To evaluate the clinical quality of ceramic (Optec) inlays, the inlay production of 10 dentists, se-ed by 3 dental laboratories, was examined independently by 2 calibrated examiners. A total of 57 patients with 205 inlays (mean age, 8.1 months) were examined 1 to 32 months after placement by means of using a slightly modified form of the California Dental Association criteria. Periodontal variables such as plaque index, gingival index, and margin index were also recorded. Eight patients reported postoperative but not persistent hypersensitivity in relation to the Optec therapy. No differences between Optec proximal surfaces and homologous control surfaces were seen with regard to plaque or bleeding on probing. The examination using the CDA criteria showed that 59% of the inlays had a slight color mismatch. Slightly roughened surfaces were most common (86%). As to anatomic form and margin integrity, 24% and 67%, respectively, of the inlays were rated excellent. A difference between the dentist with regard to the clinical quality of the inlay treatment procedure was seen. The present results cannot allow a definitive judgement with regard to the long-term clinical quality of the Optec inlay system but will serve as a base for further studies.