Impact of Different Titanium Implant Thread Designs on Bone Healing: A Biomechanical and Histometric Study with an Animal Model

Abstract

Threads of dental implants with healing chamber configurations have become a target to improve osseointegration. This biomechanical and histometric study aimed to evaluate the influence of implant healing chamber configurations on the torque removal value (RTv), percentage of bone-to-implant contact (BIC%), bone fraction occupancy inside the thread area (BAFO%), and bone and osteocyte density (Ost) in the rabbit tibia after two months of healing. Titanium implants with three different thread configurations were evaluated: Group 1 (G1), with a conventional “v” thread-shaped implant design; Group 2 (G2), with square threads; and Group 3 (G3), the experimental group with longer threads (healing chamber). Ten rabbits (4.5 ± 0.5 kg) received three implants in each tibia (one per group), distributed in a randomized manner. After a period of two months, the tibia blocks (implants and the surrounding tissue) were removed and processed for ground sectioning to evaluate BIC%, BAFO%, and osteocyte density. The ANOVA one-way statistical test was used followed by the Bonferoni’s multiple comparison test to determine individual difference among groups, considering a statistical difference when p < 0.05. Histometric evaluation showed a higher BAFO% values and Ost density for G3 in comparison with the other two groups (G1 and G2), with p < 0.05. However, the RTv and BIC% parameters were not significantly different between groups (p > 0.05). The histological data suggest that the healing chambers in the implant macrogeometry can improve the bone reaction in comparison with the conventional thread design.

New Implant Macrogeometry to Improve and Accelerate the Osseointegration: An In Vivo Experimental Study

“…Still, the healing chamber of group G3 presented a higher amount of BAFO%, indicating that the cellular reaction differed between the implant thread configurations. Other animal studies, where the healing chambers were examined in a longer time period (2 months), showed that healing chambers inserted in the cortical bone did not increase the BIC%, but increased implant biomechanical fixation at early times when compared to the conventional thread design [38]. This data sought in the literature helps to reinforce the initial hypothesis that the new implant design with the healing chambers elaborated in the implant threads more strongly in the initial stages of osseointegration of the implants.…”

Primary Stability of Dental Implants in Low-Density (10 and 20 pcf) Polyurethane Foam Blocks: Conical vs Cylindrical Implants

“…Regarding the macro-design, a cylindrical shape could lead to a higher bone-to-implant contact percentage, if compared with a conical geometry, providing that local factors such as depth of positioning, bone density, and surgical technique are equal [16,18,28]. Micro-geometry, threads pitch, and surface roughness could also significantly influence the primary stability [5,29,30].…”

Can changes in implant macrogeometry accelerate the osseointegration process?: An in vivo experimental biomechanical and histological evaluations

“…Thus, the present study had the aim of evaluated both implant models (regular and new implant mcrogeometry) with the same surface treatment, to verify the importance of this factor (the macrogeometry) in the early time period of osseointegration. Primary stability is a prerequisite for achieving osseointegration of implants [1,12,13,21,25,26]. This results from the mechanical union between the bone and the implant that minimizes micromovements between the two structures and prevents the formation of fibrous tissue at its interface.…”

“…In this sense, alterations in the micro-and macrogeometry of the implant design are presented [6][7][8]. New surface treatments (micro topography), changing the physical and/or chemical characteristics [6,9,10], and new macrogeometries changing the implant design [11][12][13], are created by the researchers and, posteriorly, manufactured by the industry. These changes have resulted in better biological performance, as demonstrated in previous preclinical studies [14][15][16].…”