Dental remineralization via poly(amido amine) and restorative materials containing calcium phosphate nanoparticles

Tooth decay is prevalent,and secondary caries causes restoration failures,both of which are related to demineralization.There is an urgent need to develop new therapeutic materials with remineralization functions.This article represents the first review on the cutting edge research of poly(amido amine)(PAMAM) in combination with nanoparticles of amorphous calcium phosphate (NACP).PAMAM was excellent nucleation template,and could absorb calcium (Ca) and phosphate (P) ions via its functional groups to activate remineralization.NACP composite and adhesive showed acid-neutralization and Ca and P ion release capabilities.PAMAM +NACP together showed synergistic effects and produced triple benefits: excellent nucleation templates,superior acidneutralization,and ions release.Therefore,the PAMAM+NACP strategy possessed much greater remineralization capacity than using PAMAM or NACP alone.PAMAM+NACP achieved dentin remineralization even in an acidic solution without any initial Ca and P ions.Besides,the long-term remineralization capability of PAMAM+NACP was established.After prolonged fluid challenge,the immersed PAMAM with the recharged NACP still induced effective dentin mineral regeneration.Furthermore,the hardness of predemineralized dentin was increased back to that of healthy dentin,indicating a complete remineralization.Therefore,the novel PAMAM+NACP approach is promising to provide long-term therapeutic effects including tooth remineralization,hardness increase,and caries-inhibition capabilities.

Novel dental implant modifications with two-staged double benefits for preventing infection and promoting osseointegration in vivo and in vitro

Peri-implantitis are a major problem causing implant failure these days.Accordingly,anti-infection during the early stage and subsequent promotion of osseointegration are two main key factors to solve this issue.Micro-arc oxidation(MAO)treatment is a way to form an oxidation film on the surface of metallic materials.The method shows good osteogenic properties but weak antibacterial effect.Therefore,we developed combined strategies to combat severe peri-implantitis,which included the use of a novel compound,PD,comprising dendrimers poly(amidoamine)(PAMAM)loading dimethylaminododecyl methacrylate(DMADDM)as well as MAO treatment.Here,we explored the chemical properties of the novel compound PD,and proved that this compound was successfully synthesized,with the loading efficiency and encapsulation efficiency of 23.91%and 31.42%,respectively.We further report the two-stage double benefits capability of PD+MAO:(1)in the first stage,PD+MAO could decrease the adherence and development of biofilms by releasing DMADDM in the highly infected first stage after implant surgery both in vitro and in vivo;(2)in the second stage,PD+MAO indicated mighty anti-infection and osteoconductive characteristics in a rat model of peri-implantitis in vivo.This study first reports the two-staged,double benefits of PD+MAO,and demonstrates its potential in clinical applications for inhibiting peri-implantitis,especially in patients with severe infection risk.