Assessment of telescopic denture's settling in phase duration

Abstract

Introduction. Double telescopic crowns are connecting elements of partial dentures and are considered to be prosthetic devices of high aesthetic and biological value. Their basic drawback is the assessment of retention force value which has to be strong enough to balance the opposite forces but, nevertheless, must not result in harming the periodontal tissue of retention teeth while taking the denture off. The retention force is the highest immediately after the denture's construction and is progressively declining until the end of the 'settling in phase', i.e. until the retention force value becomes well-established. Aim of the study was the measurement of the overall retention force of completed telescopic dentures and a survey of 'settling in phase' duration. Methods. The measuring was conducted on 20 telescopic dentures consisting of 2, 3 or 4 telescopic crowns made of gold alloy type IV and executed by dynamometer. Results. An optimal retention force was detected in only 37% of telescopic dentures. An insufficient retention force was observed in 16%, while in the remaining 47% an excessive force was detected. In the largest number of dentures (35%) the settling in phase began after 33 cycles, which shows that this phase takes on average 10,6 days. Conclusion. The 'settling in phase', during which retention force becomes stabilized, is completed in the first ten days after the delivery of the completed telescopic denture.

Uvod. Dvostruke teleskop krune predstavljaju vezne elemente parcijalne proteze i smatraju se zubnim nadoknadama visokih estetskih i bioloških vrednosti. Njihov osnovni nedostatak predstavlja procena veličine retencione sile, koja mora biti dovoljno velika da uravnotežava suprotne sile a da sa druge strane, prilikom skidanja, ne dovodi do oštećenja parodontalnog tkiva zuba nosača. Retenciona sila je najveća odmah po izradi proteze i ona progresivno opada sve dok se ne završi tzv. 'faza uhodavanja', odnosno dok vrednost retencione sile ne postane ustaljena vrednost. Cilj istraživanja bio je merenje ukupne retencione sile gotovih teleskop proteza i ispitivanje vremenskog trajanja 'faze uhodavanja'. Materijal i metod. Merenja si vršena na 20 teleskop proteza, koje su u svom sastavu imale 2, 3 ili 4 teleskop krune izrađene od legure zlata tip IV. Merenja su vršena pomoću dinamometra. Rezultati. Kod samo 37% teleskop proteza registrovana je optimalna retenciona sila. Kod 16% registrovana je nedovoljna retenciona sila, dok je kod ostalih 47% registrovana prekomerna retenciona sila. Kod najvećeg broja proteza (35%), faza uhodavanja nastupila je nakon 33 ciklusa, što znači da je potrebno u proseku 10,6 dana za 'fazu uhodavanja'. Zaključak. 'Faza uhodavanja' tokom koje dolazi do ustaljenja retencione sile u proseku se završava u okviru prvih deset dana nakon predaje završene teleskop proteze.