Resin-based dental materials containing 3-aminopropyltriethoxysilane modified halloysite-clay nanotubes for extended drug delivery. Issue 3 (March 2021)

• Record Type: Journal Article
• Authors: Karczewski, Ashley; Kalagi, Sara; Viana, Ítallo Emídio Lira; Martins, Victor Mota; Duarte, Simone; Gregory, Richard L.; P. Youngblood, Jeffrey; Platt, Jeffrey A.; Feitosa, Sabrina
• Is Part Of: Dental materials. Volume 37:Issue 3(2021)
• Page Start: 508
• Page End: 515
• Publication Date: 2021-03
• Subjects: Chlorhexidine -- Inhibition zone -- Nanotubes -- Resin-based materials -- Silanization; Dentistry -- Periodicals; Dental materials -- Periodicals; 617.695
• DOI: 10.1016/j.dental.2020.12.011
• Languages: English
• ISSNs: 0109-5641

Abstract

Highlights: Silanization of halloysite nanotubes was not detrimental to the mechanical properties of the resin-based material. Silanization of halloysite nanotubes improved the antimicrobial activity of the chlorhexidine. Silanization of nanotubes before encapsulation with chlorhexidine is a promising technique. Abstract: Objective: To synthesize and characterize a novel resin-based dental material containing 3-aminopropyltriethoxysilane (APTES) surface-modified halloysite-clay nanotubes (HNTs) for long-term delivery of guest molecules. Methods: The optimal concentrations of HNT (10, 15, 20 wt.%) and silane (0, 2, 4 vol.%sil) to be incorporated into the resin-based materials were determined (15 wt.%HNT, 4 vol.%sil) after assessment of the mechanical properties (DC%, degree of conversion; FS, flexural strength; FM, flexural modulus; and UTS, ultimate tensile strength). The HNTsil-powder was loaded with chlorhexidine (CHX) to evaluate the effect of the silanization on drug release. Resin-discs were prepared for the following groups: RES (resin), HNT (resin+15 wt.%HNT), HNTsil (resin+15 wt.%HNT silanized), HNT-CHX (resin+15 wt.%HNT loaded with chlorhexidine), HNTsil-CHX (resin+15 wt.%HNTsil-CHX), and 0.2 vol.%CHX (resin+0.2 vol.%CHX solution). Specimens were stored in water for 1, 3, 5, 10, and 15 days at 37 °C. Aliquots from each time point and the final 15-day specimens were evaluated for the zone of inhibition (ZOI) against Streptococcus mutans . CHX release was analyzed using spectrophotometry at absorbance of 300 nm. Data were statistically analyzed ( α = 0.05). Results: All materials presented similar DC%. Reduced FS but increased FM was detected for 20 wt.%HNT–4%APTES. Groups with 15 wt.% and 20 wt.%HNT with/without APTES presented higher values of UTS. Agar diffusion data indicates that the HNTsil-CHX had a greater ZOI than all other groups over 15 days. HNTsil-CHX had the highest absorbance for day 1 but presented similar values to other groups every time point after. Significance: Silanization of nanotubes followed by encapsulation of chlorhexidine is a promising technique for long-term delivery of guest molecules.