Comparative impact of clear aligners versus fixed orthodontic appliances on periodontal health, pain, and quality of life: a systematic review and meta-analysis

www.nature.com/bdjopen ARTICLE OPEN Comparative impact of clear aligners versus fixed orthodontic appliances on periodontal health, pain, and quality of life: a systematic review and meta-analysis Kanwalpreet Kaur1, Syed Altafuddin Quadri2, Ravinder S. Saini2, Mario Alberto Alarcón-Sánchez 3,4 and Artak Heboyan 5,6,7 ✉ 1234567890();,: © The Author(s) 2026 OBJECTIVE: Clear aligners have become a popular alternative to fixed appliances because they offer esthetic advantages and potential improvements in periodontal health and pain management while enhancing quality of life (QOL). This systematic review and meta-analysis investigated the effects of clear aligners versus fixed appliances on established outcomes. MATERIALS AND METHODS: A systematic search was conducted in PubMed, Scopus, Cochrane Library, Embase, and ScienceDirect up to March 2025, along with gray literature and manual searching of key orthodontic journals. The eligible studies consisted of randomized controlled trials and observational studies that evaluated clear aligners against fixed appliances based on the plaque index (PI), gingival index (GI), probing depth (PD), pain intensity, and QOL. Researchers applied mean difference (MD) to PI, GI, and PD, while standardized mean difference (SMD) was used to evaluate pain intensity and QOL. Researchers evaluated heterogeneity using I² and publication bias while performing subgroup analyses centered on treatment duration. RESULTS: Thirty-two studies were included in the systematic review, of which 28 were included in the meta-analysis. Clear aligners significantly improved periodontal outcomes compared to fixed appliances, as shown by lower PI scores (MD = −0.437, 95% CI: −0.507 to −0.367, p < 0.001), GI scores (MD = −0.233, 95% CI: −0.296 to −0.170, p < 0.001), and PD scores (MD = −0.332, 95% CI: −0.431 to −0.234, p < 0.001). Patients treated with clear aligners experienced less pain than those treated with fixed appliances, particularly during the early treatment phase (SMD = −0.419, p < 0.001). Clear aligners significantly improved the QOF of patients at 1 week (SMD = −0.985, p < 0.001), 1 month (SMD = −0.829, p < 0.001), and end of treatment (SMD = −0.970, p < 0.001) compared with fixed appliances. Low to moderate heterogeneity was observed between groups for pain outcomes, while high heterogeneity was observed for short-term QOF comparisons. CONCLUSION: Clear aligners resulted in favorable periodontal indices compared with those of fixed appliances. They also led to less early pain and better QOF than fixed appliances, although these differences were mostly observed at the beginning of treatment. Clinicians should interpret these results cautiously because of heterogeneity, the inclusion of observational evidence, potential publication bias, and small pooled effects. BDJ Open (2026)12:60 ; https://doi.org/10.1038/s41405-026-00450-z INTRODUCTION Esthetic concerns have become a key driver for seeking dental care, especially in orthodontics, which has evolved with advanced techniques and devices to enhance micro-, macro-, gingival, and facial esthetics, reflecting a comprehensive approach to improving dental harmony, function, and overall appearance since its establishment as a specialized branch of dentistry [1]. Orthodontic patients seek treatment not only to enhance their dental and facial esthetics but also to boost their social appeal and confidence [2–5]. Malocclusion, recognized by the WHO as a dentofacial anomaly, can impact esthetics, function, and psychosocial well-being, further reinforcing the demand for orthodontic treatment to enhance facial harmony and self-confidence [6, 7]. Defining malocclusion is challenging because perceptions of occlusal issues vary across individuals and cultures and are influenced by aesthetic preferences and functional expectations [8]. Malocclusion commonly arises during the transition to mixed dentition, leading to speech difficulties, eating challenges, facial structural changes, and tongue or cheek biting [9]. This condition is traditionally managed using braces, which are available in various materials, including metal, ceramic, stainless steel, and gold [9, 10]. Conventional metal braces consist of brackets affixed to the teeth 1 Rutgers School of Dental Medicine, Newark, NJ, USA. 2Department of Allied Dental Health Sciences, College of COAMS, King Khalid University, Abha, Saudi Arabia. 3Molecular Biology and Medicine Program, University Center for Health Sciences, University of Guadalajara (CUCS-UdeG), Guadalajara, Mexico. 4Department of Integral Dental Clinics, Institute of Research in Dentistry, University Center of Health Sciences, University of Guadalajara (CUCS-UdeG), Guadalajara, Mexico. 5Department of Research Analytics, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, India. 6Faculty of Stomatology, Department of Prosthodontics, Yerevan State Medical University after Mkhitar Heratsi, Yerevan, Armenia. 7Department of Prosthodontics, School of Dentistry, Tehran University of Medical Sciences, North Karegar St., Tehran, Iran. ✉email: Received: 2 January 2026 Revised: 24 April 2026 Accepted: 29 April 2026 K. Kaur et al. 2 and connected by an arch wire that exerts controlled pressure to facilitate alignment but provides minimal cosmetic advantages [11, 12]. Ceramic braces function similarly but are designed to match the natural tooth color for enhanced esthetics [13]. For patients prioritizing discretion, lingual braces offer an alternative by positioning the brackets on the lingual rather than buccal surfaces, which may reduce pain compared to pre-fabricated ones; however, patients often experience greater difficulties with speech and mastication when using lingual appliances [14]. Despite their various advantages, these materials have significant flaws, including poor esthetics and higher modulus of elasticity in stainless steel brackets, fragility and staining in ceramic brackets, lack of stiffness and deformation issues in plastic brackets, mechanical complexity and potential breakage in self-ligating brackets, speech disruption and plaque-related gingival irritation in lingual brackets, reduced accuracy in butterfly systems, and discoloration in brackets [13]. Alternatively, Clear aligners have revolutionized orthodontic treatment since their introduction in 1999, offering a compelling alternative to traditional braces [15]. Their nearly invisible appearance has expanded treatment accessibility, particularly among image-conscious adults [16]. The clinical decision between fixed appliances and clear aligners increasingly relies on evidence-based comparisons of the key outcomes. The evaluation of orthodontic treatment modalities extends beyond traditional measures of occlusal correction to encompass a broader spectrum of clinical and patient-cantered outcomes. The plaque index (PI) serves as a critical measure of oral hygiene maintenance (...truncated)