title: Biomimetic Approach for Root Caries Prevention Using a Proanthocyanidin-Rich Agent Effectiveness of plant-derived proanthocyanidins on demineralization on enamel and dentin under artificial cariogenic challenge UVA-activated riboflavin improves the strength of human dentin. Effect of Carbodiimide on Bonding Durability of Adhesive-cemented Fiber Posts in Root Canals. Effect of green tea extract on bonding durability of an etch-and-rinse adhesive system to caries-affected dentin Bonding efficacy of etch-and-rinse adhesives after dentin biomodification using ethanol saturation and collagen cross-linker pretreatment Dentin bond strengths as a function of solvent and glutaraldehyde content. Influence of EDC on Dentin-Resin Shear Bond Strength and Demineralized Dentin Thermal Properties Synergistic effect of proanthocyanidin and CPP-ACFP on remineralization of artificial root caries. Effect of proanthocyanidin incorporation into dental adhesive resin on resin-dentine bond strength. Bond Strength between Fiber Posts and Root Dentin Treated with Natural Cross-linkers. Resin bond strength to water versus ethanol-saturated human dentin pretreated with three different cross-linking agents Occlusal loading and cross-linking effects on dentin collagen degradation in physiological conditions. The use of collagen cross-linking agents to enhance dentin bond strength. Effect of flavonoids on remineralization of artificial root caries. Shear bond strength of composite to deep dentin after treatment with two different collagen cross-linking agents at varying time intervals.
abstract: The aim of this study was to evaluate the effects of a proanthocyanidin-rich grape seed extract ( GSE ) on the in vitro demineralization of root dentine . Root fragments were obtained from sound human teeth . The fragments were r and omly assigned to different treatments solutions : GSE , fluoride ( F ) , GSE+F and distilled water ( control ) . Sample s were treated daily for 30 min and subjected to a pH cycling artificial caries protocol using demineralization cycles ( 2.2 mM CaCl2 × H2O , 2.2 mM KH2PO4 , 50 mM acetic acid , pH 4.3 ) for 6 h and remineralization cycles ( 20 mM HEPES , 2.25 mM CaCl2 × H2O , 1.35 mM KH2PO4 , 130 mM KCl , pH 7.0 ) for 17.5 h. Mineral loss ( ΔZ ) and lesion depth ( LD ) were determined after 18 days of treatment/pH cycling , by transverse microradiography . GSE was able to minimize ΔZ and LD compared with the control group ( p < 0.0001 ) . The GSE+F and F groups showed the lowest values of ΔZ and LD ( p < 0.05 ) , with no statistically significant differences between them ( p = 0.554 and p = 0.726 , respectively ) . A biomimetic approach to strengthen root dentine using GSE results in decreased rates of root demineralization and may be used in conjunction with F to prevent root caries Dental caries is considered a disease of high prevalence and a constant problem in public health . Proanthocyanidins ( PAs ) are substances that have been the target of recent studies aim ing to control or treat caries . Objective The aim of this in vitro study was to evaluate the efficacy of a treatment with grape seed extract , under cariogenic challenge , to minimize or even prevent the onset of caries in the enamel and dentin . Material and Methods Blocks of enamel and dentin ( 6.0x6.0 mm ) were obtained from bovine central incisors , polished , and selected by analysis of surface microhardness ( SH ) . The blocks were r and omly divided into 3 groups ( n=15 ) , according to the following treatments : GC ( control ) , GSE ( grape seed extract ) , GF ( fluoride – 1,000 ppm ) . The blocks were subjected to 6 daily pH cycles for 8 days . Within the daily cycling , the specimens were stored in buffered solution . The blocks were then analyzed for perpendicular and surface hardness and polarized light microscopy . Results The means were subjected to statistical analysis using the ANOVA and Fisher ’s PLSD tests ( p<0.05 ) . For enamel SH , GF showed the highest hardness values . In the dentin , GF was also the one that showed higher hardness values , followed by GSE . Regarding the cross-sectional hardness values , all groups behaved similarly in both the enamel and dentin . The sample s that were treated with GSE and fluoride ( GF ) showed statistically higher values than the control . Conclusion Based on the data obtained in this in vitro study , it is suggested that grape seed extract  inhibits demineralization of artificial carious lesions in both the enamel and dentin , but in a different scale in each structure and in a smaller scale when compared to fluoride The aim of this study was to evaluate the effects of UVA-activated riboflavin ( UVA-RF ) on the mechanical properties of non-demineralized human dentin . Dentin specimens obtained from 20 teeth were r and omly divided into the following four groups : group 1 ( control ) : no treatment , group 2 ( low UVA-RF ) : specimens were exposed to UVA-RF for 10 min , group 3 ( medium UVA-RF ) : specimens were exposed to UVA-RF for 30 min , and group 4 ( high UVA-RF ) : specimens were exposed to UVA-RF for 60 min . Three-point flexural test and Raman spectroscopic analyses were performed . The mean flexural strengths ( MPa ) were 129.96 , 128.96 , 144.21 , and 147.54 , and the mean elastic modulus ( GPa ) were 8.59 , 8.38 , 10.21 , and 9.87 for groups 1 to 4 , respectively . Raman spectra showed chemical modifications of dental collagen under medium and high UVA-RF treatment . We conclude that medium and high UVA-RF increases the strength of non-demineralized human dentin  by collagen crosslinking This study was undertaken to investigate whether using a protein cross-linker , 1-ethyl-3-(3-dimethylaminopropyl ) carbodiimide ( EDC ) , improves bonding stability of fiber posts to root dentin using three resin cements . Sixty human maxillary central incisor roots were r and omly divided into six groups after endodontic treatment , according to the cements used with and without EDC pretreatment . In the etch- and -rinse group , 0.3 M EDC aqueous solution was applied on acid-etched root dentin prior to Excite DSC/Variolink II for post cementation . In the self-etch and self-adhesive groups , EDC was used on EDTA-conditioned root space prior to application of ED Primer II/Panavia F2.0 and Clearfil SA , respectively . After microslicing the root dentin , a push-out bond strength ( BS ) test was performed immediately or after one-year of water storage for each group . Data were analyzed using three-way analysis of variance and Tukey tests ( α=0.05 ) . A significant effect of cement type , time , EDC , and Time × Cement and Time × EDC interactions were observed ( p≤0.001 ) . EDC pretreatment did not affect immediate bonding of the three cements ( p>0.05 ) . Aging significantly reduced the BS in all the groups ( p≤0.001 ) , but EDC groups exhibited a higher BS compared with the respective control groups ( p<0.001 ) . Despite the significant effect of aging on decreasing the BS of fiber post to radicular dentin , EDC could diminish this effect for the three tested cements ABSTRACT Objective Green tea extract has been advocated as a matrix metalloproteinase ( MMP ) inhibitor ; however , its effect on bond durability to caries-affected dentin has never been reported . Thus , the aim of this in vitro study was to evaluate the effect of two MMP inhibitors ( 2 % chlorhexidine and 2 % green tea extract ) , applied after acid etching , on bond durability of an etch- and -rinse adhesive system to caries-affected dentin . Material and Methods Occlusal enamel was removed from third molars to expose the dentin surface , and the molars were su bmi tted to a caries induction protocol for 15 days . After removal of infected dentin , specimens were conditioned with 37 % phosphoric acid ( 15 seconds ) and r and omly divided into three groups , according to the type of dentin pretreatment ( n=10 ) : NT : no treatment ; GT : 2 % green tea extract ; CLX : 2 % chlorhexidine . The etch- and -rinse adhesive system ( Adper ™ Single Bond 2 , 3 M ESPE , St. Paul , MN , USA ) was applied according to the manufacturer 's instructions , and composite resin restorations were built on the dentin . After 24 hours , at 37 ° C , the resin-tooth blocks were sectioned perpendicularly to the adhesive interface in the form of sticks ( 0.8 mm2 of adhesive area ) and r and omly subdivided into two groups according to when they were to be su bmi tted to microtensile bond strength ( μTBS ) testing : immediately or 6 months after storage in distilled water . Data were reported in MPa and su bmi tted to two-way ANOVA for completely r and omized blocks , followed by Tukey ’s test ( α=0.05 ) . Results After 24 hours , there was no significant difference in the μTBS of the groups . After 6 months , the GT group had significantly higher μTBS values . Conclusion It was concluded that the application of 2 % green tea extract was able to increase bond durability of the etch- and -rinse system to dentin . Neither the application of chlorhexidine nor non-treatment ( NT - control ) had any effect on bond strength after water storage Aim : To evaluate whether the application of two simplified etch- and -rinse adhesives to biomodified dentin using ethanol-wet bonding ( EWB ) and collagen cross-linker ( CCL ) pretreatment improves their sealing ability . Material s and Methods : In 176 extracted human molars , the pulp-chambers were deroofed , and teeth were sectioned horizontally . Sample s were r and omly divided into eight groups according to four bonding techniques using two simplified etch- and -rinse adhesives ; Adper Single Bond 2 ( ASB ) and XP Bond ( XPB ) . The bonding protocol s included : ( a ) Water-wet bonding ( WWB ) ; ( b ) EWB ; ( c ) WWB and CCL application ; ( d ) EWB and CCL application . After composite resin restorations , dye leakage evaluation and scanning electron microscope analysis were done . Leakage scores were statistically analyzed using Kruskal-Wallis and Mann-Whitney U tests at a significance level of P < 0.05 . Result : For both ASB and XPB adhesives , least dye leakage was observed in EWB groups ( b and d ) ( P = 0.918 and P = 0.399 respectively ) which showed no significant difference , while maximum leakage scores were seen in WWB groups ( a and c ) . Regardless of CCL application and adhesives used , EWB technique depicted ( P = 0.003 and P = 0.004 ) significantly greater sealing ability than WWB . Conclusion : Bonding of ASB and XPB using EWB significantly improved their sealing ability . Biomodification using CCL pretreatment had no significant effect on the sealing ability of adhesives bonded with either WWB or EWB PURPOSE To evaluate the effect of the inclusion of glutaraldehyde on the shear bond strength of new ethanol-based adhesives ( Gluma Comfort Bond & Desensitizer , GCBD and Gluma Comfort Bond , GCB ) versus acetone-based Gluma One Bond ( GOB ) and a conventional three-step adhesive as a control . MATERIAL S AND METHODS Forty bovine incisors were mounted in acrylic ,  polished  to 600-grit , and r and omly assigned to four groups ( n=10 ) . Dentin was etched for 15 s using 35 % phosphoric acid , rinsed , and lightly dried . After adhesive application and curing , Charisma composite was applied in a # 5 gelatin capsule and light-cured . Specimens were loaded in shear using an Instron at 5 mm/min . Shear bond strengths were calculated by dividing failure load by bonded surface area . ANOVA showed a significant difference in means at P < 0.01 , so Tukey 's test was used for pairwise comparisons . RESULTS Mean SBS ( + /- SD , MPa ) were : GOB : 8 (4.4)ab ; GCB : 10 (4.4)ab ; GCBD : 14 (6)bc ; SBMP : 17.7 (6.4)c . Superscript letters indicate Tukey 's homogeneous subsets ( P < 0.05 ) This study aim ed to evaluate the bonding strength and thermal properties of demineralized dentin with and without EDC treatment .  Sound human molars were r and omly divided into seven treatment groups ( n = 20 ) : control , 80 % ethanol , and five EDC ethanol solutions ( 0.01–1.0 M ) . In each group , 16 sample s were used for bond strength assessment and 4 sample s were used for scanning electron microscopy ( SEM ) analysis . A further 70 intact molars were used to obtain a fine demineralized dentin powder , treated with the same solutions and were evaluated the crosslink degree by ninhydrin test and denaturation temperature ( Td ) by differential scanning calorimetry . EDC-treated specimens ( < 1.0 M ) had a higher bond strength , especially 0.3 and 0.5 M group , than the control counterpart . There was a significant drop in bond strength of 1.0 M EDC group . SEM revealed a homogeneous and regular interface under all treatments . EDC treatment significantly increased the demineralized dentin cross-link degree and Td compared with the control and ethanol treatments . The 0.3 and 0.5 M treatments showed the highest cross-link degree and Td . In terms of mechnical and theramal properties consideration , 0.3 and 0.5 M EDC solutions may be favorable for when applied with etch- and -rinse adhesives , but it is still needed further long-term study BACKGROUND This study evaluated the synergistic effect of proanthocyanidin ( PA ) and casein phosphopeptide amorphous calcium fluoride phosphate ( CPP-ACFP ) on remineralization of artificial root caries . METHODS Demineralized root fragments ( n = 90 ) were r and omly divided into six groups based on treatments : ( 1 ) 6.5 % PA ; ( 2 ) CPP-ACP ; ( 3 ) CPP-ACFP ; ( 4 ) CPP-ACFP + 6.5 % PA ; ( 5 ) 1000 ppm fluoride ; and ( 6 ) deionized water ( control ) . Each specimen was immersed in demineralizing solution for 14 h , testing solutions/pastes for 2 h , remineralizing solution for 8 h and pH cycling was performed at 37 ° C for 8 days . Specimens were evaluated using transverse microradiography ( lesion depth and mineral loss ) , Knoop microhardness and confocal laser scanning microscopy . RESULTS Lesion depth was significantly lower in CPP-ACFP+PA and 1000 ppm fluoride groups ( p < 0.001 ) with no significant difference between the two groups ( p > 0.05 ) . Mineral loss was the lowest in CPP-ACFP+PA group ( p < 0.05 ) . Fluoride and CPP-ACFP groups showed similar mineral gain ( p > 0.05 ) . Artificial caries lesions treated with CPP-ACFP+PA showed significantly higher microhardness values at 130 μm and 150 μm from the surface ( p < 0.05 ) . CONCLUSIONS Combined use of PA and CPP-ACFP has a synergistic effect on root caries remineralization by enhancing mineral gain and increasing hardness of artificial root caries OBJECTIVES This study evaluated the effect of proanthocyanidin ( PA ) incorporation into experimental dental adhesives on resin-dentine bond strength . METHODS Four experimental hydrophilic adhesives containing  different PA concentrations were prepared by combining 50wt% resin comonomer mixtures with 50wt% ethanol . Proanthocyanidin was added to the ethanol-solvated resin to yield three adhesives with PA concentrations of 1.0 , 2.0 and 3.0wt% , respectively . A PA-free adhesive served as the control . Flat dentine surfaces from 40 extracted third molars were etched with 32 % phosphoric acid . The specimens were r and omly assigned to one of the four adhesive groups . Two layers of one of the four experimental adhesives were applied to the etched dentine and light-cured for 20s . Composite build-ups were performed using Filtek Z250 ( 3 M ESPE ) . After storage in distilled water at 37 ° C for 24h , twenty-four bonded teeth were sectioned into 0.9 mm × 0.9 mm beams and stressed to failure under tension for bond strength testing . Bond strength data were evaluated by one-way ANOVA and Tukey 's test ( α=0.05 ) . Interfacial nanoleakage was examined in the remaining teeth using a field-emission scanning electron microscope and analysed using the Chi-square test ( α=0.05 ) . RESULTS No significant difference in bond strength was found amongst PA-free , 1 % and 2 % PA adhesives . However , incorporation of 3 % PA into the adhesive significantly lowered bond strength as demonstrated by a greater number of adhesive failures and more extensive nanoleakage along the bonded interface . CONCLUSION Incorporation of 2 % proanthocyanidin into dental adhesives has no adverse effect on dentine bond strength . CLINICAL SIGNIFICANCE The addition of proanthocyanidin to an experimental adhesive has no adverse effect on the immediate resin-dentine bond strength when the concentration of proanthocyanidin in the adhesive is less than or equal to 2 % INTRODUCTION The aim of this study was to investigate the effects of a proanthocyanidin-rich extract ( grape seed extract [ GSE ] ) on the bond strength and stability of the adhesion of fiber posts to the root dentine using 2 adhesive systems : a total-etch and a self-etch adhesive system . METHODS Single-rooted human teeth were r and omly divided into 6 groups : G1 ( control ) , untreated + total-etch adhesive Adper Scotchbond Multi- Purpose ( 3 M ESPE , St Paul , MN ) ; G2 , 6.5 % GSE for 5 minutes + SB ; G3 , 10 % GSE for 5 minutes + SB ; and G4 to G6 groups were similar to previous ones ; however , the self-etch adhesive system Clearfil SE Bond ( Kuraray , Kurashiki , Japan ) was used . Fiber posts were cemented with RelyX ARC ( 3 M ESPE ) , and the specimens were immediately tested for push out or stored for 12 months . The bond strength means were analyzed by analysis of variance and Games-Howell post hoc tests ( α = 0.05 ) . Additionally , matrix metalloproteinase inhibition by 0.65 % , 0.065 % , and 0.0065 % GSE was examined with gelatin zymography . RESULTS The use of GSE did not affect immediate bond strength to dentin and contributed to preserve the bond strength after 12 months ( P < .05 ) for both adhesives . The bond strength of SB was significantly higher than Clearfil SE Bond ( P < .05 ) . Gelatin zymography showed reduced matrix metalloproteinase activity when recombinant enzymes were incubated with both 0.65 % and 0.065 % GSE , with complete inhibition at the highest concentration . CONCLUSIONS The pretreatment with GSE can be used as a natural alternative to improve bond strength stability of dentin-adhesive interfaces in root canals Context : Resin-dentin bonds are unstable owing to hydrolytic and enzymatic degradation . Several approaches such as collagen cross-linking and ethanol-wet bonding ( EWB ) have been developed to overcome this problem . Collagen cross-linking improves the intrinsic properties of the collagen matrix . However , it leaves a water-rich collagen matrix with incomplete resin infiltration making it susceptible to fatigue degradation . Since EWB is expected to overcome the drawbacks of water-wet bonding ( WWB ) , a combination of collagen cross-linking with EWB was tested . Aim : The aim of this study was to compare the effect of pretreatment with different cross-linking agents such as ultraviolet A (UVA)-activated 0.1 % riboflavin , 1 M carbodiimide , and 6.5 wt% proanthocyanidin on the immediate and long-term bond strengths of an etch and rinse adhesive system to water- versus ethanol-saturated dentin within clinical ly relevant application time periods . Setting s and Design : Long-term in vitro study evaluating the microtensile bond strength of adhesive-dentin interface after different surface pretreatments . Subjects and Methods : Eighty freshly extracted human molars were prepared to expose dentin , etched with 37 % phosphoric acid for 15 s rinsed , and grouped r and omly . They were blot-dried and pretreated with different cross-linkers : 0.1 % riboflavin for 2 min followed by UVA activation for 2 min ; 1 M carbodiimide for 2 min ; 6.5 wt% proanthocyanidin for 2 min and rinsed . They were then bonded with Adper Single Bond Adhesive ( 3 M ESPE ) , by either WWB or EWB , followed by resin composite build-ups ( Filtek Z350 , 3 M ESPE ) . Bonded specimens in each group were then sectioned and divided into two halves . Microtensile bond strength was tested in one half after 24 h and the other after 6 months storage in artificial saliva . Statistical Analysis Used : Analysis was done using SPSS version 18 software ( SPSS Inc. , Chicago , IL , USA ) . Intergroup comparison of bond strength was done using ANOVA with post hoc Tukey 's test , and intragroup comparison was done using paired t-test . Results : The microtensile bond strength of cross-linked groups was higher compared to control group ( P < 0.001 ) . EWB showed much higher bond strength values on cross-linked dentin compared to noncross-linked dentin . UVA-activated riboflavin group exhibited highest bond strengths followed by carbodiimide and proanthocyanidin groups , respectively , on both water- as well as ethanol-saturated dentin . Even after 6 months storage , cross-linked groups showed significantly higher values compared to initial bond strength values of control group ( P < 0.001 ) . Conclusions : 0.1 % riboflavin pretreatment of dentin followed by UVA activation for 2 min exhibited highest increase in bond strength values at 24 h and least reduction in bond strength values after 6 months storage compared to other groups . Biomodification of dentin using collagen cross-linking followed by EWB exhibited a synergistic effect in improving the resin-dentin bond durability OBJECTIVE This study evaluated the ability of 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride ( EDC ) to improve the stability of demineralized dentin collagen matrices when subjected to mechanical cycling by means of Chewing Simulation ( CS ) . METHODS Demineralized dentin disks were r and omly assigned to four groups ( N=4 ) : ( 1 ) immersion in artificial saliva at 37 ° C for 30 days ; ( 2 ) pre-treatment with 0.5 M EDC for 60 s , then stored as in Group 1 ; ( 3 ) CS challenge ( 50 N occlusal load , 30 s occlusal time plus 30 s with no load , for 30 days ) ; ( 4 ) pre-treatment with 0.5 M EDC as in Group 2 and CS challenge as in Group 3 . Collagen degradation was evaluated by sampling storage media for ICTP and CTX telopeptides . RESULTS EDC treated specimens showed no significant telopeptides release , irrespective of the aging method . Cyclic stressing of EDC-untreated specimens caused significantly higher ICTP release at day 1 , compared to static storage , while by days 3 and 4 , the ICTP release in the cyclic group fell significantly below the static group , and then remained undetectable from 5 to 30 days . CTX release in the cyclic groups , on EDC-untreated control specimens was always lower than in the static group in days 1 - 4 , and then fell to undetectable for 30 days . SIGNIFICANCE This study showed that chewing stresses applied to control untreated demineralized dentin increased degradation of collagen in terms of CTX release , while collagen crosslinking agents may prevent dentin collagen degradation , irrespective of simulated occlusal function UNLABELLED Type I collagen is a major component of the hybrid layer , and improvement of its mechanical properties may be advantageous during bonding procedures . OBJECTIVE To investigate the effect of three different cross-linking agents ( Glutaraldehyde [ GD ] , Grape seed extract [ GSE ] , and Genipin [ GE ] ) on the tensile bond strength ( TBS ) of resin-dentin bonds . MATERIAL S AND METHODS Sixty-four sound human molars were collected and their occlusal surfaces were ground flat to expose dentin . Dentin surfaces were etched using a phosphoric acid and then teeth were r and omly divided according to the dentin treatment : Control group ( no treatment ) , 5 % GD , 6.5 % GSE , or 0.5 % GE . Teeth were restored either with One Step Plus or Adper Single Bond Plus adhesive systems and resin composite . After 24 h , teeth were sectioned to produce a cross-sectional surface area of 1.0 mm(2 ) and tested for tensile bond strength . Data were statistically analyzed using ANOVA and Fisher 's PLSD tests ( p < 0.05 ) . There was a statistically significant interaction between factors ( treatment and adhesive p < 0.001 ) . Treatment affected TBS ( p < 0.0001 ) , while no differences were observed between the adhesive systems ( p = 0.6961 ) . CONCLUSION Chemical modification to the dentin matrix promoted by GD and GSE , but not GE , result ed in increased bond strength . The application of selective collagen cross-linkers during adhesive restorative procedures may be a new approach to improve dentin bond strength properties BACKGROUND This study compared the effects of three flavonoids , including proanthocyanidin , naringin and quercetin on remineralization of artificial root caries . METHODS Demineralized root fragments ( n = 75 ) were r and omly divided into five groups for treatment with the remineralizing agents for 10 minutes : ( 1 ) 6.5 % proanthocyanidin ; ( 2 ) 6.5 % naringin ; ( 3 ) 6.5 % quercetin ; ( 4 ) 1000 ppm fluoride ; and ( 5 ) deionized water ( control ) . The demineralized sample s were pH-cycled through treatment solutions , acidic buffer and neutral buffer for eight days at six cycles per day . The remineralization effects were evaluated using Knoop microhardness , transverse microradiography ( lesion depth and mineral loss ) and confocal laser scanning microscopy . Microhardness at different lesion depths was analysed with two-way ANOVA and Tukey 's test , while lesion depths and mineral loss were analysed with one-way ANOVA and Tukey 's test . RESULTS Artificial caries lesions treated with fluoride and flavonoids showed significantly greater hardness than the control group ( p < 0.05 ) . Both lesion depths and mineral loss of the flavonoid treated groups were significantly lower than the control group ( p < 0.05 ) , but significantly higher than the fluoride treated group . No significant difference in lesion depth and mineral loss was found among the three flavonoids ( p > 0.05 ) . CONCLUSIONS All three flavonoids showed positive effects on artificial root caries remineralization , which are significantly lower than that of 1000 ppm fluoride OBJECTIVE This in vitro study evaluated the shear bond strength of composite resin to deep dentin using a total etch adhesive after treatment with two collagen cross-linking agents at varying time intervals . MATERIAL S AND METHODS Thirty freshly extracted human maxillary central incisors were sectioned longitudinally into equal mesial and distal halves ( n=60 ) . The proximal deep dentin was exposed , maintaining a remaining dentin thickness ( RDT ) of approximately 1 mm . The specimens were r and omly divided into three groups based on the surface treatment of dentin prior to bonding as follows : group I ( n=12 , control ) : no prior dentin surface treatment ; group II ( n=24 ) : dentin surface pretreated with 10 % sodium ascorbate ; and group III ( n=24 ) : dentin surface pretreated with 6.5 % proanthocyanidin . Groups II and III were further subdivided into two subgroups of 12 specimens each , based on the pretreatment time of five minutes ( subgroup A ) and 10 minutes ( subgroup B ) . Shear bond strength of the specimens was tested with a universal testing machine , and the data were statistically analyzed . RESULTS Significantly higher shear bond strength to deep dentin was observed in teeth treated with 10 % sodium ascorbate ( group II ) and 6.5 % proanthocyanidin ( group III ) compared to the control group ( group I ) . Among the collagen cross-linkers used , specimens treated with proanthocyanidin showed significantly higher shear bond strength values than those treated with sodium ascorbate . No significant difference was observed between the five-minute and 10-minute pretreatment times in groups II and III . CONCLUSION It can be concluded that dentin surface pretreatment with both 10 % sodium ascorbate and 6.5 % proanthocyanidin result ed in significant improvement in bond strength of resin composite to deep dentin
target: Both synthetic and naturally derived crosslinkers have been found to exhibit significant effects in biomodification of dentine via their multiple interactions with the dentine matrix .
  A stable matrix network or a durable hybrid layer in dentine bonding could be achieved , where the dentine collagen fibrils show improved biochemical and biomechanical properties and enzymatic biodegradation is reduced .
background: This aim of this review is to explore the current research related to  crosslinking agents used on dentine .