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Biomedical subjects

W J Finger

Publications and source records attributed to W J Finger.

47 records · Page 3Linked to original sources
PubMed1991

Dentin surface reproduction with hydrophilic and hydrophobic impression materials.

The detail reproduction of ground moist dentin surfaces with hydrophilic and hydrophobic elastomeric impression materials and the transfer of details onto stone casts produced from such impressions were investigated. Practically no difference was found in the detail-reproducing ability of the six impression materials and that of the dies produced therefrom. The surface roughness data were not related to the degree of hydrophilicity determined as the contact angle between water and impression material in spite of the considerable variation in contact angles of the six materials investigated. The critical surface tension of an experimental low-viscosity vinyl polysiloxane material of typical composition was 22.2 and 22.9 mN/m in the uncured and cured state, respectively. The contact angle between water and this compound was 105 degrees. The critical surface tension of wet dentin is reported to be 45.1 mN/m (Glantz, 1969), which means that the experimental impression paste will spread on wet dentin in spite of the pronounced hydrophobicity of the set product.

Analysis of Variance↗
PubMed1991

Shelf life of the Gluma bonding system.

The objective of this study was to determine by shear bond strength testing the efficacy of Gluma batches produced between 1985 and 1990 and stored at either 23 degrees C or varying temperatures between 19 degrees and 32 degrees C. The average bond strength figures for the thirty variable conditions tested were not significantly different from each other on the 0.05 significance level. Chemical analysis of the individual Gluma Primer batches investigated proved that the concentration of the main active ingredients of the mixture, glutaraldehyde and HEMA, were not or only moderately reduced when compared with the composition determined on the dates of manufacture. It was concluded that this bonding system is stable over a period of 6 years when possible extremes in storage temperature are avoided.

Analysis of Variance↗
PubMed1989

Dentin surface roughness vs. bond strength of dentin adhesives.

The effects of differently prepared dentin surfaces on the bond strength mediated by five dentin adhesive/composite resin systems were investigated: Clearfil new bond/Clearfil Ray, Gluma/Lumifor, Scotchbond/Silux, Scotchbond 2/Valux, and Tenure/Silux. Bonding surfaces were produced either by wet-grinding of human teeth on SiC paper, grits 180, 240, 320, 400, 600, and 4000, respectively, or by cutting them with dental preparation instruments. The surfaces of the dentin were analyzed by a profilometer. Tensile bond strengths (TBS) were determined two min after light activation of the restorative systems. In spite of greatly different effective areas for bonding, ANOVA showed no significant differences on the 5% level between the TBS means of one material system recorded for the different dentin preparations. It was concluded that the dentin roughness produced by preparation has no significant influence on early bond strengths of bonding composite resin systems.

Dental Bonding↗
PubMedDate not supplied

Principles and mechanisms of bonding with dentin adhesive materials.

This article reviews six dentin bonding agents with regard to composition of the individual components of each of the systems. Adhesion mechanisms are discussed relative to the chemical compounds mediating the bond. Adjunctly, inspection of the bonding sites between the different adhesives and human dentin by scanning electron microscopy elucidates the bonds formed as far as detail reproduction as an indicator for wetting ability or mechanical interlocking.

Composite Resins↗
PubMedDate not supplied

Effect of mode of conditioning treatment on efficacy of dentin bonding.

The effect of the mode of application of the Gluma bonding systems' conditioning agents on dentin bonding efficacy was investigated. The reason for this study was the apparent conflict between the manufacturer's instruction to rub the cavity for 30 seconds with a pellet soaked with the conditioning agent and the poor access to some cavity types, which may make it impossible to do so. The efficacy of dentin bonding with or without rubbing conditioning was not different in terms of shear bond strength and marginal cavity adaptation. SEM analysis of the coupling zone showed different resin-impregnated layer thicknesses resulting from the two modes of conditioning. These differences have, however, no impact on the quality of the bond mediated, provided that, as with the Gluma bonding systems, the primer and/or the adhesive resin have perfectly wetted and penetrated the surface collagen and that the degree of polymerization of the resin in the coupling hybrid layer is adequate. The mode of conditioning, therefore, is not critical for dentin bonding with the Gluma systems.

Acid Etching, Dental↗
PubMedDate not supplied

Enamel and dentin bond strength and bonding mechanism to dentin of Gluma CPS to primary teeth.

This study evaluated the shear bond strength to enamel and dentin and bonding mechanism to dentin of Gluma CPS bonding system to primary teeth enamel and dentin. Pekafill hybrid composite was used. Ten specimens were immersed in deionized water at 37 degrees C for twenty-four hours and ten other specimens were subjected to a thermocycling procedure (2000 cycles between 5 degrees and 55 degrees C, dwell time fifteen seconds). After water storage or thermocycling, the bonded cylinders were sheared and the bond strength calculated. After debonding, the failure sites of all samples were evaluated microscopically. The data were analyzed with an ANOVA and Student-Newman-Keuls test. In ten other primary molars, the buccal surfaces were ground flat on wet SiC papers to expose peripheral dentin. Cylindrical buttjoint cavities were prepared with a cylindrical diamond bur. The cavities were treated with Gluma CPS and filled with pekafill as described above. After fifteen-minute water storage, filling excess was removed and marginal integrity and bonding mechanism of five restorations was examined with a light microscope. Five other restorations were evaluated after storage in water at 37 degrees C for twenty-four hours. Maximal gap widths and hybrid layer thickness were determined. The results showed that thermocycling did not affect the shear bond strength to enamel or dentin. There was a statistically significant difference (p < 0.05) between the shear bond strength values obtained in enamel and dentin. The maximal gap width was not significantly different between specimens that were stored in water for fifteen minutes or twenty-four hours. The average hybrid layer thickness was 11.7 +/- 1.1 micrograms. All specimens revealed a resin cohesive failure very close to enamel or dentin surface. The etch patterns produced on the abraded enamel surface were uniform and deeper as compared to the sample that was pumiced. This was also confirmed in the epoxy replicas.

Acid Etching, Dental↗