Search Results (9)

Objectives: The aim of this study was to compare the hardness, chemical composition, and microstructure of various self-ligating ceramic orthodontic brackets and enamel. Methods: Sixty ceramic brackets (0.022″ × 0.028″) from six different orthodontic firms (Damon^® Clear 2, Genius^® Crystal, Empower^® 2 Clear, Clarity^® Ultra, Alpine SL^® Clear, and Experience Ceramic^®) were tested using a microhardness tester and a scanning electron microscope (SEM) equipped with energy-dispersive spectroscopy (EDS). Results: The hardness of the ceramic brackets ranged from 1969.8 to 2567.3 VH. The statistical analysis using the Kruskal–Wallis and Mann–Whitney tests revealed significant differences in microhardness between most of the ceramic brackets. Additionally, this study found that passive self-ligating brackets exhibited a significantly higher hardness than that of active self-ligating brackets (p = 0.01). The SEM analysis showed that the variations in the oxygen and alumina composition between the six bracket types were also statistically significant (p = 0.01). Conclusions: Among all of the ceramic brackets tested, Alpine^® brackets displayed the lowest hardness values, making them a potential choice for minimizing enamel damage. Notably, the hardness of self-ligating ceramic brackets was found to be at least six times greater than that of enamel, raising concerns about their potential to cause trauma to the enamel of antagonistic teeth. Consequently, the researchers recommend avoiding bonding ceramic brackets to the mandibular teeth or elevating occlusion with turbo-bites to prevent traumatic contact during treatment. Full article

Aim: Cytokines are crucial low-molecular-weight proteins involved in immune responses. This systematic review highlights the need for in-depth studies on cytokines’ biological mechanisms, providing insights into disease onset and potential therapeutic strategies. Materials and methods: A comprehensive literature search identified 18 relevant articles, emphasizing the multifaceted role of cytokines in orthodontic treatment (OT). The quality assessment using the ROBINS-I tool ensures a rigorous evaluation of the included studies, contributing to the overall reliability of the findings. Results and Conclusions: This systematic review explores the intricate relationship between cytokines and OT. Cytokines exhibit different properties, influencing cellular activities through autocrine, paracrine, and endocrine activities. OT, aimed at achieving stable occlusion, induces tension and compression in the periodontal ligament (PDL), triggering cytokine release. Proinflammatory cytokines play a role in inflammation, influencing bone and soft tissue metabolism. Studies show elevated cytokine levels in gingival crevicular fluid (GCF) after orthodontic force application. The choice of orthodontic devices, such as self-ligating brackets, influences cytokine concentrations, indicating the importance of attachment design. Further research promises to enhance orthodontic practices, and optimize patient care. Full article

Passive self-ligating bracket systems (PSLBs), such as the Damon^® system (Ormco, US) and SmartClip (3M Unitek^®, US) claim advantages over other types of brackets regarding efficiency and effectiveness. However, some studies have questioned their qualities, particularly during the alignment stage, in arch development, and regarding stability of results. This article aims to conduct a scoping review from the past decade’s literature (2013–2023) regarding these assertions about PSLBs. A comprehensive search was performed on several databases. With at least one comparison between PSLBs and the other two bracket types, the inclusion criteria were restricted to English-written randomized controlled trials and split-mouth design studies involving patients receiving orthodontic treatment using PSLB, active self-ligating bracket systems (ASLBs), or conventional/traditional bracket systems (CBs). After screening and manual analysis of the selected studies, only 39 were chosen for the review. Most of the efficiency and effectiveness results from research conducted in the past ten years did not indicate any appreciable differences between the three different types of brackets; therefore, the evidence on whether PSLB is better than CBs and ASLBs is equivocal. Further research is necessary to understand the distinctions between passive self-ligating and other bracket systems and establish the optimal utilization of each system in clinical settings. Full article

Background and Objectives: Orthodontic tooth movement (OTM) requires bone remodeling resulting from complex processes of aseptic inflammation. Recent studies have confirmed close interaction between the immune and skeletal systems. In addition, various orthodontic appliances including fixed systems affect the sublingual microbial composition, and the likelihood of developing inflammatory reactions of the gums is high, especially early in the treatment period. It is known that these systems have both positive and negative effects on the humoral and cellular immune responses. The main aim of the study was to evaluate the influence of self-ligating and conventional brackets on the salivary concentrations of cytokines (IL-6, osteoprotegerin (OPG), TNF-alpha, and IFN-gamma) and cortisol as a marker of stress. Materials and Methods: Forty patients were analyzed at baseline (T0) and 2 months (T2) after fixing self-ligating (Ormco Damond Q) and conventional brackets (Ormco Mini Diamond). Salivary cytokine and cortisol concentrations were evaluated by commercial ELISA kits. Results: Outcomes of our study showed that after two months of treatment with either of these brackets, IFN-gamma and IL-6 levels did not change. However, TNF-alpha decreased with self-ligating brackets (13.36 to 8.32, p = 0.002). The self-ligating bracket system also affects OPG concentration and cortisol levels 2 months after orthodontic activation. The level of OPG in the group of self-ligating brackets decreased significantly (8.55 to 2.72, p = 0.003). Cortisol concentration was significantly higher in the self-ligation group (25.72 to 48.45, p = 0.001) due to the effect of sustained strength movements. Conclusions: Thus, the use of self-ligating and conventional brackets has a different effect on the concentration of cortisol and cytokines (OPG and TNF-alpha) in saliva 2 months after their fixation. Further longitudinal studies are necessary to explore why OPG levels are decreased in case of self-ligating cases and how OPG levels are related to clinical improvement. Full article

Adhesion remains a key element in dentistry, whether approached in prosthetics, odontology, or orthodontics. It is a continuously researched aspect, as improved materials and adhesive methods keep emerging in the market. No orthodontic treatment can be effective without the proper adhesion strength of the bonded elements on the teeth. The objective of this research, in the broad context of self-ligating versus conventional brackets, was to compare active and passive self-ligating systems with a conventional one by conducting an in vitro study on human-extracted premolars. Shear bond strength tests were executed by means of an advanced materials-testing machine that generated maximum load and tensile strength values. The data obtained underwent statistical analysis with a statistical threshold of p < 0.05. The results regarding the statistical significance were acquired when comparing the passive self-ligating system with the active self-ligating and conventional systems (load-at-maximum-load mean 204.9, SD 91.09, and p < 0.05). In this study, the passive self-ligating bracket system appears to present increased shear bond strength. Full article

The aim of this work was to determine advanced the oxidative protein products (AOPPs), total antioxidant capacity (TAC), and myeloperoxidase activity (MPO) in the saliva of patients undergoing orthodontic treatment with clear removable aligners in comparison with another group in treatment with fixed passive self-ligating brackets applying light forces, before treatment, after 30 days, and after 90 days of treatment. This non-randomized clinical trial recruited patients consecutively, all of which were over 18 years of age and due to undergo orthodontic treatment. They were divided into two groups according to treatment type: Group A, 48 patients treated with clear aligners (Invisalign^®); and Group B, 19 patients treated with Damon System^® 0.22″ self-ligating brackets applying light forces. Saliva samples were collected by a single clinician following the same protocol and underwent three analyses—AOPPs, TAC, and MPO levels–at baseline before placing the apparatus, after 30 days, and after 90 days treatment. Orthodontic treatment, whether with clear aligners or fixed self-ligating brackets and light forces, increased AOPPs after the first 30 days of treatment. During the initial phases of orthodontic treatment, neither clear aligners nor fixed self-ligating brackets applying light forces showed changes in TAC and MPO. Orthodontic treatment with both clear aligners and fixed apparatus self-ligating brackets applying light forces increases oxidative stress (AOPPs) after the first 30 days of treatment. There are no differences in AOPP levels between treatment with clear aligners and self-ligating brackets during the first 90 days of treatment. The antioxidative capacity of saliva during the initial phases of orthodontic treatment, whether with self-ligating brackets or clear aligners, does not undergo significant changes. With either orthodontic technique, the patients’ salivary antioxidant capacity is similar. Full article

Friction is an intensely studied feature in orthodontics, as the sliding mechanics approach remains one of the most utilized techniques in current practice, and the question of whether self-ligating brackets produce less friction than conventional brackets still stands. The objective of this study was to compare a self-ligating system with different closing mechanisms and a conventional system with different ligating mechanisms regarding their frictional properties. Laboratory measurements were performed using an advanced materials testing machine generating tensile strength and load at maximum Load values, which were statistically analyzed and compared. These two parameters have been associated with the frictional resistance generated at the archwire–bracket slot interface. Statistically significant results were obtained when comparing the active self-ligating brackets with the passive self-ligating (tensile strength mean 1.953, SD 0.4231; load at maximum moad mean 6.000, SD 1.3000) and conventional brackets (tensile strength mean 1.953, SD 0.4231; load at maximum load mean 6.000, SD 1.3000), as well as when comparing the passive self-ligating brackets with the conventional brackets (tensile strength mean 1.708, SD 0.8628; load at maximum load mean 5.254, SD 2.645). The active self-ligating brackets tended to produce more friction when compared to the passive self-ligating brackets but were similar to conventional brackets with stainless steel ligatures. Full article

Aim: This study evaluates the role of low-level laser emission/photobiomodulation (LE/P) in quantitative measurements of root resorption (QRR). The application of LE/P performed after each orthodontic activation with four types of treatment intervention (TI) on the root resorption (RR) after fixed orthodontic treatment (FOT) of the upper arch with ectopic eye tooth/teeth [EET] was investigated. Materials and Methods: Thirty-two orthodontic patients scheduled for FOT were selected and assigned to the four groups. These were LE/P + Self ligating bracket (SLB), LE/P + Conventional bracket (CB), non-photobiomodulation (non-LE/P) + SLB and non-LE/P + CB. Standard management stages of FOT were followed in the maxilla. Each patient received a single application of LE/P labially/buccally and palatally, a total of five different points were used during each activation or appointment. The main outcome measure was QRR in maxillary anteriors before and after FOT, assessed via cone-beam computed tomography (CBCT) using 3D OnDemand software. Results: Insignificant QRR was found between before and after FOT in SLB, CLB, and LE/P, non-LE/P groups (p > 0.05). QRR in the SLB vs. CB and LE/P vs. non-LE/P group was significantly different in 11, 13, and 23 (p < 0.05). QRR in the LE/P + SLB group (p < 0.05) was significantly different in 11, 13, and 23 than that in the other groups. The most severe QRR was found on 13 (0.88 ± 0.28 mm and 0.87 ± 0.27 mm) and 23 (1.19 ± 0.14 mm and 1.16±0.13 mm) in the CB and non-LE/P group (p < 0.001). LE/P + SLB showed a highly significant superior outcome (p < 0.001) in relation to non-LE/P + CB, the QRR of 23 were 0.813 ± 0.114 mm and 1.156 ± 0.166 mm, respectively. Conclusion: Significantly higher amounts of QRR were found in EET patients after FOT treated with the CB, non-LE/P, and non-LE/P + CB system and warrant further investigation to explore potential specific causes. Full article

Many advantages have been described surrounding self-ligating (SL) brackets compared to metallic conventional ligating (CL) brackets, such as: Less total treatment time, alignment efficiency, patient comfort, plaque retention, and low friction. The objective of this in vitro simulation was to know the variables that affect arch displacement in CL and SL brackets—active (ASL) and passive (PSL)—and analyze if static friction values are affected by bracket design, arch wire section, kind of ligature, and use of a friction reducer agent (FRA) in a wet state. Larger values of static friction were found in CL with metallic ligature (ML) (8.01 ± 1.08 N/mm) and elastic ligature (EL) (6.96 ± 0.48 N/mm). Lower values were found in PSL brackets combined with FRA (0.58 ± 0.21 N/mm). The study was carried out using different stereographical models of a maxillary upper right quadrant with canine, first and second premolar, and first molar bonded brackets. A section of 25 mm of 0.019 × 0.025” stainless steel arch with a rectangular section (SS) and hybrid section (HY) was inserted into the different bracket models. Static friction values were collected using a universal test machine in wet conditions and testing the effect of a friction reducer agent (FRA). To assure the reliability of the study, different wire combinations were repeated after two weeks by the same operator and a linear analysis of regression was done. Each bracket model analysis—with the different wires, use of the FRA, and comparison among brackets in similar conditions—was done using an ANOVA test with a confidence interval of 95% and comparative Post-Hoc tests (LSD). In this in vitro simulation we found higher static friction values in CL compared to ASL and PSL. In PSL, lower values were achieved. CL brackets using ML showed the highest static friction values with a great variability. In this setting, the use of HY wires did not reduce static friction values in ASL and PSL, while in CL brackets with EL friction the values were reduced significantly. An FRA combined with ASL reduced significantly static friction values but not with PSL. In the case of CL, the FRA effect was higher with SS and better than with HY wires. ML values were similar to ASL static friction. The direct extrapolation of the results might be inaccurate, since all these findings should be tested clinically to be validated. Full article