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Artopoulou II, Chambers MS, Polychronis G, Papadopoulos F, Economou A, Zinelis S. Effect of in vivo aging on the surface and electrochemical properties of magnetic attachments used in facial prostheses: A retrieval analysis study. J Prosthet Dent 2024:S0022-3913(23)00781-3. [PMID: 38184396 DOI: 10.1016/j.prosdent.2023.11.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 11/18/2023] [Accepted: 11/20/2023] [Indexed: 01/08/2024]
Abstract
STATEMENT OF PROBLEM Reasons associated with the failure of facial prosthesis are of major concern and may be associated with deterioration of both elastomeric materials and magnetic attachments. However, the extent of deterioration of these components is unclear. PURPOSE The purpose of this in vitro study was to evaluate selected retrieved facial prostheses and provide information regarding the electrochemical characterization of the recovered magnetic attachments. MATERIAL AND METHODS Five facial prostheses (RP1, RP2, RP3, RP4, RP5) fabricated at the University of Texas, M.D. Anderson Cancer Center were retrieved following clinical use. The intaglio and external surfaces of the prostheses along with the incorporated magnetic attachments were photographed. The areas with the detected failures on the retrieved prostheses, as well as the recovered magnetic attachments, were evaluated under a reflected light stereomicroscope at ×16 nominal magnification and photographed with a digital camera. Five magnetic attachments recovered from the prostheses (retrieved group RT) were evaluated for degradation of their corrosion resistance after electrochemical testing in artificial sweat solution and were compared with 5 unused magnetic attachments (control group, CT). To identify the elemental composition of the intact magnet surface, 1 specimen from the control group was investigated by X-ray energy dispersive spectroscopy (EDS). Means and standard deviations of the open circuit potential (EOCP), the zero-circuit potential (Ecorr), and Icorr were calculated and statistically analyzed by a t test (α=.05 for all tests). RESULTS The main reasons of failure were discoloration, degradation and rupture of the silicone elastomer, marginal misfit, and delamination of the polyurethane sheet. Additional findings were tarnish and discoloration of the magnetic attachments accompanied by considerable smear build-up. EDS results verified the Ni plating of tested magnets. Electrochemical testing revealed that retrieved magnets showed significantly lower OCP (P<.001) and Ecorr (P<.001) but similar Icorr (P=0.083) while the pseudopassivity region of unused magnets vanished in the retrieved group, denoting a degradation of electrochemical properties after clinical use. CONCLUSIONS In vivo aging exerts extended degradation on the elastomer part of facial prostheses as well as deterioration of their surface integrity and electrochemical properties.
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Affiliation(s)
- Ioli Ioanna Artopoulou
- Assistant Professor, Department of Prosthodontics, School of Dentistry, National and Kapodistrian University of Athens, Athens, Greece; and f.Fellow, Section of Oral Oncology and Maxillofacial Prosthodontics, The University of Texas, M.D. Anderson Cancer Center, Houston, Texas.
| | - Mark S Chambers
- Professor and Deputy Chair, Department of Head and Neck Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas; and Chief and Medical Director, Section of Oral Oncology and Maxillofacial Prosthodontics, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Georgios Polychronis
- Research Fellow, Department of Biomaterials, School of Dentistry, National and Kapodistrian University of Athens, Athens, Greece
| | - Frixos Papadopoulos
- Postgraduate student, Laboratory of Analytical Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Athens, Greece
| | - Anastasios Economou
- Professor, Laboratory of Analytical Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Athens, Greece
| | - Spiros Zinelis
- Professor, Department of Biomaterials, School of Dentistry, National and Kapodistrian University of Athens, Athens, Greece
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Hatamleh MM, Maqableh AM, Al-Wahadni A, Al-Rabab'ah MA. Mechanical properties and bonding of maxillofacial silicone elastomer mixed with nano-sized anti-microbials. Dent Mater 2023; 39:677. [PMID: 37271602 DOI: 10.1016/j.dental.2023.05.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Revised: 05/14/2023] [Accepted: 05/15/2023] [Indexed: 06/06/2023]
Abstract
OBJECTIVES The antibacterial efficacy of silicone is improved by impregnating it with antimicrobials such as chlorohexidine and zinc oxide. The purpose of this study was to examine mechanical properties and bonding of maxillofacial silicone elastomer mixed with Zinc Oxide nanoparticles (ZnO-NP), and Chlorohexidine Diacetate Salt (CHX) at three different concentrations (1 %, 3 %, and 5 %). METHODS Specimens of a silicone elastomer (M511) were prepared and divided into 7 groups. Group 1 was control of no additive. Groups 2-4 included silicone elastomer mixed with ZnO-NP (surface area = 67 m2/g) at 3 different concentrations (by weight %); 1 %, 3 % and 5 %. Groups 5-7 included silicone elastomer mixed with CHX at the same concentrations. Tear and tensile strengths, elongation percentage, modulus of elasticity, and shear bond strength to primed acrylic resin surfaces were evaluated. Data was analyzed with 1-way ANOVA, Bonferroni, and Dunnett's T3 post-hoc tests (P < 0.05). RESULTS There was significant effect of the additives on the tensile strength, elongation percentage, tear strength, and shear bond strength (P < 0.05). Shear bond strengths ranged from 0.55 to 0.96 MPa. Silicone elastomer mixed with CHX (5 %) resulted in the highest shear bond strength (P < 0.05). Non-linear regressions between tensile strength and ZnO and CHX additives were 0.95 and 0.96 respectively. SIGNIFICANCE All additives reduced the tensile strength of the silicone. However, CHX at 5 % optimized shear bond strength and thus is proposed in order to fabricate maxillofacial prostheses of sufficient mechanical properties, bonding and antimicrobial activity.
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Affiliation(s)
- Muhanad M Hatamleh
- School of Applied Medical Science, Luminus Technical University College (LTUC), Amman, Jordan.
| | - Ayman M Maqableh
- School of Electro-Mechanical Engineering, Luminus Technical University College (LTUC), Amman, Jordan
| | - Ahed Al-Wahadni
- Faculty of Dentistry, Jordan University of Science and Technology, Irbid, Jordan
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Spintzyk S, Brinkmeier S, Huettig F, Unkovskiy A. Bonding strength of 3D printed silicone and titanium retention magnets for maxillofacial prosthetics application. J Prosthodont Res 2021; 66:422-430. [PMID: 34545007 DOI: 10.2186/jpr.jpr_d_21_00019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
PURPOSE To assess the bonding between conventional and additively manufactured silicone elastomers and cylindrical retention titanium magnets for anchorage of facial prostheses. METHODS The customized titanium retention magnets were embedded in conventional and additively produced silicone blocks without primer application (n = 20) and with two commercially available primers G611 (n = 20) and A304 (n = 20) applied onto the magnet surface. The pull out test was performed in the universal testing machine using 45° and 90° angulation and the pull out strength was measured for each group. Additionally the SEM images of the pulled out magnets' surface were obtained and the amount of residual silicone onto the magnet surface was quantified. RESULTS Significantly higher pull out strength values (p < 0.05) were revealed for 90° specimens (0.11 - 0.17 ± 0.01 N/mm2) compared to the 45° group (0.03 ± 0.02 N/mm2). The pull out test with primer revealed no significant differences between the G 611 and A 304 primers in the additive group. However, significantly (p < 0,05) higher values were observed for conventional specimens in the A304 group (1.10 ± 0.21 N/mm2) compared to the G611 group (0.59 ± 0.27 N/mm2). CONCLUSION The application of both used primers may be an acceptable technical option for the anchorage of retention titanium magnets in silicone facial prostheses, produced additively in a fully digital workflow.
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Affiliation(s)
- Sebastian Spintzyk
- Section Medical Materials Science and Technology, Tuebingen University Hospital, Tuebingen, Germany
| | - Sophia Brinkmeier
- Section Medical Materials Science and Technology, Tuebingen University Hospital, Tuebingen, Germany
| | - Fabian Huettig
- Department of Prosthodontics at the Centre of Dentistry, Oral Medicine, and Maxillofacial Surgery with Dental School, Tuebingen University Hospital, Tuebingen, Germany
| | - Alexey Unkovskiy
- Department of Prosthodontics, Geriartric Dentistry and Craniomandibular Disorders, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt - Universität zu Berlin, Berlin, Germany.,Department of Dental Surgery, Sechenov First Moscow State Medical University, Moscow, Russia
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Artopoulou II, Chambers MS, Eliades G. Porosity of maxillofacial silicone elastomers and microleakage pattern of the commercially pure Ti-silicone elastomer interface after hydrothermal cycling. J Prosthet Dent 2016; 116:937-942. [PMID: 27460319 DOI: 10.1016/j.prosdent.2016.05.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 05/26/2016] [Accepted: 05/27/2016] [Indexed: 11/19/2022]
Abstract
STATEMENT OF PROBLEM Delamination of the maxillofacial silicone elastomer away from the commercially pure titanium (cpTi)-encapsulated magnets affects the long-term performance of the facial restoration. PURPOSE The purposes of this in vitro study were to investigate the interfacial microleakage patterns of 2 maxillofacial silicone elastomers with cpTi when 3 different primers were used and to evaluate the porosity of the 2 elastomers tested. MATERIAL AND METHODS To test the interfacial microleakage patterns of the 2 elastomers MDX4-4210 (EL1) and A-2006 (EL2) with cpTi when 3 metal primers, A-304 (PR1), A-320 bonding enhancer (PR2), Super-Bond C&B monomer (PR3), and ethyl-cyanoacrylate (Super Glue) were used, the bonded interfaces were observed using reflected light microscopy, and the percentage of the linear extent of leakage along the interface (%microleakage) was measured. High-resolution x-ray computed microtomography scanning was used to investigate the percentage of void volume fraction (%VF) for both silicone EL1 and EL2. The data were analyzed with 2-way ANOVA and post hoc tests (α=.05). RESULTS No statistically significant differences were found among the percentages of PR1, PR2, and PR3 microleakage, whereas ethyl-cyanoacrylate showed a statistically significant higher percentage of microleakage than either of the silicone elastomers (P<.001). EL1 medical grade elastomer groups have always had a statistically significantly higher percentage of microleakage than the EL2 platinum silicone elastomer groups (P<.001). For both elastomers, no statistically significant differences were found in %VF (P=.056). CONCLUSIONS Differences in mechanical properties, chemical composition, and manipulations during handling of the maxillofacial silicone elastomers can affect the linear microleakage along the cpTi-silicone elastomer bonding interface and the porosity of the silicone elastomer.
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Affiliation(s)
- Ioli Ioanna Artopoulou
- Lecturer, Department of Prosthodontics, National and Kapodistrian University of Athens, School of Dentistry, Athens, Greece.
| | - Mark S Chambers
- Professor, Section of Maxillofacial Prosthodontics and Oncologic Dentistry, Department of Head and Neck Surgery, Division of Surgery, the University of Texas MD Anderson Cancer Center, Houston, Texas
| | - George Eliades
- Professor, Department of Biomaterials, National and Kapodistrian University of Athens, School of Dentistry, Athens, Greece
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Artopoulou II, Chambers MS, Zinelis S, Eliades G. Peel strength and interfacial characterization of maxillofacial silicone elastomers bonded to titanium. Dent Mater 2016; 32:e137-47. [PMID: 27118682 DOI: 10.1016/j.dental.2016.03.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 01/05/2016] [Accepted: 03/22/2016] [Indexed: 11/25/2022]
Abstract
OBJECTIVES To investigate the effect of three adhesive primers on the morphology, chemistry and peel bond strength of two maxillofacial silicone elastomers with commercially pure titanium (cpTi). METHODS The effect of three primers (PR2:A-304 Primer/A-320 Bonding Enhancer, PR3:Super Bond, and PR4:Super Glue) on cpTi morphology and chemistry were studied by reflected light polarized microscopy (RPOLM) and reflection Fourier-transform infrared microspectroscopy (RFTIRM). For testing the bond strength between two elastomers (EL1:MDX4-4210, EL2:A-2006) and primed cpTi surfaces, a 90° T peel test was performed (PBS), using as reference EL1, EL2 specimens bonded to heat-cured poly(methyl methacrylate) resin (PMMA) primed with A-330G primer (PR1). Failure modes were analyzed under a stereomicroscope, and the percentage of remaining silicone (RS%) on cpTi and PMMA were calculated by image analysis. Scanning electron microscopy/energy dispersive X-ray spectrometry (SEM/EDX) was used to investigate representative failure patterns on cpTi. Data were analyzed with Weibull analysis, ANOVA plus post hoc tests, and Pearson correlation coefficient (a=0.05). RESULTS Thick-irregular (PR2), thin-smooth (PR3), and uniform-porous (PR4) films were identified on cpTi by RPOLM. RFTIRM revealed: a strong peak of Si-O-Si with a distribution following the outline of the image (PR2); COO-M groups developed, but unevenly distributed (PR3); and reduction in CC groups due to in situ polymerization (PR4). Following PBS, the ranking of the statistical significant differences in Weibull scale parameter (σ0) of the EL1 group was PMMA_PR1>cpTi_PR2,cpTi_PR3>cpTi_PR4, whereas for the EL2 group cpTi_PR2>PMMA_PR1>cpTi_PR4,cpTi_PR3. For RS%, the ranking in the EL1 group was: PMMA_PR1>cpTi_PR2>cpTi_PR3>cpTi_PR4, and in the EL2 cpTi_PR2>cpTi_PR3>cpTi_PR4,PMMA_PR1. There was no statistically significant correlation between PBS and RS%, with the exception of EL1_PMMA_PR1. In all groups mixed failure modes were found by SEM/EDX. SIGNIFICANCE Although there is evidence of bonding with cpTi, there are important differences among the primer/elastomer combination that may affect the clinical performance of these materials.
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Affiliation(s)
- Ioli Ioanna Artopoulou
- Department of Prosthodontics, National and Kapodistrian University of Athens, School of Dentistry, Athens, Greece.
| | - Mark S Chambers
- Section of Maxillofacial Prosthodontics and Oncologic Dentistry, Department of Head and Neck Surgery, Division of Surgery, The University of Texas MD Anderson Cancer Center, Houston, USA
| | - Spiros Zinelis
- Department of Biomaterials, National and Kapodistrian University of Athens, School of Dentistry, 2 Thivon Str., 11 527 Goudi, Athens, Greece
| | - George Eliades
- Department of Biomaterials, National and Kapodistrian University of Athens, School of Dentistry, 2 Thivon Str., 11 527 Goudi, Athens, Greece
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Yerci Kosor B, Artunç C, Şahan H. Adhesive retention of experimental fiber-reinforced composite, orthodontic acrylic resin, and aliphatic urethane acrylate to silicone elastomer for maxillofacial prostheses. J Prosthet Dent 2015; 114:142-8. [DOI: 10.1016/j.prosdent.2014.12.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 12/18/2014] [Accepted: 12/18/2014] [Indexed: 11/22/2022]
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Polyzois G, Pantopoulos A, Papadopoulos T, Hatamleh M. Effect of light aging on silicone-resin bond strength in maxillofacial prostheses. J Prosthodont 2014; 24:215-9. [PMID: 25081922 DOI: 10.1111/jopr.12202] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/07/2014] [Indexed: 11/30/2022] Open
Abstract
PURPOSE The aim of this study was to investigate the effect of accelerated light aging on bond strength of a silicone elastomer to three types of denture resin. MATERIALS AND METHODS A total of 60 single lap joint specimens were fabricated with auto-, heat-, and photopolymerized (n = 20) resins. An addition-type silicone elastomer (Episil-E) was bonded to resins treated with the same primer (A330-G). Thirty specimens served as controls and were tested after 24 hours, and the remaining were aged under accelerated exposure to daylight for 546 hours (irradiance 765 W/m(2) ). Lap shear joint tests were performed to evaluate bond strength at 50 mm/min crosshead speed. Two-way ANOVA and Tukey's test were carried out to detect statistical significance (p < 0.05). RESULTS ANOVA showed that the main effect of light aging was the most important factor determining the shear bond strength. The mean bond strength values ranged from 0.096 to 0.136 MPa. The highest values were recorded for auto- (0.131 MPa) and photopolymerized (0.136 MPa) resins after aging. CONCLUSIONS Accelerated light aging for 546 hours affects the bond strength of an addition-type silicone elastomer to three different denture resins. The bond strength significantly increased after aging for photo- and autopolymerized resins. All the bonds failed adhesively.
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Affiliation(s)
- Gregory Polyzois
- Associate Professor and Chief of Maxillofacial Prosthetics Unit, Department of Prosthodontics, Dental School, University of Athens, Athens, Greece
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Banerjee S, Kumar S, Chakraborty N, Gupta T, Banerjee A. Prosthodontic Rehabilitation of Velopharyngeal Disorders—A Case Series. J Indian Prosthodont Soc 2012; 13:352-7. [DOI: 10.1007/s13191-012-0161-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2011] [Accepted: 07/16/2012] [Indexed: 11/29/2022] Open
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Hatamleh MM, Watts DC. Effects of bond primers on bending strength and bonding of glass fibers in fiber-embedded maxillofacial silicone prostheses. J Prosthodont 2011; 20:113-9. [PMID: 21323761 DOI: 10.1111/j.1532-849x.2010.00653.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
PURPOSE To evaluate the effect of three commonly used bond primers on the bending strength of glass fibers and their bond strength to maxillofacial silicone elastomer after 360 hours of accelerated daylight aging. MATERIALS AND METHODS Eighty specimens were fabricated by embedding resin-impregnated fiber bundles (1.5-mm diameter, 20-mm long) into maxillofacial silicone elastomer M511 (Cosmesil). Twenty fiber bundles served as control and did not receive surface treatment with primers, whereas the remaining 60 fibers were treated with three primers (n = 20): G611 (Principality Medical), A-304 (Factor II), and A-330-Gold (Factor II). Forty specimens were dry stored at room temperature (23 ± 1°C) for 24 hours, and the remaining specimens were aged using an environmental chamber under accelerated exposure to artificial daylight for 360 hours. The aging cycle included continuous exposure to quartz-filtered visible daylight (irradiance 760 W/m(2) ) under an alternating weathering cycle (wet for 18 minutes, dry for 102 minutes). Pull-out tests were performed to evaluate bond strength between fiber bundles and silicone using a universal testing machine at 1 mm/min crosshead speed. A 3-point bending test was performed to evaluate the bending strength of the fiber bundles. One-way Analysis of Variance (ANOVA), Bonferroni post hoc test, and an independent t-test were carried out to detect statistical significances (p < 0.05). RESULTS Mean (SD) values of maximum pull-out forces (N) before aging for groups: no primer, G611, A-304, A-330-G were: 13.63 (7.45), 20.44 (2.99), 22.06 (6.69), and 57.91 (10.15), respectively. All primers increased bond strength in comparison to control specimens (p < 0.05). Primer A-330-G showed the greatest increase among all primers (p < 0.05); however, bonding degraded after aging (p < 0.05), and pull-out forces were 13.58 (2.61), 6.17 (2.89), 6.95 (2.61), and 11.72 (3.03). Maximum bending strengths of fiber bundles at baseline increased after treatment with primers and light aging in comparison with control specimens (p < 0.05), and were in the range of 917.72 to 1095.25 and 1124.06 to 1596.68 MPa at both baseline and after 360 hours aging (p < 0.05). CONCLUSIONS The use of A-330-G primer in conjunction with silicone Cosmesil M511 produced the greatest bond strength for silicone-glass fiber surfaces at baseline; however, bond strength was significantly degraded after accelerated daylight aging. Treatment with primer and accelerated daylight aging increased bending strength of glass fibers.
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Affiliation(s)
- Muhanad M Hatamleh
- Department of Allied Dental Science/Faculty of Applied Medical Sciences, Jordan University of Science and Technology, Irbid, Jordan.
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Akin H, Coskun ME, Akin EG, Ozdemir AK. Multidisciplinary approach for esthetic, functional, and quality-of-life outcome in soft palate cleft patient. Cleft Palate Craniofac J 2011; 49:622-5. [PMID: 21309655 DOI: 10.1597/10-167] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The fabrication of a Suersen obturator prosthesis with titanium framework is described in the case of a 43-year-old man with congenital absence of the soft palate. The patient revealed an open soft palate, bilateral cleft lip and palate, Angle Class III dental malocclusion, and anterior and posterior crossbite. He was treated with a multidisciplinary approach. A Dolder bar was fabricated between the maxillary canines, and telescopic crowns were prepared for maxillary premolars. Angle Class III tooth relation was readjusted to tooth-tooth relation; closure of the nasopharynx and oropharynx was performed by Suersen method, which improves speech.
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Affiliation(s)
- Hakan Akin
- Department of Prosthodontics, Cumhuriyet University, 58140 Sivas, Turkey.
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Hatamleh MM, Watts DC. Effects of Accelerated Artificial Daylight Aging on Bending Strength and Bonding of Glass Fibers in Fiber-Embedded Maxillofacial Silicone Prostheses. J Prosthodont 2010; 19:357-63. [DOI: 10.1111/j.1532-849x.2010.00584.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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Hatamleh MM, Watts DC. Mechanical properties and bonding of maxillofacial silicone elastomers. Dent Mater 2010; 26:185-91. [DOI: 10.1016/j.dental.2009.10.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Revised: 10/01/2009] [Accepted: 10/03/2009] [Indexed: 11/26/2022]
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Minami H, Suzuki S, Minesaki Y, Kurashige H, Tanaka T. In Vitro Evaluation of the Effect of Thermal and Mechanical Fatigues on the Bonding of an Autopolymerizing Soft Denture Liner to Denture Base Materials Using Different Primers. J Prosthodont 2008; 17:392-400. [DOI: 10.1111/j.1532-849x.2008.00304.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Lehmann P, Symietz C, Brezesinski G, Krass H, Kurth DG. Langmuir and langmuir-blodgett films of metallosupramolecular polyelectrolyte-amphiphile complexes. Langmuir 2005; 21:5901-6. [PMID: 15952840 DOI: 10.1021/la050841p] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
A detailed analysis of a metallosupramolecular polyelectrolyte-amphiphile complex (PAC) at the air-water interface is presented. Langmuir isotherms, Brewster angle microscopy, and X-ray reflectance and diffraction methods are employed to investigate the structure of the Langmuir monolayers. The PAC is self-assembled from 1,3-bis[4'-oxa-(2,2':6',2' '-terpyridinyl)]propane, iron acetate, and dihexadecyl phosphate (DHP). Spreading the PAC at the air-water interface results in a monolayer that consists of two strata. DHP forms a monolayer at the top of the interface, while the metallosupramolecular polyelectrolyte is immersed in the aqueous subphase. Both strata are coupled to each other through electrostatic interactions. The monolayers can be transferred onto solid substrates, resulting in well-ordered multilayers. Such multilayers are model systems for well-ordered metal ions in two dimensions.
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Affiliation(s)
- Pit Lehmann
- Max Planck Institute of Colloids and Interfaces D-14424 Potsdam Germany
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Abstract
This study evaluated the effects of surface pre-treatments on the bonding of auto-polymerizing silicone soft denture liner to a Co-Cr alloy denture base after cyclic thermal stressing. The bonding surfaces of Co-Cr alloy cylinders (8 mm diameter and 4 mm high) were polished with a 600-grit silicon carbide paper. The bonding surfaces received one of three pre-treatments, which included either the application of a metal primer, a metal primer after air abrasion, or a resin primer after adhesive resin coating. Tensile specimens were fabricated by polymerizing a 2-mm thickness of soft denture liner between a pair of pre-treated denture base cylinders. Failure loads were measured by tensile testing after subjecting the specimen to 0, 5, 10, 20, and 30 thousand thermal cycles. Seven specimens were fabricated for 15 groups, including three pre-treatments and five thermal cycle groups. Failure loads of resin-bonded specimens, which were formerly reported, were used as references. All data were statistically analysed by two-way anova and Bonferroni test at the 95% confidence level. Adhesive resin coating of the metal surface was effective in enhancing the failure loads up to 5000 thermal cycles. However, failure loads of all metal-bonded groups were significantly lower than those of resin-bonded groups at all thermal cycling intervals. The results of this in vitro study implied that polymerizing adhesive resin on the Co-Cr alloy might be a promising method, when the clinicians need to acquire improved bonding of an auto-polymerizing soft denture liner to Co-Cr alloy denture bases.
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Affiliation(s)
- H Minami
- Department of Fixed Prosthodontics, Kagoshima University Dental School, Kagoshima-shi, Kagoshima, Japan.
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Meister A, Förster G, Thünemann AF, Kurth DG. Nanoscopic Structure of a Metallo-supramolecular Polyelectrolyte-Amphiphile Complex, Elucidated by X-ray Scattering and Molecular Modeling. Chemphyschem 2003; 4:1095-100. [PMID: 14596007 DOI: 10.1002/cphc.200300702] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A combination of molecular modeling and X-ray scattering was used to elucidate the structure of the metallosupramolecular polyelectrolyte--amphiphile complex (PAC) self-assembled from FeII, 1,4-bis(2,2':6,'2"-terpyridin-4'-yl)benzene, and dihexadecyl phosphate (DHP). An approximate structure of the semi-ordered material was derived from the analysis of the X-ray scattering data. The experimental data provided sufficient input for obtaining a useful starting configuration for molecular modeling. Various models of the supramolecular architecture are presented and discussed in terms of their total energies and scattering patterns. In an iterative approach each level of the structural hierarchy was refined until satisfactory agreement of calculated and experimental scattering patterns was reached. The remarkable sensitivity of the simulated scattering curves to even the smallest structural changes at all length scales restricts the arbitrariness of modeling. The final model of PAC consists of flat lamellae of alternating strata of interdigitated DHP monolayers and nematically ordered polyelectrolyte chains.
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Affiliation(s)
- Annette Meister
- Max Planck Institute of Colloids and Interfaces, 14476 Golm, Germany
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