Clear aligners: between clinical inertia and dormant disruption.

Background: Clear aligner therapy (CAT) has become increasingly popular for treating mild to moderate malocclusions. However, discrepancies between predicted and achieved tooth movement remain a concern, partly due to the limited understanding of aligner material behavior under clinical conditions. Since these materials must deliver controlled and sustained forces, their flexural properties are critical for treatment efficacy. Objective: To identify and analyze in vitro studies investigating the flexural properties of thermoplastic clear aligner materials, summarize their testing methodologies, and examine the factors that may influence their clinical performance. Methods: A scoping review was conducted following the PRISMA-ScR guidelines. Three electronic databases (PubMed, Scopus, and Web of Science) were systematically searched. Studies were screened based on predefined eligibility criteria, and data extraction included testing methods, materials, and clinically relevant variables. Risk of bias was assessed using the QUIN tool. Results: Seventeen studies published between 2008 and 2024 were included. All studies used three-point bending to assess mechanical properties. Common influencing factors included thermoforming, liquid absorption, temperature changes, loading conditions, and material thickness. Most studies reported that these factors negatively affected force delivery. The most frequently tested material was Duran (PET-G). Polyurethane-based materials, such as Zendura, showed comparatively better stress relaxation properties. Conclusions: Thermoforming, intraoral temperature changes, liquid exposure, and prolonged or repeated loading can compromise the mechanical properties and force delivery capacity of aligner materials. Standardized testing methods and further investigation of newer materials are essential to enhance the predictability and performance of clear aligner therapy.

The teaching of orthodontics: An historical introduction

Advances in orthodontic clear aligner materials.

Lateral cephalograms have the inherent drawback of superimposition of bilateral structures, while landmarks are more reproducible on CBCT scans. Yet no studies in the literature have utilized 3D imaging to investigate the effects of clear aligners on anterior open bite. Therefore, The aim is to measure the skeletal and dental changes that contribute to anterior open bite closure with clear aligner therapy on CBCT scans. It is a single-arm retrospective study that included 40 cases of anterior open bite who were treated using Invisalign. Pre- and post-treatment CBCT scans were traced to record 13 dental and 3 skeletal measurements. A paired t-test was conducted to compare the mean values of pre- and post-treatment measurements. Combined intrusion of the maxillary right and left molars was statistically significant, meanwhile mandibular molars maintained their vertical position. Maxillary incisors were extruded and retroclined significantly, whereas mandibular incisors were only extruded. While anterior facial height was decreased insignificantly, both lower anterior facial height and mandibular plane angle showed a significant decrease. Clear aligner (Invisalign) therapy is effective in the management of anterior open bite through vertical control, maxillary molars intrusion, maxillary incisors extrusion, maxillary and mandibular incisors retroclination, and mandibular autorotation.

BackgroundThe introduction of auxiliaries such as composite attachment has improved the force delivery of clear aligner (CA) therapy. However, the placement of the attachment may give rise to a flash, defined as excess resin around the attachment which may affect CA force delivery. This in vitro study aims to determine the differences in the force generated by the attachment in the presence or absence of flash in CA.Materials and methodsTristar Trubalance aligner sheets were used to fabricate the CAs. Thirty-four resin models were 3D printed and 17 each, were bonded with ellipsoidal or rectangular attachments on maxillary right central incisors. Fuji Prescale pressure film was used to measure the force generated by the attachment of CA. The images of colour density produced on the films were processed using a calibrated pressure mapping system utilising image processing techniques and topographical force mapping to quantify the force. The force measurement process was repeated after the flash was removed from the attachment using tungsten-carbide bur on a slow-speed handpiece.ResultsThe intraclass correlation coefficient showed excellent reliability (ICC = 0.96, 95% CI = 0.92–0.98). The average mean force exerted by ellipsoidal attachments with flash was 8.05 ± 0.16 N, while 8.11 ± 0.18 N was without flash. As for rectangular attachments, the average mean force with flash was 8.48 ± 0.27 N, while 8.53 ± 0.13 N was without flash. Paired t-test revealed no statistically significant difference in the mean force exerted by CA in the presence or absence of flash for both ellipsoidal (p = 0.07) and rectangular attachments (p = 0.41). Rectangular attachments generated statistically significantly (p < 0.001) higher mean force than ellipsoidal attachments for flash and without flash.ConclusionAlthough rectangular attachment generated a significantly higher force than ellipsoidal attachment, the force generated by both attachments in the presence or absence of flash is similar (p > 0.05).

The rising demand for aesthetic and comfortable orthodontic treatments has led to the widespread use of clear aligner therapy (CAT), a modern alternative to traditional braces. This umbrella review examines the biological effects of bisphenol A (BPA), a synthetic compound commonly found in clear aligner materials, focusing on its potential health risks. BPA is known for its estrogen-mimicking properties and has been associated with endocrine disruption and increased cancer risk. This review synthesizes findings from systematic reviews and meta-analyses to evaluate BPA leaching in aligner therapy and its implications for patient safety. A total of 25 studies were screened, with three high-quality systematic reviews included in the final analysis. In vitro studies generally reported minimal cytotoxicity and weak estrogenic effects, while clinical trials suggested higher BPA levels due to the dynamic oral environment. Risk of bias was assessed, and forest and funnel plots indicated consistent findings with low immediate toxicity but raised concerns regarding long-term hormonal effects. Given these findings, further research is recommended to assess BPA exposure under real oral conditions and to develop BPA-free aligner materials. This review underscores the importance of biocompatibility in orthodontic materials and the need for rigorous safety assessments to protect patient health.

Objectives: Over the last two decades, clear aligners have become a mainstay in contemporary orthodontic practice primarily due to improvements in digital and 3D printing technologies, a growing interest in esthetic orthodontics, especially in the adult population, and aggressive manufacturer marketing internationally. Material and Methods: PubMed, Google Scholar, Cochrane Library, and EMBASE databases were searched from January 1998 to November 2021. The search terms used were “Invisalign” OR “clear aligner.” A total of 7000 records were searched, of which 369 potentially relevant articles were retrieved in full. 190 studies met the selection criteria following screening and were included in the scoping review. Results: This review scopes and analyses published orthodontic literature about CA according to a year-wise distribution into 3 groups, 2001–2010/2011–2020/2021. Most of the studies were published in the period between 2011 and 2020, with 138 studies accounting for 73%. The year 2021 followed, with 31 studies accounting for 16%, which was greater than the number of studies published in 10 years from 2001 to 2010. Studies were also classified based on the study designs with most of the published studies representing the lowest level of evidence including case reports, case series, narrative reviews, expert opinions, and editorials accounting for 137 studies, whereas case-control studies were the least reported studies with only 4 studies reported in the literature. In addition, they were categorized into seven main domains: (1) Biological considerations associated with clear aligner therapy (CAT), (2) Treatment outcomes considerations associated with CAT, (3) Geometrical considerations associated with CAT (clinical), (4) Biomechanical considerations associated with CAT (Laboratory/Finite element analysis), (5) Biomaterial considerations associated with CAT, (6) Patient education and experience and aesthetic and social perception of CAT, and (7) Miscellaneous. Treatment outcome considerations associated with CAT had the greatest percentage representing 36% of the total published domains, while the final place was occupied by the biomechanical considerations associated with CAT accounting for only 4% of the published domains about CAT. Conclusion: Treatment outcome was the domain most commonly reported by studies accounting for (36%). Most of the published studies are at the lowest level of evidence including case reports, case series, narrative reviews, and expert opinions. The vast majority of studies utilized only a single clear aligner brand. There is a greater need for research that studies CAT from a holistic perspective.

Background: Clear aligner (CA) therapy has been increasingly adopted as an alternative to fixed orthodontic appliances. However, evidence regarding its periodontal effects, including gingival inflammation, biofilm composition, and the potential role of aligner marginal edge design, remains insufficiently mapped. The objective of this scoping review was to map and synthesize available clinical and laboratory evidence on periodontal and biological outcomes associated with CA therapy, with particular attention to the potential influence of aligner marginal edge design. Methods: This scoping review followed PRISMA-ScR and the Population-Concept-Context (PCC) framework. PubMed, Scopus, and Web of Science were searched from 1 January 2015 to 24 October 2025. A total of 1587 records were identified; after deduplication, 770 unique records were screened by title and abstract, followed by full-text assessment of potentially eligible articles. Twenty-five primary studies published between 2020 and 2025 met eligibility criteria and were included in the review. Results: The final synthesis comprised clinical investigations, laboratory studies, and case reports. Clinical periodontal indices and inflammatory biomarkers were assessed using heterogeneous protocols and timepoints. Only three studies specifically addressed aligner marginal edge design; one directly compared margin configurations, reporting differences in local gingival response, with substantial diversity in study design precluding quantitative synthesis. Conclusions: Available evidence on periodontal outcomes during CA therapy is methodologically heterogeneous. Investigations of aligner marginal edge design remain scarce. Standardized assessment protocols and targeted clinical studies are needed to establish the periodontal relevance of trimline configurations.

Digital treatment planning software in clear aligner (CA) therapy incorporates virtual simulations to generate planned tooth movements. While baseline tooth positions constitute one of the geometric inputs to digital setups, limited information is available regarding the association between pre-treatment positional asymmetry and the magnitude of planned movements, and how these associations vary by tooth and movement type. A retrospective analysis was conducted on 65 patients (390 anterior teeth) treated with Invisalign®. Baseline malpositions of anterior teeth were measured using 3D digital models in ClinCheck®, while planned movements-including rotation, angulation, extrusion, and intrusion-were extracted from the corresponding digital treatment plans. Baseline asymmetry between contralateral teeth was calculated to quantify movement complexity. General Linear Model (GLM) regression analyses were employed to assess the relationship between initial asymmetry and the magnitude of planned movements. Descriptive statistics and normality assessments were also performed. In the 11-21 tooth pair, baseline asymmetry was significantly associated with planned extrusion (p = .002) and rotation (p < .001), but not intrusion (p = .190) or angulation (p = .270). For the 12-22 pair, significant associations were observed for intrusion (p = .008), angulation (p < .001), and rotation (p < .001), but not extrusion (p = .493). In the 13-23 pair, only extrusion was significantly associated with baseline differences (p < .001); no significant effects were observed for the other movement types. Baseline positional asymmetry was associated with variation in planned extrusion, intrusion, and rotation movements within digital CA setups. These findings should be interpreted as descriptive associations rather than evidence of software-imposed constraints or internal planning strategies, and underscore the relevance of baseline geometry when interpreting digitally planned tooth movements.

BackgroundClear aligner therapy is gaining traction owing to its esthetics and comfort. Although most aligners use thermoforming, 3D printing offers advantages such as higher accuracy and reduced waste. While literature on the properties of some 3D-printed aligner materials compared to thermoformed ones is available, a comprehensive study is currently lacking that compares all three materials (iLuxclear (LC), Graphy Clear Aligner (GY), and RightBio Clear Aligner (RD)) with thermoformed materials, particularly regarding optical and biofilm adhesion characteristics.MethodologyThree 3D direct-printed materials (LC, GY and RD) and two thermoformed materials (easyDu (ED) and Biolon (SC)) were tested. Surface morphology was analyzed by stereomicroscopy. Surface roughness (Ra) was measured at baseline (0 day) and after 45 days of immersion in artificial saliva. Light transmittance and color stability (ΔE00) were evaluated after 7 and 14 days of aging in saliva, black tea, and coffee. Bacterial adhesion was quantified using Streptococcus mutans (S. mutans) at baseline and after 3 and 7 days.ResultsThe 3D direct-printed aligners, particularly the LC group, exhibited increased surface morphology irregularities and significantly higher Ra values than the thermoformed materials; Ra increased after 45 days of immersion in artificial saliva across all groups. The thermoformed materials maintained stable color integrity, while the 3D-direct printed materials varied in performance. GY demonstrated a uniform surface structure, lower roughness, and the highest color stability, whereas LC and RD experienced significant discoloration. The RD group exhibited significantly higher S. mutans adhesion, whereas the thermoformed materials exhibited superior biofilm resistance. Notably, GY achieved comparable S. mutans adhesion to the thermoformed materials after a 7-day culture.ConclusionsAmong the 3D direct printed aligners, GY achieved comparable surface and microbiological performance to conventional options. These findings underscore their potential for balancing esthetics, susceptibility to bacterial adhesion, and clinical performance in clear aligner therapy.

ABSTRACTBackgroundBruxism is a masticatory muscle activity that may occur during sleep (SB) or wakefulness (AB) and is not classified as a movement or sleep disorder. Clear aligner therapy, widely adopted as a removable and aesthetic orthodontic alternative, modifies occlusal contacts and mandibular dynamics, which may influence the occurrence or perception of bruxism behaviours.ObjectiveTo systematically review the association between clear aligner therapy and bruxism (SB, AW and mixed/self‐reported), with a focus on evaluating its role as neutral, protective or a potential risk factor.MethodsA systematic search of electronic databases and grey literature was conducted through April 2025, with included studies that identified bruxism using validated instrumental methods (portable electromyography for SB, or smartphone‐based ecological momentary assessment for AB), subjective questionnaires on behaviours and related symptoms. Risk of bias was assessed using the Joanna Briggs Institute tool, and evidence quality was evaluated with GRADE.ResultsEleven studies evaluated 818 patients (72.8% female). Most studies suggested a neutral effect of clear aligners on bruxism. For SB, aligners often reduced tonic contractions but showed inconsistent effects on higher phasic activity and no changes on overall SB index. AB was generally unaffected, though one study reported reduced self‐reported parafunctions with altered muscle recruitment. Mixed/self‐reported bruxism outcomes were conflicting: some studies indicated improvements in clenching and TMJ pain, while others found a higher prevalence of bruxism symptoms during aligner therapy. Methodological heterogeneity and risk of bias were notable, precluding that no meta‐analysis was possible. GRADE certainty for randomised studies was moderate and very low for non‐randomised studies.ConclusionCurrent evidence on the relationship between clear aligner therapy and bruxism remains limited and heterogeneous. Most studies suggest a neutral effect, with occasional reductions in tonic contractions or symptom improvement, but also reports of increased phasic activity or self‐reported bruxism. Overall, aligners cannot yet be classified as protective or harmful, highlighting the need for standardised, high‐quality studies to clarify their role in bruxism management.

Management of the anterior open bite using clear aligner therapy and surgery-first: Case example and scoping review of the literature

Clear Aligners are becoming popular among patients in recent years because of its invisible nature , comfort to wear, less orthodontic emergencies and better hygiene control. However proper case selection is vital for the success. With the better understanding of aligner biomechanics and improvement in aligner materials and attachment design, more complex teeth movement is also possible with clear aligners. As there is always controversy on whether aligners cause tipping or bodily tooth movement, In this case report, a skeletal class I patient with generalized spacing in maxilla and mandible is presented which is treated effectively by bodily movement of incisors.

In recent years, clear aligners have become a well-liked substitute for traditional braces in orthodontic treatment. Examining the effects of clear aligners on periodontal health and plaque accumulation is the goal of this review. To examine pertinent studies that have been published up to this point, a comprehensive evaluation of the literature was carried out. The review includes research on the microbial alterations in tooth plaque composition that occur during clear aligner therapy and the subsequent impact on periodontal tissues. Clear aligners and traditional braces are also compared with respect to how they affect gingival health, periodontal disease prevalence, and oral hygiene practices.In terms of plaque control, the results imply that transparent aligners offer special benefits and challenges. An important factor influencing the microbiological environment in the oral cavity is patient compliance, the type of aligner used, and the subtleties of its design. Moreover, the effect of orthodontic therapies on periodontal health is explored, providing insight into possible associations between the use of clear aligners and periodontal results. By underlining the necessity of individualized oral hygiene management strategies during clear aligner therapy, this review offers orthodontic practitioners’ insightful information. It highlights the need of maintaining periodontal health throughout orthodontic treatment and stresses the necessity of a multidisciplinary approach to optimize patient outcomes. In summary, this comprehensive review provides an overview of the most recent findings regarding the impact of clear aligners on plaque and periodontal health. By teaching clinicians, researchers, and patients about the subtleties of oral hygiene care during orthodontic treatment, the findings are meant to direct the development of effective strategies for maintaining good periodontal health in patients getting clear aligner therapy.

Clear aligner therapy has an aesthetic advantage over fixed appliance therapy. However, to our knowledge, no study has objectively compared patient orthodontic and aesthetic outcomes between clear aligner and fixed appliance therapies administered after orthognathic surgery (OGS). This study included patients with no history of congenital craniofacial deformities who underwent surgery-first OGS and received clear aligner or fixed appliance therapy. The patients' grades on the Dental Health Component (DHC) and Aesthetic Component of the Index of Orthodontic Treatment Need and scores on the Peer Assessment Rating (PAR) index were calculated before OGS (T0), after OGS (T1), and after orthodontic therapy (T2). This study included 33 patients (clear aligner therapy, n = 19; fixed appliance therapy, n = 14). No considerable between-group differences were noted in the DHC and AC grades at T0, T1, or T2. Furthermore, percentage of reduction in the PAR index score was more significant in the clear aligner group (74.4%) than in the fixed appliance group (63.2%) from T0 to T1 ( P = 0.035); however, no between-group differences were noted from T1 to T2 or from T0 to T2. Both groups exhibited substantially improved DHC grades, Aesthetic Component grades, and PAR index scores at T1 and T2. Patient outcomes were similar between the clear aligner and fixed appliance groups after orthodontic therapy. However, the former group exhibited more favorable immediate results after OGS than did the latter group. Thus, as an adjunct therapy for patients with malocclusion, clear aligner therapy may be more effective than fixed appliance therapy. Therapeutic, II.