The concept of replacing a tooth root is not a new one. The findings at archaeological excavations of old civilisations show that it has been a few centuries old. Ancient Egyptian and Mayan excavations discover a sort of primitive implants. Although it has been proved that most of those implants were inserted post-mortem as some sort of decoration, some of them have been proved to be in function. The development of modern dental medicine in 20th century caused the development of various techniques of implantation therapy and implant designs. Firstly, subperiosteal, transosteal and foliar implants were developed, but none of them were widely used due to numerous complications, their complexity and high costs. The introduction of endoseal dental implants as a possible prosthetic rehabilitation for partly or completely toothless patients showed a high percentage of success and is the choice method of oral rehabilitation. Implant therapy can not be applied always and in any situation and it also has some defects. We should be aware of a number of contraindications and possible complications. The most common complication of implant therapy is peri-implant pathology, which, thus, led to the development of various methods of treatment therapeutic procedures. Peri-implant pathology includes peri-implant mucositis and peri-implantitis. Peri-implant mucositis is a reversible inflammation of the peri-implant mucosa without any signs of the loss of the supporting bone, while peri-implantitis is caused by the progression of peri-implant mucositis and it is described as an inflammatory process of functional peri-implant tissue with the loss of the supporting bone. Knowing the microbiological etiology of the pathological processes, the aim of the therapy is to suppress pathogens connected with the infection and to make physiological microflora which is compatible with the healthy tissue. The therapeutic procedure depends on the stage of the peri-implant disease. The degree of the disease progression is tested by a few clinical parameters (PPD, BOP, plaque presence and purulent matter as well as the bone loss). Based on these, the protocol of therapeutic procedures is designed in order to treat peri-implant diseases. It is called cumulative interceptive supporting therapy (CIST protocol). The protocol consists of four steps, where each subsequent step completes the previous one. The protocol includes mechanical cleaning, antiseptic therapy and regenerative and resection therapy. There are various methods of mechanical cleaning and antiseptic therapy, while laser is also widely used in treatment of peri-implant pathology. Antibiotic therapy on its own is not enough for the treatment. We try to achieve the regeneration of extensive bone destruction with the use of membranes and bone transplant. It is possible to prevent peri-implant diseases with regular checkups and adequate oral hygiene. Thus, it is necessary to educate patients about the adequate hygiene and the importance of regular checkups in order to preserve general health and durability of implant therapy.