Journal of Orthodontic Science最新文献

Background: Enamel deproteinization using 5.25% sodium hypochlorite (NaOCl) or papain before enamel etching has been proposed to increase shear bond strength (SBS) of orthodontic brackets. Yet, evidence about its efficacy remains unclear.

Objective: This systematic review assesses the effects of enamel deproteinization on SBS and the adhesive remnant index (ARI) of orthodontic brackets bonded using different adhesives.

Material and methods: Four databases, PubMed, Cochrane Database of Systematic Reviews, Scopus, and Web of Science™ Core Collection, and gray literature were searched with no limitations up to May 2024.

Selection criteria: Randomized studies in vitro.

Data collection and analysis: Study selection, data extraction, and risk of bias assessment were done independently in duplicates. Random-effects meta-analysis of mean differences (MDs) with their 95% confidence intervals (CIs) were conducted, followed by subgroup analysis, sensitivity analysis, and the Grades of Recommendations, Assessment, Development and Evaluation analysis of the evidence quality.

Results: A total of 19 studies (including a total of 1399 extracted premolars) were included in this systematic review. These studies compared pretreatment with enamel deproteinization and bonding with bonding only without deproteinization. Low quality of evidence indicated that enamel deproteinization using 5.25% NaOCl did not have a statistical significance change on SBS (MD = -1.17, 95% CI: -2.35 to 0.02, P = 0.05) and ARI (MD = -0.27, 95% CI: -0.55 to 0.01, P = 0.06). On the other hand, enamel deproteinization using papain significantly increased the SBS (MD = -2.78, 95% CI: -4.49 to - 1.07, P = 0.001) and did not significantly increase the ARI (MD = -0.29, 95% CI: -0.58 to 0.01, P = 0.06). The main limitations of the existing evidence pertained to risk of bias, inconsistency, and imprecision of included studies.

Conclusion: Enamel deproteinization using 5.25% NaOCl showed no significant effects on SBS and ARI, while papain was associated with significantly higher SBS only with no significant effects on the ARI of orthodontic brackets bonded using resin composites or resin-modified glass ionomers.

Objectives: This range-finding study aimed to develop novel primer-less self-adhesive resins (SARs) for orthodontic bracket bonding that can provide clinically acceptable bond strengths and antibacterial effects and leave minimal remnant adhesive post-bracket debonding.

Materials and methods: Different concentrations of bioactive glass (BAG), strontium fluoride (SrF₂), and powdered grape seed extract (GSE) were added to a plain SAR to develop ten adhesive formulations for brackets bonding to extracted premolars, which were subjected to thermocycling (5000 cycles) prior to shear bond strength (SBS) and adhesive remnant index (ARI) assessments. Antibacterial activity and biofilm formation tests were conducted to evaluate the antibacterial properties of the developed SARs.

Results: The addition of 0.5% GSE to plain SAR + BAG 1% yielded the highest SBS value with minimal ARI, yet the differences were statistically insignificant (P > 0.05). The best antibacterial performance was demonstrated by the addition of 0.5% GSE, followed by 0.5% SrF₂ to the plain SAR + BAG group.

Conclusion: Incorporating 1% BAG, combinations of 0.5% SrF₂ + 3% BAG and 0.5% GSE + 1% BAG into a plain SAR yielded three newly developed formulations that provided clinically acceptable SBS with minimal adhesive remnants left on enamel post bracket debonding and improved antibacterial properties.

Background: Temporomandibular joint (TMJ) disorder refers to a condition involving dysfunction or pain in the jaw joint and the muscles that control jaw movement. It can affect one or both sides of the jaw and can cause various symptoms, including Jaw pain or tenderness; Difficulty or discomfort when chewing; Clicking, popping, or grating sounds in the jaw joint; Jaw locking or limited movement; Earache or pain around the ear; Headaches or migraines; Neck and shoulder pain; Swelling on the side of the face. TMJ disorder can have various causes, including injury to the jaw joint, teeth grinding or clenching (bruxism), arthritis, stress, misalignment of the jaw or teeth, and excessive gum chewing. Computer-aided drug design (CADD) comprises a range of theoretical and computational strategies employed in contemporary drug discovery. Molecular docking stands out as a key technique within CADD, aiding in the comprehension of drug-molecule interactions for rational drug design, mechanistic investigations, and the creation of stable complexes with heightened specificity and potential effectiveness. Through the docking process, valuable information regarding binding energy, free energy, and predictions of complex stability is obtained, offering significant insights into drug development endeavors.

Aim: The objective of this research was to employ docking methodology to identify potential ADAMTS-5 protein for TMJ. Four ADAMTS-5 protein inhibitors previously reported in the literature were selected, and their compound structures were obtained from the Zinc15 database. The ADAMTS-5 protein was designated as the target and optimized utilizing the RCSB Protein Data Bank. Following pharmacophore modeling, 20 novel compounds were identified, and SwissDock was utilized to dock these compounds with the target protein. A comparison was made between the binding energies of the newly discovered compounds and those of previously published molecules with the target.

Results: The results indicated that among the 20 ZINC1846088 and ZINC33606904 exhibited the highest binding energy and displayed superior properties compared to the other molecules.

Conclusion: The study concluded that ZINC1846088 and ZINC33606904 exhibited greater binding affinity than the reported inhibitors of ADAMTS-5 protein. Therefore, these two molecules can be used as a potential and promising lead for the treatment of TMJ and could be employed in targeted drug therapy.

Categories: Dentistry, TMJ.

Recent years have witnessed an increase in the popularity of macroesthetics (MES) in orthodontics, which focuses on gently and accurately increasing a patient's smile's esthetics. This systematic study's goal was to evaluate how well we currently understand how orthodontic MES affects a person's impression of their overall attractiveness. The terms "orthodontic aesthetics," "orthodontic macroesthetics," "aesthetic orthodontics," and "orthodontic smile design" were thoroughly searched across different online databases. There were a total of four papers that were relevant included in the review. The importance of MES in orthodontics and the need for orthodontists to use a complete and specialized approach to treatment were emphasized in all the articles that were being evaluated. An odds ratio (OR) of 0.69 [0.60, 0.79] and a risk ratio (RR) of 0.77 [0.70, 0.85] further highlight the statistical significance of the different parameters that were assessed in terms of the impact of MES on esthetic perception. All the articles included in the investigation provide a comprehensive account of the state of the science regarding MES in orthodontics. The results add to our understanding of MES perception in orthodontics, but because of the limitations of the included research, they should be evaluated with caution. This review protocol was registered on the International Prospective Register of Systematic Reviews (PROSPERO; registration number: CRD42023397221).

Introduction: Dental pulp may respond differently to adverse orthodontic forces. Major physiological effects of optimum orthodontic force application on dental pulp are vascular pulpal changes, pulpal calcification, and fibrosis. Functional appliances taking anchorage from the dentition tend to exert reciprocal higher orthodontic forces.

Objective: To evaluate the 3D volumetric changes of the dental coronal pulp of maxillary and mandibular permanent first molars 6 months after AdvanSync^TM fixed functional and Twin Block removable functional appliance therapy and followed at 18 months of treatment (T2).

Materials and methods: This retrospective study was performed on CBCT records obtained from a previous prospective study (Randomized Clinical Trial) comprising 32 patients [females: 17 (9.0-14.5 years), males: 15 (10.5-15.0 years)] who underwent functional mandibular advancement with Twin Block (group 1) and AdvanSync^TM (group 2). Pretreatment (T0), 6 months (T1), and 18 months (T2) follow-up CBCT were assessed for dental pulp volume by using ITK-SNAP software version 3.2.

Results: Intragroup volumetric pulpal changes showed a significant decrease in #16, #26, and #36 at time intervals T0-T1, T0-T2, and T1-T2 in groups 1 and 2. Intergroup comparison of pulpal volume for #16 and #26 was statistically significant at T1. A statistically significant decrease in pulpal volume for #46 was observed at time intervals T0-T1, T0-T2, and T1-T2 in both groups.

Conclusion: Functional appliance therapy with both Twin Block and AdvanSync^TM functional appliance tends to decrease the first molar pulpal volume.

Background: The self-ligating bracket system and corticision are two methods for acceleration of orthodontic tooth movement (OTM).

Objectives: The current study aimed to assess the effect of a self-ligating bracket system combined with corticision on the rate of OTM.

Patients and methods: The present study was conducted on 16 female patients divided into two groups: an experimental group of eight patients treated by self-ligating bracket systems used as fixed orthodontic appliances combined with a corticision as a minimally invasive surgical technique for accelerating OTM, and a control group of eight patients treated only by self-ligating bracket systems used as fixed orthodontic appliances. The primary outcome was the percentage of change in Little's Index of Irregularity (LII). The secondary outcome was the time taken to finish the leveling and alignment stage.

Results: In a comparison of the percentage of change in LII for the upper arch between the two groups, the experimental group recorded values that were significantly greater than those recorded in the control group at all time intervals T0-T7, except for T8-T10, which were similar. Both groups recorded (100 ± 0%), with no significant difference between groups (P = 1).

Conclusion: The combination of two methods for acceleration of OTM, a self-ligating bracket system combined with corticision, accelerates the rate of OTM more than in the case of using a self-ligating bracket system only.

Aim: Composite resins and bonding agents are indispensable in orthodontic practice, necessitating a thorough understanding of their cytotoxic effects, particularly when expired. This study aimed to evaluate the influence of expired composite and bonding materials on human gingival fibroblasts (hGFs).

Materials and methods: Both expired and nonexpired composite resins and bonding agents were tested on hGFs using direct exposure methods. Viability assays, morphological evaluations, and wound healing assays were conducted at 24 and 72 hours post exposure.

Results: Exposure to both expired and nonexpired materials led to significant reductions in hGF viability and alterations in morphology. Wound healing assays demonstrated impaired migratory abilities of hGFs following exposure to these materials.

Conclusion: The study highlights the importance of prudent material selection, handling, and monitoring in orthodontic practice to mitigate adverse effects on gingival tissues. Proper management of expired materials is crucial for cost-effectiveness, waste reduction, and patient safety. Further research into the long-term impacts of expired materials on gingival and periodontal health is imperative to ensure clinical treatment safety and efficacy. This investigation provides valuable insights into the biocompatibility of orthodontic bonding materials and emphasizes the necessity for continued vigilance in their usage to uphold patient welfare and treatment quality.

Objective: This study aimed to determine the difference in force decay between latex and non-latex elastic bands based on duration of use and salivary pH concentration.

Material and method: The calculation of the sample size in this study used Federer. Total sample size is 80 and divided into four groups. First group consists of 20 elastic bands made from latex immersed in artificial saliva pH 5.2, second group consists of 20 elastic bands made from latex immersed in artificial saliva pH 6.7, third group consists of 20 elastic bands made from non-latex immersed in artificial saliva pH 5.2, and fourth group consists of 20 non-latex elastic bands immersed in artificial saliva pH 6.7. All samples were incubated at 37°C, and force magnitude was measured with a digital force gauge.

Results: The most force decay occurred in the first 24 hours when immersed in artificial saliva and was constant for up to 72 hours. The elastic band immersed in salivary pH concentration showed greater force decay compared with pH 6.7 both latex and non-latex.

Conclusion: There was a significant difference in force decay of elastic bands made from latex and non-latex based on duration of elastic use. Force decay of elastic bands made from non-latex was greater than latex material. There was a difference in force decay elastic bands made from latex and non-latex based on the pH concentration of saliva. Force decay elastic band made from non-latex is greater than latex material and greater at pH 5.2 compared to 6.7.

Objective: The present study focused on evaluating and comparing the stresses and displacements generated by various designs of miniscrew-assisted maxillary expansion appliances. The primary focus of this study is on a modified design for treating unilateral maxillary constriction, analyzed using the finite element method (FEM).

Materials and methods: Using computed tomography (CT) scans and the modeling software Mimics, a three-dimensional (3D) mesh model of the skull and related maxillary structures was created. First, the necessary material characteristics were determined using FEM. Three models of miniscrew-assisted maxillary expansion appliances were then tested with ANSYS simulation software: (a) a bone-anchored rapid palatal expander (BARPE), (b) a conventional miniscrew-assisted rapid palatal expansion (C-MARPE), and (c) an asymmetric design of a MARPE focusing on unilateral expansion (U-MARPE). The asymmetric U-MARPE design features an attachment connecting the expander to the teeth on only one half of the maxilla. The stress, displacement, and distribution predictions for all three types of expanders were subsequently evaluated via FEM.

Results: Tooth displacement in the U-MARPE (on the expander-to-tooth attachment side) and C-MARPE groups was greater than that in the BARPE group. The stresses on the teeth were lowest in the BARPE and U-MARPE groups (on the expander-to-no-tooth attachment side). C-MARPE exhibited a symmetrical stress distribution around the miniscrew areas. Overall, U-MARPE generated the greatest amount of asymmetric von Mises stress and displacement on the dental landmarks.

Conclusion: This research indicates that, compared to other models, U-MARPE achieves more favorable unilateral expansion effects. The current U-MARPE design can be effectively used to correct unilateral transverse anomalies.