Comparison and Evaluation of Flexural Strength of Heat Polymerized Acrylic Resin After Repair With Zirconia Oxide and Aluminium Oxide Reinforced Autopolymerizing Acrylic Resin With Two Different Repair Designs and With and Without Surface Treatment - An Invitro Study

Abstract

Aim:The aim of this study was to evaluate and compare flexural strength of repaired heat polymerized acrylic resin with zirconia oxide and aluminium oxide nanoparticles incorporated autopolymerized acrylic resin and to evaluate effect of butt and bevel joint design of repair with and without chemical surface treatment. Materials and Method: A total of 165 heat cure acrylic resin specimens were fabricated and divided into 3 main groups. Group A had 15 intact specimens whereas group B and group C were further divided into 5 subgroups depending on repair material, repair design and chemical surface treatment used. Each subgroup had 15 specimens. 7wt% zirconia oxide and 2wt% aluminium oxide nanoparticles used as reinforcement material into autopolymerized acrylic resin and compared with unreinforced autopolymerized resin used for repair. Butt and bevel joint designs and ethyl acetate as a chemical surface treatment used for repair of acrylic specimens. The specimens were subjected to flexural strength in a universal testing machine until specimens fractured and load values were recorded. Flexural strength wascalculated in MPa (Megapascal) and analysed using Independent t test, One Way ANOVA and Post hoc Tukey's test. Results: The flexural strength values obtained were highly significant for nanoparticles reinforced groups than unreinforced autopolymerized resin. Also zirconia oxide nanoparticles showed higher values than aluminium oxide nanoparticles. Similarly, repair with bevel joint design and with chemical surface treatment with ethyl acetate proved to be better. Conclusion:Under the conditions of this study, 7wt% zirconia oxide and 2wt% aluminium oxide reinforced autopolymerized resin with bevel joint design and chemical surface treatment with ethyl acetate can be recommended for acrylic repair.

Effect of repair and thermal cycling on the flexural strength of denture base materials fabricated from different methods

“…1,2 Being cheap, biocompatible, easy to apply and repair, stable in the oral environment, satisfactory aesthetic, and mechanical properties are suitable and can be counted as advantages of PMMA. 2,3,4 Besides these advantages, PMMA has low dimensional stability and low impact, and flexural strength. Low dimensional stability leads to crack propagation and the formation of microporosities which may cause prosthesis fracture in the oral environment under different thermal temperatures.…”

“…1,3 These fractures can happen inside the patient's mouth fatigue failure in the course of service or outside the patient's mouth because of an accidental fall. 1,4 Repeated denture flexure by occlusal forces causes stress accumulation and fatigue failure. 1,4,5 Today, the most common reason for the failure of the removable prosthesis is fracturing of the denture bases.…”

“…1,4 Repeated denture flexure by occlusal forces causes stress accumulation and fatigue failure. 1,4,5 Today, the most common reason for the failure of the removable prosthesis is fracturing of the denture bases. 1 Denture repair is preferred to new denture fabrication because the repair is less time-consuming and decreases the cost.…”

“…1 Denture repair is preferred to new denture fabrication because the repair is less time-consuming and decreases the cost. 4 Denture repair material should be the same color as the denture base, easy and quickly perform, and improves the strength to prevent further fracture. 4,5,6 Auto-polymerized acrylic resin, visible light polymerized acrylic resin, heat polymerized acrylic resin, and microwave polymerized acrylic resins have been used to repair fractured denture bases.…”

“…4 Denture repair material should be the same color as the denture base, easy and quickly perform, and improves the strength to prevent further fracture. 4,5,6 Auto-polymerized acrylic resin, visible light polymerized acrylic resin, heat polymerized acrylic resin, and microwave polymerized acrylic resins have been used to repair fractured denture bases. 4,7 Auto-polymerized acrylic resin is used for denture base repairs commonly because of ease of manipulation, being less timeconsuming and economic.…”