METHOD FOR DETERMINING ADHESION STRENGTH OF HARDENED DENTAL CEMENT TO A BASE AND A DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2019 - IPC A61C13/00 

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely to dentistry, and concerns a method for determining adhesion strength of hardened dental cement with a base and a device for determining adhesion strength of hardened dental cement with a base. Method involves preparation of equipment, preparation of dental cement solution, pouring cement solution, holding it in a thermostat, then testing hardened cement samples for breaking. When preparing accessories for testing, the tooth surface of the tooth model is treated with sand, creating a rough surface, and coating it with layers of lacquer, after varnish drying according to the tooth model, a wax composition of the crown model is made with a conical surface inside and a crown model with a ring in the upper part. Then, the dried wax film is washed with acetone and a dose of the freshly prepared cement solution is poured into the conical cavity of the cast crown, a conical part of the tooth model is inserted into the cone-shaped cavity of the tooth crown model until the model edges touch, and the entire equipment is placed with the dental cement filled into the thermostat. At the end of hardening of dental cement, a sample in the form of a truncated hollow cone with wall thickness equal to the thickness of a dried lacquer film is fixed with a tool in a breaking machine. Pressure is applied to tension, created pressure and breakaway pressure are recorded, and obtained adhesion strength of cemented dental cement is determined from the obtained data. Adhesion strength is determined by formula A = H / S, where H is pressure, at which there was a breakdown of the crown model from tooth model, S is area of contact surface of models. Proposed device comprises tooling to accommodate cement solution and to fix it in tensile machine. Tooling consists of upper and lower parts with possibility to lay dental cement solution between them. Lower part represents a model of crown with ring for attachment, inside there is cavity in form of truncated cone. Upper part represents a tooth model in the form of a truncated cone with a thickened base; at the bottom there is an opening with a thread for attachment.

EFFECT: high accuracy of quantitative evaluation of adhesion.

4 cl, 2 dwg, 1 tbl