Ashley Karczewski1, Sara Kalagi2, Ítallo Emídio Lira Viana3, Victor Mota Martins4, Simone Duarte5, Richard L Gregory6, Jeffrey P Youngblood7, Jeffrey A Platt8, Sabrina Feitosa9. 1. Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry (IUSD), Indianapolis, IN 46202, USA. Electronic address: aekarcze@iu.edu. 2. Department of Cariology, Operative Dentistry and Dental Public Health, Indiana University School of Dentistry (IUSD), Indianapolis, IN 46202, USA; Department of Restorative and Prosthetic Dental Sciences, College of Dentistry, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia. Electronic address: Kalajis@ksau-hs.edu.sa. 3. Department of Restorative Dentistry, School of Dentistry, University of São Paulo, 05508-000 SP, Brazil. Electronic address: italloviana@usp.br. 4. Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry (IUSD), Indianapolis, IN 46202, USA; Department of Operative Dentistry and Dental Materials, Federal University of Uberlandia, UFU, Minas Gerais, Brazil; Department of Operative Dentistry, School of Dentistry, Faculdade Patos de Minas (FPM), Patos de Minas, Minas Gerais, 38700-001, Brazil. Electronic address: victor.martins@faculdadepatosdeminas.edu.br. 5. Department of Cariology, Operative Dentistry and Dental Public Health, Indiana University School of Dentistry (IUSD), Indianapolis, IN 46202, USA. Electronic address: siduarte@iu.edu. 6. Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry (IUSD), Indianapolis, IN 46202, USA. Electronic address: rgregory@iu.edu. 7. School of Materials Engineering, Purdue University, 701 West Stadium Ave., West Lafayette, IN 47907-2045, USA. Electronic address: jpyoungb@purdue.edu. 8. Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry (IUSD), Indianapolis, IN 46202, USA. Electronic address: jplatt2@iu.edu. 9. Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry (IUSD), Indianapolis, IN 46202, USA. Electronic address: sfeitosa@iu.edu.
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.
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.
Authors: B Rabindran Jermy; Vijaya Ravinayagam; D Almohazey; W A Alamoudi; H Dafalla; Sultan Akhtar; Gazali Tanimu Journal: Appl Clay Sci Date: 2021-11-09 Impact factor: 5.467