scholarly journals Drilling Capability of Orthodontic Miniscrews: In Vitro Study

2020 ◽  
Vol 8 (4) ◽  
pp. 138
Author(s):  
Alessandra Marchi ◽  
Matteo Camporesi ◽  
Maurizio Festa ◽  
Luis Salvatierra ◽  
Sara Izadi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bone Density ◽  
Structural Changes ◽  
In Vitro Study ◽  
The Self ◽  
Bone Block ◽  
Insertion Torque ◽  
Artificial Bone ◽  
Torque Values

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.

scholarly journals Influence of Orthodontic Anchor Screw Anchorage Method on the Stability of Artificial Bone: An In Vitro Study

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3205 ◽  
Author(s):  
Seen-Young Kang ◽  
Ji-Min Yu ◽  
Hyoung-Sik Kim ◽  
Jun-Seok Lee ◽  
Chan-Mi Yeon ◽  
...  
Keyword(s):  
In Vitro Study ◽  
Automatic Device ◽  
Insertion Torque ◽  
Artificial Bone ◽  
Artificial Bones ◽  
Significant Difference ◽  
The Mean ◽  
The Stability ◽  
Torque Values

This study aims to compare the torque values for various lengths of the titanium-based orthodontic anchor screw (OAS), different anchorage methods and varying artificial bone densities after predrilling. Furthermore, the effects of these parameters on bone stability are evaluated. A total of 144 OASs were prepared with a diameter of 1.6 mm and heights of 6, 8 and 10 mm. Artificial bones were selected according to their density, corresponding to Grades 50, 40 and 30. Torque values for the automatic device and manual anchorage methods exhibited a statistically significant difference for the same-sized OAS, according to the bone density of the artificial bones (p < 0.05). However, when insertion torque was at the maximum rotations, there was no significant difference in the torque values for the Grade 30 artificial bone (p > 0.05). When the torque values of both anchorage methods were statistically compared with the mean difference for each group, the results of the manual anchorage method were significantly higher than those of the automatic device anchorage method (p < 0.05). A statistically significant difference was observed in the bone stability resulting from different OAS anchorage methods and artificial bone lengths. These findings suggest that the automatic anchorage method should be used when fixing the OAS.

scholarly journals Torque Loss After Miniscrew Placement: An In-Vitro Study Followed by a Clinical Trial

2016 ◽  
Vol 10 (1) ◽  
pp. 251-260 ◽  
Author(s):  
Marco Migliorati ◽  
Sara Drago ◽  
Fabrizio Barberis ◽  
Irene Schiavetti ◽  
Domenico Dalessandri ◽  
...  
Keyword(s):  
In Vitro Study ◽  
Insertion Time ◽  
Controlled Environment ◽  
Insertion Torque ◽  
Experimental Setup ◽  
Percentage Difference ◽  
Torque Loss ◽  
Torque Values

To evaluate torque loss a week after insertion, both in an in vivo and an in vitro experimental setup were designed. In the in vivo setup a total of 29 miniscrews were placed in 20 patients who underwent orthodontic treatment. Maximum insertion torque (MIT) was evaluated at insertion time (T1). A week later, insertion torque was measured again by applying a quarter turn (T2); no load was applied on the screw during the first week. In the in vitro setup a total of 20 miniscrews were placed in pig rib bone samples. MIT was evaluated at insertion time (T1). Bone samples were kept in saline solution and controlled environment for a week during which the solution was refreshed every day. Afterwards, torque was measured again by applying a quarter turn (T2). The comparison of MIT over time was done calculating the percentage difference of the torque values between pre- and post-treatment and using the parametric two independent samples t-test or the non-parametric Mann–Whitney test. After a week unloaded miniscrews showed a mean loss of rotational torque of 36.3% and 40.9% in in vitro and in in vivo conditions, respectively. No statistical differences were found between the two different setups. Torque loss was observed after the first week in both study models; in vitro experimental setup provided a reliable study model for studying torque variation during the first week after insertion.

Influence of bone density and implant drill diameter on the resulting axial force and temperature development in implant burs and artificial bone: an in vitro study

2015 ◽  
Vol 20 (2) ◽  
pp. 135-142 ◽  
Author(s):  
Stephan Christian Möhlhenrich ◽  
Mustapha Abouridouane ◽  
Nicole Heussen ◽  
Ali Modabber ◽  
Fritz Klocke ◽  
...  
Keyword(s):  
Bone Density ◽  
Axial Force ◽  
In Vitro Study ◽  
Vitro Study ◽  
Artificial Bone ◽  
Temperature Development ◽  
Drill Diameter

scholarly journals Comparison of the primary stability of orthodontic miniscrews after repeated insertion cycles:

2020 ◽  
Author(s):  
Felipe Nenen ◽  
Nicolás Garnica ◽  
Víctor Rojas ◽  
Rodrigo Oyonarte
Keyword(s):  
Iliac Crest ◽  
In Vitro Study ◽  
Primary Stability ◽  
The Self ◽  
Insertion Torque ◽  
Resonance Frequency Analysis ◽  
It Value ◽  
Insertion Sites ◽  
Scanning Electron

ABSTRACT Objectives To compare the primary stability of miniscrews after repeated cycles of insertion through insertion torque (IT) measurements and resonance frequency analysis (RFA). Materials and Methods Sixty titanium miniscrews were divided into two groups according to the insertion protocol: one with predrilled sites and the other self-drilled into porcine iliac crest bone specimens. Each group had three cycles of reinsertion. After each insertion, the IT and RFA were measured. The IT was measured by using a torque meter, and the RFA was measured using the Osstell ISQ device. A total of five miniscrews of each group were selected for sequential assessment of the morphology of their tip and threads using scanning electron microscopy after each insertion cycle. Results No statistically significant differences were found in the IT values of miniscrews reinserted up to three times in the group with predrilled surgical sites. The IT value increased significantly with the number of reinsertions in the self-drilled group. The RFA value decreased as the number of insertions increased in both groups. Conclusions Under the conditions of this in vitro study, reinserting miniscrews deteriorates the integrity of their tip and thread. Reinsertion should be discouraged particularly when insertion sites are not predrilled.

Implant stability related to insertion torque force and bone density: An in vitro study

1995 ◽  
Vol 74 (6) ◽  
pp. 608-612 ◽  
Author(s):  
J. Tricio ◽  
D. van Steenberghe ◽  
D. Rosenberg ◽  
L. Duchateau
Keyword(s):  
Bone Density ◽  
In Vitro Study ◽  
Vitro Study ◽  
Insertion Torque ◽  
Implant Stability

scholarly journals Combining the effects of undersized drilling and bone density on implant insertion torque

2017 ◽  
Vol 15 (3) ◽  
pp. 201
Author(s):  
Bernardo Alievi Camargo ◽  
Daniel Becker Nunes ◽  
Aloísio Oro Spazzin ◽  
Leonardo Federizzi ◽  
Christian Schuh ◽  
...  
Keyword(s):  
Bone Density ◽  
Control Group ◽  
Insertion Torque ◽  
Preparation Technique ◽  
Artificial Bone ◽  
Low Bone Density ◽  
Drilling Technique ◽  
Torque Values ◽  
Density Methods ◽  
Conventional Drilling

Aim: This study evaluated the influence of surgical undersized drilling on insertion torque of an implant system at low bone density. Methods: Implant site preparations were made in two polyurethane foam blocks with different densities, where two preparation techniques were considered: Control group (C): conventional drilling, following the manufacturer’s instructions; and Group (E): undersized drilling, experimental technique using a final surgical drill with reduced diameter. The artificial bone blocks were selected based on density: D1 (0.64 g/cm3) and D2 (0.32 g/cm3). Three groups were considered according to the preparation technique and bone density used (n=10): CD1 – conventional drilling technique in artificial bone with higher density; CD2 – conventional drilling technique in artificial bone with lower density; and ED2 – undersized drilling in artificial bone with lower density. Externalhexagon implants (11 × 4 mm) were inserted and the insertion torque values were measured using a digital torque-meter. Data were submitted to one-way ANOVA followed by Tukey’s test (α=0.05). Results: The results showed significant statistical differences between groups (p<0.001), where the highest insertion torque was found for the Group CD1 (48.9 Ncm) followed by Group ED2 (22.6 Ncm) and Group CD2 (11.7 Ncm). Conclusions: The undersized drilling technique for implant site preparation leads to increased insertion torque on low bone density.

scholarly journals Primary Stability of Orthodontic Titanium Miniscrews due to Cortical Bone Density and Re-Insertion

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4433 ◽  
Author(s):  
Gi-Tae Kim ◽  
Jie Jin ◽  
Utkarsh Mangal ◽  
Kee-Joon Lee ◽  
Kwang-Mahn Kim ◽  
...  
Keyword(s):  
Bone Density ◽  
Cortical Bone ◽  
Morphological Changes ◽  
In Vitro Study ◽  
Primary Stability ◽  
Insertion Torque ◽  
Horizontal Resistance ◽  
Cortical Bone Density ◽  
Increasing Demand

The increasing demand for orthodontic treatment over recent years has led to a growing need for the retrieval and reuse of titanium-based miniscrews to reduce the cost of treatment, especially in patients with early treatment failure due to insufficient primary stability. This in vitro study aimed to evaluate differences in the primary stability between initially inserted and re-inserted miniscrews within different cortical bone densities. Artificial bone was used to simulate cortical bone of different densities, namely 20, 30, 40, and 50 pound per cubic foot (pcf), where primary stability was evaluated based on maximum insertion torque (MIT), maximum removal torque (MRT), horizontal resistance, and micromotion. Scanning electron microscopy was used to evaluate morphological changes in the retrieved miniscrews. The MIT, MRT, horizontal resistance, and micromotion was better in samples with higher cortical bone density, thereby indicating better primary stability (P < 0.05). Furthermore, a significant reduction of MIT, MRT, and horizontal resistance was observed during re-insertion compared with the initial insertion, especially in the higher density cortical bone groups. However, there was no significant change in micromotion. While higher cortical bone density led to better primary stability, it also caused more abrasion to the miniscrews, thereby decreasing the primary stability during re-insertion.

Reverse torque values of abutment screws after dynamic loading: The effects of sealant agents and the taper of conical connections

2020 ◽  
Author(s):  
Arda Ozdiler ◽  
suleyman dayan ◽  
Burc Gencel ◽  
Gulbahar Isık-Ozkol
Keyword(s):  
Dynamic Loading ◽  
Antibacterial Agent ◽  
In Vitro Study ◽  
Control Group ◽  
Silicone Sealant ◽  
Reverse Torque ◽  
The Stability ◽  
Torque Values ◽  
Chlorhexidine Gel

This in vitro study evaluated the influence of taper angles on the internal conical connections of implant systems and of the application of chlorhexidine gel as an antibacterial agent or a polyvinyl siloxane (PVS) sealant on the reverse torque values of abutment screws after dynamic loading. The current study tested four implant systems with different taper angles (5.4°, 12°, 45°, and 60°). Specimens were divided into three groups: control (neither chlorhexidine gel filled nor silicone sealed), 2% chlorhexidine gel-filled or silicone-sealed group, and group subjected to a dynamic load of 50 N at 1 Hz for 500,000 cycles prior to reverse torque measurements. Quantitative positive correlation was observed between the taper angle degree and the percentage of tightening torque loss. However, this correlation was significant only for the 60° connection groups except in the group in which a sealant was applied ( p = 0.013 for the control group, p = 0.007 for the chlorhexidine group). Percentages of decrease in the torque values of the specimens with silicone sealant application were significantly higher compared with both the control and chlorhexidine groups ( p = 0.001, p = 0.002, p = 0.001, and p = 0.002, respectively, according to the increasing taper angles); the percentage of decrease in torque values due to chlorhexidine application was statistically insignificant when compared with the control group. The application of gel-form chlorhexidine as an antibacterial agent does not significantly affect the stability of the implant–abutment connection under dynamic loads. PVS sealants may cause screw loosening under functional loads.

Behavior of implant and abutment sets of three different connections during the non-axial load application: An in vitro experimental study using a radiographic method

2021 ◽  
pp. 1-12
Author(s):  
Sergio Alexandre Gehrke ◽  
Berenice Anina Dedavid ◽  
José Manuel Granero Marín ◽  
Luigi Canullo
Keyword(s):  
Experimental Study ◽  
Digital Radiography ◽  
Axial Load ◽  
In Vitro Study ◽  
Vitro Study ◽  
Load Application ◽  
Radiographic Method ◽  
Radiography System ◽  
Torque Values

BACKGROUND: During the masticatory cycle, loads of different intensities and directions are received by the dental structures and/or implants, which can cause micromovements at the junction between the abutment and implant. OBJECTIVE: The objective of this in vitro study was to evaluate the behavior of three different implant connections subjected to different load values using a digital radiography system. Additionally, the torque values for removing the abutment screws were also measured and compared. METHODS: Ninety sets of implant and abutment (IA) were used, divided into three groups according to the type of connection (n = 30 per group): EH group, external hexagon type connection; IH group, internal hexagon connection; and, MT group, Morse taper connection. RESULTS: MT group showed the better vertical misfit behavior at the three intensity of load applied, in comparison with EH and IH groups. In the analysis of torque maintenance (detorque test), MT group showed higher values of detorque when compared with the measured values of EH and IH groups (p < 0.001). CONCLUSIONS: The IA sets of EH and IH groups showed a microgap in all levels of applied loads, unlike the MT group this event was not observed. In the detorque test, MT group increase in the torque values when compared to the initial torque applied, unlike EH and IH groups showed a decrease in the initially torque applied in all conditions tested. A positive correlation was detected between the misfit and detorque values.

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