calcium silicate - based dental material , known as mineral trioxide aggregate ( mta ) , was 
 first described in the dental scientific literature in 1993 , and received us food and drug administration approval 
 for endodontic use in 1998 . over the 
 last decade , mta has gained great popularity , especially in endodontic and pediatric 
 dentistry , because it possesses improved physical and regenerative characteristics : it 
 supports cementum regrowth , has low 
 solubility after setting , can set in 
 a wet environment , facilitates the control of bleeding , provides a strong barrier for 
 bacterial leakage , and can induce mineralized tissue formation . these advanced properties mean that mta is one of the 
 most successfully used materials in clinical procedures , especially endodontic and 
 surgical applications , including direct pulp capping , apexification , regenerative 
 endodontic treatment ( apexogenesis ) , pulpotomy , and the sealing of perforations . it can 
 also be used as a root - end filling material after root - end resection . mta is primarily composed of tricalcium and dicalcium silicate and is not only used in 
 the treatment of mature or immature permanent teeth , but also in primary teeth 
 treatment . moreover , it has recently been proposed as an alternative agent to 
 formocresol for pulpotomy treatment in primary molars . several 
 studies have investigated the success of mta compared to formocresol , as well as other 
 treatments such as ferric sulfate and calcium hydroxide , and it has exhibited a 
 significantly improved clinical performance independent of the time until exfoliation of 
 the primary molar . despite its unique combination of favorable properties , mta has 
 some critical shortcomings , namely the prolonged setting time , the high solubility 
 during the setting time , the potential for discoloration , and difficultly in 
 handling . several new calcium silicate - based capping materials have recently been developed in 
 response to the growing demand to overcome the disadvantages of mta . biodentine ( septodont , saint maur des fosses , france ) , the new 
 high - purity , calcium silicate - based dental cement , was designed as a dentin substitute 
 for resin composite restorations , pulp capping , and endodontic repair material . biodentine contains tricalcium silicate , calcium carbonate ( filler ) , 
 zirconium oxide ( radiopacifier ) , and a water - based liquid composed of calcium chloride 
 as a water - reducing agent for shorter initial and final setting times , as it also 
 accelerates the rate of early strength development . biodentine has improved 
 sealing ability , higher compressive strengths , shorter setting time ( 10 minutes ) , 
 greater biocompatibility , bioactivity and biomineralization properties than 
 mta . moreover , biodentine shows improved antibacterial 
 properties compared to mta , as well as a low cytotoxic effect . resin composites and glass ionomer cements ( gics ) are very popular in restorative 
 dentistry because of their esthetic qualities . they can not be placed directly over 
 freshly mixed mta because they can affect its setting , and the etching and rinsing of 
 unset mta can dislodge the material . however , it has been claimed that the setting time 
 of biodentine is 12 minutes , so the hypothesis is that resin composites and 
 gics can be layered over set biodentine after 12 minutes , which might enable 
 single - visit procedures . however , the strength with which restorative materials bond to biodentine is 
 unclear . in this study , we evaluated the bond strength of methacrylate - based ( mb ) 
 composites , silorane - based ( sb ) composites , and gic when used with 
 biodentine and mta . the materials used in this study included tricalcium silicate - based cement 
 ( biodentine , septodont , saint maur des fosses , france ) , white mta 
 ( proroot mta , dentsply tulsa dental , tulsa , ok , usa ) , mb composite resin ( aelite , bisco , 
 inc . , schaumburg , il , usa ) , sb composite resin ( filtek(tm ) silorane , 3 m espe , st . paul , 
 mn , usa ) , and conventional gic ( gc fuji ix , gc , tokyo , japan ) . the application steps for 
 biodentine and resin composites , as well as the powder - to - liquid ratios 
 of mta and gics recommended by the manufacturers , are listed in figure 1 . manufacturer and application details of the materials used in the study acrylic blocks ( n=90 ) with 2 mm high and 5 mm diameter central holes were prepared . 
 in 45 of the samples , the holes were fully filled with biodentine . in the 
 other 45 samples , the holes were fully filled with mta . biodentine and mta specimens were stored at 37c in 100% humidity for 
 respectively 15 minutes and 96 hours for setting . after the settings , both the biodentine and the mta samples were randomly 
 divided into 3 subgroups of 15 specimens each : group 1 : methacrylate - based ( mb ) 
 composite ; group 2 : silorane - based ( sb ) composite ; and group 3 : glass - ionomer cement 
 ( gic ) . in groups 1 and 2 , the corresponding adhesive system was applied over the 
 biodentine and mta samples according to the manufacturers ' 
 instructions , as displayed in figure 1 . each 
 resin composite or gic specimen was placed at the center of the 
 biodentine and the mta surface by placing the packing materials into 
 cylindrically shaped plastic tubes with internal diameter of 2 mm and height of 2 mm . the composite specimens were cured with a light - emitting diode light cure ( valo led , 
 ultradent , south jordan , usa ) with an intensity of 1,200 mw / cm for 20 
 seconds . the gic specimens were allowed to set for 10 minutes within the plastic 
 tubes . after the polymerization or setting process , the plastic tubes were removed 
 carefully and the specimens were stored at 37c in 100% humidity for 24 hours . all 
 the samples were prepared and tested by a single investigator ( k.c . ) . for the sbs test , each block was secured in a universal testing machine ( instron , 
 ags-1000kgw ; shimadzu corp . a chisel - edge plunger was 
 mounted onto the movable crosshead of the testing machine and positioned so that the 
 leading edge was aimed at the biodentine or the mta base / adhesive 
 interface ( figure 2 ) . the force required to 
 remove the restorative material was measured in newtons ( n ) ( 1 mpa=1 
 n / mm ) , and the sbs was then calculated by dividing the peak load values 
 by the restorative material base area ( 3.14 mm ) . schematic illustration of the shear bond strength test set - up all calculations were processed using the statistical package for the social sciences 
 ( spss ) statistical software , version 16 ( spss inc . , chicago , il , usa ) . the 
 kolmogorov - smirnov test was used to evaluate the normality of the data distribution . the mean 
 bond strengths of the groups were compared using one - way analysis of variance ( anova ) 
 and tukey 's post - hoc test ( honestly significant difference ) was used 
 for a two - by - two comparison ( p<0.05 ) . acrylic blocks ( n=90 ) with 2 mm high and 5 mm diameter central holes were prepared . 
 in 45 of the samples , biodentine and mta specimens were stored at 37c in 100% humidity for 
 respectively 15 minutes and 96 hours for setting . after the settings , both the biodentine and the mta samples were randomly 
 divided into 3 subgroups of 15 specimens each : group 1 : methacrylate - based ( mb ) 
 composite ; group 2 : silorane - based ( sb ) composite ; and group 3 : glass - ionomer cement 
 ( gic ) . in groups 1 and 2 , the corresponding adhesive system was applied over the 
 biodentine and mta samples according to the manufacturers ' 
 instructions , as displayed in figure 1 . each 
 resin composite or gic specimen was placed at the center of the 
 biodentine and the mta surface by placing the packing materials into 
 cylindrically shaped plastic tubes with internal diameter of 2 mm and height of 2 mm . the composite specimens were cured with a light - emitting diode light cure ( valo led , 
 ultradent , south jordan , usa ) with an intensity of 1,200 mw / cm for 20 
 seconds . the gic specimens were allowed to set for 10 minutes within the plastic 
 tubes . after the polymerization or setting process , the plastic tubes were removed 
 carefully and the specimens were stored at 37c in 100% humidity for 24 hours . all 
 the samples were prepared and tested by a single investigator ( k.c . ) . for the sbs test , each block was secured in a universal testing machine ( instron , 
 ags-1000kgw ; shimadzu corp . a chisel - edge plunger was 
 mounted onto the movable crosshead of the testing machine and positioned so that the 
 leading edge was aimed at the biodentine or the mta base / adhesive 
 interface ( figure 2 ) . the force required to 
 remove the restorative material was measured in newtons ( n ) ( 1 mpa=1 
 n / mm ) , and the sbs was then calculated by dividing the peak load values 
 by the restorative material base area ( 3.14 mm ) . schematic illustration of the shear bond strength test set - up all calculations were processed using the statistical package for the social sciences 
 ( spss ) statistical software , version 16 ( spss inc . , chicago , il , usa ) . the 
 kolmogorov - smirnov test was used to evaluate the normality of the data distribution . the mean 
 bond strengths of the groups were compared using one - way analysis of variance ( anova ) 
 and tukey 's post - hoc test ( honestly significant difference ) was used 
 for a two - by - two comparison ( p<0.05 ) . the anova that compared the experimental groups 
 revealed the presence of significant differences among the groups ( p<0.001 ) . the 
 highest ( 17.7 mpa ) and the lowest ( 5.3 mpa ) bond strength values were recorded for the 
 mb composite - biodentine and the gic - mta , respectively . shear bond strength values of restorative materials to biodentine 
 and conventional mineral trioxide aggregate ( mta ) there was a statistically significant difference although the mb composite showed significantly higher bond strength to 
 biodentine than it did to mta ( p<0.001 ) , the sb composite and gic 
 showed similar bond strength performance with mta compared with biodentine 
 ( p=0.73 and p=0.38 , respectively ) . the post - hoc test indicated that the 
 mb composite showed significantly higher bond strength to biodentine and mta 
 ( p<0.001 ) than the other restorative materials . the sb composite and the gic 
 specimen , however , demonstrated a similar sbs ( p=0.17 ) . we designed the present study to evaluate and compare the shear bond strength ( sbs ) of 
 mb composites , sb composites , and conventional gic materials when used with 
 biodentine and mta . several studies have reported obtaining optimal sbs 
 with total etch adhesive systems 
 when comparing the sbs of various adhesive systems used with mta for different time 
 intervals , as phosphoric acid has been shown to produce deeper and more retentive micro 
 porosity than even the strongest self - etching adhesive . it has also been demonstrated 
 that restorative procedures should be postponed for at least 72 to 96 hours after mixing mta to allow the material 
 to achieve its optimum physical properties . the purpose of the present study was not to 
 assess the waiting times with regard to the sbs of restorative materials when used with 
 mta , since this has already been evaluated in numerous studies , as previously mentioned . 
 therefore , the mta and biodentine subjects remained untouched for 96 hours 
 and 15 minutes , respectively , after application , and we applied the mb composite with a 
 total etch adhesive system before the placement of the composite resin restorations . the strength of the bond between the restorative material and the enamel / dentin , as well 
 as between the restorative material and the cavity liner , is one of the most critical 
 factors for quality dental filling treatment . a bond strength ranging from 17 mpa to 20 
 mpa may be required to sufficiently resist contraction forces and produce gap - free 
 restoration margins . our findings 
 demonstrated that the mb composite with biodentine showed the highest bond 
 strength , and only this group reached an optimal shear bond , with a mean 17.7 mpa sbs 
 value ( table 1 ) . biodentine 
 significantly increased the sbs value for the ms composite compared to mta , and it 
 reached the optimal sbs value . with regard to the mb composite , the difference in the 
 sbs value for biodentine and mta was statistically significant ( p<0.001 ) . the results showed that although the sbs values of the sb composite and gic that were 
 used with biodentine ( 8.0 mpa and 6.7 mpa , respectively ) were higher than 
 their sbs when bonded to mta ( 7.4 mpa and 5.3 mpa , respectively ) , the differences 
 between these subgroups were not statistically significant ( p<0.05 ) . several studies 
 have evaluated the effects of the bond strength of mb composite resins and gic when 
 bonding to mta , and have indicated that mb composite resins showed low sbs values , 
 ranging from 5.06 mpa to 13.45 mpa , 4 to 48 hours after mixing the mta , and high sbs 
 values , ranging from 14.44 mpa to 18.25 mpa , 72 to 96 hours after mixing the mta . sbs 
 values of bonding of gic to mta were reported as 8.85 mpa and 9.16 mpa at 45 minutes and 
 72 hours , respectively , after mixing the mta . however , a resin system based on the ring - opening polymerization of silorane molecules 
 containing both hydrophobic siloxane and low shrinkage oxirane , rather than the free 
 radical polymerization of dimethacrylate ( dma ) monomers of a methacrylate - based 
 composite , has recently been developed . the ring mechanism of the silorane composite 
 allows a reduction in polymerization shrinkage and , according to some studies , siloranes 
 also decrease polymerization stress . however , the shear bond of 
 silorane - based materials when bonded to biodentine or mta is unclear . the 
 mean sbs value of the sb composite and the conventional gic used in the present study 
 did not fall within the clinically acceptable range . although the bond strength of the 
 silorane composite ( 7.7 mpa ) was greater than the bond strength of conventional gic ( 6.0 
 mpa ) , the difference was not statistically significant ( p<0.05 ) . however , the sb 
 composite has several advantages with regard to polymerization shrinkage and stress ; 
 these were lower than when the mb composite was used ( p<0.001 ) . on the basis of the methodology , the limitations of this study were ( i ) we based the sbs 
 evaluation on only one setting time , and the adhesive systems have different setting 
 times , and we did not consider alternative bonding systems , and ( ii ) the study was 
 designed as an in vitro evaluation . future studies should investigate 
 the effects of different bonding protocols on the surface and structural characteristics 
 of biodentine to provide an insight into the adhesive mechanisms of the 
 different bonding systems and biodentine under strict laboratory conditions 
 and in larger cohorts . within the limitations of this study , the new pure tricalcium - based pulp capping , repair 
 and endodontic material showed clinically acceptable and higher shear bond scores 
 compared to mta when used with the mb composite . however , the sb composite and gic 
 bonded to biodentine and mta at a fairly low strength .
objectivestricalcium silicate is the major constituent phase in mineral trioxide aggregate 
 ( mta ) . 
 it is thus postulated that pure tricalcium silicate can replace the 
 portland cement component of mta . 
 the aim of this study was to evaluate bond 
 strength of methacrylate - based ( mb ) composites , silorane - based ( sb ) composites , 
 and glass ionomer cement ( gic ) to biodentine and mineral trioxide 
 aggregate ( mta ) . 
 material and methodsacrylic blocks ( n=90 , 2 mm high , 5 mm diameter central hole ) were prepared . in 45 
 of the samples , 
 the holes were fully filled with biodentine and in the 
 other 45 samples , the holes were fully filled with mta . the biodentine 
 and the mta samples were randomly divided into 3 subgroups of 15 specimens each : 
 group-1 : mb composite ; group-2 : sb composite ; and group-3 : gic . for the shear bond 
 strength ( sbs ) 
 test , each block was secured in a universal testing machine . 
 resultsthe highest ( 17.76.2 mpa ) and the lowest ( 5.83.2 mpa ) bond strength values were 
 recorded for the mb composite - biodentine and the gic - mta , 
 respectively . 
 although the mb composite showed significantly higher bond strength 
 to biodentine ( 17.76.2 ) than it did to mta ( 8.95.7 ) ( p<0.001 ) , the sb 
 composite ( sb and mta=7.43.3 ; sb and biodentine=8.03,6 ) and gic ( gic 
 and mta=5.83.2 ; gic and biodentine=6.72.6 ) showed similar bond strength 
 performance with mta compared with biodentine ( p=0.73 and p=0.38 , respectively ) . 
 conclusionsthe new pure tricalcium - based pulp capping , repair , and endodontic material showed 
 higher shear bond scores compared to mta when used with the mb composite .