Abstract
Background Toothbrush manufacturers commonly use bristle materials such as nylon, polybutylene terephthalate, polypropylene, polyethylene terephthalate, boar hair, bamboo, carbon fiber, silicone, polylactic acid, or their modifications such as Curen(®). Nylon filaments have long been demonstrated to be durable and are widely used, but not much is known regarding the performance of Curen(®) filaments compared to nylon filaments. This in vitro study compared the stiffness, abrasion potential, abrasion resistance, and bristle surface changes of Curen(®) and nylon filaments. Methodology Ten specimens (five dry and five wet) each of Curaprox CS5460 toothbrushes featuring Curen(®) filaments and those with nylon filaments were subjected to tensile strength and force-displacement analyses. Brushing simulation (1,000, 2,000, 3,000, and 5,000 cycles) was conducted using six freshly extracted central incisors (three specimens each for the Curen(®) and nylon filament groups). Pre- and post-brushing simulation parameters included filament abrasion potential (atomic force microscopy of extracted tooth surface), filament abrasion resistance (field emission scanning electron microscopy), and bristle surface changes (stereomicroscopy and micro- and nano-computed tomography). Results Curen(®) filaments exhibited lower tensile strengths (41.69 MPa [dry] and 35.18 MPa [wet]) than nylon filaments (321.56 MPa [dry] and 325.44 MPa [wet]), indicating that Curen(®) filaments have lower abrasion potential (87% [dry] and 89% [wet]) and cause less mechanical wear of enamel, thereby resulting in a gentler cleaning experience compared to nylon filaments. Furthermore, the enamel surface roughness in the crown region decreased by 19.4% with the use of the Curen(®) filaments, whereas it increased by 92.3% with the use of nylon filaments, indicating that Curen(®) filaments are 72.84% less abrasive to enamel than nylon filaments. After 5,000 cycles of brushing simulation, Curen(®) filaments showed 30% less splaying than nylon filaments, highlighting the longevity of Curen(®) filaments up to six months of tooth brushing, which is twice the longevity of nylon filaments. There was a minimal decrease in height (12.0 mm to 11.95 mm, -0.4% change), an increase in top diameter (2.157 mm to 2.390 mm, 10.8% change), and a rise in base diameter (1.784 mm to 2.035 mm, 14% change) in the Curen(®) filaments group. Taken together, these results indicate that Curen(®) filaments are superior to nylon filaments as teeth-cleansing agents. Conclusion The findings of this in vitro analysis demonstrate the lower tensile strength and lesser abrasion potential of Curen(®) filaments when compared with nylon filaments. Thus, Curen(®) filaments cause fewer microscratches and abrasion of enamel when compared with nylon filaments, occurring due to day-to-day mechanical wear because of improper brushing technique. Furthermore, the lower tensile strength of Curen(®) filaments provides greater flexibility, facilitating more effective cleaning of hard-to-reach areas compared to nylon filaments. Additionally, the lesser splaying of Curen(®) filaments highlights their longevity, demonstrating that Curen(®) filaments last twice as long as nylon filaments under regular brushing conditions. Based on these advantages, toothbrushes with Curen(®) filaments should be a preferred choice over nylon filaments.