An ultrastructural study of bonding to dentin smear layers

Abstract no. 998published_or_final_versio

The use of oxalate to reduce dentin permeability under adhesive restorations

Abstract no. 1705published_or_final_versio

Effect of smear layers on bonding of a self-etching primer to dentin

Abstract no. 1702published_or_final_versio

Solvation of dried dentin matrix by water and other polar solvents

Abstract no. 2022published_or_final_versio

Solvent and water retention in dental adhesive films after evaporation

published_or_final_versio

Tensile properties of demineralized dentin matrix after 48 months

Abstract no. 844published_or_final_versio

Solvent and water retention in dental adhesive blends after evaporation

This study examined the extent of organic solvent and water retention in comonomer blends with different hydrophilicity (Hoy's solubility parameter for hydrogen bonding, δh) after solvent evaporation, and the extent of tracer penetration in polymerised films prepared from these resins. For each comonomer blend, adhesive/solvent mixtures were prepared by addition of (1) 50 wt% acetone, (2) 50 wt% ethanol, (3) 30 wt% acetone and 20 wt% water and (4) 30 wt% ethanol and 20 wt% water. The mixtures were placed in glass wells and evaporated for 30-60 s for acetone-based resins, and 60-120 s for ethanol-based resins. The weight of the comonomer mixtures was measured before and after solvent evaporation. Resin films were prepared for transmission electron microscopy (TEM) after immersion in ammonical silver nitrate. The percentages of solvent and water retained in the comonomer mixtures, and between the acetone and ethanol groups were measured gravimetrically and were statistically compared. In comonomer-organic solvent mixtures, the percentage of solvent retained in acetone and ethanol-based mixtures increased significantly with hydrophilicity of the comonomer blends (P<0.05). In resin-organic solvent-water mixtures, significantly more solvent and water were retained in the ethanol-based mixtures (P<0.0001), when compared to acetone-based mixtures after 60 s of air-drying. TEM revealed residual water being trapped as droplets in resin films containing acetone and water. Water-filled channels were seen along the film periphery of all groups and throughout the entire resin films containing ethanol and water. The addition of water to comonomer-ethanol mixtures results in increased retention of both ethanol and water because both solvents can hydrogen bond to the monomers. © 2005 Elsevier Ltd. All rights reserved.postprin

Solvent-induced expansion of dried-demineralized dentin matrix

Abstract no. 249published_or_final_versio

Collagen degradation by host-derived enzymes during aging

Incompletely infiltrated collagen fibrils in acid-etched dentin are susceptible to degradation. We hypothesize that degradation can occur in the absence of bacteria. Partially demineralized collagen matrices (DCMs) prepared from human dentin were stored in artificial saliva. Control specimens were stored in artificial saliva containing proteolytic enzyme inhibitors, or pure mineral oil. We retrieved them at 24 hrs, 90 and 250 days to examine the extent of degradation of DCM. In the 24-hour experimental and 90- and 250-day control specimens, we observed 5- to 6-μm-thick layers of DCM containing banded collagen fibrils. DCMs were almost completely destroyed in the 250-day experimental specimens, but not when incubated with enzyme inhibitors or mineral oil. Functional enzyme analysis of dentin powder revealed low levels of collagenolytic activity that was inhibited by protease inhibitors or 0.2% chlorhexidine. We hypothesize that collagen degradation occurred over time, via host-derived matrix metalloproteinases that are released slowly over time.published_or_final_versio