An In Vitro Acidic Media Simulation of GERD And Its Effect on Machine-Milled Ceramics' Optical Properties

Introduction: This study will focus on how the color and translucency of indirect computer-aided design and computer-aided milling (CAD/CAM) ceramic restorations are affected by gastric acid, like erosive solution exposure.
Methodology: Four types of CAD/CAM ceramic materials were grouped as follows: group Z, Ceramill Zolid Gen-x white (Austria); group E, IPS e.max CAD HT A3 (Ivoclar Vivadent); group S, Vita Suprinity PC A3 (Germany); and group C, Cerasmart 270 A3 (Japan). Forty disks were milled from the four ceramic materials, with tendisks per group. Each disk was prepared to a thickness of 10 mm. All specimens were immersed in a mimicked gastric-like acidic solution (to resemble what takes place in the case of GERD). A spectrophotometer was used to detect the color difference ∆E, which represented the color shift before and after acid immersion. Translucency parameter (TP) numerical values were collected.
Results: The findings revealed a statistically significant difference (P < 0.05) among the groups. Group C (Cerasmart 270) exhibited the most important color change and the least color stability, followed by groups E (IPS e.max) and S (Vita Suprinity). In contrast, group Z (Ceramil Zolid) showed the least color change and the best color stability. After immersion in a gastric-like acidic solution, each ceramic material's translucency parameter (TP) exhibited a statistically significant difference (P ˂ 0.05). Only group C (Cerasmart 270) experienced a substantial loss in translucency, while groups Z (Ceramil Zolid), E (IPS e.max), and S (Vita Suprinity) experienced a significant increase in translucency.
Conclusion: A high-translucency zirconia material (Ceramil Zolid) in group Z, after being immersed in gastric-like acid, demonstrated the most color stability, while a hybrid ceramic CAD/CAM block (Cerasmart 270) in group C demonstrated the least. Both color change and translucency parameters were influenced by gastric-like acid immersion for all tested CAD/CAM ceramics.