Orthodontic Brackets Research Articles

Compressive Strength Comparison of Different Orthodontic Metal Bracket Systems

Rebonding of orthodontic brackets to new positions during treatment with fixed orthodontic appliances is a common practice and it is important not to cause plastic deformation during bracket removal. The aim of this study was to evaluate the resistance of various brackets to compression and assess their thresholds for plastic deformation. 5 different groups of metal brackets (BioQuick, Damon Q, Experience, Mini Diamond, Mini Sprint II) were bonded to 85 extracted human central incisor teeth utilizing the same adhesive system (Transbond XT). Compressive forces were applied via Weingart forceps in order to mimic clinical setting with the Shimadzu Universal tester. Kruskall-Wallis and Mann-Whitney U tests were used for comparing groups. Damon Q group exhibited the highest yield point value (549.35 N), the highest ultimate strength value (764.50 N) and the highest failure/debonding point value (721.89 N). The lowest yield point value (211.73 N), the lowest ultimate strength value (224.07 N) and the lowest failure/debonding point value (121.71 N) were found in the Mini Diamond group. The ultimate strength point values of Damon Q and Experience brackets were higher compared to Mini Diamond, BioQuick and Mini Sprint II brackets (p < 0.05). No statistically significant difference between Damon Q and Experience brackets in terms of yield strength and ultimate strength values (p > 0.05) were observed. Adhesive Remnant Index (ARI) score was 3 for all debonded samples. It may be concluded that Damon Q brackets were more resistant to plastic deformation than Mini Diamond, BioQuick and Mini Sprint II brackets (p < 0.05).

Effects of Thermocycling with Two Different Curing Techniques on Enamel Micro-Cracks Formation, Debonding, and Failure Modes of Ceramic Brackets: An In Vitro Study.

Despite the rise in popularity of ceramic braces for adults, the risk of enamel microcracks (EMCs) upon removal remains a significant drawback for both dental professionals and patients. Our study aimed to assess the effects of thermocycling, pre-curing, and co-curing techniques with different bonding agents on the enamel surface of teeth after the removal of ceramic brackets. We also examined the incidence, quantity, length, and direction of EMCs on tooth surfaces. Additionally, the adhesive remnant index (ARI) scores and orthodontic bracket bond failure modes were evaluated and compared. The study divided 40 extracted upper canine teeth into ten groups for further analysis. Two groups had intact enamel as the negative control, while the remaining groups had orthodontic ceramic brackets bonded using different bonding agents and curing techniques. Thermocycling was performed in five groups, and ARI was assessed after debonding. The study findings were statistically significant (p < 0.05) in demonstrating the impact of curing techniques on EMCs and debonding outcomes. Seventh-generation bonding agents resulted in complete adhesive removal (ARI = 0). The microcracks' incidence, number, and length showed insignificant results. Differences in ARI between thermocycler and non-thermocycler samples were insignificant. Both co-curing and pre-curing techniques yielded comparable ARI results. This study highlights the importance of using advanced bonding agents to minimize enamel damage during ceramic bracket debonding.

Expression of artefacts from different orthodontic brackets and wires in cone beam computed tomography scans-an in vitro study.

To investigate artefacts produced by different orthodontic brackets and wires in cone-beam computed tomography (CBCT) scans. Two dental arches were made using extracted human teeth and plaster. Three pairs of acetate plates containing different brackets - metallic, ceramic, and self-ligating ceramic with NiTi clip - along with a control plate (i.e., without brackets) were prepared. Wire changes (NiTi and steel) were made during CBCT acquisitions, performed with a fixed exposure protocol. Axial slices were selected for mean gray values and standard deviation measurement in three regions of interest (buccal, lingual, and tooth). Noise and contrast-to-noise ratio (CNR) were calculated and compared among the different brackets and wires by ANOVA with a significance level of 5%. Overall, the buccal and tooth region were mostly affected by the metallic and self-ligating brackets, showing higher noise, and lower CNR (p < 0.05). On the other hand, less impact of ceramic brackets in the image quality was observed (p ≥ 0.05). The lingual region did not show expressive differences among the brackets and wire combinations (p ≥ 0.05). The presence of wire associated with the brackets did not worsen image quality (p ≥ 0.05). In conclusion, metallic and self-ligating brackets have greater artefact expression than ceramic brackets. The wire did not influence image quality. One should pay attention to the type of brackets when requesting a CBCT scan during treatment, as metallic and self-ligating brackets may express greater artefacts than ceramic brackets.

DNA fragmentation of lymphocytes and sperm cells induced by nickel released from orthodontic archwires: A preliminary study.

Orthodontic brackets and archwires placed intraorally are subject to corrosion, leading to the release of cytotoxic metal ions. The aim of this study was to determine whether the use of orthodontic NiTi archwires increases systemic Ni levels and cause alterations on the DNA of cells unrelated to the oral environment such as lymphocytes and sperm cells. Human urine, semen and blood samples were collected before (baseline) sham placement of orthodontic archwires and 15 and 30 days after placement. Lymphocytes and sperm cells cells were evaluated by comet assay. Ni concentration levels in urine increased significantly between baseline and 15 days (p<0.01) and 15 and 30 days of exposure (p<0.01). Progressive decrease in sperm viability and motility was observed between the sampling periods. Lymphocytes and sperm cells showed DNA fragmentation. The increase in systemic concentration of nickel induced structural damage in the DNA of lymphocytes and human sperm cells.

Biomechanical innovations in correcting severe malocclusions

The correction of severe malocclusions presents significant challenges in orthodontics due to the complexity and precision required for effective treatment. Recent biomechanical innovations have transformed the landscape of orthodontic care, offering more precise, efficient, and patient-friendly solutions. Advancements in orthodontic bracket systems, including the development of self-ligating brackets and heat-activated arch wires, have enhanced the control and comfort of tooth movements, reduced treatment times and improving patient outcomes. Temporary anchorage devices (TADs) have provided stable anchorage points, enabling complex tooth movements that were previously difficult to achieve. TADs have proven particularly effective in managing open bites and class II malocclusions, offering non-surgical alternatives for severe cases. The integration of digital technology in orthodontics, such as 3D imaging and computer-aided design/manufacturing (CAD/CAM), has further revolutionized treatment planning and execution. These technologies facilitate accurate diagnostics and the creation of customized orthodontic appliances, ensuring precise and predictable treatment outcomes. Clear aligner therapy, initially limited to simple cases, has advanced through the use of improved thermoplastic materials and digital customization, allowing for the treatment of more complex malocclusions. Innovative force application techniques, including the use of attachments and elastics, have expanded the capabilities of aligners, making them a versatile and effective alternative to traditional braces. Collectively, these biomechanical innovations have significantly improved the management of severe malocclusions, enhancing treatment efficiency, precision, and patient comfort. The ongoing development of these technologies promises to further advance the field of orthodontics, providing more effective and aesthetically pleasing solutions for patients with complex dental alignment issues.

Effect of using 445 nm diode laser with different curing time on enamel shear bond strength of resin composite used for bonding orthodontic brackets. An in-vitro study

Effect of using 445 nm diode laser with different curing time on enamel shear bond strength of resin composite used for bonding orthodontic brackets. An in-vitro study

The effect of antimicrobial peptide-added adhesive resins on shear bond strength and the adhesive remnant index of orthodontic brackets

ObjectivesThe aim of this study was to evaluate the effect of in-vivo produced Nisin which is an antimicrobial peptide (AMP) added to adhesive resin on shear bond strength (SBS) and the adhesive remnant index (ARI) of orthodontic brackets.MethodsBacterial AMP was produced by fermentation and the ideal AMP/Bond concentration and antimicrobial efficacy of the mixture were tested. To evaluate the SBS and ARI scores of AMP-added adhesive resins, 80 maxillary premolar teeth extracted for orthodontic purposes were used and randomly assigned into 2 groups (n = 40). Group 1: Control Group (teeth bonded with standard adhesive resin); Group 2: Experimental Group (teeth bonded with AMP-added adhesive resin). Statistical analysis was performed using the SPSS package program and applying the Mann-Whitney U and Fisher’s exact tests. P < 0.05 was considered as statistically significant.ResultsNisin synthesized in-vivo from Lactococcus lactis (L. lactis) (ATCC 7962) bacteria was provided to form a homogenous solution at an ideal concentration To find the minimum AMP/Bond mixture ratio that showed maximum antimicrobial activity, AMP and Bond mixtures were tested at various concentration levels between 1/160 and 1/2 (AMP/Bond). As a result, the optimum ratio was determined as 1/40. The antimicrobial efficacy of Nisin-added adhesive resin was tested against Streptococcus mutans (S. mutans) (ATCC 35,688) and Lactobacillus strains (cariogenic microorganisms). AMP formed a 2.7 cm diameter zone alone, while 1/40 AMP-bond mixture formed a 1.2 cm diameter zone. SBS values of the teeth bonded with Nisin added adhesive (17.49 ± 5.31) were significantly higher than the control group (14.54 ± 4.96) (P = 0.004). According to the four point scale, Nisin added adhesive provided a higher ARI score in favour of the adhesive and tooth compared to the control group (ARI = 3, n = 20).ConclusionsNisin produced from L. lactis (ATCC 7962) had greater antimicrobial effects after mixing with adhesive bond against cariogenic microorganisms S. mutans (ATCC 35,688) and Lactobacillus strains. Nisin added adhesive increased shear bond strength (SBS) of orthodontic brackets and ARI scores in favor of adhesive & teeth.Clinical relevanceClinicians should take into account that using Nisin-added adhesive resin in orthodontic treatments can provide prophylaxis against tooth decay, especially in patients with poor oral hygiene.

Pretreatment of enamel with Riboflavin activated photodynamic therapy and Er, Cr: YSGG laser for bonding of orthodontic bracket with adhesive modified with cerium oxide nanoparticles

AimTo assess the degree of conversion (DC) and shear bond strength (SBS) of experimental adhesive (EA) infused with and without 1 % Cerium oxide (CeO₂)-NPs on metallic bracket bonded to enamel conditioned with three different pretreatment regimes PDT-activated (Riboflavin) RF, ECY (Er, Cr: YSGG), and Phosphoric acid (PA). Material and MethodEA and EA modified with 1 % CeO₂-NPs were prepared. Characterization of CeO2NPs was assessed using a scanning electron microscope (SEM). Seventy-two premolars extracted due to periodontal or orthodontic reasons were disinfected. Samples were mounted and allocated into three groups according to enamel surface treatment before bracket bonding. Samples in Group 1 were pretreated with Traditional 37 % PA-gel; Specimens in Group 2 surface treated with RF-activated PDT, and samples in Group 3 were conditioned using ECY. Brackets were placed on conditioned surfaces and samples were aged and underwent SBS testing using UTM. ARI index was used to assess bond failure. DC was evaluated for both adhesives using FTIR. ANOVA and Tukey post hoc test were used to compare the means and standard deviation (SD) of SBS and DC in different experimental groups. ResultsEnamel conditioned with PA and RF activated by PDT demonstrated comparable bond values with 1 % CeO2 infused in EA and EA (p>0.05).ARI analysis shows that enamel conditioned with PA and RF activated by PDT showed the majority of failure types between 1 and 2 irrespective of the type of adhesive. DC value in EA (73.28±8.37) was the highest and comparable to 1 % CeO2 infused in EA (66.48±6.81) ConclusionRF-activated PDT can be used alternatively to 37 % PA for enamel conditioning when bonding metallic brackets. Infiltration of 1 % CeO2 NPs in EA improves SBS irrespective of the type of enamel conditioning. Infusion of 1 % CeO2 NPs in EA demonstrates no significant difference in DC compared to EA.

Convolutional neural network for automated tooth segmentation on intraoral scans

BackgroundTooth segmentation on intraoral scanned (IOS) data is a prerequisite for clinical applications in digital workflows. Current state-of-the-art methods lack the robustness to handle variability in dental conditions. This study aims to propose and evaluate the performance of a convolutional neural network (CNN) model for automatic tooth segmentation on IOS images.MethodsA dataset of 761 IOS images (380 upper jaws, 381 lower jaws) was acquired using an intraoral scanner. The inclusion criteria included a full set of permanent teeth, teeth with orthodontic brackets, and partially edentulous dentition. A multi-step 3D U-Net pipeline was designed for automated tooth segmentation on IOS images. The model’s performance was assessed in terms of time and accuracy. Additionally, the model was deployed on an online cloud-based platform, where a separate subsample of 18 IOS images was used to test the clinical applicability of the model by comparing three modes of segmentation: automated artificial intelligence-driven (A-AI), refined (R-AI), and semi-automatic (SA) segmentation.ResultsThe average time for automated segmentation was 31.7 ± 8.1 s per jaw. The CNN model achieved an Intersection over Union (IoU) score of 91%, with the full set of teeth achieving the highest performance and the partially edentulous group scoring the lowest. In terms of clinical applicability, SA took an average of 860.4 s per case, whereas R-AI showed a 2.6-fold decrease in time (328.5 s). Furthermore, R-AI offered higher performance and reliability compared to SA, regardless of the dentition group.ConclusionsThe 3D U-Net pipeline was accurate, efficient, and consistent for automatic tooth segmentation on IOS images. The online cloud-based platform could serve as a viable alternative for IOS segmentation.

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<.001) and Group 2/MIC (p<.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.

Shear bond strength and adhesive remnant index evaluation of three different orthodontic adhesive systems using three different light curing times

BackgroundSuccess of long orthodontic treatment using orthodontic brackets depends mainly on the efficiency of the adhesive system used and it's degree of resistance in the face of stresses and foresees applied during treatment. The aim of this study was to evaluate the shear bond strength of orthodontic brackets bonded with three adhesive systems using different light curing times. Materials and methodsThe 126 human extracted premolars were randomly divided into three equal groups (n = 42) depending on the type of adhesive system used; total-etch (Transbond XT), self-etch (Transbond Plus), and self-adhesive (GC-Ortho Connect) system. Then each group was randomly subdivided into three subgroups (n = 14) based on the curing time; 1-s, 3-s, and 20-s. The shear bond strength (SBS) and adhesive remnant index (ARI) were evaluated in each subgroup using universal testing machine and stereomicroscope respectively. The data were analyzed statistically by a two-way ANOVA for SBS, and Scheirer Ray Hare Test for ARI. The significance level was set at P ≤ 0.05. ResultsThe results showed a statistically significant difference in shear bond strength at the three-time points for each adhesive system (p < 0.001) with the highest SBS value in 20-sec groups followed by 3-sec groups while 1-sec groups was the lowest. However, there was no statistically significant difference in Shear bond strength between the three adhesive systems except 20-sec groups (p < 0.001). ARI showed a statistically significant difference between all adhesive systems with the highest scores in TE groups, while the lowest in SE groups. ConclusionAll adhesive systems provided acceptable values of SBS at all curing times except the 1-sec group in SE and SA adhesive systems where the SBS values were the lowest and below the acceptable range.

Tooth Autotransplantation, Autogenous Dentin Graft, and Growth Factors Application: A Method for Preserving the Alveolar Ridge in Cases of Severe Infraocclusion-A Case Report and Literature Review.

Background: Tooth infraocclusion is a process in which a completely or partially erupted tooth gradually moves away from the occlusal plane. Submerged teeth can lead to serious complications. Treating teeth with infraocclusion is very challenging. One of the procedures allowing for the replacement of a missing tooth is autotransplantation. The aim of this paper is to review the literature on teeth autotransplantation, supported by a case report involving the autotransplantation of a third mandibular molar into the site of an extracted infraoccluded first mandibular molar, as well as the utilization of advanced platelet-rich fibrin (A-PRF) alongside autogenous dentin grafts for bone tissue regeneration. Methods: A severely infraoccluded first permanent right mandibular molar was extracted and then ground to obtain the dentin graft. A-PRF clots (collected from the patient's peripheral blood) were added to the autogenous dentin graft, to create the A-PRF membrane. An atraumatic extraction of the lower left third molar was performed and then it was transplanted into the socket of tooth no. 46. Immediately after transplantation, tooth no. 38 was stabilized with orthodontic bracket splints for 3 months. The patient attended regular follow-up visits within 12 months. Results: After one year, the patient did not report any pain. In the clinical examination, the tooth and surrounding tissues did not show any signs of infection. However, radiographically, cervical inflammatory resorption, unchanged pulp canal dimensions, absent root growth, periapical radiolucency, and lack of apical and marginal healing were observed. Reconstruction of the bone defect was obtained and the alveolar ridge of the mandible was preserved. Due to poor stability of the tooth and severe resorption, the tooth needed to be extracted. Conclusions: This study is designed to critically evaluate the efficacy of autotransplantation, the application of growth factors, and the integration of autogenous dentin grafts in remedying dental deficiencies resulting from reinclusion. We aim to point out the possible causes of treatment failure.

Effect of Chlorhexidine and Povidone-iodine Mouth Rinses on Corrosion Resistance and Surface Characteristics of Stainless Steel Orthodontic Brackets - An in vitro and in vivo Study.

Stainless steel (SS) orthodontic brackets may have varying corrosion resistance when used with mouthwashes during orthodontic treatment. Studying their effects on orthodontic brackets will be beneficial. The study's objective was to analyze the surface characteristics of SS orthodontic brackets and their resistance to corrosion, exposed to chlorhexidine and povidone-iodine mouth rinses - an in vitro and in vivo study. The in vitro test: MBT 0.022" slot SS orthodontic brackets were immersed in three groups - Group A - Modified Meyer-Fusayama artificial saliva (AS), Group B - Chlorhexidine, and Group C - Povidone-iodine mouthwash. The in vivo test: Brackets were conventionally bonded on the patient's teeth and divided into Group I - control group, Group II - patients used chlorhexidine, and Group III used povidone-iodine mouth rinse. The corrosion resistance and surface characteristics of SS brackets were determined using scanning electron microscope (SEM), electrochemical impedance spectroscopy, and X-ray photoelectron spectroscopy. Higher corrosion resistance was obtained for brackets immersed in chlorhexidine mouth rinse. The polarization resistance value of the orthodontic SS bracket was 109 MΩ, 1383 MΩ, and 769 MΩ immersed in AS, chlorhexidine, and povidone-iodine mouth rinse, respectively. After surface chemical analysis, XPS data showed the largest intensity peak of metallic chromium (CrO) fresh sample and in the sample immersed in chlorhexidine mouthwash. According to SEM, brackets immersed in chlorhexidine showed a relatively smooth surface. In this study, chlorhexidine was found to be less corrosive followed by povidone-iodine.

Effect of oil pulling on the Streptococcus mutans concentation in plaque around orthodontic brackets -A prospective clinical study.

Fixed orthodontic appliances create areas of plaque stagnation leading to an increase in the volume, structure, and composition of plaque. This increases the chances of decalcification and white spot lesions. Oil pulling, an ancient practice involving swishing oil in the mouth, has demonstrated a significant reduction in plaque scores after 45 days, and a reduction in salivary Streptococcus mutans concentration in few studies done in nonorthodontic subjects. The aim was to compare the concentration of S. mutans in plaque around orthodontic brackets in patients using oil pulling with sesame oil and those on routine oral hygiene. Twenty subjects requiring fixed orthodontic treatment were divided into two equal groups: Group A-Oil pulling and Group B-Control. All subjects were instructed to follow common oral hygiene methods and in addition, Group A was instructed to perform oil pulling for 30 days starting 1 month after placement of fixed appliances. Plaque specimens were collected from labial surfaces of maxillary lateral incisors and quantification of S. mutans was done using real-time polymerase chain reaction. Mean and standard deviations for descriptive statistics, paired, and unpaired sample t-tests were analyzed. Comparison of S. mutans concentration between T1 and T2 demonstrated a significant difference in both control and study groups. The experimental group showed significantly lesser S. mutans concentration compared to the control group. Oil-pulling therapy with sesame oil resulted in a statistically significant reduction in the concentration of S. mutans in the plaque around orthodontic brackets.

Evaluation of Prevention of Initial Enamel Lesions around Orthodontic Brackets by Using Different Remineralizing Agents: An Original Research

ABSTRACT Objective: The purpose of this study was to compare the efficacy of various remineralizing agents in stopping the early enamel lesions surrounding orthodontic brackets from progressing. Techniques: Four groups were randomly allocated to a total of 100 participants: the control group (no treatment), calcium phosphate, casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), and fluoride varnish. Remineralizing chemicals were administered in accordance with manufacturer recommendations, and enamel lesions were created around orthodontic brackets. At baseline and follow-up visits, enamel lesion development was evaluated by visual inspection, quantitative light-induced fluorescence, and microhardness tests. Results: All treatment groups showed significant improvements in microhardness and decreases in lesion size compared to the control group (P &lt; 0.05). Of all the treatment groups, CPP-ACP showed the most notable improvement in microhardness. Regarding the reduction of lesion size, there were no notable variations between the therapy groups (P &gt; 0.05). Conclusion: Initial enamel lesions surrounding orthodontic brackets can be effectively prevented from progressing with the use of fluoride varnish, calcium phosphate, and CPP-ACP. Promising improvements in microhardness indicate that CPP-ACP may be a better treatment choice. Larger sample sizes and longer follow-up times are needed for future studies to validate these results and clarify the best strategy for maintaining the health of enamel throughout orthodontic treatment.

Comparative evaluation of shear bond strength of orthodontic brackets bonded with two self-etching adhesive systems: an in vitro study

Abstract Objective To evaluate and compare the shear bond strength (SBS of the new Optibond eXTRa Universal and Adper Prompt L-Pop self-etch adhesive systems using an in vitro experimental design. Patients and methods The sample included 40 freshly extracted human maxillary first premolars collected from orthodontic patients, adhering to ethical guidelines. The teeth were randomly assigned to two groups, one treated with Optibond eXTRa Universal self-etch adhesive and the other with Adper Prompt L-Pop. Stainless-steel brackets were then bonded to the teeth using BracePaste orthodontic adhesive composite resin. After storage and thermocycling, SBS was measured using a universal testing machine, and adhesive remnant index (ARI) scores were assessed under a digital microscope. Statistical analyses were performed, including the Shapiro–Wilk method, Student’s t-test for SBS, and χ 2 test for ARI scores. Results The mean SBS showed no significant difference between both groups (P = 0.076). However, the distribution of ARI scores exhibited a highly significant difference between the two groups (P &lt; 0.001). Conclusion While both adhesives exhibited similar bond strengths, variations in adhesive residue patterns highlight the importance of considering adhesive performance in orthodontic applications such as ease of cleanup and potential impact on enamel health.

Effect of Different Conditioning Methods on Shear Bond Strength of Orthodontic Ceramic Brackets Bonded to Porcelain Ceramic Surface

The study aimed to investigate the shear bond strength (SBS) of orthodontic ceramic brackets bonded to porcelain ceramic surfaces that had undergone various conditioning methods. Materials and Methods: Forty ceramic discs were fabricated (vita vmk master®, zahnfabric, Germany) with a diameter of (4*10mm). Ceramic discs were divided into four groups (n = 10) according to ceramic surface conditioning methods, 37% phosphoric acid (PH), 9%hydrofluoric acid (HF), and surface conditioning with a fine diamond bur. Transbond XT light-cure composite was used to bond ceramic brackets. Before bonding, extra samples from each group were chosen to be examined using a scanning electron microscope (SEM) to determine the topography of the ceramic surface. The Shear Bond Strength data were evaluated using one-way analysis of variance (ANOVA) and Tukey HSD tests. Under an optical stereomicroscope, debond surfaces were examined. Results: Surface conditioning with a fine diamond bur + HF acid etching group produced the highest SBS (30.64 ± 7.28 MPa), and the lowest SBS was investigated in the PH acid etching group (14.75 ±3.32 MPa). Conclusions: Different conditioning methods affected the porcelain ceramic surface's shear bond strength (P &lt; 0.05). The highest SBS was found in the fine diamond bur_+ HF acid etching group; however, this had a deleterious effect on the ceramic surface after debonding.

Synthesis and Characterization of a Sustained Nitric Oxide-Releasing Orthodontic Elastomeric Chain for Antimicrobial Action.

The acidic byproducts of bacteria in plaque around orthodontic brackets contribute to white spot lesion (WSL) formation. Nitric oxide (NO) has antibacterial properties, hindering biofilm formation and inhibiting the growth of oral microbes. Materials that mimic NO release could prevent oral bacteria-related pathologies. This study aims to integrate S-nitroso-acetylpenicillamine (SNAP), a promising NO donor, into orthodontic elastomeric ligatures, apply an additional polymer coating, and evaluate the NO-release kinetics and antimicrobial activity against Streptococus mutans. SNAP was added to clear elastomeric chains (8 loops, 23 mm long) at three concentrations (50, 75, 100 mg/mL, and a control). Chains were then coated, via electrospinning, with additional polymer (Elastollan®) to aid in extending the NO release. NO flux was measured daily for 30 days. Samples with 75 mg/mL SNAP + Elastollan® were tested against S. mutans for inhibition of biofilm formation on and around the chain. SNAP was successfully integrated into ligatures at each concentration. Only the 75 mg/mL SNAP chains maintained their elasticity. After polymer coating, samples exhibited a significant burst of NO on the first day, exceeding the machine's reading capacity, which gradually decreased over 29 days. Ligatures also inhibited S. mutans growth and biofilm formation. Future research will assess their mechanical properties and cytotoxicity. This study presents a novel strategy to address white spot lesion (WSL) formation and bacterial-related pathologies by utilizing nitric oxide-releasing materials. Manufactured chains with antimicrobial properties provide a promising solution for orthodontic challenges, showing significant potential for academic-industrial collaboration and commercial viability.

The effect of Fluoride varnish and Silver Diamine Fluoride in prevention of enamel demineralization around orthodontic bracket through UV illumination: An in vitro study

Brief Background The present in vitro study evaluated the effectiveness of Fluoride Vanish and Silver Diamine Fluoride in preventing enamel demineralization around orthodontic brackets, using a UV light on a group of extracted teeth with bonded brackets. Materials and Methods In this study, 30 samples of extracted human permanent teeth with bonded orthodontic brackets were separated into control group I (no fluoride varnish), experimental group II (fluoride varnish was applied), and experimental group III (fluoride varnish with SDF) to examine the preventive effects of fluoride on enamel demineralization. Teeth were subjected to three demineralization cycles in a standard demineralization solution. Enamel demineralization was measured according to the index of Gorelick et al. in all three groups at baseline, after the first and second demineralization cycles under UV light. Results Statistically significant differences were observed between the control group and the FV group after the first demineralization cycle. (p value&lt; 0.0001) No significant difference was found between baseline readings and after two demineralization cycles in the FV+SDF group. Summary and conclusion Fluoride varnish, along with SDF, is effective in reducing enamel demineralization. During the bonding appointment, the initial application of fluoride varnish around the orthodontic bracket can offer significant protection against white spot lesions (WSL). The development of WSL next to brackets can be avoided with regular professional applications of an FV during treatment with fixed orthodontic appliances. Key Words Enamel Demineralization; Fluoride Varnish; Orthodontic Brackets; Silver Diamine Fluoride.

Rebonding of orthodontic metallic brackets: Comparative analysis of shear bond strength using different sandblasting particles

IntroductionThis study aimed to evaluate the effect of two different sandblasting particles on the shear bond strength of rebonded metallic brackets to dental enamel. MethodsForty-eight metallic orthodontic brackets were divided into 4 experimental groups (n = 12) according to the surface treatment they received at their bases: positive control group (Metal), negative control group (MetalU), sandblasted with Rocatec Soft (MetalRoc) and sandblasted with Glass beads (MetalGlas). An elementary and topographic analysis of the base of the brackets was performed using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) after the surface treatment. The brackets rebonded to dental enamel were tested for their shear bond strength. The obtained data were subjected to statistical analysis one-way ANOVA and Tukey's test (α = 0.05). The fracture surfaces of the specimens after the mechanical test were analyzed using optical microscopy to classify the failure mode. ResultsSEM photomicrographs for the MetalRoc and MetalGlas groups showed efficient removal of the remaining resin composite. In both sandblasting treatments, the presence of silicon (Si) and oxygen (O) at the base of the brackets were verified by means of the EDS, suggesting the occurrence of silica coating. MetalGlas group showed greater bond strength (9.38 ± 2.78 MPa) compared to the MetalU group (5.31 ± 1.2Mpa). Metal (8.82 ± 4.14 MPa) and MetalRoc (8.29 ± 3.95 MPa) groups showed similar bond strengths. The failure mode predominantly found in the sandblasted groups was the totally adhesive failure between resin composite and tooth. SignificanceThe sandblasting treatment using the glass beads was efficient in removing the remaining resin composite of recycled brackets and generated fewer surface defects and topographic changes in the bracket bases.