Effect of cigarette smoking on the color stability and surface roughness of two different denture base materials.

PURPOSE

To evaluate the effect of cigarette smoking on the color stability and surface roughness of heat-polymerized poly(methylmethacrylate) (PMMA) and computer-aided design and computer-aided manufacturing (CAD-CAM) PMMA denture base materials.

METHODS

A total of 40 disc-shaped specimens (diameter 15 mm x thickness 2 mm) were divided into two groups according to their processing technique: Group CC, CAD-CAM PMMA; and Group HP, heat-polymerized PMMA. The specimens were exposed to cigarette smoke with 20 cigarettes daily for 5 days. Before the procedure, the color of the denture base was measured using a spectrophotometer in accordance with the Commission Internationale de I'Eclairage (CIE) color system. The surface roughness (Ra) of each sample was measured five times before and after exposure to smoke using a profilometer, and the mean roughness (Ra) values were calculated. The color change and surface roughness were statistically analyzed (P< 0.05).

RESULTS

Greater discoloration was observed in the HP group, whereas the CC group showed clinically acceptable color change. Smoking increased the surface roughness of both denture base materials. However, the HP group had higher mean values than the CC group.

CLINICAL SIGNIFICANCE

Denture base materials are susceptible to changes in color and surface roughness due to oral habits such as cigarette smoking. This in vitro study suggested that smoking can exacerbate the color changes and surface roughness of denture base materials, especially in heat-cured acrylic resins.