Effects of silver diamine fluoride combined with potassium iodide and diode laser irradiation on antibacterial activity and microleakage: an in vitro study

Background: Silver diamine fluoride (SDF) is widely used in minimally invasive caries management; however, limited evidence exists regarding the combined use of potassium iodide (KI) and diode laser irradiation, particularly concerning their effects on antibacterial efficacy and microleakage of glass hybrid restorations. Methods: This in vitro study included 144 sound permanent molars. For antibacterial evaluation, a dual-species biofilm of Streptococcus mutans and Lacticaseibacillus casei was established on 72 dentin disks (2 mm thick), randomly assigned to six groups (n = 12): SDF + KI, SDF only, SDF + KI + diode laser, SDF + diode laser, diode laser only, and control. Antibacterial activity was assessed using confocal laser scanning microscopy and scanning electron microscopy. For microleakage evaluation, 72 standardized Class V cavities were prepared and assigned to the same six experimental groups using identical treatment protocols. All cavities were restored with a glass-hybrid restorative material and subjected to thermocycling. Dye penetration was evaluated using basic fuchsin under stereomicroscopy. Antibacterial outcomes were analyzed using generalized estimating equations with pairwise comparisons, while microleakage outcomes were analyzed using the Kruskal-Wallis test. Results: A statistically significant difference in antibacterial activity was observed between the control group and all experimental groups (p < 0.05). The SDF + KI + diode laser group demonstrated significantly greater antibacterial activity than the SDF group and diode laser only group (p < 0.05). No statistically significant differences were detected among the groups with respect to microleakage; however, KI-containing groups showed higher median microleakage values, whereas the lowest median value was observed in the control group (p > 0.05). Conclusions: Within the limitations of this in vitro study, the combination of SDF, KI, and diode laser irradiation demonstrated the most pronounced antibacterial effect among the tested protocols, without significantly affecting microleakage performance of glass-hybrid restorations under the present experimental conditions.

Silver diamine fluoride; Diode laser; Potassium iodide; Microleakage; Glass hybrid; Antibacterial efficacy

[1] Horst JA, Ellenikiotis H, Milgrom PM. UCSF protocol for caries arrest using silver diamine fluoride: rationale, indications, and consent. Journal of the California Dental Association. 2016; 44: 16–28.

[2] Al-Kaff AA, Alshehri AZ, Alasmari RA, Alsubaie N, Aldaws A, Althaqeel A, et al. Minimally invasive techniques for managing dental caries in children: efficacy, applications, and future directions. Cureus. 2025; 17: e87450.

[3] Varughese A, Janakiram C, Karuveettil V, James A. Effectiveness of silver diamine fluoride application with atraumatic restorative treatment in arresting the progression of dental caries: a systematic review protocol. JBI Evidence Synthesis. 2024; 22: 1617–1625.

[4] American Academy of Pediatric Dentistry. Policy on the use of silver diamine fluoride for pediatric dental patients. The Reference Manual of Pediatric Dentistry (pp. 103–105). American Academy of Pediatric Dentistry: Chicago. 2023.

[5] Soliman N, Bakry NS, Mohy ElDin MH, Talaat DM. Effect of silver diamine fluoride pretreatment on microleakage and shear bond strength of resin-modified glass ionomer cement to primary dentin: an in vitro study. Alexandria Dental Journal. 2021; 46: 151–156.

[6] Sayed M, Matsui N, Hiraishi N, Inoue G, Nikaido T, Burrow MF, et al. Evaluation of discoloration of sound/demineralized root dentin with silver diamine fluoride: in vitro study. Dental Materials Journal. 2019; 38: 143–149.

[7] Patel J, Anthonappa RP, King NM. Evaluation of the staining potential of silver diamine fluoride: in vitro. International Journal of Paediatric Dentistry. 2018; 28: 514–522.

[8] Knight GM, McIntyre JM. The effect of silver fluoride and potassium iodide on the bond strength of auto-cure glass ionomer cement to dentine. Australian Dental Journal. 2006; 51: 42–45.

[9] Lepri CP, De Castro DT, Geraldo-Martins VR, Faraoni JJ, Palma-Dibb RG. Laser irradiation prevents root caries: microhardness and scanning electron microscopy analysis. Indian Journal of Dental Research. 2022; 33: 198–202.

[10] Mei ML, Ito L, Chu CH, Lo EC, Zhang CF. Prevention of dentine caries using silver diamine fluoride application followed by Er:YAG laser irradiation: an in vitro study. Lasers in Medical Science. 2014; 29: 1785–1791.

[11] Vitale MC, Zaffe D, Botticell AR, Caprioglio C. Diode laser irradiation and fluoride uptake in human teeth. European Archives of Paediatric Dentistry. 2011; 12: 90–92.

[12] Blanken J, De Moor RJ, Meire M, Verdaasdonk R. Laser induced explosive vapor and cavitation resulting in effective irrigation of the root canal. Part 1: a visualization study. Lasers in Surgery and Medicine. 2009; 41: 514–519.

[13] Luk K, Zhao IS, Yu OY, Mei ML, Gutknecht N, Chu CH. Caries prevention effects of silver diamine fluoride with 10,600-nm carbon dioxide laser irradiation on dentin. Photobiomodulation, Photomedicine, and Laser Surgery. 2020; 38: 295–300.

[14] Hassan M, Bakhurji E, AlSheikh R. Application of Er,Cr:YSGG laser versus photopolymerization after silver diamine fluoride in primary teeth. Scientific Reports. 2021; 11: 20780.

[15] Singh K, Jhingan P, Malik M, Mathur S. In vitro comparative evaluation of physical and chemical properties of surface enamel after using APF and SDF with or without laser activation. European Archives of Paediatric Dentistry. 2023; 24: 461–472.

[16] Al-Hamdan RS. Caries-affected dentin disinfection using ozone, methylthioninium chloride and turmeric activated by photodynamic therapy on bond integrity of resin-modified glass ionomer cement. Photodiagnosis and Photodynamic Therapy. 2021; 36: 102613.

[17] Cirdei MV, Margan MM, Margan R, Ban-Cucerzan A, Petre I, Hulka I, et al. Surface and mineral changes of primary enamel after laser diode irradiation and application of remineralization agents: a comparative in vitro study. Children. 2024; 11: 1069.

[18] Çelik EU, Tunac AT, Yilmaz F. A randomized, controlled, split-mouth trial evaluating the clinical performance of high-viscosity glass-ionomer restorations in noncarious cervical lesions: two-year results. The Journal of Adhesive Dentistry. 2018; 20: 299–305.

[19] Silveira de Araujo C, Incerti da Silva T, Ogliari FA, Meireles SS, Piva E, Demarco FF. Microleakage of seven adhesive systems in enamel and dentin. The Journal of Contemporary Dental Practice. 2006; 7: 26–33.

[20] Chai HH, Kiuchi S, Osaka K, Aida J, Chu CH, Gao SS. Knowledge, practices and attitudes towards silver diamine fluoride therapy among dentists in Japan: a mixed methods study. International Journal of Environmental Research and Public Health. 2022; 19: 8705.

[21] Clemens J, Gold J, Chaffin J. Effect and acceptance of silver diamine fluoride treatment on dental caries in primary teeth. Journal of Public Health Dentistry. 2018; 78: 63–68.

[22] Cömert H, Olmez A. Effects of glutathione and potassium iodide on silver diamine fluoride application on remineralisation and colour change in dentine caries of primary teeth: an in vitro study. European Archives of Paediatric Dentistry. 2025; 26: 169–181.

[23] Gadallah LK, Safwat EM, Saleh RS, Azab SM, Azab MM. Effect of silver diamine fluoride/potassium iodide treatment on the prevention of dental erosion in primary teeth: an in vitro study. BDJ Open. 2023; 9: 24.

[24] Karaduran B, Çelik S, Üçüncü MY, Topçuoğlu N, Gök MK, Koruyucu M. Antibacterial effects of silver diamine fluoride, potassium iodide and nanosilver fluoride on dual-species biofilm. Journal of Dentistry. 2024; 147: 105097.

[25] Mei ML, Chu CH, Low KH, Che CM, Lo EC. Caries-arresting effect of silver diamine fluoride on dentine carious lesions with Streptococcus mutans and Lactobacillus acidophilus dual-species cariogenic biofilm. Medicina Oral, Patologia Oral, Cirugia Bucal. 2013; 18: e824–e831.

[26] Vinson LA, Gilbert PR, Sanders BJ, Moser E, Gregory RL. Silver diamine fluoride and potassium iodide disruption of in vitro Streptococcus mutans biofilm. Journal of Dentistry for Children. 2018; 85: 120–124.

[27] Umana M, Heysselaer D, Tielemans M, Compere P, Zeinoun T, Nammour S. Dentinal tubules sealing by means of diode lasers (810 and 980 nm): a preliminary in vitro study. Photomedicine and Laser Surgery. 2013; 31: 307–314.

[28] Nandkumar A, Iyer VH. In vitro analysis comparing efficacy of lasers and desensitizing agents on dentin tubule occlusion: a scanning electron microscope study. International Journal of Laser Dentistry. 2014; 4: 1–7.

[29] Amer NS, El-Yazeed MA, Zaky AA, El-Tayeb EA, Hassouna DM. In vitro controlled elemental analysis to evaluate the combined effect of acidulated phosphate fluoride with Er:YAG and diode lasers. Canadian Journal of Dental Hygiene. 2023; 57: 25–32.

[30] Gojkov-Vukelic M, Hadzic S, Zukanovic A, Pasic E, Pavlic V. Application of diode laser in the treatment of dentine hypersensitivity. Medical Archives. 2016; 70: 466–469.

[31] Moharam LM, Sadony DM, Nagi SM. Evaluation of diode laser application on chemical analysis and surface microhardness of white spot enamel lesions with two remineralizing agents. Journal of Clinical and Experimental Dentistry. 2020; 12: e271–e276.

[32] Villalba-Moreno J, González-Rodríguez A, López-González JD, Bolanos-Carmona MV, Pedraza-Muriel V. Increased fluoride uptake in human dental specimens treated with diode laser. Lasers in Medical Science. 2007; 22: 137–142.

[33] Guarato FRBA, Santi MR, Madalena IR, Geraldo Martins VR, Menezes-Oliveira MAH, Castro DT, et al. Er,Cr:YSGG and 980-nm diode lasers influence dentin surface volume after cariogenic challenge: an in vitro study. Brazilian Oral Research. 2024; 38: e045.

[34] Mareddy AR, Reddy VN, Rehaman T, Done V, Kovuru R, Challa S. Evaluating surface microhardness in silver diamine fluoride-treated primary dentin post-laser irradiation: an in vitro study of three laser modalities. International Journal of Clinical Pediatric Dentistry. 2025; 18: 1071–1076.

[35] Bhati V, Srivastava VK. Effect of laser irradiation on fluoride uptake in primary teeth treated with 38% silver diamine fluoride or 5% sodium fluoride varnish: an in vitro study. International Journal of Clinical Pediatric Dentistry. 2025; 18: 1418–1425.

[36] Goswami M, Johnson RM, Singh A. Pretreatment and posttreatment effect of laser on the color and surface characteristics of silver diamine fluoride-treated carious primary molars: an in vitro study. Journal of Indian Society of Pedodontics and Preventive Dentistry. 2025; 43: 582–588.

[37] Hamouda ME, Harp YS, Elembaby AE. Evaluation of microleakage and micromorphological analysis of different self-adhesive restorative systems in class V cavities: laboratory study. Journal of Clinical and Experimental Dentistry. 2025; 17: e805–e815.

[38] Basra AS, Sedani S, Phaye L, Khetan R. Addition of silver diamine fluoride to restorative materials: effect on microhardness and microleakage. Biomaterial Investigations in Dentistry. 2025; 12: 43074.

[39] Al Qassar SS, Alkhayat ZI, Al Mallah MR. Bond integrity and microleakage of orthodontic bands cemented by glass ionomer cements stored in static magnetic field. Journal of Advanced Oral Research. 2024; 15: 151–157.

[40] Khan M, Maran S, Khan R, Rawal A, Jain P, Khan A. Microleakage between conventional GIC, RMGIC and glass hybrid bulkfill restorative system to restore class I cavities in primary molars: an in vitro study. Bioinformation. 2025; 21: 1279–1285.

[41] Uzel I, Ulukent O, Cogulu D. The effect of silver diamine fluoride on microleakage of resin composite. Journal of International Dental and Medical Research. 2013; 6: 105–108.

[42] Powell JD, Acosta C, Wells MH, Morrow BR, Vinall CV, Garcia-Godoy F. Microleakage of silver-modified atraumatic restorative technique restorations using silver diamine fluoride and high-viscosity glass ionomer. Pediatric Dentistry. 2024; 46: 204–208.

[43] Meraji A, Asadian F, Hekmatfar S. Effect of silver diamine fluoride and potassium iodide on microleakage of composite resin in anterior primary teeth. The Journal of Contemporary Dental Practice. 2024; 25: 691–695.

[44] Mohammed NY, Abdel-Ghany DM, Ben Hamadi N, Özdemir S, Selamoglu Z, Plavan G, et al. The impact of silver diamine fluoride only or simultaneously with potassium iodide treatment on the bond durability of resin composite material on primary teeth. Cureus. 2024; 16: e57064.

[45] Lugassy D, Segal P, Blumer S, Eger M, Shely A, Matalon S. Effect of two traditional polyacrylic acid conditioners and 2% chlorhexidine digluconate on cavosurface microleakage of glass ionomer restorations. Journal of Clinical Pediatric Dentistry. 2018; 42: 287–291.