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 Table of Contents  
Year : 2023  |  Volume : 15  |  Issue : 1  |  Page : 1-7

Antibacterial activity of nanoparticle-coated orthodontic archwires: A systematic review

Department of Orthodontics, Saveetha Dental College and Hospital, Saveetha Institute of Medical and Technical Sciences, Chennai 600077, Tamil Nadu, India

Date of Submission18-Jul-2022
Date of Decision10-Oct-2022
Date of Acceptance10-Oct-2022
Date of Web Publication28-Feb-2023

Correspondence Address:
Dr. Remmiya M Varghese
Department of Orthodontics, Saveetha Dental College and Hospital, Saveetha Institute of Medical and Technical Sciences, Chennai 600077, Tamil Nadu
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jioh.jioh_152_22

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Aim: The purpose of this review is to conduct a systematic assessment of the literature and report on the antibacterial activity of nanoparticle-coated orthodontic archwires. Materials and Methods: A systematic search of the following scientific databases PubMed, Google Scholar, SCOPUS, LILACS, and Cochrane CENTRAL was performed to identify relevant articles that were published until December 2021. Articles satisfying the eligibility criteria were included in the review process. Methodological evaluation was done to determine the methodological quality of the included studies. The data of antibacterial activity evaluated by the studies were extracted. Results: A total of five studies were included in the qualitative analysis. All of the included studies showed that nanoparticle-coated orthodontic archwires showed good antibacterial activity when compared with uncoated control archwires. The overall methodological quality of the included studies was assessed to be moderate. Conclusion: Qualitative assessment of the available literature suggests a significant in-vitro antibacterial activity of orthodontic archwires that were subjected to surface modification by nanoparticle coating.

Keywords: Anti-adherent, Antibacterial, Nanoparticle, Plaque

How to cite this article:
Maliael MT, Varghese RM, Subramanian AK. Antibacterial activity of nanoparticle-coated orthodontic archwires: A systematic review. J Int Oral Health 2023;15:1-7

How to cite this URL:
Maliael MT, Varghese RM, Subramanian AK. Antibacterial activity of nanoparticle-coated orthodontic archwires: A systematic review. J Int Oral Health [serial online] 2023 [cited 2023 Mar 23];15:1-7. Available from:

  Introduction Top

The mouth hosts a number of microorganisms and provides them with an environment for their proliferation. These microbes, primarily bacteria, produce substrates that are capable of demineralizing enamel. A disease-free environment is maintained by a balancing act between the cleansing action of the saliva buffer and the microbial substrates. The introduction of orthodontic appliances greatly affects the balance as it offers the perfect environment for microbial colonization. Owing to the intrinsic morphological and surface imperfections of fixed appliances, plaque collection and retention are increased which in turn increase the risk of enamel demineralization and gingival inflammation adjacent to the appliance.[1],[2],[3],[4],[5] This impact also tends to exacerbate the effects of incipient carious lesions. The effects of enamel demineralization are visible in patients who are less than 4 weeks into the start of their orthodontic treatment.[6],[7],[8],[9],[10]

Among the various components of fixed appliances, wires have shown to play a major role in the onset of enamel demineralization. Contact points between the wire and the bracket provide an excellent environment for colonization of pathogenic bacteria as it impedes access to various tooth surfaces for the maintenance of oral hygiene. Eliades et al.[11] observed that stainless steel has the highest critical surface tension and energy. This translates into higher plaque accumulation and retention, especially in stainless steel brackets. Stainless steel has also shown to induce pH changes in the oral environment[1],[12],[13] and increase the chances for colonization of cariogenic bacteria Streptococcus mutans and Lactobacillus acidophilus.[14] Preventing enamel demineralization and the reduction in the incidence of white-spot lesions are of prime importance for the orthodontist as the end result of these lesions is unaesthetic and irreversible.

Surface modification is one of the ways through which the surface topography of the orthodontic archwires can be altered. According to various authors, this form of surface alteration of the orthodontic archwire reduces the tendency for bacterial adhesion, and depending on the coating material used, antibacterial activity can also be seen.[15],[16],[17],[18],[19],[20],[21],[22]

Nanoparticles (np) are particles of matter of size ranging from 1 to 100 nm in diameter.[23] These particles gained mainstream attention in the 1990s through the establishment of the National Nanotechnology Initiative in the USA.[24] These particles have been extensively studied and researched for their properties and possible applications. These particles are insoluble in water, and some authors have examined the utilization of these particles to coat orthodontic appliances to improve their antibacterial properties.[25],[26],[27] Different techniques such as physical vapor deposition, electrodeposition, and so on can be used to coat such nanoparticles onto orthodontic appliances.[21] A few studies have observed an improvement of antibacterial properties of np-coated orthodontic archwires without any compromise in their mechanical and tribological properties of the wires.[28],[29] There are, however, no systematic reviews till date reporting about the antibacterial activity of np-coated archwires. Validation of the antibacterial activity of the np-coated archwires is required to employ them in clinical practice.


The objective of the current systematic review is to critically evaluate and assess the available evidence on the antibacterial activity of nanoparticle-coated orthodontic archwires.

  Materials and Methods Top


The review was prepared adhering to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRSIMA) guidelines. The protocol for this review was not registered in any database.

Eligibility criteria

Studies reporting on antibacterial activity of np-coated orthodontic wires compared with uncoated orthodontic archwires were included in this review. The PICOS for the review [Table 1] is as follows:
Table 1: Eligibility criteria for studies included in this review

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Population—Orthodontic archwires

Intervention—Nanoparticle-coated orthodontic archwires

Control—Non/uncoated orthodontic archwires

Primary outcome—Antibacterial activity

Secondary outcome—Anti-adherent activity

Study design—In-vitro studies

Information sources, search strategy, and study selection

The following scientific databases PubMed, Google Scholar, Cochrane Library, Scopus, and LILACS were searched systematically to identify all peer-reviewed articles published from 1990 to December 2021 pertinent to the review’s question. Considering the varying vocabulary and syntax limitations of each database, a detailed search strategy was developed for each database. The keywords used for the search in each database are presented in [Table 2]. Additionally, orthodontic journals of interest were searched to identify any further studies. A search was also conducted on the following scientific databases OpenGrey and GreyNet International to identify any gray literature. References of the included studies in the review were also searched to identify any studies that could be included in the review. Language constraint was applied to the data search process, and only articles published in English or those with an accompanying English translation were taken into consideration for inclusion in the review.
Table 2: Search strategy used in the various databases

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Two reviewers (MTM, RMV) conducted the search independently, and any differences of opinion among the primary reviewers were settled in consultation with an independent reviewer (AKS) who was not involved in the search process. Only published papers were taken into consideration for the evaluation in the review. The review’s inclusion and exclusion criteria are described in [Table 1].

Data collection process

Studies that met the selection criteria were included in the review process for evaluation. The PRISMA flow chart depicts the review’s selection procedure [Figure 1]. A characteristic table of the included studies was prepared with the following details: first author, year of publication, research design, sample size, and outcomes (i.e., parameters assessed) [Table 3].
Figure 1: PRISMA flow chart depicting the study selection process

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Table 3: Characteristics and results table

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Quality assessment of the included studies

The included studies were evaluated qualitatively using a methodological evaluation described by Ehsani et al.[30] [Figure 2]. A scoring system based on this key article was developed with a maximum score of 15. The scoring scale used in the review categorized studies with a good quality of methodology having a total score between 11 and 15, studies with a moderate quality of methodology having a total score between 6 and 10, and studies with a poor quality of methodology having a total score between 0 and 5.
Figure 2: Methodological evaluation as described by Ehsani et al.[30]

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  Results Top

Determination of relevance, validation, and data extraction

After thorough search of the various scientific databases and gray literature sources, 441 studies in total were found. After elimination of duplicates by manual screening, 360 studies remained. After screening the titles and abstracts for eligibility, 350 studies were eliminated. Full-text was retrieved for the remaining 10 studies. After careful assessment of full text, five studies were eliminated as they failed to meet the eligibility criteria.[29],[31],[32],[33],[34] The remaining five studies were included for qualitative analysis.[35],[36],[37],[38],[39] Due to the major differences in the methodology of the included studies for qualitative analysis, it was decided not to perform a quantitative analysis. A manual search of the references of the included studies did not identify any further studies that could be included in the review process.

Data items and collection

Detailed data regarding the study, its outcomes, and results were extracted and tabulated into the characteristics table [Table 3].

Quality assessment of the included studies

Based on the methodological evaluation as given by Ehsani et al.[30] [Figure 2], quality of evidence of the included studies was assessed [Table 4]. Three studies included in the qualitative analysis had shown good quality of methodology,[35],[36],[37]and the remaining two studies had a moderate quality of methodology.[38],[39] The overall quality of the methodology of the included studies was determined to be moderate.
Table 4: Methodological quality assessment of included studies

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Results of individual studies

The studies by Hammad et al.,[35] Mhaske et al.,[36] Kachoei et al.,[37] and Espinosa-Cristόbal et al.[38] have observed that np-coated orthodontic archwires show a good antibacterial activity in comparison to uncoated control orthodontic archwires. The study by Gonçalves et al.[39] in their results observed that significant difference in antibacterial and anti-adherent activity was seen only in np-coated orthodontic archwires from Brand 1. This difference in antibacterial and anti-adherent activity was not seen in np-coated wires from Brand 2. Anti-adherent activity was also examined by Espinosa-Cristόbal et al.[38] and Mhaske et al.[36] Both these studies identified a significant anti-adherent activity in np-coated orthodontic archwires. The study by Espinosa-Cristόbal et al.[38] also evaluated the effect of size of np in their antibacterial activity and anti-adherent activity and observed that the smaller size np (8.1 nm) had better activity when compared with that of the larger particle (20.1 nm) [Table 5].
Table 5: Results table

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  Discussion Top

Orthodontic wires offer a great site for bacterial colonization. These bacteria are primarily to blame for plaque buildup and the subsequent onset of white-spot lesions. The antibacterial properties of nanoparticles have been utilized to reduce the extent of bacterial colonization. The studies included in the qualitative analysis have reported a good antibacterial and anti-adherent activity in np-coated orthodontic archwires.

The major methodological difference among the studies included in this review was in the techniques used to evaluate the antibacterial activity of np-coated orthodontic archwires. The studies utilized zone inhibition, chemical indicators, biofilm formation, and colony-forming units to assess the antibacterial activity. This variability could have a confounding effect as there is no standardized assessment among the studies included in the review. This heterogeneity limited the scope of this study to just a qualitative analysis.

Three of the included studies have reported the number of samples evaluated for their antibacterial activity.[35],[36],[37] Thus, these studies were identified to have a good quality of methodology based on the criteria used in the review. The remaining two studies have not reported the number of samples evaluated,[38],[39] and these studies were assessed to have a moderate quality of methodology by the criteria used in the review. None of the included studies have done any prospective calculation of the sample size. Therefore, it becomes difficult to ascertain whether the sample size evaluated is sufficient to assess the outcomes. The overall quality of methodology was thus assessed to be moderate.

The study by Gonçalves et al.[39] evaluated uncoated and surface-modified wires of two different brands. They observed that there was significant difference in the antibacterial activity among the surface-modified and control wires of Brand 1, but the same observation was not seen for wires from Brand 2. The study by Espinosa-Cristóbal et al.[38] is the only study included in the qualitative analysis in which the effect of size of nanoparticle on the antibacterial activity of np-coated wires was assessed. They observed that the smaller-sized (8.1 nm) nanoparticles exhibited significantly (P < 0.05) better antibacterial activity when compared with that of the larger-sized nanoparticles (20.1 nm). They hypothesize that this could be due to smaller-sized nanoparticles having more surface area when compared with the larger nanoparticles.

The included studies have also used different techniques to modify the surface of the archwire and have claimed that the specific technique used in their study is better and advantageous, although this review cannot independently ascertain the pros and cons of any coating method.

In-vitro studies[18],[19],[31],[33],[40] evaluating the effect of np coatings on orthodontic brackets and bands have reported significant antibacterial activity and very less bacterial adhesion on these surface-modified orthodontic appliances when compared with uncoated controls.

A short-term in-vivo clinical study by Venkatesan et al.[41] observed that over a period of 1 month titanium dioxide (·) np-coated NiTi archwires exhibited lower levels of bacterial adhesion (S. mutans).

Nanoparticles offer a new direction into managing the bacterial accumulation secondary to orthodontic treatment, but evidence on the biosafety of such coatings is still inconclusive.


A major limitation in this review is the inclusion of only in-vitro studies, which provide a great insight into the realm of possibilities with biomaterials, but the results observed cannot accurately replicate the complex interactions occurring within the oral environment. As the number of studies included in the review was limited and due to the heterogeneity in their methodologies, a quantitative analysis could not be performed. Another limitation of this review was the inability to perform a direct comparison of the antibacterial activity of different coatings used for surface modification of orthodontic archwires. The language constraint limited the number of studies that could be included in the review.

  Conclusion Top

With the limited evidence available from the in-vitro studies that were included in the qualitative analysis, it can be concluded that the surface modification of orthodontic archwires by coating with np appears to offer some level of antibacterial and anti-adherence activity and this activity is significant when compared with that of uncoated control orthodontic archwires.

List of abbreviations

Ag-np - silver nanoparticles

CFU - colony forming unit

CuNiTi - copper nickel titanium

np - nanoparticles

NiTi - nickel titanium

SS - stainless steel

ZnO-np - zinc oxide nanoparticles


Not applicable.

Financial support and sponsorship

No sources of funding to report.

Conflicts of interest

The authors have no conflict of interest to report.

Authors’ contribution

Not applicable.

Ethical policy and Institutional Review Board statement

Not applicable.

Patient declaration of consent

Not applicable.

Data availability statement

Further data will be available on request. Kindly contact the corresponding author through email on [email protected].

  References Top

Balenseifen JW, Madonia JV Study of dental plaque in orthodontic patients. J Dent Res 1970;49:320-4.  Back to cited text no. 1
Sudjalim TR, Woods MG, Manton DJ Prevention of white spot lesions in orthodontic practice: A contemporary review. Aust Dent J 2006;51:284-9; quiz 347.  Back to cited text no. 2
Julien KC, Buschang PH, Campbell PM Prevalence of white spot lesion formation during orthodontic treatment. Angle Orthod 2013;83:641-7.  Back to cited text no. 3
Tufekci E, Dixon JS, Gunsolley JC, Lindauer SJ Prevalence of white spot lesions during orthodontic treatment with fixed appliances. Angle Orthod 2011;81:206-10.  Back to cited text no. 4
Indiran MA, Subramanian AK, Prabakar J, Pradeep Kumar R, Sri Sakthi D, Leelavathi L Concerns with oral health care services for adults with cognitive and intellectual disabilities. Bioinformation 2020;16:974-82.  Back to cited text no. 5
Gorelick L, Geiger AM, Gwinnett AJ Incidence of white spot formation after bonding and banding. Am J Orthod 1982;81:93-8.  Back to cited text no. 6
Artun J, Brobakken BO Prevalence of carious white spots after orthodontic treatment with multibonded appliances. Eur J Orthod 1986;8:229-34.  Back to cited text no. 7
Artun J, Thylstrup A Clinical and scanning electron microscopic study of surface changes of incipient caries lesions after debonding. Scand J Dent Res 1986;94:193-201.  Back to cited text no. 8
Ogaard B, Rølla G, Arends J Orthodontic appliances and enamel demineralization. Part 1. Lesion development. Am J Orthod Dentofacial Orthop 1988;94:68-73.  Back to cited text no. 9
Varghese RM, Subramanian AK, Sreenivasagan S. Comparison of dentoskeletal changes in skeletal class II cases using two different fixed functional appliances: Forsus Fatigue Resistant Device and PowerScope Class II corrector—A clinical study. J Int Oral Health 2021;13:234.  Back to cited text no. 10
Eliades T, Eliades G, Brantley WA Microbial attachment on orthodontic appliances: I. Wettability and early pellicle formation on bracket materials. Am J Orthod Dentofacial Orthop 1995;108:351-60.  Back to cited text no. 11
Menzaghi N, Saletta M, Garattini G, Brambilla E, Strohmenger L [Changes in the yeast oral flora in patients in orthodontic treatment]. Prev Assist Dent 1991;17:26-30.  Back to cited text no. 12
Chatterjee R, Kleinberg I Effect of orthodontic band placement on the chemical composition of human incisor tooth plaque. Arch Oral Biol 1979;24:97-100.  Back to cited text no. 13
Rosenbloom RG, Tinanoff N Salivary Streptococcus mutans levels in patients before, during, and after orthodontic treatment. Am J Orthod Dentofacial Orthop 1991;100:35-7.  Back to cited text no. 14
Sirelkhatim A, Mahmud S, Seeni A, Kaus NHM, Ann LC, Bakhori SKM, et al. Review on zinc oxide nanoparticles: Antibacterial activity and toxicity mechanism. Nanomicro Lett 2015;7:219-42.  Back to cited text no. 15
Dizaj SM, Lotfipour F, Barzegar-Jalali M, Zarrintan MH, Adibkia K Antimicrobial activity of the metals and metal oxide nanoparticles. Mater Sci Eng C Mater Biol Appl 2014;44:278-84.  Back to cited text no. 16
Król A, Pomastowski P, Rafińska K, Railean-Plugaru V, Buszewski B Zinc oxide nanoparticles: Synthesis, antiseptic activity and toxicity mechanism. Adv Colloid Interface Sci 2017;249:37-52.  Back to cited text no. 17
Shah AG, Shetty PC, Ramachandra CS, Bhat NS, Laxmikanth SM In vitro assessment of photocatalytic titanium oxide surface modified stainless steel orthodontic brackets for antiadherent and antibacterial properties against Lactobacillus acidophilus. Angle Orthod 2011;81:1028-5.  Back to cited text no. 18
Chun MJ, Shim E, Kho EH, Park KJ, Jung J, Kim JM, et al. Surface modification of orthodontic wires with photocatalytic titanium oxide for its antiadherent and antibacterial properties. Angle Orthod 2007;77:483-8.  Back to cited text no. 19
Zhang L-C, Chen L-Y, Wang L Surface modification of titanium and titanium alloys: Technologies, developments, and future interests. Adv Eng Mater 2020;22:1901258.  Back to cited text no. 20
Bącela J, Łabowska MB, Detyna J, Zięty A, Michalak I Functional coatings for orthodontic archwires—A review. Materials [Internet] 2020;13:1-26. Available from:  Back to cited text no. 21
Kim IH, Park HS, Kim YK, Kim KH Comparative short-term in vitro analysis of mutans streptococci adhesion on esthetic, nickel-titanium, and stainless-steel arch wires. Angle Orthod [Internet]. 2014:680-6; Available from:  Back to cited text no. 22
Vert M, Doi Y, Hellwich K-H, Hess M, Hodge P, Kubisa P, et al. Terminology for biorelated polymers and applications (IUPAC Recommendations 2012) [Internet]. Pure Appl Chem 2012;84:377-410. Available from:  Back to cited text no. 23
Kiss LB, Söderlund J, Niklasson GA, Granqvist CG New approach to the origin of lognormal size distributions of nanoparticles. Nanotechnology 1999;10:25-8.  Back to cited text no. 24
Borzabadi-Farahani A, Borzabadi E, Lynch E Nanoparticles in orthodontics, a review of antimicrobial and anti-caries applications. Acta Odontol Scand 2014;72:413-7.  Back to cited text no. 25
Cao B, Wang Y, Li N, Liu B, Zhang Y Preparation of an orthodontic bracket coated with an nitrogen-doped tio(2-x)N(y) thin film and examination of its antimicrobial performance. Dent Mater J 2013;32:311-6.  Back to cited text no. 26
Salehi P, Babanouri N, Roein-Peikar M, Zare F Long-term antimicrobial assessment of orthodontic brackets coated with nitrogen-doped titanium dioxide against Streptococcus mutans. Prog Orthod 2018;19:35.  Back to cited text no. 27
Karandish M, Pakshir M, Moghimi M, Jafarpour D Evaluating the mechanical properties of zinc-coated stainless steel orthodontic wires using physical vapor deposition. Int J Dent 2021;2021:6651289.  Back to cited text no. 28
Gracco A, Dandrea M, Deflorian F, Zanella C, De Stefani A, Bruno G, et al. Application of a molybdenum and tungsten disulfide coating to improve tribological properties of orthodontic archwires. Nanomaterials (Basel) [Internet]. 2019;9:1-10. Available from:  Back to cited text no. 29
Ehsani S, Mandich MA, El-Bialy TH, Flores-Mir C Frictional resistance in self-ligating orthodontic brackets and conventionally ligated brackets. A systematic review. Angle Orthod 2009;79:592-601.  Back to cited text no. 30
Jasso-Ruiz I, Velazquez-Enriquez U, Scougall-Vilchis RJ, Morales-Luckie RA, Sawada T, Yamaguchi R Silver nanoparticles in orthodontics, a new alternative in bacterial inhibition: In vitro study. Prog Orthod 2020;21:24.  Back to cited text no. 31
Gil FJ, Espinar-Escalona E, Clusellas N, Fernandez-Bozal J, Artes-Ribas M, Puigdollers A New bactericide orthodonthic archwire: NiTi with silver nanoparticles. Metals 2020;10:702.  Back to cited text no. 32
Yun K, Oh G, Vang M, Yang H, Lim H, Koh J, et al. Antibacterial effect of visible light reactive TiO2/Ag nanocomposite thin film on the orthodontic appliances. J Nanosci Nanotechnol 2011;11:7112-4.  Back to cited text no. 33
Morán-Martínez J, Beltrán del Río-Parra R Evaluation of the coating with TiO2 nanoparticles as an option for the improvement of the characteristics of NiTi archwires: Histopathological, cytotoxic, and genotoxic evidence. J Nanomater [Internet]. 2018:1-11; Available from:  Back to cited text no. 34
Hammad SM, El-Wassefy NA, Shamaa MS, Fathy A Evaluation of zinc-oxide nanocoating on the characteristics and antibacterial behavior of nickel-titanium alloy. Dental Press J Orthod 2020;25:51-8.  Back to cited text no. 35
Mhaske AR, Shetty PC, Bhat NS, Ramachandra CS, Laxmikanth SM, Nagarahalli K, et al. Antiadherent and antibacterial properties of stainless steel and NiTi orthodontic wires coated with silver against Lactobacillus acidophilus—An in vitro study. Prog Orthod 2015;16:40.  Back to cited text no. 36
Kachoei M, Nourian A, Divband B, Kachoei Z, Shirazi S Zinc-oxide nanocoating for improvement of the antibacterial and frictional behavior of nickel-titanium alloy. Nanomedicine (Lond) 2016;11:2511-27.  Back to cited text no. 37
Espinosa-Cristóbal LF, López-Ruiz N, Cabada-Tarín D, Reyes-López SY, Zaragoza-Contreras A, Constandse-Cortéz D, et al. Antiadherence and antimicrobial properties of silver nanoparticles against Streptococcus mutans on brackets and wires used for orthodontic treatments [Internet]. J Nanomater 2018;2018:1-11. Available from:  Back to cited text no. 38
Gonçalves IS, Viale AB, Sormani NN, Pizzol KEDC, de Araujo-Nobre AR, de Oliveira PCS, et al. Antimicrobial orthodontic wires coated with silver nanoparticles. Braz Arch Biol Technol [Internet] 2020;63:1-10. Available from:​46VYkSZgh6NDMV5NkGG7GMd/abstract/?lang=en.  Back to cited text no. 39
Ramazanzadeh B, Jahanbin A, Yaghoubi M, Shahtahmassbi N, Ghazvini K, Shakeri M, et al. Comparison of antibacterial effects of ZnO and CuO nanoparticles coated brackets against Streptococcus mutans. J Dent (Shiraz) 2015;16:200-5.  Back to cited text no. 40
Venkatesan K, Kailasam V, Padmanabhan S Evaluation of titanium dioxide coating on surface roughness of nickel-titanium archwires and its influence on Streptococcus mutans adhesion and enamel mineralization: A prospective clinical study. Am J Orthod Dentofacial Orthop 2020;158:199-208.  Back to cited text no. 41


  [Figure 1], [Figure 2]

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5]


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