D M Andrade Neto1, E V Carvalho1, E A Rodrigues2, V P Feitosa3, S Sauro4, G Mele5, L Carbone6, S E Mazzetto1, L K Rodrigues2, P B A Fechine7. 1. Group of Chemistry of Advanced Materials (GQMAT) - Department of Analytical Chemistry and Physic-chemistry, Federal University of Ceará - UFC, Campus do Pici, CP 12100, Zip Code 60451-970, Fortaleza, Brazil. 2. Post-Graduate Program in Dentistry - Department of Restorative Dentistry, Federal University of Ceará, Fortaleza, Brazil. 3. Post-Graduate Program in Dentistry - Department of Restorative Dentistry, Federal University of Ceará, Fortaleza, Brazil. Electronic address: victorpfeitosa@hotmail.com. 4. Post-Graduate Program in Dentistry - Department of Restorative Dentistry, Federal University of Ceará, Fortaleza, Brazil; Dental Biomaterials - Departmento de Odontologia, Facultad de Ciencias de la Salud, CEU-Cardenal Herrera University, Alfara del Patriarca, 46115 Valencia, Spain. 5. Dipartimento di Ingegneria dell'Innovazione, Università del Salento, Via Arnesano, 73100 Lecce, Italy. 6. CNR-IPCF UOS Pisa, Via G. Moruzzi 1 - 56124 Pisa, Italy. 7. Group of Chemistry of Advanced Materials (GQMAT) - Department of Analytical Chemistry and Physic-chemistry, Federal University of Ceará - UFC, Campus do Pici, CP 12100, Zip Code 60451-970, Fortaleza, Brazil. Electronic address: fechine@ufc.br.
Abstract
OBJECTIVES: Enamel resin infiltrants are biomaterials able to treat enamel caries at early stages. Nevertheless, they cannot prevent further demineralization of mineral-depleted enamel. Therefore, the aim of this work was to synthesize and incorporate specific hydroxyapatite nanoparticles (HAps) into the resin infiltrant to overcome this issue. METHODS: HAps were prepared using a hydrothermal method (0h, 2h and 5h). The crystallinity, crystallite size and morphology of the nanoparticles were characterized through XRD, FT-IR and TEM. HAps were then incorporated (10wt%) into a light-curing co-monomer resin blend (control) to create different resin-based enamel infiltrants (HAp-0h, HAp-2h and HAp-5h), whose degree of conversion (DC) was assessed by FT-IR. Enamel caries lesions were first artificially created in extracted human molars and infiltrated using the tested resin infiltrants. Specimens were submitted to pH-cycling to simulate recurrent caries. Knoop microhardness of resin-infiltrated underlying and surrounding enamel was analyzed before and after pH challenge. RESULTS: Whilst HAp-0h resulted amorphous, HAp-2h and HAp-5h presented nanorod morphology and higher crystallinity. Resin infiltration doped with HAp-2h and HAp-5h caused higher enamel resistance against demineralization compared to control HAp-free and HAp-0h infiltration. The inclusion of more crystalline HAp nanorods (HAp-2h and HAp-5h) increased significantly (p<0.05) the DC. SIGNIFICANCE: Incorporation of more crystalline HAp nanorods into enamel resin infiltrants may be a feasible method to improve the overall performance in the prevention of recurrent demineralization (e.g. caries lesion) in resin-infiltrated enamel.
OBJECTIVES: Enamel resin infiltrants are biomaterials able to treat enamel caries at early stages. Nevertheless, they cannot prevent further demineralization of mineral-depleted enamel. Therefore, the aim of this work was to synthesize and incorporate specific hydroxyapatite nanoparticles (HAps) into the resin infiltrant to overcome this issue. METHODS: HAps were prepared using a hydrothermal method (0h, 2h and 5h). The crystallinity, crystallite size and morphology of the nanoparticles were characterized through XRD, FT-IR and TEM. HAps were then incorporated (10wt%) into a light-curing co-monomer resin blend (control) to create different resin-based enamel infiltrants (HAp-0h, HAp-2h and HAp-5h), whose degree of conversion (DC) was assessed by FT-IR. Enamel caries lesions were first artificially created in extracted human molars and infiltrated using the tested resin infiltrants. Specimens were submitted to pH-cycling to simulate recurrent caries. Knoop microhardness of resin-infiltrated underlying and surrounding enamel was analyzed before and after pH challenge. RESULTS: Whilst HAp-0h resulted amorphous, HAp-2h and HAp-5h presented nanorod morphology and higher crystallinity. Resin infiltration doped with HAp-2h and HAp-5h caused higher enamel resistance against demineralization compared to control HAp-free and HAp-0h infiltration. The inclusion of more crystalline HAp nanorods (HAp-2h and HAp-5h) increased significantly (p<0.05) the DC. SIGNIFICANCE: Incorporation of more crystalline HAp nanorods into enamel resin infiltrants may be a feasible method to improve the overall performance in the prevention of recurrent demineralization (e.g. caries lesion) in resin-infiltrated enamel.
Authors: Fahad Saleem Ahmed Khan; N M Mubarak; Mohammad Khalid; Rashmi Walvekar; E C Abdullah; Awais Ahmad; Rama Rao Karri; Harshini Pakalapati Journal: Sci Rep Date: 2021-01-12 Impact factor: 4.379