Immediate implant loading with fixed dental restorations: An animal model study

Abstract

Background/Aim. Immediate loading is considered to be the most innovative technique in contemporary implant dentistry. Recent clinical and experimental findings have demonstrated that only implants with high primary stability can be subjected to immediate loading protocol with predictable results. It is generally accepted that the most important prerequsite for successful osseointegration is achievement and maintenance of implant stability. The aim of this in vivo study was to investigate the possibility for successful application of immediate loading protocol in implant systems with different surface properties. Methods. In the experimental study 2 mongrel dogs were edentulated bilaterally in the mandibular and maxillary premolar areas. After 3 months implants were placed in a pattern 4 different commercially available implants per quadrant (n = 32): Mk III TiUnite (Nobel Biocare, Sweden), ITI TPS (Straumann, Switzerland), 3IOsseotite (Implant Innovation, USA) and XiVE Cell-Plus (Friadent, Germany). Implants were subjected to immediate loading with 4 unit gold cast bridges, 2 days post implantation. The assessment of implant stability and immediate loading possibilities were done by performing Resonance frequency analysis (RFA). Results. After a 6- month loading period all bridges were in function and all implants occurred well osseointegrated. When summarizing the Implant Stability Quotient (ISQ) values, it was noted that resonance frequency was significantly higher for mandibular implants. The results of this experimental setting showed that all evaluated surfaces achieved good implant stability. Increase of ISQ values was found for all implants in the mandible and partially decrease of ISQ values for maxillary implants after 6 months of functional loading with 4 unit bridges. Conclusions. Investigated endooseal implants did not show different degree of osseointegration, because there was not statisticaly significant difference among observed parameters (ISQh i ISQp) between implant systems.Uvod/Cilj. Imedijatno opterecenje implantata smatra se jednim od najznacajnijih dostignuca savremene dentalne implantologije. Rezultati novijih klinickih i eksperimentalnih studija pokazali su da samo implantati visoke primarne stabilnosti mogu biti izlozeni protokolu imedijatnog opterecenja zubnom nadoknadom sa predvidivim ishodom. Cilj studije bio je da se ispita mogucnost uspesne primene protokola imedijatnog opterecenja implantata razlicitog mikrodizajna fiksnim zubnim nadoknadama. Metode. U eksperimentalno istrazivanje ukljucena su dva psa, obezubljena obostrano u premolarnoj regiji gornje i donje vilice. Nakon tri meseca od ekstrakcije zuba, ugradjena su, po predvidjenoj semi, cetiri razlicita implantata po kvadrantu (n = 32): Mk III TiUnite (Nobel Biocare, Sweden), ITI TPS (Straumann, Switzerland), 3I-Osseotite (Implant Innovation, USA) i XiVE Cell-Plus (Friadent, Germany). Implantati su imedijatno optereceni fiksnim zubnim nadoknadama, cetvoroclanim mostovima od plemenite legure zlato-platina, dva dana posle implantacije. Stabilnost implantata i mogucnost imedijatnog opterecenja ocenjivana je na osnovu analize rezonantnih frekvencija (RFA). Rezultati. Sest meseci nakon implantacije i imedijatnog opterecenja fiksnom zubnom nadoknadom, svi mostovi bili su u funkciji i svi implantati uspesno integrisani, ne pokazujuci znake mobilnosti. Sumiranjem dobijenih vrednosti koeficijenta stabilnosti implantata (ISQ) ustanovljeno je da su rezonantne frekvencije bile znacajno vece kod implantata u donjoj vilici. Rezultati eksperimentalnog istrazivanja pokazali su da su sve analizirane povrsine ostvarile dobru implantatnu stabilnost. Utvrdjen je porast ISQ vrednosti kod svih implantata u mandibuli i delimican pad ISQ vrednosti za implantate u maksili, nakon sest meseci funkcionalnog opterecenja fiksnim zubnim nadoknadama. Zakljucak. Ispitivani endoosealni implantati nisu pokazali razlicit stepen oseointegracije jer se rezultati merenih parametara hirurskih (ISQh) i protetkih (ISQp), nisu statisticki znacajno razlikovali izmedju implantatnih sistema.