Steel Brackets Research Articles

Comparison of shear bond strength of orthodontic stainless-steel brackets on temporary crowns fabricated by three different methods: An in vitro study

Different methods are available for making temporary restorations. The purpose of this study was to determine and compare the shear bond strength of orthodontic brackets on temporary crowns made by three different methods. In this experimental study, disc form samples (N=54) were made in dimensions 8×1mm, according to the manufacturer's instructions. In this study, we had three groups (N=18) based on manufacturing methods (3D printing, conventional, and CAD/CAM). Following surface preparation of the samples, the brackets were bonded in the centre of the discs. Before the shear bond strength test, the samples were subjected to the thermocycling process. The shear bond strength of brackets was measured by Universal Testing Machine. Data were analysed by one-way ANOVA and LSD post hoc test. The findings indicated that the mean shear bond strength of orthodontic stainless-steel brackets on temporary crowns varied between CAD/CAM and 3D printing methods (P<0.001) and also between CAD/CAM and conventional methods (P<0.001). The mean shear bond strength of orthodontic stainless steel brackets on temporary crowns was not different between 3D printing and conventional methods (P=0.7). The shear bond strength of orthodontic stainless-steel brackets bonded to temporary crowns fabricated by conventional and 3D printing methods was similar, and the shear bond strength in the samples fabricated by CAD/CAM method was lower than other specimens.

In vitro study of the antibacterial effect of plasma surface treatment using Argon gas on orthodontic stainless steel brackets against Streptococcus mutans and Lactobacillus acidophilus

Orthodontic treatment improves dental aesthetics. However, the prolonged duration of treatment and patient's oral hygiene results in more significant biofilm buildup and boosting concentrations of acidogenic bacteria, resulting in enamel demineralization. Plasma treatment technology has developed an interest in enhancing appliances' surface properties. The present study aimed to investigate cytotoxicity and antibacterial activity represented by anti-adhesion and anti-biofilm formation of Argon plasma treatment on orthodontic brackets against Streptococcus mutans and Lactobacillus acidophilus and evaluation the effect of change in plasma exposure duration on these properties in vitro. The study included three groups, group 1: untreated stainless steel brackets, group 2: brackets treated for 15 min, and group 3: brackets treated for 30 min. S.mutans and L.acidophilus were isolated from patients undergoing fixed orthodontic treatment. Microbiological tests included adhesion assay using plate counting method and biofilm formation assay using ELISA plate reader. S. mutans&amp; L. acidophilus were cultivated in three groups, and their adherence and biofilm formation were measured and compared. The biocompatibility of treated stainless steel brackets was evaluated by MTT assay. Results showed that groups 2 &amp; 3 had better anti-adhesion and anti-biofilm activity when compared with group 1, with a significant difference between group 1 &amp;group 3, in which group 3 recorded the lowest biofilm formation and the highest anti- anti-A adhesion activity. MTT showed that groups 2 and 3 exhibited more than 80% cell viability after 24, 48, and 72 hours. Plasma surface treatment of metal brackets possesses antibacterial activity against S.mutans and L.acidophilus; alteration exposure time impacts the development of these properties. Keywords. Plasma treatment, Argon gas, orthodontic brackets, biofilm, antimicrobial.

Yield mechanisms of base shear connections for cross-laminated timber shear walls

When cross-laminated timber (CLT) shear wall is designed for seismic loads, the Canadian timber design standard recognizes rocking as the sole energy dissipation kinematic mechanism to meet the capacity design requirement. The sliding mechanism, achievable by yielding of the base shear connections of CLT shear walls, is currently excluded. The focus of this research was on the yielding mechanism of base shear connections for mass timber shear walls as potential source for dissipating energy during major seismic events through sliding. Two types of base shear connections were evaluated: one was designed to exhibit ductile behavior through fastener yielding and the other was designed to yield within a perforated zone of steel bracket that was connected to the timber member with over-designed fasteners (i.e., capacity protected). In both cases, self-tapping screws (STS) were used as fasteners. Monotonic and cyclic tests were performed. The strength, stiffness, ductility, over-strength, and failure mechanisms were determined to investigate the use of these connections as reliable energy dissipating mechanisms. It was found that perforated steel plates provide a reliable yield mechanism with predictable yield and ultimate strength and displacement, and that damage in timber elements can be avoided when the fuses are combined with capacity-protected dowel-type fasteners. Both types of base shear connections under consideration behave in a ductile manner with some limitations under cyclic loading. While the perforated plate detail has the potential to qualify as moderately ductile connection, the other connection with fastener yielding mechanism may only exhibit limited ductility. An analytical model for predicting the yield and ultimate strengths, and ultimate deformation of the perforated plate was developed.

Comparative Evaluation of Frictional Resistance Between Different Types of Ceramic Brackets and Stainless Steel Brackets With Teflon-Coated Stainless Steel and Stainless Steel Archwires: An In-Vitro Study.

BackgroundOrthodontic tooth movement relies on sliding mechanics usually achieved by sliding the archwire through brackets. Sliding causes friction which is a force resisting the relative motion of two contacting objects. Frictional resistance is undesirable in orthodontic tooth movement because the archwire might bind with the bracket and prevent tooth movement. In addition, friction causes bending of the archwire leading to unwanted tooth movement or space loss through anchorage interference, prolonging the treatment time and root resorption. This study was performed to compare the frictional resistance produced by different types of ceramic brackets and stainless steel brackets with Teflon-coated stainless steel and stainless steel archwires. The surface texture of the wire before and after friction test was also evaluated using a scanning electron microscope (SEM).MethodologyA total of 48 samples were tested. In total, 12 premolar brackets each of stainless steel (Ortho technology, Carlsbad, CA, USA), monocrystalline ceramic (Ortho technology, Carlsbad, CA, USA), polycrystalline ceramic (Ortho technology, Carlsbad, CA, USA), and ceramic bracket with a metal slot (Ortho technology, Carlsbad, CA, USA) having an 0.022-inch slot were coupled with 0.019 × 0.025-inch stainless steel and Teflon-coated stainless steel wires. Each bracket-wire assembly was vertically mounted and clamped to the jaws of the universal testing machine. The wire was pulled across the bracket with a cross head speed of 10 mm per minute. The readings obtained were recorded. To evaluate the surface roughness, wires were examined using an SEM (in four magnifications 250×, 500×, 1,000×, and 5,000×) before and after testing.ResultsUnder the testing conditions, the stainless steel bracket-stainless steel wire combination produced the least frictional resistance, and the polycrystalline ceramic bracket-stainless steel wire combination produced the highest frictional resistance. Ceramic brackets with a metal slot generated lesser friction than other types of ceramic brackets but more friction than stainless steel brackets. Moreover, for all bracket-archwire combinations, Teflon-coated wires generated reduced frictional resistance compared to stainless steel wires. The surface examination of Teflon-coated stainless steel wire and conventional uncoated stainless steel wire revealed that Teflon-coated wire had a smoother surface compared to uncoated stainless steel wire.ConclusionsWithin the limitations of this study, it was concluded that the stainless steel bracket produced the lowest frictional resistance and the polycrystalline ceramic bracket produced the highest frictional resistance. Ceramic brackets with a metal slot showed a coefficient of friction that was more than but comparable to that of stainless steel brackets. Monocrystalline ceramic brackets generated lesser friction compared to polycrystalline ceramic brackets. Further, Teflon coating of stainless steel archwires can reduce frictional resistance compared to conventional uncoated stainless steel archwires. The surface of Teflon-coated stainless steel wires was found to be smoother than uncoated stainless steel wires.

Comparative Evaluation of Microleakage Under APC Plus, APC Flash-Free and Conventional Stainless Steel Brackets: An In Vitro Study

Aim: The aim of the study was to compare and evaluate the microleakage under the Adhesive Precoated Plus (APCP), APC Flash-Free (APCF), and conventional stainless steel (SLS) brackets on the occlusal and gingival sides of the bracket base. Materials and Methods: 66 extracted premolar teeth were collected and divided equally into 3 groups. Bonding was done with APCP, APCF, and conventional SLS brackets using Transbond XT. After bonding, the samples were stored in a distilled water and thermocycled for 3000 cycles, followed by immersion in a 2% methylene blue for 24 h. After cleaning, the teeth were mounted in acrylic and sectioned longitudinally at about the center of the bracket in a buccolingual direction. Microleakage was recorded using a stereomicroscope. Results: Kruskal–Wallis H test showed a significant difference ( P &lt; .005) in the microleakage scores between the 3 groups. Mann–Whitney U test showed a significant difference between group 1 to group 2 and group 1 to group 3 ( P &lt; .005) and an insignificant difference between group 2 and group 3 on the occlusal side ( P = .116) and on the gingival side ( P = .063). Conclusion: Conventional SLS bracket group exhibited greater microleakage scores at both occlusal and gingival sides, when compared with APCP and APCF groups.

Reducing Friction in Orthodontic Brackets: A Matter of Material or Type of Ligation Selection? In-Vitro Comparative Study.

(1) Background: Orthodontic appliances have changed and improved with the increasing demand for orthodontic treatment of the general population. Patients desire for shorter orthodontic treatments and for the wearing of more aesthetic devices has led to the technological development of orthodontic brackets; these were manufactured from aesthetic materials (ceramics, composite polymers) and presented different designs regarding the way archwires are ligated to the bracket. The aim of this study was to determine whether there were any differences between the static frictional forces generated by stainless steel (metallic) and polycrystalline alumina (ceramics) conventional and self-ligating brackets. (2) Methods: Static friction assessment was carried out in vitro with a universal testing machine, HV-500N-S (Schmidt Control Instruments, Hans Schmidt & Co. GmbH), intended for measuring compression and traction forces. (3) Results: The study revealed significant differences in static frictional forces at the bracket-archwire interface between the tested brackets. Stainless steel brackets produced lower static friction forces than polycrystalline alumina and self-ligating brackets generally produced lower static frictional forces than conventional brackets. The reduction of frictional forces was noticeable in the first stages of treatment, when thin, flexible orthodontic archwires (0.016” NiTi) are used. Engaged with large rectangular stainless steel archwires, (0.019 × 0.025” SS), the frictional forces produced by conventional and self-ligating metal brackets were similar, no significant differences being observed between the two types of metallic design. However, in the case of tested ceramic brackets, the results showed that the self-ligating type allows a reduction in frictional forces even in advanced stages of treatment compared to conventionally ligation. (4) Conclusions: From the perspective of an orthodontic system with low frictional forces, metal brackets are preferable to aesthetic ones, and self-ligating ceramic brackets are preferable to conventional ceramic brackets.

Artifacts in magnetic resonance imaging caused by dental materials: a systematic review.

The purpose of this systematic review was to search in literature in which severity unintended effects are caused by dental materials in magnetic resonance imaging (MRI), such as to evaluate whether these artifacts hamper the diagnosis in the head and neck region. Clinical studies showing the severity of artifacts which dental materials are capable of causing in MRI of head and neck, such as their influence on diagnostic accuracy, were included in this review. The searches were conducted in four electronic databases (PubMed/Medline, Embase, Scopus and Web of Science), and a manual search was made in the reference lists of papers screened for full-text reading. Risk of bias was assessed using "Quality Assessment Tool for Diagnostic Accuracy Studies-2" (QUADAS-2). The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) was used to assess the quality of evidence. From 151 studies selected for full-reading, 19 were considered eligible for this review. Artifacts caused by orthodontic appliances were well-documented, and stainless steel brackets were the materials most likely to cause artifacts in MR imaging of head and neck. The literature was scarce for dental implants and restorations. Diagnoses within the oral cavity, but also those of the brain and craniofacial structures, were affected. Artifacts caused by orthodontic appliances may affect the diagnosis in oral cavity and craniofacial structures. Data regarding dental implants and prosthodontics restorations were inconclusive. The severity of artifacts in MRI and their influence on diagnosis is dependent on dental material features, location in the oral cavity, and magnetic resonance parameters.

Parameter identification of ductile timber beam-to-steel column connections: Procedure and assessment

Ductile beam–column connections in a moment-resistant timber frame are essential part that can affect the seismic performance of the timber frame. As the first step, this study presents a ductile timber beam-to-steel column joint connected by a steel link, herein designed as a box-shaped steel bracket. A robust unscented Kalman filter (UKF) algorithm was presented to identify the model parameters of the proposed the connection. In addition, a dual-scale assessment method is proposed to evaluate the accuracy of the identified results. UKF algorithm is limited to the problem of nonpositive definite matrices in high dimensional parameter identification. To prevent the interruption of the program and improve the stability of the program, the Cholesky decomposition in the UKF was superseded by singular value decomposition (SVD), a noise estimator was embedded into the UKF to self-adapt the noise covariance matrix during the iteration. The assessment was carried out for both the steel links and timber beam-to-steel column connections. Subsequently the framework was introduced for the parameter identification of the steel links. For the hysteretic curves, performance indices, and energy dissipation, there was good agreement between the experimental and numerical results. The steel bracket improves the ductility of the timber beam-to-steel column connection. The average ductility coefficient of the steel bracket with ribs can reach 7.11. The proposed parameter identification procedure is verified to be applicable in the field of ductile timber beam-to-steel column connections. The program stability is improved and the error of most of the performance parameters is within 10%. However, this method still need to be verified for dynamic analysis in the whole building.

Salivary Electrolytes in Patients Undergoing Fixed Orthodontic Treatment

The base metal alloys are more susceptible to corrosion than nobl ealloys, and fixed orthodontic appliances are generally made of base alloys. Fixed orthodontic appliances in the oral cavity are exposed to destructive physical and chemical agents, resulting in metallic corrosion. The present study aimed to evaluate the concentration of cobalt, zinc, and magnesium in patients' saliva with fixed orthodontic appliances at three different times. Saliva samples from 18 patients (9 males and 9 females) between 15-25 years were taken at three different time points. Group I: Pretreatment saliva sample, group II: one month after appliance placement, Group III: four months after appliance placement. The fixed appliance consists of 20 stainless steel brackets, 4 buccal tubes, and a super elastic nickel-titanium arch wire. Inductively Coupled Plasma Optical Emission Spectrometry analyzed the level of ions in salivary samples. Ions are recorded in parts per billion. Statistical analysis was performed by non-parametric tests (Friedman) and one-way repeated measures ANOVA. Levels of cobalt, magnesium, and zinc ions in saliva were highest in group II, lowest in group I for both zinc and cobalt, and lowest in group III for magnesium. On a pair wise comparison between different groups, it was statistically significant for all groups (&lt;0. 005) except for cobalt and magnesium level between group I and group III and zinc level between groups II and III. Cobalt, magnesium, and zinc levels in saliva were increased after placing a fixed orthodontic appliance.

Investigation of the effects of orthodontic brackets coated by silver hydroxyapatite, copper oxide, and titanium oxide nanoparticles on wire-bracket friction

Objectives: Coating orthodontic brackets with metal nanoparticles seem to affect surface roughness and friction. We aim to compare the effects of coating brackets with copper oxide (CuO), titanium dioxide (TiO2), and silver hydroxyapatite (S-HAP) on friction between brackets and various sizes and materials of orthodontic wires. Material and Methods: In this experimental study, we selected four groups of stainless steel (SS) brackets with eight orthodontic wires (SS and nickel-titanium [Niti]) in different sizes. Three groups were coated with CuO, TiO2, and S-HAP nanoparticles using dip coating. Then, we attached a 100 g weight to the wires and hung it from the universal testing machine. The wire passed through the brackets at a speed of 0.5 mm/min for 25 s. Finally, the friction between wires and brackets was compared using a two-way analysis of variance. Results: The results showed that friction of brackets coated with TiO2 was significantly lower than S-HAP (P = 0.021) and did not differ significantly between CuO and the control (P = 1). Furthermore, friction between CuO brackets was not significantly different from other groups (P &gt; 0.05). Niti round wires had significantly lower friction with all brackets compared to 0.16 × 0.22 square inch Niti wire (p&lt; 0.05), which, in turn, showed significantly lower friction compared to 0.16 × 0.22 square inch stainless steel (SS) wire (P = 0.008). Conclusion: Coating brackets with TiO2 and CuO nanoparticles can reduce the friction Moreover, Niti round wires show the least friction compared to rectangular or SS wires with all types of brackets.

Assessment of the Effectiveness of Different Fluoride-releasing Bonding Agents on Prevention of Enamel Demineralization around Orthodontic Bracket: An In Vitro Study

The aim of the current research was to evaluate the efficacy of different fluoride-releasing bonding products in preventing enamel demineralization around orthodontic brackets by using a scanning electron microscope (SEM). This research was performed using 80 healthy human premolar teeth that were extracted in course of orthodontic therapy. Until use, the sample premolars were subjected to storage in 0.1% thymol. Each premolar was thereafter cleansed with pumice for 10 seconds. Stainless steel brackets for premolars were employed. The 80 samples were allocated at random to one of the four groups (20 in each) as follows: Group I, control; group II, Transbond Plus color change adhesive; group III, GC Fuji Ortho LC; and group IV, Vitremer. An hour following bonding, all samples were subjected to pH cycling at a temperature of 37°C for a 14-day period. The premolar teeth were assessed below SEM. Analysis was performed with the one-way analysis of variance. Statistical significance was set at a p-value less than 0.05. The extreme area of demineralization was abridged by the use of Transbond™ Plus color change adhesive (108.19 ± 0.68), trailed by GC Fuji Ortho LC (119.24 ± 0.37) use, Vitremer (121.56 ± 0.92) as well as the control group (141.88 ± 1.09) in that order. And there was a statistically significant difference found between the groups (p <0.001). Tukey's honestly significant difference (HSD) was employed in an overall comparison of mean areas of enamel demineralization, which depicted that differences were significant statistically with the exception of group III and group IV. The current research came to a conclusion that the Transbond Plus color change adhesive group was more potent in significant inhibition of demineralization areas in comparison to GC Fuji Ortho LC group and Vitremer group. In course of fixed orthodontic therapy, demineralization of enamel is an inherent occurrence. Multiple approaches are being continually developed to avoid the formation of white spot lesions (WSLs) that compromise esthetics and cause deprived remineralization that enhances the menace of dental caries. Bonding agents that can release fluorides are thus considered highly efficacious.

Comparative Antibacterial Efficacy of Orthodontic Brackets Coated with Titanium Dioxide, Copper Oxide, and Hydroxyapatite-Silver Nanoparticles Against Streptococcus mutans

Background: The development of dental caries around orthodontic brackets is a common complication of orthodontic treatment. Objectives: This study aimed to compare the antibacterial efficacy of stainless steel (SS) brackets coated with copper oxide nanoparticles (CuO-NPs), titanium dioxide nanoparticles (TiO2-NPs), and hydroxyapatite silver nanoparticles (HA-SNPs) against Streptococcus mutans. Methods: In this in vitro, experimental study, 20 orthodontic brackets were assigned to four groups (n = 5, each group). One group served as the no-intervention control group, and the brackets in the remaining three groups underwent dip coating with CuO-NPs, TiO2-NPs, and HA-SNPs &lt; 100 nm. The number of S. mutans colonies was counted after 24 h, one week, and one and three months. Data were analyzed using the Shapiro Wilk test, repeated measures ANOVA, and Bonferroni multiple comparisons test. Results: All three experimental groups exhibited similar antibacterial properties after 90 days of trial (P &gt; 0.05). Moreover, CuO-NPs had a greater inhibitory effect than TiO2-NPs on S. mutans after 24 h (P = 0.007). However, the inhibitory effect of HA-SNPs was not significantly different from that of TiO2-NPs (P = 0.259) or CuO-NPs (P = 0.224). Conclusions: Considering the similar antibacterial properties of all three coatings in the long term, all three types of nanoparticles can be used to coat orthodontic brackets to prevent caries. However, due to the high cost and difficult preparation of HA-SNPs and the slightly higher efficacy of CuO-NPs in the short-term, the latter may be preferred for this purpose.

The effect of nitrogen-doped titanium dioxide-modified stainless steel brackets on Streptococcus mutans.

To evaluate the effect of nitrogen (N)-doped titanium dioxide (TiO2) coated stainless steel brackets activated with natural visible light and dental operating lights on Streptococcus mutans concentration in the plaque of orthodontic patients at 30 and 60 days. A total of 30 patients were recruited for this split-mouth study; 60 upper lateral incisor brackets constituted the study sample. A total of 30 brackets (15 right and 15 left) were coated with N-doped TiO2 using the (radio frequency) magnetron sputtering method. Plaque samples were collected at 30 days and 60 days after appliance placement. S mutans concentration was evaluated using real-time polymerase chain reaction. At both time intervals, the concentration of S mutans in the control group was greater than that in the study group (P = .005). In both the study and the control groups, the S mutans concentrations significantly increased from 30 to 60 days (P = .005). N-doped TiO2, on exposure to natural visible light and dental operating light, was effective in reducing the plaque concentration of S mutans in orthodontic patients. The efficacy was better at 30 days than at 60 days after placing the orthodontic appliances.

In vitro study - Comparative evaluation of bond strengths of stainless steel brackets and ceramic brackets after curing with the argon laser and the conventional visible light

Aim:The purpose of this study was to compare the bond strengths of stainless steel brackets and ceramic brackets after treated with conventional visible light and argon laser.Methodology:Extracted 80 human premolar teeth were collected and stored in distilled water. They are classified into four groups. All teeth were placed in acrylic block where long axis of the tooth should be perpendicular to the mold's bottom. Teeth were subjected to ×10 magnification after debonding.Results:There is no statistically significant difference was found between the shear bond strength of argon laser and conventional visible light for stainless steel and ceramic bracket. Ceramic brackets had significantly increased bond strength than stainless steel brackets.Conclusion:Argon laser can be used for bonding orthodontic brackets using a visible light-cure orthodontic adhesive system, and ceramic brackets had significantly increased bond strength than stainless steel.

Frictional Resistance of Non Coated and Epoxy Coated Superelastic NiTi Wires used for Aligning in Three Types of Brackets

Introduction: Coated archwires are preferred in combination with aesthetic orthodontic brackets by orthodontists over non metallic aesthetic archwires. Studies evaluating the frictional properties of epoxy coated round superelastic Nickel Titanium (NiTi) archwires are limited to stainless steel brackets. Aim: To evaluate and compare the frictional resistance of an epoxy coated 0.016" superelastic NiTi archwire in stainless steel, composite and ceramic brackets and to compare it with the frictional resistance generated by non coated 0.016" superelastic NiTi archwire in same brackets. Materials and Methods: An in-vitro experimental study was conducted in the Department of Orthodontics at SRM Dental College from January to February 2020. Frictional resistance of 30 epoxy coated aesthetic 0.016" upper superelastic NiTi wires (G4™ Nickel Titanium, 0.016, Upper Trueform™ I, ToothColored) and 30 conventional 0.016" upper superelastic NiTi wires (G4™ Nickel Titanium, 0.016, Upper Trueform™) from G&amp;H® orthodontics while sliding across three different types of brackets were evaluated. Twenty stainless-steel (Gemini® 3M unitek, Monrovia, California), 20 composite (FLI® RMO, Denver, Colo.), and 20 gemini clear ceramic (Gemini clear ® 3M unitek, Monrovia, California) 0.022x0.028" Slot Roth prescription maxillary first premolar brackets were used. The brackets and archwires were divided into six groups of different bracket and archwire combination with 10 samples in each. An Instron testing machine with a 10 N tension was used to measure the frictional resistance. The obtained values were analysed using One-way ANOVA and followed by Post Hoc Tukey HSD for multiple comparison. Results: Coated wires generated significantly high friction in ceramic brackets (136.90±3.79 gms) followed by composite brackets (125.66±3.44 gms) and stainless steel brackets (92.53±8.70 gms). Non non coated wires generated significantly high friction with ceramic brackets (89.60±2.90 gms) whereas the friction generated in composite (70.87±5.79 gms) and stainless steel brackets (67.70±2.80 gms) was not significantly different. Conclusion: Epoxy coating increased the frictional resistance generated by the 0.016 superelastic NiTi archwires irrespective of bracket materials. The coated wires generated less friction in composite brackets compared to ceramic brackets. Further clinical trial are recommended to evaluate the aligning efficacy of these archwires in aesthetic brackets.

Economic 6-DOF robotic manipulator hardware design for research and education

This work proposes economic design of robotic manipulator hardware for education and laboratory experiment purposes. This prototype can be used for conducting experiments and validation of various control strategies like robust control design, artificial intelligence-based control design, vision-based control, etc. Designed 6-DOF robotic manipulator is connected to the computer system through Arduino board, which acts as a communication device. High torque DC servo motors are used to control each joint of the manipulator. Frame of the manipulator is designed with mild steel brackets. Robot operating system (ROS), an open-source meta operating system is used to control and perform series of operations on a robotic manipulator. Robotic manipulator is configured and controlled using the MoveIt package. MoveIt will plan the trajectory using inverse kinematics for desired goal state and the same can be visualized through Rviz. Experiment results show that robotic manipulator prototype successfully follow the trajectory planned by the MoveIt and reached to the desired goal state. Because of open-source alternatives like ROS, cost of the prototype design is economical and hence, the prototype can be utilized for experimental validation in research and laboratory purpose.

In vitro evaluation of surface characteristics comparing WaterLase (Biolase®) with tungsten carbide burs for composite removal: a pilot study

Abstract Introduction The present ex-vivo study was designed to evaluate the surface roughness and analyse potential adhesive remnants on the enamel surface after composite removal using either an Er:YSGG WaterLase (WL) (Biolase®, Irvine, CA, USA) or a tungsten carbide (TC) bur (Alston, England, UK). Methods An in vitro study was designed using 21 extracted lower premolars. Pre-coated stainless steel brackets (3M Unitek, Monrovia, CA, USA) were bonded on all of the teeth except one, which served as a control. The teeth were allocated into two groups: Group 1 (n = 5), removal of composite with a TC bur. Group 2 (n = 15), removal of composite using the WL. Scanning electron microscope (SEM) imaging and Energy Dispersive X-ray Spectroscopy (EDS) were used to determine the surface roughness and atomic composition of the surfaces. Results Group 1 had a median damage depth of 17.6 µm with a range between 11.5 µ m and 28.7 µ m. Group 2 had a median damage depth of 166.3 µ m, with a range between 86.6 to 263.1 µ m. The depth differences between the two groups were statistically significant (p &lt; 0.001, Mann–Whitney test). The atomic composition of the WL group was similar to sound enamel. The TC group showed a quantitative increase in carbon and silicone by 38.2% and 11.5%, respectively, a decrease in oxygen by 44.1% and an absence of phosphorous and calcium. Conclusion WL is efficient at removing composite from the enamel surface but could result in increased enamel surface roughness in comparison with conventional TC burs.

Effect of 8% arginine toothpaste on Streptococcus mutans in patients undergoing fixed orthodontic treatment: randomized controlled trial.

ABSTRACTObjective: To assess the effect of toothpaste containing 8% arginine on Streptococcus mutans (S. mutans) in dental plaque around orthodontic brackets, and to draw a comparison with a regular fluoride toothpaste. Trial design: A single-center, parallel-arm, triple-blind, randomized controlled trial was conducted. Methods: The clinical trial was conducted at the Orthodontic Clinic, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran. Seventy-two patients (age range: 15-30 years) who required fixed orthodontic treatment were recruited and randomly assigned to arginine and fluoride groups. Randomization was performed using RANDOM.ORG online software, and the participants were divided into two parallel groups, with a 1:1 allocation ratio. Patients were requested to brush their teeth twice daily for 30 days with an experimental toothpaste. Plaque sampling was performed at two intervals, namely at the beginning of the study (T0) and 30 days later (T1). Real-time PCR was used to assess plaque samples in terms of the number of S. mutans surrounding stainless steel brackets in orthodontic patients. A triple-blind design was employed. Results: The baseline characteristics (age, sex, and the relative number of S. mutans) between the groups were similar (p>0.05). Only the arginine group showed a significant decrease in the relative number of bacteria between T0 and T1 (p=0.02). Conclusion: Arginine is an important prebiotic agent in maintaining healthy oral biofilms, and prevent dental caries during fixed orthodontic treatments. Trial registration: The trial was registered at the Iranian Registry of Clinical Trials (IRCT20181121041713N2), https://en.irct.ir/user/trial/42409/view.

Causation of Oxidative Stress and Defense Response of a Yeast Cell Model after Treatment with Orthodontic Alloys Consisting of Metal Ions.

Misaligned teeth have a tremendous impact on oral and dental health, and the most efficient method of correcting the problem is orthodontic treatment with orthodontic appliances. The study was conducted to investigate the metal composition of selected orthodontic alloys, the release of metal ions, and the oxidative consequences that the metal ions may cause in the cell. Different sets of archwires, stainless steel brackets, and molar bands were incubated in artificial saliva for 90 days. The composition of each orthodontic material and quantification of the concentration of metal ions released were evaluated. Metal ion mixtures were prepared to determine the occurrence of oxidative stress, antioxidant enzyme defense system, and oxidative damage to proteins. The beta titanium alloy released the fewest metal ions and did not cause oxidative stress or protein damage. The metal ions from stainless steel and the cobalt-chromium alloy can cause oxidative stress and protein damage only at high concentrations. All metal ions from orthodontic alloys alter the activity of antioxidant enzymes in some way. The determined amounts of metal ions released from orthodontic appliances in a simulated oral environment are still below the maximum tolerated dose, and the concentrations of released metal ions are not capable of inducing oxidative stress, although some changes in antioxidant enzyme activity were observed at these concentrations.

Influence of orthodontic brackets and permanent retainers on the diagnostic image quality of MRI scans: A preliminary study.

Orthodontic treatment with fixed mechanotherapy using appliances and permanent retainers bonded after treatment is a routine procedure performed in clinical dentistry. Patients with braces or retainers sometimes need to undergo magnetic resonance imaging (MRI) for various reasons. Radiologists do not know the exact impact of the materials used in orthodontics on the diagnostic image quality of MRI scans. The aim of the study was to evaluate the influence of different types of orthodontic brackets and permanent retainers on the diagnostic image quality of MRI scans. Twenty patients with bonded brackets (stainless steel buccal/labial, stainless steel lingual, ceramic self-ligating with metal slots, ceramic, and polycarbonate) and 18 patients with bonded fixed retainers (titanium, fiber-reinforced composite, multi-stranded stainless steel, and different combinations of permanent retainers) participated in the study. The same adhesive was used for bonding. Cranial MRI scans of 6 regions were acquired for each subject, using a 1.5T MAGNETOM machine. Six radiologists evaluated the images and provided scores based on the modified receiver operating characteristic (ROC) analysis of distortion. The paired Wilcoxon signed-rank test was used to assess differences between the materials and the anatomic sites with regard to the distortion rating scale. Cohen's kappa coefficient (κ) was applied to establish the interrater reliability. A statistically significant difference was found between stainless steel brackets (both buccal/ labial and lingual) and all other experimental materials in terms of mean distortion scores (p = 0.020 or p = 0.024). The interrater reliability proved to be high. Stainless steel buccal/labial and lingual brackets caused maximum distortion of the images, which became non-diagnostic; hence, such brackets should be removed before MRI. Ceramic and polycarbonate brackets as well as fiber-reinforced composite retainers did not distort the images; thus, they need not be removed. Ceramic self-ligating brackets with metal slots, titanium retainers, multi-stranded stainless steel retainers, and combinations of fixed retainers caused minimal distortion; however, the images were still diagnostic. Hence, patients using these materials may not need to have them removed before MRI.