Justification of forming active prosthetic segments

Abstract

The aim of this paper was to examine the justification of forming active prosthetic segments on the abutment teeth for the incline of the elements of removable partial denture. Methods. The investigation was performed during 3-years observational period, at the Prosthodontic Clinics of Belgrade University Dental School, and the Military Medical Academy (MMA). During the mentioned observation period two groups of 200 patients with different kinds of edentulousness were analyzed, indicated for the design of metal frame removable partial dentures (MFRPD) with cast clasps. A total of 400 patients represented 50% of the sample chosen by random choice method for the determined observational period and dental institutions. Results. The evaluation of justification of the abutment teeth preparation was done during the analysis of the requirement of forming: guide planes, planes for occlusal rests, vestibular under cut, oral under cut. Conclusion. Upon the evaluation of the performed analyses the following can be concluded: during the composition of every MFRPD it is necessary to use at least two or more guide planes, depending on the type edentulousness of patients' teeth; formation of guide planes is performed in excessively high number of the abutment teeth (over 95%); during the composition of each particular MFRDP it is necessary to use as more occlusal rests as possible, at least 3, or more, which also depends on the type of patients' edentulousness; composition of the planes for occlusal rest has to be performed in almost all the patients (over 95% of the abutment teeth); vestibular planes of the abutment teeth should be prepared in over 50% of the used teeth; oral planes are prepared within the preparation of the abutment teeth for other active prosthetic segments. Conclusion. It is necessary to perform the composition of active prosthetic segments according to the plan established for the study models, both if the preparation of teeth for the adoption of MFRDP elements with clasps represents the use of an uninvasive, or an invasive dental method.

Cilj rada predstavlja ispitivanje opravdanosti formiranja aktivnih protetskih segmenata na retencionim zubima za prihvatanje elemenata parcijalnih skeletiranih proteza. Metode. Ispitivanje je obavljeno u okviru opservacionog perioda od tri godine na Klinikama za stomatološku protetiku Stomatološ kog fakulteta Univerziteta u Beogradu i Vojnomedicinske akademije( VMA). Analizirano je po dve stotine pacijenata različitih vrsta krezubosti, sa postavljenim indikacijama za izradu parcijalne skeletirane proteze (PSP) sa livenim kukicama. Svih četiri stotine pacijenata predstavljaju 50% uzorak odabran metodom slučajnog izbora za dati opservacioniu period i stomatološke ustanove. Rezultati. Procena opravdanosti pripreme retencionih zuba, izvršena je u okviru analiziranja potrebe formiranja: vodećih površina, ležišta za okluzalne naslone, vestibularne podminiranosti i oralne podminiranosti. Prilikom izrade svake PSP neophodno je korišćenje najmanje dve ili više vodećih površina. Formiranje vodećih površina vrši se kod izuzetno velikog broja retencionih zuba (preko 95%). Pri izradi PSP neophodno je korišćenje što većeg broja okluzalnih naslona, (najmanje tri i više), što svakako takođe zavisi od vrste krezubosti pacijenta. Formiranje ležišta za okluzalne naslone mora se izvesti kod skoro svih pacijenata (preko 95% retencionih zuba), a vestibularne površine retencionih zuba trebalo bi pripremiti kod preko 50% korišćenih zuba. Oralne površine se pripremaju u okviru pripreme retencionih zuba za ostale aktivne protetske segmente. Zaključak. Bez obzira da li priprema zuba za prihvatanje elemenata PSP sa livenim kukicama predstavlja korišćenje jedne od neinvazivnih ili invazivnih stomatoloških metoda, obavezno je izvršiti formiranje aktivnih protetskih segmenata i to prema planu postavljenom na modelu za studije.