Mechanical stability and proteolytic activity of resin-dentin bonds produced by the cross-linked dry bonding technique

Author(s)

Mariana Citta

• Document type: Master's Dissertation
• Press: Araraquara. 2019-03-28.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Odontologia. Araraquara
• Defense date: 2019-03-01
• Advisor: Josimeri Hebling

Abstract

Objective: To evaluate the mechanical stability and the proteolytic activity of bonds created by a one-step, etch-and-rinse adhesive applied to cross-linked and air-dried etched dentin. Methods: Flat coronal dentin surfaces were produced in 64 sound molars. The teeth were divided into 4 groups according to the solution applied on the etched dentin: 5% grape seed extract, 5% glutaraldehyde, Gluma Desensitizer or deionized water (control). Solutions were applied for 60s followed by rinse and blot drying. Then, the teeth were separated into two subgroups: the etched dentin was kept moist or air dried for 60s. Optibond was applied followed by a composite resin buildup. After 24h, the teeth were cut into beams (0.81 mm²) which were microtensile tested immediately or after 12mo of storage. Additional teeth (n=32) were bonded as described and cut into 0.5 mm-thick slabs. The slabs were prepared for nanoleakage and in situ zymography analyses (EnzChek). Bond strength data were submitted to ANOVA and Tukey tests (p<0.05) while nanoleakage and zymography data were descriptively reported. Results: Significant reduction in bond strength (ca. 65%) and increase of the proteolytic activity was seen when the etched dentin was air-dried without previous biomodification. Conversely, bond strengths did not differ from those produced on wet dentin when collagen was cross-linked before air-drying, irrespective of the solution. For both moist and air-dried etched dentin, collagen cross-linking resulted in mechanically stable bonds and reduced proteolytic activity. Conclusion: Bonds produced by the application of a one-step, etch-and-rinse adhesive to cross-linked, air-dried etched dentin became mechanically stable and revealed reduced proteolytic activity after one year of aging. (AU)

• FAPESP's process: 17/03927-9 - Mechanical stability and proteolytic activity of the resin-dentin bond produced using the cross-linked dry technique
• Grantee: Mariana Citta
• Support Opportunities: Scholarships in Brazil - Master