1
|
Gradinariu AI, Racles C, Stoica I, Stelea CG, Simionescu AMA, Jehac AE, Costan VV. Silicones for Maxillofacial Prostheses and Their Modifications in Service. MATERIALS (BASEL, SWITZERLAND) 2024; 17:3297. [PMID: 38998378 PMCID: PMC11243296 DOI: 10.3390/ma17133297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2024] [Revised: 06/28/2024] [Accepted: 07/02/2024] [Indexed: 07/14/2024]
Abstract
The biomedical applications of silicones are countless due to their outstanding properties. In dentistry, silicone for maxillofacial and plastic surgery has become indispensable, from both physiological and aesthetic points of view. In this mini-review, silicone materials for dentistry and facial prostheses are discussed, focusing on their properties and alterations when exposed for long periods to different environments. A significant number of studies reported in the literature have been conducted in vitro, mimicking some of the main degradative factors which have been identified as triggers for discoloration and deterioration of the mechanical properties. Among these, in artificial aging and accelerated natural aging studies, UV radiation is considered the most important. Other weathering factors, biological contamination, and disinfection agents may have dramatic effects as well. Several general properties of silicones are described at the beginning, with a focus on biocompatibility, cross-linking mechanisms, and applications in dentistry and maxillofacial prosthetics. We discuss the ongoing cross-linking and/or possible exudation after manufacturing, which also affects the stability of the prosthesis over time, and possibly the patient. Next, the main environmental factors that affect the prostheses in service are presented, including the role of cigarettes smoke, which has been discussed very little so far. A few aspects, such as biofilm formation, its negative effects, and proposed solutions to overcome this phenomenon regarding silicones, are also described. We conclude by proposing a set of topics for future research and development based on the gaps that have been identified in the literature. Although silicones are probably irreplaceable in maxillofacial prosthetics, improvements in terms of base materials, additives, surface treatments, and maintenance are possible and necessary for long-lasting and safer prostheses.
Collapse
Affiliation(s)
- Anca Irina Gradinariu
- Department of Oral and Maxillofacial Surgery, "Grigore T. Popa" University of Medicine and Pharmacy, 16 University Street, 700511 Iasi, Romania
| | - Carmen Racles
- Department of Inorganic Polymers, "Petru Poni" Institute of Macromolecular Chemistry, 41A Grigore Ghica Voda Alley, 700487 Iasi, Romania
| | - Iuliana Stoica
- Physical Chemistry of Polymers Department, "Petru Poni" Institute of Macromolecular Chemistry, 41A Grigore Ghica Voda Alley, 700487 Iasi, Romania
| | - Carmen Gabriela Stelea
- Department of Oral and Maxillofacial Surgery, "Grigore T. Popa" University of Medicine and Pharmacy, 16 University Street, 700511 Iasi, Romania
| | - Ana-Maria Andreea Simionescu
- Department of Oral and Maxillofacial Surgery, "Grigore T. Popa" University of Medicine and Pharmacy, 16 University Street, 700511 Iasi, Romania
| | - Alina Elena Jehac
- Department of Oral and Maxillofacial Surgery, "Grigore T. Popa" University of Medicine and Pharmacy, 16 University Street, 700511 Iasi, Romania
| | - Victor Vlad Costan
- Department of Oral and Maxillofacial Surgery, "Grigore T. Popa" University of Medicine and Pharmacy, 16 University Street, 700511 Iasi, Romania
| |
Collapse
|
2
|
Makkeyah F, Elsahn NA, Bakr MM, Al Ankily M. Effect of Acidic Media on Surface Topography and Color Stability of Two Different Glass Ceramics. Eur J Dent 2024. [PMID: 38776980 DOI: 10.1055/s-0044-1786842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024] Open
Abstract
OBJECTIVE The aim of this study was to determine the effect of two acidic beverages (orange juice and H3PO4-containing fizzy drink) on the surface topography and color stability of two commonly used computer-aided design/computer-aided manufacturing (CAD/CAM) ceramic materials. MATERIALS AND METHODS Sixty samples of two CAD/CAM ceramic materials, lithium disilicate (IPS e-max CAD) and zirconia reinforced lithium silicate (Vita Suprinity), were prepared according to the manufacturer's instructions. The samples were immersed in one of three media (artificial saliva, orange juice and H3PO4-containing fizzy drink) and then stored in an incubator at 37 °C for 24 hours). Before and after immersion in different media, the surface roughness (Ra) of the samples was assessed using profilometer (JITAI8101 Surface Roughness Tester-Beijing Jitai Tech Detection Device Co. Ltd, China) and the color parameters were measured using VITA Easyshade Advance 4.01 (VITA shade, VITA made, VITA). Surface topography was observed using scanning electron microscope (SEM) and surface mineral content was compared before and after immersion. Paired sample t-test was used to determine the change in Ra before and after immersion. Two-way analysis of variance was used to determine the effect of different CAD/CAM materials and immersion media on the mean ∆Ra and mean ∆E of the studied groups. Tukey's honest significant difference posthoc test was used for multiple comparisons at a level of significance (α = 0.05). RESULTS A significant increase in Ra and a decrease in the color stability of the two investigated ceramic materials were detected after immersion in the acidic media than in artificial saliva. SEM and energy-dispersive X-ray results revealed the dissolution of the glassy matrix and the exposure of silicate crystals. CONCLUSION The surface topography and color stability of glass ceramics are affected by the pH of different acidic media.
Collapse
Affiliation(s)
- Fatma Makkeyah
- Fixed Prosthodontics Department, Faculty of Dentistry, The British University in Egypt, Cairo, Egypt
| | - Nesrine A Elsahn
- Department of Clinical Sciences, College of Dentistry, Ajman University, Ajman, United Arab Emirates
- Center of Medical and Bio-allied Health Sciences Research, Ajman University, Ajman, United Arab Emirates
- Department of Operative Dentistry, Faculty of Dentistry, Cairo University, Cairo, Egypt
| | - Mahmoud M Bakr
- General Dental Practice, School of Medicine and Dentistry, Griffith University, Gold Coast, Queensland, Australia
| | - Mahmoud Al Ankily
- Oral Biology Department, Faculty of Dentistry, The British University in Egypt, Cairo, Egypt
| |
Collapse
|
3
|
Azpiazu-Flores FX, Schricker SR, Seghi RR, Johnston WM, Leyva Del Rio D. Adhesive strength of 3 long-term resilient liners to CAD-CAM denture base polymers and heat-polymerized polymethyl methacrylate with thermocycling. J Prosthet Dent 2024; 131:494-499. [PMID: 35437173 DOI: 10.1016/j.prosdent.2022.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 03/03/2022] [Accepted: 03/04/2022] [Indexed: 10/18/2022]
Abstract
STATEMENT OF PROBLEM Computer-aided design and computer-aided manufacturing (CAD-CAM) technologies have become popular for manufacturing complete dentures. However, the adhesive strength of resilient liners to the polymers used to fabricate CAD-CAM complete dentures is unclear. PURPOSE The purpose of this in vitro study was to determine the adhesive strength of 3 long-term resilient liners to CAD-CAM denture base polymers and heat-polymerized PMMA with thermocycling. MATERIAL AND METHODS A total of 90 specimens were fabricated, 30 per group of denture base material (Lucitone 199, Ivo Base CAD, Denture Base LP). For each denture base polymer, 10 specimens were relined with 1 of 3 resilient liners (Permasoft, Mucopren Soft, Molloplast-B). Five specimens of each group were thermocycled, and the other 5 specimens were stored in distilled water. Subsequently, the adhesive strength of the specimens was assessed by tensile testing. The resulting data were analyzed by using a 3-way analysis of variance (ANOVA) (α=.05). RESULTS After thermocycling, the adhesive strengths of all the resilient liners were found to be statistically different from each other for the same denture base polymer (P≤.012). Mucopren Soft displayed a high mean ±standard deviation adhesive strength to Lucitone 199 (1.78 ±0.32 MPa), followed by Molloplast-B (1.27 ±0.21 MPa) and Permasoft (0.66 ±0.06 MPa). For Ivo Base CAD, Molloplast-B exhibited a high mean ±standard deviation adhesive strength (1.70 ±0.36 MPa), followed by Mucopren Soft (1.11 ±0.16 MPa) and Permasoft (0.53 ±0.04 MPa). Molloplast-B displayed high mean ±standard deviation adhesive strength to Denture Base LP (1.37 ±0.08 MPa), followed by Mucopren Soft (0.68 ±0.20 MPa) and Permasoft (0.32 ±0.04 MPa). The adhesive strength of the majority of resilient liners not exposed to thermocycling was statistically different from each other for the same type of denture base polymer (P<.001). The only exception was the difference between the adhesive strength of Molloplast-B and Mucopren Soft to Lucitone 199 with mean ±standard deviation values of 1.42 ±0.18 and 1.66 ±0.40 MPa, respectively, (P=.067). Without thermocycling, the mean ±standard deviation adhesive strength to Lucitone 199 of Permasoft (0.57 ±0.02 MPa) was statistically different from that of Molloplast-B and Mucopren Soft (P<.001). Molloplast-B displayed a high mean ±standard deviation adhesive strength to Ivo Base CAD (1.83 ±0.25 MPa), followed by Mucopren Soft (1.26 ±0.19 MPa) and Permasoft (0.58 ±0.08 MPa). Molloplast-B displayed a high mean ±standard deviation adhesion to Denture Base LP (1.76 ±0.23 MPa), followed by Mucopren Soft (0.88 ±0.14 MPa) and Permasoft (0.25 ±0.06 MPa). Only Molloplast-B was significantly adversely affected by thermocycling (P=.009). CONCLUSIONS Molloplast-B displayed high adhesive strength to both CAD-CAM denture base polymers regardless of the storage conditions. Mucopren Soft displayed high adhesion to Lucitone 199. Permasoft presented moderate adhesion to PMMA-based denture bases and low adhesion to DBLP. Combining Permasoft with Denture Base LP should be considered carefully and limited to short-term use. Thermocycling had a detrimental effect on the adhesive strength of Molloplast-B.
Collapse
Affiliation(s)
- Francisco X Azpiazu-Flores
- Former graduate student, Advanced Prosthodontics Program, The Ohio State University, Assistant Professor, Department of Restorative Dentistry, Dr Gerald Niznick College of Dentistry, University of Manitoba, Winnipeg, Canada.
| | - Scott R Schricker
- Associate professor, Division of Restorative and Prosthetic Dentistry, College of Dentistry, The Ohio State University, Columbus, Ohio
| | - Robert R Seghi
- Professor Emeritus, Division of Restorative and Prosthetic Dentistry, College of Dentistry, The Ohio State University, Columbus, Ohio
| | - William M Johnston
- Professor Emeritus, Division of Restorative and Prosthetic Dentistry, College of Dentistry, The Ohio State University, Columbus, Ohio
| | - Diana Leyva Del Rio
- PhD candidate, Oral Biology PhD Program, College of Dentistry, The Ohio State University, Columbus, Ohio
| |
Collapse
|
4
|
Mikulewicz M, Chojnacka K, Raszewski Z. Comparison of Mechanical Properties of Three Tissue Conditioners: An Evaluation In Vitro Study. MEDICINA (KAUNAS, LITHUANIA) 2023; 59:1359. [PMID: 37629649 PMCID: PMC10456693 DOI: 10.3390/medicina59081359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 07/14/2023] [Accepted: 07/20/2023] [Indexed: 08/27/2023]
Abstract
Introduction: Tissue conditioners have been widely used in various clinical applications in dentistry, such as treating inflamed alveolar ridges, temporarily relining partial and complete dentures, and the acquisition of functional impressions for denture fabrication. This study aimed to investigate the mechanical properties of the most prevalent tissue conditioner materials on the market, including Tissue Conditioners (TC), Visco Gel (VG), and FITT (F). Materials and Methods: The three tissue conditioners, TC, VG, and F, were assessed based on the parameters mentioned above. The following tests were performed based on the ISO 10139-1 and ISO 10139-2 requirements: Shore A hardness, denture plate adhesion, sorption, water solubility, and contraction after 1 and 3 days in water. Additional tests are described in the literature, such as ethanol content and gelling time. The tests were carried out by storing the materials in water at 37 °C for 7 days. Results: The gel times of all tested materials exceeded 5 min (TC = 300 [s], VG = 350 [s]). In vitro, phthalate-free materials exhibited higher dissolution in water after 14 days (VG = -260.78 ± 11.31 µg/mm2) compared to F (-76.12 ± 7.11 µg/mm2) and experienced faster hardening when stored in distilled water (F = 33.4 ± 0.30 Sh. A, VG = 59.2 ± 0.60 Sh. A). They also showed greater contractions. The connection of all materials to the prosthesis plate was consistent at 0.11 MPa. The highest counterbalance after 3 days was observed in TC = 3.53 ± 1.12%. Conclusions: Materials containing plasticizers that are not phthalates have worse mechanical properties than products containing these substances. Since phthalates are not allowed to be used indefinitely in medical devices, additional research is necessary, especially in vivo, to develop safe materials with superior functional properties to newer-generation alternatives. In vitro results often do not agree fully with those of in vivo outcomes.
Collapse
Affiliation(s)
- Marcin Mikulewicz
- Department of Dentofacial Orthopaedics and Orthodontics, Division of Facial Abnormalities, Medical University of Wroclaw, Krakowska 26, 50-425 Wroclaw, Poland;
| | - Katarzyna Chojnacka
- Department of Advanced Material Technologies, Faculty of Chemistry, Wroclaw University of Science and Technology, Smoluchowskiego 25, 50-372 Wroclaw, Poland;
| | | |
Collapse
|
5
|
Raszewski Z, Chojnacka K, Mikulewicz M, Alhotan A. Bioactive Glass-Enhanced Resins: A New Denture Base Material. MATERIALS (BASEL, SWITZERLAND) 2023; 16:4363. [PMID: 37374547 DOI: 10.3390/ma16124363] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 06/09/2023] [Accepted: 06/12/2023] [Indexed: 06/29/2023]
Abstract
BACKGROUND The creation of the denture base material with bioactive properties that releases ions and produces hydroxyapatite. METHODS Acrylic resins were modified by the addition of 20% of four types of bioactive glasses by mixing with powders. Samples were subjected to flexural strength (1, 60 days), sorption and solubility (7 days), and ion release at pH 4 and pH 7 for 42 days. Hydroxyapatite layer formation was measured using infrared. RESULTS Biomin F glass-containing samples release fluoride ions for a period of 42 days (pH = 4; Ca = 0.62 ± 0.09; P = 30.47 ± 4.35; Si = 22.9 ± 3.44; F = 3.1 ± 0.47 [mg/L]). The Biomin C (contained in the acrylic resin releases (pH = 4; Ca = 41.23 ± 6.19; P = 26.43 ± 3.96; Si = 33.63 ± 5.04 [mg/L]) ions for the same period of time. All samples have a flexural strength greater than 65 MPa after 60 days. CONCLUSION The addition of partially silanized bioactive glasses allows for obtaining a material that releases ions over a longer period of time. CLINICAL SIGNIFICANCE This type of material could be used as a denture base material, helping to preserve oral health by preventing the demineralization of the residual dentition through the release of appropriate ions that serve as substrates for hydroxyapatite formation.
Collapse
Affiliation(s)
| | - Katarzyna Chojnacka
- Department of Advanced Material Technologies, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland
| | - Marcin Mikulewicz
- Department of Dentofacial Orthopedics and Orthodontics, Division of Facial Abnormalities, Medical University of Wroclaw, 50-367 Wroclaw, Poland
| | - Abdulaziz Alhotan
- Department of Dental Health, College of Applied Medical Sciences, King Saud University, Riyadh P.O. Box 12372, Saudi Arabia
| |
Collapse
|
6
|
Elraggal A, R Afifi R, Alamoush RA, Raheem IA, Watts DC. Effect of acidic media on flexural strength and fatigue of CAD-CAM dental materials. Dent Mater 2023; 39:57-69. [PMID: 36496258 DOI: 10.1016/j.dental.2022.11.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 11/13/2022] [Accepted: 11/25/2022] [Indexed: 12/12/2022]
Abstract
OBJECTIVE To investigate the effect of acidic media, including beverages and gastric fluids on flexural strength and fatigue of CAD-CAM materials. METHODS Four CAD-CAM materials (high-translucency zirconia (Ceramill Zolid HT+), lithium disilicate (IPS e-max CAD), hybrid ceramic (Vita Enamic), and nanohybrid resin composite (Grandio Blocs) were prepared and immersed in one of five media (gastric HCl, white wine, Coca-Cola, orange juice, and artificial saliva) in an incubator (37 ℃, 24 h). Surface topography and roughness were obtained using a scanning electron microscope (SEM) and a stylus contact profilometer, respectively. Initial 3-point flexural strength was measured for half of the bars (n = 20/gp) using a universal testing machine (0.5 mm/min). The other bars underwent 106 cyclic fatigue loadings before measurement of residual 3-point flexural strength. Data were statistically analyzed (two-way and three-way ANOVA, Tukey's post-hoc, p < 0.05). Weibull distributions were plotted for reliability analysis. RESULTS Zirconia bars has the highest initial flexural strengths followed by lithium disilicate, while resin composite and hybrid ceramic groups had the lowest strength regardless of the erosive medium. Cyclic fatigue significantly reduced initial flexural strengths for all materials except for hybrid ceramic and resin composite. Weibull moduli were the highest for zirconia, lithium disilicate and resin composite and lowest for hybrid ceramic. SIGNIFICANCE Erosive media significantly changed surface roughness of CAD-CAM materials except for zirconia and resin composite without jeopardizing the flexural strength of the CAD-CAM materials. Despite the higher flexural strengths for zirconia and lithium disilicate, resin composite and hybrid ceramic were more resistant to cyclic fatigue.
Collapse
Affiliation(s)
- Alaaeldin Elraggal
- Conservative Dentistry Department, Faculty of Dentistry, Alexandria University, Alexandria, Egypt.
| | - Rania R Afifi
- Conservative Dentistry Department, Faculty of Dentistry, Alexandria University, Alexandria, Egypt
| | - Rasha A Alamoush
- Department of Prosthodontics, School of Dentistry, The University of Jordan, Amman, Jordan
| | - Islam Abdel Raheem
- Conservative Dentistry Department, Faculty of Dentistry, Alexandria University, Alexandria, Egypt
| | - David C Watts
- School of Medical Sciences, University of Manchester, Manchester, UK
| |
Collapse
|
7
|
An Updated Review of Salivary pH Effects on Polymethyl Methacrylate (PMMA)-Based Removable Dental Prostheses. Polymers (Basel) 2022; 14:polym14163387. [PMID: 36015644 PMCID: PMC9416770 DOI: 10.3390/polym14163387] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 08/15/2022] [Accepted: 08/16/2022] [Indexed: 01/05/2023] Open
Abstract
Salivary pH is a neglected factor that may affect the performance of removable dental prostheses (RDP). This study aimed to review literature in reference to the role of salivary pH on the performance of RDP and materials used for their fabrication. From January 1990 until December 2021, a search was done on PubMed, Scopus, and Web of Science databases using removable dental prostheses, salivary pH, PMMA, Denture base, and physical properties as keywords. Articles that met the inclusion criteria (full-length articles have investigated the effect of salivary pH on RDP materials in vitro and in vivo) were included. Out of 433 articles, 8 articles that met the inclusion criteria were included. All studies used artificial saliva with different salivary pH ranging between 3 and 14. Two articles investigated the role of salivary pH on the cytotoxicity of denture base resins and soft liner. One article studied the durability and retention of attachments, one article analyzed the performance of PEEK materials, one article researched the fatigue resistance of a denture base, one article investigated the corrosion of RPD framework cast and milled Co–Cr, one article studied the strength and clasp retention and deformation of acetal and PEEK materials, and one evaluated changes in mass and surface morphology of CAD–CAM fiber-reinforced composites for the prosthetic framework. Different salivary pH affected all included materials in this review except PEEK materials. The most adverse effect was reported with alkaline and acidic; however, the acidic showed the most deterioration effect. Salivary pH has a role in the selection of material used for RDP fabrication.
Collapse
|
8
|
Elraggal A, Afifi R, Abdelraheem I. Effect of erosive media on microhardness and fracture toughness of CAD-CAM dental materials. BMC Oral Health 2022; 22:191. [PMID: 35590294 PMCID: PMC9118722 DOI: 10.1186/s12903-022-02230-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 05/09/2022] [Indexed: 11/10/2022] Open
Abstract
Background Erosive acids might create surface flaws and deteriorate the mechanical properties of CAD-CAM materials. This invitro study aimed to investigate the effect of simulated gastric HCl and extrinsic erosive acids on surface microhardness and fracture toughness of CAD-CAM materials. Methods 400 bar-shaped specimens (17×4×2 mm3) were prepared from 4 different CAD-CAM dental materials (n = 100/group); monolithic zirconia (Ceramill Zolid HT+, Amanngirbach, Austria), lithium disilicate ceramic (IPS e.max CAD, Ivoclar Vivadent, Liechtenstein), nanohybrid resin composite (Grandio Blocs, VOCO) and polymer-infiltrated glass network (Vita Enamic, VITA Zahnfabrik). Specimens from each material type were further subdivided into 5 groups (n = 20) according to the erosive media applied (simulated gastric HCl, white wine, Coca-Cola®, orange juice, and artificial saliva that served as a control). Specimens were immersed for 24 h in an incubator at 37 ℃, then ultrasonically cleaned in distilled water and air-dried. Half of the specimens were tested for Vickers microhardness (VHN) at parameters of 500 gf for 10 s, while the rest of the specimens underwent 3-point flexure till fracture. Fractured surfaces were examined under a scanning electron microscope (SEM) for fracture toughness (KIC) calculation using the quantitative fractographic analysis method. Data collected were statistically analyzed using two-way analysis of variance (α = 0.05) after verification of data normality and homogeneity of variances. Results Erosive media created surface flaws that lowered the surface microhardness of the material and initiated the fracture pattern under different loads according to material type. The material type was a more predominant factor than erosive media that affected either the microhardness or the fracture toughness of CAD-CAM dental materials. The highest VHN and KIC values were found among Ceramill Zolid HT+ groups followed by IPS e.max CAD and Grandio Blocs regardless of the erosive media employed. Erosive media significantly reduced the VHN and KIC in Vita Enamic specimens compared to the rest of the material types. Conclusion All CAD-CAM materials used, except Vita Enamic, showed high resistance against the erosive acids indicating higher longevity of the material in patients frequently exposed to either extrinsic or intrinsic acid.
Collapse
Affiliation(s)
- Alaaeldin Elraggal
- Conservative Dentistry Department, Faculty of Dentistry, Alexandria University, Champollion street, Alexandria, Egypt.
| | - Rania Afifi
- Conservative Dentistry Department, Faculty of Dentistry, Alexandria University, Champollion street, Alexandria, Egypt
| | - Islam Abdelraheem
- Conservative Dentistry Department, Faculty of Dentistry, Alexandria University, Champollion street, Alexandria, Egypt
| |
Collapse
|
9
|
Analysis of the Statistical Comparability of the Hardness and Wear of Polymeric Materials for Orthodontic Applications. MATERIALS 2021; 14:ma14112925. [PMID: 34071606 PMCID: PMC8197806 DOI: 10.3390/ma14112925] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 05/18/2021] [Accepted: 05/25/2021] [Indexed: 12/12/2022]
Abstract
Background: Clinical success depends on the contact strength and wear resistance of medical devices made of polymer materials. The scientific goal resulted from the problem of using different methods of surface evaluation of materials used in the production of orthodontic appliances. The purpose of the work was an experimental comparative assessment of indentation hardness and scratch hardness and the sliding wear of four selected polymeric materials used in the manufacture of orthodontic appliances. Methods: Four commercial materials were compared. Shore hardness tests and a scratch test with a Rockwell indenter were performed. A sliding wear test was performed using the ball-on-disc method. Statistical PCA and correlation analyses were performed. Results: The results of scratch hardness measurements using a contact profilometer correlated with the Shore hardness to a greater extent than measurements made using an optical microscope. PCA showed that Shore hardness explains 45% of the total variance in all the results across the materials. Conclusions: The scratch hardness method allows for a more explicit ranking of orthodontic polymeric materials when measurements are made with a profilometer. The ranking of sliding wear resistance should be made separately.
Collapse
|
10
|
Domagała I, Przystupa K, Firlej M, Pieniak D, Niewczas A, Biedziak B. Bending Behaviour of Polymeric Materials Used on Biomechanics Orthodontic Appliances. MATERIALS 2020; 13:ma13235579. [PMID: 33297572 PMCID: PMC7731210 DOI: 10.3390/ma13235579] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 11/28/2020] [Accepted: 12/04/2020] [Indexed: 02/06/2023]
Abstract
This paper discusses the issues of strength and creep of polymeric materials used in orthodontic appliances. Orthodontic biomechanics is focused on the movement of individual teeth or dental groups as a result of the force applied by orthodontic appliances. Stresses in the construction of functional and biomechanical appliances is generated when using the apparatus in the oral cavity. The orthodontic appliance must maintain its shape and not be damaged during treatment so strength and creep resistance are fundamental properties. It was assumed that the clinical success of orthodontic appliances can be determined by these performance properties. The aim of the work was the experimental assessment of comparative bending strength and creep resistance of selected popular polymer materials used in the production of biomechanical orthodontic appliances. Four commercial materials manufactured by the world class producers were tested: NextDent Ortho Rigid (Vertex-Dental B.V., Soesterberg, The Netherlands) marked as "1A"; Erkocryl (ERKODENT Erich Kopp GmbH, Pfalzgrafenweiler, Germany)-"2A"; Vertex Orthoplast (Vertex Dental B.V.), blue, marked as "3A" and material with the same name as "3A" but orange, marked in the article as "4A". All the tests were carried out after aging in artificial saliva for 48 h at a temperature of 37 °C. Flexular strength and flexular modulus were made using the three point bending method according to the ISO 178 technical standard. Creep tests were carried out according to the method contained in ISO 899-2. The creep test was carried out in an artificial saliva bath at 37 °C. The creep tests showed significant differences in the strength, modulus and deformability of the tested materials. The strength reliability of the tested materials also varied. The research shows that the 2A material can be used for orthodontic applications in which long-term stresses should be lower than 20 MPa.
Collapse
Affiliation(s)
- Ivo Domagała
- Department of Facial Malformations, Poznan University of Medical Sciences, Bukowska 70, 60-812 Poznań, Poland; (I.D.); (M.F.); (B.B.)
| | - Krzysztof Przystupa
- Department of Automation, Lublin University of Technology, Nadbystrzycka 36, 20-618 Lublin, Poland
- Correspondence:
| | - Marcel Firlej
- Department of Facial Malformations, Poznan University of Medical Sciences, Bukowska 70, 60-812 Poznań, Poland; (I.D.); (M.F.); (B.B.)
| | - Daniel Pieniak
- Department of Mechanics and Machine Building, University of Economics and Innovations in Lublin, Projektowa 4, 20-209 Lublin, Poland;
| | - Agata Niewczas
- Department of Conservative Dentistry with Endodontics, Medical University of Lublin, Karmelicka 7, 20-080 Lublin, Poland;
| | - Barbara Biedziak
- Department of Facial Malformations, Poznan University of Medical Sciences, Bukowska 70, 60-812 Poznań, Poland; (I.D.); (M.F.); (B.B.)
| |
Collapse
|