An assessment of the pH changes and metal ions released into artificial saliva by fake orthodontic braces.

BACKGROUND: This present study assesses changes in the pH as well as the metal ions that fake braces release into artificial saliva (AS) using a pH meter and inductively coupled plasma atomic emission spectroscopy (ICP-AES), respectively. METHODS: Three sets of fake archwires (AWs) and brackets (Bs) as well as a set of controls were immersed in AS and placed in an incubator shaker at 50 rpm and 37°C. At Days 0, 1, 7, 14, 21, and 28, the pH of the AS medium was measured and 3.0 ml of AS was collected and stored at -20°C for elemental analysis. RESULTS: Significant changes in pH were observed on Days 0, 1, 7, 14, 21, and 28 in the AS of the AW group. However, these changes were only observed in the B group on Days 0 and 7. The fake samples released a large quantity of sodium (Na), potassium (K), and calcium (Ca) ions, at concentrations exceeding 100 mg/L, post-28 days of immersion. The control and fake braces samples released other ions; such as lithium (Li), magnesium (Mg), barium (Ba), chromium (Cr), copper (Cu), lead (Pb), and aluminium (Al); at concentrations that did not exceed 10 mg/L. CONCLUSIONS: The pH of the AS of all the samples increased post-incubation. Only 10 ions; namely, Na, Li, K, Mg, Ca, Ba, Cr, Cu, Pb, and Al; were detected in the AS.

Antimicrobial and mechanical assessment of cellulose-based thermoformable material for invisible dental braces with natural essential oils protecting from biofilm formation.

Controlling biofilm formation in the oral cavity during orthodontic treatments is crucial. Therefore, antimicrobial surfaces for invisible dental appliances are of interest to both therapists and patients. Here we present a cellulose-based thermoformable material used for invisible braces that can be loaded with essential oils (EOs) having antibacterial and antifungal properties. We hypothesize that this material can absorb and release EOs, thus providing an antimicrobial effect without compromising the safety and mechanical properties necessary for dental invisible braces. Conventional microbiology and isothermal microcalorimetry analyses revealed that the thermoformable material loaded with essential oils significantly delayed the biofilm formation of oral streptococci (S. mutans and S. mitis) under static conditions (p < 0.05) and while simulating saliva flow (p < 0.05). In addition, cytotoxicity tests (ISO 10993-5), revealed that the loaded material is well tolerated by human gingival fibroblasts. Finally, the loading with antibacterial agents did not significantly alter the mechanical properties and stability of the material (initial force (p = 0.916); initial stress (p = 0.465)). Compared to gold-standard clear aligner materials, this material offers a reliable transmission of forces for orthodontic treatments. Moreover, this approach exhibits the potential for acting as an oral drug delivery platform for multiple compounds.

Comparison of bracket bonding between two CAD/CAM guided bonding devices: GBD-U vs GBD-B.

OBJECTIVE: To compare the bracket bonding accuracy, efficiency, reproducibility, and three-dimensional (3D) printing duration of the computer-aided design/computer-aided manufacturing (CAD/CAM) unilateral contact guided bonding device (GBD-U) and the bilateral contact guided bonding device (GBD-B) in vitro. METHODS: Five resin dental model sets were scanned and virtually bonded with brackets. GBD-U and GBD-B were designed and 3D printed for each model. GBD-Us had guide blocks that fit the occlusal sides of the bracket tie-wings, while GBD-Bs had guide arms that fit the occlusal and distal sides of the tie-wings. Five orthodontic residents were recruited to bond brackets on the same 3D-printed copies of resin models in a dental mannequin using GBD-Us and GBD-Bs, respectively. The time for 3D printing of GBDs and bracket bonding was recorded. The linear and angular deviations between the bonded brackets and the virtually bonded ones were measured. RESULTS: A total of 50 sets of resin models (1000 brackets/tubes) were bonded. The time for 3D printing and bracket bonding was shorter for GBD-Us (41.96 mins/6.38 mins) than for GBD-Bs (78.04 mins/7.20 mins). In both devices, 100% linear deviations and over 95% angular deviations were below 0.5 mm or 2°, respectively. Deviations in the mesiodistal dimension, torque, angulation, and rotation were significantly lower in the GBD-U group (P<0.01). High inter-operator reproducibility of bracket bonding was confirmed for both devices. CONCLUSION: GBD-U was more time-efficient in 3D printing. Both GBDs showed clinically acceptable accuracy, whereas GBD-U had higher bonding accuracy in the mesiodistal dimension, torque, angulation, and rotation than GBD-B. CLINICAL SIGNIFICANCE: CAD/CAM GBD-U provides high bracket bonding accuracy in a time-efficient manner and has the potential to be clinically applied.

Comparative assessment of dental and basal arch dimensions of passive and active self-ligating versus conventional appliances : A randomized clinical trial.

PURPOSE: In this parallel, three-arm, single-center randomized trial, the dental and basal arch dimensions after orthodontic treatment using conventional brackets and passive and active self-ligating (SL) brackets were compared. METHODS: Patients needing comprehensive orthodontic treatment were randomly allocated to the active SL, passive SL, or conventional brackets (control) group. All patients were treated with a standardized arch wires sequence. Eligibility criteria included class I malocclusion in the permanent dentition, crowding (4-6 mm), and adequate oral hygiene. The primary outcome was intermolar width, based on cone beam computed tomography (CBCT) scans. Secondary outcomes were maxillary and mandibular widths in the canines and premolars regions, dental arch depth, buccolingual inclination, and alignment duration. Blinding of outcome assessment was implemented. Patients were followed every 4 weeks until insertion of the stainless steel 0.019â€¯× 0.025 wire. Mean values were computed from CBCT sections, and data were analyzed using a one-way analysis of variance. RESULTS: In all, 66 patients (ages 18-25 years) were randomized into a 1:1:1 ratio; 7 patients dropped out before treatment initiation. Examining dental arch dimensions in the canine and premolar regions showed that expansion of the maxillary dental arch was greatest in the passive SL brackets group, less in the active SL brackets group, and lowest in the control group (P < 0.01). Changes in maxillary intermolar width between the three groups were not significant, and changes in basal arch dimensions, depth of dental and basal arches, buccolingual inclination, and alignment duration were similar in the three groups. CONCLUSIONS: Self-ligating brackets were not more effective than conventional brackets when examining intermolar width, basal transverse dimensions, depth of the arch, and alignment duration.

An assessment of mineral concentration of dental enamel neighbouring hypothetical orthodontic brackets using X-ray microtomography.

OBJECTIVES: Differences in the mineral concentration (MC) level of dental enamel may represent a precursor of white spot lesions adjacent to fixed orthodontic brackets. The aim of the current in vitro study was to compare the MC level central, occlusal and cervical to orthodontic attachments. METHODS AND MATERIALS: A total of 16 enamel blocks were obtained from sound human premolar samples extracted for orthodontic reasons. The buccal portion of the dental enamel blocks was divided into central, occlusal, and cervical regions and then imaged and measured to calculate the level of MC using quantitative X-ray microtomography methods (XMT) at each site. RESULTS: There was a substantial variation in the mineral concentration with the lowest level being detected in the cervical region when compared with other regions. The MC of the gingival zone was significantly lower than that of the middle zone (P<0.05) and was insignificantly lower than that of the occlusal zone. CONCLUSION: Within the limitations of the current study, it can be concluded that the cervical region of the permanent enamel had the lowest mineral concentration using XMT. The cervical region may therefore be more vulnerable to the development of white spot lesions (WSLs) adjacent to a fixed orthodontic appliance during orthodontic treatment. CLINICAL SIGNIFICANCE: Using X-ray microtomography lower mineral concentration in the cervical region of the enamel was observed. This may make these areas particularly susceptible to demineralisation during fixed appliance-based orthodontic treatment and may influence the bond strength of fixed orthodontic attachments.

Reliability of qualitative and quantitative assessment of adhesive remnants after debonding of ceramic brackets bonded with Transbond™XT on human molar teeth: An in vitro study.

OBJECTIVE: To test the hypothesis that there are any differences between qualitative and quantitative methods of adhesive remnants index (ARI) scores on the buccal surfaces of the upper molar. MATERIALS AND METHODS: The study included 34 upper first human molars. After etching for 20seconds by using 35% orthophosphoric acid (Ultra-Etch, Ultradent Products Inc., USA) and then rinsed with distilled water for 15seconds, the adhesive (Transbond™XT, 3M™, USA) was applied and cured with the polymerization lamp (Bluephase Style, Ivoclar Vivadent, Liechtenstein) for 10seconds. Ceramic brackets (Damon® Clear™, Ormco, USA) were placed by composite (Transbond™XT, 3M™, USA) on the buccal surface of the molars. Following 24-hour storage of the samples in distilled water (WB-12, Phoenix Instrument, Gabsen, Germany) at 37°C, the brackets were debonded using a debonding plier (Damon Clear Debonding Plier, Ormco, USA). ARI and a modified ARI-scoring system were used. Three independent observers scored the ARI with the naked eye under 10x, 20x, and 32x magnifications using Stereomicroscope Stemi DV4 (Zeiss, Germany). Afterward, the digital microscope VHX-5000 (Keyence, Japan) under 50x magnification was used for the quantitative analysis of the adhesive remnants by just one evaluator. The Fleiss' Kappa-coefficient test was used to assess interrupter reliability. RESULTS: Fleiss' Kappa-coefficient test show that the highest amount of agreement between observers is observed using the naked eye for both of the scoring methods P<0.001. Increasing the magnification led to the moderate decrease of inter-observer agreement. For evaluations with naked eye, a higher agreement is observed for the modified ARI score compared to the ARI scored. The agreement between the quantitative and qualitative evaluation of the ARI score rose with increasing magnification. CONCLUSION: The assessment of adhesive remnants should be done either with naked eye or under 10x magnification, as they showed the highest rate of intra-observer agreement.

Assessment of chemical, ultrasonic, diode laser, and Er:YAG laser application on debonding of ceramic brackets.

BACKGROUND: Risk of enamel damage that often accompanies ceramic brackets debonding raises the demand of finding an optimal method for debonding of them without adverse effects. Different techniques were proposed in an attempt to facilitate their debonding. Comparison of these techniques is crucial. The aim of this study was to evaluate and compare different techniques for debonding of ceramic brackets in terms of shear bond strength and adhesive remnant index. MATERIALS AND METHODS: A total of 100 extracted premolars were randomly allocated into 5 groups. Ceramic brackets were then bonded to teeth using light cure composite resin. Among test groups; group I: served as control, group II: chemical aided debonding via peppermint oil, group III: ultrasonic aided debonding, group IV: diode laser aided debonding, and group V: Er:YAG laser aided debonding. Brackets were shear tested using universal testing machine followed by ARI assessment and evaluation of enamel microstructure was performed using scanning electron microscopy. RESULTS: A significantly lower shear bond strength was found in ultrasonic, diode, and Er:YAG laser groups. However, no significant difference was found in the chemical group. A significantly higher adhesive remnant index was found solely in Er:YAG laser group with minimal enamel microstructure alterations. CONCLUSIONS: Er:YAG laser is a promising tool in debonding ceramic brackets. Ultrasonic and diode laser significantly reduced shear bond strength. Yet, adhesive remnant index in both groups revealed no difference. Chemical aided debonding had little effect and hence, it cannot be recommended without further development.

Validation of clinical photography and a laser fluorescence device for assessment of enamel demineralization during multi-bracketed fixed orthodontic treatment.

AIM: To compare the validity of DIAGNOdent pen™ 2190 and clinical photographs in the diagnosis (presence or absence) and assessment of white spot lesions (WSLs) during multi-bracketed fixed orthodontic treatment. METHODS: A total of 1607 readings from 99 patients were obtained using DIAGNOdent pen™ 2190, clinical photographs, and visual assessment criteria to assess WSLs at 6 -, 12- and 18 months after bonding of brackets. Receiver operating characteristic curves were constructed, and areas under the curve (AUC) were calculated to assess the presence or absence of WSLs and distinguish the severity of WSLs as slight or severe. Sensitivities, specificities, and AUC were calculated for outcomes at an alpha of 0.05 and 95% confidence intervals (CIs). RESULTS: The values of sensitivity and specificity of DIAGNOdent pen™ 2190 were found to be 0.78 and 0.83, respectively, to distinguish presence/absence of WSLs with good accuracy (AUC= 0.855; 95% CI: 0.820-0.889) and for digital photographs, accuracy was excellent (AUC= 0.973, 95% CI: 0.956-0.991) with sensitivity and specificity of 0.96 and 0.99, respectively. However, the accuracy of DIAGNOdent pen™ 2190 was poor (AUC= 0.543, 95% CI: 0.418-0.668) in delineating slight and severe WSLs with a sensitivity of 0.31 and specificity of 0.83; while the values of sensitivity and specificity for distinguishing slight or severe lesions for clinical photographs were 0.96 and 0.99, respectively with excellent accuracy (AUC=0.978, 95% CI: 0.936-1.000). CONCLUSIONS: Clinical photographs had better validity than DIAGNOdent pen™ 2190 in diagnosis and assessment of severity of demineralized lesions during multi-bracketed fixed orthodontic treatment.

Super-elasticity in vitro assessment of CuNiTi wires according to their Austenite finish temperature and the imposed displacement.

OBJECTIVES: To assess the super-elasticity of CuNiTi wires (Ormco, Glendora, Calif) according to their Austenite finish temperature (Af) and to the imposed displacement. The secondary objective was to compare the wire dimensions with the stated measurements and to study interbatch variability. MATERIALS AND METHODS: 10 types of CuNiTi wires (Ormco, Glendora, Calif) (n = 350) were investigated at 36 ± 1°C, with conventional brackets (Victory Series, 3M Unitek, Monrovia, Calif). Tensile test with coronoapical displacement ranging from 1 to 5 mm of the canine bracket was imposed. The wire dimensions were initially measured from two batches (n = 10). RESULTS: Dimensional heterogeneity varied by ± 2.00% compared to the manufacturer's data, and even up to 5.54% for 0.014-inch CuNiTi (P = .00069). However, all unloading forces were reproducible. In decreasing order, the forces delivered by a CuNiTi 27 were greater than those with CuNiTi 35 and 40. The super-elasticity was expressed only for displacements of 1 to 2 mm, at best up to 3 mm for 0.014-inch CuNiTi 27. CONCLUSIONS: The value of Af as well as the amount of imposed displacement seem to influence the expression of the super-elasticity of CuNiTi wires and the amount of corrected malocclusion. Among the tested wires, under these experimental conditions, 0.014-inch wire could be suitable as a first archwire. CuNiTi 35, therefore, seems to offer the best compromise among the force level, the expression of super-elasticity and the amount of malocclusion correction.

Assessment of frictional resistance and surface roughness in orthodontic wires coated with two different nanoparticles.

Several mechanical and biological factors may change the orthodontic wire frictional resistance (FR). Titanium dioxide (TiO2 ) and silica dioxide (SiO2 ) nanoparticle (NP) coatings may be used to improve the characteristics of materials, reducing FR between archwire and bracket. This in vitro study aimed to evaluate the FR of orthodontic wires with and without coating in both dry and wet environments and measure the surface roughness (SR). One hundred and eighty segments of rectangular Cr-Ni orthodontic wires (Morelli Co, Brazil) were divided into three groups according to the NP coating applied: TiO2 group; SiO2 group; and control group. The SR parameters were measured in an optical profilometer, the surface morphology was analyzed with scanning electron microscopy (SEM), and FR was performed in a universal testing machine in dry and wet environments (n = 30). The statistical analysis was performed using the Generalized Estimated Equations model with a Bonferroni post-test (α = 0.05). It was observed that SiO2 NP coating decreased FR significantly when compared to the TiO2 and control groups, in both environments (p < .001). The SiO2 and TiO2 groups presented statistically lower SR than the control group and were similar to each other (p < .001). The SiO2 group presented the lower depth of Valley parameter than the TiO2 group (p < .001). The SEM showed that the TiO2 coating had the most heterogeneous surface morphology than the SiO2 and control groups. The orthodontic wires with NP coating modified the FR and morphology. The SiO2 coating reduced FR in both dry and wet environments and decreased SR. Titanium dioxide (TiO2 ) and silica dioxide (SiO2 ) nanoparticles coatings may be used to reduce frictional resistance (FR) between archwire and bracket as well as to improve surface morphology. The SiO2 coating reduced FR in both dry and wet environments and decreased the SR of Cr-Ni orthodontic wire. The TiO2 coating promoted the most heterogeneous surface morphology of Cr-Ni orthodontic wire.

Bond assessment of enamel conditioned with Er, Cr: YSGG laser and methylene blue photosensitizer activated by photodynamic therapy to orthodontic metallic brackets.

AIM: To assess bond integrity and failure mode after enamel pretreated with conventional and contemporary conditioning methods were bonded to metallic brackets (MB). MATERIAL AND METHODS: Forty maxillary central incisors were selected and disinfected. All specimens were mounted up to the cement-o-enamel junction and divided into four experimental groups randomly based on the enamel conditioning technique. Photodynamic therapy (PDT) was used to condition enamel in group 1, Total-etch and rinse (TER) was used to treat samples in group 2, Specimens in group 3 were conditioned with ECL, and samples in group 4 surface pretreated with SEP. Bonding of MB was performed on the surfaces of all the specimens with a Transbond XT. Specimens from all investigated groups were positioned on a universal testing machine maintaining buccal surfaces similar to the direction of the force. After bracket debonding bond failure was assessed using ARI. The bond integrity of all four groups was compared using analysis of variance (ANOVA). Post hoc Tukey test was used for pairwise comparison among different groups. RESULTS: Group 2, TER+MB (15.38±0.14 MPa) displayed the highest bond value whereas the lowest values of SBS were exhibited by group 1, PDT+MB (10.11±0.17 MPa). The inter-group comparison revealed that specimens of group 2 and group 3, ECL+MB (14.61±0.55 MPa) demonstrated comparable bond strength (p>0.05). CONCLUSION: Enamel conditioned with TER and ECL demonstrated comparable SBS. However, bond integrity after PDT and SEP (self-etch primer) surface treatment of enamel bonded with MB significantly lowered bond values.

Assessment of Microleakage under Stainless Steel Orthodontic Brackets Bonded with Various Adhesive Systems: An In Vitro Study.

AIM AND OBJECTIVE: The aim of this study was to evaluate the extent of microleakage beneath stainless steel orthodontic brackets bonded with different adhesive systems. MATERIALS AND METHODS: Freshly extracted 60 human premolar teeth from mandibular arch were included in this study. After sterilizing all teeth, they were stored in thymol solution of 1% for further preparation. Acrylic blocks were used to mount the teeth in a way their roots were totally implanted up to the cement enamel junction in acrylic with crown being visible. A 0.022 slot, stainless steel preadjusted edgewise premolar brackets were taken. Sixty premolars were categorized randomly into three groups (20 premolars in each group) as follows: group I: flowable composite, group II: Fuji Ortho LC, group III: Transbond XT. Later, all the samples were subjected to thermocycling and tested immediately and 24 hours after water storage. The samples were submerged for 24 hours in methylene blue solution (2%) at room temperature. A ×20 magnification stereomicroscope was used to examine all samples. RESULTS: The lowest microleakage (1.34 ± 0.20) was shown by Transbond XT restored teeth, followed by flowable composite group (1.79 ± 0.32) and Fuji Ortho LC group (2.98 ± 0.13). An analysis of variance showed statistically significant differences among various adhesive systems. A statistically significant difference (p <0.05) among groups I and II, and groups II and III adhesive materials was seen. CONCLUSION: This study demonstrated microleakage in all the examined adhesive groups but the lowest microleakage was found with Transbond XT group followed next by Filtek Z350 XT group and Fuji Ortho LC group. CLINICAL SIGNIFICANCE: Due to microleakage, the bacteria and fluids present intraorally penetrate through the gaps along the enamel-adhesive boundary. This penetration results in significant esthetic and clinical complications. Such problems related to microleakage can be addressed with the use of an appropriate adhesive agent.

Three-dimensional assessment of virtual bracket removal for orthodontic retainers: A prospective clinical study.

INTRODUCTION: Computer-aided design and manufacturing of orthodontic retainers from digitally debonded models can be used to facilitate same-day delivery. The purpose of this prospective clinical study was to validate a novel technique for virtual bracket removal (VBR) in-office, comparing the accuracy with 2 orthodontic laboratories that use VBR for retainer fabrication in the digital workflow. METHODS: The sample consisted of 40 intraoral scans of 20 patients. Four groups were compared. The scans without brackets were used as a control group. VBR was performed by 3 groups: In-office VBR (Software Meshmixer, version 3.5.474; Autodesk, San Rafael, Calif), Orthodent Laboratory (ODL; Buffalo, NY), and New England Orthodontic Laboratory (NEOLab; Andover, Mass). The virtually debonded models were superimposed onto the control models using surface-based registration. Regional 3-dimensional Euclidean distances between surface points of superimposed models were calculated for comparative analysis of surface changes after VBR using Vector Analysis Module (Canfield Scientific, Fairfield, NJ) software. RESULTS: The accuracy of VBR using the Meshmixer did not differ significantly from the VBR protocols used by the 2 laboratories. However, there was a statistically significant difference between the 2 laboratories, with ODL showing lower accuracy than NEOLab. Although some differences were statistically significant, they were very small and not considered clinically relevant. There was also a statistically significant difference between the 3 tooth segments (incisors, canines/premolars, and first molars), with VBR of the first molars and second premolars showing the least accuracy. CONCLUSIONS: The VBR techniques using the in-office Meshmixer, ODL, and NEOLab were considered accurate enough for the clinical use of orthodontic retainers fabricated from printed models.

[Assessment of dental arches expansion using ligature and passive self-ligating braces in combination with Pitts broad arches and early elastics]. / Otsenka rasshireniya zuboal'veolyarnykh dug u patsientov pri ispol'zovanii ligaturnykh i passivnykh samoligiruyushchikh breket-sistem v sochetanii s dugami Pittsa shirokoi formy i rannei elastichnoi tyagi.

THE AIM OF THE STUDY: Was to analyze the effectiveness of the use of Pitts Broad and early elastics in the treatment of patients with narrowing and deformation in dentition. MATERIALS AND METHODS: The results of orthodontic treatment of 46 adult patients with narrowing and deformation in dentition are presented. Patients were separated in 2 groups, depending on the algorithm of treatment: group 1 - using the braces of passive self-ligation, Pitts Broad and early short elastics; group 2 - using ligature braces and archwires Orthos. RESULTS: Biometric analysis of the diagnostic models of the 1st group after treatment showed a significant increase in the area of the premolars on the upper (between premolars - 39.8±0.4 mm, between molars - 48.3±0.5 mm) and lower (between premolars - 37.1±0.5 mm, between molars - 46.3±0.6 mm) jaws compared to the data before treatment. Biometric analysis of the diagnostic models of the 2d group showed that expansion in the area of the molars was achieved in a much smaller volume in the upper and lower jaws, compared with the 1st group (upper jaw: between premolars - 35.7±0.4 mm, between molars - 43.5±0.5 mm; lower jaw: between premolars - 33.2±0.3 mm, between molars - 42.3±0.5 mm). CONCLUSION: The passive self-ligation system in combination with protocol of Pitts Broad already contributes the expansion of dentition in aesthetically significant areas (distal regions) in the early stages of treatment. Using of early light elastics provides an early control of the lateral tooth torque, which allows achieving a harmonious and wide smile at the end of treatment.

Non-Invasive Optical Coherence Tomography Data-Based Quantitative Algorithm for the Assessment of Residual Adhesive on Bracket-Removed Dental Surface.

The aim of this study was to quantitatively assess the residual adhesive on orthodontic ceramic bracket-removed dental surface. In orthodontic process, ceramic bracket was repeated debonding physically, then the adhesive remained on the dental surface. The residual adhesive caused a lack of adhesive strength between dental and ceramic bracket. Since commonly used adhesive in orthodontics is translucent, residual adhesive is hard to be detected with conventional microscopes. Therefore, 1310 nm center wavelength swept-source OCT system based on laboratory customized image processing algorithm was used for the precise detection of residual adhesive on tooth surface. The algorithm separates residual adhesive from dental surface by comparing the height of adjacent B-scan images, while providing color-scaled images emphasizing the thickness information of residual adhesive. Finally, the acquired results were compared with microscopic and adhesive remnant index scoring gold standards, while the comparison confirmed the potential merits and the improvements of the proposed method over gold standards.

Assessment on the Precision of the Orthodontic Bracket Slot Dimensions Using Micro-computed Tomography (Micro-CT).

AIM: To evaluate the precision of the orthodontic bracket slot dimensions of 0.022 inch and to compare them with those of the manufacturers' specifications. MATERIALS AND METHODS: The slots of upper-right central incisor brackets (n = 5) from 11 commercial bracket systems of three different manufacturers (3M Unitek: Victory Mini Metal, Clarity, SmartClip, Clarity SL; ORMCO/SYBRON: Mini Diamond Twin, Damon Q, Damon Clear; Dentsply/GAC: Ovation, Mystique, In-Ovation R, In-Ovation C) were measured. The orthodontic brackets were scanned using micro-computed tomography (micro-CT), and the bracket slots were measured using micro-CT images. The slot was measured at four different surfaces (occlusal, gingival, base, and face) for both mesial and distal sites. Data were subjected to ANOVA and unpaired t-tests. A p-value of ≤0.05 was considered statistically significant. RESULTS: All brackets had slot dimensions that were significantly larger (p < 0.05) than the stated 0.022 inch. 3M-victory were 11.99% larger (0.02509 inch) and the closest to the stated dimension and the ORM-Damon C were 24.07% larger (0.02948 inch) than the quoted slot size of 0.022 inch. Comparison between mesial and distal sides showed that 91% of the bracket slots were asymmetrical at their bases and 100% asymmetrical at their faces. All of the bracket system showed divergent walls from base to face with values ranging from 1.96 (3M-SmartClip) to 26.58% (ORM-Damon C). CONCLUSION: The actual measurements of 11 bracket systems from three different manufacturers were more substantial than the manufacturers' specifications, and the walls of the slots diverged from the bracket bases in all of the tested bracket system. CLINICAL SIGNIFICANCE: Orthodontic bracket slots vary significantly from that of the manufacturers' specification. The orthodontist should anticipate such shortcomings and be able to modify treatment mechanics through additional wire bending in three spatial planes.

A comparative assessment of transfer accuracy of two indirect bonding techniques in patients undergoing fixed mechanotherapy: A randomised clinical trial.

OBJECTIVES: To assess the transfer accuracy of three-dimensional (3D) printed transfer trays and compare them with transfer trays made up of polyvinyl siloxane (PVS) for use in indirect bonding. DESIGN: This was a two-arm parallel prospective randomised controlled trial. SETTING: The trial was undertaken at the outpatient department of a dental college. PARTICIPANTS: A total of 30 patients (18 men, 12 women) were randomly allocated to two groups. METHODS: The inclusion criteria included patients with permanent and fully erupted dentition (age range = 17-24 years), Angles class I malocclusion with crowding <3 mm requiring non-extraction treatment, good oral hygiene and no previous history of orthodontic treatment. Blinding was applicable only for outcome assessment. Indirect bonding was performed by the primary investigator for both the groups. Digital images of the pre-transfer and post-transfer brackets were obtained by means of an intra-oral scanner and compared using software. Superimpositions of pre- and post-transfer images were done to determine the transfer error for linear and angular variables for all tooth types. RESULTS: A total of 600 teeth were bonded, 300 each for both groups. Statistically significant differences were observed in all dimension between the two groups, with 3D-printed trays being more accurate than PVS trays except in the vertical dimension (P < 0.05). The prevalence of clinically unacceptable transfer errors revealed that most of the transfer errors were in the vertical dimensions for 3D-printed trays. CONCLUSION: 3D-printed trays are more accurate than PVS trays except for transfers in vertical dimension.

Influence of photodynamic therapy and different conventional methods on conditioning of lithium di silicate ceramics bonded to metallic brackets: An assessment of bond strength.

AIM: The aim of the current study was to assess the effect of different conditioning methods on Lithium di silicate (LDC) employing conventional and contemporary regimes bonded to metallic brackets. MATERIAL AND METHODS: 70 discs of LDC were prepared and polished to attain smooth surface. Samples were allocated into seven groups according to ceramic surface conditioning. Group 1 surface treated with Er-YAG laser and saline (S), Group 2 PDT using MBP + S, Group 3 H F + S (control), Group 3 HF (Hydrofluoric acid) + saline, Group 4 HF (Hydrofluoric acid) + ultrasonic bath (UB) + S, Group 5 sand blasting the glass ceramic surface with 120 um Al2O3, Group 6 LDC surface conditioned with SECP(Etch and Prime) and Group 7 ECL(Laser) + S on was irradiated on LDC. Both chemical and mechanical surface treatments of LDC were followed by placement of metallic brackets. Samples were arranged in universal testing machine for shear bond strength (SBS) testing. Bond failure of brackets were assessed using ARI. To assess and compare the mean and standard deviations (SD) among experimental groups analysis of variance (ANOVA) was employed. All treatment combination means were compared using the post hoc Tukey's multiple comparison test at a significance level of (p ≤ 0.05). RESULTS: SBS values of Group 2 H F acid + S displayed highest bond durability (22.28 ± 1.09 MPa). Whereas, specimens in Group 4 surface treated with 120 µm Al2O3 displayed lowest SBS scores (11.81 ± 0.55 MPa) and these bond scores were comparable to PDT using MBP + S (12.54 ± 1.09 MPa) (p > 0.05). LDC surface treated by ECL + S (21.11 ± 3.85 MPa), HF + UB + S (19.28 ± 0.52 MPa) exhibited results comparable to HF acid + S (p > 0.05). CONCLUSION: LDC conditioned with HFS still remains as gold standard. Use of PDT for surface treatment of LDC and bonded to metallic bracket is not recommended as it results in decreased bond durability. Use of ECL-S and HF + UB + S has a potential to be used alternatively to HFS for LDC conditioning.

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

AIM: 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). MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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. CLINICAL SIGNIFICANCE: 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.

Clinical outcomes of lingual fully customized vs labial straight wire systems : Assessment based on American Board of Orthodontics criteria.

PURPOSE: To evaluate orthodontic treatment outcome in patients treated with a lingual appliance (Incognito™ Appliance System, 3M Unitek, Monrovia, CA, USA) versus patients treated with a labial appliance (Victory series™, 3M Unitek, Monrovia, CA, USA). METHODS: A total of 72 patients were retrospectively analyzed. The complexity of each case was evaluated using the American Board of Orthodontics (ABO) Discrepancy Index (DI), and orthodontic clinical outcomes were evaluated using the ABO Objective Grading System (cast-radiograph evaluation: C­R Eval). RESULTS: The mean total ABO C­R Eval score was 16 ± 9.1 in the labial appliance group and 12.7 ± 5.4 in lingual appliance group (p = 0.152). The mean total ABO-DI scores were 16.3 ± 7.3 and 15.4 ± 6.6 in the labial and lingual appliance groups, respectively (p = 0.445). A significant correlation was observed between the total DI and total C­R Eval scores. CONCLUSIONS: In this particular study and in the hands of two experienced orthodontists, no differences in the finishing quality of orthodontic treatments using the lingual technique or the buccal appliance technique were found. However, further prospective studies with larger sample sizes are necessary in order to generalize these results.