Effect of surgical technique and implant micro and macro design on stability of implants placed in posterior maxilla

Abstract

Sufficient primary implant stability is very important factor that affects long-term implant success and depends on diameter and length of the implant, shape of implant body, features of implant threads (macro design), surgical technique used as well as on the quality and quantity of the available jaw bone. Primary stability is hard to achieve in posterior maxilla due to low density of bone in this region. Since the quality and quantity of the jaw bone are factors that are already present, the effect of surgical techniques, implant's macro and micro designs on improvement of implant stability in low-density bone were assessed in this doctoral dissertation. The aim was to investigate and compare implant stability between self-tapping and non self-tapping implants inserted in low-density bone following lateral bone condensing or standard surgical techniques. Also, to investigate and compare implant stability between implants with hydrophobic and hydrophilic surfaces inserted into the low-density bone. Experimental and clinical study were performed. In the „in vitro“ study, pig ribs with uniform thickness of corticalis of 2 mm were used to simulate jaw bone type D3 or D4 according to Carl and Misch classification. With regards to surgical technique (lateral bone condensing or standard surgical technique) and implant macro design (self-tapping and non self-tapping), bone samples were randomly divided into 4 test groups to allow investigation of all possible combinations of the tested factors. Implant stability was measured in thermostat controlled water bath using Resonance Frequency Analysis (RFA) as a method of measurement. A total of 46 patients (26 females and 20 males) with a mean age of 39.3 years were included in the clinical study and they received a total of 144 implants in the following way: 48 self-tapping implants (24 following lateral bone condensation and 24 following standard surgical technique), 48 non self-tapping implants (24 following lateral bone condensation and 24 following standard surgical technique), 24 implants with hydrophilic surface and 24 implants with hydrophobic surface following standard surgical technique...

Odgovarajuća primarna stabilnost implantata je osovni faktor koji utiče na dugotrajan uspeh endoosealnih implantata, što zavisi od dijametra i dužine implantata, oblika tela implantata, karakteristika navoja implantata (makro dizajn), primenjene hirurške tehnike, kao i od kvaliteta i količine raspoložive kosti. Primarnu stabilnost implantata je teško postići u bočnim segmentima gornje vilice zbog male gustine kosti u ovoj regiji. Kako su kvalitet i količina kosti faktori koji su već prisutni, u ovoj doktorskoj disertaciji ispitivan je uticaj različitih hirurških tehnika, makro i mikro dizajna implantata na poboljšanje stabilnosti implantata u kosti male gustine. Cilj doktorske disertacije je bio ispitati i uporediti vrednosti implantne stabilnosti između implantata sa samourezujućim i neurezujućim navojima ugrađenih nakon preparacije ležišta metodom lateralne kondenzacije i standardnom tehnikom u kost male gustine. Takođe, ispitati i uporediti vrednosti implantne stabilnosti između implantata sa hidrofobnom i implantata sa hidrofilnom površinom ugrađenih u kost male gustine. Preduzeta su eksperimentalna i klinička istraživanja. U sprovedenoj „in vitro“ studiji korišćena su svinjska rebra uniforme debljine koritkalnog sloja od 2 mm radi simulacije klase D3 i D4 po Carl-u i Misch-u humane vilične kosti. Prema hirurškoj tehnici za peparaciju ležišta implantata (lateralna kondenzacija kosti i standardna tehnika) i makro dizajnu implantata (samourezujući i neurezujući), uzorci kosti su metodom slučajnog izbora bili podeljeni u 4 grupe čime je bilo omogućeno ispitivanje svih kombinacija testiranih faktora. Merenje implantatne stabilnosti vršeno je u termostatom kontrolisanom vodenom kupatilu metodom analize rezonantne frekvencije (engl. Resonance Frequency Analysis RFA). U kliničku studiju je bilo uključeno ukupno 46 pacijenata (26 ženskog i 20 muškog pola) prosečne starosti 39.3 godina i kod njih je ugrađeno ukupno 144 implantata i to: 48 samourezujućih implantata (24 u ležišta preparirana lateralnom kondenzacijom kosti i 24 u ležišta preparirana standardnom tehnikom), 48 neurezujućih implantata (24 u ležišta preparirana lateralnom kondenzacijom kosti i 24 u ležišta preparirana standardnom tehnikom), 24 implantata hidrofilne i 24 implantata hidrofobne površine u ležišta preparirana standardnom tehnikom...