into four groups according to the level of glass fiber added: Group A (no fiber), Group B (0.5%), Group C (1%) and Group D (2%). After polishing the specimens, an average surface roughness (Ra) value was calculated using a profilometer from four randomly selected points on the surface. Results A significant difference was determined among the surface roughness values of provisional crown resins to which different concentrations of fiber had been added (P<.001). Tukey’s test was then used to perform paired comparisons of the data between the different groups, and a significant difference was found between Group A (no fiber) and the other groups, between Group B (0.5%) and Group D (2%) and between Group C (1%) and Group D. On the other hand, there was no significant difference between Group B and Group C. Conclusions The reinforcement of provisional crown and fixed partial denture resin with glass fibers increases surface roughness. PMID:19212545

  2. 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.

  3. Synthesis of poly(alkenoic acid) with L-leucine residue and methacrylate photopolymerizable groups useful in formulating dental restorative materials.

    PubMed

    Buruiana, Tinca; Nechifor, Marioara; Melinte, Violeta; Podasca, Viorica; Buruiana, Emil C

    2014-01-01

    To develop resin-modified glass ionomer materials, we synthesized methacrylate-functionalized acrylic copolymer (PAlk-LeuM) derived from acrylic acid, itaconic acid and N-acryloyl-L-leucine using (N-methacryloyloxyethylcarbamoyl-N'-4-hydroxybutyl) urea as the modifying agent. The spectroscopic (proton/carbon nuclear magnetic resonance, Fourier transform infrared spectroscopy) characteristics, and the gel permeation chromatography/Brookfield viscosity measurements were analysed and compared with those of the non-modified copolymer (PAlk-Leu). The photocurable copolymer (PAlk-LeuM, ~14 mol% methacrylate groups) and its precursor (PAlk-Leu) were incorporated in dental ionomer compositions besides diglycidyl methacrylate of bisphenol A (Bis-GMA) or an analogue of Bis-GMA (Bis-GMA-1), triethylene glycol dimethacrylate and 2-hydroxyethyl methacrylate. The kinetic data obtained by photo-differential scanning calorimetry showed that both the degree of conversion (60.50-75.62%) and the polymerization rate (0.07-0.14 s(-1)) depend mainly on the amount of copolymer (40-50 wt.%), and conversions over 70% were attained in the formulations with 40 wt.% PAlk-LeuM. To formulate light-curable cements, each organic composition was mixed with filler (90 wt.% fluoroaluminosilicate/10 wt.% hydroxyapatite) into a 2.7:1 ratio (powder/liquid ratio). The light-cured specimens exhibited flexural strength (FS), compressive strength (CS) and diametral tensile strength (DTS) varying between 28.08 and 64.79 MPa (FS), 103.68-147.13 MPa (CS) and 16.89-31.87 MPa (DTS). The best values for FS, CS and DTS were found for the materials with the lowest amount of PAlk-LeuM. Other properties such as the surface hardness, water sorption/water solubility, surface morphology and fluorescence caused by adding the fluorescein monomer were also evaluated. PMID:24701975

  4. 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

  5. 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. PMID:21309276

  6. 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

  7. Left ventricular restoration devices.

    PubMed

    Oliveira, Guilherme H; Al-Kindi, Sadeer G; Bezerra, Hiram G; Costa, Marco A

    2014-04-01

    Left ventricular (LV) remodeling results in continuous cardiac chamber enlargement and contractile dysfunction, perpetuating the syndrome of heart failure. With current exhaustion of the neurohormonal medical paradigm, surgical and device-based therapies have been increasingly investigated as a way to restore LV chamber architecture and function. Left ventricular restoration has been attempted with surgical procedures, such as partial left ventriculectomy, surgical ventricular restoration with or without revascularization, and devices, such as the Acorn CorCap, the Paracor HeartNet, and the Myocor Myosplint. Whereas all these techniques require surgical access, with or without cardiopulmonary bypass, a newer ventricular partitioning device (VPD) called Parachute, can be delivered percutaneously through the aortic valve. Designed to achieve LV restoration from within the ventricle, this VPD partitions the LV by isolating aneurysmal from normal myocardium thereby diminishing the functioning cavity. This review aims to critically appraise the above methods, with particular attention to device-based therapies. PMID:24574107

  8. Clinical evaluation of occlusal glass ionomer, resin, and amalgam restorations.

    PubMed

    Smales, R J; Gerke, D C; White, I L

    1990-10-01

    The purpose of the study was to evaluate four materials (a glass ionomer (polyalkenoate) silver cermet, two composite resin restoratives and a high copper content dental amalgam) placed in either conventional Class I cavities or in modified odontotomy-enameloplasty-sealant (OES) fissure preparations. One experienced operator inserted 438 occlusal. Class I restorations in the posterior permanent teeth of 124 patients in a private dental practice. Restorations were assessed for bulk loss of material, surface voids and cracking, restoration margin fractures and staining, and surface staining and roughness, by using colour transparencies taken at baseline and at recalls for up to 3 years. The glass ionomer cermet was the most difficult material to handle and also gave the least satisfactory clinical result. Loss of material and surface voids were common in the cermet restorations with surface cracking or crazing being seen in 11.4 per cent of the restorations, especially in the larger, conventional Class I preparations. One posterior resin was more viscous and difficult to handle than the other resin and exhibited more surface voids. The amalgam alloy was used in Class I preparations only and showed more restoration margin fractures and surface staining than did the other three materials. However, there were no unsatisfactory clinical assessments given for either restoration margin fracture and staining, or surface staining and roughness for any of the materials. Patient acceptance of the modified OES fissure preparation was extremely good. PMID:2127419

  9. Fibronectin provides a conduit for fibroblast transmigration from collagenous stroma into fibrin clot provisional matrix.

    PubMed

    Greiling, D; Clark, R A

    1997-04-01

    After injury, the wound space is filled with a fibrin/fibronectin clot containing growth factors released by platelets and monocytes. In response to these factors, fibroblasts migrate into the fibrin clot and contribute to the formation of granulation tissue. The functional mechanisms allowing fibroblasts to leave the collagenous matrix of normal connective tissue and invade the provisional matrix of the fibrin clot have not been fully defined. To investigate these mechanisms we established a new in vitro model which simulates specific aspects of early wound healing, that is, the migration of fibroblasts from a three-dimensional collagen matrix into a fibrin clot. This transmigration could be induced by physiological concentrations of platelet releasate or platelet-derived growth factor BB (PDGF-BB) in a concentration-dependent manner. At 24 hours irradiated fibroblasts invaded the fibrin gel almost as well as non-irradiated cells, indicating that transmigration was independent of proliferation. Plasminogen and its activators appear to be necessary for invasion of the fibrin clot since protease inhibitors decreased the amount of migration. These serine proteases, however, were not necessary for exit from the collagen gel as fibroblasts migrated out of the collagen gel onto a surface coated with fibrin fibrils even in the presence of inhibitors. Removal of fibronectin (FN) from either the collagen gel or the fibrin gel markedly decreased the number of migrating cells, suggesting that FN provides a conduit for transmigration. Cell movement in the in vitro model was inhibited by RGD peptide, and by monoclonal antibodies against the subunits of the alpha5 beta1 and alpha v beta3 integrin receptor. Thus, the functional requirements for fibroblast transmigration from collagen-rich to fibrin-rich matrices, such as occurs in early wound healing, have been partially defined using an in vitro paradigm of this important biologic process. PMID:9133673

  10. Technical framework for groundwater restoration

    SciTech Connect

    Not Available

    1991-04-01

    This document provides the technical framework for groundwater restoration under Phase II of the Uranium Mill Tailings Remedial Action (UMTRA) Project. A preliminary management plan for Phase II has been set forth in a companion document titled ``Preplanning Guidance Document for Groundwater Restoration``. General principles of site characterization for groundwater restoration, restoration methods, and treatment are discussed in this document to provide an overview of standard technical approaches to groundwater restoration.

  11. 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

  12. 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

  13. 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…

  14. 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.

  15. Earthquake funding restored

    NASA Astrophysics Data System (ADS)

    Bush, Susan

    Funding levels for the U.S. Geological Survey's part of the National Earthquake Hazards Reduction Program for FY92 have been restored by the House and a Senate subcommittee. The president's budget request for FY92 was only $37.3 million, lower than the $54.5 million authorized by Congress for FY91. Earlier this year the House agreed on restoring $10 million to the program. Some AGU members have been trying to see the full $17.2 million difference restored. It is reported that the Senate will agree to give $15 million to the program.When Congress reconvenes in September the full Senate will vote on the Department of Interior and Related Agencies appropriations bill (HR2686). After that, the bill will go to a joint conference committee, where differences between the House and Senate will be resolved before the bill is passed along to the president.

  16. 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

  17. Materialism.

    PubMed

    Melnyk, Andrew

    2012-05-01

    Materialism is nearly universally assumed by cognitive scientists. Intuitively, materialism says that a person's mental states are nothing over and above his or her material states, while dualism denies this. Philosophers have introduced concepts (e.g., realization and supervenience) to assist in formulating the theses of materialism and dualism with more precision, and distinguished among importantly different versions of each view (e.g., eliminative materialism, substance dualism, and emergentism). They have also clarified the logic of arguments that use empirical findings to support materialism. Finally, they have devised various objections to materialism, objections that therefore serve also as arguments for dualism. These objections typically center around two features of mental states that materialism has had trouble in accommodating. The first feature is intentionality, the property of representing, or being about, objects, properties, and states of affairs external to the mental states. The second feature is phenomenal consciousness, the property possessed by many mental states of there being something it is like for the subject of the mental state to be in that mental state. WIREs Cogn Sci 2012, 3:281-292. doi: 10.1002/wcs.1174 For further resources related to this article, please visit the WIREs website. PMID:26301463

  18. 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

  19. Inevitability of Balance Restoration

    PubMed Central

    2010-01-01

    Prolonged imbalance between input and output of any element in a living organism is incompatible with life. The duration of imbalance varies, but eventually balance is achieved. This rule applies to any quantifiable element in a compartment of finite capacity. Transient discrepancies occur regularly, but given sufficient time, balance is always achieved, because permanent imbalance is impossible, and the mechanism for eventual restoration of balance is foolproof. The kidney is a central player for balance restoration of fluid and electrolytes, but the smartness of the kidney is not the reason for perfect balance. The kidney merely accelerates the process. The most crucial element of the control system is that discrepancy between intake and output inevitably leads to a change in total content of the element in the system, and uncorrected balance has a cumulative effect on the overall content of the element. In a living organism, the speed of restoration of balance depends on the permissible duration of imbalance without death or severe disability. The three main factors that influence the speed of balance restoration are: magnitude of flux, basal store, and capacity for additional storage. For most electrolytes, total capacity is such that a substantial discrepancy is not possible for more than a week or two. Most control mechanisms correct abnormality partially. The infinite gain control mechanism is unique in that abnormality is completely corrected upon completion of compensation. PMID:21468193

  20. BALTIMORE STREAM RESTORATION PROJECT

    EPA Science Inventory

    26 Feb 2003



    Approach - We will employ a 4-tiered research approach to investigate restoration effects on hydrology and stream water quality: 1) monitoring ground water and surface water, 2) quantifying denitrification activity, 3) measuring carbon supply and rete...

  1. Restoration of face images

    NASA Astrophysics Data System (ADS)

    Srinivasan, Aparna

    2012-01-01

    Restoration techniques are applied to degraded face samples. The techniques considered are those of Wiener Filtering, Lucy Richardson deconvolution, Blind deconvolution and Constrained least squares filtering (CLSF). Images degraded by low blur, high blur and low blur with noise are experimented with and the results are expounded.

  2. Restoration of face images

    NASA Astrophysics Data System (ADS)

    Srinivasan, Aparna

    2011-12-01

    Restoration techniques are applied to degraded face samples. The techniques considered are those of Wiener Filtering, Lucy Richardson deconvolution, Blind deconvolution and Constrained least squares filtering (CLSF). Images degraded by low blur, high blur and low blur with noise are experimented with and the results are expounded.

  3. ECOLOGICAL PROTECTION AND RESTORATION

    EPA Science Inventory

    To carry out this mission, GLNPO established its Ecological Protection and Restoration Team (the E Team), consisting of a staff plus extended team members from EPA Regions 2, 3, and 5, other federal and state agencies, and non-governmental organizations. GLNPO expect...

  4. 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…

  5. 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.

  6. 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

  7. Immediate occlusal loading in edentulous jaws, CT-guided surgery and fixed provisional prosthesis: a maxillary arch clinical report.

    PubMed

    Drago, Carl; del Castillo, Robert; Peterson, Thomas

    2011-04-01

    Immediate occlusal loading (IOL) in edentulous jaws has been reported in numerous publications with implant cumulative survival rates consistent with conventional, unloaded healing protocols. Computed Tomography (CT)-guided surgery has more recently been developed and accepted as an additional treatment modality for maxillary and mandibular implant placement, with or without IOL. Reports as to the accuracy of planned versus actual implant placement in CT-guided surgeries have indicated that CT-guided surgery is not 100% accurate; standard deviations have been reported with values between 1 and 2 mm in terms of actual versus planned placement. The purpose of this article is to review the clinical parameters associated with IOL, and CT-guided surgery in edentulous jaws; and to present a clinical case illustrating the clinical and laboratory phases of treatment. The illustrated treatment was accomplished with an IOL protocol and includes fabrication and placement of a laboratory-processed provisional maxillary prosthesis. This particular protocol had slightly increased costs relative to conventional implant placement; however, the clinicians and patient benefited from improved accuracy of the provisional prostheses and decreased chairtime for the clinical procedures. The benefits and limitations of this treatment protocol are also discussed. PMID:21070431

  8. The Effects of Side Branch Predilation During Provisional Stenting of Coronary Bifurcation Lesions: A Double-Blind Randomized Controlled Trial

    PubMed Central

    Peighambari, Mohammadmehdi; Sanati, Hamidreza; Hadjikarimi, Majid; Zahedmehr, Ali; Shakerian, Farshad; Firouzi, Ata; Kiani, Reza; Sadeghipour, Parham; Kzaemi Asl, Siamak

    2016-01-01

    Background: There is a paucity of data regarding the role of side branch (SB) predilation during the provisional stenting of bifurcation lesions. Objectives: The present study aimed to assess the effects of SB predilation on the outcomes of true bifurcation interventions. Patients and Methods: Sixty patients with true bifurcation lesions according to the Medina classification were included in the study and randomly assigned to receive SB predilation before stenting the main branch (n = 30) or no predilation as the control group (n = 30). Results: There was a trend toward the higher occurrence of dissection in the predilated ostial lesions of the SB compared to the non-predilated group (16.7% vs. 0, P = 0.07). Performance of the SB predilation was not associated with improved flow of the SB or fewer degrees of ostial stenosis after stenting the main branch, the need to rewire, rewiring time, or the rate of use of the final kissing balloon dilation and double stents procedures. Conclusions: Routine predilation of the SB in provisional stenting of true bifurcation lesions seems to be ineffective and might be associated with some undesirable consequences. Still, there are some complex ostial lesions of the SB which could benefit from predilation. PMID:26949691

  9. Life analysis of restored and refurbished bearings

    NASA Technical Reports Server (NTRS)

    Coy, J. J.; Zaretsky, E. V.; Cowgill, G. R.

    1977-01-01

    An analysis of the potential life of refurbished and restored bearings was performed. The sensitivity of 10-percent life and mean-time-between-failure to the effects of cumulative fatigue damage and the amount of stressed volume removed in the restoration process were examined. A modified Lundberg-Palmgren theory was used to predict that the expected 10-percent life of a restored bearing, which is dependent on the previous service time and the volume of material removed from the race surfaces, can be between 74 and 100 percent of the new bearing life. Using renewal theory, it is found that the mean time between failure ranged from 90 to 100 percent of that for a new bearing.

  10. Current status of zirconia restoration.

    PubMed

    Miyazaki, Takashi; Nakamura, Takashi; Matsumura, Hideo; Ban, Seiji; Kobayashi, Taira

    2013-10-01

    currently one of the most reliable bonding systems for zirconia. Adhesive treatments could be applied to luting the restorations and fabricating hybrid-structured FDPs. Full-contour zirconia FDPs caused concern about the wear of antagonist enamel, because the hardness of Y-TZP was over double that of porcelain. However, this review demonstrates that highly polished zirconia yielded lower antagonist wear compared with porcelains. Polishing of zirconia is possible, but glazing is not recommended for the surface finish of zirconia. Clinical data since 2010 are included in this review. The zirconia frameworks rarely got damaged in many cases and complications often occurred in the veneering ceramic materials. Further clinical studies with larger sample sizes and longer follow-up periods are required to investigate the possible influencing factors of technical failures. PMID:24140561

  11. Adhesive restorations in the posterior area with subgingival cervical margins: new classification and differentiated treatment approach.

    PubMed

    Veneziani, Marco

    2010-01-01

    The aim of this article is to analyze some of the issues related to the adhesive restoration of teeth with deep cervical and/or subgingival margins in the posterior area. Three different problems tend to occur during restoration: loss of dental substance, detection of subgingival cervical margins, and dentin sealing of the cervical margins. These conditions, together with the presence of medium/large-sized cavities associated with cuspal involvement and absence of cervical enamel, are indications for indirect adhesive restorations. Subgingival margins are associated with biological and technical problems such as difficulty in isolating the working field with a dental dam, adhesion procedures, impression taking, and final positioning of the restoration itself. A new classification is suggested based on two clinical parameters: 1) a technicaloperative parameter (possibility of correct isolation through the dental dam) and 2) a biological parameter (depending on the biologic width). Three different clinical situations and three different therapeutic approaches are identified (1st, 2nd, and 3rd, respectively): coronal relocation of the margin, surgical exposure of the margin, and clinical crown lengthening. The latter is associated with three further operative sequences: immediate, early, or delayed impression taking. The different therapeutic options are described and illustrated by several clinical cases. The surgical-restorative approach, whereby surgery is strictly associated with buildup, onlay preparation, and impression taking is particularly interesting. The restoration is cemented after only 1 week. This approach makes it possible to speed up the therapy by eliminating the intermediate phases associated with positioning the provisional restorations, and with fast and efficient healing of the soft marginal tissue. PMID:20305873

  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. PMID:26332738

  13. Current opinions concerning the restoration of endodontically treated teeth: basic principles

    PubMed Central

    VȦrlan, C; VȦrlan, V; Bodnar, D; Suciu, I

    2009-01-01

    The goal of this general article is to present a survey of the current knowledge about the clinical approach of restoring endodontically treated teeth. The best way to restore teeth after root canal treatment has long been and still is a controversial subject of debate to this day. The clinical approach of restoring endodontically treated teeth needs taking into consideration several issues: aims of coronal restoration, criteria for establishing the various modalities of coronal restoration, clinical solutions of restoring teeth after endodontic treatment, guidelines regarding restorative materials and techniques, possibilities and limits of restoration using direct adhesive materials and techniques. The aims of coronal restoration of endodontically treated teeth are generally considered to be the following ones: to prevent recontamination of the root canal system and / or periapical space, to replace missing hard dental tissues and to restore coronal morphology and functions, to provide the necessary strength for the restoration/tooth complex in order to withstand functional stress and prevent crown and/or root fracture. The criteria for establishing the modalities of coronal restoration for endodontically treated teeth are: amount and quality of remaining hard dental tissues, topography and coronal morphology of the tooth, functional occlusal forces that the restoration/tooth complex has to withstand, restoring requirements in order to include the treated tooth in a comprehensive oral rehabilitation treatment plan, esthetic requirements. PMID:20108535

  14. Achieving highly esthetic anterior restorations with ideal assessment, communication, and technique.

    PubMed

    Finlay, Scott; Rego, Nelson

    2014-01-01

    Although all cases should be approached comprehensively, restoring a limited segment in the esthetic zone presents challenges particularly related to microesthetics. Microesthetics are those criteria related to the subtle intricacies of shade, textures, translucencies, and surface effects that make teeth look like teeth. These are the criteria that aid dentists in fooling the eye and allowing restorations to blend invisibly into the smile. Completing a comprehensive assessment of a patient ensures that the restorative foundation will remain biologically and structurally predictable, durable, and above all, esthetically pleasing. Starting esthetic treatment without first doing a comprehensive assessment will result in a compromised result. Within the criteria of microesthetics, the utilization of a common nomenclature and quantitative means of communication between the restorative dentist and the laboratory ceramist are at the core of success. The use of prototypes during the provisionalization phase and progressive techniques in digital photography are invaluable tools. Along with traditional techniques in acquiring proper shade selection, the use of cross-polarization filters has been proven to be an effective way to eliminate spectral artifacts typically found in flash photography. Additionally, the use of a color-corrected master die system provides the ceramist a method to calibrate shades on the lab bench by capturing images--via the cross-polarization filters--that are similar to what is observed clinically. PMID:25369384

  15. Digital restoration of multichannel images

    NASA Technical Reports Server (NTRS)

    Galatsanos, Nikolas P.; Chin, Roland T.

    1989-01-01

    The Wiener solution of a multichannel restoration scheme is presented. Using matrix diagonalization and block-Toeplitz to block-circulant approximation, the inversion of the multichannel, linear space-invariant imaging system becomes feasible by utilizing a fast iterative matrix inversion procedure. The restoration uses both the within-channel (spatial) and between-channel (spectral) correlation; hence, the restored result is a better estimate than that produced by independent channel restoration. Simulations are also presented.

  16. Prairie Restoration for Wisconsin Schools.

    ERIC Educational Resources Information Center

    Murray, Molly Fifield; Greenler, Robin McC.

    This packet is composed of several resources for teachers interested in prairie ecology and restoration. "A Guide to Restoration from Site Analysis to Management" focuses on the Prairie/Oak Savanna communities of Wisconsin and takes teachers through the planning and design process for a restoration project on school grounds including site…

  17. Adaptive wiener image restoration kernel

    DOEpatents

    Yuan, Ding

    2007-06-05

    A method and device for restoration of electro-optical image data using an adaptive Wiener filter begins with constructing imaging system Optical Transfer Function, and the Fourier Transformations of the noise and the image. A spatial representation of the imaged object is restored by spatial convolution of the image using a Wiener restoration kernel.

  18. Engineering approaches to ecosystem restoration

    SciTech Connect

    Hayes, D.F.

    1998-07-01

    This proceedings CD ROM contains 127 papers on developing and evaluating engineering approaches to wetlands and river restoration. The latest engineering developments are discussed, providing valuable insights to successful approaches for river restoration, wetlands restoration, watershed management, and constructed wetlands for stormwater and wastewater treatment. Potential solutions to a wide variety of ecosystem concerns in urban, suburban, and coastal environments are presented.

  19. Restoration of longitudinal images.

    PubMed

    Hu, Y; Frieden, B R

    1988-01-15

    In this paper, a method of restoring longitudinal images is developed. By using the transfer function for longitudinal objects, and inverse filtering, a longitudinal image may be restored. The Fourier theory and sampling theorems for transverse images cannot be used directly in the longitudinal case. A modification and reasonable approximation are introduced. We have numerically established a necessary relationship between just-resolved longitudinal separation (after inverse filtering), noise level, and the taking conditions of object distance and lens diameter. An empirical formula is also found to well-fit the computed results. This formula may be of use for designing optical systems which are to image longitudinal details, such as in robotics or microscopy. PMID:20523607

  20. Relativistic Linear Restoring Force

    ERIC Educational Resources Information Center

    Clark, D.; Franklin, J.; Mann, N.

    2012-01-01

    We consider two different forms for a relativistic version of a linear restoring force. The pair comes from taking Hooke's law to be the force appearing on the right-hand side of the relativistic expressions: d"p"/d"t" or d"p"/d["tau"]. Either formulation recovers Hooke's law in the non-relativistic limit. In addition to these two forces, we…

  1. Restoration of Elbow Flexion.

    PubMed

    Loeffler, Bryan J; Lewis, Daniel R

    2016-08-01

    Active elbow flexion is required to position the hand in space, and loss of this function is debilitating. Nerve transfers or nerve grafts to restore elbow flexion may be options when the target muscle is viable, but in delayed reconstruction when the biceps and brachialis are atrophied or damaged, muscle transfer options should be considered. Muscle transfer options are discussed with attention to the advantages and disadvantages of each transfer option. PMID:27387075

  2. Effect of Industry Sponsorship on Dental Restorative Trials.

    PubMed

    Schwendicke, F; Tu, Y-K; Blunck, U; Paris, S; Göstemeyer, G

    2016-01-01

    Industry sponsorship was found to potentially introduce bias into clinical trials. We assessed the effects of industry sponsorship on the design, comparator choice, and findings of randomized controlled trials on dental restorative materials. A systematic review was performed via MEDLINE, CENTRAL, and EMBASE. Randomized trials on dental restorative and adhesive materials published 2005 to 2015 were included. The design of sponsored and nonsponsored trials was compared statistically (risk of bias, treatment indication, setting, transferability, sample size). Comparator choice and network geometry of sponsored and nonsponsored trials were assessed via network analysis. Material performance rankings in different trial types were estimated via Bayesian network meta-analysis. Overall, 114 studies were included (15,321 restorations in 5,232 patients). We found 21 and 41 (18% and 36%) trials being clearly or possibly industry sponsored, respectively. Trial design of sponsored and nonsponsored trials did not significantly differ for most assessed items. Sponsored trials evaluated restorations of load-bearing cavities significantly more often than nonsponsored trials, had longer follow-up periods, and showed significantly increased risk of detection bias. Regardless of sponsorship status, comparisons were mainly performed within material classes. The proportion of trials comparing against gold standard restorative or adhesive materials did not differ between trial types. If ranked for performance according to the need to re-treat (best: least re-treatments), most material combinations were ranked similarly in sponsored and nonsponsored trials. The effect of industry sponsorship on dental restorative trials seems limited. PMID:26442947

  3. Reasons for Placement of Restorations on Previously Unrestored Tooth Surfaces by Dental PBRN Dentists

    PubMed Central

    Nascimento, Marcelle M.; Gordan, Valeria V.; Qvist, Vibeke; Litaker, Mark S.; Rindal, D. Brad; Williams, O.D.; Fellows, Jeffrey L.; Ritchie, Lloyd K.; Mjör, Ivar A.; McClelland, Jocelyn; Gilbert, Gregg H.

    2010-01-01

    Objective To identify and quantify the reasons for placing restorations on unrestored permanent tooth surfaces and the dental materials used by Dental Practice-Based Research Network (DPBRN; www.DentalPBRN.org) dentists. Methods A total of 229 DPBRN practitioner-investigators collected data on 9,890 consecutive restorations from 5,810 patients. Information included: (1) reasons for restoring; (2) tooth and surfaces restored; and (3) restorative materials employed. Results Primary caries (85%) and non-carious defects (15%), which included abrasion/ abfraction/ erosion lesions and tooth fracture, were the main reasons for placement of restorations. Restorations due to caries were frequently placed on occlusal surfaces (49%), followed by distal, mesial, buccal/facial, lingual/palatal, and incisal surfaces. Amalgam was used for 46% of the molar and 45% of the premolar restorations. Directly placed resin-based composite (RBC) was used for 48% of the molar, 49% of the premolar, and 92% of the anterior restorations. Conclusion Dental caries on occlusal and proximal surfaces of molar teeth are the main reasons for placing restorations on previously unrestored tooth surfaces by DPBRN practitioner-investigators. RBC is the material most commonly used for occlusal and anterior restorations. Amalgam remains the material of choice to restore proximal caries in posterior teeth, although there are significant differences by DPBRN region. PMID:20354094

  4. Longevity of posterior dental restorations and reasons for failure.

    PubMed

    Kopperud, Simen E; Tveit, Anne Bjørg; Gaarden, Torunn; Sandvik, Leiv; Espelid, Ivar

    2012-12-01

    Tooth-coloured restorative materials are being used increasingly more often in Class II preparations in permanent teeth. Using a practice-based study design, we aimed to assess the survival time of Class II restorations and to identify factors relevant to their longevity. Class II restorations (n = 4,030), consisting of resin composites (81.5%), compomers (12.7%), amalgams (4.6%), and glass-ionomer cement restorations (1.2%), were placed in 1,873 patients with a median age of 15 yr. In total, 92.7% of restorations were placed due to primary caries and 5.8% were replacements. After an average follow-up period of 4.6 yr, 61.6% of the restorations were successful, 11.2% had failed, and 27.2% were not available for evaluation (owing to patient drop-out). The mean annual failure rate was 2.9% for resin-composite restorations and 1.6% for amalgams. For resin-composite restorations, secondary caries was the most common reason for replacement (73.9%), followed by loss (8.0%), fracture (5.3%), and marginal defects (2.4%). Multilevel Cox-regression analyses identified young age of the patient, high previous caries experience, deep cavities, and saucer-shaped preparation technique as predisposing to shorter longevity of resin-composite restorations. One brand of resin composite had a shorter survival time than the others. PMID:23167471

  5. [Restoration of hemi-arcades with amalgam].

    PubMed

    Vermeersch, A G

    1975-01-01

    As a rule should the half-mouth restorations in the frame of oral rehabilitation be done with gold inlays, overlays or full crowns. It is nevertheless possible to consider such restorations with amalgam and, providing that certain principles and technics and respected, such quadrant restorations could be valuable as well on the periodontal point of view as on the occlusal one. Regarding the periodontal point of view, it is now generally accepted that de restorations of the proximal aspects of the teeth have not to extend under the gingival margin. If this creates a risk for caries recurrences, still questionable, it eliminates the unavoidable periodontal lesions. Regarding the occlusal point of view, it is on the one hand difficult to build up a perfect occlusal restoration with a material which, on the moment the filling is completed acquires only a insufficient fraction of its final resistance. On the other hand it seems impossible to raise the occlusion in one or more teeth for the very same reason. The solution to this problem comprises a dubbel aspect. One has first of all to rebuild to the desired occlusal level the cavities of the whole quadrant with a temporary but resistant material wich allows at once a carefulness mastication. Polycarboxylate cement is suitable for this purpose. This temporary material is then replaced tooth after tooth in one or more sittings with amalgam. The second aspect of the solution consists in the use of amalgam wich acquires faster a sufficent resistance, allowing an ajustment of a perfect occlusion without the danger of fracturing it. Following the first estimates it seems that amalgam made of spherical particules and dispersed phase type alloys could meet with this requirements and bring an acceptable solution to our problem. PMID:1065913

  6. Filling cavities or restoring teeth?

    PubMed

    Versluis, Antheunis; Versluis-Tantbirojn, Daranee

    2011-01-01

    Teeth seldom fracture under normal functional loading. This indicates that the natural tooth design is optimized for the distribution of regular masticatory forces by means of its properties and structure. When a tooth is restored with an intracoronal restoration, however, the incidence of tooth fracture increases. Since remaining tissues do not change, the restorative actions apparently alter the original stress distributions. In this study, the effect of different restoration types (unbonded amalgam and bonded composite restorations) were compared with the original stress conditions of the intact tooth, using finite element analysis. It was shown that an unbonded amalgam restoration did not restore the original stress conditions but led to much higher stresses in the buccal and lingual enamel and to higher tensile stresses in the cavity floor. The unbonded amalgam thus filled the cavity but did not restore the tooth. In contrast, a bonded composite restoration restored the original stress pattern in the tooth if there was no polymerization shrinkage. Polymerization shrinkage causes residual tensile stresses in the dentin around the cavity and in the buccal and lingual enamel. Residual tensile stresses in the buccal and lingual enamel are momentary compensated by compressive stress components during occlusal loading. It was concluded that bonding and elimination of residual stresses are prerequisites for restoring the original tooth integrity. PMID:21748978

  7. Image restoration, uncertainty, and information.

    PubMed

    Yu, F T

    1969-01-01

    Some of the physical interpretations about image restoration are discussed. From the theory of information the unrealizability of an inverse filter can be explained by degradation of information, which is due to distortion on the recorded image. The image restoration is a time and space problem, which can be recognized from the theory of relativity (the problem of image restoration is related to Heisenberg's uncertainty principle in quantum mechanics). A detailed discussion of the relationship between information and energy is given. Two general results may be stated: (1) the restoration of the image from the distorted signal is possible only if it satisfies the detectability condition. However, the restored image, at the best, can only approach to the maximum allowable time criterion. (2) The restoration of an image by superimposing the distorted signal (due to smearing) is a physically unrealizable method. However, this restoration procedure may be achieved by the expenditure of an infinite amount of energy. PMID:20072171

  8. The decision to repair or replace a defective restoration is affected by who placed the original restoration: findings from the National Dental PBRN

    PubMed Central

    Gordan, Valeria V; Riley, Joseph; Geraldeli, Saulo; Williams, O. Dale; Spoto, Joseph C; Gilbert, Gregg H

    2014-01-01

    Objectives To evaluate how restoration characteristics are associated with the decision to repair or replace an existing restoration. The following hypotheses were studied: Dentists who placed the original restoration are more likely to repair instead of replace restorations (H1) that are in molar teeth; (H2) that are in the upper arch; (H3) that have amalgam restorative material; (H4) if a fracture is not the primary reason for the defect; and (H5) when the restoration comprises more than one surface. Methods This cross-sectional study used a consecutive patient/restoration recruitment design. 194 dentists members of a dental practice-based research network recorded data on restorations in permanent teeth that needed repair or replacement. Results For 6,623 of the 8,770 defective restorations in 6,643 patients, the treatment was provided by the dentist who had not placed the original restoration (75%). The 2-way interaction revealed that dentists who had placed the original restoration often chose to repair when the defective restoration was in a molar, relative to premolar or anterior teeth (OR = 2.2, p < .001); and chose to replace when the restoration had amalgam (OR = 0.5, p < .001), and when it was a fracture compared to another reason (OR = 0.8, p = 001). Conclusion Most dentists are not conservative when they revisit a restoration that they originally placed regardless of type of failure, number of surfaces or material used. However, dentists who had placed the original restoration were significantly more likely to repair it when the defective restoration was in a molar tooth. PMID:25223822

  9. Glass-ionomer Cements in Restorative Dentistry: A Critical Appraisal.

    PubMed

    Almuhaiza, Mohammed

    2016-01-01

    Glass-ionomer cements (GICs) are mainstream restorative materials that are bioactive and have a wide range of uses, such as lining, bonding, sealing, luting or restoring a tooth. Although the major characteristics of GICs for the wider applications in dentistry are adhesion to tooth structure, fluoride releasing capacity and tooth-colored restorations, the sensitivity to moisture, inherent opacity, long-term wear and strength are not as adequate as desired. They have undergone remarkable changes in their composition, such as the addition of metallic ions or resin components to their composition, which contributed to improve their physical properties and diversified their use as a restorative material of great clinical applicability. The light-cured polymer reinforced materials appear to have substantial benefits, while retaining the advantages of fluoride release and adhesion. Further research should be directed towards improving the properties, such as strength and esthetics without altering its inherent qualities, such as adhesion and fluoride releasing capabilities. PMID:27340169

  10. Influence of different transitional restorations on the fracture resistance of premolar teeth.

    PubMed

    Qualtrough, A J; Cawte, S G; Wilson, N H

    2001-01-01

    Controversy exists over the most favorable material and type of restoration to be used to transitionally restore teeth destined to be crowned. This in vitro study uses fracture resistance testing to compare eight different transitional restorations in maxillary premolars. Ninety sound maxillary premolars were randomly selected and allocated to nine groups, each comprising 10 teeth. One group remained unrestored and was used as the control. Teeth in the remaining groups were prepared to a standard cavity form using: a copy milling process removing the palatal cusp. Restorations were placed using amalgam with dentin pins and cavity varnish; amalgam with an amalgam bonding agent; resin composite with dentin pins and a dentin bonding agent; resin composite with a dentin bonding agent only; resin-modified glass ionomer with dentin pins; resin-modified glass ionomer cement alone and cermet with dentin pins and cermet alone. Each restored tooth was then subjected to axial loading via a bar contacting the buccal and restored palatal cusps until failure of the restored tooth occurred. The mean load-to-fracture values were statistically compared and the modes of failure recorded. It was found that the choice of restorative material and type of restoration had little effect on the fracture resistance of the restored tooth with the exception of those teeth restored with reinforced glass ionomer cement alone, which exhibited a significantly lower resistance to fracture than the other restored teeth. However, the choice of restorative material/technique did influence the mode of failure. Failure in teeth restored with resin-modified glass ionomer cement alone produced the least damage to the remaining tooth tissue when failure occurred. Consequently, this material may offer the most favorable range of properties for the transitional restoration of extensively broken-down maxillary premolar teeth destined to be crowned. Furthermore, the findings of this study fail to support the

  11. Prediction and diagnosis of clinical outcomes affecting restoration margins.

    PubMed

    Dennison, J B; Sarrett, D C

    2012-04-01

    The longevity of dental restorations is largely dependent on the continuity at the interface between the restorative material and adjacent tooth structure (the restoration margin). Clinical decisions on restoration repair or replacement are usually based upon the weakest point along that margin interface. Physical properties of a restorative material, such as polymerisation shrinkage, water sorption, solubility, elastic modulus and shear strength, all have an effect on stress distribution and can significantly affect margin integrity. This review will focus on two aspects of margin deterioration in the oral environment: the in vitro testing of margin seal using emersion techniques to simulate the oral environment and to predict clinical margin failure and the relationship between clinically observable microleakage and secondary caries. The many variables associated with in vitro testing of marginal leakage and the interpretation of the data are presented in detail. The most recent studies of marginal leakage mirror earlier methodology and lack validity and reliability. The lack of standardised testing procedures makes it impossible to compare studies or to predict the clinical performance of adhesive materials. Continual repeated in vitro studies contribute little to the science in this area. Clinical evidence is cited to refute earlier conclusions that clinical microleakage (penetrating margin discoloration) leads to caries development and is an indication for restoration replacement. Margin defects, without visible evidence of soft dentin on the wall or base of the defect, should be monitored, repaired or resealed, in lieu of total restoration replacement. PMID:22066463

  12. THE PEDIATRIC RHEUMATOLOGY INTERNATIONAL TRIALS ORGANIZATION PROVISIONAL CRITERIA FOR THE EVALUATION OF RESPONSE TO THERAPY IN JUVENILE DERMATOMYOSITIS

    PubMed Central

    Ruperto, Nicolino; Pistorio, Angela; Ravelli, Angelo; Rider, Lisa G.; Pilkington, Clarissa; Oliveira, Sheila; Wulffraat, Nico; Espada, Graciela; Garay, Stella; Cuttica, Ruben; Hofer, Michael; Quartier, Pierre; Melo-Gomes, Jose; Reed, Ann M.; Wierzbowska, Malgorzata; Feldman, Brian M.; Harjacek, Miroslav; Huppertz, Hans-Iko; Nielsen, Susan; Flato, Berit; Lahdenne, Pekka; Michels, Harmut; Murray, Kevin J.; Punaro, Lynn; Rennebohm, Robert; Russo, Ricardo; Balogh, Zsolt; Rooney, Madeleine; Pachman, Lauren M.; Wallace, Carol; Hashkes, Philip; Lovell, Daniel J.; Giannini, Edward H.; Martini, Alberto

    2010-01-01

    Objective To develop a provisional definition for the evaluation of response to therapy in juvenile dermatomyositis (JDM) based on the PRINTO JDM core set of variables. Methods Thirty-seven experienced pediatric rheumatologists from 27 countries, achieved consensus on 128 difficult patient profiles as clinically improved or not improved using a stepwise approach (patients rating, statistical analysis, definition selection). Using the physicians’ consensus ratings as the “gold-standard measure”, chi-square, sensitivity, specificity, false positive and negative rate, area under the ROC, and kappa agreement for candidate definitions of improvement were calculated. Definitions with kappa >0.8 were multiplied with the face validity score to select the top definitions. Results The top definition of improvement was: at least 20% improvement from baseline in 3/6 core set variables with no more than 1 of the remaining worsening by more than 30%, which cannot be muscle strength. The second highest scoring definition was at least 20% improvement from baseline in 3/6 core set variables with no more than 2 of the remaining worsening by more than 25%, which cannot be muscle strength which is definition P1 selected by the IMACS group. The third is similar to the second with the maximum amount of worsening set to 30%. This indicates convergent validity of the process. Conclusion we proposes a provisional data driven definition of improvement that reflects well the consensus rating of experienced clinicians, which incorporates clinically meaningful change in core set variables in a composite endpoint for the evaluation of global response to therapy in JDM. PMID:20583105

  13. The feline oral microbiome: a provisional 16S rRNA gene based taxonomy with full-length reference sequences.

    PubMed

    Dewhirst, Floyd E; Klein, Erin A; Bennett, Marie-Louise; Croft, Julie M; Harris, Stephen J; Marshall-Jones, Zoe V

    2015-02-25

    The human oral microbiome is known to play a significant role in human health and disease. While less well studied, the feline oral microbiome is thought to play a similarly important role. To determine roles oral bacteria play in health and disease, one first has to be able to accurately identify bacterial species present. 16S rRNA gene sequence information is widely used for molecular identification of bacteria and is also useful for establishing the taxonomy of novel species. The objective of this research was to obtain full 16S rRNA gene reference sequences for feline oral bacteria, place the sequences in species-level phylotypes, and create a curated 16S rRNA based taxonomy for common feline oral bacteria. Clone libraries were produced using "universal" and phylum-selective PCR primers and DNA from pooled subgingival plaque from healthy and periodontally diseased cats. Bacteria in subgingival samples were also cultivated to obtain isolates. Full-length 16S rDNA sequences were determined for clones and isolates that represent 171 feline oral taxa. A provisional curated taxonomy was developed based on the position of each taxon in 16S rRNA phylogenetic trees. The feline oral microbiome curated taxonomy and 16S rRNA gene reference set will allow investigators to refer to precisely defined bacterial taxa. A provisional name such as "Propionibacterium sp. feline oral taxon FOT-327" is an anchor to which clone, strain or GenBank names or accession numbers can point. Future next-generation-sequencing studies of feline oral bacteria will be able to map reads to taxonomically curated full-length 16S rRNA gene sequences. PMID:25523504

  14. Enrollment in Postsecondary Institutions, Fall 2011; Financial Statistics, Fiscal Year 2011; and Graduation Rates, Selected Cohorts, 2003-2008: First Look (Provisional Data). NCES 2012-174rev

    ERIC Educational Resources Information Center

    Knapp, Laura G.; Kelly-Reid, Janice E.; Ginder, Scott A.

    2012-01-01

    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…

  15. Immediate placement and provisionalization of maxillary anterior single implant with guided bone regeneration, connective tissue graft, and coronally positioned flap procedures.

    PubMed

    Waki, Tomonori; Kan, Joseph Y K

    2016-01-01

    Immediate implant placement and provisionalization in the esthetic zone have been documented with success. The benefit of immediate implant placement and provisionalization is the preservation of papillary mucosa. However, in cases with osseous defects presenting on the facial bony plate, immediate implant placement procedures have resulted in facial gingival recession. Subepithelial connective tissue grafts for immediate implant placement and provisionalization procedures have been reported with a good esthetic outcome. Biotype conversion around implants with subepithelial connective tissue grafts have been advocated, and the resulting tissues appear to be more resistant to recession. The dimensions of peri-implant mucosa in a thick biotype were significantly greater than in a thin biotype. Connective tissue graft with coronally positioned flap procedures on natural teeth has also been documented with success. This article describes a technique combining immediate implant placement, provisionalization, guided bone regeneration (GBR), connective tissue graft, and a coronally positioned flap in order to achieve more stable peri-implant tissue in facial osseous defect situations. PMID:27092345

  16. Documentation to the NCES Common Core of Data Local Education Agency Universe Survey: School Year 2011-12. Provisional Version 1a. NCES 2014-035

    ERIC Educational Resources Information Center

    Keaton, Patrick

    2014-01-01

    This documentation is for the provisional version 1a file of the National Center for Education Statistics' (NCES) Common Core of Data (CCD) Local Education Agency (LEA) Universe Survey for SY 2011-12. It contains a brief description of the data collection, along with information required to understand and access the data file. The CCD is a…

  17. Documentation to the NCES Common Core of Data Public Elementary/Secondary School Universe Survey: School Year 2011-12. Provisional Version 1a. NCES 2014-100

    ERIC Educational Resources Information Center

    Keaton, Patrick

    2013-01-01

    The documentation for this provisional version 1a file of the National Center for Education Statistics' (NCES) Common Core of Data (CCD) Public Elementary/Secondary School Universe Survey for SY 2011-12, contains a brief description of the data collection, along with information required to understand and access the data file. The SY 2011-12…

  18. Enrollment and Employees in Postsecondary Institutions, Fall 2014; and Financial Statistics and Academic Libraries, Fiscal Year 2014. First Look (Provisional Data). NCES 2016-005

    ERIC Educational Resources Information Center

    Ginder, Scott A.; Kelly-Reid, Janice E.; Mann, Farrah B.

    2015-01-01

    This First Look presents findings from the provisional data of the Integrated Postsecondary Data System (IPEDS) Spring 2015 data collection, which included four survey components: (1) Enrollment at postsecondary institutions during fall 2014; (2) Finance, for the 2014 fiscal year; (3) Human Resources at postsecondary institutions during fall 2014;…

  19. AIDS Knowledge and Attitudes, Provisional Data from the National Health Interview Survey: United States, August 1987. Advance Data from Vital and Health Statistics. No. 146.

    ERIC Educational Resources Information Center

    Dawson, Deborah A.; And Others

    This document presents provisional data for all Acquired Immune Deficiency Syndrome (AIDS) questionnaire items from the National Health Interview Survey (NHIS) for August 1987. It notes that the AIDS questionnaire was designed to provide baseline estimates of public knowledge and attitudes about AIDS transmission, the prevention of AIDS virus…

  20. Employees in Postsecondary Institutions, Fall 2011 and Student Financial Aid, Academic Year 2010-11: First Look (Provisional Data). NCES 2012-156rev

    ERIC Educational Resources Information Center

    Knapp, Laura G.; Kelly-Reid, Janice E.; Ginder, Scott A.

    2012-01-01

    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…

  1. Graduation Rates for Selected Cohorts, 2005-10; and Student Financial Aid in Postsecondary Institutions, Academic Year 2012-13. First Look (Provisional Data). NCES 2014-105

    ERIC Educational Resources Information Center

    Ginder, Scott A.; Kelly-Reid, Janice E.; Mann, Farrah B.

    2014-01-01

    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…

  2. Complications in hair restoration.

    PubMed

    Lam, Samuel M

    2013-11-01

    Hair restoration requires a high level of specialized skill on the part of both the surgeon and the assistant team. Recipient-site problems can manifest from either surgeon or assistant error. The surgeon can create an unnatural hairline due to lack of knowledge of natural hair-loss patterns or badly executed recipient sites. He must also be cognizant of how hairs naturally are angled on the scalp to re-create a pattern that appears natural when making recipient sites. Assistants can also greatly contribute to the success or failure of surgery in their task of graft dissection and graft placement. PMID:24200385

  3. Robotic hair restoration.

    PubMed

    Rose, Paul T; Nusbaum, Bernard

    2014-01-01

    The latest innovation to hair restoration surgery has been the introduction of a robotic system for harvesting grafts. This system uses the follicular unit extraction/follicular isolation technique method for harvesting follicular units, which is particularly well suited to the abilities of a robotic technology. The ARTAS system analyzes images of the donor area and then a dual-chamber needle and blunt dissecting punch are used to harvest the follicular units. The robotic technology is now being used in various locations around the world. This article discusses the use of the robotic system, its capabilities, and the advantages and disadvantages of the system. PMID:24267426

  4. Percutaneous left ventricular restoration.

    PubMed

    Ige, Mobolaji; Al-Kindi, Sadeer G; Attizzani, Guilherme; Costa, Marco; Oliveira, Guilherme H

    2015-04-01

    The ventricular partitioning device known as Parachute is the first and only percutaneously implantable device aimed at restoration of normal left ventricular geometry in humans. Since its conception, this technology has undergone extensive animal and human testing, with proved feasibility and safety, and is currently being studied in a pivotal randomized clinical trial. This article discusses ventricular remodeling and therapies attempted in the past, details the components of the ventricular partitioning device, describes the implanting technique, and reviews the most current experience of this device in humans. PMID:25834974

  5. Complex fixed implant-supported restoration in a site compromised by periodontitis: a case report.

    PubMed

    Happe, Arndt; Kunz, Andreas

    2016-01-01

    Periodontal disease presents a big challenge for clinicians placing dental implants. Besides the implant treatment, additional surgical procedures such as grafting or sinus floor elevation are often necessary to achieve a satisfactory result. Patient compliance is also important for achieving long-term treatment success. In the case presented here, digital planning and computer-aided surgery facilitated placement of the implants and fabrication of the prosthetic superstructures. The patient then wore INTERNAT IONAL metal-based provisional fixed partial dentures (FPDs) for about a year, while her compliance and oral hygiene were evaluated. During this period, the occlusal relations remained stable and the good condition of the hard and soft tissue was maintained. In the maxilla, the final restoration incorporated custom zirconia abutments and a zirconia framework fabricated using CAD/CAM technology. Titanium abutments and a cast non-precious metal framework were fabricated for the mandible. PMID:27092346

  6. Languages of South Asia. A Survey of Materials for the Study of the Uncommonly Taught Languages.

    ERIC Educational Resources Information Center

    Johnson, Dora E.; And Others

    This is an annotated bibliography of basic tools of access for the study of the uncommonly taught languages of South Asia. It is one of eight fascicles which constitute a revision of "A Provisional Survey of Materials for the Study of the Neglected Languages" (CAL 1969). The emphasis is on materials for the adult learner whose native language is…

  7. Reparative dentistry or restorative dentistry?

    PubMed

    Small, Bruce W

    2008-01-01

    The real definition of restorative dentistry is found in the heart and hands of each individual restorative dentist. His or her training, continuing dental education, mentors, needs (financial and emotional), and style of practice all help to develop a philosophy of dental practice that affects daily restorative decisions. Depending on the factors described above, the decision to repair a tooth or change the environment and restore the tooth to a different shape, size, or color also may change. In recent years, patients' esthetic desires have become more of a factor than they were in previous decades. There are no exact written-tn-stone definitions of restorative dentistry, since the answers are operator-dependent and can vary. This column is meant to be food for thought and perhaps inspire discussion when dentists assemble for meetings or study clubs with the goal of delivering longer-lasting dentistry through a restorative dental practice. PMID:18348367

  8. Long-term deterioration of composite resin and amalgam restorations.

    PubMed

    Smales, R J

    1991-01-01

    Previous long-term longitudinal studies of two different methods of placing an auto-cured conventional anterior composite resin, and of a low- and a high-copper amalgam alloy, had shown similar restoration survivals despite the different resin treatment methods used or the types of amalgam alloy placed. Therefore, the aim of the present study was to assess several clinical factors or characteristics of these restorations that were believed to affect the survival of the restorative materials. The 950 composite resin and the 1042 amalgam restorations examined were placed by many operators in numerous patients attending a dental hospital. The composite resin restorations were placed using unetched- and etched-enamel-bonding treatment methods, and the amalgam restorations were polished after insertion. Clinical ratings supplemented by color transparencies were used for the assessment of four factors for the resin, and four factors for the amalgam restoration. Significant deterioration differences were found for several of the clinical factors assessed for both the two different composite resin treatment methods, and for the two different amalgam alloys, which were not directly related to the restoration survivals. PMID:1840079

  9. Materials

    NASA Technical Reports Server (NTRS)

    Glaessgen, Edward H.; Schoeppner, Gregory A.

    2006-01-01

    NASA Langley Research Center has successfully developed an electron beam freeform fabrication (EBF3) process, a rapid metal deposition process that works efficiently with a variety of weldable alloys. The EBF3 process can be used to build a complex, unitized part in a layer-additive fashion, although the more immediate payoff is for use as a manufacturing process for adding details to components fabricated from simplified castings and forgings or plate products. The EBF3 process produces structural metallic parts with strengths comparable to that of wrought product forms and has been demonstrated on aluminum, titanium, and nickel-based alloys to date. The EBF3 process introduces metal wire feedstock into a molten pool that is created and sustained using a focused electron beam in a vacuum environment. Operation in a vacuum ensures a clean process environment and eliminates the need for a consumable shield gas. Advanced metal manufacturing methods such as EBF3 are being explored for fabrication and repair of aerospace structures, offering potential for improvements in cost, weight, and performance to enhance mission success for aircraft, launch vehicles, and spacecraft. Near-term applications of the EBF3 process are most likely to be implemented for cost reduction and lead time reduction through addition of details onto simplified preforms (casting or forging). This is particularly attractive for components with protruding details that would require a significantly large volume of material to be machined away from an oversized forging, offering significant reductions to the buy-to-fly ratio. Future far-term applications promise improved structural efficiency through reduced weight and improved performance by exploiting the layer-additive nature of the EBF3 process to fabricate tailored unitized structures with functionally graded microstructures and compositions.

  10. Occlusal glass ionomer cermet, resin sandwich and amalgam restorations: a 2-year clinical study.

    PubMed

    Lidums, A; Wilkie, R; Smales, R

    1993-08-01

    This study compared the clinical behavior of a glass ionomer silver cermet (Ketac-Silver), a posterior resin composite (Visio-Molar) used with the "sandwich" technique, and a high-copper amalgam (Dispersalloy) for restoring conventional Class I occlusal cavity preparations. Two dentists placed 116 restorations in the posterior permanent teeth of 35 adults treated at a dental hospital. Restorations were assessed at 6-month intervals over 2 years for bulk loss of material and occlusal wear, surface voids, roughness and cracking, surface and marginal staining, and marginal fracture. Losses of material and surface voids were obvious with the cermet material, with surface crazing or cracking being present in 33% of the restorations. The cermet cannot be recommended as a long-term permanent restorative material if the restorations are likely to be subjected to heavy occlusal stresses and abrasive wear. PMID:7803005

  11. The metal-free approach to restorative treatment planning.

    PubMed

    Cortellini, Davide; Valenti, Marco; Canale, Angelo

    2006-01-01

    Considerable developments in the area of metal-free restorations--in response to increasing esthetic demands from patients--are offering the clinician and dental technician new therapeutic paths to follow when performing restorative treatments. Effective and reliable high-strength ceramic systems, suitable for anterior and posterior sites, may allow the achievement of predictable esthetics and function. Along with the evident indications for the treatment of anterior compromised elements, these types of restorations may be used in a wider variety of clinical cases, including complex prosthetic rehabilitations. Appropriate usage of different materials according to the specific clinical situation is mandatory for long-lasting, functional, and esthetic results. Therefore, a thorough application of metal-free restorations may be considered a "metal-free approach", which includes a specific formulation of treatment planning. In this article, the different materials, selection criteria, clinical indications, and benefits are evaluated, with a particular regard for treatment planning. PMID:19655489

  12. CAD/CAM ceramic restorations in the operatory and laboratory.

    PubMed

    Fasbinder, Dennis J

    2003-08-01

    Computer assisted design/computer assisted machining (CAD/CAM) technology has received considerable clinical and research interest from modern dental practices as a means of delivering all-ceramic restorations. The CEREC, System offers CAD/CAM dental technology designed for clinical use by dentists, as well as a separate system designed for dental laboratory technicians. The CEREC 3 system is indicated for dental operatory applications, and the CEREC inLab, system is indicated for dental laboratory applications. Although both systems rely on similar CAD/CAM technology, several significant differences exist in the processing techniques involved, restorative materials used, and types of restoration provided. PMID:14692164

  13. Microveneering technique for esthetic enhancement of monolithic zirconia restorations.

    PubMed

    Kurbad, Andreas

    2016-01-01

    The importance of monolithic ceramic restorations is growing, given the safe and cost-effective options for fabrication of such dental crowns and fixed dental prostheses. The optical characteristics of traditional zirconia do not suffice for this purpose. Improved restorative materials that can achieve satisfactory results in posterior restorations have been proposed to solve the problem. In the anterior region, however, even "esthetic" zirconia ceramic is unable to attain results comparable to those of glass-ceramic. Microveneering is a simple, reliable, and timesaving solution. Minimal reduction and veneering can significantly improve the results. A characteristic case is presented here. PMID:27274564

  14. A Simplified Method for the Restoration of Severely Decayed Primary Incisors

    PubMed Central

    Talebi, Maryam; Parisay, Iman; Khorakian, Fatemeh; Nik, Elham

    2015-01-01

    Objectives: Caries and dental trauma are common reasons for primary anterior teeth restorations in children. This non-control clinical trial was designed to evaluate crown restorations reinforced with a sectioned file post for the restoration of severely damaged primary maxillary incisors. Materials and Methods: Thirty-eight primary maxillary incisors of 12 children (3–5 years old) with early childhood caries (ECC) received composite restorations with a custom made post. The restorations were evaluated using the modified United State Public Health Service (USPHS) criteria. The results were statistically analyzed by descriptive –analytical tests. Results: In this trial, the quality of marginal adaptation decreased after three and 12 months intervals. Recurrent carious lesions were observed during intervals. In terms of restoration retention, only one patient lost both the post and the restoration at the 12-month follow up. Conclusion: The sectioned file post technique showed good retention and aesthetics for restoring severely damaged primary maxillary anterior teeth. PMID:26622269

  15. Immediate restoration of single implants placed immediately after implant removal. A case report.

    PubMed

    Covani, Ugo; Marconcini, Simone; Santini, Stefano; Cornelini, Roberto; Barone, Antonio

    2010-12-01

    The purpose of this case report is to describe the treatment of implants placed in fresh extraction sockets and immediately restored in cases of failure. A healthy 58-year-old nonsmoking man was referred for an implant that had lost osseointegration because of infection. The prosthesis showed slight mobility. It was therefore decided to remove the implant and replace it with a new one immediately. Since the patient refused to wear a provisional removable prosthesis, the possibility of applying an immediate loading protocol was discussed. The failed implant was removed carefully and the residual extraction socket was thoroughly debrided. Subsequently, the new implant was placed with a sterile surgical technique, as described by the manufacturer. The inserted implant had a titanium plasma-sprayed surface. Immediately following implant placement and with the patient still under local anesthesia, the initial restorative treatment began. The patient was placed on a strict follow-up regimen until soft tissue healing was complete. Subsequent follow-up examinations were performed after 12 months. At each recall, the patient underwent a thorough clinical and radiographic evaluation. The healing period proceeded smoothly. At the end of the follow-up period, the implant was asymptomatic, immobile, and osseointegrated. No peri-implant bony defects were observed on probing. The results of the present case report seem to suggest that implants placed in fresh extraction sockets and restored immediately might provide a valid treatment option for the treatment of failed implants. PMID:20967310

  16. Interactions between cavity preparation and restoration events and their effects on pulp vitality.

    PubMed

    Wisithphrom, Kessiri; Murray, Peter E; About, Imad; Windsor, L Jack

    2006-12-01

    The purpose of this study was to investigate the precise effect and rank the importance of cavity preparation and restoration variables on human pulp vitality. Fifty-three Class V unexposed cavities were prepared and restored with calcium hydroxide/amalgam, resin-modified glass ionomer, zinc oxide-eugenol, resin composite, or zinc polycarboxylate materials. Pulp vitality was reduced by the remaining dentin thickness of the cavity preparations, whereas the other variables, including the type of restorative material, had little effect. Restorative materials cause minimal pulp damage in isolation; it is more important to minimize the removal of intact dentin to maintain the vitality of teeth. PMID:17243333

  17. Provisional Approaches to Goals for School Mathematics; Cambridge Conference on School Mathematics Feasibility Study No. 37.

    ERIC Educational Resources Information Center

    Cambridge Conference on School Mathematics, Newton, MA.

    These materials were written with the aim of reflecting the thinking of Cambridge Conference on School Mathematics (CCSM) regarding the goals and objectives for school mathematics K-6. In view of the experiences of other curriculum groups and of the general discussions since 1963, the present report initiates the next step in evolving the "Goals".…

  18. Provisional Teachers Failing the Mississippi Teacher Assessment Instruments for Certification: An Evaluation for 1991-92.

    ERIC Educational Resources Information Center

    Amos, Neil; Cheeseman, Robert H.

    The Mississippi Teacher Assessment Instruments (MTAIs) contain 16 teaching competencies (14 competencies measured by 3 separate instruments of the MTAI, and 2 performance standards assessed by the local district). The Teaching Plans and Materials MTAI guides assessment of beginning teachers' competence in planning instruction, selecting…

  19. Penetrating School Strata Through Career Education (Grades 9-12). Provisional Curriculum Guide.

    ERIC Educational Resources Information Center

    Bristol Public Schools, CT.

    The career education curriculum guide for grades 9-12 contains activities that can be integrated with existing curricula. Career education activities are organized under the headings of goals, objectives, materials, procedures, anticipated results, and evaluation within the subject areas of art, business, consumer education, distributive…

  20. Restoring medical professionalism.

    PubMed

    Bernat, James L

    2012-08-21

    The essence of medical professionalism is placing dedication to the welfare of patients above physicians' personal or proprietary interests. Medicine has become deprofessionalized as a consequence of socioeconomic factors leading to increasing commercialization and perverse financial incentives converting it into a business, the presence of unmanaged conflicts of interest, challenges to medical authority by insurance companies and the consumerism movement, and by gradual changes in the attitudes of physicians. Organized medicine has responded by making explicit its standards of professionalism and its dedication to preserving them. Medical educators have studied the means to develop professional attitudes and behaviors among medical students and residents. Modeling the characteristics of professional behavior by virtuous physicians remains the most effective method to instill professional behaviors in trainees. Restoring professionalism may be abetted by changes in physicians' financial incentives through innovative models of health care delivery, by physicians reducing their conflicts of interest, and by medical societies rejecting a guild identity. PMID:22915177