In vitro Analysis of Tooth Movement Using Clear Aligners versus Traditional Brackets

ABSTRACT

Introduction:

Correcting malocclusions with controlled dental displacement is one of the objectives of orthodontic treatment.

Materials and Methods:

Over time, the two main treatment choices that have surfaced are the transparent aligners and the traditional braces.

Results:

This work explores the efficacy of clear aligners and conventional braces in terms of tooth movement, biomechanical features, and patient-centered outcomes using an in vitro approach.

Conclusion:

By means of movement correctness, velocity, and prospective consequences, the study offers a whole knowledge of the benefits and drawbacks connected with every therapy modality.

INTRODUCTION

Orthodontic treatment has traditionally relied on fixed devices—often metal or ceramic brackets.[1] These devices rectify misalignments by constantly stressing the teeth, therefore helping them. By giving patients an esthetically beautiful and removable alternative, Invisalign and other introduction of clear aligners have fundamentally changed the practice of orthodontics.[2] Clear aligners have become very popular as an orthodontic treatment as they are more esthetically pleasing and easier than conventional braces for straightening teeth. Made of translucent medical-grade plastic, these custom-fitted trays progressively bring teeth into ideal alignment without the need of wires or metal braces. Clear aligners may be removed; thus, eating is more practical and keeping dental hygiene is easier.[3] Those seeking a less obvious treatment option—especially adults and teenagers—find their subdued look appealing. Healthcare providers must have a strong awareness of the biomechanical variations between these two therapeutic approaches if they are to advise the most suitable treatment strategy for a certain patient. The aim of this study was to evaluate the efficacy and precision of tooth movement attained by the use of transparent aligners to that achieved by the use of traditional braces in an in vitro environment intended to replicate clinical situations. To help clinical decision-making, we want to offer a comparison grounded on data. Analyzing tooth movement, applied forces, and root resorption probability during the process helped to achieve this.

MATERIALS AND METHODS

This study employed 20 standardized artificial tooth models specifically engineered to simulate prevalent malocclusions, such as crowding, spacing, and rotations. The models were classified into two distinct categories: Group A: Received treatment with clear aligners; Group B: Received standard metal brackets for administration.

For Group A, customized aligners were fabricated via 3D printing, employing initial digital photographs of the models. The aligners were meticulously designed to facilitate the gradual movement of teeth in increments of 0.25 mm. Each aligner was employed for a period of 2 weeks, in accordance with established clinical protocols.

Group B received conventional metal brackets featuring 0.022-inch openings, accompanied by archwires made of nickel–titanium and stainless steel. Orthodontic elastics were utilized to simulate force applications comparable to those found in an authentic orthodontic setup. Tooth displacement was evaluated biweekly in both cohorts using digital calipers and sensors. The forces applied by the aligners and brackets were measured using pressure sensors at baseline, midtreatment, and the end of the simulated treatment time. The degree of tooth displacement achieved after 12 weeks of simulated therapy was recorded. Temporal fluctuations in the applied force were examined. A post-treatment analysis of tooth roots was performed to detect signs of resorption, a common negative consequence of orthodontic movement.

RESULTS

Group A, utilizing clear aligners, exhibited a cumulative tooth movement of 3.17 ± 3.05 mm over a 12-week duration, demonstrating superior control over both vertical and rotational displacement. Nevertheless, the lateral movements (crowding adjustments) were executed at a slower pace compared to those attained with conventional brackets. Group B (conventional brackets) displayed a total tooth displacement of 3.96 ± 4 mm, indicating an expedited lateral movement while exhibiting slightly reduced control over rotational adjustments [Table 1].

Table 1.

Group descriptives

	Group	n	Mean	Median	SD	P
Force distribution (g/tooth)	Clear aligners	10	63.1000	62.5000	8.1302	<0.001
	Conventional brackets	10	138.500	145.500	17.4308
Tooth movement efficacy (mm)	Clear aligners	10	3.1700	3.0500	0.2452	<0.001
	Conventional brackets	10	3.960	4.000	0.3471
Root resorption (mm)	Clear aligners	10	0.0390	0.0400	0.0173	<0.001
	Conventional brackets	10	0.139	0.140	0.0173
Rotation and tipping movements (%)	Clear aligners	10	93.1000	93.0000	2.0790	0.686
	Conventional brackets	10	93.500	93.500	2.2730
Patient simulation (%)	Clear aligners	10	92.2000	91.5000	3.7357	<0.001
	Conventional brackets	10	80.400	80.000	3.8355

Clear aligners demonstrated a gradual reduction in force after a 2-week period of usage, thereby necessitating the introduction of a new set of aligners to maintain the requisite force levels. In contrast, traditional brackets provided a more consistent and stable force throughout the treatment, necessitating minimal adjustments after a period of 6 weeks. The post-treatment analysis indicated negligible root resorption in both groups. Nevertheless, conventional orthodontic brackets demonstrated a slightly increased incidence of root resorption (0.139 ± 0.017), particularly in teeth that experienced substantial displacement, such as molars. This phenomenon may be attributed to the consistent force applied by the brackets, in contrast to the intermittent forces exerted by the aligners. Statistically significant differences were seen between the groups in terms of force distribution, tooth movement, root resorption, and patient simulation [Table 1 and Figure 1].

Figure 1.

Force distribution between the groups

DISCUSSION

The results of this study show that both transparent aligners and traditional orthodontics have significant benefits when it comes to moving teeth. However, the methods and effectiveness of each type of brace are noticeably different from one another. Clear aligners, like the variety, are quite good at addressing rotational and vertical motions.[3,4,5] However, they are less effective at correcting congestion and significant lateral displacements.[6] Clear aligners are more precise when it comes to controlling these motions.[7] Traditional brackets are more effective for specific dental movements, but they are also associated with a higher risk of periodontal inflammation and root resorption since they provide continuous tension.[8,9,10]

Clinicians must consider the above-noted biomechanical differences when choosing a therapy technique.This is especially important in scenarios that need a lot of side-to-side movement or where the patient’s comfort and appearance are the most important factors.[11,12] In addition, whereas in vitro studies can provide important insights, in vivo investigations are necessary to confirm these findings in real-world situations, where biological aspects such as bone remodeling and patient compliance are critical.

CONCLUSION

Effective instruments for helping teeth to move during orthodontic treatment are both clear aligners and conventional braces. Though they increase patient comfort and accuracy in targeted motions, aligners may react delayedly to complex malocclusions. Conventional braces carry more risk of root resorption and gingival irritation even if they let for faster and more forceful movement. The patient’s esthetic preferences, therapeutic needs, and specific malocclusion under treatment must all be taken into account while deciding between these two systems.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.