Effects of Neem Powder on Water Sorption and Solubility Characteristics of PMMA Denture Base Resin
DOI:
https://doi.org/10.68050/JAMS.2026.745Keywords:
denture base resin, PMMA, neem, Azadirachta indica, water sorption, natural additiveAbstract
This study was conducted to determine the effect of neem (Azadirachta indica) leaf powder on the water sorption, water solubility and solvent resistance of heat-polymerised poly(methyl methacrylate) (PMMA) denture base resin. Neem leaves were sun-dried, pulverised and sieved to below 53 µm, and the powder was blended into PMMA polymer at 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 g per 25 g of polymer (2 to 12 % of the polymer mass). Specimens were heat-polymerised alongside an unmodified control. Water absorption was determined as the percentage mass gain after 7 days of immersion in distilled water at 37 °C, and solubility as the percentage mass lost after immersion and reconditioning to constant mass, on separate specimens. Resistance to water, acetone, ethanol, methanol, toluene and tetrahydrofuran was screened qualitatively. One specimen per formulation was tested for each property, and trends with loading were described by linear regression. All neem-modified specimens absorbed more water than the control (1.09 % to 1.68 %, compared with 0.21 %), although the control value was unusually low, so the size of the difference is uncertain. Absorption tended to increase with loading (R² = 0.68), but this trend depended largely on the specimen with the highest loading and was not confirmed by a rank-based test. Solubility ranged from 0.33 % to 1.43 %, compared with 0.58 % for the control, and showed no relationship with loading (R² = 0.10). All formulations, like the control, resisted water and the four organic solvents and dissolved only in tetrahydrofuran. Neem powder appears to increase the water uptake of PMMA denture base resin, and this should be confirmed with replicated, standardised specimens.
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