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B Rhodes

Publications and source records attributed to B Rhodes.

27 records · Page 2Linked to original sources
PubMedDate not supplied

Retentive strength of an amalgam bonding agent: chemical vs light vs dual curing.

Dentin bonding agents have been shown to enhance retention of amalgam restorations by mechanical means. Little research is available on which mode of curing may optimize amalgam bonding. This in vitro study compared the bond strengths exhibited by three variations of a bonding agent, each using a different curing mode, with two earlier versions of amalgam resin liners and cavity varnish. The six test groups of lining agents for amalgam restorations included [C] chemical-cured, [L] light-cured and [D] dual-cured versions of one filled adhesive resin (Clearfil Liner Bond 2V), [LF] Light-cured, Filled resin (Clearfil Liner Bond 2, Kuraray Co.); [LCF] Light- and Chemical-cured, Filled resin Clearfil Liner Bond + Protect Liner, Kuraray Co) and [V] Varnish (Copalite, Cooley & Cooley, Ltd). For each group, 20 Class V cavity preparations were cut in human molars. The preparations were 2.5 mm deep and 3 mm wide at the pulpal floor, with a slightly divergent taper. After treating the preparation with the bonding agent, a 3/4 inch, 18 gauge flat-headed wire nail was seated in the cavity with its head at the pulpal floor of the preparation, and Tytin amalgam (Kerr Corp, Romulus, MI) was condensed into the preparation around the nail. All restorations were stored for 24 hours in distilled water at 37 degrees C, then subjected to 2500 thermal cycles (8 degrees C to 58 degrees C). After one week the samples were tested to failure in tension using an Instron Universal Testing Machine (crosshead speed = 2 mm/min) and peak load (kg) was recorded. Significant differences in retention were found using ANOVA and the Games & Howell post hoc test (p = 0.05). The mean loads at failure (+/- SD) were C 13.1 (+/- 2.4), L 21.8 (+/- 6.1), D 26.8 (+/- 7.4), LCF 23.8 (+/- 7.4), LF 21.4 (+/- 3.3) and V 2.0 (+/- 1.8). All dentin-bonding agents exhibited significantly greater retention than the varnish. While the bond strengths of the dual cured (D) and the light-cured (L) liners were not significantly different from one another, both were significantly higher than the chemically-cured (C) resin liner in terms of retention.

Analysis of Variance↗
PubMedDate not supplied

The effect of double adhesive application on the shear bond strength to dentin of compomers using three one-bottle adhesive systems.

The development of one-bottle dentin adhesive systems resulted in much optimism about providing simplified predictable esthetic dentistry. However, laboratory testing of these systems continues to provide significant variations between facilities. A potential effect of the number of applications was noted in this author's laboratory. This study evaluated the effect of doubling the manufacturer's recommended number of applications on shear bond strength to dentin. Ninety human molars were divided into groups of 15. The occlusal surfaces were finished to 600 grit SiC to provide a flat dentin bonding surface. Prime & Bond NT-Dyract, Optibond Solo-Elan and One Step-Dyract were evaluated. Each material was tested using: (1) the recommended number of adhesive applications and (2) twice the number of applications recommended. All adhesive applications were accomplished before light curing the adhesive. The specimens were thermocycled after one week of storage and tested in shear after two weeks. Specimens were also fabricated after adding Rhodamine D to the adhesive to allow for visualization using confocal microscopy. These teeth were sectioned and viewed 24 hours after fabrication. A t-test was used to compare differences within product groups. The results showed a significant effect (p < 0.001) when a double application of Prime & Bond NT was used. No difference was seen with Optibond Solo or One Step. All specimens appeared to have a uniform, glossy appearance of adhesive during fabrication. Therefore, the appearance of the adhesive after application may not be a reliable predictor of acceptable bonding. Confocal microscopy showed that single application Prime & Bond NT specimens did not exhibit a uniform thickness of adhesive across the entire interface. Tubule penetration and hybridization was apparent for all specimens.

Bisphenol A-Glycidyl Methacrylate↗
PubMedDate not supplied

Microleakage of high-strength glass ionomer: resin composite restorations in minimally invasive treatment.

Atraumatic Restorative Treatment (ART) has been investigated as an alternative caries treatment. The technique involves removal of loose tooth structure with a spoon excavator, followed by placement of an adhesive restorative material, often a high-strength glass ionomer. This study compares the microleakage of a high-strength glass ionomer/resin composite and two occlusal resin composite restoration techniques.

Acid Etching, Dental↗
PubMedDate not supplied

Comparison of retentiveness of amalgam bonding agent types.

Previous studies on amalgam bonded restorations indicated that amalgam bonding agents increased the bond strength of amalgam to tooth structure. This in vitro study was designed to compare how the mode of curing and the presence of filler in the resin would affect the bond strength of amalgam. The five test groups of lining agents for amalgam restorations included Chemical-cured, Unfilled resin (CU-Clearfil New Bond); Light-cured, Unfilled resin with a delayed chemical-cure property (LU*-Clearfil Photo Bond); Light-cured, Filled resin with a delayed chemical-cure property (LF*-Clearfil Photo Bond + Protect Liner); Dual-cured, Unfilled resin (DU-All-Bond 2); and Varnish (V-Copalite). For each group, 20 class 5 cavity preparations were cut on the facial, lingual, or proximal surfaces of human molars, which were embedded in acrylic resin. The preparations were 2.5 mm deep and 3 mm wide at the pulpal floor with a slightly divergent taper. After treating the preparation with the bonding agent, a 3/4-inch, 18-gauge flat-headed wire nail was placed into the cavity with the head at the pulpal floor of the preparation, and Tytin amalgam was then condensed into the preparation around the nail. The restorations were stored for 24 hours in distilled water at 37 degrees C and then subjected to 2500 thermal cycles (8 degrees C to 48 degrees C). After 1 week, specimens were tested to failure in tension using an Instron Universal Testing Machine (crosshead speed = 2 mm/min) and peak load (kg) was recorded. The mean loads at failure (+/- SD) were LF* 26.4 (+/- 7.0), DU 23.9 (+/- 6.4), LU* 16.0 (+/- 3.1), CU 14.3 (+/- 8.0), and V 9.5 (+/- 5.6). Significant differences were found using a one-way ANOVA and the Games and Howell post hoc test at a significance level of alpha = 0.05. The LF* and DU groups were not significantly different from each other, but they were significantly higher in peak load than all other groups. LU* was significantly higher than the varnish (V) but not significantly higher than CU. CU was not significantly higher than the varnish (V). The adhesives forming a thicker resin interface (the light-cured resin with filled resin liner and the dual-cured unfilled resin) demonstrated significantly greater retention than the light-cured unfilled resin, chemical-cured unfilled resin, and the varnish control.

Adhesiveness↗