Computerized occlusal analysis in patients with fixed dental restorations on implants

Abstract

The development of aesthetic and restorative dentistry and implantology leads to an increasing use of implants in the treatment of care for the loss of one or more teeth. The question is whether the existing guidelines, originally formulated for the occlusion of natural dentition and conventional prosthetic treatment can be applied to the implant prosthodontics. Due to initial differences in the vertical mobility of teeth and dental implants, present in the same dental arch, although the model of occlusion is ideal, undesirable premature occlusal contacts on the fixed dental restorations on implants may be present. Occlusal forces, in the dental arch partially reconstructed with fixed dental restorations on implants, must be planned so that the initial contacts in a position of maximum intercuspidation are on the natural teeth or fixed dental restorations on natural teeth. With the concept of delayed initial occlusal contacts on implants, you get balanced distribution of occlusal forces, physiological load of implants, preserve the integrity of peri-implant bone tissue, with favorable effects on prognosis and longlasting prosthetic treatment in implants. The main objective of the doctoral dissertation was to examine the intensity and time of establishing occlusal contacts of natural teeth and fixed dental restorations on implants with antagonists at different head postures, in a position of maximum intercuspidation. The research was conducted as a prospective clinical study in which research subjects were followed in period of one year. For the achievement of set goals and tasks, in this study two groups were included: control group included 17 patients of both sexes, with a full dental arches in the upper and lower jaw, and the experimental group that consisted of 14 patients with full dental arches in the upper and lower jaw, who in the past year had prosthetic treatment with fixed dental restorations on implants. In both groups of patients clinical functional analysis of occlusion and the conventional procedure of testing the occlusal equilibration was first performed. Then the condition of the occlusal complex of nature teeth and fixed dental restorations on implants was tested with the latest computerized T-Scan III method. Research results indicate that because of the initial difference in the vertical mobility of teeth and implants present in the same dental arch, premature occlusal contacts may be present on fixed dental restorations on implants. Quantitative occlusal analysis showed statistically significantly higher number of premature occlusal contacts in the experimental group of patients at all three positions of the head, of which approximately one early contact was localized on implant crowns. Relative occlusal forces were statistically significantly stronger on posterior compared to anterior teeth. The relative occlusal forces values on the front teeth in all three positions of the head, were higher in the experimental group subjects, while bilateral uniform distribution of occlusal forces around mediosagittal plane was registered in both groups. Longer time of establishing occlusal contacts was recorded in the experimental group subjects, but without statistical significance...

Razvoj estetske restaurativne stomatologije i implantologije, dovodi do sve veće primene implantata u terapiji zbrinjavanja gubitka jednog ili više zuba. Pitanje je da li se postojeće smernice, originalno formulisane za okluziju u prirodnoj denticiji i konvencionalnoj protetskoj terapiji, mogu primeniti i u implantat protetici. Zbog inicijalne razlike u vertikalnoj pokretljivosti zuba i implantata prisutnih u istom zubnom luku i pored idealnog modela okluzije, mogu biti prisutni neželjeni prevremeni kontakti na fiksnim zubnim nadoknadama na implantatima. Okluzalne sile se, u zubnom luku delimično rekonstruisanom fiksnim zubnim nadoknadama na implantatima, moraju ostvarivati tako da se inicijalni kontakti u maksimalnoj Ikp nalaze na prirodnim zubima ili fiksnim zubnim nadoknadama na prirodnim zubima. Konceptom odlaganja inicijalnog okluzalnog kontakta na implantatima, postiže se uravnotežena distribucija okluzalnih sila, fiziološko opterećenje implantata, očuvanje integriteta peri-implantatnog koštanog tkiva, sa povoljnim uticajem na prognozu i dugotrajnost protetske terapije na implantatima. Osnovni cilj doktorske disertacije bio je ispitati intenzitet i vreme uspostavljanja okluzalnih kontakata prirodnih zuba i fiksnih zubnih nadoknada na implantatima sa antagonistima pri različitim položajima glave, u toku maksimalne interkuspacije mandibule. Istraživanje je sprovedeno kao prospektivna klinička studija u kojoj su subjekti istraživanja praćeni u vremenskom periodu od godinu dana. Za ostvarivanje postavljenih ciljeva i zadataka, u istraživanje su bile uključene dve grupe pacijenata: Kontrolnu grupu činilo je 17 pacijenata, oba pola, sa punim zubnim nizom u gornjoj i donjoj vilici, dok je eksperimentalnu grupu činilo je 14 pacijenata sa punim zubnim nizom u gornjoj i donjoj vilici koji su u poslednjih godinu dana protetski zbrinuti fiksnim zubnim nadoknadama na implantatima. Ispitanicima obe grupe je prvo izvršena klinička funkcijska analiza okluzije i konvencionalni postupak provere okluzalnog uravnoteženja. Zatim je stanje okluzalnog kompleksa prirodnih zuba i fiksnih zubnih nadoknada na implantatima ispitivano najsavremenijom kompjuterskom T-Scan III metodom. Rezultati istraživanja ukazuju na to da zbog inicijalne razlike u vertikalnoj pokretljivosti zuba i implantata prisutnih u istom zubnom luku i pored idealnog modela okluzije, mogu biti prisutni neželjeni prevremeni kontakti na fiksnim zubnim nadoknadama na implantatima. Kvantitativnom analizom okluzije evidentiran je statistički značajno veći broj prevremenih okluzalnih kontakata u eksperimentalnoj grupi ispitanika pri sva tri položaja glave, od čega je prosečno jedan prevremeni kontakt bio lokalizovan na krunama na implantatima. Relativne sile u sva tri položaja glave, bile su statistički značajno jače na bočnim u odnosu na prednje zube. Vrednosti relativnih sila na prednjim zubima u sva ti položaja glave, bile su veće u eksperimentalnoj grupi ispitanika, dok je bilateralna ravnomerna distribucija okluzalnih sila oko mediosagitalne ravni registrovana u obe grupe ispitanika. Više vrednosti vremena uspostavljanja okluzalih kontakata zabeležene su u eksperimentalnoj grupi ispitanika, ali bez statističke značajnosti...