Experimental Study On The Application Three Kinds Glutinous Material To Preventive Restoration

Objective:By comparing the hermeticity of such three kinds of glutinous material as Filtek p60 posterior tooth composite resins, Filtek z350 flowable composite resins and F2000 compomer with tooth body organization, leaking conditions and surface microhardness, the research aims to explore the feasibility of early stage preventive resin restoration of fissure caries with these materials.To offer experimental evidence for selecting suitable filling materials.Methods:Experiment 1:Select 30 premolar teeth extracted for orthodontics in one month which are fully developed and without decay, crack, abrasion from outpatient clinic of oral and maxiliofacial surgery in oral hospital of Tianjin Medical University. Wash the teeth with physiological saline, remove plaque, tartar and soft tissue attached, then make stvle-1 hole (3-4mm×1.0-1.5mm×2mmiat the sunken place in the middle of each tooth. Divide the teeth into 3 groups in random, fill them with Filtek p60 posterior tooth composite resins, Filtek z350 flowable composite resins and F2000 compomer respectively. Keep the teeth in fluorescent dye liquor for 24 hours after the cycling of temperature, then take them out and make grinding slice, observe them under fluorescent microscopy. After observing, dry surface gold-plated membrane, and make morphological observation under SEM.Experiment 2:Prepare for 30 4.66-mm-diameter and 4-mm-high cylinder moulds, divide them into 3 groups randomly.10 in each. Fill them layeredly with Filtek p60 posterior tooth composite resins, Filtek z350 flowable composite resins and F2000 compomer. Measure the Vickers hardness of 3 kinds of material's plane with load of 1.96n and lasting for 30 seconds. There are 10 samples in each group and 5 measuring point on each sample's surface. The average of 50 measured value is the hardness value of that material. Result:In 3 kinds of glutinous material, the leaking deepness of Filtek z350 flowable composite resins is the least'77.16±10.25um,p<0.05). while there is no remarkable difference between Filtek p60 posterior tooth composite resins and F2000 compomer. The Vickers hardness of Filtek p60 posterior tooth composite resins is the highest (291.20±21.98 Mpa,p<0.05). while there is no remarkable difference between Filtek z350 flowable composite resins and F2000 compomer. Under SEM Filtek z350 is closed to the bond interface of the teeth, and presents fine resin turkestan sample structure, therefore can obtain better edge leakproofness.Conclusion:In these three kinds of glutinous restoring material, Filtek z350 flowable composite resins shows the least leaking depth. Filtek p60 posterior tooth composite resins shows the best microhardness and the best resistance to compression and crack. It can achieve desired effect when used to restore a larger defect area of caries hole. In restoring the early stage fissure caries of young permanent teeth, flowable composite can replace traditional composite resin to reduce microleakage, and reserve healthy tooth organization in maximum.