Abstract

Objective: To determine whether alkali-treated bamboo husk fillers at 4% and 8% (wt%) increase the flexural strength of heat-cured PMMA versus unfilled PMMA, and to assess how artificial aging in saliva (12h, 24h, 7d, 1mo) affects this outcome.
Methodology: This experimental study was conducted at de’ Montmorency College of Dentistry and the University of Lahore from September 2021 to December 2024. Bamboo husks were treated with 5% sodium hydroxide (NaOH) to enhance cellulose content, followed by drying and sieving. PMMA and bamboo husk fillers (4% and 8% by weight) were mixed and cured using a water bath method. A total of 110 rectangular specimens were fabricated and tested using a three-point bending test for flexural strength. Samples were artificially aged in artificial saliva at 37°C for 12, 24, 7 days, and 1 month. The data were analyzed using SPSS, and a p≤0.05 was considered statistically significant.
Results: The addition of bamboo husk fillers significantly improved the flexural strength of PMMA. The highest flexural strength was observed in the 8% bamboo filler group (76.10±0.98 MPa), which was significantly greater than both the control group (68.88±1.80 MPa) and the 4% filler group (70.94±1.30 MPa) (p=0.001). Aging further enhanced the strength, with Group C (8% bamboo filler) outperforming Group B (p=0.001) at 7 days and one month.
Conclusion: Alkali-treated bamboo husk fillers significantly improved the flexural strength of heat-cured PMMA, particularly at higher concentrations, offering both immediate and long-term reinforcement benefits.

Key words: Aging, alkali treatment, bamboo husk fillers, fiber reinforcement. flexural strength, PMMA.