In vitro evaluation of the influence of bone cortical thickness on the primary stability of conventional- and short-sized implants

Abstract

Background The aim of this in vitro study was to evaluate the influence of the cortical thickness on the primary stability of short and conventional-sized implants with two types of prosthetic connection. Material and Methods Seventy-two implants were used. These implants were placed in polyurethane blocks that simulated low-density bone tissue (type IV bone), with two bone cortical heights (type I bone): 1mm and 3mm. The implants were divided into 6 groups with 12 implants each according to the type of prosthetic connections (external-hexagon -EH and morse taper- MT) and implant sizes (conventional- 4x10mm and short 5x5mm; 5.5x5mm; 5x6mm; 5.5x6mm). Insertion torque (IT) and resonance frequency analyzes (RFA) were performed to evaluate the primary stability of the implants. Results All implants installed in blocks with 3mm of cortical thickness showed greater IT than those installed in 1mm. The short-sized MT implants had a higher IT than conventional implants of the same connection. Short-sized EH implants showed less IT than short-sized MT implants in blocks with 3mm of cortical. In blocks with 1mm of cortical, conventional EH implants had a higher IT compared to short-sized EH implants. The conventional sized implants presented higher RFA values despite the thickness of the cortical in the blocks. Conclusions The greater bone cortical thickness and implants size provides greater primary stability of the implants regardless the prosthetic connection. Key words: Implants connection, implants macrostructure, primary stability.

Insertion and removal torque of dental implants placed using different drilling protocols: An experimental study on artificial bone substitutes

“…Chávarri‐Prado evidenced that implants placed in polyurethane blocks with cortex registered higher values on IT compared to implants placed in blocks without cortex 24 . Similar findings were reported by Barros using artificial bone blocks, where primary stability was weakly determined by implant length or connection, but strongly related to the thickness of the cortex 25 …”

“…24 Similar findings were reported by Barros using artificial bone blocks, where primary stability was weakly determined by implant length or connection, but strongly related to the thickness of the cortex. 25 This in vitro study has some limitations. While controlled characteristics of the bone constructs (homogeneity of the block with no organic components), drilling technique, and drill types allowed for an experimental model that was standardized, this does not fully represent the behavior of implant drills in natural bone and as used in clinical settings.…”

Effect of different thread configurations on hydrophilic implant stability. A split-mouth RCT

“…In addition, long-term assessments to determine whether these different macrostructures significantly affect implant success and survival are also needed. Finally, the lengths of the implants used were different (CTH - 10 mm vs. CTP - 9 mm), but this characteristic does not seem to significantly affect the stability of the implants compared with the implant’s diameter 6 .…”

“…One controllable factor linked to success in osseointegration is the achievement of good primary stability, which makes secondary stability a more predictable event (2,3). Structural modifications in dental implants have been proposed to optimize the osseointegration process, and these modifications can be performed in the macrostructure or microstructure of the implants (3)(4)(5)(6)(7). Changes in the macrostructure more directly affect primary stability and the decision to establish immediate load application (3,6,8), while microstructural modifications are related to the acceleration of the conversion from primary to secondary stability due to biological stimuli in the osseointegration process (5,(9)(10)(11).…”

Comparação da expansão óssea promovida pela técnica de osseodensificação com dois tipos de conjunto de fresas

“…A estabilidade do implante está diretamente relacionada à qualidade do osso em contato com o implante, e essa densidade óssea tem sido relatada como o principal fator para obtenção da estabilidade 16,17 . Neste estudo, o método de utilização de fresas expansivas resultou em um aumento significativo da densidade óssea nas perfurações, lateralmente e apicalmente.…”