Effect of cortical bone thickness and density on pullout strength of mini-implants: An experimental study

Elibol, Fatma Kübra Erbay; Oflaz, Emre; Buğra, Emine; Orhan, Mehmet; Demir, Teyfik

doi:10.1016/j.ajodo.2019.02.020

Cited by 16 publications

(8 citation statements)

References 19 publications

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“…They are characterized by greater primary stability and a better BIC (bone implant contact); their insertion causes the creation of numerous bone fragments between the coils that can be interpreted as evidence that the bone is not compressed, but etched [28]. The miniscrews analyzed do not require predrilling, so they are under greater mechanical stress during the insertion [22,29]. Pre-and post-insertion morphostructural assessment performed with stereomicroscope and SEM showed no modification for all the miniscrews tested.…”

Section: Discussionmentioning

confidence: 98%

“…The authors of this article applied 40 miniscrews in four different substrates that simulated four different clinical conditions of human bone [29].…”

Section: Discussionmentioning

confidence: 99%

“…These values are like those reported in a recent study where the authors tested pullout strength of self-drilling miniscrews in samples with different cortical thicknesses. However, in the study the authors do not specific the means utilized to measure the insertion torque [29]. The insertion site with the optimal anatomical properties, according to some authors, is the vestibular bone corresponding to the distal root of the second molar, with a 4 mm vestibular screw inserted at the enamel-cement junction [2,10,32].…”

Section: Discussionmentioning

confidence: 99%

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Drilling Capability of Orthodontic Miniscrews: In Vitro Study

et al. 2020

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The aims of this study were to assess the values and mechanical properties of insertion torque (IT) of steel miniscrews inserted in artificial bone blocks (Sawbones, Pacific Research Laboratories, Vashon, WA, USA) with different bone densities and to detect any scratches on the surface of the miniscrews after insertion. Forty self-drilling miniscrews (Leone S.p.A. ø 1.75 mm, L 8 mm) have been inserted into bone blocks that mimic different stability conditions (density: 20 PCF—pounds per cubic foot, 40 PCF, and 30 + 50 PCF with 2 mm and 4 mm of cortical bone). Before insertion and after removal, all miniscrews were inspected with a stereomicroscope 5x and a SEM to detect potential microscopic cracks. Using an electronic surgical motor (W&H Dentalwerk Bürmoos GmbH, Werner Bader Str. 1, 5111 Bürmoos, Austria), the maximum insertion torque value was registered. Stereomicroscope and SEM examination did not indicate any morphological and surface structural changes to the miniscrews, irrespective of the bone density they were inserted into. The findings showed that IT increased significantly with increasing bone density. In each artificial bone block, morphostructural analysis demonstrated the adequate mechanical properties of the self-drilling miniscrews. IT measurements indicated torque values between 6 and 10 Ncm for blocks with a density of 30 + 50 PCF, whereas the suggested values are between 5 and 10 Ncm.

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Section: Discussionmentioning

confidence: 98%

“…The authors of this article applied 40 miniscrews in four different substrates that simulated four different clinical conditions of human bone [29].…”

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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Drilling Capability of Orthodontic Miniscrews: In Vitro Study

et al. 2020

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“…Chapman et al [19] determined that increasing the thread depth using a porous material produced a greater pullout strength and pullout resistance. The thickness of the cortical bone has been positively correlated with the primary stability of an implant [7,8]. In the HPS test, we discovered that the cortical bone must be destroyed before the microimplant can be pulled out.…”

Section: Discussionmentioning

confidence: 99%

“…The mechanical properties of a microimplant are key factors that determine its stability and success. Several factors, such as insertion torque (IT) [3], removal torque [4], microimplant geometry [5], and pullout strength [6][7][8], can be measured to determine the stability of microimplants. The reason for microimplant failure in the initial stage is that the mechanical interlocking strength between the bone and the microimplant weakens after orthodontic force is applied.…”

Section: Introductionmentioning

confidence: 99%

Effect of Microimplant Neck Design with and without Microthread on Pullout Strength and Destruction Volume

et al. 2021

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The microthread neck concept has been applied to dental implants. This study investigated the pullout strength and destruction volume of orthodontic microimplants with and without the microthread neck design. Fifteen microimplants (diameter: 1.5 × 10 mm) of three types (Types A and B: without microimplant neck; Type C: with microimplant neck) were tested. The insertion torque (IT), Periotest value (PTV), horizontal pullout strength (HPS), and horizontal destruction volume (HDV) of each type were measured. Kruskal–Wallis H test and Dunn’s post-hoc comparison test were performed to compare the measured values of the three types of microimplants. The correlations of the measured values were used to perform the Spearman’s correlation coefficient analysis. The ITs of Types B (8.8 Ncm) and C (8.9 Ncm) were significantly higher than those of Type A (5.2 Ncm). Type B yielded the lowest PTV (4.1), and no statistical differences in PTV were observed among the three types. Type A had a significantly lower HPS (158.8 Ncm) than Types B (226.9 Ncm) and C (212.8 Ncm). The three types did not exhibit any significant differences in the HDV. The results of the Spearman’s correlation coefficient test revealed that HDV (ρ = 0.710) and IT (ρ = 0.813) were strongly correlated with HPS, whereas for PTV and HPS, it was not. HPS was strongly and significantly correlated with HDV. The orthodontic microimplant with a microimplant neck design did not perform better than that without a microthread in the mechanical strength test.

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