The effect of two different treatment modalities on the tissue integration of Frialit implants was compared in an experimental study in 10 monkeys. The maxillary central incisors were extracted. In one extraction site, chosen by lot, a Frialit implant was immediately inserted, allowing the implant to penetrate the oral mucosa. In the contralateral extraction site, a modified Frialit implant was placed and allowed to heal under a mucoperiosteal flap. None of the implants used in the study was loaded during the observation periods. After experimental periods of 1, 3, 6, and 8 months, the implants were evaluated and monkeys were sacrificed. In situ and histological evaluation showed no significant difference between the two treatment modalities under nonloading conditions. In both cases the healing around the implants was uneventful and good tissue integration was achieved. Schlagwörter: ceramic implants, Frialit implants, histology, microradiography, monkey, oral surgery, osseointegration