Original Research

Year : 2026 | Volume : 17 | Issue : 2 | Page : 29-42

Comparison of Heat-Activated Copper Nickel-Titanium and Multistranded Stainless Steel Archwires on Pain Perception and Alignment Efficiency: A Randomized Clinical Trial

Sobitha Obili-1, Gowri Sankar Singaraju-2, Venkatesh Nettam-3, Ravindra Vangala-4, Prasad Mandava-5

1-Postgraduate Resident, 2-Professor, 3-Associate Professor, Department of Orthodontics, Narayana Dental College, Nellore, 4-Professor and Head, Gitam Dental College and Hospital, Visakhapatnam, Andhra Pradesh , 5-Professor and Head, Department of Orthodontics, Narayana Dental College , Nellore, Andhra Pradesh, India -524003.

Address for Correspondence:

Dr Prasad Mandava

Professor and Head,

Department  of Orthodontics, Narayana Dental College,

Nellore, Andhra Pradesh, India -524003.

Email :mandavabruno9@gmail.com

ORCID ID:0000-0003-3024-544X

ABSTRACT

BACKGROUND: The initial archwires during the alignment phase must be effective and cause as little pain as possible for the patient. There is limited information that compares heat-activated copper nickel-titanium (CuNiTi) and multistranded stainless steel archwires.

OBJECTIVES: This study aims to compare the impact of 0.016-inch copper-nickel-titanium (CuNiTi) archwires and 0.0175-inch multistranded stainless steel archwires on alignment efficiency, changes in transverse dimensions, and pain perception during the initial phase of treatment.

METHODS: This randomized clinical trial included 48 subjects, of whom 32 completed the study. Participants were allocated to receive either 0.016-inch CuNiTi or 0.0175-inch multistranded stainless steel archwires. Alignment was assessed using Little’s Irregularity Index, and transverse dimensions were measured on dental casts at baseline (T0) and 6 weeks (T6). Pain was evaluated using a 10-point visual analogue scale at T1 (4 h), T2 (24 h), T3 (3 d), T4 (7 d), T5 (30 d), and T6 (6 wks.). Statistical analysis included independent paired t-tests, Mann–Whitney U test, and Friedman test.

RESULTS:  CuNiTi archwires demonstrated greater alignment reduction at 6 weeks (3.55 ± 0.39 mm vs 2.55 ± 0.78 mm; p = 0.0001), while intercanine width increased more with multistranded SS (0.84 ± 0.26 mm vs 0.64 ± 0.11 mm; p = 0.0105). Regarding pain, CuNiTi caused higher scores at 4 hours (4.19 ± 1.67 vs 2.44 ± 0.79; p = 0.001).

CONCLUSION: Within the limitations of this short-term study, CuNiTi showed greater early alignment reduction, while pain differences were transient. Both archwire systems are clinically useful, and selection should be guided by crowding severity, patient comfort, and cost-effectiveness.

CLINICAL TRIAL REGISTRATION: CTRI/2021/02/031065

KEYWORDS: Orthodontic Wires; Nickel-Titanium Alloys; Multistranded; Pain; Alignment

CONFLICT OF INTEREST AND FUNDING

Nil

How to cite this article: Sobitha Obili, Gowri Sankar Singaraju, Venkatesh Nettam, Ravindra Vangala, Prasad Mandava. Comparison of Heat-Activated Copper Nickel-Titanium and Multistranded Stainless Steel Archwires on Pain Perception and Alignment Efficiency: A Randomized Clinical Trial. Int J Orthod Rehabil 2026; 17 (2): 29-42.

Doi: 10.56501/Intjorthodrehabil.172.ijor0096

Review Article

Year : 2025 | Volume : 16 | Issue : 4 | Page : 14-38

Antimicrobial, Biocompatibility, and Durability Outcomes of Nanoparticle-Coated Orthodontic Materials: A Systematic Review of In Vivo Evidence

Avula Samata1, Gowri Sankar Singaraju2, Prasad Mandava2, P V Sravya Silpa1

1-Postgraduate Resident, 2-Professor, Department of Orthodontics, Narayana Dental College, Nellore, Andhra Pradesh, India-524003
Address for Correspondence:

Dr. Prasad Mandava,

Professor and Head, Department of Orthodontics,

Narayana Dental College,

Nellore, Andhra Pradesh, India -524003.

Email ID: mandavabruno9@gmail.com

ABSTRACT

Objective: To systematically review available in vivo evidence from animal and human studies evaluating the antimicrobial efficacy, biocompatibility, and durability of metallic nanoparticle-coated orthodontic materials, excluding all in vitro research.

Methods: Electronic searches were performed in PubMed/MEDLINE, Scopus, Web of Science, Cochrane Library, Ovid, and ClinicalTrials.gov for studies published from January 2015 to August 2025, supplemented by manual and grey-literature searches. Eligible studies included in vivo animal or human investigations assessing surface coatings of orthodontic components—brackets, archwires, ligatures, elastomeric modules, or aligners—with metallic or metal-oxide nanoparticles (Ag, TiN, TiO₂, N-TiO₂, ZnO, Au). Primary outcomes were antimicrobial efficacy (CFU, qPCR, or biofilm indices); secondary outcomes included biocompatibility (ion release, cytotoxicity, mucosal response) and coating durability. Quality appraisal used SYRCLE, RoB 2, and ROBINS-I tools; evidence certainty was graded using GRADE. Registration: OSF (https://doi.org/10.17605/OSF.IO/5CZSG).

Results: Of 1,499 records, eight in vivo studies met the inclusion criteria—six human and two animal. Nanoparticles evaluated were Ag, TiN, TiO₂, N-TiO₂, ZnO, and Au. All demonstrated reduced Streptococcus mutans or related bacterial loads compared with uncoated controls. Silver coatings produced early antibacterial effects but released trace Ag⁺ (0.16–0.35 ppb). TiO₂ and TiN coatings reduced bacterial adhesion up to four weeks but showed partial delamination (~60%). N-doped TiO₂ extended efficacy to 60 days, while ZnO coatings-maintained suppression and enamel protection for 12 months despite early surface degradation. Gold nanoclusters exhibited short-term antibacterial and excellent biocompatibility in animal models. Biocompatibility was acceptable across studies, but durability and long-term stability were inconsistently assessed. Meta-analysis was precluded by heterogeneity of outcomes and timepoints. Overall risk of bias ranged from low to serious; certainty of evidence was low to moderate.

Conclusions: In vivo data indicate short-term antibacterial and biocompatible benefits of metallic nanoparticle coatings on orthodontic materials; however, evidence for coating durability and long-term safety is limited. Well-designed randomized clinical trials with standardized microbial, biocompatibility, and durability outcomes are essential for clinical translation.
Keywords: Metallic nanoparticles; Orthodontic materials; Antimicrobial; Biocompatibility; Durability; In vivo; Systematic review.

CONFLICT OF INTEREST

The authors have no conflict of interests to declare.

FUNDING

Nil.
How to cite this article: Avula Samata, Gowri Sankar Singaraju, Prasad Mandava, P V Sravya Silpa. Antimicrobial, Biocompatibility, and Durability Outcomes of Nanoparticle-Coated Orthodontic Materials: A Systematic Review of In Vivo Evidence. Int J Orthod Rehabil 2025; 16 (4): 14-38.