Effects of boron on the mechanical properties of polymethylmethacrylate denture base material

Abstract

Purpose The objective of this study was to determine whether the addition of different types of boron (Borax, Boric Acid and Colemanite) to polymethyl methacrylate denture base resin would improve flexural and impact strengths, and surface hardness of polymethyl methacrylate. Materials and Methods Borax, Boric acid, Colemanite were added to heat polymerized polymethyl methacrylate specimens were prepared for flexural strength (65x10x2.5 mm), impact strength (50x6x4 mm), and hardness (20x6x4 mm) tests according to the manufacturers' instructions (n=10). To determine flexural strength of the specimens, they were loaded until failure on a universal testing machine using a three point bending test. Specimens were subjected to the Charpy impact test machine. Hardness of the specimens was measured with an analog shoremeter Shore D. The data were analyzed with Kruskal-Wallis and Mann-Whitney U tests (α=0.05). Results The highest mean flexural strength value was seen in 3% Borax group and followed by 1% Colemanite group. In addition, the highest mean impact strength value was recorded in 1% Colemanite group, and differences between 1% Colemanite group and control group were found to be statistically significant (p=0,001). Furthermore, there was significant difference in hardness between control group and all other groups (p<0.001). Conclusion The addition of 1% Colemanite to polymethyl methacrylate improved the mechanical properties of PMMA.

Influence of Reinforcing Agents on the Mechanical Properties of Denture Base Resin: A Systematic Review

“…Low filler loading might homogenously distribute within the denture base resin, fill the void/space of the inter-polymeric chain, and limit their movement. Similar findings were suggested by Gad et al [30], Balos et al [47], Demir et al [53], Zhang et al [55], and Naji et al [56]. However, decreased microhardness at elevated loading might suggest that the resin is not adequately reinforced or that the EM of a reinforcing agent is lower than that of the resin itself.…”

“…Glass fibers and other types of polymeric fibers were of also interest to investigators [31,32,34,[37][38][39][40][41]51,52]. There was less of an inclination towards the use of minerals such as mica, borax, boric acid, and colemanite as reinforcing agents in denture base resin [43,53]. The use of treated reinforcing agents was also found in most of the included studies.…”

“…The trend of evaluating the fractural strength (FS) and fracture toughness (FT) were the common testing parameters. However, the investigators were also interested to see the reinforcing effect of fillers on surface hardness (SH) [30,43,46,47,[53][54][55][56]. On the contrary, the IS of the reinforced denture base resin was evaluated in very few studies [45,48,53].…”

“…However, the investigators were also interested to see the reinforcing effect of fillers on surface hardness (SH) [30,43,46,47,[53][54][55][56]. On the contrary, the IS of the reinforced denture base resin was evaluated in very few studies [45,48,53]. While the compressive strength [50] and the fracture resistance [40], each as testing parameters, were used in a single study.…”

“…Similarly, fiber length and its adhesion with the resin matrix are crucial for the flexural properties of composite material [52]. Nonetheless, reinforcing agents in denture base resin improves the FS, however, the efficacy hinges on several factors, including the material type, form, % of loading, surface treatment, and orientation of the reinforcing agent [53][54][55][56].…”