Bone response to orthodontic loading of endosseous implants in the rabbit calvaria: early continuous distalizing forces

Abstract

The purpose of this experimental study was to evaluate the effect of early orthodontic loading on the stability and bone-implant interface of titanium implants in a rabbit model. Twenty-four short threaded titanium fixtures were inserted in the calvarial mid-sagittal suture of 10 rabbits. Two weeks following insertion, 20 implants (test group) were subjected to continuous distalization forces of 150 g for a period of 8 weeks. The remaining four implants (control group) were left unloaded for the same follow-up interval. Clinically, all implants except for one test fixture were stable, and exhibited no mobility or displacement throughout the experimental loading period. Histologically, all stable implants were well-integrated into bone. No differences could be found between the pressure and tension surfaces of the test implants relative to bone quality and density within a range of 1000 microns from the fixture surface. Similarly, qualitative differences were not observed between the apical and coronal portions of test fixtures. Morphometrically, a mean percentage bone-to-implant contact of 76.00 +/- 18.73 per cent was found at the test pressure sides, 75.00 +/- 11.54 per cent at the test tension sides, and 68.00 +/- 15.55 per cent at the control unloaded surfaces. No statistically significant differences in the percentage of bone-to-metal contact length fraction were found between test pressure surfaces, test tension surfaces, and unloaded control surfaces. Marginal bone resorption around the implant collar or immediately beneath it was found in roughly the same percentage of analysed sites in the test and control fixtures. In contrast, slight bone apposition was demonstrated at the implant collar of the test pressure surfaces, while no apposition or resorption were observed in the test tension zones. This study suggests that short endosseous implants can be used as anchoring units for orthodontic tooth movement early in the post-insertion healing period.

Long-term follow-up of dental single implants under immediate orthodontic load

“…[16][17][18] The magnitude of force applied was the same described by several authors as being secure. 2,5,[19][20][21][22][23][24][25][26][27] Moreover, a 200 g force is considered appropriate to various orthodontic movements and potentially safe. In this study, the handles of two dental mirrors were used to evaluate whether there was absence of implant mobility.…”

Micro-CT and histologic analyses of bone surrounding immediately loaded miniscrew implants: Comparing compression and tension loading

“…Histologic analysis by Chen et al 15) showed that remodeling and bone apposition were slightly more active in the loaded specimens than the unloaded specimen. Majzoub et al 13) reported slight bone apposition in the compression region but not in the tension region. Aldikaçti et al 22) showed a corticalization of trabecular bone in the loaded compared to the unloaded specimen.…”

“…A variety of factors that may affect the primary stability and success rate of miniscrew implants, such as implant dimension 3,7) , implant length 8) , insertion orientation 9) , insertion torque 10) , and cortical bone thickness 11,12) , have been investigated. However, since immediate or early loading shortens the treatment period, with great clinical benefits for the orthodontist and patient, the effects of immediate loading have been histologically investigated for both self-tapping and self-drilling miniscrew implants [13][14][15][16][17] . A recent histologic investigation reported that immediate loading does not affect osseointegration of the miniscrew implant 15) .…”

“…A recent histologic investigation reported that immediate loading does not affect osseointegration of the miniscrew implant 15) . Several studies 13,15,17) reported that remodeling or bone apposition was slightly more active in the compressive loaded region than the tension-loaded or unloaded regions. In addition, a recent study 18) examined the effect of immediate loading on the biomechanical properties of bone surrounding the miniscrew implant by nanoindentation testing and reported that the implant bone interface region on the compression side of trabecular bone showed significantly greater hardness compared with other locations.…”

Impact of anchorage miniscrews in multibracket treatments without extractions

“…Since the very first clinical articles 56,70 , a great number of other treated cases have been published with sometimes outstanding results 1,2,[31][32][33]36,52,57,66,67 . The list of comparative studies 7,21,30,39,44 , experimental studies 26,45,51 , some randomized clinical trials 7,35,38,71 and systematic reviews 14,16,20,22,43 has continued to grow over the years. This can be seen as evidence for an ongoing therapeutic revolution that is impacting all aspects of orthodontics and that is suggesting new solutions for the buccal technique 8,15,28,34,36,46,55 as well as for lingual orthodontics 4,29,37,41,69 , for the aligner technique 11,73 or for orthopaedics 13 .…”