Dimensional Stability of Elastomeric Impression Materials Disinfected in a Solution of 0.5% Chlorhexidine Gluconate and Alcohol

Dezinfekcija elastomernih materijala za otiske može prouzročiti njihove dimenzijske promjene. Na našoj se klinici kao dezinficijens najčešće upotrebljava 0,5% klorheksidin glukonat. Svrha rada bila je izmjeriti i usporediti linearne dimenzijske promjene koje nastaju u trima elastomerima nakon uranjanja u spomenuti dezinficijens. Radni kalup napravljen je prema ADA specifikaciji br.19. Testirani su Panasil (adicijski silikon), Blend-a-scon (kondenzacijski silikon) i Impregum (polieter). Uzorci su izloženi dezinficijensu, vodi i zraku u četiri razdoblja (10 min., 30 min., 60 min. i tijekom 24 sata). Linearne dimenzijske promjene izmjerene su bezkontaktnim digitalnim alatnim mikroskopom. Rezultati su pokazali najmanje dimenzijske promjene adicijskog silikona s tendencijom širenja. Kondenzacijski silikon skvrčio se unutar tolerantnoga raspona od 0,2 - 0,4%, prema DIN 13913, a polieter je znatno nabubrio. Može se zaključiti da testirani polieter nije prikladno dezinficirati uranjanjem u klorheksidin glukonat, a druga dva materijala pokazuju klinički prihvatljive linearne dimenzijske promjene unutar 24-satne imerzije.Disinfection of elastomeric impression materials used in prosthetic dentistry can cause dimensional changes in the impression materials. 0.5% chlorhexidine gluconate is usually used for disinfection of impressions at the School of Dental Medicine in Zagreb. The purpose of this study was to measure and compare linear dimensional changes of three elastomeric impression materials after their immersion in a certain disinfectant. The master dies were made according to the ADA specification no 19. The tested materials were Panasil (addition silicone), Blend-a-scon (condensation silicone) and Impregum F (polyether). Twelve samples were immersed in disinfectant, twelve in water and twelve left in the air for four different periods of time (10 min., 30 min., 60 min and 24 hours). Linear dimensional changes were measured by a non-contact digital tool microscope. The smallest changes were noticed in addition silicone with the least tendency to expansion. The condensation silicone contracted within a tolerant range of 0.2 - 0.4%, according to DIN 13913. Polyether expanded in the disinfectant significantly. Our results show that the tested polyether is not appropriate for disinfection by immersion in chlorhexidine gluconate, while the other two materials underwent 24-hour immersion with linear dimensional changes within a clinically acceptable range