Long Wavelength Light Responsive Composite Biomaterials In Oral Health Protection

With the development of aesthetic standards,tooth discoloration has become an increasingly common aesthetic problem.In addition,dental caries is recognized as the most common non-communicable disease worldwide recording to the World Health Organization.In view of the above common dental diseases,traditional treatment methods cannot controllably target the damaged sites,and the single effect as well as the low efficacy also limit the treatment application.Therefore,an intelligent light-controlled（green light response）composite biomaterial（BC-SA）was designed for non-destructive tooth whitening and caries prevention,and a near-infrared and p H dual-responsive composite material（MPC-CB）was proposed for caries prevention and remineralization.It provides new strategies for the maintenance and treatment of dental health.The main contents of this paper are as follows:The chapter 1:We have introduced the application of responsive materials in the field of oral cavity,the overview and research status of tooth staining and caries.Finally,the basis of the topic selection and innovation of this paper are discussed.The chapter 2:Biofilm-driven caries and tooth discoloration are two major problems in oral health care.The current methods have the disadvantages of insufficient biofilm targeting and irreversible enamel damage.Herein,an injectable sodium alginate hydrogel membrane（BC-SA）doped with bismuth oxychloride(Bi₁₂O₁₇Cl₂)and cubic cuprous oxide（Cu₂O）nanoparticles was designed to simultaneously achieve local tooth whitening and biofilm removal through a photodynamic dental therapy process.This fast cross-linked hydrogel could form a biofilm removal coating on the target teeth surface precisely.Afterward,reactive oxygen species（ROS）was effectively released on demand under green light,which could not only eradicate the biofilm but also whiten tooth non-destructively through a facile manner without significant damage to both enamel and biological cells.After the usage,the removal of this hydrogel could also enhance the effect of biofilm destruction and caries prevention.The chapter 3:The specific processes of caries are the demineralization of inorganic matter and decomposition of organic matter in hard tooth tissue caused by acid products from bacterial biofilm.It remains challenges for current practice to specifically identify,intervene accurately,reverse the caries environment and repair the defect.Herein,a composite responsive foam brace loaded with magnesium organic framework（MPC-CB）was designed for caries prevention and tooth remineralization.MPC could intelligently release organic antibacterial molecules（gallic acid）and mineralized ions(Mg²⁺,Ca²⁺,PO₄^3-)under acidic conditions（low p H value）of biofilm infection,regulating p H value and killing bacteria,which could not only reverse the cariogenic environment at both p H and microbial levels but also promote self-healing of demineralized teeth at both the micro-structure and mechanical properties.Additionally,due to the good photothermal conversion efficiency,MPC could further enhance the destruction of bacterial biofilms by inhibiting virulence genes and destroying bacterial adhesion under near infrared（NIR）irradiation.This p H and NIR dual-responsive intelligent material with antibacterial,microenvironment regulatory and facilitating restorative function holds great promise in oral dental care.