Virtual bracket removal: a comparative assessment of different software packages.

BACKGROUND: High precision intra-oral scans, coupled with advanced software, enable virtual bracket removal (VBR) from digital models. VBR allows the delivery of retainers and clear aligners promptly following debonding, thus reducing the patients' appointments and minimizing the likelihood of tooth movement. The objective of this study was to compare the enamel surface before bonding and after VBR using three different Computer-aided design (CAD) software and to compare their accuracy. METHODS: Maxillary scans of 20 participants starting orthodontic treatment were selected for inclusion in the study, who exhibited mild to moderate crowding and required bonding of brackets on the labial surface of permanent maxillary teeth (from the maxillary left first molar to the maxillary right first molar). Two intra-oral scans were conducted on the same day, before bonding and immediately after bonding using CEREC Omnicam (Sirona Dental Systems, Bensheim, Germany). The virtual removal of the brackets from the post-bonding models was performed using OrthoAnalyzer (3Shape, Copenhagen, Denmark), Meshmixer (Autodesk, San Rafael, Calif, USA), and EasyRx (LLC, Atlanta, GA, USA) software. The models that underwent VBR were superimposed on the pre-bonding models by Medit Link App (Medit, Seoul, South Korea) using surface-based registration. The changes in the enamel surface following VBR using the three software packages were quantified using the Medit Link App. RESULTS: There was a significant difference among the 3Shape, Meshmixer, and EasyRx software in tooth surface change following VBR. Specifically, EasyRx exhibited lower levels of accuracy compared to the other two VBR software programs (p<.001, p<.001). A significant difference in enamel surface change was observed between tooth segments across all software groups, in both incisors and molars, with VBR of the molars exhibiting the lowest level of accuracy (3Shape p=.002, Meshmixer p<.001, EasyRx p<.001). Regarding the direction of tooth surface changes following VBR, it was observed that all three groups exhibited a significant increase in the percentage of inadequate bracket removal across all teeth segments. CONCLUSIONS: 3Shape and Meshmixer manual VBR software were found to be more accurate than EasyRx automated software, however, the differences were minimal and clinically insignificant.

A Comparative Evaluation of Frictional Resistance of Various Lingual Brackets With Nitinol (NiTi) Archwires of Different Dimensions: An In Vitro Study.

Introduction Orthodontic mechanics involves transferring some of the applied force to the tooth's supporting components via friction, which in turn allows the tooth to move more easily. Aim The purpose of this in vitro experiment was to examine the frictional resistance (FR) of different lingual brackets utilizing Instron universal testing machines and nitinol (NiTi) archwires of varying sizes. Materials and methods Twenty-four sectional anterior die stones were replicated from a study model. They were categorized into eight categories, with the Libral lingual bracket and the JJ lingual bracket having 0.012" and 0.014" inch NiTi archwire, which were further subdivided into six subgroups. Three brackets were bonded to the anterior teeth of the upper and lower segments and replicated on other models with the help of silicon putty. Elastomeric modules were ligated to two diameters of NiTi wire (0.012" and 0.014") in each model. An Instron universal testing machine was used to measure the frictional force. Numerical data and descriptive statistics such as mean and standard deviation have been shown. Results In the overall analysis, it was observed that among JJ Orthodontics samples using 0.012" NiTi archwires, the maxilla exhibited a higher FR (4.205N) compared to the mandible (4.092N). Similarly, in the case of Libral Orthodontics samples with 0.012" NiTi archwires, the maxilla also demonstrated a higher FR (5.10N) than the mandible (4.97N). However, this trend did not hold for samples using 0.014" NiTi archwires. There was a statistically nonsignificant difference (p > 0.05) in the values between all the pairs of groups. Conclusion The present study concludes that Libral lingual brackets produced overall more FR than JJ lingual brackets.

Comparative Assessment of the Shear Bond Strength of Ceramic Brackets Bonded to the Enamel Surface with a Self-adhesive System.

Objectives: This study aimed to evaluate the shear bond strength of ceramic brackets bonded to the enamel surface using Vertise Flow, with or without the application of phosphoric acid. Materials and Methods: Forty-five extracted human premolar teeth were randomly assigned to three groups (N=15) based on the adhesive used for bonding: 1) Transbond XT, etch, and bond; 2) Vertise Flow; 3) Etch and Vertise Flow. After a 500-round thermocycling procedure, the shear bond strength was measured using a universal testing machine. The samples were then evaluated under a stereomicroscope to determine failure modes, and the Adhesive Remnant Index (ARI) was measured for each group. The data were analyzed with one-way ANOVA and post-hoc Tamhane at a significance level of P<0.05. Results: The highest shear bond strength values were observed in the Transbond XT (13.5±5.38MPa), acid etch and Vertise Flow (11.2±2.89MPa), and Vertise Flow (6.2±3.16MPa) groups, respectively, in descending order. The Vertise Flow group exhibited a significantly lower shear bond strength value compared to the other two groups, with no significant difference between the latter two. Conclusion: While all three study groups demonstrated clinically acceptable shear bond strength values, Vertise Flow showed lower values compared to the other two adhesives. The Vertise Flow composite resin system, whether used alone or with acid etching, remains a suitable choice for bonding ceramic brackets, offering the advantage of a simplified bonding procedure.

A digitalized analysis of incisal changes among orthodontically treated patients: A retrospective comparative study.

Background: To compare incisor angulation and/or position changes among orthodontically treated patients with metal brackets and clear aligners. Methods: A total of sixty-two participants of both sexes, aged-16-40 years old, with CL I skeletal pattern and mild crowding following strict eligibility criteria were included. The patients were divided into two groups based on their treatment approach. Pre and post lateral cephalograms were collected from Riyadh Elm University (REU) and then digitally analyzed using WEBCEPH (Medical Image Analysis) software. Eight angular and two linear measurements were used for the assessment. Results: The upper incisor angulation and position showed statistically significant differences when orthodontic clear aligners were used. In contrast, no significant difference was observed with the conventional orthodontic treatment. However, the upper incisal palatal root torque decreased after clear aligner therapy compared to conventional treatment. The inter-incisal angle demonstrated a significant increase with clear aligners compared to conventional treatment. Conclusions: The current study revealed the importance of definitive guidelines upon and after treatment, in addition to determining incisor changes. Orthodontic clear aligners are distinct from conventional treatments in controlling the incisors' angulation and position. The expansion treatment modality precedes Interproximal reduction in increasing the arch perimeter.

Shear bond strength of orthodontic brackets to single-shade composite surfaces: An in-vitro comparative study of different surface preparations.

PURPOSE: The primary objective of this study was to determine which single-shade composite surface yielded clinically acceptable shear bond strength (SBS) to metal orthodontics brackets. The secondary objectives were to identify the best composite surface treatment to enhance SBS and determine which surface treatment produced the least surface damage at debond. METHODS: Forty dental composite samples were selected from four different manufacturers (n=160) and grouped by manufacturer, one standard multi-shade dental system (FilTek™ Supreme Ultra) and three single-shade dental composites systems (OmniChroma®, SimpliShade™ and Venus® Diamond One). Each group of forty samples was randomly divided into four sub-groups (n=10). Each sub-group was identified by the surface treatment used, hydrofluoric acid (HFA), micro-etching (MIC), or phosphoric acid (PA). Shear bond strength testing and adhesive remnant index (ARI) were performed. Statistical analyses included Kruskal-Wallis, Wilcoxon rank-sum, and two-factorial ANOVA. RESULTS: OmniChroma® had statistically significant lower shear bond strength than the other composite materials tested. The control groups had statistically significant lower shear bond strength than Group 1/HFA (P<0.001) and Group 2/MIC (P<0.001). Group 1/HFA had the lowest distribution ARI score overall, while MIC had the highest ARI score distributions. CONCLUSIONS: The results of this in-vitro study found that all tested composite materials achieved clinically acceptable shear bond strengths. The utilization of micro-etching produced higher SBS. Significant Adhesive Remnant Index scores (< 0.001) were only found for OmniChroma® without any surface preparation.

Comparative in-vivo bond failure rate of orthodontic brackets when bracket base is treated with micro-abrasive blasting vs. acid etching: eighteen month randomized control trial and scanning electron microscope study.

Background: The aim of this study was threefold. Firstly, it aimed to introduce and detail a novel method for chemically etching the bases of stainless-steel orthodontic brackets. Secondly, the study sought to investigate the structural alterations within the brackets' microstructure following chemical etching compared to those with sandblasted bases, using electron microscopy analysis. Lastly, the study aimed to evaluate and compare the long-term durability and survivability of orthodontic brackets with chemically etched bases versus those with sandblasted bases, both bonded using the conventional acid etch technique with Transbond XT adhesive, over an 18-month follow-up period. Methods: The study was a randomized clinical control trial with triple blinding and split-mouth study design and consisted of two groups. The brackets in the sandblasted group were prepared by sandblasting the intaglio surface of the base of the bracket with 50 µm SiO2 particles. Hydrofluoric acid was used to roughen the base in the acid-etched group. The bases of the brackets were viewed under an electron microscope to analyze the topographical changes. Results: A total of 5,803 brackets (3,006 acid-etch, 2,797 sandblasted) in 310 patients were bonded, in a split-mouth design by the same operator. The patients were followed for 18 months. The failure rate of 2.59% and 2.7% was noted in an acid-etched and sandblasted group, respectively. There was a close approximation of curves in the Kaplan-Meier plot, and the survival distribution of the two groups in the log-rank (Mantel-Cox) test was insignificant; x2 = 0.062 (P value = 0.804). Conclusion: Acid etching if the bases of the brackets can be used as an alternative to sandblasting furthermore acid etching can be performed on the chair side.

The effect of orthodontic bracket base shape on shear bond strength to human enamel, an in vitro study.

The purpose of this study was to evaluate the in vitro effect of orthodontic bracket base shape on shear bond strength (SBS) to human enamel and assess the nature of debonding fractures using the Adhesive Remnant Index (ARI). Orthodontic brackets with different-shaped bases (flower, heart, rectangle) were bonded to 120 extracted human third molars. Shear bond strength was measured using a Servohydraulic Test System at 24 h and 2 months after bonding. Adhesive Remnant Index scores were evaluated under 10x magnification to assess the amount of resin left on the tooth. The control bracket (rectangular base shape) had the highest mean SBS (26.8 ± 8.2 megapascals [MPa]), and significantly differed from the flower (17.2 ± 4.4 MPa) and heart (18.9 ± 3.5 MPa) base shapes (p < 0.001). The mean SBS between debonding times at 24 h (21.5 ± 7.4 MPa) and 2 months (20.4 ± 6.7 MPa) were not statistically significant (p > 0.05). Analysis of ARI scores showed a significant difference between flower-24 h versus heart-2 months (p = 0.039), flower-24 h versus heart-24 h (p = 0.004), and control-2 months versus heart-24 h (p = 0.015). Bracket base shape influenced SBS, with the rectangular base shape having a higher mean SBS compared to flower and heart base shapes. Variations in ARI scores occurred based on bracket shape and were of a mixed adhesive-cohesive nature. All bracket shapes had bond strengths above the clinically acceptable range of 6-8 MPa, and may thus provide adequate SBS in a clinical situation.

Performance of two laser motion modes versus conventional orthodontic ceramic brackets debonding technique on enamel surface topography.

The risk of enamel deterioration that frequently coexists with debonding of orthodontic teeth brackets elevates the mandate for finding an optimum approach for debonding them without harmful effects. This in-vitro study is intended to compare the effects of two different laser modes (scanning and circular) and a conventional method on the enamel surface after debonding orthodontic brackets. 66 extracted premolars were assigned into 3 groups. After that, light-cure composite resin was used to attach the ceramic brackets to the teeth. Amongst the test groups, Group I: specimens that were debonded using conventional debonding using pliers; Group 2: specimens that were debonded using Er, Cr: YSGG laser applications using the circular motion method; and Group 3: specimens that were debonded using Er, Cr: YSGG laser applications using the scanning motion method. Adhesive Remnant Index (ARI) assessment, intra-pulpal temperature increase, enamel surface roughness after polishing, and assessment of the microstructure of enamel were carried out with scanning electron microscopy. The gathered information was examined statistically. The conventional debonding method had a significantly higher proportion of adhesive remnant index (ARI) scores of 2 and 3 in comparison to the circular (p < .004) and scanning laser groups (p < .001). There was no significant difference in ARI scores between the circular and scanning laser groups (p > .05). Moreover, the circular and scanning laser debonding methods resulted in a significantly higher proportion of Enamel Surface Roughness (ESR) scores of 0 and a lower proportion of ESR scores of 3 compared to the conventional technique group (p < .001). However, there was no significant difference in ESR scores between the circular and scanning laser methods (p = .945). Lastly, the average intra-pulpal temperature was significantly higher in the circular laser group (1.9 ± 0.5 ) compared to the scanning laser group (0.9 ± 0.2) with p < .001. Er, Cr: YSGG laser irradiation is a tool that shows promise for debonding ceramic brackets with minimal harm to the enamel surface. The scanning laser technique is more desirable due to the lower intra-pulpal temperature increase.

Evaluating the accuracy of one-piece and three-piece 3D-printed indirect bonding transfer trays: An in vitro study.

BACKGROUND: Recent developments in computer-aided design/computer-aided manufacturing (CAD/CAM) and 3D printing have enabled the fabrication of digital indirect bonding (IDB) transfer trays. These modern products require thorough investigation. OBJECTIVES: The aim of the study was to determine the accuracy of one-piece and three-piece IDB transfer trays in vitro. MATERIAL AND METHODS: An initial dental scan (IDS) of a randomly selected patient with digitally positioned brackets served as the master scan (MS) for designing 16 IDB transfer trays of each type. They were 3D printed and used for bonding 448 brackets to the models. Subsequently, the models were scanned with a TRIOS® 3 Intraoral Scanner (3Shape A/S, Copenhagen, Denmark), producing actual scans (ASs). The accuracy of bracket positioning was measured digitally on both MSs and ASs. The measurements were compared to the Objective Grading System for dental casts provided by the American Board of Orthodontics (ABO). RESULTS: The 2 types of IDB transfer trays showed comparable accuracy. All linear errors were within the clinically acceptable range, whereas the angular measurements demonstrated significant variability, resulting in clinically unacceptable transfer errors that ranged from 3.3% to 90.3%. CONCLUSIONS: The study results cannot be unconditionally extrapolated to other types of IDB transfer trays due to the diversity of their properties and features. The study evaluated the in vitro accuracy of IDB transfer trays. The revealed number of errors may be even higher in vivo due to limitations in visibility, salivary flow, interference from the tongue, and difficulties in achieving a proper fit of the IDB transfer tray to the teeth.

Comparative Evaluation of Shear Bond Strength, Enamel Microfracture, and Adhesive Remnant Index of APC Flash-Free System Versus Traditional Bonding: An In-Vitro Study.

INTRODUCTION: In orthodontics, shear bond strength plays an important role because it provides a good bond between the brackets and tooth surface; it avoids fracture of the tooth surface and prevents debonding of brackets from the tooth surface. All of these allow sufficient treatment time. Many factors, including the adhesive, its thickness, its strength, the bonding procedure, the clinician's ability, the base design, the geometry of the bracket, the material, and the kind of bracket all contribute to the shear bond strength. Brackets joined using conventional adhesive and adhesive pre-coated (APC) flash-free glue were the subjects of this comparison and evaluation research, which aimed to measure shear bond strength, enamel microfracture, and adhesive residual index. METHOD: 60 recently removed premolars from humans were used in this investigation. Before mounting on the acrylic block, the teeth were meticulously cleaned and preserved in artificial saliva. Two groups were formed from the collected premolars the control group and the experimental group. For the control group, we used American Orthodontics (AO) Master/Mini Master series brackets glued with resin composite kits. To make sure the adhesive was uniformly thick, we flashed extra adhesive around the brackets. In the meantime, samples were bonded using 3M Unitek APC flash-free technology in the experimental group. RESULTS: The research indicated that there was a statistically significant difference between the two groups to the adhesive remnant index (ARI) and mean shear bond strength. The shear bond strength of the experimental group averaged 10.96 megapascals (MPa), whereas the control group's was 5.70 MPa. The control group's ARI score was 2.97, whereas the experimental group's score was 2.4. There was no statistically significant change seen in enamel microfracture. CONCLUSION: A more robust shear bond may be possible using APC flash-free brackets. Compared to conventional bonding techniques and brackets, APC flash-free brackets have a lower adhesive residual index. The APC flash-free bracket technology also causes more enamel microfracture than conventional bonding and bracketing methods.

A longitudinal pilot study examining the influence of the orthodontic system chosen in adult patients (brackets versus aligners) on oral health-related quality of life and anxiety.

BACKGROUND: In recent years, the demand for orthodontic treatment with aligners has increased, led by patient need, as aligners typically provide them with improved aesthetics and less physical discomfort. In deciding with the patient on an appropriate orthodontic system, it is important to take into account the potential discomfort and the perceptions that patients have in relation to their treatment. The objective of this study was to analyze the influence of brackets or aligners on oral health-related quality of life (OHRQoL) and anxiety levels in a sample of adult patients during the first month of treatment. METHODS: The pilot study was carried out at the Dental Clinic of the University of Salamanca between November 2023 and February 2024. Eighty adult patients who initiated orthodontic treatment were selected and divided into two groups: the brackets group (Victory®; 3 M Unitek, California, USA) (n = 40) and the aligners group (Invisalign®; Align Technology, California, USA) (n = 40). OHRQoL was analyzed using the Oral Health Impact Profile-14 (OHIP-14) questionnaire, and anxiety was analyzed using the State-Trait Anxiety Inventory (STAI). The follow-up time was one month, with scores recorded at the beginning (T0) and one month after starting treatment (T1). RESULTS: The mean patient age was 33.70 (± 5.45) years old. The total sample (n = 80) consisted of 66.2% men and 33.8% women. In the brackets group, one month after starting treatment, the dimension with the highest impact was that of physical pain (5.62 ± 1.51). In the aligners group, where the dimension of psychological disability had the highest score (4.22 ± 1.02). In the brackets group the total OHIP score was higher at one month (T1) (33.98 ± 6.81) than at the start of treatment (T0) (21.80 ± 3.34); this greater impact on OHRQoL one month after starting treatment was not observed in the aligners group (T1 = 27.33 ± 6.83; T0 = 27.33 ± 6.22). The orthodontic system used did not influence participants' anxiety (p > 0.05). Age and sex were not influential factors in either OHRQoL or anxiety. CONCLUSIONS: The bracket system significantly influenced patients' OHRQoL. In the sample studied, no influence of the orthodontic system (brackets versus aligners) on anxiety was observed.

Effect of Different Primers on the Shear Bond Strength of Orthodontic Brackets Bonded to Reinforced Polyetheretherketone (PEEK) Substrate.

This in vitro study assessed the effect of different primers on the shear bond strength (SBS) and adhesive remnant index (ARI) of orthodontic brackets bonded to reinforced polyetheretherketone (PEEK) substrate. A total of 40 specimens were randomly distributed to two groups based on the primer used for orthodontic bonding: group 1 (control)-Transbond XT adhesive with Visio.link primer and group 2 (test)-orthodontic adhesive (Transbond XT) with traditional orthodontic primer. After bonding, specimens were thermocycled followed by SBS testing and ARI scoring of debonded specimens. Data were analyzed using the unpaired independent t-test and the Chi-square test. Group 1 specimens showed significantly higher SBS values (21.38 ± 1.48 MPa) compared to group 2 specimens (18.63 ± 1.29 MPa) (p < 0.0001). Adhesive remnant index scores showed no significant variations in bond failure modes and distributions between groups. The SBS obtained by the tested primers exceeded the clinically recommended value. Consequently, there is a comparable clinical application for both tested primers in orthodontic bonding, especially the traditional orthodontic primer, where the availability of Visio.link in clinical practice is not ensured.

An In Vitro Study to Compare the Shear Bond Strength of Metal and Ceramic Brackets Using Conventional Acid Etch and Self-Etch Primer.

Aim: In this, in vitro study's objective is to assess the shear bond strength (SBS) of metal and ceramic orthodontic brackets that have been adhered to enamel using a conventional acid etch/primer and self-etching primer (SEP) adhesive method. Materials and Methods: One hundred excised human premolars were bonded on brackets and were divided into group 1 -Metal brackets were bonded on teeth and group 2 -Ceramic brackets were bonded on teeth. These two groups were further subdivided: subgroup 1a - 25 metal brackets bonded using conventional acid etch/primer adhesive system, subgroup 1b - 25 metal brackets bonded using SEP, subgroup 2a - 25 ceramic brackets bonded using conventional acid etch/primer adhesive system, and subgroup 2b - 25 ceramic brackets bonded using SEP; brackets were debonded using a computerized Instron universal testing machine. Results: The mean value of SBS of metal and ceramic brackets bonded using conventional acid etch/primer adhesive systems had higher SBS than those bonded using SEP. SBS ranged from 7.95 to 12.24 MPa which was in the acceptable clinical range. Conclusion: SBS values of all four subgroups exceeded the range of 6-8 MPa observed to be acceptable for routine clinical use.

Evaluation of Antibacterial Effect of Hybrid Nano-coating of Stainless Steel Orthodontic Brackets on Streptococcus Mutans - An In vitro Study.

Nano-coating of orthodontic brackets with a combination or hybrid of metals and metal oxides may reduce the streptococcus mutans count and incidence of enamel decalcification seen around brackets in patients undergoing fixed orthodontic treatment. In total, 255 orthodontic brackets (3M Unitek, Monrovia, California, USA) were divided into one control group (group I) of 60 and three experimental groups of 65 each (groups II, III, and IV). The experimental group brackets were coated with a combination of silver-zinc oxide, copper oxide -zinc oxide, and silver-copper oxide nanoparticles using physical vapour deposition method. The two nanoparticles used for each group were mixed in the ratio of 1:1 by weight for providing a uniform hybrid coating. Sixty brackets from each group were used for microbiological evaluation of antibacterial activity against Streptococcus mutans in blood agar medium, and the remaining five brackets from each experimental group were used for SEM analysis to check the uniformity of the coating. Nano-coated brackets demonstrated better antibacterial properties than uncoated brackets. Copper oxide-zinc oxide nanoparticles coated brackets demonstrated better antibacterial properties than the silver-zinc oxide and silver- copper oxide coated brackets.

Reduction of surface treatment time by combination of citric acid and ascorbic acid while restoring shear bond strength of metal brackets bonded to bleached enamel: a pilot study.

BACKGROUND: To investigate the effect of a 50% ascorbic acid with 50% citric acid solution on the immediate shear bond strength (SBS) of metallic brackets after tooth bleaching. The enamel etching pattern and the required quantity of these combined acids as antioxidants following 35% hydrogen peroxide (HP) bleaching were also determined. METHODS: The stability of the solution at room temperature was assessed at various time intervals. Fifty teeth were randomly divided into five groups: non-bleached (G1), bleached then acid etched (G2), bleached followed by a 10-minute treatment with 10% sodium ascorbate and acid etched (G3), 5-minute treatment with 50% ascorbic acid (G4), and 5-minute treatment with a combination of 50% ascorbic acid and 50% citric acid (G5). Groups G2, G3, G4 and G5 were bleached by 35% HP gel for a total of 32 min. Acid etching in groups G1, G2, and G3 was performed using 37% phosphoric acid (Ormco®, Orange, CA, USA) for 15 s. In all groups, metal brackets were immediately bonded using Transbond™ XT primer and Transbond™ PLUS adhesive, with light curing for 40 s. The SBS was tested with a universal testing machine, and statistical analysis was conducted using one-way ANOVA followed by Tukey's HSD test. The level of significance was set at p < 0.05 for all statistical tests. RESULTS: Stability tests demonstrated that the combined acids remained effective for up to 21 days. Group G5 significantly increased the SBS of bleached teeth to the level of G1 (p < 0.05), while G3 did not achieve the same increase in SBS (p > 0.05). SEM analysis revealed enamel etching patterns similar to those of both control groups (G1 and G2). Kinetic studies at 6 min indicated that the antioxidation in G5 reacted 0.2 mmole lower than in G3 and G4. CONCLUSION: 5-minute application of the combined acids enhanced the SBS of bleached teeth comparable to unbleached teeth. The combined acids remain stable over two weeks, presenting a time-efficient, single-step solution for antioxidant application and enamel etching in orthodontic bracket bonding.

Evaluation of the surface characteristics and antibacterial properties of Titanium dioxide nanotube and methacryloyloxyethylphosphorylcholine (MPC) coated orthodontic brackets-a comparative invitro study.

OBJECTIVES: White spot lesions are the most common iatrogenic effect observed during orthodontic treatment. This study aimed to compare the surface characteristics and antibacterial action of uncoated and coated orthodontic brackets. MATERIALS AND METHODS: Sixty commercially available stainless steel brackets were coated with TiO2 nanotubes and methacryloyloxyethylphosphorylcholine. The sample was divided into Group 1: uncoated orthodontic brackets, Group 2: Stainless steel brackets with TiO2 nanotubes coating, Group 3: Stainless steel brackets with methacryloyloxyethylphosphorylcholine coating, and Group 4: Stainless steel brackets with TiO2 nanotubes combined with methacryloyloxyethylphosphorylcholine coating. Surface characterization was assessed using atomic force microscopy and scanning electron microscopy. Streptococcus mutans was selected to test the antibacterial ability of the orthodontic brackets, total bacterial adhesion and bacterial viability were assessed. The brackets were subjected to scanning electron microscopy to detect the presence of biofilm. RESULTS: The surface roughness was the greatest in Group 1 and least in Group 2 followed by Group 4 and Group 3 coated brackets. The optical density values were highest in Group 1 and lowest in Group 4. Comparison of colony counts revealed high counts in Group 1 and low counts in Group 4. A positive correlation between surface roughness and colony counts was obtained, however, was not statistically significant. CONCLUSIONS: The coated orthodontic brackets exhibited less surface roughness than the uncoated orthodontic brackets. Group 4 coated orthodontic brackets showed the best antibacterial properties. CLINICAL RELEVANCE: Coated orthodontic brackets prevent adhesion of streptococcus mutans and reduces plaque accumulation around the brackets thereby preventing formation of white spot lesions during orthodontic treatment.

Comparative characterization of supragingival plaque microbiomes in malocclusion adult female patients undergoing orthodontic treatment with removable aligners or fixed appliances: a descriptive cross-sectional study.

Objectives: This study aimed to explore the effects of removable aligners and fixed appliances on the supragingival bacterial communities in adult female patients undergoing orthodontic treatment. Methods: Supragingival plaque samples from 48 female individuals underwent microbiome analysis (16S rRNA gene sequencing) using PacBio Sequel sequencing. The study included 13 adults without orthodontic treatment needs as the control group (Group C), and 35 patients with comparable initial orthodontic conditions who received treatment at a university clinic in Beijing, China. The treatment involved either traditional fixed brackets (Group B, n = 17) or Invisalign® aligners (Group AT, n = 18). Bioinformatics methods were used for data analysis. Results: From the 48 plaque samples, a total of 334,961 valid reads were obtained, averaging 6,978 sequences per sample. The 16S rDNA sequences were classified into 25,727 amplicon sequence variants (ASVs). Significant variances in alpha and beta diversity among the groups were noted. Group B microbiome exhibited an increased presence of Gram-negative bacteria. At the phylum level, Actinobacteriota was significantly more prevalent in Group C samples, while Bacteroidota was enriched in Group B samples. Family-level relative abundance analysis showed a notable increase in Saccharibacteria (formerly TM7) and Prevotellaceae in Group B. Genus-level analysis revealed a significant rise in Lautropia in Group AT. Fixed orthodontic appliances were linked to oral microbiome changes, notably an enhanced relative abundance of anaerobes, including periodontal pathogens. Conclusion: The observation points to the impact of orthodontic appliance on the oral microbial community, highlighting the difference between traditional braces (Group B) and clear aligners (Group AT)in terms of the predominance of anaerobic and gram negative bacteria. This emphasizes the importance of considering the microbiological effects when choosing orthodontic appliance and underscores the need for tailored oral hygiene practices for individuals undergoing these treatments. This research might provide insights that could assist in the development of innovative cleaning techniques and antibacterial materials.

Structural and Color Alterations of Teeth following Orthodontic Debonding: A Systematic Review.

AIM: The objective of this study was to explore the effects of fixed orthodontic appliances on enamel structure by assessing microfractures, surface roughness, and alterations in color. METHODS: This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A systematic search of online databases was conducted using the keywords 'enamel' AND 'orthodontic debonding'. Eligibility criteria included both in vivo and ex vivo clinical trials conducted on human teeth. RESULTS AND DISCUSSION: A total of 14 relevant papers were analyzed. Various instruments and techniques were utilized across different studies to assess surface roughness, color change, and surface fractures. CONCLUSIONS: The findings of this study suggest that ceramic brackets may lead to an increase in enamel fractures, particularly during bracket removal. The surface roughness of enamel exhibits variability depending on the adhesive substance and polishing methods used post-removal. Fixed orthodontic appliances could induce changes in enamel color, which may be alleviated by the use of nano-hydroxyapatite or specific polishing techniques. Further research is necessary to identify effective strategies for managing these color changes and improving the overall outcomes of fixed orthodontic treatment.

Temperature Changes in the Pulp Chamber During Orthodontic Bonding Using a High-Power Light-Emitting Diode Device With Two Different Exposure Times and Intensities: An In-Vitro Study.

OBJECTIVE: This study used a high-power light-emitting diode (LED) device to evaluate the effects of two exposure times and intensities on pulp chamber temperature and cooling time during bracket bonding. MATERIALS AND METHODS: Sixty upper premolars were used in the sample in this study. These premolars were split into two main groups based on the exposure time and intensity: the first group employed a traditional curing mode (TCG) for 20 seconds with an intensity of 1200 mw/cm2, whereas the second group had a quick curing mode (QCG) for 3 seconds with an intensity of 2500 mw/cm2. The pulp chamber's temperature variations and cooling times were recorded using a thermal imaging camera. The Mann-Whitney U test was used to find differences between the two-group comparison of the pulp chamber's temperature and cooling time. RESULTS: The two groups had statistically significant differences regarding the temperature increase in the pulp chamber and cooling time (p > 0.001). The mean temperature increase in the traditional curing group was 3.52°C, which is greater than that in the quick curing group (i.e., a mean value of 1.28°C). The mean cooling time in the traditional curing group was 38.83 seconds, which is greater than that in the quick curing group (9.97 seconds). CONCLUSIONS: Reducing the exposure time to 3 seconds and increasing the intensity to 2500 mw/cm2 is considered safer for the pulp chamber during and after the curing process.

Effect of Elastomeric Module Degradation and Ligation Methods on Kinetic Friction between NiTi or Stainless Steel Wires and Stainless Steel Brackets.

Objectives: The reduction of resistance to sliding between the archwire and bracket promotes more seamless tooth movement, leading to a faster and improved orthodontic treatment experience. This research aimed to examine how the degradation of elastomeric modules, different ligation methods, bracket-wire angle, and wire type (nickel titanium, NiTi or stainless-steel, SS) impact the kinetic friction resulting from the interaction between NiTi or SS archwires and SS brackets. Materials and Methods: The current in vitro study was conducted on nine groups, including NiTi and SS archwires with three types of ligations (O-ring, figure of 8, and SS wire ligature) and two bracket-wire angles (0˚ and 10˚). The kinetic friction in each group was measured using a Universal Testing Machine at four time intervals: baseline, day one, week one, and week four. Repeated measures ANOVA, Mauchly test of sphericity followed by the Greenhouse-Geisser test, and relevant post hoc tests were used for statistical analysis (P<0.05). Results: The authors found a decrease in kinetic friction in all types of ligations, which confirmed the effect of time on the degradation of ligation modules. The kinetic friction of figure of 8 ligations was higher than both O-ring and SS wire ligations. No difference was observed between O-ring and SS wire ligations. Furthermore, the bracket-wire angle did not affect friction. Conclusion: The authors suggest that the use of figure of 8 ligations in NiTi and SS wires should be limited due to their high friction and replaced with other types of ligations, if possible.