IADR Abstract Archives

Inactivation Of Dentin Proteases By Collagen Crosslinkers

Objectives: The poor durability of resin-dentin bonds created by contemporary adhesives is thought to be due, in part, to the enzymatic degradation of collagen by matrix metalloproteinases (MMP)s or cathepsine-K (CAT-K) in the hybrid layer. Biomodification of dentin by collagen crosslinkers should inactivate all dentin proteases simultaneously. The aim of this work was to evaluate the effect of various collagen crosslinking agents on dentin protease activity.

Methods: Demineralized dentin beams (1x2x6 mm) (n=10/group) were prepared from mid-coronal dentin. The initial and final dry mass was measured for all beams. Control beams were incubated in simulated body fluid (SBF, 1 mL); experimental beams were first dipped in specified crosslinkers (Table 1) for 5 min, rinsed and then incubated for 3 or 21 days. Aliquots of the incubation medium were used to analyze solubilized telopeptide fragments using ICTP-as an indicator of MMP-mediated degradation and CTX for CAT-K-mediated degradation. Additionally, to analyze initial and residual gelatinase activity in demineralized dentin, we measured gelatin zymography and in situ zymography assays. The loss of dry mass, ICTP and CTX release rates from all groups were analyzed separately by repeated-measures ANOVA, α=0.05. Results: The dry mass loss (%), ICTP (ng telopeptide/mg dry dentin) and CTX (pg telopeptide/mg dry dentin) after 3 or 21 days were:

Groups	Dry Mass Loss (%)		ICTP (ng/mg dentin)		CTX (pg/mg dentin)
Groups	3 days	21 days	3 days	21 days	3 days	21 days
GA1: 1% Glutaraldehyde (v/v)	-5.2±1.3^b	-16.4±1.3^Ω	9.3±0.2^b	10.3±1.5^Ω	125.3±32.8^b	173.7±36.5^¥
GA2: 5% Glutaraldehyde (v/v)	-1.7±1.4^b	-12.7±1.3^Ω	0.6±0.2^f	0.8±0.1^∑	14.0±2.9^c	19.2±4.7^∑
GS1:1%: Grape seed extract (w/v)	-3.4±1.1^b	-17.0±0.8^Ω	3.5±1.7^e	14.6±0.6^¥	23.0±8.3^c	234.7±52.9^¥
GS2: 5% Grape seed extract (w/v)	-1.2±1.0^c	-13.0±1.8^Ω	1.8±0.6^ef	8.6±0.2^Ω	14.7±5.3^c	70.0±14.1^∑
S: 10% Sumac berries extract (w/v)	-2.1±1.7^c	-15.6±1.2^Ω	7.7±1.1^c	16.3±1.7^¥	46.0±11.2^c	341.1±56.6^Ω
CR1: 20µM Curcumin (w/v)	-8.9±0.3^a	-12.9±1.8^Ω	5.4±0.4^d	9.4±0.0^Ω	12.4±1.8^c	12.4±2.2^∑
CR2: 200µM Curcumin (w/v)	-0.9±0.6^c	-6.9±2.0^¥	2.9±1.1^ef	0.7±0.1^∑	48.3±18.7^c	50.7±9.5^∑
CM: Control	-8.4±0.8^a	-32.1±5.9^†	17.7±0.7^a	29.0±3.5^†	207.5±66.5^a	589.1±130.2^†

Table 1: Values are shown by mean±SD. Groups with the same letter are not statistically significant (p > 0.05).

Conclusion: The results clearly show that dentin biomodification by collagen crosslinkers significantly reduced the protease activity in demineralized dentin matrices. Both gelatin and in situ zymographic analyses revealed that all crosslinkers inhibited dentinal gelatinases. Dentin biomodification by use of collagen crosslinkers seems to be a promising approach to increase the durability of resin dentin bonds.

Division: IADR/AMER General Session
Meeting: 2014 IADR/AMER General Session (Cape Town, South Africa)
Location: Cape Town, South Africa
Year: 2014
Final Presentation ID: 895
Abstract Category|Abstract Category(s): IADR/Unilever Hatton Awards

Authors

Seseogullari-dirihan, Roda ( FINDOS, University of Turku, Turku, , Finland )

Apolonio, Fabianni ( Universidade Federal Do Ceara, Fortaleza, N/A, Brazil )

Mazzoni, Annalisa ( University of Trieste, Trieste, , Italy )

Tjaderhane, Leo ( University of Oulu, Oulu, N/A, Finland )

Breschi, Lorenzo ( DIBINEM University of Bologna, Bologna, , Italy )

Pashley, David ( Georgia Regents University, Augusta, GA, USA )

Tezvergil-mutluay, Arzu ( University of Turku, Turku, , Finland )

SESSION INFORMATION

Poster Session
Senior-Basic Science
06/27/2014