Aim: Compositional modification of conventional glass ionomer luting cements by incorporating two types of all-ceramic powders in varying concentrations and evaluation of their film thickness, setting time, and strength. Material & Methods. Experimental GICs were prepared by adding different concentrations of two all-ceramic powders (5%, 10, and 15% by weight) to the powder of the glass ionomer luting cements, and their setting time, film thickness, and compressive strength were determined. The Differential Scanning Calorimetry analysis was done to evaluate the kinetics of the setting reaction of the samples. The average particle size of the all-ceramic and glass ionomer powders was determined with the help of a particle size analyzer.

Results: A significant increase in strength was observed in experimental GICs containing 10% all-ceramic powders. The experimental GICs with 5% all-ceramic powders showed no improvement in strength, whereas those containing 15% all-ceramic powders exhibited a marked decrease in strength. Setting time of all experimental GICs progressively increased with increasing concentration of all-ceramic powders. Film thickness of all experimental GICs was much higher than the recommended value for clinical application.

Methods: The posterior parts of the archwires were sectioned into 20 mm segments (N = 102) and divided among six groups. Four groups were treated with different pH levels and two served as controls. The specimens were immersed in individual test tubes containing 10 ml of artificial saliva adjusted to a pH of 6.75 or 3.5. The tubes were sealed and stored in a 37 °C water bath for 28 days. After 28 days, the specimens were ligated to brackets embedded in an acrylic block and subjected to mechanical stress using an electronic toothbrush for 210 s. The specimens were photographed, and images were measured for coating loss using AutoCAD® software. Surface morphology was observed using a scanning electron microscope (SEM).

MATERIALS AND METHODS: Using a stainless-steel mold, disc-shaped wax patterns with dimensions of 10 mm in diameter and 2 mm thick (in accordance with ADA Specification No. 12) were created and prepared for a total of 75 acrylic samples. Dimensions of all 75 acrylic samples were checked with a digital Vernier caliper. About 25 samples of denture base material were immersed in three different chemical disinfectants: Group I: immersed in chlorhexidine gluconate solution, group II: immersed in sodium hypochlorite solution, and group III: immersed in glutaraldehyde solution. All samples were scrubbed daily for 1 minute with the appropriate disinfectant and submerged for 10 minutes in the same disinfectant. Between disinfection cycles, samples were kept in distilled water at 37°C. Color stability was measured using a reflection spectrophotometer. Surface roughness values were measured by a profilometer at baseline following 15 days and 30 days.

RESULTS: After 15 days, the color stability was better in chlorhexidine gluconate solution group (4.88 ± 0.24) than sodium hypochlorite solution (4.74 ± 0.18) and glutaraldehyde solution group (4.46 ± 0.16). The mean surface roughness was less in glutaraldehyde solution group (2.10 ± 0.19), followed by chlorhexidine gluconate solution group (2.48 ± 0.09) and sodium hypochlorite solution group (2.64 ± 0.03). After 30 days, the color stability was significantly better in chlorhexidine gluconate solution group (4.40 ± 0.02), followed by sodium hypochlorite solution (4.06 ± 0.16) and glutaraldehyde solution group (3.87 ± 0.17). The mean surface roughness was significantly lesser in glutaraldehyde solution group (2.41 ± 0.14), followed by chlorhexidine gluconate solution group (2.94 ± 0.08) and sodium hypochlorite solution group (3.02 ± 0.13).

CONCLUSION: In conclusion, the color stability was significantly better in chlorhexidine gluconate solution group than sodium hypochlorite solution and glutaraldehyde solution group. But the surface roughness was significantly lesser in the glutaraldehyde solution group, followed by the chlorhexidine gluconate and sodium hypochlorite solution group.