Original Article
Flexural properties and impact strength of denture base resins reinforced with micronized glass flakes Ronak H. Choksi, Pranav V. Mody Department of Prosthodontics, KVG Dental College and Hospital, Sullia, Karnataka, India
Abstract
Objectives: To investigate the effect of the addition of glass flakes on physical properties of conventional heat cure denture base resins and to compare it with a high impact strength denture base resin. Materials and Methods: Test specimens were divided into Group 1 ‑ poly (methyl methacrylate) (PMMA) (Trevalon), Group 2 ‑ Trevalon HI, Group 3 ‑5% glass flake +95% PMMA (Trevalon), Group 4 ‑10% glass flake +90% PMMA (Trevalon), and Group 5 ‑20% glass flake +80% PMMA (Trevalon). For glass flake modified groups, part of PMMA (powder) was substituted with the same weight of glass flake (GF003 m) as required, to bring it to 100% powder. Flexural strength was tested using three‑point bending test and impact strength with Izod type impact tester. Results: Plain PMMA (Trevalon), showed the highest value of flexural strength followed by Trevalon HI. Trevalon HI (highly cross‑linked PMMA) group showed the highest value of impact strength. Conclusion: Flexural strength of unmodified PMMA denture base resin decreases with increase in the concentration of glass flakes. Impact strength does not show any significant change at 5% concentration of glass flakes and impact strength significantly reduces with the addition of glass flakes in 10% and 20%. Key Words: Flexural strength, glass flakes, high impact denture base resin, impact strength, poly (methyl methacrylate)
Address for correspondence: Dr. Ronak H. Choksi, Department of Prosthodontics, KVG Dental College and Hospital, Sullia ‑ 574 327, Karnataka, India. E‑mail: [email protected] Received: 11th September, 2015, Accepted: 02nd January, 2016
INTRODUCTION
The introduction of a more satisfactory plastic denture base material occurred in 1937 when Dr. Walter Wright described the results of his clinical evaluation of methyl methacrylate resin.[1] Poly (methyl methacrylate) (PMMA) has many advantages, particularly its appearance and ease of manipulation, but it has certain poor mechanical properties. Fractures may occur in use because of its unsatisfactory Access this article online Quick Response Code:
Website: www.j‑ips.org
DOI: 10.4103/0972-4052.176532
264
transverse strength, impact strength or fatigue resistance. Attempts have been made to improve the mechanical properties of acrylic resin by giving maximum bulk to the material in the regions most heavily stressed, by copolymerization and cross‑linking, reinforcement with carbon fibers.[2] The fracture of acrylic resin dentures is an unresolved problem in removable prosthodontics despite numerous attempts to determine its causes.[3] This is an open access article distributed under the terms of the Creative Commons Attribution‑NonCommercial‑ShareAlike 3.0 License, which allows others to remix, tweak, and build upon the work non‑commercially, as long as the author is credited and the new creations are licensed under the identical terms. For reprints contact: [email protected] How to cite this article: Choksi RH, Mody PV. Flexural properties and impact strength of denture base resins reinforced with micronized glass flakes. J Indian Prosthodont Soc 2016;16:264-70.
© 2016 The Journal of Indian Prosthodontic Society | Published by Wolters Kluwer - Medknow
Choksi and Mody: Effect of glass flakes on physical properties of PMMA
Vallittu and Lassila[4] studied the effect of different metal and fiber strengtheners on the fracture resistance of PMMA. Different types of commonly used metal wire and glass fiber, as well as carbon and aramid fibers, were used as strengtheners in test specimens. Each metal strengthener had a beneficial effect on the fracture resistance of the PMMA (P
Flexural properties and impact strength of denture base resins reinforced with micronized glass flakes Ronak H. Choksi, Pranav V. Mody Department of Prosthodontics, KVG Dental College and Hospital, Sullia, Karnataka, India
Abstract
Objectives: To investigate the effect of the addition of glass flakes on physical properties of conventional heat cure denture base resins and to compare it with a high impact strength denture base resin. Materials and Methods: Test specimens were divided into Group 1 ‑ poly (methyl methacrylate) (PMMA) (Trevalon), Group 2 ‑ Trevalon HI, Group 3 ‑5% glass flake +95% PMMA (Trevalon), Group 4 ‑10% glass flake +90% PMMA (Trevalon), and Group 5 ‑20% glass flake +80% PMMA (Trevalon). For glass flake modified groups, part of PMMA (powder) was substituted with the same weight of glass flake (GF003 m) as required, to bring it to 100% powder. Flexural strength was tested using three‑point bending test and impact strength with Izod type impact tester. Results: Plain PMMA (Trevalon), showed the highest value of flexural strength followed by Trevalon HI. Trevalon HI (highly cross‑linked PMMA) group showed the highest value of impact strength. Conclusion: Flexural strength of unmodified PMMA denture base resin decreases with increase in the concentration of glass flakes. Impact strength does not show any significant change at 5% concentration of glass flakes and impact strength significantly reduces with the addition of glass flakes in 10% and 20%. Key Words: Flexural strength, glass flakes, high impact denture base resin, impact strength, poly (methyl methacrylate)
Address for correspondence: Dr. Ronak H. Choksi, Department of Prosthodontics, KVG Dental College and Hospital, Sullia ‑ 574 327, Karnataka, India. E‑mail: [email protected] Received: 11th September, 2015, Accepted: 02nd January, 2016
INTRODUCTION
The introduction of a more satisfactory plastic denture base material occurred in 1937 when Dr. Walter Wright described the results of his clinical evaluation of methyl methacrylate resin.[1] Poly (methyl methacrylate) (PMMA) has many advantages, particularly its appearance and ease of manipulation, but it has certain poor mechanical properties. Fractures may occur in use because of its unsatisfactory Access this article online Quick Response Code:
Website: www.j‑ips.org
DOI: 10.4103/0972-4052.176532
264
transverse strength, impact strength or fatigue resistance. Attempts have been made to improve the mechanical properties of acrylic resin by giving maximum bulk to the material in the regions most heavily stressed, by copolymerization and cross‑linking, reinforcement with carbon fibers.[2] The fracture of acrylic resin dentures is an unresolved problem in removable prosthodontics despite numerous attempts to determine its causes.[3] This is an open access article distributed under the terms of the Creative Commons Attribution‑NonCommercial‑ShareAlike 3.0 License, which allows others to remix, tweak, and build upon the work non‑commercially, as long as the author is credited and the new creations are licensed under the identical terms. For reprints contact: [email protected] How to cite this article: Choksi RH, Mody PV. Flexural properties and impact strength of denture base resins reinforced with micronized glass flakes. J Indian Prosthodont Soc 2016;16:264-70.
© 2016 The Journal of Indian Prosthodontic Society | Published by Wolters Kluwer - Medknow
Choksi and Mody: Effect of glass flakes on physical properties of PMMA
Vallittu and Lassila[4] studied the effect of different metal and fiber strengtheners on the fracture resistance of PMMA. Different types of commonly used metal wire and glass fiber, as well as carbon and aramid fibers, were used as strengtheners in test specimens. Each metal strengthener had a beneficial effect on the fracture resistance of the PMMA (P
