Orthodontics in its century of existence have had a lot of landmarks in its evolution, but very few can match the clinical impact made by micro-implants and the recently introduced infra-zygomatic crest & buccal shelf orthodontic bone screws. Micro-implants and extra-radicular BS have brought about a renaissance to the field of orthodontics with its concept of absolute anchorage in the past decade. It is an added armamentarium in the hands of an experienced clinician to overcome new clinical challenges and convert even borderline surgical cases to nonsurgical without, compromising with the results achieved. Aim It is a FEM study in which buccal shelf screws are inserted in buccal bone lateral to the distal root of the 2nd molar and 4 mm buccal to the CEJ with different retraction forces and various angulation to study stress pattern in MBS area. Material and Method CBCT 3D image of the study mandible is made and the image transfer to the software. A FEM is created using a dedicated software. Orthodontic buccal shelf screws which is made of titanium alloy (diameter, 2 mm; length, 12 mm; thread ridge height, 0.2 mm; thread pitch, 0.6 mm). Miniscrew implant insertion is designated at 30°, 40°, 60°, 70°, and 90° angulations, and at each angulation a horizontal load of 150, 200, and 250 g is applied. Results BSS when inserted in buccal bone 60-70 degree angulation showed the least stress pattern in mandibular buccal shelf area and 40 – 50 degree angulation showed maximal stress distribution pattern.
: Bonded retainers are extensively used after orthodontic treatment to maintain the achieved results. However, bond failure in the retainer system is a frequently observed problem, resulting in the loss of retainer function, leading to relapse.: The purpose of this in-vitro study was to compare the shear bond strength of different wire-composite combinations.: 144 extracted human premolars in pairs were divided into 6 groups of 12 samples each. The orthodontic retainer wires used were Flat woven wire (Leone), Dead soft retention wire (Ortho Classic USA) and two stranded twisted Leone ligature wire (0.018”). The composite that was used was Transbond XT adhesive (3M Unitek) and Enlight Light Cure Adhesive (Ormco). Retainer wires were bonded on the lingual surfaces of the teeth. 72 samples were subjected to debonding with a chisel head in a universal testing machine INSTRON. Comparisons of the means of shear bond strength values were made with one way ANOVA & Tukey’s Post Hoc test.: Maximum shear bond strength was observed in group IA (Leone flat woven wire with Transbond XT). There was a statistically significant difference in the shear bond strength of different retainer wires.: Compared to other wire composite combinations, maximum shear bond strength was observed in Leone flat woven wire with Transbond XT composite. Therefore, it could be the wire-composite combination of choice for the bonded lingual retainer.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.