The present investigation reports an animal experiment the objective of which was to study the vascular topography of the periodontium and the peri-implant soft and hard tissues in the beagle dog. 2 beagle dogs were used. The right mandibular premolars were extracted and healing allowed for 3 months. 2 titanium fixtures a.m. Brånemark were installed in the right premolar region. Abutment connection was performed 3 months later. The contra-lateral mandibular sites were used as tooth harboring control units. A 4-month period of meticulous plaque control was initiated. A clinical and radiographical examination was performed towards the end of this period and revealed that the gingiva and peri-implant mucosa were clinically healthy and that the bone tissue at teeth and implants had a normal height. The carotid arteries were perfused with a mixture of carbon and calf serum. 2 bucco-lingual sections, about 100-150 microns thick, and one mesio-distal section comprising the junctional epithelium and underlying connective tissue were sampled. The sections were treated, cleared and examined in a microscope. The results of the present investigation demonstrated that the vasculature of the gingiva and the supracrestal connective tissue at teeth is derived from two sources, namely the supraperiosteal vessels lateral of the alveolar process and the vessels of the periodontal ligament. The blood vessels of the peri-implant mucosa were found to be terminal branches of larger vessels originating from the periosteum of the bone of the implant site.(ABSTRACT TRUNCATED AT 250 WORDS)