UWASH0334422890S
THE UW TEAM WILL BE RESPONSIBLE FOR CHARACTERIZING THE DURABILITY OF DENTAL ADHESIVES WITH RESPECT TO VARIOUS CHALLENGES. THE DURABILITY UNDER CYCLIC LOADING WILL BE DETERMINED IN A FOUR-POINT FIXTURE ARRANGEMENT WITHIN A HYDRATED ENVIRONMENT. UP TO THREE CHALLENGE GROUPS WILL BE ASSESSED, WHICH INCLUDE CARIOGENIC BIOFILMS (S. MUTANS, 0 D, 1 D AND 14 D), CLINICAL AGING (IN HUMAN SALIVA FOR 60 D, 120 D, AND 180 D), AND AFTER THERMAL CYCLING (UP TO 20,000 CYCLES BETWEEN 5 °C AND 60 °C). AFTER EACH CHALLENGE THE SPECIMENS WILL BE SUBJECTED TO CYCLIC FOURPOINT FLEXURE TO FAILURE TO CONSTRUCTED FATIGUE LIFE DIAGRAMS. CONTROL SPECIMENS WILL BE EVALUATED WITHOUT CHALLENGES AFTER STORAGE IN DEIONIZED WATER AT 4 °C FOR THE SAME TIME PERIODS. THE FATIGUE LIFE DISTRIBUTIONS (N = 20 /COMPOSITION/TIME POINT, INCLUDING CHALLENGED SPECIMENS AND CONTROLS) WILL BE COMPARED USING THE WILCOXON SUM RANK TEST WITH P  ¤ 0.05 CONSIDERED SIGNIFICANT. AFTER THE EXPERIMENTS THE SPECIMENS WILL BE SENT TO FORSYTH OR MARYLAND, AND SECTIONED ACCORDING TO μCT SCANS. THE PROGRESSION OF COMPOSITE DEGRADATION, INCLUDING SUBSURFACE DEMINERALIZATION, WILL BE EVALUATED VIA μCT, SEM AND HISTOLOGICAL EVALUATIONS. IN ADDITION, FOURIER TRANSFORM INFRARED MICROSCOPIC MAPPING (FTIR-μMAP), μCT AND SEM ANALYSES WILL BE USED TO IDENTIFY THE FAILURE MECHANISMS BASED ON THE SURFACE MORPHOLOGY AND SURFACE CHEMISTRY CHANGES. IN ALL WORK, A COMMERCIAL RESTORATIVE SYSTEM (3M SCOTCHBOND AND FILTEK Z250) WILL BE USED AS THE CONTROL SUBJECT TO THE SAME CHALLENGES. OPTICAL MICROSCOPY AND SEM WILL BE USED TO EVALUATE FAILURE MECHANISMS AT THE UW. FAILURE ANALYSIS AFTER DURABILITY TESTS WILL IMPROVE OUR UNDERSTANDING ON THE CONTRIBUTION OF BIOSTABILITY OF RESIN NETWORK, AM-, PR- OR RM-FUNCTIONS TO THE DURABILITY IMPROVEMENT. TO FURTHER CLARIFY THE ORIGINS OF THE FAILURES, OTHER METHODS WILL BE CARRIED OUT, SUCH AS HUMAN DENTIN HARDNESS RESTORATION TEST TO CONFIRM THE THERAPEUTIC EFFECTS OF AM- AND NACP-CONTAINING COMPOSITES.
University Of Washington
Project Grant R01DE033442
$15.2k 1/2/25 UM0334422890S
THE BIOMATERIALS LAB OF DR. HUAKUN XU AT UMB SCHOOL OF DENTISTRY WILL WORK WITH DR. JIRUN SUN ON ALL ASPECTS OF THE AIMS DESCRIBED BELOW. SPECIFICALLY, UMB WILL FOCUS ON THE DEVELOPMENT OF HIGH-PERFORMANCE RESINS FOR DENTAL ADHESIVES AND COMPOSITES IN COLLABORATION WITH DR. SUN, MECHANICAL AND PHYSICAL PROPERTIES TESTING, AND INVESTIGATION OF INTERACTIONS WITH ORAL BIOFILMS, ACID PRODUCTION, AND DENTAL CARIES-INHIBITION. SPECIFIC AIMS (SAS) OUR GOAL IS TO DESIGN, MAKE AND EVALUATE BIOSTABLE AND MULTIFUNCTIONAL DENTAL RESIN RESTORATIVES THAT ARE SUPERIOR IN PERFORMANCE AND ENDURANCE TO THE CURRENT METHACRYLATE (ESTER-BASED) RESIN RESTORATIVES WHICH CONTAINING UNPROTECTED AND HYDROLYSABLE ESTER FUNCTIONAL GROUPS. TO ACHIEVE OUR GOAL, WE WILL FORMULATE AND EVALUATE HIGH PERFORMANCE HYBRID RESIN NETWORKS THAT ARE CONSTRUCTED IN A CONTROLLED FASHION TO PROTECT ESTER FUNCTIONAL GROUPS FROM HYDROLYSIS AND ENZYMOLYSIS. MOREOVER, WE WILL FORMULATE MULTIFUNCTIONAL RESIN RESTORATIVES BY INCORPORATING ANTIMICROBIAL (AM), PROTEIN-REPELLANT (PR) AND THERAPEUTIC REMINERALIZATION (RM) POTENTIALS USING ADDITIVES AND FILLERS THAT HAVE BEEN WELL DEVELOPED FOR TRADITIONAL ESTER-BASED SYSTEMS. CONSEQUENTLY, THE MULTIFUNCTIONAL AND BIOSTABLE HYBRID RESIN SYSTEMS WILL BE TRANSFORMED INTO STRONG AND DURABLE DENTAL ADHESIVES OR RESIN COMPOSITES. ULTIMATELY, WE WILL DELIVER VARIOUS MULTIFUNCTIONAL RESTORATIVE PRODUCTS FOR DIVERSE TREATMENT NEEDS FOR DENTAL CAVITIES AFTER VIGOROUS CLINICALLY RELEVANT EVALUATIONS IN EXTRACTED HUMAN TEETH. THE FOLLOWING THREE SPECIFIC AIMS ARE PROPOSED: SPECIFIC AIM 1: TO DEVELOP HIGH PERFORMANCE RESIN NETWORKS FOR DENTAL ADHESIVES AND COMPOSITES. THE GOAL OF THIS AIM IS TO FORMULATE MULTIFUNCTIONAL HYBRID RESIN NETWORKS AND CONFIRM THEIR BIOSTABILITY USING A HIGHLY SENSITIVE BIOSTABILITY EVALUATION METHOD (HS-BEM). WE WILL FIRST ESTABLISH THE HS-BEM AS A SYSTEMATIC QUANTITATIVE METHOD THAT IS ABLE TO PROVIDE COMPARABLE NUMERICAL VALUES OF THE SMALL BIOSTABILITY VARIATIONS AMONG TRADITIONAL ESTER-BASED RESIN NETWORKS AS WELL AS DEMONSTRATE THE BIG BIOSTABILITY GAPS BETWEEN ESTER-BASED RESIN NETWORKS AND THE NEW HYBRID RESIN NETWORKS. THESE NEW HYBRID RESINS ARE EXEMPLIFIED BY POLY-U/V: A COPOLYMER OF EQUIMOLAR ESTER-BASED URETHANE DIMETHACRYLATE AND AN ETHER-BASED TRIETHYLENE GLYCOL DIVINYLBENZYL ETHER (TEG-DVBE). THE POLY-U/V IS HIGHLY STABLE UNDER ENZYME CHALLENGES. FOLLOWING THE SAME ESTER-PROTECTING POLYMERIZATION MECHANISM, WE WILL FORMULATE NEW ACIDIC HYBRID RESINS THAT WILL BE USED AS SELF-ETCH DENTAL ADHESIVES. THE BIOSTABILITY OF THESE ACIDIC HYBRID RESINS AND OTHER HYBRID RESINS WITH AM AND PR POTENTIALS WILL BE DETERMINED BY HS-BEM. THE RESULTING MULTIFUNCTIONAL HYBRID RESIN NETWORKS WITH EQUIVALENT BIOSTABILITY TO POLY-U/V WILL BE FURTHER IMPROVED AND EVALUATED IN AIMS 2 AND 3. SPECIFIC AIM 2: TO FORMULATE MULTIFUNCTIONAL RESIN RESTORATIONS WITH NEW HIGH-PERFORMANCE RESIN NETWORKS. WE HYPOTHESIZE THAT THE HYBRID RESIN NETWORKS ARE COMPATIBLE WITH ALL THE FUNCTIONAL ADDITIVES AND FILLERS THAT HAVE BEEN DEVELOPED FOR TRADITIONAL ESTER-BASED DENTAL RESINS. FROM MANY OF THESE ADDITIVES AND FILLERS, WE SELECT AM AND PR AGENTS AND RM FILLERS THAT ARE USED TO PREVENT SECONDARY CARIES AND HAVE BEEN EXTENSIVELY EVALUATED BY OUR TEAM. WE WILL COMPOSE A SERIES OF RESINS AND COMPOSITES BY SYSTEMATICALLY GROUPING THESE ADDITIVES AND FILLERS WITH THE HYBRID SYSTEMS DEVELOPED IN AIM 1. CONSEQUENTLY, WE WILL DEVELOP A BATTERY OF NEW MULTIFUNCTIONAL RESINS AND RESIN COMPOSITES WHICH HAVE EQUIVALENT OR BETTER AM, PR, AND RM PERFORMANCE THAN THEIR TRADITIONAL ESTER-BASED COUNTERPARTS. THESE NEW COMPOSITIONS WILL BE USED AS THE KEY COMPONENTS OF DENTAL RESTORATIONS E.G., ADHESIVES AND COMPOSITES, AND FURTHER EVALUATED IN AIM 3. SPECIFIC AIM 3: TO EVALUATE THE PERFORMANCE OF MULTIFUNCTIONAL RESTORATIONS IN EXTRACTED HUMAN TEETH UNDER STATIC AND CYCLIC LOADINGS. THE RESINS AND COMPOSITES DEVELOPED IN AIMS 1-2 WILL BE EVALUATED AS DENTIN ADHESIVES AND DENTAL COMPOSITES IN EXTRACTED HUMAN TEETH TO DETERMINE THE SHEAR BOND STRENGTH, TENSILE BOND STRENGTH, BONDING DURABILITY UNDER STATIC AND CYCLIC LOADINGS, AND TOOTH THERAPEUTIC CAPABILITY. WE WILL OBTAIN THE MOST CLINICALLY RELEVANT DURABILITY PERFORMANCE BY APPLYING DIFFERENT CHALLENGES INCLUDING CLINICAL AGING, THERMAL CYCLING, AND CARIOGENIC BIOFILM. IMPACT: SUCCESSFUL COMPLETION OF THE PROPOSED AIMS WILL PRODUCE A BATTERY OF MULTIFUNCTIONAL, DURABLE DENTAL RESIN RESTORATIVES FOR VARIOUS TREATMENT NEEDS OF DIFFERENT CARIES CATEGORIES. KNOWLEDGE GAINED FROM THIS STUDY WILL PROVIDE THEORETICAL RATIONALES AND EXPERIMENTAL EVIDENCE FOR DEVELOPING BIOSTABLE MATERIALS TO TREAT DENTAL CARIES AND IMPROVE HUMAN HEALTH. NARRATIVES: THE GOAL OF THIS PROPOSAL IS TO MAKE DURABLE AND MULTIFUNCTIONAL DENTAL FILLING MATERIALS THAT ARE SUPERIOR AND LONGER LASTING THAN THE TRADITIONAL ONES. THIS GOAL WILL BE ACCOMPLISHED BY SYSTEMATICALLY DESIGN, FORMULATE, AND EVALUATE DENTAL ADHESIVES AND COMPOSITES THAT ARE COMPOSED OF NEW RESIN NETWORKS, THERAPEUTIC FILLERS, AND ADDITIVES WITH ANTIMICROBIAL AND PROTEIN REPELLENT POTENTIAL. ULTIMATELY, WE WILL DELIVER VARIOUS MULTIFUNCTIONAL RESTORATIVE PRODUCTS FOR DIVERSE TREATMENT NEEDS OF DENTAL CAVITIES AFTER VIGOROUS CLINICALLY RELEVANT EVALUATIONS IN EXTRACTED HUMAN TEETH. SUMMARY: THE SHORT AVERAGE SERVICE LIFE OF CURRENT DENTAL COMPOSITE RESTORATIVE SYSTEMS AND INCREASING OCCURRENCE OF SECONDARY CARIES ADJACENT TO COMPOSITE RESTORATIONS AND SEALANTS ARE NECESSITATING THE DEVELOPMENT OF NEW, LONGER LASTING DENTAL MATERIALS HAVING NOVEL RESIN NETWORKS, MULTIFUNCTIONAL FILLERS AND ADDITIVES, AND ADHESIVE COMPONENTS. THE GOAL OF THIS PROPOSED RESEARCH IS TO DEVELOP NEW DENTAL COMPOSITE SYSTEMS, FOR USE IN RESTORATIONS, SEALANTS, AND OTHER DENTAL SERVICES THAT ARE SUPERIOR IN PROPERTIES AND ENDURANCE TO CURRENTLY USED METHACRYLATE, ESTER-BASED, SYSTEMS. THIS GOAL WILL BE ACCOMPLISHED BY DESIGNING, DEVELOPING, AND TESTING NEW AND HIGH-PERFORMANCE DENTAL RESIN RESTORATIONS THAT ARE HYDROLYSIS- AND ENZYMOLYSIS-RESISTANT AND HAVE ANTIMICROBIAL, PROTEIN-REPELLENT AND THERAPEUTIC POTENTIALS. ULTIMATELY, THE OPTIMIZED PRODUCTS AS DENTAL ADHESIVES AND RESIN COMPOSITES WILL HAVE SUPERIOR PERFORMANCE AND SERVICE LIFE TO THEIR ESTER-BASED COUNTERPARTS. WE WILL ACHIEVE OUR GOAL IN THREE SPECIFIC AIMS. IN AIM 1, WE PROPOSE TO MAKE NOVEL HYBRID RESIN NETWORKS THAT LAST FOR A LIFETIME IN THE PATIENTSÂ ORAL ENVIRONMENTS. THESE HYBRID RESIN NETWORKS WILL PROTECT ESTER-GROUPS FROM HYDROLYSIS AND ENZYMOLYSIS THROUGH A CONTROLLED ALTERNATING PACKING OF THE METHACRYLATE UNIT WITH A STYRENE-DERIVATIVE UNIT. THEY INCLUDE A BIOSTABLE ACIDIC HYBRID RESIN NETWORK FOR SELF-ETCH DENTAL ADHESIVES AND MULTIFUNCTIONAL HYBRID RESIN NETWORKS FOR DIFFERENT APPLICATIONS. THE HIGH STABILITY OF THESE HYBRID RESIN NETWORKS WILL BE EVALUATED USING A QUANTITATIVE METHOD TO COMPARE AND RANK ALL THE ESTER-BASED RESINS AND HYBRID RESINS. THE BIOSTABLE MULTIFUNCTIONAL HYBRID RESIN NETWORKS WILL BE SUBJECTED TO FURTHER ASSESSMENT AND IMPROVEMENT IN AIMS 2-3. IN AIM 2, WE WILL FORMULATE AND DEVELOP NEW MULTIFUNCTIONAL HYBRID RESINS AND RESIN COMPOSITES THAT HAVE EQUIVALENT OR BETTER ANTIMICROBIAL, PROTEIN-REPELLENT, AND THERAPEUTIC REMINERALIZATION PERFORMANCE THAN THEIR ESTER-BASED COUNTERPARTS. WE HYPOTHESIZE THAT THE HYBRID RESIN NETWORKS ARE COMPATIBLE WITH ALL THE FUNCTIONAL ADDITIVES AND FILLERS THAT ALREADY HAVE BEEN DEVELOPED FOR TRADITIONAL ESTER-BASED DENTAL RESIN NETWORKS. FINALLY, IN AIM 3, WE WILL EVALUATE THE RESINSÂ PERFORMANCE AS DENTAL ADHESIVES AND RESIN COMPOSITES IN EXTRACTED HUMAN TEETH UNDER STATIC AND CYCLIC LOADINGS. WE WILL OBTAIN THE MOST CLINICALLY RELEVANT DURABILITY PERFORMANCE BY APPLYING DIFFERENT CHALLENGES INCLUDING CLINICAL AGING, THERMAL CYCLING, AND CARIOGENIC BIOFILM. SUCCESSFUL COMPLETION OF THE PROPOSED AIMS WILL RESULT IN THE PRODUCTION OF MULTIFUNCTIONAL, DURABLE DENTAL RESIN RESTORATIVES FOR TREATMENT OF DIVERSE TYPES OF DENTAL CARIES.
University Of Maryland, Baltimore
Project Grant R01DE033442
$116.8k 1/28/25