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Al-Qahtani SD, Al-Senani GM. Green and sustainable smart wooden system integrated with cellulose nanowhiskers-supported polyvinyl alcohol and anthocyanin biomolecules to monitor food freshness. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 318:124497. [PMID: 38795527 DOI: 10.1016/j.saa.2024.124497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2024] [Revised: 05/08/2024] [Accepted: 05/19/2024] [Indexed: 05/28/2024]
Abstract
Smart packaging materials have been used to protect human health from environmental hazards by sending real-time colorimetric signals for changes in the food packaging environment. However, the colorimetric material sensors use synthetic sensor dyes, which are toxic, expensive, non-biodegradable, and difficult to prepare. Herein, a simple strategy is presented for the development of an environmentally-friendly halochromic wood able to change color upon exposure to spoilage of food. A combination of anthocyanin (Ac)/aluminum (Al) mordant (Ac/Al) nanoparticles and cellulose nanowhiskers (CNW)-reinforced polyvinyl alcohol (PVA) was infiltrated into a delignified wood to produce a translucent wood with halochromic properties. CNW were employed as reinforcement agent to improve the mechanical performance of PVA. Additionally, CNW function as a dispersing agent to prevent agglomeration of Ac/Al nanoparticles. The diameters of CNW are in the range of 12-19 nm, whereas Ac/Al particles showed diameters of 9-22 nm. The smart wood changed color from purplish to colorless when exposed to food spoilage. A hypsochromic change from 539 nm to 370 nm was shown by the anthocyanin receptor when the spoilage level of food increased. This could be attributed to the pH-driven molecular switching of anthocyanin, leading to charge delocalization.
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Affiliation(s)
- Salhah D Al-Qahtani
- Department of Chemistry, College of Science, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia
| | - Ghadah M Al-Senani
- Department of Chemistry, College of Science, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia.
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Kouri V, Moldovani D, Papazoglou E. Accuracy of Direct Composite Veneers via Injectable Resin Composite and Silicone Matrices in Comparison to Diagnostic Wax-Up. J Funct Biomater 2023; 14:32. [PMID: 36662079 PMCID: PMC9864032 DOI: 10.3390/jfb14010032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 01/01/2023] [Accepted: 01/03/2023] [Indexed: 01/08/2023] Open
Abstract
Purpose: To evaluate the discrepancy between the diagnostic wax-up and the resulting direct veneers using different matrices. Materials and method: A total of 48 identical misaligned models, 12 wax-up models and one ‘every other tooth’ wax-up model were 3D printed. Group 1: Transparent silicone matrices with holes for the injection of the flowable composite. Group 2: The same procedure as group 1, but the first three teeth were restored using the matrix constructed from the ‘every other tooth’ wax-up model. Group 3: Transparent silicone matrices cut for each tooth and preheated resin composite. Group 4: The same procedure as group 3, but the loaded matrix was placed first in the clear plastic tray, which was used for the matrix’s fabrication. Group 5: Wax-up models (control group). Scans from the veneers were superimposed with the scans from the wax-up and compared using the Patient Monitoring software. Measurements were made at the incisal, middle and cervical third. Kruskal-Wallis test and Dunn post-hoc test (p < 0.05) were used to analyze the results. Results: No statistically significant differences were found between groups 1 and 2 and the control. Group 3 was different from the control in the incisal and middle third, and group 4 was different in the cervical third. Conclusions: (1) Use of one or two matrices and the injection of flowable composite were accurate techniques. (2) Use of a matrix for each tooth combined with a pre-heated composite was the most inaccurate technique, but the use of the clear tray in combination with the matrix improved the accuracy.
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Affiliation(s)
- Vasiliki Kouri
- Operative Dentistry, National and Kapodistrian University, 11527 Athens, Greece
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3
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Pivesso BP, Cavalheiro ETG, Palhares TN, Neumann MG, Schmitt CC. 3D printed dental protheses using TPO-initiated photopolymerization. Effect of the photoinitiator concentration and the use of a UV-blocker. POLYM-PLAST TECH MAT 2022. [DOI: 10.1080/25740881.2022.2121217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Bruno P Pivesso
- Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos SP, Brazil
| | - Eder T. G. Cavalheiro
- Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos SP, Brazil
| | - Thiago N. Palhares
- Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos SP, Brazil
| | - Miguel G. Neumann
- Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos SP, Brazil
| | - Carla C. Schmitt
- Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos SP, Brazil
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Comparison of the Hardness of Novel Experimental Vinyl Poly Siloxane (VPS) Impression Materials with Commercially Available Ones. BIOMED RESEARCH INTERNATIONAL 2022; 2022:1703869. [PMID: 35187157 PMCID: PMC8849984 DOI: 10.1155/2022/1703869] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 10/14/2021] [Accepted: 01/26/2022] [Indexed: 11/17/2022]
Abstract
Purpose To determine the hardness and Young's moduli of both commercial and experimental vinyl poly siloxane (VPS). Methods The purpose of this study was to develop a medium-bodied experimental (Exp-I, II, III, IV, and V) VPS impression materials and to analyse their effects on hardness and Young's modulus and compare them with three commercial VPS materials (Aquasil, Elite, and Extrude) using Shore A hardness tester. Measurements were recorded after 1, 24, 72, and 168 hours of mixing. The results were analysed with one-way ANOVA and post hoc Tukey's test using the SPSS PASW statistical 22 software. Results Commercial and experimental vinyl polysiloxane exhibited higher Shore A hardness values with time (i.e., 1 hour after mixing, 24 hours after mixing, 72 hours after mixing, and 1 week after mixing). All Comml and Exp VPS demonstrated a significant increase (ANOVA, p < 0.05) in hardness at increasing time points. Generally, all commercial VPS exhibited significantly higher values for Shore A hardness compared to all Exp formulations. For commercial products, Elt M presented significantly highest values at all-time points followed by Aq M then Extr M. Exp-I was significantly harder than all other Exp VPS at all-time points. Young's modulus values were directly related to Shore A hardness; materials with higher Shore A hardness values had higher Young's moduli. Conclusion Continued polymerisation of elastomeric impression materials results in increased hardness over time. Hardness, Young's moduli, and rigidity of the set commercial and experimental VPS materials were within the required limits. Shore A hardness and Young's moduli were directly proportional to each other, and commercial and experimental materials had enough rigidity to contain the stone during pouring.
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Prem N, Schale F, Zimmermann K, Gowda DK, Odenbach S. Synthesis and characterization of the properties of thermosensitive elastomers with thermoplastic and magnetic particles for application in soft robotics. J Appl Polym Sci 2021. [DOI: 10.1002/app.51296] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Nina Prem
- Technische Universität Ilmenau Ilmenau Germany
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Abstract
Purpose: Surgical simulation of microvascular anastomosis has become increasingly popular. There are several living and silicone models available. Current silicone models fail to accurately reproduce a vessel’s loose adventitial layer, which may lead to the development of improper microsurgical technique. Our purpose is to create a realistic 3-dimensional microsurgical simulator that incorporates an adventitial vessel layer for higher fidelity manipulation of vessels. Methods: A microvascular anastomosis simulator was manufactured using metal moulds and inorganic materials. Synthetic tubing was created with a metal cylinder, 1.65 mm in diameter, painted with 2 sequential layers of silicon with a shore hardness of 2A. Silicone was allowed to fully cure in-between layers. Vessel adventitia was created with a 100-micron polyester mesh adhered to the silicone vessel exterior. Once dry, the synthetic tube is removed from the metal cylinder is then clipped to reveal the inner lumen. Both Resident and attending physicians evaluated the model with and without the adventitial layer and completed a questionnaire. Results: Grasping and manipulation of the vessel were scored on Average score 4.5 and 3 out of 5, with adventitia and without, respectively ( P = .00906). Usefulness as a teaching tool was scored on average 4.9 and 4.2, with adventitia and without, respectively ( P = .0232). The analysis included: simulation realism, educational utility, and overall satisfaction. Responses in all domains were favourable, suggesting the utility of this model. Conclusion: We created a realistic, high fidelity microvascular anastomosis simulator that is low cost and easily reproducible. Initial feedback is encouraging regarding realism, educational utility, and overall usefulness. Further validation is required to assess its effectiveness in resident education and skill transfer to the operating room.
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Rodríguez-Prieto A, Primera E, Frigione M, Camacho AM. Reliability Prediction of Acrylonitrile O-Ring for Nuclear Power Applications Based on Shore Hardness Measurements. Polymers (Basel) 2021; 13:polym13060943. [PMID: 33808625 PMCID: PMC8003519 DOI: 10.3390/polym13060943] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 03/09/2021] [Accepted: 03/18/2021] [Indexed: 01/27/2023] Open
Abstract
The degradation of polymeric components is of considerable interest to the nuclear industry and its regulatory bodies. The objective of this work was the development of a methodology to determine the useful life—based on the storage temperature—of acrylonitrile O-rings used as mechanical sealing elements to prevent leakages in nuclear equipment. To this aim, a reliability-based approach that allows prediction of the use-suitability of different storage scenarios (that involve different storage times and temperatures) considering the further required in-service performance, is presented. Thus, experimental measurements of Shore A hardness have been correlated with storage variables (temperature and storage time). The storage (and its associated hardening) was proved to have a direct effect on in-service durability, reducing this by up to 60.40%. Based on this model, the in-service performance was predicted; after the first three years of operation the increase in probability of failure (POF) was practically insignificant. Nevertheless, from this point on, and especially, from 5 years of operation, the POF increased from 10% to 20% at approximately 6 years (for new and stored). From the study, it was verified that for any of the analysis scenarios, the limit established criterion was above that of the storage time premise considered in usual nuclear industry practices. The novelty of this work is that from a non-destructive test, like a Shore A hardness measurement, the useful life and reliability of O-rings can be estimated and be, accordingly, a decision tool that allows for improvement in the management of maintenance of safety-related equipment. Finally, it was proved that the storage strategies of our nuclear power plants are successful, perfectly meeting the expectations of suitability and functionality of the components when they are installed after storage.
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Affiliation(s)
- Alvaro Rodríguez-Prieto
- Department of Manufacturing Engineering, Universidad Nacional de Educación a Distancia (UNED), 28040 Madrid, Spain;
- Department of Industrial Inspection and Technical Assistance, SGS Tecnos, 28042 Madrid, Spain
- Correspondence: ; Tel.: +34-913-988-660
| | - Ernesto Primera
- Department of Applied Statistics, University of Delaware, 531 South College Avenue, Newark, DE 19716, USA;
- Machinery and Reliability Institute (MRI), 2149 Adair Ct. Mobile, AL 36695, USA
| | - Mariaenrica Frigione
- Department of Engineering for Innovation, University of Salento, Prov. le Lecce-Monteroni, 73100 Lecce, Italy;
| | - Ana María Camacho
- Department of Manufacturing Engineering, Universidad Nacional de Educación a Distancia (UNED), 28040 Madrid, Spain;
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Campelo S, Subashi E, Meltsner SG, Chang Z, Chino J, Craciunescu O. Multimaterial three-dimensional printing in brachytherapy: Prototyping teaching tools for interstitial and intracavitary procedures in cervical cancers. Brachytherapy 2020; 19:767-776. [PMID: 32893145 PMCID: PMC8488976 DOI: 10.1016/j.brachy.2020.07.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 07/06/2020] [Accepted: 07/16/2020] [Indexed: 01/27/2023]
Abstract
Purpose: As the utilization of brachytherapy procedures continues to decline in clinics, a need for accessible training tools is required to help bridge the gap between resident comfort in brachytherapy training and clinical practice. To improve the quality of intracavitary and interstitial HDR brachytherapy education, a multi-material modular 3D printed pelvic phantom prototype simulating normal and cervix pathological conditions has been developed. Methods and Materials: Patient anatomy was derived from pelvic CT and MRI scans from 50 representative patients diagnosed with localized cervical cancer. Dimensions measured from patients’ uterine body and uterine canal sizes were used to construct a variety of uteri based off of the averages and standard deviations of the subjects in our study. Soft-tissue anatomy was 3D printed using Agilus blends (shore 30 and 70), and modular components in Vero (shore 85). Results: The kit consists of four uteri, a standard bladder, standard rectum, two embedded GTVs and four clip-on GTV attachments. The three anteverted uteri in the kit are based on the smallest, the average, and the largest dimensions from our patient set while the retroverted uterus assumes average dimensions. Conclusions: This educational HDR gynecological pelvic phantom is an accessible and cost-effective way to improve radiation oncology resident training in intracavitary/interstitial brachytherapy cases. Implementation of this phantom in resident education will allow for more thorough and comprehensive physician training through its ability to transform the patient scenario. It is expected that this tool will help improve confidence and efficiency when performing brachytherapy procedures in patients.
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Affiliation(s)
- Sabrina Campelo
- Medical Physics Graduate Program, Duke University, Durham, NC.
| | - Ergys Subashi
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Sheridan G Meltsner
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC
| | - Zheng Chang
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC
| | - Junzo Chino
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC
| | - Oana Craciunescu
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC.
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Maluf CV, Janott-Sarlo CA, Bertolini MDM, Menezes LR, Lourenço EJV, Telles DDM. In vitro evaluation of physicochemical properties of soft lining resins after incorporation of chlorhexidine. J Prosthet Dent 2020; 124:615.e1-615.e7. [PMID: 32540125 DOI: 10.1016/j.prosdent.2020.03.027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 03/16/2020] [Accepted: 03/17/2020] [Indexed: 02/05/2023]
Abstract
STATEMENT OF PROBLEM Incorporating chlorhexidine into soft lining materials has been suggested to reduce biofilm development on the material surface and treat denture stomatitis. However, evaluation of the physicochemical properties of this material is necessary. PURPOSE The purpose of this in vitro study was to evaluate the physicochemical properties of resin-based denture soft lining materials modified with chlorhexidine diacetate (CDA). MATERIAL AND METHODS Two soft lining resins were tested, one based on polymethyl methacrylate (PMMA) and the other on polyethyl methacrylate (PEMA), into which 0.5%, 1.0%, or 2.0% of CDA was incorporated; the control group had no CDA. The specimens were stored for 2 hours, 48 hours, 7, 14, 21, and 28 days and then analyzed for polymer crystallinity, Shore A hardness, degree of monomer conversion, residual monomer leaching, and CDA release. Data were analyzed by using a 3-way ANOVA and the Tukey HSD test (α=.05). RESULTS The polymer crystallinity of PEMA and PMMA did not change after CDA incorporation. Shore A hardness increased over time, but not for any CDA concentrations tested after 28 days (P>.05). Considering the degree of conversion, PMMA-based resin showed no statistically significant difference (P>.05). However, PEMA-based resin showed a significant decrease (P<.05), which was reflected in a significant increase in residual monomer leaching from PEMA-based resin with the incorporation of 0.5% and 1.0% CDA (P<.05), mainly in the first 48 hours. PMMA-based resin showed no change in monomer leaching (P>.05). For both resins, the CDA release kinetics were related to monomer leaching; for PEMA-based resin, the values were significantly higher in the first 48 hours (P<.05), and for PMMA-based resin, the values were more sustained up to the last day of analysis. CONCLUSIONS The incorporation of CDA did not affect the physicochemical properties of soft resins. The properties of PMMA were better than those of PEMA.
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Affiliation(s)
- Caroline Vieira Maluf
- Postdoctoral student, Department of Prosthodontics, Rio de Janeiro State University, Rio de Janeiro, Brazil
| | | | | | - Lívia Rodrigues Menezes
- Adjunct Professor, Institute of Macromolecules Eloisa Mano, Rio de Janeiro Federal University, Rio de Janeiro, Brazil
| | | | - Daniel de Moraes Telles
- Full Professor, Department of Prosthodontics, Rio de Janeiro State University, Rio de Janeiro, Brazil.
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Maier J, Weiherer M, Huber M, Palm C. Optically tracked and 3D printed haptic phantom hand for surgical training system. Quant Imaging Med Surg 2020; 10:340-355. [PMID: 32190561 DOI: 10.21037/qims.2019.12.03] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Background For surgical fixation of bone fractures of the human hand, so-called Kirschner-wires (K-wires) are drilled through bone fragments. Due to the minimally invasive drilling procedures without a view of risk structures like vessels and nerves, a thorough training of young surgeons is necessary. For the development of a virtual reality (VR) based training system, a three-dimensional (3D) printed phantom hand is required. To ensure an intuitive operation, this phantom hand has to be realistic in both, its position relative to the driller as well as in its haptic features. The softest 3D printing material available on the market, however, is too hard to imitate human soft tissue. Therefore, a support-material (SUP) filled metamaterial is used to soften the raw material. Realistic haptic features are important to palpate protrusions of the bone to determine the drilling starting point and angle. An optical real-time tracking is used to transfer position and rotation to the training system. Methods A metamaterial already developed in previous work is further improved by use of a new unit cell. Thus, the amount of SUP within the volume can be increased and the tissue is softened further. In addition, the human anatomy is transferred to the entire hand model. A subcutaneous fat layer and penetration of air through pores into the volume simulate shiftability of skin layers. For optical tracking, a rotationally symmetrical marker attached to the phantom hand with corresponding reference marker is developed. In order to ensure trouble-free position transmission, various types of marker point applications are tested. Results Several cuboid and forearm sample prints lead to a final 30 centimeter long hand model. The whole haptic phantom could be printed faultless within about 17 hours. The metamaterial consisting of the new unit cell results in an increased SUP share of 4.32%. Validated by an expert surgeon study, this allows in combination with a displacement of the uppermost skin layer a good palpability of the bones. Tracking of the hand marker in dodecahedron design works trouble-free in conjunction with a reference marker attached to the worktop of the training system. Conclusions In this work, an optically tracked and haptically correct phantom hand was developed using dual-material 3D printing, which can be easily integrated into a surgical training system.
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Affiliation(s)
- Johannes Maier
- Regensburg Medical Image Computing (ReMIC), Ostbayerische Technische Hochschule Regensburg (OTH Regensburg), Regensburg, Germany
| | - Maximilian Weiherer
- Regensburg Medical Image Computing (ReMIC), Ostbayerische Technische Hochschule Regensburg (OTH Regensburg), Regensburg, Germany
| | - Michaela Huber
- Department of Trauma Surgery & Emergency Department, University Hospital Regensburg, Regensburg, Germany
| | - Christoph Palm
- Regensburg Medical Image Computing (ReMIC), Ostbayerische Technische Hochschule Regensburg (OTH Regensburg), Regensburg, Germany.,Regensburg Center of Biomedical Engineering (RCBE), OTH Regensburg and Regensburg University, Regensburg, Germany
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Rivera Nicholls A, Pellisier M, Perez Y, Stock JA, Kull K, Julien T, Eubank J, Harmon JP. Thermomechanical characterization of thermoplastic polyimide–polyurea to improve the chain interaction via internal hydrogen bonds. POLYM ENG SCI 2019. [DOI: 10.1002/pen.25196] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
| | | | | | | | - Ken Kull
- University of South Florida Tampa Florida 33620
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Nowakowska-Toporowska A, Malecka K, Raszewski Z, Wieckiewicz W. Changes in hardness of addition-polymerizing silicone-resilient denture liners after storage in artificial saliva. J Prosthet Dent 2018; 121:317-321. [PMID: 30093127 DOI: 10.1016/j.prosdent.2018.05.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 05/15/2018] [Accepted: 05/15/2018] [Indexed: 11/25/2022]
Abstract
STATEMENT OF PROBLEM The hardness of silicone resilient denture liners was reported to be more stable than that of acrylic resin resilient denture liners. However, the changes in hardness of these materials in artificial saliva are unclear. PURPOSE The purpose of this in vitro study was to evaluate changes in the hardness of addition-polymerizing silicone-resilient denture liners for long-term use after storage in artificial saliva. MATERIAL AND METHODS Four addition-polymerizing silicone resilient denture liners were tested: GC Reline Soft, Elite Soft Relining, Megabase, and Mucopren Soft. All were long-term relining materials of the soft type. Fifteen disk-shaped specimens were prepared for each of the tested materials (40 mm in base diameter, 8 mm in thickness). Their initial hardness was assessed with a Shore A durometer, after which they were stored in artificial saliva at a temperature of 37°C. Hardness was examined after 7, 30, and 90 days. Statistical analysis was performed using parametric ANOVA for dependent and independent variables and Tukey honest significant difference (HSD) post hoc tests (α=.05). RESULTS All resilient denture liners increased in hardness during the experiment. The change was least for Elite Soft Relining, and GC Reline Soft was the hardest material. Initially, Megabase and Mucopren Soft were significantly softer than the other 2 materials, but their hardness increased rapidly after the first 7 days of specimen conditioning, achieving values close to Elite Soft Relining. CONCLUSIONS Within the limitations of the study, room temperature vulcanizing addition-polymerizing polyvinyl siloxanes of the soft type have different initial hardness, and this changes with storage time in artificial saliva at the temperature of the oral cavity.
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Affiliation(s)
| | - Krystyna Malecka
- Research Associate Professor, Department of Drug Technology, Wroclaw Medical University, Wroclaw, Poland
| | - Zbigniew Raszewski
- Laboratory Technician, Department of Prosthodontics, Wroclaw Medical University, Wroclaw, Poland
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Kanazawa T, Murayama R, Furuichi T, Imai A, Suda S, Kurokawa H, Takamizawa T, Miyazaki M. Ultrasonic monitoring of the setting of silicone elastomeric impression materials. Dent Mater J 2017; 36:63-68. [PMID: 27928107 DOI: 10.4012/dmj.2016-175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This study used an ultrasonic measurement device to monitor the setting behavior of silicone elastomeric impression materials, and the influence of temperature on setting behavior was determined. The ultrasonic device consisted of a pulser-receiver, transducers, and an oscilloscope. The two-way transit time through the mixing material was divided by two to account for the down-and-back travel path; then it was multiplied by the sonic velocity. Analysis of variance and the Tukey honest significant difference test were used. In the early stages of the setting process, most of the ultrasonic energy was absorbed by the elastomers and the second echoes were relatively weak. As the elastomers hardened, the sonic velocities increased until they plateaued. The changes in sonic velocities varied among the elastomers tested, and were affected by temperature conditions. The ultrasonic method used in this study has considerable potential for determining the setting processes of elastomeric impression materials.
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Affiliation(s)
- Tomoe Kanazawa
- Department of Operative Dentistry, Nihon University School of Dentistry
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Chladek G, Żmudzki J, Kasperski J. Long-Term Soft Denture Lining Materials. MATERIALS 2014; 7:5816-5842. [PMID: 28788163 PMCID: PMC5456172 DOI: 10.3390/ma7085816] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 07/31/2014] [Accepted: 08/01/2014] [Indexed: 11/16/2022]
Abstract
Long-term soft denture lining (LTSDL) materials are used to alleviate the trauma associated with wearing complete dentures. Despite their established clinical efficacy, the use of LTSDLs has been limited due to the unfavorable effects of the oral environment on some of their mechanical and performance characteristics. The unresolved issue of LTSDL colonization by Candida albicans is particularly problematic. Silicone-based LTSDL (SLTSDL) materials, which are characterized by more stable hardness, sorption and solubility than acrylic-based LTSDLs (ALTSDLs), are currently the most commonly used LTSDLs. However, SLTSDLs are more prone to debonding from the denture base. Moreover, due to their limitations, the available methods for determining bond strength do not fully reflect the actual stability of these materials under clinical conditions. SLTSDL materials exhibit favorable viscoelastic properties compared with ALTSDLs. Furthermore, all of the lining materials exhibit an aging solution-specific tendency toward discoloration, and the available cleansers are not fully effective and can alter the mechanical properties of LTSDLs. Future studies are needed to improve the microbiological resistance of LTSDLs, as well as some of their performance characteristics.
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Affiliation(s)
- Grzegorz Chladek
- Faculty of Mechanical Engineering, Institute of Engineering Materials and Biomaterials, Silesian University of Technology, ul. Konarskiego 18a, Gliwice 44-100, Poland.
| | - Jarosław Żmudzki
- Faculty of Mechanical Engineering, Institute of Engineering Materials and Biomaterials, Silesian University of Technology, ul. Konarskiego 18a, Gliwice 44-100, Poland.
| | - Jacek Kasperski
- Department of Prosthetic Dentistry, Medical University of Silesia, pl. Akademicki 17, Bytom 41-902, Poland.
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Çopuroğlu M, Şen M. Synthesis and characterization of a Zr-containing silicate-based epoxy-functional polymer nanocomposite system. POLYM ENG SCI 2014. [DOI: 10.1002/pen.23946] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Mehmet Çopuroğlu
- Department of Chemistry; Polymer Chemistry Division; Hacettepe University; Beytepe 06800 Ankara Turkey
| | - Murat Şen
- Department of Chemistry; Polymer Chemistry Division; Hacettepe University; Beytepe 06800 Ankara Turkey
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Bertolini MM, Portela MB, Curvelo JAR, Soares RMA, Lourenço EJV, Telles DM. Resins-based denture soft lining materials modified by chlorhexidine salt incorporation: an in vitro analysis of antifungal activity, drug release and hardness. Dent Mater 2014; 30:793-8. [PMID: 24933229 DOI: 10.1016/j.dental.2014.05.004] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2013] [Revised: 12/22/2013] [Accepted: 05/07/2014] [Indexed: 11/18/2022]
Abstract
OBJECTIVES To evaluate the in vitro growth inhibition of Candida albicans, the rate of chlorhexidine release and shore A hardness from resins-based denture soft lining materials modified by chlorhexidine diacetate (CDA) or chlorhexidine hydrochloride (CHC) incorporation. METHODS Resin discs were prepared from soft denture liners based on poly (methyl methacrylate) (PMMA) or poly (ethyl methacrylate) (PEMA) containing 0.5, 1.0 and 2.0 wt.% of CDA or CHC. For antifungal activity resin discs were placed on agar plates inoculated with C. albicans, after 48 h at 37°C the diameters of inhibition zones were measured. For the chlorhexidine release, discs were immersed into distilled water at 37°C, and spectral measurements were made after 48 h. Shore A hardness was evaluated at the baseline, 2 and 7 days, using 6mm thick rectangular specimens also immersed into distilled water at 37°C. Data were statistically processed by SigmaStat software using ANOVA and all pairwise multiple comparison procedures was done using the Holm-Sidak method, with α=0.05 (p<0.001). RESULTS CDA added to PMMA soft liner and PEMA soft liner had a dose-related inhibitory effect on C. albicans and on chlorhexidine release rate (p<0.001). The PMMA and PEMA hardness increased statistically by time but not for the different CDA concentrations. CHC had no inhibitory effect on C. albicans. SIGNIFICANCE Chlorhexidine diacetate released from resins-based soft lining materials can be convenient to reduce the biofilm development on the material surface and treat denture stomatitis, without depending on patient compliance.
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Affiliation(s)
- Martinna M Bertolini
- Department of Prosthodontics, Dental School, State University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
| | - Maristela B Portela
- Department of Clinics, Pediatric Dentistry, School of Dentistry, Fluminense Federal University, Niteroi, Rio de Janeiro, Brazil
| | - José Alexandre R Curvelo
- Institute of Microbiology Professor Paulo de Góes, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Rosangela M A Soares
- Institute of Microbiology Professor Paulo de Góes, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Eduardo J V Lourenço
- Department of Prosthodontics, Dental School, State University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Daniel M Telles
- Department of Prosthodontics, Dental School, State University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
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Çopuroğlu M, Şen M. Identification of relationship between the synthesis/process parameters and properties of a sol-gel-derived polymer nanocomposite system. J Appl Polym Sci 2013. [DOI: 10.1002/app.39129] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Çopuroğlu M, Şen M. Ultraviolet-radiation-curing of an organically modified silicate-based material system with epoxy functionality, and the role of titanium. Radiat Phys Chem Oxf Engl 1993 2012. [DOI: 10.1016/j.radphyschem.2011.11.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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