Avtor/Urednik		Jamšek, Jure; Kopač, Igor
Naslov		Razsežnostne spremembe mavčnih modelov, ulitih v različnih presledkih iz enega silikonskega odtisa
Prevedeni naslov		Dimensional changes of plaster models produced from one silicone impression following multiple pour at different time intervals
Tip		članek
Vir		Zobozdrav Vestn
Vol. in št.		Letnik 61, št. 4-5
Leto izdaje		2006
Obseg		str. 141-8
Jezik		slo
Abstrakt		Background: Production of three plaster models from one elastomeric impression is a laboratory procedure used with the purpose of producing more accurate restorations. The aim of our study was to establish whether dimensional stability of modern silicone impression materials allows a repeat pour of three plaster models that are comparable to one another in terms of accuracy. Materials and methods: A stainless steel model was fabricated in the shape of a plate with three different cylinders fixed perpendicularly to it at the angle points of an imaginary equilateral triangle. Impressions of the steel model were taken using four addition silicones and one condensation silicone. Each impression was used for the production of three plaster models: the first one was poured four hours after impression taking, the second one a day after, and the third one a week after. The diameters and heights of the cylinders as well as the distances between them were measured with a digital beak-shaped gauge. Results: The greatest shrinkage of cylinder diameters (0.31-0.52%) was measured on models that were poured a week after impression taking with addition silicones. When the condensation silicone was used, cylinder diameters expanded. Cylinder heights also showed the greatest increase in the models poured a week after impression taking (0.38-1.11%). The changes in distances between the cylinders ranged from -0.15% to +0.16%. Conclusions: One elastomeric impression allows the production of three plaster models that fulfil clinical and laboratory requirements. The accuracy of models from the first two pours is comparable; the third model poured a week after impression taking shows slightly bigger dimensional changes.
Izvleček		Izhodišče: Izdelava treh mavčnih modelov iz enega elastomernega odtisa se v laboratorijski fiksni protetiki vse pogosteje uveljavlja z namenom doseči večjo natančnost fiksnoprotetičnih izdelkov. V raziskavi nas je zanimalo, ali so sodobni silikoni dovolj dimenzijsko obstojni, da dovoljujejo ulivanje treh mavčnih modelov, ki so med seboj primerljivo natančni. Materiali in metode: Izdelali smo osnovni model iz nerjavnega jekla v obliki plošče, na kateri so bili pritrjeni trije različni valji, razporejeni v enakostranični trikotnik. Osnovni model smo 3-krat odtisnili s štirimi adicijskimi in enim kondenzacijskim silikonom. Nato smo iz vsakega odtisa 4 ure, 24 ur in 1 teden po odtiskovanju ulili mavčni model. Na vseh modelih smo z digitalnim kljunastim merilom merili premer in višino valjev ter razdalje med njimi. Rezultati: Največje zmanjšanje premera valjev (0,31-0,52%) je bilo na modelih, ulitih en teden po odtiskovanju z adicijskimi silikoni. Pri kondenzacijskem silikonu se je premer valjev povečal. Višina valjev se je pri vseh silikonih najbolj povečala pri modelih, izdelanih en teden po odtiskovanju (0,38-1,11%). Spremembe razdalj med valji, ki kažejo na prostorske dimenzije celotnega odtisa po zamreženju, so znašale od -0,15 do +0,16%. Zaključek: En elastomerni odtis dopušča izdelavo treh mavčnih modelov, ki izpolnjujejo klinične in laboratorijske zahteve. Pri tem sta prvi in drugi primerljivo podobno natančna, medtem ko ima tretji model, izdelan 1 teden po odtiskovanju, nekoliko večje razsežnostne spremembe.
Deskriptorji		DENTAL MODELS DENTAL IMPRESSION MATERIALS DENTAL IMPRESSION TECHNIQUE SILICONE ELASTOMERS