Impact of Smokeless Tobacco on the Color Stability of Zirconia, Zirconia-Reinforced Lithium Silicate and Feldspathic CAD/CAM Restorative Materials: An In Vitro Study

Abstract

WHO estimates that the global number of tobacco users exceeds 1.3 billion people. Few studies have examined the effect of locally made smokeless tobacco (ST) products on the color changes of material used in dental prosthetics. Bearing the recent advances in CAD/CAM ceramic restorations material in mind, this study aimed to assess ST influence on mean color change (∆E*) values among selected CAD/CAM ceramic types: multilayer zirconia (Ceramill Zolid PS), zirconia-reinforced lithium silicate ceramic (Vita Suprinity), and feldspathic (Vita TriLuxe) restorative materials. The color changes of the ceramics were compared to VITA classical and VITA 3D-MASTER shade guides. Sixty CAD/CAM ceramic specimens (20 samples each) were fabricated from Ceramill Zolid PS, Vita TriLuxe Forte, and VITA Suprinity. Specimens were prepared and divided into two groups according to the ST type and immersed for two weeks. Basic VITA classical and VITA 3D-MASTER colors were recorded at a baseline of one week and two weeks. The highest ∆E* values were recorded in the black ST for Vita Suprinity (4.77) in the first week, followed by Vita TriLuxe (4.07) in the second week. For white ST, Vita TriLuxe (4.87), and Vita Suprinity (4.42) showed extensive color change after two weeks and one week, respectively. The color change was least in zirconia for black and white ST after one week. CAD/CAM ceramic materials showed no significant difference after 1 and 2 weeks for the tested ST types. The effects of ST on CAD/CAM ceramic material (∆E* values) were high but did not reach clinically unacceptable values. Zirconia showed the least amount of color change among all the tested materials.

Effect of Thermocycling on Color, Surface Characteristics, Compressive Fracture, and Fracture Modes of Prosthetic CAD/CAM Ceramics After Smokeless Tobacco Immersion

“…Prosthetic CAD/CAM dental ceramics have become a tremendously significant material in day-to-day prosthesis manufacturing because of their numerous advantages, such as long clinical survival rate, good translucency, durability, biocompatibility, color brightness, and intensity properties as natural non-stained teeth, and excellent long-term esthetic qualities [ 1 , 2 ]. As a consequence of continuing improvements, several materials have been utilized to fabricate ceramic prosthesis; these materials include hybrid polymer-infiltrated feldspathic ceramic-network material (VE), leucite-containing feldspathic glass (Vitablocs ® Mark II), and zirconia-reinforced lithium silicate (VS) CAD/CAM prosthetic ceramics [ 1 , 3 – 5 ]. For a number of years, feldspathic prostheses have been the most widely used restorative material in the esthetic zone due to clinical longevity and the accepted aesthetics of restoration [ 4 , 5 ].…”

“…As a consequence of continuing improvements, several materials have been utilized to fabricate ceramic prosthesis; these materials include hybrid polymer-infiltrated feldspathic ceramic-network material (VE), leucite-containing feldspathic glass (Vitablocs ® Mark II), and zirconia-reinforced lithium silicate (VS) CAD/CAM prosthetic ceramics [ 1 , 3 – 5 ]. For a number of years, feldspathic prostheses have been the most widely used restorative material in the esthetic zone due to clinical longevity and the accepted aesthetics of restoration [ 4 , 5 ]. Currently, in modern dental practice, zircon-based ceramic is considered one of the most popular materials to construct ceramic prostheses [ 6 – 8 ], due to its superior mechanical properties and excellent biocompatibility compared with other dental ceramics [ 9 – 11 ].…”

“…In addition, it is largely manmade, prepared by crushing of the tobacco along with ash, oils, calcium oxide, flavors, and black pepper [ 15 ]. ST is widespread in southern regions of Saudi Arabia (Khameis Moushiet, Najran, and Jazan), where it is used orally or nasally [ 5 , 14 , 15 ]. In these regions of Saudi Arabia, ST use is observed in individuals as young as 13–17 years old [ 13 , 14 ].…”

“…In these regions of Saudi Arabia, ST use is observed in individuals as young as 13–17 years old [ 13 , 14 ]. Mostly, these products are habitually positioned in the mouth (vestibule) for a duration between 7–15 min [ 5 , 13 – 15 ]. Alkhatib reported that, similar to cigarette smokers, ST users exhibit brown discoloration of their upper and lower frontal teeth (area of the positioning of ST) [ 16 ].…”

“…The dissimilarity of microstructures has an important effect on the clinical performance of these materials. A profilometer device, which measures Ra and Rz, is a useful device for quantifying the microstructure and assessment of the surfaces of ceramic specimens [ 5 , 20 , 23 ]. Thermocycling (TC) is a popular method of artificial accelerated aging of ceramics because it reproduces the oral environment as an extrinsic factor [ 24 – 26 ].…”