FIELD : medicine.SUBSTANCE : group of inventions includes fragmentary cofferdam for shielding of the teeth being treated and its use, relates to the field of medicine, in particular dentistry, and is designed to prevent the flow of fluids, such as saliva or blood, to the tooth being treated. Fragmentary cofferdam for shielding teeth to be treated comprises a tensioning cloth made of an elastic material and two control elements arranged on opposing ends of the tensioning cloth. Tensioning cloth is designed to be introduced into at least one intermediate tooth space from the occlusal side in a first tensioned state, which can be achieved by pulling apart the control elements in a tensioning direction, and to sealingly rest against the interdental gingiva and the approximal surfaces of the teeth forming the at least one intermediate tooth space in a second state after being introduced into the at least one intermediate tooth space. Each control element rests against at least one tooth and/or against the surrounding gingiva in the second state, and at least one strap is provided between the two control elements, extending in the plane of at least one web and is configured for insertion into the intermediate tooth space adjacent with intermediate tooth space meant for the introduction of at least one web.EFFECT : inventions widen the range of tools for the specified purpose.14 cl, 6 dwg