Fixed and removable orthodontic retainers, effects on periodontal health compared: A systematic review

Analysis of quality of life and periodontal health with an eight-unit maxillary fixed retainer through a prospective clinical trial

Retention is crucial in orthodontics, aiming to preserve treatment outcomes and enhance patient satisfaction with permanent fixed retainers. However, a removable retainer may be needed with fixed retainers to prevent unwanted changes. An eight-unit extended fixed retainer is proposed to eliminate the need for a removable retainer, addressing the undesired changes associated with six-unit fixed retainers. The impact of extended retainers on periodontium and quality of life remains unexplored. This study evaluates the periodontal response and patient-reported quality of life with an eight-unit maxillary fixed retainer. A single-arm prospective clinical trial with only twenty-eight test group patients (6 males, 22 females) who finished active orthodontic treatment were recruited. The mean age was (19.8 ± 4.5 years). This research was approved by the institutional review board of the Faculty of Dentistry, Alexandria University (IORG:0008839, No-0479-8/2022). The registration date of this study was (5/06/2023). An eight-unit maxillary fixed retainer was bonded to the palatal surface of the maxillary incisors, canines, and first or second premolars directly after debonding the brackets. The periodontal assessment and quality of life were carried out through clinical examination and valid questionnaires and the patients were followed up for 12 months. The periodontal response improved significantly at 1-year follow-up. The Probing depth, Gingival index, Plaque index, Bleeding index, and mobility index were significantly lower in these patients. Quality of life was assessed by the OHIP-14. The mean score decreased by -1.86 (SD = 4.19), and the acceptance of the orthodontic appliance scale score increased by 0.68 (SD = 0.86), which was significant with a p-value < 0.001. For 12 months of follow-up, an eight-unit maxillary retainer did not adversely affect the periodontal ligaments. meets patients' expectations and maintains a high quality of life.

Orthodontic retainers: are they all the same?

INTRODUCTION

It is known that the stability of the results obtained with orthodontic treatment depends, in addition to the functional and aesthetic aspects, also on the adequate planning of the retention devices, the patient's compliance with this new phase, and the physiological changes that the human body experiences over the years, throughout the craniofacial aging process.

OBJECTIVE

This article discusses the importance of the orthodontic retention phase and the influence of diagnosis, planning and execution of corrective treatment of malocclusions, in order to achieve the expected success.

METHODS

Throughout the text, different types of retainers and approaches during this phase will be presented, with the aim of ensuring the stability of the results obtained after correcting problems in the vertical, transverse and anteroposterior directions.

RESULTS

Orthodontic retainers are not all the same. The retention protocol must be performed in an individualized and planned manner, taking the initial dental positions as a reference.

CONCLUSIONS

The orthodontist must inform the patient and parents about important aspects of how to maintain the occlusion achieved with orthodontic treatment. The retainers installed after the end of corrective treatment are not everlasting, they can suffer damage with use and must be replaced. Therefore, the patient must be aware of the importance of using retainers as prescribed by the orthodontist, and of returning for scheduled review appointments.

A Novel 3-Dimensional Printed Nanoceramic Hybrid Resin Fixed Lingual Retainer: Characterization and Mechanical Tests

Introduction: An innovative retention protocol was developed to create a new 3D-printed fixed retainer employing SprintRay OnX nanoceramic hybrid resin. The feasibility and usability of the retainer were subsequently evaluated. Methods: Identification and characterization of SprintRay OnX was done using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy with energy dispersive X-ray (SEM-EDX), field emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD), and flexural strength. Load-deflection and pull-out tests were conducted on the 3D-printed straight wires, with three distinct cross-sectional geometries: round (1 mm), oval (1 mm × 1.5 mm) and semielliptical (1 mm × 1.5 mm). Twisted G&H and coaxial Respond stainless steel multistrand retainers were used for comparison. In the load-deflection test, a three-point bending test (3PBT) was employed. For the pull-out test, the retainer wire was inserted into the composite, which was placed in a centrally located hole of an acrylic block; the retainer wire was subjected to a tensile force along its long axis. Results: Characteristic bands close to those of PMMA were observed in the FTIR spectra. SEM-EDX and XRD revealed a crystalline material with homogeneously distributed Yb element signals (19.4%). On FE-SEM micrographs, small clumps were displayed on smooth surfaces. The flexural strength and the flexural modulus were, respectively, 142.48 MPa and 7.842 GPa. All groups of 3D-printed wires exhibited significantly higher load-deflection levels than the multistrand wires (MSWs). Concerning pull-out forces, they fell in between twisted G&H (96 N) and coaxial Respond (48.09 N) retainer wires. The 3D-printed wires fractured cohesively without detachment from the adhesive, suggesting that the chemical bond was adequate for satisfactory wire integration, yet the wire's strength was compromised. Concerning the cross-sectional geometry, the load-deflection and the pull-out forces of 3D-printed oval and semielliptical wires were significantly higher than that of 3D-printed round wires, which was attributed to the larger cross-sections of the wires. Conclusion: Oval and semielliptical 3D-printed wires offered favorable features as lingual retainers.

Can vacuum-formed retainers maintain arch dimensions and alignment compared to Hawley and fixed bonded retainers after treatment with fixed appliances? A systematic review and meta-analysis

BACKGROUND

Different types of retention appliances have been proposed over the years, but their effectiveness in maintaining arch dimensions and alignment after orthodontic treatment is still unclear.

AIM

To assess the efficacy of vacuum-formed retainers (VFRs) in preserving arch widths, arch length, and anterior alignment in maxillary and mandibular arches, compared to removable Hawley retainers (HRs) or fixed bonded retainers (FBRs). Search methods: unrestricted literature search of five major databases up to March 2024.

SELECTION CRITERIA

randomized/non-randomized clinical studies comparing VFRs to removable HRs or FBRs.

DATA COLLECTION AND ANALYSIS

after duplicate study selection, data extraction, and risk of bias assessment, random effects meta-analyses of standardized mean differences and their 95% confidence intervals were performed, followed by meta-regressions, sensitivity analyses, and assessment of the quality of evidence with GRADE.

RESULTS

Twenty-two prospective studies (4 non-randomized and 18 randomized controlled trials) involving 1797 patients (mean age 17.01 years, 38.3% males) were included. No significant differences were found in the intercanine width, intermolar width, and arch length between VFRs and HRs, in both arches (P > 0.05). However, VFRs were statistically more effective than HRs in terms of Little's irregularity scores (LII) in the maxilla (eight studies; SMD = -0.42; 95% CI: -1.03 to -0.09; P = 0.02; I2 = 73.4%) but not in the mandible (P = 0.12). No significant differences were reported for all considered outcomes between VFRs and FBRs in in both arches (P > 0.05), except for lower LII, where VFRs were significantly less efficient (eight studies; SMD = 1.49; 95% CI = 0.26-2.7; P = 0.02; I2 = 93%). Follow-up times, risk of bias, and wire type (of FBRs) did not show statistically significant effects on outcome variables. Sensitivity analyses showed robustness of the findings for including non-randomized and postretention studies. The certainty in these estimates was from moderate to low due to the risk of bias and inconsistency.

CONCLUSIONS

Low to moderate quality evidence indicates that VFRs are as effective as HRs in maintaining arch widths, length, and alignment. Low-quality evidence found similar efficacy between VFRs and FBRs, with FBRs being statistically more effective at maintaining lower arch alignment, but the difference was not clinically significant.

REGISTRATION

PROSPERO registration (CRD42024518433).

Correlation between HbA1c Levels and Periodontal Bacterial Load in Diabetic Patients with Fixed Retainers

BACKGROUND

Fixed orthodontic retainers can promote biofilm accumulation, increasing periodontal risks in patients with type 2 diabetes. This study examines the relationship between glycated hemoglobin (HbA1c) levels and bacterial load before and after oral hygiene intervention.

METHODS

Forty diabetic patients (HbA1c: 6.5%-9%) were divided into Group I (18-30 years, n=18) and Group II (>30 years, n=22). Periodontal samples were analyzed using micro-IDent® PCR tests. Pearson's correlation and linear regression assessed associations between HbA1c and bacterial load.

RESULTS

Pre-intervention bacterial loads were 66 (Group I) and 128 (Group II). Post-intervention, they decreased significantly to 34 and 93 (p≤0.05). HbA1c showed a strong pre-intervention correlation with bacterial load (r=0.78, p=0.002), decreasing post-intervention (r=0.42, p=0.08). Each 1% HbA1c increase correlated with a 20.3-unit rise pre-intervention (R²=0.61) and 8.2 units post-intervention (R²=0.18).

CONCLUSION

Fixed retainers facilitate bacterial colonization, worsening periodontal inflammation in diabetic patients. Glycemic control and regular oral hygiene interventions are essential for reducing bacterial load and preventing complications.

Effect of Vinyl Acetate, Glass Fibers Contents, and Buffer Space on EVA's Mechanical Property and Shock Absorption Ability

OBJECTIVES

 The aim of the study was to evaluate the mechanical properties and impact absorption capacity of prototype materials comprising ethylene vinyl acetate (EVA) of different hardness reinforced using different amounts of glass fibers (GFs), considering a buffer space.

MATERIALS AND METHODS

Six prototype materials were made by adding E-GFs (5 and 10 wt%) to EVA with vinyl acetate (VA) contents of 9.4 wt% ("hard" or HA) and 27.5 wt% ("soft" or SO). Durometer hardness and tensile strength tests were performed to evaluate the mechanical properties of the materials. Moreover, an impact test was conducted using a customized pendulum impact tester to assess the impact absorption capacity (with or without a buffer space) of the specimens.

RESULTS

The mechanical properties of the prototypes, namely, durometer hardness, Young's modulus, and tensile strength, were significantly higher in the HA group than in the SO group, regardless of the presence or added amount of GFs. The addition of GFs, particularly in a large amount (10 wt%), significantly increased these values. In terms of the impact absorption capacity, the original hardness of the EVA material, that is, its VA content, had a more substantial effect than the presence or absence of GFs and the added amount of GFs. Interestingly, the HA specimens with the buffer space exhibited significantly higher impact absorption capacities than the SO specimens. Meanwhile, the SO specimens without the buffer space exhibited significantly higher impact absorption capacities than the HA specimens. Moreover, regardless of the sample material and impact distance, the buffer space significantly improved impact absorption. In particular, with the buffer space, the impact absorption capacity increased with the added amount of GFs.

CONCLUSION

The basic mechanical properties, including durometer hardness, Young's modulus, and tensile strength, of the EVA prototype were significantly increased by reducing the amount of VA regardless of the presence or added amount of GFs. Adding GFs, particularly in large amounts, significantly increased the values of aforementioned mechanical properties. Impact absorption was significantly affected by the hardness of the original EVA material and enhanced by the addition of the buffer space. The HA specimen had a high shock absorption capacity with the buffer space, and the SO specimen had a high shock absorption capacity without the buffer space. With the buffer space, impact absorption improved with the amount of added GFs.

Microbiological Analysis of Plaque and Its Composition in Three Patient Groups under Different Orthodontic Treatments

BACKGROUND

This article analyzes differences in microbiological parameters and periodontal health conditions among three patient groups: those undergoing conventional orthodontic treatment with fixed appliances, patients undergoing orthodontic treatment with clear aligners, and a control group receiving no treatment.

MATERIALS AND METHODS

In this study, 60 patients were enrolled. The microbiological analysis employed a qualitative and semi-quantitative methodology of bacterial morphotype analysis.

RESULTS

The analyses revealed a significant difference in favor of clear oral and periodontal health aligners. This could be attributed to better bacterial biofilm removal and reduced mechanical stress on the periodontal ligament, factors facilitated by the ease of clear aligner removal. Significant differences (p-value < 0.05) were observed for the Full-Mouth Plaque Score, Full-Mouth Bleeding Score, Plaque Index, and periodontal health assessment measurements.

CONCLUSIONS

Although overall hygiene appears to be improved in patients in the aligners group compared to those treated with conventional orthodontic appliances, there are no statistically significant results regarding plaque composition. Microbiological aspects will be further addressed using more specific techniques in the follow-up of this research.

Prefabricated Zirconia Crowns and Preformed Metal Crowns in the Treatment of Severely Childhood Caries and Anterior Crossbite in a Child with Autistic Spectrum Disorder

Crowns have been recommended to treat decayed teeth and rebuild teeth function. The dental management of children with autism is a tremendous challenge for pediatric dentists due to the impaired behaviors and communication disorders. In this context, a 5-year-old boy with autism was treated to solve carious lesions under the assistance of general anesthesia. The posterior occlusal function was restored, and the crossbite existing in the primary anterior teeth was approached merely by NuSmile® zirconia crowns (ZCs) rather than orthodontic intervention. We conducted an 18-month period. Throughout the long-term follow-up, the boy's masticatory efficiency was remarkably improved and the anterior teeth had transferred into the correct position with adequate overbite to maintain the new relationship, thus ameliorating the appearance of tissue on the labial surface and enhancing his quality of life and oral health.