Evidence map›Paper›PMID 40956446›Full record

ArticleLasers in medical science2025

Effects of antimicrobial photodynamic therapy with zinc oxide and toluidine blue on Streptococcus mutans accumulation in polymethyl methacrylate resin used in orthodontic appliances.

Erfan Mortazavi Zadeh, Amirhossein Mirhashemi, Maryam Pourhajibagher, Mahsa Ghorbani, Hooman Shafaee, Behrad Tanbakuchi

Abstract read
PubMed Publisher
In one paragraph

Article in Lasers in medical science, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors.

Erfan Mortazavi ZadehDentist, Private practice, Tehran, Iran.
Amirhossein MirhashemiDepartment of Orthodontics, School ofDentistry, Tehran University of Medical Sciences, Tehran, Iran. mirhashemi@tums.ac.ir.
Maryam PourhajibagherDental Research Center, Dentistry Research Institute, Tehran Universityof Medical Sciences, Tehran, Iran.
Mahsa GhorbaniDental Research Center, Department of Orthodontics, Mashhad University of Medical Sciences, Mashhad, Iran.
Hooman ShafaeeDental Research Center, Department of Orthodontics, Mashhad University of Medical Sciences, Mashhad, Iran.
Behrad TanbakuchiDepartment of Orthodontics, School ofDentistry, Tehran University of Medical Sciences, Tehran, Iran. behrad.tanbakuchi@yahoo.com.

Funding

Tehran University of Medical Sciences and Health Services 73376
6 · The paper itself

Abstract

objectiveThe aim of this study was to evaluate the efficacy of antimicrobial photodynamic therapy (aPDT) using toluidine blue (TBO) activated by a diode laser and zinc oxide (ZnO) activated by light-emitting diode (LED) light in reducing bacterial accumulation on polymethyl methacrylate (PMMA) orthodontic appliances.

methodsThis in-vitro study investigated the formation of Streptococcus mutans biofilm on 32 PMMA resin discs, divided into four groups. The first group consisted of acrylic discs containing ZnO exposed to 450 nm LED radiation; the second group included acrylic discs with TBO and 635 nm diode laser radiation; the third group was the positive control with chlorhexidine (CHX); and the fourth group served as the negative control. To evaluate biofilm formation, the discs were immersed in tubes containing a microbial suspension at a 0.5 McFarland concentration. Following incubation, the discs were exposed to light according to the type of photosensitizer. After washing with saline and sonication, bacterial colony counts were determined by serial dilution and culture in Brian Heart Infusion agar medium. One-way ANOVA was used to compare the colony-forming unit (CFU) counts, and post-hoc Tamhane's test was performed for pairwise comparisons, with statistical significance set at p < 0.05.

resultsThe negative control group exhibited the highest mean colony count (35.72 ± 3.35 CFU/mL), while the positive control group showed the lowest mean colony count (5.87 ± 0.92 CFU/mL). Both ZnO and TBO groups, when activated by their respective light sources, demonstrated significant antibacterial activity compared to the negative control (P < 0.001 for both). However, CHX outperformed both ZnO and TBO in reducing bacterial growth (P < 0.001 and P = 0.007, respectively). No statistically significant difference was observed between the antibacterial effects of ZnO and TBO (P = 0.280).

conclusionThis study suggests that aPDT using ZnO and TBO can be an effective adjunctive treatment for reducing bacterial accumulation on orthodontic appliances. While CHX remains the most effective treatment, the cost-effectiveness and ease of application of both CHX and ZnO make them viable options for future clinical trials. Further research is needed to optimize treatment protocols and explore the potential impact of these treatments on other microorganisms and material properties.

Indexed as

Orthodontic AppliancesPhotochemotherapyPhotosensitizing AgentsPolymethyl MethacrylateStreptococcus mutansTolonium ChlorideZinc OxideBiofilmsChlorhexidineHumansIn Vitro TechniquesLasers, SemiconductorChlorhexidinePhotosensitizing AgentsPolymethyl MethacrylateTolonium ChlorideZinc OxideDentistryOrthodontic appliancesOrthodonticsPhotodynamic therapyPolymethyl methacrylate

Identifiers

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.