Admira

This in vitro study was conducted between June 2019 and July 2020, in the Dental Materials Department at the University of Medicine and Pharmacy “Iuliu Hațieganu” in Cluj-Napoca. The study was approved by the university’s ethics committee (approval number 805.13.05.26). The teeth were collected from the surgery department of our university. Human lower incisors that had been removed for orthodontic or periodontal reasons were chosen. The teeth were healthy and had no caries lesions. Using a dual-axis chewing simulator (CS-4.2, SD Mechatronik, Feldkirchen-Westerham, Germany; Figure 1) to replicate normal masticatory conditions and bruxism conditions, teeth were tested for two different materials: a flowable composite, Gradia direct flo^® (GC, Tokyo, Japan) and an ormocer, Admira^® (VOCO, Cuxhaven, Germany). A total of eighty teeth were enrolled. Four groups were formed, each containing twenty teeth: the first group was the composite group, under mastication conditions, (1; Gradia—mastication conditions), the second group was the ormocer group under mastication conditions (2; Admira—mastication conditions); the third group was the composite group under bruxism conditions (3; Gradia—bruxism conditions) and the fourth group was the ormocer group under bruxism conditions (4; Admira—bruxism conditions).

In this study, four dental resin composites were used: a low-shrink, low-stress composite (Kalore^TM, GC Corporation, Tokyo, Japan), an ormocer-based composite (Admira^®, Voco, Cuxhaven, Germany), a bulk-fill composite (Tetric^® N-Ceram Bulk Fill, Ivoclar-Vivadent, Schaan, Liechtenstein), and a nanofilled composite (Filtek^TM Z350 XT, 3M ESPE, St. Paul, MN, USA). Information on their manufacture is listed in Table 1.