Physicomechanical and antibacterial properties of experimental resin‐based dental sealants modified with nylon‐6 and chitosan nanofibers

Abstract

This study aimed to develop and evaluate resin-based experimental dental sealants containing electrospun nylon-6 (N6) and chitosan (CH) fibers in an attempt to improve the physicomechanical properties and provide an antibacterial protective effect, respectively. Electrospun N6 and CH mats were immersed into a resin mixture, light-cured, and then cryomilled to obtain micron-sized resin-modified fiber particles. Different levels of the novel cryomilled particles (i.e. 1, 2.5, and 5% relative to the resin mixture, % by weight) were used to prepare the N6- and CH-containing sealants. A commercial sealant and the experimental resin mixture (unfilled) were used as controls. Flexural strength (FS), Vickers microhardness (VH), and agar diffusion tests were performed. The data were analyzed at the 5% significance level. No significant difference in fiber diameter of N6 (503 ± 31 nm) and CH (595 ± 38 nm) was observed. Upon cryomilling, the resin-modified CH and N6 mats led to the formation of irregularly-shaped particles, with an average diameter of 14.24 µm and 15.87 µm, respectively. CH-5% had significantly higher FS (115.3 ± 1.3 MPa) than all the other groups. CH-1% had significantly higher hardness values (38.3 ± 0.3 VHN) than all the other groups. Collectively, the results indicated that CH-containing sealants presented the highest FS and hardness; however, none of the CH-containing sealants displayed antimicrobial properties.

Effect of methacrylated chitosan incorporated in experimental composite and adhesive on mechanical properties and biofilm formation

“…The antimicrobial effects of unmodified chitosan in adhesives and glass‐ionomer cement, as well as the mechanical properties of the modified materials, have been explored . Chitosan nanofibers incorporated into sealants improved the mechanical properties, but the materials did not display any antimicrobial properties . Donati et al .…”

Antibacterial, chemical and physical properties of sealants with polyhexamethylene guanidine hydrochloride

“…Bisphenol A glycol dimethacrylate (BisGMA, Aldrich Chemical Company, St. Louis, Missouri, USA) at 60 wt.% and triethylene glycol dimethacrylate (TEGDMA, Aldrich Chemical Company, St. Louis, USA) at 40 wt.% were hand-mixed for 5 min, sonicated for 180 s and hand-mixed again for 5 min 25 . A photoinitiator /co-initiator system composed by Camphorquinone (CQ, Aldrich Chemical Company, St. Louis, USA) and ethyl 4-dimethylaminobenzoate (EDAB, Aldrich Chemical Company, St. Louis, USA) added at 1 mol%, according to BisGMA and TEGDMA moles 13 . Polyhexamethylene guanidine hydrochloride (PHMGH), Figure 1, was incorporated at 0.5 (G 0.5% ), 1 (G 1% ), and 2 (G 2% ) wt.% in the resin sealant for test groups and one group, without PHMGH, was used as control (G CTRL ).…”

“…11 To overcome this issue, the incorporation of fillers in resin sealants have been used to improve the acid-and caries-resistance of dental tissue. Sodium monofluorophosphate, 12 nylon-6 and chitosan, 13 fluoroboroaluminosilicate glass, 14 and Bioglass 45S5 15,16 were already tested. In addition, enamel pre-treatments, such as 45S5 bioactive glass airabrasion, done before sealant application, have been evaluated, improving enamel etchability and reducing microleakage.…”

Chitosan Biomaterials for Current and Potential Dental Applications

“…Chitosan has emerged as a potential material for biodental applications corresponding to its unique properties such as bioactivity [ 50 , 51 ], antimicrobial [ 41 , 42 , 52 ], biocompatibility [ 14 , 53 , 54 ] and compatibility to blend with other materials [ 1 , 55 , 56 ]. The chitosan-based materials have been explored extensively for a wide range of dental applications ( Figure 4 .)…”