Impact of multi-step vs one-step finishing and polishing techniques on color stability of omnichroma composite restorations: In vitro spectrophotometric analysis

Background: This in vitro study aimed to analyze, using a spectrophotometer, the outcomes of two finishing and po- lishing techniques for composite restorations and to evaluate their color stability after exposure to a staining agent. Materials and Methods: Standardized class V cavities were prepared on sixty extracted intact molars and restored with Omnichroma composite (Omnichroma, Tokuyama Dental Corporation Inc., Tokyo, Japan) . The samples were divided into two groups: Group 1, finished and polished with the multi-step Astropol technique (Ivoclar Vivadent, Liechtenstein), and Group 2, finished and polished with the one-step Enhance technique (Dentsply Sirona, USA). Color changes were evaluated using a spectrophotometer immediately after polishing with each technique (T1) and after two weeks of immersion in a staining agent (T2). Color differences (ΔE) were calculated for intergroup and intragroup analyses. Results: No statistically significant differences were detected immediately after polishing (T1, p=0.059); however, significant variations emerged after immersion in the staining agent (T2, p<0.001). Conclusions: Intragroup analysis showed significant ΔE changes for the Enhance group (p<0.001) but not for the Astropol group (p=0.724). Both groups, however, exhibited ΔE > 2, indicating a perceptible color difference be- tween the restoration and sound dental tissue.