Innovative evaluation of local injective gel of curcumin on the orthodontic tooth movement in rats

Post-Orthodontic Relapse Prevention through Administration of a Novel Synthetic Carbonated Hydroxyapatite-Chitosan Hydrogel Derived from Blood Cockle Shell (Anadara granosa L.)

Relapse during passive orthodontic treatment is a major issue, with 70-90% frequency. This study examines whether blood cockle shells may be used to extract carbonated hydroxyapatite (CHA)-chitosan (CS). This study also aims to analyze the effect of CHA-CS on orthodontic relapse in rats. This study utilized 18 male Wistar rats which were randomly divided into two groups: CHA-CS and the control group (CG). The rats were subjected to a 35 cN orthodontic force for a duration of 7 days, after which the rats were conditioned to be passive. During this phase, the CHA-CS group received daily administration of CHA-CS hydrogel derived from the blood cockle shell. Subsequently, the appliances were detached to facilitate relapse. The distance between the mesial tips was measured using a digital caliper at three consecutive time points: 1, 5, and 7 days after debonding. The number of osteoblasts, osteoclasts, and fibroblasts was examined using hematoxylin-eosin staining. The data were subjected to statistical analysis using a t-test. The relapse distance of the CHA-CS group was lower than that of the control groups on day 7. Histological examinations using hematoxylin-eosin (HE) staining showed a significant increase in osteoblasts, a decrease in osteoclasts, and an increase in fibroblasts during orthodontic relapse movement (p < 0.05). This study found that blood cockle shell-derived CHA-CS may reduce orthodontic relapse by increasing osteoblasts and fibroblasts and by reducing the osteoclast number in rats.

Under pressure-mechanisms and risk factors for orthodontically induced inflammatory root resorption: a systematic review

BACKGROUND

The application of orthodontic forces causes root resorption of variable severity with potentially severe clinical ramifications.

OBJECTIVE

To systematically review reports on the pathophysiological mechanisms of orthodontically induced inflammatory root resorption (OIIRR) and the associated risk factors based on in vitro, experimental, and in vivo studies.

SEARCH METHODS

We undertook an electronic search of four databases and a separate hand-search.

SELECTION CRITERIA

Studies reporting on the effect of orthodontic forces with/without the addition of potential risk factors on OIIRR, including (1) gene expression in in-vitro studies, the incidence root resorption in (2) animal studies, and (3) human studies.

DATA COLLECTION AND ANALYSIS

Potential hits underwent a two-step selection, data extraction, quality assessment, and systematic appraisal performed by duplicate examiners.

RESULTS

One hundred and eighteen articles met the eligibility criteria. Studies varied considerably in methodology, reporting of results, and variable risk of bias judgements.In summary, the variable evidence identified supports the notion that the application of orthodontic forces leads to (1) characteristic alterations of molecular expression profiles in vitro, (2) an increased rate of OIIRR in animal models, as well as (3) in human studies. Importantly, the additional presence of risk factors such as malocclusion, previous trauma, and medications like corticosteroids increased the severity of OIIRR, whilst other factors decreased its severity, including oral contraceptives, baicalin, and high caffeine.

CONCLUSIONS

Based on the systematically reviewed evidence, OIIRR seems to be an inevitable consequence of the application of orthodontic forces-with different risk factors modifying its severity. Our review has identified several molecular mechanisms that can help explain this link between orthodontic forces and OIIRR. Nevertheless, it must be noted that the available eligible literature was in part significantly confounded by bias and was characterized by substantial methodological heterogeneity, suggesting that the results of this systematic review should be interpreted with caution.

REGISTRATION

PROSPERO (CRD42021243431).

Enhancing Therapeutic Efficacy of Curcumin: Advances in Delivery Systems and Clinical Applications

Curcumin, a potent active compound found in turmeric and Curcuma xanthorrhiza oil, possesses a wide range of therapeutic properties, including antibacterial, anti-inflammatory, antioxidant, and wound healing activities. However, its clinical effectiveness is hindered by its low bioavailability and rapid elimination from the body. To overcome these limitations, researchers have explored innovative delivery systems for curcumin. Some promising approaches include solid lipid nanoparticles, nanomicelle gels, and transdermal formulations for topical drug delivery. In the field of dentistry, curcumin gels have shown effectiveness against oral disorders and periodontal diseases. Moreover, Pickering emulsions and floating in situ gelling systems have been developed to target gastrointestinal health. Furthermore, curcumin-based systems have demonstrated potential in wound healing and ocular medicine. In addition to its therapeutic applications, curcumin also finds use as a food dye, contraception aid, corrosion-resistant coating, and environmentally friendly stain. This paper primarily focuses on the development of gel compositions of curcumin to address the challenges associated with its clinical use.

A Comprehensive Review on Drug Therapies and Nanomaterials used in Orthodontic Treatment

Orthodontic treatment typically requires an extended duration of 1-2 years to complete the treatment. Accelerating the rate of tooth movement during orthodontic treatment is essential for shortening the overall treatment duration. After the completion of orthodontic treatment, a prominent concern arises in the form of orthodontic relapse, where the teeth tend to revert to their original positions. This issue affects approximately 60% of the global population, underscoring the importance of implementing effective measures to address orthodontic relapse. An approach in this regard involves the targeted administration of herbal and synthetic drugs applied directly to the specific area of interest to facilitate tooth movement and prevent orthodontic relapse. Apart from this, researchers are investigating the feasibility of utilizing different types of nanoparticles to improve the process of orthodontic tooth movement. In recent years, there has been a noticeable increase in the number of studies examining the effects of various drugs on orthodontics. However, the currently available literature does not provide significant evidence relating to orthodontic tooth movement. In this review, the authors provide valuable information about the drugs and nanomaterials that are capable of further enhancing the rate of orthodontic tooth movement and reducing the risk of orthodontic relapse. However, a notable hurdle remains, i.e., there is no marketed formulation available that can enhance orthodontic tooth movement and reduce treatment time. Therefore, researchers should try herbal-synthetic approaches to achieve a synergistic effect that can enhance orthodontic tooth movement. In this nutshell, there is an urgent need to develop a non-invasive, patient-compliant, and cost-effective formulation that will provide quality treatment and ultimately reduce the treatment time. Another critical issue is orthodontic relapse, which can be addressed by employing drugs that slow down osteoclastogenesis, thereby preventing tooth movement after treatment. Nevertheless, extensive research is still required to overcome this challenge in the future.

Potency of hyaluronic acid from eggshell-membrane for open gingival embrasure reconstruction following orthodontic tooth movement (a histomorphological study)

Background

The aim of this research was to assess the effectiveness of eggshell-membrane (ESM)-containing hyaluronic acid (HA) in the treatment of open gingival embrasure (OGE) following orthodontic tooth movement (OTM).

Materials and Methods

This study is an in vivo quasi experimental research. A total of 24 Cavia cobaya were equally divided into two groups, treatment (10% HA injection) and control (phosphate-buffered saline [PBS]). A separator was inserted between mandibular incisors to induce an OGE. A volume of 20 μl of either PBS (n = 12) or ESM extract (n = 12) was locally injected within the interdental papilla. Decapitation of animals was made on day 1, 4, and 7 postinjection. The staining was done using hemotoxylin and eosin to observe angiogenesis and Mallory to observe the collagen density. Fourier-transform infrared spectroscopy (FTIR) and thin-layer chromatography (TLC) analysis were performed to detect the amount of HA available in ESM. The results were then compared with independent t-tests and the Mann-Whitney test. The level of statistical significance was set at 0.05.

Results

The FTIR and TLC analysis showed that HA was successfully identified in the ESM samples. Local injection of 10% HA induced an increase of angiogenesis compared to the control group on day 1 and 4 postinjection (P < 0.05). Significant differences (P < 0.05) were also noted in the collagen density and the growth of interdental papilla on day 4 and 7 postinjection.

Conclusion

ESM has the potential effect of regenerating the interdental papilla construction after OTM by increasing the collagen fiber density and inducing angiogenesis.

Use of Hydrogels to Regulate Orthodontic Tooth Movement in Animal Models: A Systematic Review

The objective of this article is to conduct a systematic review of the literature to contrast the existing evidence regarding the use of hydrogels during and after experimental orthodontic treatment in animals. An extensive search was performed through the electronic databases, Medline, Web of Science and Scopus, from December 2020 to April 2021 for in vivo animal studies. A total of 282 studies were reviewed. Eight studies were included for final revision; four studies were conducted in rats, two in rabbits, one study in mice and one study in guinea pigs. The quality assessment of the eight included studies was performed according to the ARRIVE guidelines and the risk of bias was assessed using the Center for Systematic Review of Laboratory Animal Experimentation tool; in four of the eight articles evaluated, a high risk-of-bias rating was obtained in 40% of the criteria evaluated. In the studies reviewed, the hydrogel acted as a carrier, and inhibition (post-treatment retention) or acceleration of orthodontic tooth movement was assessed according to the active substance used in each of the articles. The uses of hydrogels for transporting active substances to regulate the rate of orthodontic tooth movement remains debatable. Future studies are suggested to evaluate the feasibility of hydrogel as a transport method in humans.

A sustained-release Trametinib bio-multifunction hydrogel inhibits orthodontically induced inflammatory root resorption

Orthodontic tooth movement (OTM) is a bone reconstruction process. In most cases, OTM could induce root resorption as a common side effect, called orthodontically induced inflammatory root resorption (OIIRR). OIIRR affects tooth health and interferes with the stability of orthodontic treatment. Osteoclasts, which perform bone resorption in OTM, attack cementum, causing OIIRR. Many signaling pathways are involved in the maturation and differentiation of osteoclasts, among which the ERK1/2 is one of the important pathways. In this experiment, we added Trametinib (Tra), a specific inhibitor of ERK1/2, to catechol-modified chitosan (CHI-C) and oxidized dextran (ODex) to form a CCOD-Trametinib composite hydrogel (CCOD-Tra) to prevent OIIRR. CCOD-Tra exhibited good biocompatibility, injectability, strong adhesion, good hemostatic function and sustained release of Tra. We performed local injection of CCOD-Tra into the periodontal tissues of rats. CCOD-Tra firmly adhered to the periodontal tissues and then released Tra to establish a good biological environment and maintain a drug concentration at a high level around the roots for a long time. H&E, TRAP, immunochemistry staining and micro-CT indicated that CCOD-Tra had a good effect in terms of preventing OIIRR. Cell experiments showed that CCOD-Tra reduced the expression of TRAP, MMP-9 and C-FOS in osteoclast cells through the ERK1/2 signaling pathway to inhibit the differentiation and maturation of osteoclasts. Based on the above results, we concluded that CCOD-Tra had the ability to prevent OIIRR, the high adhesion and injectability of CCOD may provide better therapeutic ideas for clinical prevention of OIIRR.

Effect of Methotrexate Injection on Orthodontic Tooth Movement: An Experimental Study on Rats

INTRODUCTION

Knowledge about the effects of medications, vitamins, and various supplements on orthodontic tooth movement (OTM) is imperative for orthodontists. This study aimed to assess the effect of methotrexate (MTX) injection on OTM in rats.

MATERIALS AND METHODS

Twenty-eight male Wistar rats were randomized into four groups (n = 7). The first molar and central incisor were connected using a nickel-titanium (NiTi) coil spring with a 50 g load in each rat. The two experimental groups received 0.75 mg/kg and 1.5 mg/kg MTX, respectively, intraperitoneally for 21 days. The negative control group did not receive any injection and did not undergo orthodontic treatment. The positive control group underwent orthodontic treatment and received 0.9% saline (NaCl) injections for 21 days. All rats were sacrificed with chloroform inhalation after 21 days; their maxilla was resected, and the mean number of Howship's lacunae, blood vessels, osteoclasts, and resorption lacunae was counted. The reduction in bone volume (bone volume to total volume ratio (BV/TV)) at the site of the maxillary molar was quantified by microcomputed tomography (micro-CT).

RESULTS

OTM, the number of osteoclasts, and the number of blood vessels significantly increased in rats treated with MTX (P < 0.05). However, the increase in the number of Howship's lacunae and resorption lacunae was not significant (P > 0.05). Lower BV/TV in the MTX groups was in agreement with the increased number of osteoclasts.

CONCLUSION

Injection of MTX can significantly increase OTM and decrease root resorption in rats.

Curcumin inhibits the migration of osteoclast precursors and osteoclastogenesis by repressing CCL3 production

BACKGROUND

Curcumin can inhibit the osteoclastogenesis and the migration of several cells including macrophages. Osteoclast precursors (OCPs) are known to exist as bone marrow-derived macrophages (BMMs). This study aims to explore whether curcumin can prevent the fusion and differentiation of OCPs to mature osteoclasts by inhibiting OCP migration.

METHODS

In this study, we investigated the role of curcumin in regulating the production of several chemokines (CCL2, CCL3 and CX3CL1) and the migration of OCPs by ELISA, Western blotting and Transwell assays. Furthermore, we explored the role of curcumin in the chemokines-related osteoclastogenesis using pharmacological intervention and virus infection, and used ovariectomized (OVX) mice (osteoporosis model) to explore the effect of curcumin on the production of specific chemokine in vivo.

RESULTS

The results showed that curcumin significantly reduced the production of CCL3 in OCPs. Moreover, curcumin-inhibited the migration of OCPs was not affected by CCR1 (Receptor of CCL3) overexpression. Remarkably, curcumin-reduced osteoclastogenesis was significantly reversed by CCL3 addition, while CCR1 overexpression did not increase the osteoclastogenesis in the presence of curcumin. Furthermore, in vivo assays also showed that curcumin significantly reduced the production of CCL3 in OCPs in the trabecular bone of OVX mice.

CONCLUSIONS

In conclusion, curcumin prevents the migration of OCPs by reducing CCL3 production, ultimately inhibiting the formation of mature osteoclasts. Therefore, our study provides the clues for improving the clinical strategies of osteoporosis, dental implantation or orthodontic treatment.

Wheat seeds can delay orthodontic tooth movement by blocking osteoclastogenesis in rats

Background

The hormone estrogen can prevent osteoclast differentiation and suppress osteoclastic activity, which can prevent tooth relapse movement. Wheat seeds are a natural material containing phytoestrogens with similar characteristics to estrogen.

Objective

This study intends to determine the influence of wheat seeds in reducing osteoclastogenesis following orthodontic tooth movement (OTM).

Materials and methods

Forty male Sprague Dawley rats were used in this experimental study. The rats were divided into control and treatment groups (n=20). In both groups, the rat maxillary incisors were moved distally using a 0.012 U stainless steel orthodontic appliance with a 2 mm diameter coil and 5 mm wire length. The treatment group received wheat seeds at a dose of 0.6 gram/day. The animals were sacrificed at days 0, 1, 7, and 14 after using the orthodontic appliance (4 subgroups according to observations of days; n=5). RANKL and OPG expressions were determined from the gingival crevicular fluid (GCF) samples using ELISA analysis. Statistical analysis of the data collected was calculated with the independent sample t-test (P<0.05).

Results

All the experimental procedures were well-tolerated and did not change the animals’ weight. On days 7 and 14, the OTM rate of the treatment group was significantly lower than the control group (P<0.05). ELISA test results showed that the OPG level was significantly higher on days 1, 7, and 14, while the RANKL level was considerably lower on day 14 in the wheat seeds group compared with the control group (P<0.05).

Conclusion

Wheat seeds can promote osteoclastogenesis inhibition and delay OTM.