Comparative Efficacy of Photodynamic Therapy and Conventional Methods for the Disinfection of Clear Thermoplastic Sheets: An In Vitro Study
-
Leila Pourmousa
,
Amirhossein Mirhashemi
,
Mohammad Ali Keshvad
,
Sogol Saberi
,
Yasaman Sanaee
,
Maryam Pourhajibagher
Abstract
Objectives: This study compared the efficacy of photodynamic therapy (PDT) with that of conventional methods for disinfection of clear thermoplastic sheets used for the fabrication of aligners.
Materials and Methods: In this study, 70 pieces of clear dental aligners measuring 15×15mm were gamma-sterilized, and randomly assigned to two groups (n=35) for inoculation with Streptococcus mutans and Lactobacillus acidophilus. After biofilm formation, the specimens were randomly assigned to 7 subgroups for disinfection with 0.2% chlorhexidine (CHX), 2.5% acetic acid, 3% hydrogen peroxide (HP), 100 µL/mL methylene blue (MB), PDT with MB and diode laser, diode laser alone, and distilled water (control). After sonication and culture, the colonies were counted and compared using ANOVA, Tamhane, and one sample t-test (alpha=0.05).
Results: HP showed the highest efficacy in both bacterial groups (P<0.05). In S. mutans group, CHX had a significantly higher efficacy than the other modalities (P<0.05). Distilled water showed no significant difference compared with MB or laser (P>0.05), and acetic acid showed no significant difference compared with PDT (P>0.05). In the L. acidophilus group, CHX demonstrated significantly higher efficacy than the other modalities (P<0.05). Distilled water showed no significant difference compared with laser, and acetic acid showed no significant difference compared with PDT (P>0.05).
Conclusion: Within the limitations of this in vitro study, PDT demonstrated moderate antibacterial activity against S. mutans and L. acidophilus biofilms. However, HP followed by CHX showed significantly greater antibacterial efficacy and remained the most effective disinfection approach among those evaluated.
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12. Axe AS, Varghese R, Bosma M, Kitson N, Bradshaw DJ. Dental health professional recommendation and consumer habits in denture cleansing. J Prosthet Dent. 2016 Feb;115(2):183-8.
13. Freitas LB, Vassilakos N, Arnebrant T. Interactions of chlorhexidine with salivary films adsorbed at solid/liquid and air/liquid interfaces. J Periodontal Res. 1993 Mar;28(2):92-7.
14. Wible E, Agarwal M, Altun S, Ramir T, Viana G, Evans C, et al. Long-term effects of various cleaning methods on polypropylene/ethylene copolymer retainer material. Angle Orthod. 2019 May;89(3):432-437.
15. McGowan MJ, Shimoda LM, Woolsey GD. Effects of sodium hypochlorite on denture base metals during immersion for short-term sterilization. J Prosthet Dent. 1988 Aug;60(2):212-8.
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18. Inchingolo AD, Malcangi G, Semjonova A, Inchingolo AM, Patano A, Coloccia G, et al. Oralbiotica/Oralbiotics: The Impact of Oral Microbiota on Dental Health and Demineralization: A Systematic Review of the Literature. Children (Basel). 2022 Jul 8;9(7):1014.
19. Ghorbani J, Rahban D, Aghamiri S, Teymouri A, Bahador A. Photosensitizers in antibacterial photodynamic therapy: an overview. Laser Ther. 2018 Dec 31;27(4):293-302.
20. Ricci Donato HA, Pratavieira S, Grecco C, Brugnera-Júnior A, Bagnato VS, Kurachi C. Clinical Comparison of Two Photosensitizers for Oral Cavity Decontamination. Photomed Laser Surg. 2017 Feb;35(2):105-110.
21. Al-Shammery D, Michelogiannakis D, Ahmed ZU, Ahmed HB, Rossouw PE, Romanos GE, Javed F. Scope of antimicrobial photodynamic therapy in Orthodontics and related research: A review. Photodiagnosis Photodyn Ther. 2019 Mar;25:456-459.
22. Sayar F, Karimi MR, Boroujerdi S. Efficacy of antimicrobial photodynamic therapy with chitosan nanoparticles for decontamination of dental implants contaminated with Aggregatibacter actinomycetemcomitans. Sci Rep. 2025 Oct 1;15(1):34213.
23. Silva Teófilo MÍ, de Carvalho Russi TMAZ, de Barros Silva PG, Balhaddad AA, Melo MAS, Rolim JPML. The Impact of Photosensitizer Selection on Bactericidal Efficacy Of PDT against Cariogenic Biofilms: A Systematic Review and Meta-Analysis. Photodiagnosis Photodyn Ther. 2021 Mar;33:102046.
24. Kiatwarawut K, Rokaya D, Sirisoontorn I. Antimicrobial Activity of Various Disinfectants to Clean Thermoplastic Polymeric Appliances in Orthodontics. Polymers (Basel). 2022 May 31;14(11):2256.
25. Akgün FA, Şenışık NE, Çetin ES. Evaluation of the Efficacy of Different Cleaning Methods for Orthodontic Thermoplastic Retainers in terms of Bacterial Colonization. Turk J Orthod. 2019 Dec 1;32(4):219-228.
26. Hakami Z, Alshehri AH. Antimicrobial efficacy, optical properties and flexural strength following antimicrobial photodynamic therapy over vacuum-formed orthodontic retainers. Photodiagnosis Photodyn Ther. 2022 Sep;39:102951.
27. Paramita C, Purwanegara MK, Hoesin F. Comparison of the efficacy of two disinfectants for controlling gram-positive bacteria on thermoplastic retainers in dental plaques. International Journal of Applied Pharmaceutics. 2019 Apr;11:126-9.
28. Shpack N, Greenstein RB, Vardimon A. RE: response to: Efficacy of three hygienic protocols in reducing biofilm adherence to removable thermoplastic appliance. The Angle Orthodontist 2014(1) 161-170. Angle Orthod. 2014 May;84(3):574.
29. Azizi A, Shohrati P, Goudarzi M, Lawaf S, Rahimi A. Comparison of the effect of photodynamic therapy with curcumin and methylene Blue on streptococcus mutans bacterial colonies. Photodiagnosis Photodyn Ther. 2019 Sep;27:203-209.
30. Méndez DAC, Gutierrez E, Dionísio EJ, Oliveira TM, Buzalaf MAR, Rios D, Machado MAAM, Cruvinel T. Effect of methylene blue-mediated antimicrobial photodynamic therapy on dentin caries microcosms. Lasers Med Sci. 2018 Apr;33(3):479-487.
31. Sobouti F, Dadgar S, Salehi A, Rezaei Kalantari N, Aryana M, Goli HR, et al. In Vitro Comparative Evaluation of the Efficacy of Antimicrobial Photodynamic Therapy, Chlorhexidine, Sodium Fluoride, and Hydrogen Peroxide for Acrylic Resin Disinfection. J Lasers Med Sci. 2023 Nov 4;14:e52.
2. Hirani S, Patel U, Patel N. Invisible orthodontics-a review. IOSR J Dent Med Sci. 2016 Jun;15(6):56-62.
3. Ren Y, Jongsma MA, Mei L, van der Mei HC, Busscher HJ. Orthodontic treatment with fixed appliances and biofilm formation--a potential public health threat? Clin Oral Investig. 2014 Sep;18(7):1711-8.
4. Moshiri M, Eckhart JE, McShane P, German DS. Consequences of poor oral hygiene during aligner therapy. J Clin Orthod. 2013 Aug;47(8):494-8.
5. Lagravère MO, Flores-Mir C. The treatment effects of Invisalign orthodontic aligners: a systematic review. J Am Dent Assoc. 2005 Dec;136(12):1724-9.
6. Wible E, Agarwal M, Altun S, Ramir T, Viana G, Evans C,et al Long-term effects of different cleaning methods on copolyester retainer properties. Angle Orthod. 2019 Mar;89(2):221-227.
7. Chang CS, Al-Awadi S, Ready D, Noar J. An assessment of the effectiveness of mechanical and chemical cleaning of Essix orthodontic retainer. J Orthod. 2014 Jun;41(2):110-7.
8. Albanna RH, Farawanah HM, Aldrees AM. Microbial evaluation of the effectiveness of different methods for cleansing clear orthodontic retainers: A randomized clinical trial. Angle Orthod. 2017 May;87(3):460-465.
9. Apratim A, Shah SS, Sinha M, Agrawal M, Chhaparia N, Abubakkar A. Denture hygiene habits among elderly patients wearing complete dentures. J Contemp Dent Pract. 2013 Nov 1;14(6):1161-4.
10. Baran I, Nalçacı R. Self-reported denture hygiene habits and oral tissue conditions of complete denture wearers. Arch Gerontol Geriatr. 2009 Sep-Oct;49(2):237-241.
11. Barreiro DM, Scheid PA, May LG, Unfer B, Braun KO. Evaluation of procedures employed for the maintenance of removable dentures in elderly individuals. Oral Health Prev Dent. 2009;7(3):243-9.
12. Axe AS, Varghese R, Bosma M, Kitson N, Bradshaw DJ. Dental health professional recommendation and consumer habits in denture cleansing. J Prosthet Dent. 2016 Feb;115(2):183-8.
13. Freitas LB, Vassilakos N, Arnebrant T. Interactions of chlorhexidine with salivary films adsorbed at solid/liquid and air/liquid interfaces. J Periodontal Res. 1993 Mar;28(2):92-7.
14. Wible E, Agarwal M, Altun S, Ramir T, Viana G, Evans C, et al. Long-term effects of various cleaning methods on polypropylene/ethylene copolymer retainer material. Angle Orthod. 2019 May;89(3):432-437.
15. McGowan MJ, Shimoda LM, Woolsey GD. Effects of sodium hypochlorite on denture base metals during immersion for short-term sterilization. J Prosthet Dent. 1988 Aug;60(2):212-8.
16. de Souza RF, de Freitas Oliveira Paranhos H, Lovato da Silva CH, Abu-Naba'a L, Fedorowicz Z, Gurgan CA. Interventions for cleaning dentures in adults. Cochrane Database Syst Rev. 2009 Oct 7;2009(4):CD007395.
17. Charavet C, Gourdain Z, Graveline L, Lupi L. Cleaning and Disinfection Protocols for Clear Orthodontic Aligners: A Systematic Review. Healthcare (Basel). 2022 Feb 10;10(2):340.
18. Inchingolo AD, Malcangi G, Semjonova A, Inchingolo AM, Patano A, Coloccia G, et al. Oralbiotica/Oralbiotics: The Impact of Oral Microbiota on Dental Health and Demineralization: A Systematic Review of the Literature. Children (Basel). 2022 Jul 8;9(7):1014.
19. Ghorbani J, Rahban D, Aghamiri S, Teymouri A, Bahador A. Photosensitizers in antibacterial photodynamic therapy: an overview. Laser Ther. 2018 Dec 31;27(4):293-302.
20. Ricci Donato HA, Pratavieira S, Grecco C, Brugnera-Júnior A, Bagnato VS, Kurachi C. Clinical Comparison of Two Photosensitizers for Oral Cavity Decontamination. Photomed Laser Surg. 2017 Feb;35(2):105-110.
21. Al-Shammery D, Michelogiannakis D, Ahmed ZU, Ahmed HB, Rossouw PE, Romanos GE, Javed F. Scope of antimicrobial photodynamic therapy in Orthodontics and related research: A review. Photodiagnosis Photodyn Ther. 2019 Mar;25:456-459.
22. Sayar F, Karimi MR, Boroujerdi S. Efficacy of antimicrobial photodynamic therapy with chitosan nanoparticles for decontamination of dental implants contaminated with Aggregatibacter actinomycetemcomitans. Sci Rep. 2025 Oct 1;15(1):34213.
23. Silva Teófilo MÍ, de Carvalho Russi TMAZ, de Barros Silva PG, Balhaddad AA, Melo MAS, Rolim JPML. The Impact of Photosensitizer Selection on Bactericidal Efficacy Of PDT against Cariogenic Biofilms: A Systematic Review and Meta-Analysis. Photodiagnosis Photodyn Ther. 2021 Mar;33:102046.
24. Kiatwarawut K, Rokaya D, Sirisoontorn I. Antimicrobial Activity of Various Disinfectants to Clean Thermoplastic Polymeric Appliances in Orthodontics. Polymers (Basel). 2022 May 31;14(11):2256.
25. Akgün FA, Şenışık NE, Çetin ES. Evaluation of the Efficacy of Different Cleaning Methods for Orthodontic Thermoplastic Retainers in terms of Bacterial Colonization. Turk J Orthod. 2019 Dec 1;32(4):219-228.
26. Hakami Z, Alshehri AH. Antimicrobial efficacy, optical properties and flexural strength following antimicrobial photodynamic therapy over vacuum-formed orthodontic retainers. Photodiagnosis Photodyn Ther. 2022 Sep;39:102951.
27. Paramita C, Purwanegara MK, Hoesin F. Comparison of the efficacy of two disinfectants for controlling gram-positive bacteria on thermoplastic retainers in dental plaques. International Journal of Applied Pharmaceutics. 2019 Apr;11:126-9.
28. Shpack N, Greenstein RB, Vardimon A. RE: response to: Efficacy of three hygienic protocols in reducing biofilm adherence to removable thermoplastic appliance. The Angle Orthodontist 2014(1) 161-170. Angle Orthod. 2014 May;84(3):574.
29. Azizi A, Shohrati P, Goudarzi M, Lawaf S, Rahimi A. Comparison of the effect of photodynamic therapy with curcumin and methylene Blue on streptococcus mutans bacterial colonies. Photodiagnosis Photodyn Ther. 2019 Sep;27:203-209.
30. Méndez DAC, Gutierrez E, Dionísio EJ, Oliveira TM, Buzalaf MAR, Rios D, Machado MAAM, Cruvinel T. Effect of methylene blue-mediated antimicrobial photodynamic therapy on dentin caries microcosms. Lasers Med Sci. 2018 Apr;33(3):479-487.
31. Sobouti F, Dadgar S, Salehi A, Rezaei Kalantari N, Aryana M, Goli HR, et al. In Vitro Comparative Evaluation of the Efficacy of Antimicrobial Photodynamic Therapy, Chlorhexidine, Sodium Fluoride, and Hydrogen Peroxide for Acrylic Resin Disinfection. J Lasers Med Sci. 2023 Nov 4;14:e52.
| Issue | Vol 23 (Continuously Published Article-Based) | |
| Section | Original Article | |
| Keywords | ||
| Lactobacillus acidophilus Lasers Methylene Blue Orthodontic Appliances Photochemotherapy Streptococcus mutans | ||
| Rights and permissions | |
|
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. |
How to Cite
1.
Pourmousa L, Mirhashemi A, Keshvad MA, Saberi S, Sanaee Y, Pourhajibagher M. Comparative Efficacy of Photodynamic Therapy and Conventional Methods for the Disinfection of Clear Thermoplastic Sheets: An In Vitro Study. Front Dent. 2026;23.
