A clinical comparison of three aligning archwires in terms of alignment efficiency: A prospective clinical trial

Objectives:To clinically evaluate the effectiveness of three orthodontic aligning archwires in relation to tooth alignment speed during the initial alignment stage of treatment.Materials and Methods:A consecutive sample of 74 patients requiring lower only or upper and lower fixed orthodontic appliances were randomly allocated into three different archwires (0.014-inch superelastic nickel-titanium [NiTi], 0.014-inch thermoelastic NiTi, or 0.014-inch conventional NiTi). Good quality impressions were taken of the lower arch before archwire placement (T0) and at designated serial stages of alignment (every 2 weeks: T2, T4, T6, …, T16). The change in tooth alignment was measured in millimeters from the resultant casts using Little''s irregularity index. Demographic and clinical differences among the three groups were compared with the chi-square or analysis of variance (ANOVA) test. The difference in the change of lower anterior tooth alignment over time among the three groups was explored with a Split Plot ANOVA (SPANOVA, or within- and between-groups ANOVA). The Kruskal-Wallis nonparametric test was used when data were not normally distributed.Results:The SPANOVA and Wilks Lambda Multivariate test confirmed that the wire type had no influence on the rate of change in alignment (P  =  .98).Conclusion:The three forms of NiTi wires were similar in terms of their alignment efficiency during the initial aligning stage of orthodontic fixed appliance therapy.     

Comparison of changes in irregularity and transverse width with nickel-titanium and niobium-titanium-tantalum-zirconium archwires during initial orthodontic alignment in adolescents: A double-blind randomized clinical trial

Objectives:The purpose of this prospective, double-blind, randomized clinical trial was to compare the clinical efficiency of nickel-titanium (NiTi) and niobium-titanium-tantalum-zirconium (TiNbTaZr) archwires during initial orthodontic alignment.Materials and Methods:All subjects (ages between 12 and 20 years) underwent nonextraction treatment using 0.022-inch brackets. All patients were randomized into two groups for initial alignment with 0.016-inch NiTi archwires (n = 14), or with 0.016-inch TiNbTaZr archwires (n = 14). Digital scans were taken during the course of treatment and were used to compare the improvement in Little''s Irregularity Index and the changes in intercanine and intermolar widths.Results:There was approximately a 27% reduction in crowding during the first month with the use of 0.016-inch TiNbTaZr (Gummetal) wire, and an additional 25% decrease in crowding was observed during the next month. There was no significant difference between the two treatment groups in the decrease in irregularity over time (P = .29). There was no significant difference between the two groups in the changes in intercanine and intermolar width (P = .80).Conclusions:It can be concluded that Gummetal wires and conventional NiTi wires possess a similar ability to align teeth, and Gummetal wires have additional advantages over conventional NiTi, such as formability and use in patients with nickel allergy.     

The effect of temperature on the mechanical behavior of nickel-titanium orthodontic initial archwires

Objectives:To investigate and compare the characteristics of commonly used types of traditional and heat-activated initial archwires at different temperatures by plotting their load/deflection graphs and quantifying three parameters describing the discharge plateau phase.Materials and Methods:Forty-eight archwires of cross-sectional diameters ranging from 0.010 inches to 0.016 inches were obtained from seven different manufacturers. A modified three-point wire-bending test was performed on three analogous samples of each type of archwire at 55°C and 5°C, simulating an inserted archwire that is subjected to cold or hot drinks during a meal. For each resulting load/deflection curve the plateau section was isolated and the mean value of each parameter for each type of wire was obtained.Results:Permanent strain was exhibited by all wires tested at 55°C. Statistically significant differences were found between almost all wires for the three considered parameters when tested at 55°C and 5°C. Loads were greater at 55°C than at 5°C. Differences were also found between traditional and heat-activated archwires, the latter of which generated longer plateaus at 55°C, shorter plateaus at 5°C, and lighter mean forces at both temperatures. The increase in average force seen with increasing diameter tended to be rather stable at both temperatures.Conclusions:All nickel-titanium wires tested showed a significant change related to temperature in terms of behavior and force for both traditional and heat-activated wires. Stress under high temperatures can induce permanent strain, whereas the residual strain detected at low temperatures can be recovered from as temperature increases.     

Tooth and bone changes after initial anterior dental alignment using preformed vs customized nickel titanium archwires in adults: A randomized clinical trial

Objectives:To compare tooth movement achieved, time required for alignment, root resorption, and alveolar bone thickness changes during initial dental alignment between groups treated with 0.012-inch preformed heat-activated or customized nickel titanium (NiTi) archwires.Materials and Methods:Thirty-two subjects (mean age 19.8 ± 1.7 years) with severe crowding of maxillary anterior teeth had premolar extractions and were randomly allocated into control and experimental groups receiving preformed heat-activated and customized NiTi archwires, respectively. Limited field of view cone-beam computed tomographies were taken initially (T₀) and three months after final alignment (T_F) to evaluate bone changes. Digital model analysis assessed tooth movement at monthly intervals. Time to achieve alignment was assessed in months. Wilcoxon signed-rank tests and Mann–Whitney U-tests were used to compare changes within and between groups, as appropriate.Results:Central incisor tooth movement was significantly different (all P ≤ .003) between groups at all time points. T_F-T₀ showed labial movement (0.75 ± 1.42 mm) in the control group and palatal movement (−0.96 ± 0.41 mm) in the experimental group. The experimental compared to control group showed significantly more canine distal movement (0.60 ± 0.28 mm; P ≤ .049), less labial bone thickness changes (P ≤ .004), less root resorption of the central and lateral incisors (P ≤ .007), and a longer time to achieve alignment (P = .01).Conclusions:The experimental group exhibited palatal movement of the central incisors, more canine distal movement with less bone thickness changes, and less root resorption but took more time to achieve alignment than the control group.     

A systematic review of clinical trials of aligning archwires

Abstract

Objectives: This review aimed to identify the evidence for the efficacy of archwires used in the alignment stage of orthodontic treatment by undertaking a systematic review of the literature.

Data Sources: MEDLINE, the Cochrane Central Register of Controlled trials (CENTRAL), EMBASE, and the meta Register of Controlled Trials were searched up to July 2008. Reference lists of identified articles and relevant review articles were checked for further possible studies.

Review Methods: Controlled clinical trials and randomised clinical trials that compared aligning archwires and reported objective measures of alignment were selected for inclusion. Validity and quality assessment were undertaken to identify studies with a low risk of bias. Details of the study methodology and the reported results were then abstracted.

Results: 100 studies were identified by the searches and 7 of these were identified as meeting the selection criteria. Four studies were deemed, after quality assessment, to have a low risk of bias and data was extracted from these. No two studies shared a common methodology or common reporting of outcome. Meta-analysis was therefore not possible.

Conclusions: There is insufficient data in these studies to make clear recommendations regarding the most effective archwire for alignment. Recommendations on future study design have been made.     

Streptococcus mutans adhesion on nickel titanium (NiTi) and copper-NiTi archwires: A comparative prospective clinical study

Objectives:To compare the adhesion of Streptococcus mutans to nickel titanium (NiTi) and copper-NiTi (Cu-NiTi) archwires and to correlate the adhesion to surface characteristics (surface free energy and surface roughness) of these wires.Materials and Methods:A total of 16 patients undergoing orthodontic treatment with preadjusted edgewise appliances were included in the study. 0.016” and 0.016” × 0.022” NiTi and Cu-NiTi archwires in as-received condition and after 4 weeks of intraoral use were studied for S mutans adhesion using real-time polymerase chain reaction. Surface roughness and surface free energy were studied by three-dimensional surface profilometry and dynamic contact angle analysis, respectively.Results:S mutans adhesion was more in Cu-NiTi archwires. These wires exhibited rougher surface and higher surface free energy when compared to NiTi archwires.Conclusions:S mutans adhesion, surface roughness, and surface free energy were greater in Cu-NiTi than NiTi archwires. Surface roughness and surface free energy increased after 4 weeks of intraoral exposure for all of the archwires studied. A predominantly negative correlation was seen between the cycle threshold value of adherent bacteria and surface characteristics.     

Alignment efficiency and discomfort of three orthodontic archwire sequences: a randomized clinical trial

Abstract

Aim: To compare the efficiency of orthodontic archwire sequences produced by three manufacturers.

Design: Prospective, randomized clinical trial with three parallel groups.

Setting: Private orthodontic practice in Caloundra, QLD, Australia

Subjects and methods: One hundred and thirty‐two consecutive patients were randomized to one of three archwire sequence groups: (i) 3M Unitek, 0·014?inch Nitinol, 0·017?inch×0·017?inch heat activated Ni–Ti; (ii) GAC international, 0·014?inch Sentalloy, 0·016×0·022?inch Bioforce; and (iii) Ormco corporation, 0·014?inch Damon Copper Ni–Ti, 0·014×0·025?inch Damon Copper Ni–Ti. All patients received 0·018×0·025?inch slot Victory Series^TM brackets.

Outcome measures: Mandibular impressions were taken before the insertion of each archwire. Patients completed discomfort surveys according to a seven‐point Likert Scale at 4?h, 24?h, 3?days and 7?days after the insertion of each archwire. Efficiency was measured by time required to reach the working archwire, mandibular anterior alignment and level of discomfort.

Results: No significant differences were found in the reduction of irregularity between the archwire sequences at any time‐point (T1: P?=?0·12; T2: P?=?0·06; T3: P?=?0·21) or in the time to reach the working archwire (P?=?0·28). No significant differences were found in the overall discomfort scores between the archwire sequences (4?h: P?=?0·30; 24?h: P?=?0·18; 3?days: P?=?0·53; 7?days: P?=?0·47). When the time‐points were analysed individually, the 3M Unitek archwire sequence induced significantly less discomfort than GAC and Ormco archwires 24?h after the insertion of the third archwire (P?=?0·02). This could possibly be attributed to the progression in archwire material and archform.

Conclusions: The archwire sequences were similar in alignment efficiency and overall discomfort. Progression in archwire dimension and archform may contribute to discomfort levels. This study provides clinical justification for three common archwire sequences in 0·018×0·025?inch slot brackets.     

A comparative study between the effect of reverse curve of Spee archwires and anterior bite turbos in the treatment of deep overbite cases:: A randomized clinical trial

ObjectivesTo compare deep overbite treatment using 0.016 × 0.022 nickel-titanium lower reverse curve of Spee archwire (LRCA) or metal anterior bite turbos (ABTs).Materials and Methods48 patients with deep overbite malocclusion were randomly allocated into two groups. Group I (age = 18.4 ± 2.8 years, overbite = 5.8 ± 0.6 mm) was treated with LRCA, while Group II (age = 18.2 ± 3.1 years, overbite = 5.2 ± 0.4 mm) was treated with ABTs bonded to the palatal surface of the upper central incisors. Two cephalograms were taken for each patient, at post-alignment stage (T1) and post-leveling stage (T2). The primary outcomes were the anteroposterior and vertical changes of the lower teeth. The secondary outcomes were the effect on upper incisor inclination and the vertical linear changes of upper teeth, to assess the sagittal and vertical skeletal changes, and to compare the duration of overbite correction.Results42 of the 48 patients recruited completed the study (21 in each group). At T2, the lower incisors proclined more in Group I (P ≤ .001). Both lower second molars (P ≤ .001) and lower first molars (P = .001) tipped more distally, while the lower first premolar tipped more mesially, in Group I (P < .05). All cusps of both lower molars showed more extrusion in Group II (P < .05) except for the mesial cusp of lower second molars (P = .095). The duration of overbite correction was shorter using the ABTs by 1.7 months (4.85 ± 1.56 and 3.15 ± 0.93 months for Group I and Group II, respectively).ConclusionsLRCA causes lower incisor proclination with distal tipping of lower molars, while ABTs result in lower posterior tooth extrusion.     

A clinical trial of Damon 2 vs conventional twin brackets during initial alignment

The objective of this study was to compare the effectiveness and comfort of Damon 2 brackets and conventional twin brackets during initial alignment. Sixty consecutive patients participated in a split mouth design. One side of the lower arch was bonded with the Damon 2 bracket and the other with a conventional twin bracket. The sides were alternated with each consecutive patient. The irregularity index (II) was measured for each half of the arch at baseline, at 10 weeks at the first archwire change, and at another 10 weeks at the second archwire change. Any difference in discomfort was assessed within the first few days of archwire placement and again at the first archwire change. Comfort on the lips, preferred look, and bracket failure rates were also recorded. The twin bracket was more uncomfortable with the initial archwire (P = .04). However, at 10 weeks, substantially more patients reported discomfort with the Damon 2 bracket when engaging the archwire (P = .004). At both archwire changes at 10 and 20 weeks (P = .001), the conventional bracket had achieved a lower II than the Damon 2 bracket by 0.2 mm, which is not clinically significant. Patients preferred the look of the twin bracket over the Damon 2 (P < .0005) and more Damon 2 brackets debonded during the study (P < .0005). The Damon 2 bracket was no better during initial alignment than a conventional bracket. Initially, the Damon 2 bracket was less painful, but it was substantially more painful when placing the second archwire and had a higher bracket failure rate.     

Pain control in orthodontics using a micropulse vibration device: A randomized clinical trial

Objective:To investigate the relationship between a micropulse vibration device and pain perception during orthodontic treatment.Materials and Methods:This study was a parallel group, randomized clinical trial. A total of 58 patients meeting eligibility criteria were assigned using block allocation to one of two groups: an experimental group using the vibration device or a control group (n  =  29 for each group). Patients used the device for 20 minutes daily. Patients rated pain intensity on a visual analog scale at appropriate intervals during the weeks after the separator or archwire appointment. Data were analyzed using repeated measures analysis of variance at α  =  .05.Results:During the 4-month test period, significant differences between the micropulse vibration device group and the control group for overall pain (P  =  .002) and biting pain (P  =  .003) were identified. The authors observed that perceived pain was highest at the beginning of the month, following archwire adjustment.Conclusion:The micropulse vibration device significantly lowered the pain scores for overall pain and biting pain during the 4-month study period.     

Pain experience in adults undergoing treatment: A longitudinal evaluation

Objectives:To quantify the intensity and duration of pain experience in adults over the initial three visits of fixed appliance–based orthodontic treatment. A secondary objective was to assess the relationship between pain experience and analgesic use, dental irregularity, gender, and age.Materials and Methods:A prospective longitudinal study design was adopted. Fifty-eight adults undergoing fixed appliance treatment in five orthodontic practices recorded pain experience at four time points (4 hours, 24 hours, 3 days, and 7 days) following the initial bond-up appointment (T0) and first (T1) and second (T2) routine follow-up adjustment appointments using a visual analogue scale. In addition, subjects recorded the dosage and frequency of analgesic use.Results:A slightly greater proportion of women (57%) were recruited, with a mean sample age of 34.69 (SD 12.11) years. Peak pain was experienced between 24 hours and 3 days following appliance placement (T0) and subsequent adjustments (T1 and T2). The highest mean pain score arose at T0 followed by T2 and T1 adjustments, with the difference between pain levels at these appointment intervals being statistically significant (P < .001). The use of analgesics following each appointment mirrored pain experience, with pain score, appointment, and time point all being significant predictors of analgesic consumption. The level of dental irregularity, gender, or age did not predict pain levels reported.Conclusions:Adults undergoing fixed orthodontic therapy should be advised that they are most likely to experience increased levels of pain for 1 to 3 days following placement of their appliance and subsequent adjustment visits.     

Perceived pain during rapid maxillary expansion in children with different expanders:: A prospective study

ObjectivesTo evaluate and compare the intensity of pain caused by rapid maxillary expansion (RME) with two expanders: Hyrax and Haas type, in growing patients.Materials and MethodsThirty-nine patients (23 girls and 16 boys) with an average age of 9.3 years (SD = 1.39 years) were randomized into two groups and treated with Hyrax- and Haas-type expanders. In both groups, initial activation of the expander screw was one full turn on the first day followed by 2/4 of a turn two times a day (morning and night) for 7 days. Inclusion criteria were patients presenting with a posterior crossbite or maxillary atresia between 7 and 12 years old. To evaluate the intensity of pain during the active phase of the treatment, a combination of the Numerical Rating Scale and Wong-Baker Faces Pain Scale was used. Mann-Whitney test was used to compare the two treatment groups.ResultsThere was significant inverse correlation between days following insertion and pain. During the expansion period, 100% of the children reported some pain. Hyrax expander subjects reported greater pain than those treated with the Haas-type expander only on the first day. The level of pain remained greater in girls throughout treatment.ConclusionsPain was reported regardless of the type of expander and was higher in the Hyrax group only on the first day of activation.     

Discomfort associated with Invisalign and traditional brackets: A randomized,prospective trial

Objective:To evaluate differences in discomfort levels between patients treated with aligners and traditional fixed orthodontic appliances.Materials and Methods:This blinded, prospective, randomized equivalence two-arm parallel trial allocated 41 adult Class I nonextraction patients to either traditional fixed appliance (6 males and 12 females) or aligner (11 males and 12 females) treatment. Patients completed daily discomfort diaries following their initial treatment appointment, after 1 month and after 2 months. They recorded their levels of discomfort at rest, while chewing, and while biting, as well as their analgesic consumption and sleep disturbances.Results:Both treatment modalities demonstrated similar levels of initial discomfort. There were no significant sex differences. Patients in the traditional fixed appliances group reported significantly (P < .05) greater discomfort than patients in the aligner group during the first week of active treatment. There was significantly more discomfort while chewing than when at rest. Traditional patients also reported significantly more discomfort than aligner patients after the first and second monthly adjustment appointments. Discomfort after the subsequent adjustments was consistently lower than after the initial bonding or aligner delivery appointments. A higher percentage of patients in the fixed-appliance group reported taking analgesics during the first week for dental pain, but only the difference on day 2 was statistically significant.Conclusions:Patients treated with traditional fixed appliances reported greater discomfort and consumed more analgesics than patients treated with aligners. This trial was not registered.     

Orthodontic debonding and tooth sensitivity of anterior and posterior teeth:: A prospective clinical trial

ObjectivesTo assess whether orthodontic debonding and onset of tooth sensitivity were related and if anterior and posterior teeth showed different sensitivity.Materials and Methods40 patients were divided into a trial group (group 1, at the end of the multibracket treatment) and a control group (group 2, not under treatment). After the application of compressed air and cold water to mandibular incisors and first molars, participants were asked to report the pain felt for each tooth using a 100-mm visual analogue scale. In group 1, assessment was performed just before debonding (T₀), immediately after completion of debonding (T₁) and 7 days after (T₂). In group 2, values were assessed at the beginning of a follow-up visit (T₀), at the end of the same visit (T₁) and 7 days after (T₂).ResultsConsidering overall teeth, statistical analyses showed significantly higher values in the trial group at T₁ after both stimuli, especially after cold water, besides a significant difference between T₀ and T₂ values in the same group. Anterior teeth showed significantly higher VAS scores than posterior after the two thermal stimuli, except after air stimulation in group 1 at T₂ and in group 2.ConclusionsOrthodontic debonding leads to sensitivity to thermal stimuli especially in the anterior teeth, however pain level is restored within 7 days.     

Evaluation of self-perceived pain and jaw function impairment in children undergoing slow and rapid maxillary expansion:: A prospective clinical trial

ObjectivesTo evaluate and compare perceived pain and jaw function impairment during the first 4 weeks with slow maxillary expansion (SME) using quadhelix and rapid maxillary expansion (RME) using conventional banded hyrax.Materials and MethodsSixty patients aged 10.2 to 15 years were enrolled and consecutively recruited to either the quadhelix group (QG) or hyrax group (HG). A questionnaire was used to evaluate pain, jaw function impairment, and analgesic consumption in the first 7 days, at 2 weeks, and at 4 weeks.ResultsFifty-five patients (43 girls and 12 boys) completed the questionnaire at all time points (27 in the QG and 28 in the HG). Except at 4 hours, there were no significant differences between the groups regarding pain from teeth, tongue, and palate. Patients started to adapt after day 3. Patients in the HG group reported significantly higher scores for difficulty in swallowing (moderate to severe) during the first 6 days. In both groups, minimal effects were found on speech and the majority of patients did not experience difficulty in yawning or laughing. There was no significant difference in analgesic consumption between the groups. No correlations were found between age, gender, or malocclusion type and any of the investigated outcomes.ConclusionsQuadhelix for SME and conventional banded hyrax for RME were well tolerated by patients after 1 week. The decision to use either appliance could be based on factors not related to patient experiences.     

A prospective randomized split-mouth study on pain experience during chairside archwire manipulation in self-ligating and conventional brackets

Objective:To investigate patient discomfort during archwire engagement and disengagement in patients treated with self-ligating and conventional brackets using a split-mouth design.Materials and Methods:Eighteen consecutive patients (15 female, 3 male; age: 22.2 ± 6.4 years) who requested treatment with fixed orthodontic appliances were randomly assigned for bonding with SmartClip self-ligating brackets on one side of the dentition and conventional standard edgewise brackets on the other. During the course of treatment, patients rated the discomfort experienced during every archwire engagement and disengagement using a numeric rating scale. Results were evaluated for round and rectangular nickel titanium and rectangular stainless steel, titanium molybdenum, and Elgiloy archwires. Patients also rated their overall experience retrospectively for both bracket systems.Results:Regardless of archwire type, disengagement was rated as being significantly more painful on the SmartClip side (P  =  .027). For rigid, rectangular archwires, engagement and disengagement were rated as being significantly more painful on the SmartClip side (P  =  .031; P  =  .004). Retrospective ratings favored conventional brackets beyond ratings recorded during treatment.Conclusion:Engagement and disengagement of rigid rectangular archwires caused more pain with SmartClip self-ligating brackets than with conventional ones. Careful archwire manipulation and patience during full alignment are essential for limiting chairside pain. Low pain levels will help ensure treatment satisfaction and compliance.