RESUMO
Objective: This laboratory study evaluated the effect of Salvadora persica (S. persica) root extracts and Chlorhexidine Digluconate (CHX) on the antibacterial and surface hardness properties of glass ionomer cement (GIC). Methods: The in vitro experimental study was conducted at the Baqai Institute of Pharmaceutical Sciences of Baqai Medical University, Karachi, Pakistan, from October 2022 to March 2023. There were a total four experimental groups. The first group consisted of ethanol extract (GIC-SPEE) and second group consisted of hexane extract as (GIC-SPHE) both prepared from Salvadora persica root respectively, and mixed with liquid of GIC separately. The third group comprised chlorhexidine (GIC-CHX) that was also mixing into liquid portion of GIC and the last group was Control i.e. (cGIC). The GIC samples were prepared by using stainless steel metallic moulds with dimension (5mm x 2mm), following the manufacturer guidelines. Antibacterial activity against Streptococcus mutans was done by disc diffusion test (DDT), and surface hardness test was done by Vickers hardness tester. Statistical analysis was performed using One-Way ANOVA and Tukey's post hoc tests (p<0.05). Results: The antibacterial activity against S. mutans reported that the maximum zone of inhibition was obtained at 3 wt% by the GIC-SPEE, when compared with other experimental groups. For surface hardness, the highest mean and standard deviation and significant findings was reported by the group GIC-SPEE. Conclusions: Considering the outcome of this in vitro study, it can be concluded that the addition of 3 wt% GIC-SPEE increased the surface hardness and antibacterial activity against Streptococcus mutans.
RESUMO
Objective: This study aimed to improve the mechanical properties of denture base material using various concentrations of natural biopolymer, i.e., Gum Arabic (GA). Methods: This experimental study was conducted at the Dental Health Department of the College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia from May 2022 to July 2022. After obtaining exemption from the institutional review board, the powdered GA was added in ratios of weight 5, 10, and 20% to PMMA heat-cured acrylic powder to produce bar-shaped samples (65 × 10 × 30 mm3 in dimensions). While the control group was prepared as such. Micro hardness (n=10/group) and fracture toughness (n=10/group) were evaluated. One-way analysis of variance method was used to statistically analyze the results (p<0.05) using SPSS version 23. Results: Significant differences were observed for micro hardness (p<0.001) and fracture toughness (p=0.007) between the means of the different study groups. The control group exhibited the highest micro hardness (22.5±0.6 VHN) and fracture toughness (1.25±0.11 MPa.m1/2) value among the study groups. While 20 wt. % GA and 10 wt. % GA groups showed the lowest micro hardness and fracture toughness values, respectively. Conclusions: GA powder might not be an appropriate reinforcing material for denture base or the higher filler loading of GA in denture base acrylic might be detrimental to the mechanical properties.
RESUMO
Objective: This laboratory study determined the surface, mechanical and chemical properties of polymethyl methacrylate (PMMA) denture resin reinforced with micron-sized Gum Arabic (GA) powder in different weight ratios. Methods: This laboratory study was conducted at the Dental Health Department of the College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia from November 2022 to February 2023. Three experimental denture resins were prepared by incorporating GA powder in heat-polymerized PMMA powder using different wt.% (5, 10, and 20 wt.%). While pristine PMMA served as the control group. A total of ten bar-shaped specimens with dimensions of 65 mm × 10 mm × 3.5 mm were prepared for each study group. The surface properties (micro CT and SEM evaluation), mechanical properties (Nanohardness, elastic modulus and flexural strength) and chemical properties (FTIR) were conducted. The data were statistically analyzed using the one-way analysis of variance and Tukey's post hoc tests (p<0.05). Results: The surface and bulk properties of experimental GA-reinforced PMMA resin materials deteriorated while the mechanical properties were also negatively altered using GA-based PMMA denture resin. A linear correlation was observed between weak mechanical properties and increasing wt.% of GA in denture resin. Conclusions: The incorporation of GA powder in denture resin might not be a viable option. The surface and mechanical properties of experimental PMMA composites were adversely affected compared to the control group.