Multistranded Stainless Steel Research Articles

Stability and failure rate during 3 years of fixed retention: A follow-up of an randomized clinical trial on adolescents with four different lingual retainers.

To evaluate stability outcomes and failure rates associated with four types of lingual retainers: (1) dead-soft wire, (2) multistrand stainless steel (SS) wire, (3) CAD/CAM nitinol, and (4) connected bonding pads (CBPs) after 3 years of retention. This study enrolled 96 patients (66 females, 30 males) with a median age of 19 years with four types of lingual retainers: (1) 0.016 × 0.022-inch dead-soft wire, (2) 0.0215-inch five-strand SS wire, (3) 0.014 × 0.014-inch CAD/CAM nitinol wire, and (4) CBPs. The irregularity index, intercanine distances, and arch lengths were obtained and used to evaluate mandibular stability. Failure rates were also assessed during this study. Data were statistically analysed. Irregularity increased, whereas intercanine width and arch length decreased after 3 years of retention. The greatest irregularity was associated with the CBPs and the least with the CAD/CAM retainers. Changes in stability measurements were significantly higher in the dead-soft wire and CBPs than those in the CAD/CAM nitinol and multistrand SS wires. Parallel to these changes, the frequency of failure yielded similar results with the same significance between the groups. The failure rate of CBPs, in contrast to the CAD/CAM nitinol and multistrand SS wires, was significantly higher in the right quadrant (P < .05). After taking the 3-year results into consideration, CAD/CAM nitinol and multistrand SS wires were found to be more successful than the others in maintaining mandibular stability. The most failures were observed with CBPs after 3 years of retention.

Efficacy of CAD/CAM Technology in Interventions Implemented in Orthodontics: A Scoping Review of Clinical Trials.

Objectives To evaluate the efficacy of computer-aided design/computer-aided manufacturing (CAD/CAM) technology in interventions implemented in orthodontics. Methods A scoping review of scientific evidence was accomplished, involving different databases. MesH terms and keywords were provided to examine clinical trials (CTs) in all languages. Exclusively CTs that fulfilled the eligibility criteria were admitted. Results Eight CTs were chosen. These experiments evaluated 542 patients. Four CTs compared the computer-aided indirect bonding method versus the traditional direct bonding of orthodontic brackets. Three CTs compared CAD/CAM retainers with other types of retainers, and one CT compared the CAD/CAM group with multistranded stainless steel wires versus stainless steel wires. Regarding the efficacy of the interventions with CAD/CAM technology used in orthodontics, variable results were found. The indirect bonded customized CAD/CAM brackets presented just a slight effect on the treatment efficacy and therapy results. Two CTs showed that an indirect bonding self-ligating standard system had a similar quality of therapy in comparison with the CAD/CAM customized bracket system. Concerning the clinical failure rate, no differences were presented between the CAD/CAM retainer and other retainers. A CAD/CAM system had more loose brackets than a noncustomized system and was observed also a greater amount of immediate debonding with CAD/CAM indirect bonding than with direct bonding. CAD/CAM fixed retainers revealed inferior relapse and fewer failures than lab-based and conventional chairside retainers. No changes between treatment groups were observed regarding the total therapy time, amount of appointments, and quantity of archwire bends. Conclusions In general terms, no greater efficacy of CAD/CAM technology was observed over traditional therapies used in orthodontics. However, it was found that gingival inflammation and the accumulation of bacterial plaque and dental calculus were lower when CAD/CAM retainers were used. When comparing interventions that include CAD/CAM systems with conventional therapies, no significant reduction in care times was found.

Orthodontic treatment for crowded teeth in children.

Orthodontic treatment for crowded teeth in children.

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.

Comparative assessment of relapse and failure between CAD/CAM stainless steel and standard stainless steel fixed retainers in orthodontic retention patients.

To compare relapse and failure rates of computer-aided design/computer-aided manufacturing (CAD/CAM) and standard fixed retainers. This single-center, single-blinded, prospective randomized clinical trial included 46 patients who completed active orthodontic treatment and complied with retention visits. The patients were randomly assigned to three groups: CAD/CAM group with multistranded stainless steel wires (CAD/CAM, n = 16), Lab group with the same multistranded wires (lab, n = 16), and control group with stainless steel Ortho-FlexTech wires (traditional, n = 14). Intraoral scans were obtained at placement of fixed retainers (T1), 3-month visit (T2), and 6-month visit (T3) and measured for intercanine width and Little's Irregularity Index. Failures were recorded. The CAD/CAM group experienced less intercanine width decrease than the traditional group at 3 months (mean difference, 0.83 ± 0.16 mm; 95% confidence interval [CI], 0.44-1.22; P < .001) and 6 months (mean difference, 1.23 ± 0.40 mm; 95% CI, 0.19-2.27; P < .05). The CAD/CAM group experienced less increase in Little's Irregularity Index compared with the lab group within 3 months (mean difference, 0.81 ± 0.27 mm; 95% CI, 0.12-1.49; P < .05). Failures from greatest to least were experienced by the lab group (43.8%), the CAD/CAM group (25%), and the traditional group (14.3%). Within 6 months of bonding fixed retainers, CAD/CAM fixed retainers showed less relapse than lab-based and traditional chairside retainers and less failures than lab-based retainers.

Advances in orthodontic archwires

Recent advances in orthodontic wire alloys have resulted in a varied array of wires that exhibit a wide spectrum of properties. Up until the 1930s, the only orthodontic wires available were made of gold. Subsequently, stainless steel was introduced and due to its superior properties gained popularity over gold. The introduction of nickel-titanium archwires revolutionized the orthodontic field with their shape memory &amp; superelasticity. Several other alloys with desirable properties have been adopted in orthodontics. These include cobalt-chromium, beta titanium and multi-stranded stainless steel wires. The availability of archwires with widely diverging properties has profound implications on appliance mechanics and can be used to advantage at different stages of orthodontic treatment. The newer archwires score over conventional wires in terms of efficiency, total treatment time, and finishing. Also, the current emphasis on esthetic treatment options in orthodontics has led to the development of esthetic archwires. Presently the orthodontist may select, from all the available wire types, one that best meets the demands of a particular clinical situation. The selection of an appropriate wire size and alloy type in turn would provide the benefit of optimum and predictable treatment results.

Comparing the effects of CAD/CAM nickel‐titanium lingual retainers on teeth stability and periodontal health with conventional fixed and removable retainers: A randomized clinical trial

The objectives of this study were to evaluate the effect of a CAD/CAM nickel-titanium retainer on the stability of mandibular anterior teeth and periodontal health and to compare it with other retainers. Sixty participants from both genders who had irregularities prior to orthodontic therapy and who had been treated with full-fixed appliance mechanotherapy were included in the study and randomly allocated into four groups: CAD/CAM NiTi, multi-stranded stainless steel, single-stranded nickel-free titanium and vacuum-formed removable retainer groups. The mean age of the participants at the end of the treatment was approximately 20years. Digital impressions were taken for all participants at three different times: immediately (T0 ), three months (T1 ) and six months (T2 ) after treatment. Irregularity index, inter-canine and inter-molar width, and arch length were recorded using software. Additionally, a full periodontal assessment was carried out at T2 . During the follow-ups, all groups showed some relapse in the lower anterior teeth. No statistical significance was found intergroup in terms of all measured values. Within the multi-stranded group, inter-canine width had decreased by 0.10mm with a statistical significance (P=.048). An additional statistical significance with P=.045 was found within the single-stranded group regarding the increased arch length. The periodontal assessment results of the mandibular anterior teeth between groups did not show clinically significant differences. No statistical significance was found between the CAD/CAM retainer and other retainers regarding the clinical failure rate. Less plaque accumulation and gingival inflammation were observed in the CAD/CAM NiTi retainer group.

Evaluation of Mandibular Arch Width Changes following Fixed Retention in Post Orthodontic Patients - a Randomized Clinical Trial

Background: Retention is an integral phase in which teeth are maintained in their newly adapted position for which retainers are inserted. Retainers are generally of two types: removable and fixed. Fixed retainers are indicated in the mandibular arch for an indefinite period specifically in the non-extraction cases. Changes in intercanine and intermolar widths are valuable parameters to evaluate the stability. The objectives of this study were to assess and compare the mandibular intercanine and intermolar width changes following orthodontic treatment after insertion of two types of fixed lingual retainers for one year. Methods: Total 54 subjects were recruited in which two types of fixed lingual retainers were inserted in the mandibular arch randomly. Intercanine and intermolar arch widths were measured by digital caliper of 0.01 mm accuracy. Data was analyzed by using Statistical Package of Social Sciences (SPSS V-21). Chi-square and independent t tests were used to compare baseline characteristics. Intercanine and intermolar widths were assessed and compared using independent t test, p-value ≤ 0.05 is considered as statistically significant. Results: Intercanine width increased from baseline to T4 in both retainers. When mean differences of intercanine width were compared between two retainers significant differences were observed at T1, T2, T3 and T4 with significant p-values (&lt; 0.05) and increased intercanine width with multistranded stainless steel wire (MSW) retainers. Conclusion: Mandibular intercanine width increases significantly in post retention phase with multistranded stainless steel retainers. Thus, fiber reinforced composite retainers are more effective in preserving the arch width changes.

\u201cClinical comparison of bond failure rate between two types of mandibular canine-canine bonded orthodontic retainers- a randomized clinical trial\u201d

BackgroundBonded retainers are widely used as they are esthetically pleasing, easily acceptable, provide greater stability, compliance free and causes no soft tissue irritation and speech problems. Though, fracture and bond failure are their shortcomings. Therefore, the objectives of this study were to evaluate the number of bond failures and type of failure pattern between two types of mandibular canine-canine bonded retainers.MethodsTotal 60 subjects were recruited initially and were assessed for eligibility, out of which 6 were excluded and 2 were lost to follow up. They were randomly divided into two groups. Fiber reinforced composite (FRC) retainers were inserted in group 1 subjects while group 2 subjects received multistranded stainless steel (MSW) retainers. The subjects were recalled after every 3 months over a period of 1 year. Bond failure rate and failure pattern based on adhesive remnant index were evaluated at each visit. The bond failure rate and failure pattern were compared between the two retainers by using Chi-square test.ResultsThe bond failure rates were 42.94% for FRC retainer and 31.41% for MSW retainer. Hence, total number of bond failures in both retainers were 37.17%. The difference of bond failure between two groups was statistically significant (p = 0.012). Type “0” failure pattern was detected commonly with both types of retainers (p < 0.001).ConclusionOur findings indicate that multistranded stainless steel wire retainer is a superior option to be used for fixed lingual retention in mandibular arch as it exhibited lower bond failure as compared to fiber reinforced composite retainer. Adhesive failure is the most common type of bond failure observed with both types of fixed retainers.Trial registrationID NCT03881813 (https://clinicaltrials.gov/); March 19, 2019, retrospective registration.

Effectiveness of Two Types of Fixed Lingual Retainers in Preventing Mandibular Incisor Relapse.

To compare and evaluate the relapse tendency of two types of fixed lingual retainers using Little's irregularity index for a follow-up of one year. Randomised clinical trial. Department of Orthodontics, Dr. Ishrat Ul Ebad Khan Institute of Oral Health Sciences and Dow Dental College in Dow University of Health Sciences, Karachi, Pakistan, from November 2017 to March 2019. A total of 54 patients were recruited and divided into two groups by random allocation. Subjects who have completed fixed appliance (MBT) orthodontic treatment and non extraction cases with moderate crowding in the lower arch were included. Subjects with caries, restoration, fracture or missing lower anterior teeth were excluded. Group 1 received fiber reinforced composite (FRC) retainers and group 2 received multistranded stainless steel (MSW) retainers. They were recalled after every three months interval for one year. Relapse tendency of retainers using Little's irregularity index was evaluated at each visit. Comparison of relapse tendency between two retainers showed statistically significant results (p<0.05). The mean difference of CPD between two retainers at T0 was found to be 0.09 mm (p=0.01). At T1, it was determined to be 0.3 mm (p=0.022), and at T2 it was found to be 0.3 mm (p=0.008). At T3 and T4, it was found to be 0.5 mm (p<0.001) and 0.5 mm (p=0.002), respectively. All mean differences were statistically significant. Fiber-reinforced retainers are more effective in preventing the mandibular incisor relapse. The results of the study also suggest that the irregularity of the dentition increases with the passage of time.

What are the best materials to use for the first arch wire in orthodontic treatment?

Data sources Six electronic databases/registries including Medline, Cochrane Central Register of Controlled Trials (CENTRAL), Cochrane Oral Health's Trials Register, Embase, World Health Organization International Clinical Trials Registry Platform and The US National Institutes of Health Trials Registry (ClinicalTrials.gov) were searched up to October 2017. No restrictions of language or publication date were set.Study selection Only randomised controlled trials (RCTs) assessing the efficiency of initial arch wires to align teeth with fixed orthodontic braces in either or both upper and lower arches.Data extraction and synthesis Two reviewers abstracted data independently. Risk of bias was assessed using the Cochrane Collaboration Risk of Bias tool. Rate of alignment was considered the main outcome. Root resorption and pain level were considered adverse effects. Meta-analysis was performed when possible. Results Twelve RCTs involving 799 participants were included. Three studies were judged at high RoB, six were unclear and three were at low RoB. There was insufficient evidence to determine if there is a difference in the alignment rate between Multistrand stainless steel (MSS) and superelastic nickel-titanium (SNT) arch wires (mean difference (MD) -7.5 mm per month, 95% confidence interval (CI) -26.27 to 11.27; one study), between MSS and thermoplastic NiTi (TNT) arch wires, between conventional Niti (CNT) and TNT arch wires, between CNT and TNT arch wires and between SNT and TNT arch wires. In regards to pain level only two comparisons were assessed (MSS vs. SNT and SNT vs. TNT). The first one did not show meaningful differences while in the second insufficient evidence was identified. Conclusions In general terms there is insufficient evidence that any particular material is clinically superior to any other in regards to alignment rate, pain or root resorption.

Initial arch wires used in orthodontic treatment with fixed appliances.

Initial arch wires used in orthodontic treatment with fixed appliances.

Relationship between initial archwire materials and pain at the initial stage of orthodontic treatment: a systematic review and network Meta-analysis

This review aims to assess the relationship between initial archwire materials and pain at the initial stage of orthodontic treatment. On October 1, 2017, seven databases were searched electronically for studies oninitial archwire materials and pain at the initial stage of orthodontic treatment. Quality assessment was performed with bias risk assessment tools suggested by Cochrane's handbook. Data extraction of included studies was also carried out. Network Meta- analysis was conducted using R 3.4.2 (with JAGS 4.3.0), GeMTC 0.14.3, and STATA 11.0. Five studies with 330 participants were included, comparing four different materials: multi-stranded stainless steel, conventional nickel-titanium, super-elastic nickel-titanium, and thermal heat-activated nickel-titanium. Two studies were at low risk of bias, one was at high risk of bias, and the remaining two were at unclear risk of bias. Network Meta-analysis results showed no statistical differences of pain among the four initial archwire materials at day 1 and day 7. However, the most painless material was most likely to be thermal heat-activated nickel-titanium on rank probability. On statistical probability, thermal heat-activated nickel-titanium initial arch wires is most likely to cause the least pain at the initial stage of orthodontic treatment, compared with other materials.

An evaluation and comparison of myeloperoxidase enzymatic activity during initial orthodontic alignment: an in vivo study.

Tooth movement during orthodontic treatment is possible because of mechanical force-induced inflammation and remodelling in the periodontal ligament. Variation in the inflammatory response might be anticipated with initial aligning archwires of different composition. Myloperoxidase (MPO) is an enzyme found in neutrophil granules that represents an important marker of inflammation. The aim of this study was to measure MPO enzyme activity during initial alignment with orthodontic arch wires of different alloy types. MPO activity was determined in gingival crevicular fluid (GCF) from a sample of 60 patients divided into three groups during initial orthodontic alignment with three types of arch wire (0.016-inch superelastic (SE) NiTi; 0.016-inch heat-activated (HANT) NiTi and 0.00175-inch multistranded stainless steel). MPO activity was measured at baseline, 2 hours, 7 and 14 days after appliance activation. MPO activity was significantly increased in GCF at 2 hours (P < 0.01), 7 and 14 days in all groups compared to baseline. Enzymatic activity was highest in the SE NiTi group followed by HANT and multistranded stainless steel groups but with no significant difference between SE NiTi and HANT groups. SE and HANT NiTi arch wires produce an increased inflammatory response based upon MPO activity during initial levelling and alignment compared to multistranded stainless steel.

A Systematic review on aligning efficiency of superelastic NITI: in comparison with conventional NITI and multistranded stainless steel archwires

Background: The initial leveling and aligning phase of orthodontic treatment involve the use of nickel titanium wires. The nickel titanium wires exhibit unique properties like shape memory and superelasticity. In the beginning, conventional nitinol wires were used, which lacked the superelastic property. Nowadays, superelastic nickel titanium wires are being used commonly. This systematic review aims to evaluate the efficiency of Superelastic NITi in the initial alignment of orthodontic treatment in comparison with conventional NiTi and multistranded stainless steel archwires by measuring the amount of decrowding and the time taken for decrowding.Method: A systematic literature search was performed on Pubmed, Cochrane, Google scholar &amp; Lilacs.Result: Thirty four studies were identified by the search and ten studies satisfied the inclusion criteria and one study was excluded after abstract reading. Finally nine articles were included for quality assessment.Conclusion: This systematic review concluded that there was no significant differences in the aligning efficiency of superelastic NiTi in comparison with conventional NiTi and multistranded stainless steel wires.Â

Forces in initial archwires during leveling and aligning: An in-vitro study.

Aim:This in-vitro study measured the force deflection behavior of selected initial alignment archwires by conducting three-point bending tests under controlled tests. The study tested three wire designs, namely, co-axial multistranded stainless steel wires, nickel–titanium, and copper–nickel–titanium archwires.Materials and Methods:The archwires were ligated to a specially designed metal jig, simulating the arch. A testing machine (Instron) recorded activation and deactivation forces of different deflections at 37°C. Forces on activation and deactivation were compared by one-way analysis of variance (ANOVA).Results:Significant differences (P < 0.05) in activation and deactivation forces were observed among the tested wires. The co-axial multistranded wire had the lowest mean activation and deactivation forces, whereas conventional nickel–titanium wires had more mean activation and deactivation forces at different deflections.Conclusion:The activation and deactivation forces were higher for nickel–titanium followed by copper–nickel titanium and co-axial wires. The amount of percentage force loss was more for co-axial wire, indicating that these wires are not ideal for initial leveling and aligning.

In vivo orthodontic retainer survival - a review.

BackgroundRelapse following orthodontic treatment is a constant concern of orthodontists. Fixed retention is preferred especially for the lower arch by most orthodontists.ObjectivesThis review focuses on in vivo studies. The main objective is to determine the survival rates of different types of retainer: glass-fiber reinforced composite resin, polyethylene or multistrand stainless steel wire bonded to each tooth from canine to canine in the mandibular arch. A second objective is to assess which of these types is less likely to cause additional problems and the third objective is to evaluate the factors that may influence retainer survival.Results and conclusionsThere were 8 studies identified that matched the objectives stated. Current in vivo studies on survival rate take little notice of the role of the material used for bonding of the fixed retainer. It is not possible to draw a conclusion on reliability of new types of retainers glass fiber reinforced composite resin or polyethylene compared to multistrand stainless steel wire. The multistrand wire remains the gold standard for fixed retention.Although it is a logical outcome that retainer survival is dependent on the application technique, there seems to be no research outcome proving that operator experience, moisture control are essential, nor does patient age or sex have statistically proven effects on survival rates.Adequate studies that involve such aspects should be performed.

Root resorption after leveling with super-elastic and conventional steel arch wires: a prospective study

BackgroundThe aim of this prospective study was to compare root resorption after the leveling phase of treatment, performed by either super-elastic or conventional multi-stranded stainless steel arch wires.MethodsFrom a total of 156 future orthodontic patients in a private clinic, 82 were included in the study after excluding those who earlier had orthodontic or endodontic treatment or signs of resorption. Patients were equally arbitrary allocated into two groups, where leveling was performed either with super-elastic heat-activated or conventional multi-stranded stainless steel arch wires. Root length loss was calculated using pre-treatment and post-leveling periapical radiographs.ResultsThe use of super-elastic arch wires did not significantly increase the severity of root resorption, except for tooth 31, while it reduced leveling time compared to conventional stainless steel wires. Crossbite of maxillary lateral incisors seemed to be a risk factor for resorption.ConclusionIncisor root resorption after leveling did not differ significantly between patients treated with super-elastic and conventional stainless steel arch wires, except for a mandibular incisor.Electronic supplementary materialThe online version of this article (doi:10.1186/s40510-014-0035-z) contains supplementary material, which is available to authorized users.

Clinical evaluation of bond failures and survival between mandibular canine-to-canine retainers made of flexible spiral wire and fiber-reinforced composite.

Objectives: The purpose of this longitudinal prospective randomized study was to evaluate the clinical reliability of two different types of postorthodontic treatment retainers: a silanised-treated glass fibers-reinforced resin composite (FRC) and a directly bonded multistranded stainless steel wire. The hypothesis of the study was to assess if significant differences are present between failure rates of the two retainers. Study Design: This prospective study was based on an assessment of 87 patients (35 men and 52 women),with an average age of 24 years who required a lower arch fixed retainer after orthodontic treatment. Patients were divided in two groups. Assignment was carried out with random tables. A follow-up examination was carried out once a month. The number, cause, and date of single bond adhesive failures were recorded for both retainers over 12 months. Teeth that were rebonded after failure were not included in the success analysis. Statistical analysis was performed by means of a Fisher’s exact test, Kaplan-Meier survival estimates, and log rank test. Results: Bond failure rate was significantly higher (P=0.0392) for multistranded metallic wire than for FRC. Conclusions: Glass fiber-reinforced resin composite retainers and multistranded metallic wires showed no significant difference in single bond failure rates over a one-year follow up. Key words:Fiber reinforced composite, fixed retention, multistranded wire, orthodontics, retainer, splint.

A randomized clinical trial investigating pain associated with superelastic nickel–titanium and multistranded stainless steel archwires during the initial leveling and aligning phase of orthodontic treatment

Objective:To investigate and compare the effects of superelastic nickel–titanium and multistranded stainless steel archwires on pain during the initial phase of orthodontic treatment.Design:A double-blind two-arm parallel design stratified randomized clinical trial.Setting:A single centre in India between December 2010 and June 2012. A total of 96 participants (48 male and 48 females; 14.1±2.1 years old) were randomized (stratified on age, sex and initial crowding) to superelastic nickel–titanium or multistranded stainless steel archwire groups using a computer-generated allocation sequence.Methods:We compared 0.016-inch superelastic nickel–titanium and 0.0175-inch multistranded stainless steel wires in 0.022-inch slot (Roth prescription) preadjusted edgewise appliances. The follow-up period was 14 days. Outcome was assessed with a visual analogue scale at baseline and 32 pre-specified follow-up points. Data was analyzed using mixed-effects model analysis.Results:One participant was lost to follow up and 10 were excluded from the analysis due to bond failure or incomplete questionnaire answers. Ultimately, 85 participants (42 males and 43 females; 14.1±2.0 years old) were analysed for the final results. No statistically significant difference was found for overall pain [F value = 2.65, degrees of freedom (df) = 92.6; P = 0.1071]. However, compared to multistranded stainless steel wires, pain in subjects with superelastic nickel–titanium archwires was significantly greater at 12 h (t = 2.34; P = 0.0193), as well as at day 1 in the morning (t = 2.21, P = 0.0273), afternoon (t = 2.11, P = 0.0346) and at bedtime (t = 2.03, P = 0.042).Conclusion:For overall pain, there was no statistically significant difference between the two wires. However, subjects with superelastic nickel–titanium archwires had a significantly higher pain at peak level.