The aim of the study was to elucidate of changes in the level of lipid peroxidation products in saliva for the development of a method for the early diagnosis of complications in dental implantation. The study included 53 patients with complications of implant treatment, 31 patients with a safe outcome of dental implantation, and 13 clinically healthy individuals. In the saliva obtained at the stage of preparation for dental implantation, the content of products of lipid peroxidation was determined. Re-saliva was taken four months after dental implantation or in the case of peri-implantitis verification. It is established that the development of inflammatory complications of dental implantation is accompanied by the development of oxidative stress, which leads to local accumulation of lipoperoxidation products. An increase in the salivary level of products of lipid peroxidation during dental implantation is observed before the formation of clinically significant changes in the tissues of the implantation canal and is associated with a high risk of development of inflammatory complications of dental implantation. The most informative and prognostically unfavorable is the increase in the salivar level of the Schiff bases.