A Custom-Made Orthodontic Mini-Implant—Effect of Insertion Angle and Cortical Bone Thickness on Stress Distribution with a Complex In Vitro and In Vivo Biosafety Profile

Abstract

Background: Orthodontic mini-implant failure is a debatable subject in clinical practice. However, the most important parameter to evaluate the success rate of mini-implant is the primary stability, which is mainly influenced by cortical bone thickness (CBT) and insertion angle. Materials and methods: Three-dimensional finite element models of the maxilla were created and a custom-made, self-drilling, tapered mini-implant was designed. For the pull-out test, 12 simulations were performed, sequentially increasing the thickness of the cortical bone (1, 1.5 and 2 mm) and the insertion angle (30°, 60°, 90°, 120°). For the force analysis, 24 simulations were performed using an experimental orthodontic traction force of 2 N both in the horizontal and vertical axis. Results: Insertion angle and CBT have significant impact on force reaction values (p < 0.05). Cortical bone stress had the lowest value when the mini-implant had a 30° insertion angle and the highest value when the implant had a 120° insertion angle, while the CBT was 1 mm. Cortical bone stress had the lowest value with an insertion angle of 90° and the highest value when the implant was inserted at an angle of 30°, while the CBT was 2 mm independent of the force direction. Regarding the biosafety profile of the mini-implant alloy, the present results reveal that the custom-made mini-implant presents good biocompatibility. Conclusions: When the CBT is reduced, we recommend inclined insertion while, when the CBT is appropriate, perpendicular insertion is advised.

Scaffold-Type Structure Dental Ceramics with Different Compositions Evaluated through Physicochemical Characteristics and Biosecurity Profiles

“…Additionally, metal alloys were studied and their bioavailability could be established by using the HET–CAM assay, with the possibility of analyzing the impact of certain metals released in the tested media [ 58 ]. In this regard, our research group recently demonstrated the lack of irritative potential and completed the biocompatibility data of dental materials such as mini-implants [ 25 , 39 ], thus confirming the benefits of this assay in toxicity studies for materials with topical application including dental use.…”

“…In brief, fertilized eggs from Gallus gallus domesticus were sprayed with ethanol (70%) to ensure disinfection of the eggshell and afterwards the eggs were placed in an incubator at 37 °C and high humidity. Further, a slightly modified protocol developed by our group was employed [ 25 , 39 ].…”

Effect of Different Head Hole Position on the Rotational Resistance and Stability of Orthodontic Miniscrews: A Three-Dimensional Finite Element Study

“…Contrarily, Liu et al [ 44 ] reported that mini-implant insertion with an oblique angle increased primary stability. Popa et al [ 15 ] used the finite element analysis to reveal that the cortical bone stress showed lowest value and highest stability when the mini-implant had a 30° implantation angle, and when the cortical bone thickness was 1 mm. Meanwhile, when the cortical bone thickness was 2 mm, the cortical bone stress had the lowest value with an implantation angle of 90°.…”

“…Reports indicate more effective correction of severe malocclusions and dentofacial discrepancies [ 1 , 2 , 3 , 4 ], such as en-masse retraction of anterior teeth [ 2 , 5 ], molar uprighting [ 6 ], maxillary expansion [ 7 , 8 , 9 , 10 ], skeletal open bite or deep bite correction [ 11 , 12 ], and anteroposterior discrepancy correction [ 13 , 14 ]. The successful use of TSADs in the clinic is highly related to their stability [ 15 , 16 , 17 ]. Several studies consider miniscrew design according to the requirements of clinical stability [ 18 , 19 , 20 , 21 , 22 , 23 , 24 ].…”

Comparative Toxicological In Vitro and In Ovo Screening of Different Orthodontic Implants Currently Used in Dentistry

“…It is also important to mention that the success rate of orthodontic implants is based on several key factors, such as the implantation procedure employed, dental material features, implant topography, and design [ 17 , 18 ].…”