INFLUENCE OF DIE SPACER APPLICATION ON MARGINAL ADAPTATION OF INDIRECT TEMPORARY CROWNS FABRICATED USING STONE AND SILICONE MODEL MATERIALS

2017 ◽  
Vol 63 (2) ◽  
pp. 1891-1901
Author(s):  
Lomaya Ghanem
Keyword(s):  
Marginal Adaptation ◽  
Silicone Model ◽  
Die Spacer

scholarly journals Marginal Adaptation and Micropermeability of Class II Cavities Restored with Three Different Types of Resin Composites—A Comparative Ten-Month In Vitro Study

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1660
Author(s):  
Sevda Mihailova Yantcheva
Keyword(s):  
Methylene Blue ◽  
In Vitro Study ◽  
Sem Analysis ◽  
Marginal Adaptation ◽  
Resin Composites ◽  
Polymerization Shrinkage ◽  
Gingival Margin ◽  
Different Types ◽  
Ageing Period

The development of composite materials is subject to the desire to overcome polymerization shrinkage and generated polymerization stress. An indicator characterizing the properties of restorative materials, with specific importance for preventing secondary caries, is the integrity and durability of marginal sealing. It is a reflection of the effects of polymerization shrinkage and generated stress. The present study aimed to evaluate and correlate marginal integrity and micropermeability in second-class cavities restored with three different types of composites, representing different strategies to reduce polymerization shrinkage and stress: nanocomposite, silorane, and bulk-fill composite after a ten-month ageing period. Thirty standardized class ΙΙ cavities were prepared on extracted human molars. Gingival margins were 1 mm apical to the cementoenamel junction. Cavities were randomly divided into three groups, based on the composites used: FiltekUltimate-nanocomposite; Filtek Silorane LS-silorane; SonicFill-bulk-fill composite. All specimens were subjected to thermal cycles after that, dipped in saline for 10-mounds. After ageing, samples were immersed in a 2% methylene blue. Thus prepared, they were covered directly with gold and analyzed on SEM for assessment of marginal seal. When the SEM analysis was completed, the teeth were included into epoxy blocks and cut longitudinally on three slices for each cavity. An assessment of microleakage on stereomicroscope followed. Results were statistically analyzed. For marginal seal evaluation: F.Ultimate and F.Silorane differ statistically with more excellent results than SonicFill for marginal adaptation to the gingival margin, located entirely in the dentin. For microleakage evaluation: F.Ultimate and F.Silorane differ statistically with less microleakage than SonicFill. Based on the results obtained: a strong correlation is found between excellent results for marginal adaptation to the marginal gingival ridge and micropermeability at the direction to the axial wall. We observe a more significant influence of time at the gingival margin of the cavities. There is a significant increase in the presence of marginal fissures (p = 0.001). A significant impact of time (p < 0.000) and of the material (p < 0.000) was found in the analysis of the microleakage.

scholarly journals Clinical Evaluation of Flowable Composite Materials in Permanent Molars Small Class I Restorations: 3-Year Double Blind Clinical Study

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4283
Author(s):  
Walter Dukić ◽  
Mia Majić ◽  
Natalija Prica ◽  
Ivan Oreški
Keyword(s):  
Clinical Study ◽  
Composite Materials ◽  
Retention Rate ◽  
Statistical Significance ◽  
United States Public Health ◽  
Class I ◽  
Marginal Adaptation ◽  
Small Class ◽  
Flowable Composite ◽  
Permanent Molars

This study evaluated the 3-year clinical performance of four different flowable composite materials used in Small Class I restorations in permanent molars. This double-blinded, clinical study analyzed 229 Small Class I restorations/103 children at baseline, 12, 24, and 36 months with modified United States Public Health Services (USPHS) criteria. The tested flowable materials were Voco Grandio Flow + Voco Solobond M, Vivadent Tetric EvoFlow + Vivadent Excite, Dentsply X-Flow + Dentsply Prime&Bond NT, and 3M ESPE Filtek Supreme XT Flow + 3M ESPE Scotchbond Universal. The retention and marginal adaptation rates were highest for Grandio Flow and X Flow materials after 36 months, resulting in the highest score of clinical acceptability at 95.3% and 97.6%, respectively. The Tetric EvoFlow and Filtek Supreme XT Flow had the same retention rate after 36 months at 88.1%. Statistical significance was found in Grandio flow material in postoperative sensitivity criteria (p = 0.021). Tetric EvoFlow showed statistical differences in retention (p = 0.01), color match (p = 0.004), and marginal adaptation (p = 0.042). Filtek Supreme showed statistical differences in retention (p = 0.01) and marginal adaptation (p < 0.001). The flowable composite materials showed excellent clinical efficacy after 36 months of their clinical usage. There was no difference among the tested flowable composite materials quality in Small Class I restorations over time.

scholarly journals Sensitivity analysis of FDA´s benchmark nozzle regarding in vitro imperfections - Do we need asymmetric CFD benchmarks?

2020 ◽  
Vol 6 (3) ◽  
pp. 78-81
Author(s):  
Michael Stiehm ◽  
Christoph Brandt-Wunderlich ◽  
Stefan Siewert ◽  
Klaus-Peter Schmitz ◽  
Niels Grabow ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Flow Field ◽  
In Silico ◽  
Nozzle Geometry ◽  
Geometrical Imperfection ◽  
Custom Made ◽  
Inlet Conditions ◽  
Silicone Model ◽  
Bench Testing

AbstractModern technologies and methods such as computer simulation, so-called in silico methods, foster the development of medical devices. For accelerating the uptake of computer simulations and to increase credibility and reliability the U.S. Food and Drug Administration organized an inter-laboratory round robin study of a generic nozzle geometry. In preparation of own bench testing experiment using Particle Image Velocimetry, a custom made silicone nozzle was manufactured. By using in silico computational fluid dynamics method the influence of in vitro imperfections, such as inflow variations and geometrical deviations, on the flow field were evaluated. Based on literature the throat Reynolds number was varied Rethroat = 500 ± 50. It could be shown that the flow field errors resulted from variations of inlet conditions can be largely eliminated by normalizing if the Reynolds number is known. Furthermore, a symmetric imperfection of the silicone model within manufacturing tolerance does not affect the flow as much as an asymmetric failure such as an unintended curvature of the nozzle. In brief, we can conclude that geometrical imperfection of the reference experiment should be considered accordingly to in silico modelling. The question arises, if an asymmetric benchmark for biofluid analysis needs to be established. An eccentric nozzle benchmark could be a suitable case and will be further investigated.

scholarly journals Radiological Evaluation of Stainless Steel Crowns Placed on Permanent Teeth in Patients Treated under General Anaesthesia

2021 ◽  
Vol 18 (5) ◽  
pp. 2509
Author(s):  
Marie-Laure Munoz-Sanchez ◽  
Natacha Linas ◽  
Nicolas Decerle ◽  
Valérie Collado ◽  
Denise Faulks ◽  
...  
Keyword(s):  
Stainless Steel ◽  
General Anaesthesia ◽  
Alveolar Bone ◽  
Dental Treatment ◽  
Glass Ionomer Cement ◽  
Permanent Teeth ◽  
Marginal Adaptation ◽  
Permanent Molars ◽  
A Minor ◽  
Ionomer Cement

Evidence-based evaluations of dental treatment are needed to support the development of special care dentistry services. This retrospective study was designed to collect and analyse X-ray images of permanent teeth restored with stainless steel crowns (SSC) in patients treated under general anaesthesia. Between 2013 and 2019, 360 permanent molars were crowned with SSCs in 198 adult patients. One calibrated investigator used an original validated tool to evaluate four radiographic criteria for molars restored with SSCs: i) marginal adaptation; ii) interdental proximal contact; iii) the presence of glass ionomer cement overflow; and iv) the loss of alveolar bone. Overall, no defect or a minor defect was reported for the majority of SSCs for the criteria “Marginal adaptation” (62.5%, n = 320), “Proximal contact” (82.2%, n = 236) and “Cement overflow” (95.8%, n = 337). Alveolar bone resorption was reported in 8.3% of cases, n = 14, after a mean period of 8.9 ± 14.3 months. It was shown that the restoration of permanent teeth using SSCs placed under general anaesthesia presents a low risk of periodontal morbidity in the medium term when assessed radiographically.

scholarly journals Accuracy and Reliability of Methods to Measure Marginal Adaptation of Crowns and FDPs: A Literature Review

2013 ◽  
Vol 22 (5) ◽  
pp. 419-428 ◽  
Author(s):  
Noor A. Nawafleh ◽  
Florian Mack ◽  
Jane Evans ◽  
John Mackay ◽  
Muhanad M. Hatamleh
Keyword(s):  
Literature Review ◽  
Marginal Adaptation

scholarly journals Vertical and Horizontal Misfit Analysis of 3-unit FDP Fabricated with Different Techniques and CAD/CAM Systems

2018 ◽  
Vol 29 (4) ◽  
pp. 342-346
Author(s):  
Eduardo Piza Pellizzer1 ◽  
Caroline Cantieri de Mello ◽  
Jéssica Marcela de Luna Gomes ◽  
Joel Ferreira Santiago Júnior ◽  
Cleidiel Aparecido Araújo Lemos ◽  
...  
Keyword(s):  
Reference Model ◽  
Optical Microscope ◽  
The Other ◽  
Marginal Adaptation ◽  
Nicr Alloy ◽  
Partial Denture ◽  
Optical Scanning ◽  
Fixed Partial Denture ◽  
Cad Cam ◽  
Cam Systems

Abstract The aim of this is was evaluate the vertical and horizontal marginal adaptation of 3-unit fixed partial denture frameworks fabricated using different techniques and CAD/CAM systems. A total of 40 framework specimens were fabricated and divided into four groups as follows: lost-wax casting (G1); lost-wax casting with welding (G2); extraoral optical scanning of models (3S/DWOS) (G3); intraoral optical scanning (Cerec Bluecam/Sirona) (G4). A reference model was used to simulate a fixed partial denture with three elements (with a central pontic). The frameworks of G1 and G2 were cast in nickel-chromium (NiCr) alloy, whereas those of G3 and G4 were milled in zirconia. In all groups, vertical and horizontal marginal adaptation (over-contour and under-contour) was evaluated using a three-dimensional optical microscope (Quick Scope, Mitutoyo). The results showed higher vertical marginal misfit in G1 than in the other groups (p<0.001). Regarding horizontal marginal misfit, higher over-contour values occurred in G3 than in the other groups (p<0.001). G3 did not show under-contour at all, whereas the other groups did not differ from each other in this regard (p>0.05). Within the limitations of this study, it can be concluded that lost-wax casting with welding is a viable alternative to the use of CAD/CAM systems to fabricate frameworks of three-unit FPDs, since the techniques yielded similar vertical misfit values. Extra-oral CAD/CAM systems showed the highest horizontal misfit (over-contour) compared to other groups.

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