1.β-O-4 Lignin-derived New Hydrogen Donors For Photoinitiating Systems In Dental Materials 2.Case Reports Of Four-dimensional Digital Design Of The Functional Rehabilitation In Esthetic Zone

Part 1 β-O-4 lignin-derived new hydrogen donors for photoinitiating systems in dental materialsObjectives.The aim of this study is to develop seven new hydrogen donors HDA-HDG derived from β-O-4 lignin model combined amine free photo-initiating system(PIs)for the dental methacrylate resins.The newly developed amine free PIs(HDs/CQ/Iod)are compared with CQ/EDB system to evaluate the performance of polymerization kinetics,C-H bond dissociation energies,bleaching property,color stability and cytotoxicity of the obtained dental resin.Methods.1.Seven novel hydrogen donor HDA-HDG were formulated and were characterized molecularly with 1H NMR.The CQ/EDB PIs was blended with Bis-GMA/TEGDMA as the control group,and the HDs-based were as the experimental group.2.FTIR-ATR was used to investigate the polymerization kinetics and double bond conversion.3.Bleaching property and color stability were evaluated using a spectrophotometer.4.Molecular orbitals calculations were used to demonstrate C-H bond dissociation energies of novel HDs,which evaluate the hydrogen donor properties.5.Depth of cure of the resin using CQ/HDs were compared to the CQ/EDB.6.Cytotoxic potential of CQ/HDs and CQ/EDB was studied and compared using tissue of mouse fibroblasts(L929 cells).Results.1.The methods of synthesis of a novel hydrogen donor HDA-HDG were not complex.The compounds were powders,solids or oily,and the 1H NMR results of them were as expected.2.The degree of conversion and rate of polymerization of the new developed PIs exhibited satisfactory results with FTIR-ATR.And all of HD-based PIs almost completed the photopolymerization in 10 s.3.b*values demonstrated HD-based PIs exhibited good bleaching properties.Especially,HDD/CQ/Iod showed exceptional bleaching properties.Water sorption had little influence on deterioration of HD-based PIs in color,expert for HDD/CQ/Iod,HDA/CQ/Iod.And short-term strong illumination had little influence on deterioration in color of CQ/HDs.4.All HDs contained C-H bonds with lower dissociation energies compared to the EDB based group by molecular orbitals calculations.The result demonstrated HDs had excellent co-initiating performances in above polymerization reactions.5.Regarding to depth of cure,all HD-based group exhibited satisfactory results.Especially,HDA,HDB,HDC,HDE group showed better properties than EDB-based one.6.Cytotoxicity of HD-based group are similar to CQ/EDB group.Conclusion:The new HDs-based systems,which derived from lignin model,presenting a promising strategy to improve co-initiating ability,bleaching property,color stability and depth of cure.The results of cytotoxic potential are similar with CQ/EDB.Moreover,lignin is widely occurring in nature,therefore the co-initiators conform with conception of sustainable development.This paper encouraged the research and application of lignin in dental light-curing resins.Part 2 Case reports of four-dimensional digital design of the functional rehabilitation in esthetic zonePurpose:To explore the digital design of functional and esthetic rehabilitation with dynamic 4D virtual patient.Methods:This digital workflow using extraoral facial scan,intraoral scans and jaw motion data to create a dynamic 4D virtual patient with craniofacial soft tissue,dental tissues and motion trajectories.The virtual patient was used as assisted tools for aesthetic smile and lingual morphology design.Preoperative and postoperative trajectories,as well as satisfaction questionnaires,were used to evaluate functional and aesthetic outcomes.Results:The preoperative and postoperative trajectories of five patients had nearly identical curves.The patients were satisfied with the aesthetic morphology and color,as well as efficient protrusive movement of definitive prosthesis.The scale results revealed that the mean values of the final restorations were higher than the interim ones in terms of aesthetics,function,and treatment process.At the 1-year follow-up appointment,the patient had no reported biological or technical complications.Conclusion:The assisted digital tools provided reliable technical support for the aesthetic design and lingual morphology design.This workflow effectively reduced complications such as porcelain fracture,as well as symptoms of temporomandibular joint and masticatory muscle.