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Biomedical subjects

J Kanca

Publications and source records attributed to J Kanca.

At least 19 recordsLinked to original sources
PubMed2001

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Composite Resins↗
PubMed1999

Pulse activation: reducing resin-based composite contraction stresses at the enamel cavosurface margins.

PURPOSE: To evaluate the effect of pulse activation light-curing of resin-based composites on the stress reduction at the enamel surface. MATERIALS AND METHODS: The rate of polymerization of a resin-based composite known to be accompanied by high contraction stress was examined by its surface hardness. The effects of polymerization stresses were examined with the use of dye penetration along enamel margins in cavities with a C-factor of 5. The occlusal-most layer of resin-based composite was polymerized at different power densities and time intervals; 40 s@600 mW/cm2, 40 s@100 mW/cm2 and pulse activation; 2 s@300-350 mW/cm2, followed by additional exposure of 10 s@600 mW/cm2. Diametral tensile strengths were measured for each parameter. RESULTS: The surface hardnesses of both the 40 s@600 mW/cm2 group and the 40 s@100 mW/cm2 group developed at nearly the same rate. The surface hardness of the pulse activated group developed appreciably slower. The diametral tensile strengths of all three groups were not significantly different. There was significantly less dye penetration with the use of the lower power density but there was very little leakage noted with the pulse-activated group. It is believed that this is the result of a prolonged gel state, which allowed flow to occur in the resin-based composite. There is significant clinical potential for the use of pulse activation of light-cured resin-based composite materials.

Composite Resins↗
PubMed1998

Bonding to dentin. Clues to the mechanism of adhesion.

PURPOSE: To investigate the effect on shear bond strength of the presence or absence of the demineralized collagen layer on both wet and dried etched dentin surfaces. MATERIALS AND METHODS: Composite cylinders were mounted on dentin surfaces after the following treatments; 37% etch/wet, 37% etch/dry, 37% etch/NaOCl/wet, 37% etch/NaOCl/dry, No-etch/wet, No-etch/dry, No-etch/NaOCl/wet, No-etch/NaOCl/dry. 24-hr shear bond strength data was obtained. SEM examinations of various surfaces were also conducted. RESULTS: Wet bonded specimens had significantly higher shear bond strengths, with or without the presence of the demineralized collagen layer, whether they were acid-treated or not. Acid-etched specimens had significantly higher shear bond strengths than unetched specimens.

Acid Etching, Dental↗
PubMed1997

One step bond strength to enamel and dentin.

PURPOSE: To evaluate the shear bond strength over a variety of conditions of a new dental adhesive having the primer and bonding resin in a single bottle. MATERIALS AND METHODS: Facial surfaces of extracted human molars for the dentin study and labial surfaces of incisors were treated with the One-Step adhesive after both etching and nonetching, variable etching times and variable rinsing times. Composite cylinders were attached and shear bond strengths were obtained. RESULTS: The bond strength data was quite consistent over a wide variety of conditions. The bond strengths were in the range of 23-29 MPa to dentin, and compared favorably with the performance of the adhesive to etched enamel surfaces.

Acid Etching, Dental↗
PubMed1996

Replacement of a fractured incisor fragment over pulpal exposure: a long-term case report.

This article presents the long-term follow-up of a patient in whom an incisor that had been fractured through the pulp was replaced with the original tooth fragment. In the replacement process, the enamel, dentin, and pulp were acid etched and bonded as part of the restoration protocol. More than 5 years have passed since the original treatment, and the treatment has thus far been a success.

Adolescent↗
PubMed1996

Wet bonding: effect of drying time and distance.

PURPOSE: To examine the effect of various drying times and air syringe-to-tooth distances on the shear bond strength of a dentin adhesive that requires a wet surface for maximum effectiveness. MATERIALS AND METHODS: Seventy extracted human molars were acid etched. The surface of the etched dentin was rinsed and dried with compressed air for 1, 3, or 5 seconds from a distance from either a distance of 1 or 10 cm. The adhesive One-Step was then applied, composite cylinders were attached and shear bond strengths were obtained. RESULTS: Drying time and distance had a significant impact on the resultant shear bond strengths. Longer drying times and shorter syringe-to-tooth distances negatively affected the bond strength of the adhesive studied.

Acid Etching, Dental↗
PubMed1994

Adhesion to enamel, dentin, metal, and porcelain.

Adhesion has an inseparable association with cosmetic dentistry. The ability to bond well to tooth structure has allowed the placement of countless porcelain veneers and many ceramic inlays and onlays. Improved materials and techniques have offered clinicians the ability to place these restorations with skill and reliability. The past year has seen many developments and additions to the armamentarium of the cosmetic dentist. The compiled data have been placed in different sections to facilitate the learning process. Review of the following material will familiarize the clinician with the current state of the art in the adhesive aspect of cosmetic dentistry. The ability to employ adhesive techniques has revolutionized the practice of dentistry. Clinicians have at their command materials that allow the placement of thin pieces of ceramic onto tooth structure without shattering, the routine placement of composite materials into posterior teeth, the diminishing reliance on liners and bases, and lessened postoperative discomfort with the use of dentin bonding systems. It is, as previously noted, useful to separate the analyses of adhesion to each of the substrates. Advances continue to be made in each of these areas that although not necessarily facilitating treatment ease, improve the reliability of the procedure. This review attempts to highlight the significant literature of the previous year.

Dental Alloys↗
PubMed1993

Etchant composition and bond strength to dentin.

This in vitro study examined the effects of three different types of acid etchants on the bond strengths of three dentin bonding systems. The etchant free of both silica and oxalate provided the highest bond strengths for all three systems. Use of the etchant containing oxalate resulted on the lowest bond strengths for all three systems. It is suggested that bond strengths vary as a consequence of deposition onto the dentin surface of various minerals or salts found in the etchants. It is recommended that if treatment of dentin with acids is indicated it should probably be done with those etchants containing neither silica nor oxalate.

Acid Etching, Dental↗
PubMed1993

Replacement of a fractured incisor fragment over pulpal exposure: a case report.

This paper is a clinical report demonstrating reattachment of a fractured incisor fragment. The fragment was replaced without the use of a filled composite resin, because the fracture had little splintering of the edges of the opposing pieces. Frank pulpal exposure was treated by an acid-etching procedure, wet bonding and surface disinfection prior to sealing of the wound site. At 1 year, the tooth is vital and has remained totally asymptomatic.

Adolescent↗
PubMed1992

Resin bonding to wet substrate. II. Bonding to enamel.

In part I of this study, it was reported that high shear bond strengths to dentin were obtained by using a particular dentin-enamel bonding system on wet dentin. Because it would be difficult to dry the enamel without drying the dentin, an investigation was undertaken to determine if the treatment of enamel surfaces with various phosphoric acid concentrations would be successful on wet enamel using the same bonding system. It was discovered that the bond strengths to etched and wet enamel using a particular dentin-enamel bonding system were equal to or higher than bond strengths to etched and dry enamel.

Composite Resins↗
PubMed1992

Effect of resin primer solvents and surface wetness on resin composite bond strength to dentin.

This study investigated the effect of various solvents on resin composite bond strength to dentin with both wet and dry dentin. A generic dentin bonding system was created with HEMA as the resin in the primer. The highest bond strengths were obtained when acetone was used as the solvent on a wet dentin surface; the lowest bond strengths were obtained with water as the solvent and the primer placed on a wet dentin surface.

Acetone↗
PubMed1992

Interfacial morphology of resin composite and shiny erosion lesions.

Ten shiny erosion lesions were divided horizontally, in vivo such that the gingival half was prepared and the incisal half remained unprepared. Both were etched simultaneously with 32% H3PO4 for 20 seconds, rinsed and restored using the All Bond wet technique and P50 composite. The teeth, which were extracted as part of a treatment plan, were sectioned vertically midway through the restorations. Polyvinyl siloxane impressions of the tooth/resin interface were taken and examined by SEM for the presence of gaps. The teeth were then demineralized and the fitting surfaces of the restorations were examined for resin penetration into the dentin. Results showed that there were no gaps present in any of the interfaces. The most proliferative and deep resin penetration occurred in the prepared/etched halves.

Bisphenol A-Glycidyl Methacrylate↗