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Various bone cements with different compositions were prepared in several model configurations which differed in volume (i.e. setting temperature profile) and mode of mixing (manual and vacuum bowl). Local mechanical properties (nanohardness, elasticity modulus) of all experimental states were measured by nanoindentation technique and compared. Role of the preparation route as well as influence of composition, particularly of presence of antibiotics, on the measured properties was investigated.

Članak obuhvaća studiju uporabe ultrazvučnog pulzirajućeg mlaza vode odabranih svojstava za razgradnju veze ostvarene pomoću koštanog cementa između cementiranog bedrenog drška i trabekularnog koštanog tkiva, kao potencijalne tehnike za revizijsku artroplastiku. Šest tipova komercijalnog koštanog cementa baziranog na polimetil metakrilatu rabljeni su za ovo istraživanje. Cementi su miješani uz pomoć DePuy - SmartMix® CTS / vakumske zdjele za miješanje. Mehanička svojstva ojačanog koštanog cementa određena su nanoindentacijom. Uzorci koštanog cementa su razgrađeni primjenom tehnologije pulzirajućeg mlaza vode. Tlak vode se mijenjao između 8 i 20 MPa. Kružna mlaznica s promjerom otvora od 0,7 mm je rabljena za rezanje mlazom vode. Odstojanje od ciljanog materijala bilo je 2 mm, a poprečna brzina iznosila je 1 mm/s. Volumen odstranjenog materijala i dubina kreiranih tragova mjereni su pomoću MicroProf FRT optičkog profilometra. Rezultati pozitivno podupiru pretpostavku da pulzirajući mlaz vode ima potencijal biti odgovarajuća tehnika za brzu i sigurnu razgradnju koštanog cementa pri revizijskoj artroplastici., The paper deals with the study of using the selective property of ultrasonic pulsating water jet for the disintegration of the interface created by bone cement between cemented femoral stem and trabecular bone tissue as a potential technique for revision arthroplasty. Six types of commercial bone cements based on Polymethyl Methacrylate were used for investigation. The cements were mixed using the DePuy - SmartMix® CTS / vacuum mixing bowl. Mechanical properties of hardened bone cements were determined by nanoindentation. The bone cement samples were disintegrated using the pulsating water jet technology. The water pressure varied between 8÷20 MPa. A circular nozzle with an orifice diameter of 0,7 mm was used for water jetting. The stand-off distance from the target material was 2 mm and the traverse speed 1 mm/s. The volume of material removal and depth of created traces were measured by MicroProf FRT optical profilometer. The results positively support an assumption that pulsating water jet has a potential to be a suitable technique for the quick and safe disintegration of bone cement during revision arthroplasty.

Improving of bone cements properties is possible by research of variables influencing exothermal behaviour and mechanical properties. Paper deals with exothermal behaviour experimental evaluation of bone cements used for medical purposes. Specimens were prepared by a conventional manual mixing technique. The work addresses primary risk factor associated with application of bone cement to femoral canal. Different size samples of bone cement has been created with diameter d = 2; 5;12,5 mm fixed in dentacryl. As an experimental material, Palacos R+G high viscosity, radiopaque bone cement containing Gentamicin and Radiopaque bone cement Antibiotic Simplex with Tobramycin, was used. Thermal effect during exothermic polymerisation was measured with period 1 minute. Evaluated factors were mass and thickness of bone cement. Significant influence of bone cement mass on temperature has been found.