- Email: [email protected]
Proprietary solvent enhances dentin wettability
e12
d e n t a l m a t e r i a l s 2 6 S ( 2 0 1 0 ) e1–e84
Results: E-modulus means (SD) are expressed in MPa.
R2 neat R2-10% EtOH R2-20% EtOH R3 neat R2-10%EtOH R3-20% EtOH R5 neat R5-10% EtOH R5-20% EtOH
T 0-dry
T 24 h-dry
T 3 days-water
908.8(30.6)g 912.1(1.3)g 762.9(15.3)e 1383.2(21.3)k 1143.7(4.1)I 828.9(5.6)f 642.6(8.4)d 636.8(8.9)d 331.1(3.2)a
1874(15.6)m 1251.2(4.9)j 1371(15.3)k 2366.8(24.1)p 2092.7(21.7)n 1135.9(14.5)i 1120.5(13.5)I 1355.1(10.8)k 636.2(16.7)d
1853.7(24.7)m 1104.8(13.7)i 1130.7(4.2)i 2253.3(30.8)o 1566.2(13.3)l 960.4(13.7)h 454.9(4.1)b 781.9(13.2)e 530.2(11.4)c
Different superscript letters indicate statistical differences (p < 0.05).
Conclusions: E-modulus was affected by EtOH blended within the adhesive resins. Addition of 10–20% EtOH reduced the E-modulus of all resin (p < 0.05) especially after three days of water storage. The lowest E-modulus was found for R5, the most hydrophilic blend, at all EtOH concentration after three days. In conclusion, increasing hydrophilicity and concentrations of EtOH dissolved in resin blends decreased the E-modulus compared to neat resins. doi:10.1016/j.dental.2010.08.031 24 Longevity of the bond created by 0.2% CHX-containing scotchbond 1XT A. Mazzoni 1 , F. Nato 2 , C. Nucci 1 , M. Carrilho 3 , L. 4 5 5 6 Tjäderhane , F.R. Tay , D.H. Pashley , L. Breschi 1
University of Bologna, Italy University of Urbino, Italy 3 UNIBAN, Brazil 4 University of Oulu, Finland 5 Medical College of Georgia, USA 6 University of Trieste, Italy 2
Objectives: Degradation of hybrid layers (HL) within resin-infiltrated dentin has shown to result from multiple degradation factors, including the collagenolytic activity of matrix metalloproteinases (MMPs). The use of chlorhexidine (CHX) as additional primer during dental bonding procedure for the stabilization of adhesive interface has been extensively investigated. With the attempt to simplify the bonding procedure, this study aimed to determine the effectiveness of CHX when blended within the adhesive formulation in preserving (or to preserve) the mechanical properties of hybrid layer. Materials and methods: Etched dentin substrates were equally assigned to the following groups: (1) Adper Scotchbond 1XT (SB1XT-3M ESPE; control group) and (2) 0.2% CHXcontaining SB1XT (experimental group). Composite build-ups were made and beams were prepared for microtensile bond strength testing. These specimens were either immediately pulled to failure or stored in artificial saliva for 1 year prior to be tested. Two-way ANOVA and Tukey’s test were used to analyze data. In addition, to investigate the effect of the tested adhesives on MMPs activity, gelatin zymography was performed on dentin powder pulverized from extracted human molars and treated as follow: (1) untreated mineralized dentin; (2) demineralized with 1% H3 PO4 for 10 min; demineralized with 1%
H3 PO4 for 10 min then treated (3) with SB1XT or (4) with 0.2% CHX-containing SB1XT. Results: Microtensile bond strength values and standard deviations were expressed as MPa and reported in the table. Different superscript letters indicate statistical difference (p < 0.05). Adhesive system
Time 0
Time 1 year
SB1XT 0.2% CHX-SB1XT
45.3 ± 11.3a 47.9 ± 10.0a
24.3 ± 5.4b 33.7 ± 6.9c
Gelatin zymography revealed no enzymatic activity in proteins extracted from mineralized dentin while in H3 PO4 demineralized dentin presence of MMP-2 and -9 active forms were evident. Zymograms of SB1XT-treated dentin showed MMP-2 proform and active form, and a faint band of MMP9 active form, while zymograms of CHX-containing SB1XT showed complete inhibition of MMPs activity. Conclusions: The microtensile bond strength data confirmed that when included within the adhesive formulation, 0.2% CHX significantly contributes to preserve the mechanical integrity of the HL over time. In addition, zymography analysis revealed the inhibition of dentinal MMP-2 and -9 with 0.2% CHX blended within the adhesive formulation. Further in vivo studies are needed to confirm the potential benefits of CHX-containing adhesive systems. doi:10.1016/j.dental.2010.08.032 25 Proprietary solvent enhances dentin wettability P. Mehtälä 1 , K. Tjäderhane 1
Agee 2 , L.
Breschi 3 , D.H.
Pashley 2 , L.
1
University of Oulu, Oulu, Finland Medical College of Georgia, Augusta, USA 3 University of Trieste, Italy 2
Objectives: Surface treatment such as acid etching increases dentin surface energy. The higher the energy indicated by lower contact angles, the better the association of resin onto the dentin surface and into the hybrid layer. The aim of our study was to investigate the possibility that our proprietary solvent could further increase surface energy and improve wettability of acid etched dentin. Materials and methods: Mid-coronal dentin was exposed to proprietary solvent in increasing concentrations and contact angle was measured by means of sessile drop equilibrium contact angle, using contact angle/surface energy analyzer. LVDT (linear variable differential transformer) measurements were used to investigate test solvents ability to expand collagen matrix. Contact angle results were analyzed using one-way ANOVA and Tukey’s post hoc test. Results: Contact angle decreased as the concentration of our test solvent increased. LVDT measurements showed that increase in experimental solvent concentration resulted in diminished collagen matrix expansion (Table 1). Conclusions: Dentin surface energy correlates to its wettability and therefore plays an important role in adhesion. Higher surface energy leads to stronger association between
e13
d e n t a l m a t e r i a l s 2 6 S ( 2 0 1 0 ) e1–e84
Table 1 – Contact angle measured in degrees, collagen matrix expansion expressed as percentage of fully hydrated expanded matrix. Solvent (wt%) 0% ◦
Contact angle ( )
48 ± 1.3
1% a
44 ± 2.1
2% 36 ± 2
b
3%
4%
30 ± 1.4
c
d
5%
29 ± 1.7
d
25 ± 1.9e
Solvent (wt%) 5% Expansion of dried demineralized dentin
98% ± 2%
10%a 92.5%
a
20%
30%
40%
50%
84% ± 3%
78% ± 4%
70% ± 3%
66% ± 3%
Same superscripts letters indicate no statistically significant difference (p > 0.05). a 10% expansion extrapolated from 5% and 15% results.
adhesive and the dentin surface. LVDT results showed that collagen matrix did not expand more fully with the aid of the solvent. The change in contact angle may therefore be a result of improved infiltration into acid etched dentin. Such effect would be beneficial in maximizing monomer permeation into acid-etched dentin during bonding. doi:10.1016/j.dental.2010.08.033 26 The anti-MMP activity of benzalkonium chloride M.M. Mutluay 1 , A. Tezvergil-Mutluay 1 , K.A. Agee 2 , R.M. Carvalho 3 , A. Manso 4 , F.R. Tay 2 , B.-Y. Suh 4 , D.H. Pashley 2 1
University of Turku, Finland Medical College of Georgia, USA 3 University of Sao Paulo, Brazil 4 Bisco Inc., USA 2
similar trend. BAC inhibited matrix-bound MMPs between 55 and 66% when measured as mass loss or 76–81% when measured as solubilization of collagen peptide fragments. ANOVA showed significant effect of BAC compared to control (p < 0.05). Conclusions: BAC is very effective at inhibiting both soluble and matrix-bound dentine MMPs in the absence of resins. Supported, in part, by grants R01 DE015306-06 from the NIH/NIDCR (P.I. DP) and by the Finnish Academy (P.I. ATM). doi:10.1016/j.dental.2010.08.034 27 CHX-containing adhesive inhibits dentin MMPs: A zymographic assay F. Nato 1,2 , A. Mazzoni 2 , P. Gobbi 1 , M. Carrilho 3 , G. Mazzotti 2 , F.R. Tay 4 , D.H. Pashley 4 , L. Breschi 5 1
University of Urbino, Italy University of Bologna, Italy 3 UNIBAN, Brazil 4 Medical College of Georgia, USA 5 University of Trieste, Italy 2
Objectives: Matrix metalloproteinases (MMPs) bound to dentin are known to contribute to progressive degradation of collagen fibrils in hybrid layers. Inhibition of host-derived MMPs by quaternary ammonium compounds was shown to slow the degradation. Benzalkonium chloride is a cationic surface-acting agent belonging to the quaternary ammonium group of compounds and widely used for antibacterial properties. This study evaluated the ability of benzalkonium chloride (BAC) to inhibit soluble versus bound dentine matrix metalloproteinases (MMPs). Materials and methods: The inhibitory effects of four different BAC concentrations (0.5–5 wt%) on soluble rhMMP2, 8 and 9 were initially screened using a commercially available colorimetric assay kit. Matrix-bound endogenous MMP-activity was evaluated in completely demineralized beams using two different concentrations of BAC (0.5 and 1 wt%). Each beam was either dipped into BAC for 10 or 30 s and then dropped into 1 mL of an complete medium (CM) or alternatively they were placed in either 1 mL of CM containing BAC or only CM for 30 days (control). After 30 days, changes in the dry mass of the beams or in the hydroxyproline (HYP) content of hydrolyzates of the media were quantitated as indirect measures of matrix collagen hydrolysis. The data were analyzed using ANOVA, at ˛ = 0.05. Results: All tested BAC concentrations showed an inhibition of 93–100% and were highly effective (p < 0.05) in inhibiting soluble rhMMP-2, 8 or 9. Matrix-bound MMP model showed
Objectives: Matrix metalloproteases (MMPs) are a family of Zn- and Ca-dependent enzymes involved in several developmental and disease-associated processes. Since these enzymes have been suggested as playing key roles in the degradation of resin–dentin matrices, the use of chlorhexidine (CHX, a non-toxic MMP inhibitor) as additional primer during bonding procedures has been reported to be effective in the preservation of the hybrid layer over time. The purpose of this study was to identify the effectiveness of including CHX within the formulation of a self-etch adhesive system on MMP-2 and -9 activity by means of gelatin zymography. Materials and methods: Dentin powder was pulverized from freshly extracted human molars. Four lots of dentin powder were obtained and randomly assigned to the following treatment group: (1) mineralized dentin + Adper Easy Bond (AEB; 3M ESPE, St Paul, USA); (2) mineralized dentin + 0.2% CHX-containing AEB (experimental adhesive, 3M ESPE); (3) demineralized with 1% aqueous solution of H3 PO4 for 10 min; (4) untreated mineralized dentin (control). After rinsing in acetone to remove the uncured adhesive system, protein extracts obtained from the treated dentin powder were then electrophoresed by gelatin zymography, for detection of MMPs enzyme activity.
d e n t a l m a t e r i a l s 2 6 S ( 2 0 1 0 ) e1–e84
Results: E-modulus means (SD) are expressed in MPa.
R2 neat R2-10% EtOH R2-20% EtOH R3 neat R2-10%EtOH R3-20% EtOH R5 neat R5-10% EtOH R5-20% EtOH
T 0-dry
T 24 h-dry
T 3 days-water
908.8(30.6)g 912.1(1.3)g 762.9(15.3)e 1383.2(21.3)k 1143.7(4.1)I 828.9(5.6)f 642.6(8.4)d 636.8(8.9)d 331.1(3.2)a
1874(15.6)m 1251.2(4.9)j 1371(15.3)k 2366.8(24.1)p 2092.7(21.7)n 1135.9(14.5)i 1120.5(13.5)I 1355.1(10.8)k 636.2(16.7)d
1853.7(24.7)m 1104.8(13.7)i 1130.7(4.2)i 2253.3(30.8)o 1566.2(13.3)l 960.4(13.7)h 454.9(4.1)b 781.9(13.2)e 530.2(11.4)c
Different superscript letters indicate statistical differences (p < 0.05).
Conclusions: E-modulus was affected by EtOH blended within the adhesive resins. Addition of 10–20% EtOH reduced the E-modulus of all resin (p < 0.05) especially after three days of water storage. The lowest E-modulus was found for R5, the most hydrophilic blend, at all EtOH concentration after three days. In conclusion, increasing hydrophilicity and concentrations of EtOH dissolved in resin blends decreased the E-modulus compared to neat resins. doi:10.1016/j.dental.2010.08.031 24 Longevity of the bond created by 0.2% CHX-containing scotchbond 1XT A. Mazzoni 1 , F. Nato 2 , C. Nucci 1 , M. Carrilho 3 , L. 4 5 5 6 Tjäderhane , F.R. Tay , D.H. Pashley , L. Breschi 1
University of Bologna, Italy University of Urbino, Italy 3 UNIBAN, Brazil 4 University of Oulu, Finland 5 Medical College of Georgia, USA 6 University of Trieste, Italy 2
Objectives: Degradation of hybrid layers (HL) within resin-infiltrated dentin has shown to result from multiple degradation factors, including the collagenolytic activity of matrix metalloproteinases (MMPs). The use of chlorhexidine (CHX) as additional primer during dental bonding procedure for the stabilization of adhesive interface has been extensively investigated. With the attempt to simplify the bonding procedure, this study aimed to determine the effectiveness of CHX when blended within the adhesive formulation in preserving (or to preserve) the mechanical properties of hybrid layer. Materials and methods: Etched dentin substrates were equally assigned to the following groups: (1) Adper Scotchbond 1XT (SB1XT-3M ESPE; control group) and (2) 0.2% CHXcontaining SB1XT (experimental group). Composite build-ups were made and beams were prepared for microtensile bond strength testing. These specimens were either immediately pulled to failure or stored in artificial saliva for 1 year prior to be tested. Two-way ANOVA and Tukey’s test were used to analyze data. In addition, to investigate the effect of the tested adhesives on MMPs activity, gelatin zymography was performed on dentin powder pulverized from extracted human molars and treated as follow: (1) untreated mineralized dentin; (2) demineralized with 1% H3 PO4 for 10 min; demineralized with 1%
H3 PO4 for 10 min then treated (3) with SB1XT or (4) with 0.2% CHX-containing SB1XT. Results: Microtensile bond strength values and standard deviations were expressed as MPa and reported in the table. Different superscript letters indicate statistical difference (p < 0.05). Adhesive system
Time 0
Time 1 year
SB1XT 0.2% CHX-SB1XT
45.3 ± 11.3a 47.9 ± 10.0a
24.3 ± 5.4b 33.7 ± 6.9c
Gelatin zymography revealed no enzymatic activity in proteins extracted from mineralized dentin while in H3 PO4 demineralized dentin presence of MMP-2 and -9 active forms were evident. Zymograms of SB1XT-treated dentin showed MMP-2 proform and active form, and a faint band of MMP9 active form, while zymograms of CHX-containing SB1XT showed complete inhibition of MMPs activity. Conclusions: The microtensile bond strength data confirmed that when included within the adhesive formulation, 0.2% CHX significantly contributes to preserve the mechanical integrity of the HL over time. In addition, zymography analysis revealed the inhibition of dentinal MMP-2 and -9 with 0.2% CHX blended within the adhesive formulation. Further in vivo studies are needed to confirm the potential benefits of CHX-containing adhesive systems. doi:10.1016/j.dental.2010.08.032 25 Proprietary solvent enhances dentin wettability P. Mehtälä 1 , K. Tjäderhane 1
Agee 2 , L.
Breschi 3 , D.H.
Pashley 2 , L.
1
University of Oulu, Oulu, Finland Medical College of Georgia, Augusta, USA 3 University of Trieste, Italy 2
Objectives: Surface treatment such as acid etching increases dentin surface energy. The higher the energy indicated by lower contact angles, the better the association of resin onto the dentin surface and into the hybrid layer. The aim of our study was to investigate the possibility that our proprietary solvent could further increase surface energy and improve wettability of acid etched dentin. Materials and methods: Mid-coronal dentin was exposed to proprietary solvent in increasing concentrations and contact angle was measured by means of sessile drop equilibrium contact angle, using contact angle/surface energy analyzer. LVDT (linear variable differential transformer) measurements were used to investigate test solvents ability to expand collagen matrix. Contact angle results were analyzed using one-way ANOVA and Tukey’s post hoc test. Results: Contact angle decreased as the concentration of our test solvent increased. LVDT measurements showed that increase in experimental solvent concentration resulted in diminished collagen matrix expansion (Table 1). Conclusions: Dentin surface energy correlates to its wettability and therefore plays an important role in adhesion. Higher surface energy leads to stronger association between
e13
d e n t a l m a t e r i a l s 2 6 S ( 2 0 1 0 ) e1–e84
Table 1 – Contact angle measured in degrees, collagen matrix expansion expressed as percentage of fully hydrated expanded matrix. Solvent (wt%) 0% ◦
Contact angle ( )
48 ± 1.3
1% a
44 ± 2.1
2% 36 ± 2
b
3%
4%
30 ± 1.4
c
d
5%
29 ± 1.7
d
25 ± 1.9e
Solvent (wt%) 5% Expansion of dried demineralized dentin
98% ± 2%
10%a 92.5%
a
20%
30%
40%
50%
84% ± 3%
78% ± 4%
70% ± 3%
66% ± 3%
Same superscripts letters indicate no statistically significant difference (p > 0.05). a 10% expansion extrapolated from 5% and 15% results.
adhesive and the dentin surface. LVDT results showed that collagen matrix did not expand more fully with the aid of the solvent. The change in contact angle may therefore be a result of improved infiltration into acid etched dentin. Such effect would be beneficial in maximizing monomer permeation into acid-etched dentin during bonding. doi:10.1016/j.dental.2010.08.033 26 The anti-MMP activity of benzalkonium chloride M.M. Mutluay 1 , A. Tezvergil-Mutluay 1 , K.A. Agee 2 , R.M. Carvalho 3 , A. Manso 4 , F.R. Tay 2 , B.-Y. Suh 4 , D.H. Pashley 2 1
University of Turku, Finland Medical College of Georgia, USA 3 University of Sao Paulo, Brazil 4 Bisco Inc., USA 2
similar trend. BAC inhibited matrix-bound MMPs between 55 and 66% when measured as mass loss or 76–81% when measured as solubilization of collagen peptide fragments. ANOVA showed significant effect of BAC compared to control (p < 0.05). Conclusions: BAC is very effective at inhibiting both soluble and matrix-bound dentine MMPs in the absence of resins. Supported, in part, by grants R01 DE015306-06 from the NIH/NIDCR (P.I. DP) and by the Finnish Academy (P.I. ATM). doi:10.1016/j.dental.2010.08.034 27 CHX-containing adhesive inhibits dentin MMPs: A zymographic assay F. Nato 1,2 , A. Mazzoni 2 , P. Gobbi 1 , M. Carrilho 3 , G. Mazzotti 2 , F.R. Tay 4 , D.H. Pashley 4 , L. Breschi 5 1
University of Urbino, Italy University of Bologna, Italy 3 UNIBAN, Brazil 4 Medical College of Georgia, USA 5 University of Trieste, Italy 2
Objectives: Matrix metalloproteinases (MMPs) bound to dentin are known to contribute to progressive degradation of collagen fibrils in hybrid layers. Inhibition of host-derived MMPs by quaternary ammonium compounds was shown to slow the degradation. Benzalkonium chloride is a cationic surface-acting agent belonging to the quaternary ammonium group of compounds and widely used for antibacterial properties. This study evaluated the ability of benzalkonium chloride (BAC) to inhibit soluble versus bound dentine matrix metalloproteinases (MMPs). Materials and methods: The inhibitory effects of four different BAC concentrations (0.5–5 wt%) on soluble rhMMP2, 8 and 9 were initially screened using a commercially available colorimetric assay kit. Matrix-bound endogenous MMP-activity was evaluated in completely demineralized beams using two different concentrations of BAC (0.5 and 1 wt%). Each beam was either dipped into BAC for 10 or 30 s and then dropped into 1 mL of an complete medium (CM) or alternatively they were placed in either 1 mL of CM containing BAC or only CM for 30 days (control). After 30 days, changes in the dry mass of the beams or in the hydroxyproline (HYP) content of hydrolyzates of the media were quantitated as indirect measures of matrix collagen hydrolysis. The data were analyzed using ANOVA, at ˛ = 0.05. Results: All tested BAC concentrations showed an inhibition of 93–100% and were highly effective (p < 0.05) in inhibiting soluble rhMMP-2, 8 or 9. Matrix-bound MMP model showed
Objectives: Matrix metalloproteases (MMPs) are a family of Zn- and Ca-dependent enzymes involved in several developmental and disease-associated processes. Since these enzymes have been suggested as playing key roles in the degradation of resin–dentin matrices, the use of chlorhexidine (CHX, a non-toxic MMP inhibitor) as additional primer during bonding procedures has been reported to be effective in the preservation of the hybrid layer over time. The purpose of this study was to identify the effectiveness of including CHX within the formulation of a self-etch adhesive system on MMP-2 and -9 activity by means of gelatin zymography. Materials and methods: Dentin powder was pulverized from freshly extracted human molars. Four lots of dentin powder were obtained and randomly assigned to the following treatment group: (1) mineralized dentin + Adper Easy Bond (AEB; 3M ESPE, St Paul, USA); (2) mineralized dentin + 0.2% CHX-containing AEB (experimental adhesive, 3M ESPE); (3) demineralized with 1% aqueous solution of H3 PO4 for 10 min; (4) untreated mineralized dentin (control). After rinsing in acetone to remove the uncured adhesive system, protein extracts obtained from the treated dentin powder were then electrophoresed by gelatin zymography, for detection of MMPs enzyme activity.