AIM: The surface gloss of restorative materials can be greatly impacted by abrasion from tooth brushing. This study aimed to evaluate the effect of simulated tooth brushing using regular and abrasive toothpaste on the surface gloss of glazed monolithic all-ceramic restorations. MATERIALS AND METHODS: In this, in vitro study, four different monolithic all-ceramic materials were used: Cerec Tessera (advanced lithium disilicate), Celtra Due (zirconia reinforced lithium silicate), Cerec Zirconia+ (Translucent Zirconia), and Cerec Blocs (Feldspathic). Eighty rectangular shaped specimens were made (20 of each material) using a low-speed diamond disc with the following dimensions (12/10/ 1 mm). The samples were polished using polishing kit & paste (DIAPOL, EVE). A glaze (Universal overglaze, Dentsply Sirona) was applied to all the samples then a toothbrushing simulator was used for 10.000 cycles using two different toothpastes. Surface gloss was assessed before and after simulated tooth brushing using glossmeter. RESULTS: The results showed a significant reduction in the mean surface gloss of the four materials after the use of regular and abrasive toothpastes (P <
0.001). In all materials, the use of abrasive toothpaste was associated with more reduction of surface gloss (P <
0.001). CONCLUSION: Simulated tooth brushing and toothpaste type affect the surface gloss of glazed monolithic all-ceramic materials. CLINICAL SIGNIFICANCE: The surface characteristics of monolithic all-ceramic materials is affected by abrasion from toothbrushing which could impact the surface of the materials and possibly alter the glaze coating, compromising the restoration's longevity and esthetics. This effect was greater with the use of abrasive toothpaste.