Long-term dentin remineralization by poly(amido amine) and rechargeable calcium phosphate nanocomposite after fluid challenges. Issue 4 (April 2018)

• Record Type: Journal Article
• Authors: Liang, Kunneng; Xiao, Shimeng; Wu, Junling; Li, Jiyao; Weir, Michael D.; Cheng, Lei; Reynolds, Mark A.; Zhou, Xuedong; Xu, Hockin H.K.
• Is Part Of: Dental materials. Volume 34:Issue 4(2018)
• Page Start: 607
• Page End: 618
• Publication Date: 2018-04
• Subjects: Long-term remineralization -- Dentin -- Poly(amido amine) -- NACP nanocomposite -- Ion recharge -- Acid challenge; Dentistry -- Periodicals; Dental materials -- Periodicals; 617.695
• DOI: 10.1016/j.dental.2018.01.001
• Languages: English
• ISSNs: 0109-5641

Abstract

Abstract: Objective: Previous studies investigated short-term dentin remineralization; studies on long-term dentin remineralization after fluid challenges mimicking fluids in oral environment are lacking. The objective of this study was to develop a long-term remineralization method to via poly(amido amine) (PAMAM) and rechargeable composite containing nanoparticles of amorphous calcium phosphate (NACP) after fluid challenges for the first time. Methods: NACP composite was immersed at pH 4 to exhaust its calcium (Ca) and phosphate (P) ions, and then recharged with Ca and P ions, to test the remineralization of the exhausted and recharged NACP composite. Dentin was acid-etched with 37% phosphoric acid. Four groups were prepared: (1) dentin control, (2) dentin with PAMAM, (3) dentin with the recharged NACP composite, and (4) dentin with PAMAM plus recharged NACP composite. PAMAM-coated dentin was immersed in phosphate-buffered saline with shaking for 72 days, because there is fluid flow in the mouth which could potentially detach the PAMAM from dentin. Specimens were treated with a cyclic artificial saliva/lactic acid regimen for 35 days. Results: After 72 days of immersion plus shaking, the PAMAM still successfully fulfilled its mineralization nucleation. The recharged NACP composite still provided acid-neutralization and ion re-release, which did not decrease with increasing the number of recharge cycles. The immersed-PAMAM plus NACP achieved complete dentin remineralization and restored the hardness to that of healthy dentin. Signifiance: In conclusion, superior long-term remineralization of the PAMAM plus NACP method was demonstrated for the first time. The immersed-PAMAM plus recharged NACP completely remineralized the pre-demineralized dentin, even after prolonged fluid-challenge similar to that in oral environment. The novel PAMAM plus NACP composite method is promising to provide long-term tooth protection and caries inhibition.