Esthetic Brackets Research Articles

Evaluation and Comparison of the Color Stability of Various Esthetic Brackets, When Exposed to Various Food Dyes: An in vitro Study

Evaluation and Comparison of the Color Stability of Various Esthetic Brackets, When Exposed to Various Food Dyes: An in vitro Study

Invisible orthodontics part 3: aesthetic orthodontic brackets

In this, the third part of the series, aesthetic orthodontic treatment will be considered. The previous two articles have looked at invisible orthodontics with Invisalign and lingual brackets. This article will discuss the properties and use of aesthetic brackets, along with examples of orthodontic treatment cases using the aesthetic brackets. Increasing demand for aesthetics during orthodontic treatment has resulted in a significant increase in the use of aesthetic brackets. Clinicians need to be aware of the benefits and drawbacks of aesthetic brackets.

Evaluation of physical properties of esthetic brackets after clinical use: Study in situ

AimThe aim of this study was to investigate the surface morphology, dimensional stability, and frictional behavior of ceramic brackets with metal-inserted slots after different intervals of intraoral use. MethodsEighty-eight brackets were evaluated. The sample was divided into four groups (n = 22 per group): group C (control, as received from the manufacturer) and groups T12, T24, and T36 (brackets recovered after 12, 24, and 36 months of treatment, respectively). Surface morphology was analyzed with optical and scanning electron microscopy. Dimensional stability was verified with a measuring microscope, and sliding resistance on 0.019 × 0.025-in stainless steel wires was evaluated using a universal testing machine. ResultsSigns of corrosion and wear occurred gradually from the 12th to the 36th month, being more significant at the metal slot base and at the porcelain/metal junction. The depth of the slot and the internal height between the tie-wings increased after clinical use, showing a significant difference at 36 months (P < 0.05). There was a progressive increase in the coefficient of friction versus time of clinical use and a maximum increase of 22% after 36 months (P < 0.05). ConclusionsCeramic brackets with metal-inserted slots had significant changes in physical properties during clinical use. The dimensional changes encountered were small and appeared clinically nonsignificant. However, the progressive increase in the coefficient of friction must be taken into consideration because it may compromise the clinical performance of the appliance.

Effect of applied moment on resistance to sliding among esthetic self-ligating brackets

To determine the effect of mode of ligation and bracket material on resistance to sliding (RS) by comparing various esthetic brackets of conventionally ligated and self-ligating (SL) designs under an increasing applied moment in the second-order dimension. Eight different commercially available esthetic brackets of SL and conventional elastomeric-ligated (CL) designs were mounted on a testing apparatus to simulate canine retraction using sliding mechanics and the application of a moment on 0.019″×0.025″ stainless steel archwire. The samples examined were the CL brackets Clarity™, Inspire Ice™, SpiritMB™, and Mystique™, and the SL brackets ClaritySL™, In-OvationC™, In-OvationR™, and Smartclip™. The RS at calculated moments of 2000 g-mm and 4000 g-mm was determined and compared between the various brackets. Descriptive measures and one-way analysis of variance were used to calculate means and statistical differences among the bracket types. The CL monocrystalline bracket displayed significantly greater (P < .05) RS than all other brackets tested. Among the other brackets, the range of RS values was 145.8-191.7 g and 291.9-389.2 g at moments of 2000 g-mm and 4000 g-mm, respectfully, though these differences were not significant (P < .05). All brackets tested displayed greater levels of RS (P < .05) at 4000 g-mm than at 2000 g-mm. With the exception of the CL monocrystalline bracket, all brackets displayed comparable amounts of RS regardless of mode of ligation or bracket slot material.

Imagistic Evaluation of the Orthodontics Interfaces

In orthodontics, the scientific interest regarding adhesion is focused on optimizing adherents: metallic or aesthetic bracket base conditioning, creating aesthetic brackets with improved mechanical properties, enamel conditioning and artificial surface conditioning (aesthetic veneers and crowns). In order to investigate the interfaces between adherents there are several invasive (destructive) methods such as tensile bond strength tests, shear bond strength tests and microleakage tests.

Colour stability of aesthetic brackets: ceramic and plastic

Abstract Background: The colour stability of aesthetic brackets may differ according to their composition, morphology and surface property, which may consequently influence their aesthetic performance. Aims: To assess the colour stability of aesthetic brackets (ceramic and plastic) after simulating aging and staining. Methods: Twelve commercially manufactured ceramic brackets and four different plastic brackets were assessed. To determine possible colour change (ΔE*ab) and the value of the NBS (National Bureau of Standards) unit system, spectrophotometric colour measurements for CIE L*, a* and b* were taken before and after the brackets were aged and stained. Statistical analysis was undertaken using a one-way ANOVA analysis of variance and a Tukey multiple comparison test (α = 0.05). Results: The colour change between the various (ceramic and plastic) materials was not significant (p &gt; 0.05), but still varied significantly (p &lt; 0.001) between the brackets of the same composition or crystalline structure and among commercial brands. Conclusion: Colour stability cannot be confirmed simply by knowing the type of material and crystalline composition or structure. (Aust Orthod J 2013; 29: 13-20)

Invisible orthodontics part 1: invisalign

This paper discusses the invisible orthodontic treatment modalities of Invisalign aligners, lingual appliances and aesthetic brackets. The first part of this three-part series will discuss Invisalign aligner treatment. The second part will discuss lingual appliance treatment and the third part will focus on aesthetic brackets. The benefits and drawbacks of Invisalign treatment are considered in detail, including examples of treated cases and a review of the literature to date. Patients are increasingly requesting more aesthetic forms of orthodontic treatment. Clinicians need to be aware of the indications and limitations of such invisible therapies so that they can fully inform their patients.

Colonization of Streptococcus mutans on esthetic brackets: Self-ligating vs conventional

Self-ligating orthodontic brackets rely on clips, rather than ligatures, to hold the archwire in place. It is unknown whether replacing ligatures with clips affects the adherence of Streptococcus mutans. The aim of this research was to evaluate whether self-ligating brackets have an advantage over conventional brackets as determined by the adherence of S mutans. The sample consisted of 50 esthetic brackets, divided into 3 experimental groups and 2 control groups of 10 brackets each. Two experimental groups were active self-ligating brackets (QuicKlear; Forestadent, Pforzheim, Germany; and In-Ovation C; Dentsply GAC, Bohemia, NY); the other was a passive self-ligating bracket (Damon 3; Ormco, Glendora, Calif). The 2 control groups were conventional brackets (Mystique; Dentsply GAC; and Clarity; 3M Unitek, Monrovia, Calif). The brackets were randomly bonded to the canines, first and second premolars, and first and second molars in the mandibular left hemiarch of 10 male participants. Biofilm was collected from the tooth surfaces before bonding and from the brackets on day 21 and placed in Petri dishes containing Mitis salivarius agar. The brackets were removed on day 28 and examined by using scanning electron microscopy. Statistical analysis, analysis of variance, and the Tukey correction with a P value of 0.05 were used. The greatest numbers of colonies were found in an active self-ligating bracket group (In-Ovation C), and the fewest colonies were in a conventional bracket group (Clarity). The largest colonies formed on active self-ligating brackets. In the slot, the greatest formation was in a control group (Mystique). Self-ligating esthetic brackets do not promote greater or lesser S mutans colonization when compared with conventional brackets. Differences were found to be related to the material composition of the bracket.

Evaluation of the friction force generated by monocristalyne and policristalyne ceramic brackets in sliding mechanics

To evaluate and compare "in vitro" the maximum friction force generated by three types of esthetic brackets, two types of polycrystalline conventional ceramic brackets (20/40 and InVu) and one type of sapphire monocrystalline bracket (Radiance) in dry and artificial saliva wet settings. Also, to evaluate the influence exerted by artificial saliva on the friction forces of those brackets. Tests were performed in dry and artificial saliva wet setting (Oral Balance) by using an EMIC DL 10000 testing machine, simulating a 2 mm slide of 0.019 x 0.025-in rectangular stainless steel wires over the pre-angulated and pre-torqued (right superior canine, Roth prescription, slot 0.022 x 0.030-in) brackets (n = 18 for each bracket). In order to compare groups in dry and wet settings, the ANOVA was used. For comparisons related to the dry versus wet setting, the student t test was used for each group. The results showed that in the absence of saliva the Radiance monocrystalline brackets showed the highest friction coefficients, followed by the 20/40 and the InVu polycrystalline brackets. In tests with artificial saliva, the Radiance and the 20/40 brackets had statistically similar friction coefficients and both were greater than that presented by the InVu brackets. The artificial saliva did not change the maximum friction force of the Radiance brackets, but, for the others (20/40 and InVu), an increase of friction was observed in its presence. The InVu brackets showed, in the absence and in the presence of saliva, the lowest friction coefficient.

An in vitro comparison of resistance to second and third order archwire activations of three different varieties of esthetic brackets

When ceramic brackets were introduced as an esthetic alternative to the stainless steel brackets, it was a step ahead in the use of esthetic appliances for orthodontic treatment. Although ceramic brackets had overcome the drawbacks of the initial polycarbonate brackets such as staining and bracket slot distortion, they posed an altogether different problem. This was on account of the physical properties of the ceramic material, namely brittleness. The purpose of this study is to investigate the physical properties of three different varieties of esthetic brackets, i.e., "MXI" ceramic bracket, "Spirit MB" bracket (Ormco), a composite bracket with metal slot reinforcement and the third one fiber bracket, with silicious copolymer, Natura (Leone Co.). AIMS AND OBJECTIVE OF THE STUDY: The objective of this study is to compare the torsional resistance of the brackets and resistance of brackets to second order archwire activations. The strength of the selected brackets was more than sufficient to withstand orthodontic load without any fracture or deformation.

Mechanical and topographic evaluation of esthetic brackets and its relation to frictional resistance

Introduction: The purpose of this in-vitro study was to evaluate the frictional characteristics of conventional ceramic versus metal insert ceramic brackets in combination with stainless steel and Teflon-coated stainless steel archwires. Materials and Methods: Twenty brackets each, of ceramic and metal insert ceramic Maxillary canine preadjusted edgewise brackets 0.022 × 0.028 in slot) and 20 archwires, each of stainless steel and Teflon-coated stainless steel (0.019 × 0.025 in) were tested for frictional resistance. Friction was evaluated in a simulated Tidy's design apparatus on universal testing machine. The kinetic friction data were analyzed using Student's 't' test. The effects of surface characteristics on frictional resistance were qualitatively assessed using scanning electron microscope. Results: Metal insert ceramic brackets generated significantly lower kinetic frictional resistance than the conventional ceramic brackets with Teflon-coated stainless steel archwires ( P P Conclusion: Metal insert ceramic bracket with stainless steel archwire is the best possible combination among the materials studied because it generated the least frictional resistance during simulated tooth movement.

Digital analysis of staining properties of clear aesthetic brackets

To analyse the staining properties of clear orthodontic brackets using a digital analysis. In vitro, laboratory study A total of 500 tooth-coloured brackets from 10 brands (five ceramic and five plastic) were investigated. The cumulative discolouring effect of staining agents (tea, coffee, curry and red wine) were analysed at two consumption levels: light and heavy, based on a 6-month period of exposure. Study group brackets were immersed in the agents consecutively at 37°C. The control group was only exposed to artificial saliva. Samples were analysed digitally to obtain L*, a* and b* (lightness, red-green and yellow-blue) colour readings. Using these values, total colour change (ΔE*) at each level was also calculated. Three-way analysis of variance (ANOVA) test was used for statistical comparisons. L* and b* colour parameters showed significant differences (P<0·001) between different bracket groups, consumption levels and the type of exposure. However, the a* value only differed between bracket groups (P<0·001). According to the ΔE* values, ceramic brackets had less colour change than plastic brackets at the end of phase 1 for both the study and control groups. However, as consumption time increased, the rate of colour change decreased for the plastic brackets. In general, ceramic brackets demonstrated much more resistance to staining agents than plastic brackets. Both plastic and ceramic brackets showed changes in colour when exposed to heavy consumption of staining agents, with plastic brackets being the most affected.

ORIGINAL ARTICLE - Adhesion of Streptococcus mutans and Streptococcus sobrinus to different types of self-ligating brackets

Objective: The adhesion capabilities of different types of self-ligating brackets were measured with respect to Streptococcus mutans and Streptococcus sobrinus. Methods: Five types of self-ligating brackets (Clippy-C; Mini Clippy; Clarity-SL; Speed; Damon 3) were used for the experiment group and composite resin brackets (Spirit-MB), metal brackets (Victory) and polycrystalline alumina brackets (Clarity) were used for the control group. In order to assess adhesion of bacteria to the brackets, the brackets were cultured for 3, 6 and 24 hours in media containing bacteria and 20% sucrose. Results: There was no statistic difference in adhesion amount of Streptococcus mutans and Streptococcus sobrinus according to the types of brackets. A total adhesion amount according to bracket type was different. An extended incubation time increased adhesion amount. Observation under scanning electron microscope showed that Streptococcus sobrinus adhered more to Clippy-C and Victory rather than to Clarity-SL. Conclusions: Clarity-SL, a self-ligating esthetic bracket was confirmed to show lower bacterial adhesion to cariogenic bacteria, Streptococcus mutans and Streptococcus sobrinus group than other self-ligating brackets or conventional brackets, which suggests that proper use of self-ligating esthetic brackets might even be better in preventing tooth surface decalcification.

The effect of two different bracket types on the salivary levels of S mutans and S sobrinus in the early phase of orthodontic treatment

To determine the difference in the levels of Streptococcus mutans and S sobrinus in stimulated saliva in orthodontic patients with different bracket types (stainless steel and esthetic brackets) using polymerase chain reaction and cultivation method. Thirty-two patients, aged 13 to 30 years, were selected following these criteria: 1) orthodontic treatment indication, 2) systemic health, and 3) no tobacco and antibiotic consummation for three months prior to the commencement of the study. Patients were divided into two groups according to the bracket type; 16 patients formed the conventional bracket group (stainless steel brackets), and 16 patients formed the esthetic bracket group (plastic brackets). The levels of S mutans and S sobrinus in stimulated whole saliva samples were collected prior to fixed orthodontic appliance placement (T1) and 12 weeks after placement (T2), as were the Decayed, Missing, and Filled Surface Index (DMFS) and Oral Hygiene Index-Simplified (OHI-S). Mann-Whitney, Wilcoxon, and chi-square tests were used for statistical analysis. Statistical analysis (chi-square test) showed no difference in S mutans and S sobrinus counts among patients with different brackets at either T1 or T2. There was no difference in total bacteria counts after fixed orthodontic appliance placement. The number of colony-forming units of S mutans and S sobrinus in stimulated saliva samples does not seem to be significantly different between patients with stainless steel brackets and patients with plastic brackets.

Evaluation of the color stability of different types of polycarbonate brackets

Objective: To investigate the discoloring effect of certain foods and photoaging on the color stability of the three different types of polycarbonate brackets. Materials and Methods: Eighty four brackets were selected and divided into three groups: (1) Composite brackets with ceramic like filler (Silicon brackets); (2) Composite unfilled brackets (Spirit brackets) and (3) Polyoxymethylene brackets (Brilliant brackets). Seven specimens of three different esthetic brackets were exposed to tea, coke, curry and accelerated photogeing device to a xenon lamp to simulate natural day light. The brackets were analyzed at the beginning of the experiment and after 24 and 72 hours and 25 days of exposure. Color measurements were performed by means of Vita Easy shade Spectrophotometer according to CIELCh coordinates lightness, chroma and hue and color changes (∆E) were computed. Results: Almost all investigated brackets showed clinically unacceptable discoloration during in vitro exposure to food dyes and UV light with the exception of the polyoxymethylene brackets which showed nonperceptible color change after storage 25 days in coke and UV. Tea and curry discolor all brackets and showed a sharp increase in discoloration after 24 hour. Most of the brackets became yellower after UV light exposure. Conclusions: These current in vitro findings indicate that even newly developed plastic brackets, consisting of composite materials or modern polymers (polyoxymethylene) may have clinically unacceptable color stability in the long-term.

Influence of optical properties of esthetic brackets (color, translucence, and fluorescence) on visual perception

The aims of this study were to evaluate the optical properties of esthetic brackets and determine their influence on visual perception. Eighty esthetic brackets of 16 commercial brands were tested. The color and translucency of the brackets, as well as the color of the maxillary central incisors of 40 subjects, were measured with a spectrophotometer. The fluorescence of the brackets was determined by duly calibrated appraisers. The color differences between the brands of brackets and the teeth were calculated. Data were analyzed by using 1-way analysis of variance; the Scheffé multiple comparison test was used to establish the difference between brands of brackets, (α = 0.05). The color parameters L ∗ a ∗ b ∗ of nontranslucent brackets ranged from 49.4 to 86.0, -1.6 to 3.0, and 1.9 to 14.6, respectively. The direct transmission of light ranged from 0.0% to 38.8% transmittance. No bracket showed fluorescence. The color and translucency, as well as the color difference, of the brackets were influenced by brand (P <0.01). The optical properties of esthetic brackets have a direct influence on visual perception; translucent brackets and the nontranslucent InVu (TP Orthodontics, LaPorte, Ind) brackets were less visually perceptible.

Comparative assessment of clinical performance of esthetic bracket materials

To compare the alterations in esthetic appearance and slot morphology/integrity of two main types of esthetic brackets caused after clinical use. Sixteen ceramic (CR) and 16 plastic (PR) central incisor brackets were obtained from 16 young adult patients at the end of treatment in a prospective randomized manner. As controls, 12 ceramic (CC) and 12 plastic (PC) nonused brackets were also examined. Three representative slot width measurements were obtained through micrometric microscopy. Visual inspection of optical microscopy images, surface electron microscopy (SEM), and energy-dispersive x-ray spectroscopy (EDS) were also performed. Intraoral exposure time varied from 5 to 20 months (mean, 12.4; P = .73). Two-way analysis of variance revealed significant differences in slot width among the different materials and a significant interaction between the material effect and its status (P < .001). Bonferroni post hoc tests on material × status effect showed significant differences between CC (95% confidence interval [CI]: 434.5, 447.0) vs PC (95% CI: 460.2, 472.8), CC vs CR (95% CI: 453.2, 464.4), and PC vs PR (95% CI: 448.8, 458.9). Interestingly, a significant difference was not detected for CR vs PR. Slot width was correlated with the time under clinical use only for plastic brackets (PR: r = -.64, P < .01). Visual inspection of the optical microscopy images did not reveal any major macroscopic morphological disfigurements or significant discolorations. However, a rough and irregular slot wall surface was evident after clinical use (also with SEM), especially in the bottom of the slot. Both bracket types presented adequate clinical performance at least for the time period studied and in terms of esthetic appearance and morphologic integrity.

The effect of light intensity and curing time of light emitting diode on shear bond strength using different types of bracket's materials

Background: This study was intended to evaluate the effect of two LED devices which has different light intensity and curing time on the shear bond strength (SBS) using stainless steel and two other esthetic brackets. Materials and method: Sixty first premolar teeth were selected. Three types of orthodontic brackets were used in this study: stainless-steel brackets, the other two types are esthetic ceramic brackets. Two high intensity LED units were used, the first one was of a lower intensity (HANGZHOU SIFANG, China), the output power 1200 mW/cm2, the second source had the higher intensity (FlashMax P3, Denmark) which has power intensity of 4000 mW/cm2. The teeth were divided into two groups (Aand B) of 30 teeth each. Group A was used for testing HANGZHOU SIFANG device in standard cure time (20s) , while the group B was used for testing Flash Max P3 device in fast curing mode(6s). A and B groups were further subdivided according to bracket type into three subgroups of 10 teeth each. SBS of all subgroups were tested by using an Instron universal testing machine, ARI was assessed at (20X) magnification. Results: The clinically acceptable SBS were excelled in both the standard and fast curing mode groups for all bracket types, significant differences were found only when comparing the Pure with the other two types of brackets in the same group. Comparing each bracket type between group A and group B reveals a significant difference only at stainless-steel type brackets. Conclusions: the new high intensity curing devise gave comparable SBS to the LED units previously available with shorter time.

Adherence of Streptococcus mutans and Candida albicans to different bracket materials

Objective:To quantify the adherence of Streptococcus mutans and Candida albicans on brackets made of stainless steel, plastic, ceramic, titanium, and gold, and to evaluate the various sites of adherence of these microorganisms with scanning electron microscopy (SEM).Materials and Methods:Brackets made of stainless steel, plastic, ceramic, titanium, and gold were used. The adherence of S. mutans and C. albicans were studied. The brackets were placed in flat-bottomed vials containing basal medium with 20% sucrose added; the flasks were inoculated with each of the microbial suspensions. The samples were incubated at 37°C for 48 h, after which the brackets were removed. The cells adhering to the glass were counted and the brackets were studied with SEM.Results:When evaluated together, the adherence of S. mutans and C. albicans was increased in the ceramic bracket group. When evaluated separately, metallic brackets had increased number of colony-forming units (CFUs) of S. mutans and the use of titanium brackets increased the CFUs of C. albicans. SEM demonstrated that the adherence of S. mutans and C. albicans together varied according to the bracket materials, with ceramic having the greatest and stainless steel having the least adherence.Conclusions:Oral hygiene may be of greater concern with esthetic brackets since this study shows that microbial adhesion is greater with these brackets.

Commentaries on scientific papers published in this edition

As Josef Albers said ‘we never really perceive what colour is physically’, and if a patient’s perception of ‘colour’ is not agreeable, then they are liable to be unhappy with the treatment even if it is clinically perfect, hence, the reason for the development of aesthetic brackets. In this paper, the authors have attempted to evaluate effect of the bracket on the perceived colour of a shade tab. The problem with this is that tabs are not teeth, and as the brackets were not bonded to the tab, one wonders why a tooth was not used. This is given as a limitation of the experimental design. The choice of background is a major influence on perceived colour and the clinical relevance of a white background is uncertain. However, the experiment was standardized and an effect of bracket type on perceived colour was demonstrated, although it would have been useful to have a ‘patient’ give an opinion on the presence or absence of a colour difference. The impact of the paper is reduced by the authors not clearly indicating if they used more than one bracket of each type, or just one bracket which they measured three times. Allied to this is a confusing analysis of the data where they switch between twoand one-way ANOVA where the use of contrasts or margins would have allowed a full analysis of the twoway model. This was a useful experiment which demonstrates the effect of the underlying tab/tooth on the perceived colour. However, as these brackets are widely used in clinical practice, patients must be happy with them, which leads to a further question of whether patients will tolerate more of colour difference with orthodontic treatment than with a restoration.