Basic Study On GQ High-strength Fiber Composite Resin Periodontal Splint

Part One The influence of different components of resinmatrix on bonding strength of GQ high-strength fibercomposite resin periodontal splintObjective:To investigate the influence of different components of resin matrix on bonding strength of GQ high-strength fiber composite resin periodontal splint to enamel.Methods:GQ high-strength fiber composite resin periodontal splints were made of fiberglass with surface modification and photocurable resin which use different diluents(MMA or TEGDMA).Depending on different diluents in the resin matrix,the GQ high-strength fiber composite resin periodontal splints were randomly divided into two groups.Group A:GQ high-strength fiber composite resin periodontal splints contained TEGDMA;Group B:GQ high-strength fiber composite resin periodontal splints contained MMA.Twelve freshly extracted sound human mandibular first molars were used in the study.The enamel of the samples had been ground along the axis of teeth at the buccal direction,in order to prepare flat enamel surfaces.Teeth were bonded with GQ high-strength fiber composite resin periodontal splints using 3M FiltekXT Z350 flowable nanocomposite.Bonding strengths were tested for all the specimens with an universal testing machine.Data were statistically analyzed using t-test for comparison.The microstructure of the fracture surface was observed and compared.Results:Different components of resin matrix affected the bonding strength of GQ high-strength fiber composite resin periodontal splint.GQ high-strength fiber composite resin periodontal splint used MMA as diluent presented the better bonding strength(15.37±4.29MPa);while bonding strength of group A was 8.40±2.09MPa,which showed significant difference compared with each other(P<0.05).The metallographic microscope showed that the fibre/resin interface fracture rate of group A was 16.67%which was 9.26%in group B.Resin tags in enamel-resin interface can be seen by SEM in group A and group B.Energy dispersive spectrometer also confirmed the composition of the resin tags.Conclusions:Stable structure can be made by Bis-GMA,TEGDMA and Bis-GMA,MMA with fiberglass in a certain condition.The bonding strength of the composite is better when the diluent is MMA.Part Two The effect of different prepolymerization temperatures of resin matrix on plasticity and bonding strength of GQ high-strength fiber composite resin periodontal splintObjective:To compare the effect of different prepolymerization temperatures of resin matrix on plasticity and bonding strength of GQ high-strength fiber composite resin periodontal splint to enamel.Methods:GQ high-strength fiber composite resin periodontal splints were made of fiberglass with surface modification and photocurable resin which experienced 2h different prepolymerization temperatures.According to different prepolymerization temperatures,GQ high-strength fiber composite resin periodontal splints were randomly divided into four groups.Group C:GQ high-strength fiber composite resin periodontal splints prepolymerized 60 C2h;Group D:GQ high-strength fiber composite resin periodontal splints prepolymerized 70?2h;Group E:GQ high-strength fiber composite resin periodontal splints prepolymerized 800C2h;Group F:GQ high-strength fiber composite resin periodontal splints prepolymerized 90 C2h.The plasticity after prepolymerizing was observed.Eighteen freshly extracted sound human mandibular first molars were used in the study.The enamel of the samples had been ground along the axis of teeth at the buccal direction,in order to prepare flat enamel surfaces.Bonding strengths were tested for all the specimens with an universal testing machine.Data were statistically analyzed using one-way ANOVA.The microstructure of fracture section was observed and optimum prepolymerization temperature was detemined.Results:Different prepolymerization temperatures of resin matrix affected the bonding strength of GQ high-strength fiber composite resin periodontal splint.GQ high-strength fiber composite resin periodontal splint which experienced prepolymerizing 80? showed the better bonding strength(14.51±0.96MPa);while bonding strength of group C was 10.93±1.91MPa,which showed significant difference compared with each other(P<0.05).The metallographic microscope showed that the fibre/resin interface fracture rate of group C was 22.22%which was 25.93%in group D,31.48%in group E.The plasticity of group D and group E was acceptable.Conclusions:GQ high-strength fiber composite resin periodontal splint that prepolymerized 800C shows better bonding strength.The plasticity of GQ high-strength fiber composite resin periodontal splint after prepolymerizing 70? or 80? was acceptable.Part Three The influence of different resin adhesive systems on bonding strength of GQ high-strength fiber composite resin periodontal splintObjective:To evaluate the influence of different resin adhesive systems on bonding strength of GQ high-strength fiber composite resin periodontal splint to enamel.Methods:GQ high-strength fiber composite resin periodontal splints were made of fiberglass with surface modification and photocurable resin which contained Bis-GMA and TEGDMA.Depending on the type of dental resin adhesive systems,the GQ high-strength fiber composite resin periodontal splints were randomly divided into two groups.Group G:teeth were bonded with GQ high-strength fiber compositeresin periodontal splints using 3M RelyX Unicem;Group H:teeth were bonded with GQ high-strength fiber composite resin periodontal splints using 3M FiltekXT Z350 flowable nanocomposite.Twelve freshly extracted sound human mandibular first molars were used in the study.The enamel of the samples had been ground along the axis of teeth at the buccal direction,in order to prepare flat enamel surfaces.Bonding strengths were tested for all the specimens with an universal testing machine.Data were statistically analyzed using t-test for comparison.The microstructure of fracture section was observed and compared.Result:Different resin adhesive systems had no obvious influence on bonding strength of GQ high-strength fiber composite resin periodontal splint to enamel.The values of bonding strength on enamel of molars were compared.There was no significant difference between group G(11.14±4.56MPa)and group H(8.40±2.09MPa)(P>0.05).The metallographic microscope showed that the fibre/resin interface fracture rate of group G was 38.89%which was 16.67%in group H.Resin tags in enamel-resin interface can be seen by SEM.Energy dispersive spectrometer also confirmed the composition of the resin tags.Conclusions:There is no significant difference on bonding strength between utilizing 3M RelyX Unicem and 3M FiltekXT Z350 flowable nanocomposite.