Flexural Strength and Radiodensity of Different Barium Sulfate-Containing Polymethyl Methacrylate Provisional Restorative Materials.

Abstract

Provisional restoration fabricated from polymethyl methacrylate (PMMA) faces radiographic clarification due to its radiolucency. This study determined the appropriate radiodensity and strength of auto-polymerized PMMA (P) upon adding barium sulfate (B) at different concentrations.A total of 90 specimens (length × width × height = 30 × 12.5 × 2.0 mm) were prepared from P containing B at different ratios (volume %B): 5P-0B (0%), 4P-1B (20%), 3P-1B (25%), 2P-1B (33.3%), 1P-1B (50%), and 1P-2B (66.7%) (n = 15/group). Specimens were CBCT (cone-beam computed tomography)-scanned and their radiodensity measured in Hounsfield units (HU). A three-point bending test was used to determine flexural strength (σ).ANOVA (analysis of variance) and Tukey tests were used for analyzing significant differences in radiodensity and σ among groups (α = 0.05). The correlation coefficient (R) between radiodensity and σ was determined with the Spearman test.Radiodensity (HU) was intense in 1P-2B (1,080.28 ± 119.8) and softest in 5P-0B (-283.3 ± 73.8), whereas σ (MPa) was highest in 5P-0B (60.3 ± 15.2) and lowest in 1P-2B (15.9 ± 3.4). Significant differences in radiodensity among groups (p < 0.05) were indicated, except between 4P-1B/3P-1B/2P-1B and 2P-1B/1P-1B. Significant differences in σ among groups (p < 0.05) were indicated, except between 3P-1B/2P-1B and 1P-1B/1P-2B. Increasing amount of B intensified radiodensity, but diminished σ, with extreme negative correlation (R = -0.83).Radiodensity and σ were influenced by the amount of B addition. Raising B intensifies radiopacity but lessens σ. Adding B up to 25% provides adequate radiopacity and strength for provisional restorations for use in high-stress areas. However, adding B ≥33.3% provides better radiographic visibility but minimized strength, suggesting restorations in less-stress areas or other appliances, such as radiographic and surgical guides.