Providone Iodine Producing Great Results in Fighting Carries

Brief Literature Review: Povidone-Iodine (PVP-I)

Revised and updated January 2026
Peter Milgrom, DDS
Emeritus Professor of Oral Health Sciences, University of Washington

Background

Topical fluorides have been the mainstay in the prevention of dental caries for decades. There are abundant data on sodium fluoride (NaF) and its ability to foster remineralization of tooth enamel (Gao et al., 2016).

Dental NaF varnish preparations are the recommended vehicle for delivering topical NaF for dental caries prevention and arrest in young children under six years of age, according to guidelines from the American Dental Association (ADA), the American Academy of Pediatrics, the American Academy of Pediatric Dentistry, and the U.S. Preventive Services Task Force (Weyant et al., 2013; Clark et al., 2014; American Academy of Pediatric Dentistry, 2013; Moyer, 2014).

In children under six years of age who are at high risk for dental caries, the recommendation is application of NaF varnish every three months (Weyant et al., 2013). Fluoride varnishes have been shown to be safe in very young children (Milgrom et al., 2014).

Limitations of Fluoride Alone

However, topical fluorides alone are not sufficient to prevent tooth decay in high-risk populations. Caries researchers have long suggested strategies that combine topical antiseptic application to reduce or eliminate tooth-surface colonization by cariogenic bacteria, in addition to topical fluoride applications that primarily remineralize enamel (Milgrom et al., 2009).

Povidone-iodine is an FDA-approved and widely used bactericidal antiseptic. Within the oral flora, iodine has preferential activity against streptococcal species, which are pathogens implicated in the causation of dental caries (Tam et al., 2006; Furiga et al., 2008). Additionally, iodine’s effectiveness may persist for as long as six months (Caufield et al., 1979).

Evidence Supporting PVP-I Use

Several studies have examined the chemotherapeutic suppression of Streptococcus mutans (Sm) using 10% povidone-iodine in children with Severe Early Childhood Caries (S-ECC).

In one study, children aged two to six years received topical treatment with either 10% povidone-iodine or saline following dental treatment under general anesthesia for S-ECC (Zhan et al., 2006). Levels of Streptococcus mutans were significantly reduced for up to three months in the povidone-iodine group.

A second study demonstrated suppression of Streptococcus mutans for up to 90 days in children with S-ECC who received a single application of 10% povidone-iodine followed by 1.23% acidulated phosphate fluoride foam after surgical elimination of active caries lesions (Berkowitz et al., 2009).

Caries Prevention Studies

Other studies have assessed the direct impact of 10% povidone-iodine on dental caries prevention.

A clinical study involving infants in Puerto Rico who were at high risk for S-ECC—due to colonization by Streptococcus mutans and decay-promoting feeding behaviors—demonstrated that bimonthly application of 10% povidone-iodine successfully prevented the development of early tooth-decay lesions in maxillary primary incisors (Lopez et al., 2002).

In a randomized clinical trial, bi-monthly application of 10% povidone-iodine significantly reduced the rate of recurrent dental decay six months after treatment under general anesthesia for S-ECC (Amin et al., 2004).

Sequential PVP-I and Fluoride Varnish

Two cohort studies evaluated the effect of combining these two anti-caries agents by sequentially applying 10% povidone-iodine followed by 5% sodium fluoride varnish.

The first study assessed protection of erupting first permanent molars in children aged five to six years (Tut & Milgrom, 2010). The second evaluated primary dentition outcomes in children aged 12 to 30 months (Milgrom, Tut & Mancl, 2011).

Both studies demonstrated that treatment with povidone-iodine significantly reduced the rate of new decay compared with standard care alone. However, to date, the effectiveness of sequential treatment using newer generations of fluoride varnishes has not been formally tested.

Clinical Application

Clinical application of 10% povidone-iodine is fast, easy, economical, and can be performed at every well-child visit to maintain suppression of cariogenic organisms.

Cotton gauze is used to clean the teeth, and the facial surfaces are painted with the solution. Single-use dosettes designed for dental use are inexpensive, have a long shelf life, and make application efficient. Once proficient, the process takes only a few seconds to complete prior to fluoride varnish application.

Povidone-iodine does not stain skin or mucosa and has minimal taste at the administered dosage. Parents can also be instructed to apply povidone-iodine at home using the same single-use dosettes provided in the clinic.

Safety Considerations

Potential risks associated with povidone-iodine include localized rash or swelling at the site of application. While iodine can affect thyroid function, this outcome is rare and extremely unlikely at the dosage used in this clinical context. Previous cohort studies have demonstrated no observed harms.

Ongoing Research

Two randomized controlled trials (RCTs) are currently evaluating sequential PVP-I plus fluoride varnish prevention in preschool-aged children.

• One study is being conducted at the University of Rochester (ClinicalTrials.gov Identifier: NCT05272254) and is currently in active recruitment.

• A second trial will be conducted by the National University of the Altiplano-Puno and the University of Washington in Peru and is currently in the ethics review stage.

AAPD Position

The American Academy of Pediatric Dentistry (AAPD) does not currently have a formal guideline on the use of povidone-iodine. However, it is referenced in several AAPD publications, and multiple articles discussing its use have been published in AAPD journals.

References

American Academy of Pediatric Dentistry. Guideline on fluoride therapy. Pediatr Dent. 2013 Sep-Oct;35(5):E165-8.

Amin AS, Harrison RL, Benton TS, Roberts M, Weinstein P. Effect of povidone-iodine in children with extensive dental caries. Pediatr Dent. 2004;26:5-10.

Berkowitz RJ, Koo H, McDermott M, Whelehan MT, Karp J, Billings RJ. Adjunctive chemotherapeutic suppression of mutans streptococci in the setting of severe early childhood caries. J Pub Health Dent. 2009;69(3):163-167.

Caufield PW, Gibbons RJ. Suppression of Streptococcus mutans in the mouths of humans by a dental prophylaxis and topically-applied iodine. J Dent Res. 1979 Apr;58(4):1317-26.

Chi DL, Zegarra G, Vasquez Huerta EC, Castillo JL, Milgrom P, Roberts MC, Cabrera-Matta AR, Merino AP. Milk Sweetened with Xylitol: A Proof-of-Principle Caries Prevention Randomized Clinical Trial. J Dent Child (Chic). 2016 Sep 15;83(3):152-160. PMID: 28327266; PMCID: PMC5364522.

Clark MB, Slayton RL, Section on Oral Health. Fluoride use in caries prevention in the primary care setting. Pediatrics. 2014 Sept;134(3):626-633. doi:10.1542/peds.2014-1699.

Furiga A, Dols-Lafargue M, Heyraud A, Chambat G, Lonvaud-Funel A, Badet C. Effect of antiplaque compounds and mouthrinses on the activity of glucosyltransferases from Streptococcus sobrinus and insoluble glucan production. Oral Microbiol Immunol. 2008 Oct;23(5):391-400.

Gao SS, Zhang S, Mei ML, Lo EC, Chu CH. Caries remineralization and arresting effect in children by professionally applied fluoride treatment – systematic review. BMC Oral Health. 2016 Feb 1;16(1):12.

Lopez L, Berkowitz RJ, Spiekerman C, Weinstein P. Topical antimicrobial therapy in the prevention of early childhood caries: a follow-up report. Pediatric Dent. 2002;24:204-206.

Milgrom P, Taves DM, Kim AS et al. Pharmacokinetics of fluoride in toddlers after application of 5% sodium fluoride dental varnish. Pediatrics. 2014;134:e870–e874.

Milgrom P, Tut OK, Mancl LA. Topical iodine and fluoride varnish effectiveness in the primary dentition: A quasi-experimental study. J Dent Child (Chic). 2011 Sep-Dec;78(3):143-7.

Milgrom P, Zero DT, Tanzer JM. An examination of the advances in science and technology of prevention of tooth decay in young children since the Surgeon General's Report on Oral Health. Acad Pediatr. 2009 Nov-Dec;9(6):404-9. doi:10.1016/j.acap.2009.09.001.

Moyer VA, US Preventive Services Task Force. Prevention of dental caries in children from birth through age 5 years: US Preventive Services Task Force recommendation statement. Pediatrics. 2014 Jun;133(6):1102-11.

Padilla Cáceres TC, Cervantes-Alagón S, Castillo JL, Vera Reyes CM, Rothen M, Mancl LA, Milgrom P. Using sequential applications of a novel silver diamine fluoride gel and sodium fluoride varnish to arrest severe early childhood caries lesions: A clinical trial with single group assignment. J Am Dent Assoc. 2024 Jun;155(6):526-535. doi:10.1016/j.adaj.2024.02.013. Epub 2024 Apr 25. PMID: 38678451.

Tam AI, Shemesh M, Wormser U, Sintov A, Steinberg D. Effect of different iodine formulations on the expression and activity of Streptococcus mutans glucosyltransferase and fructosyltransferase in biofilm and planktonic environments. J Antimicrob Chemother. 2006 May;57(5):865-71.

Tut OK, Milgrom P. Topical iodine and fluoride varnish combined is more effective than fluoride varnish alone for protecting erupting first permanent molars: a retrospective cohort study. J Public Health Dent. 2010;(1):1-4.

Weyant RJ, Tracy SL, Anselmo TT, Beltrán-Aguilar ED, Donly KJ, Frese WA, Hujoel PP, Iafolla T, Kohn W, Kumar J, Levy SM, Tinanoff N, Wright JT, Zero D, Aravamudhan K, Frantsve-Hawley J, Meyer DM; American Dental Association Council on Scientific Affairs Expert Panel on Topical Fluoride Caries Preventive Agents. Topical fluoride for caries prevention: executive summary of the updated clinical recommendations and supporting systematic review. J Am Dent Assoc. 2013 Nov;144(11):1279-91.

Zhan L, Featherstone JDB, Gansky SA, Hoover CI, Fujino T, Berkowitz RJ, DenBesten PK. Povidone iodine as an oral antiseptic in children with early childhood caries. J Pub Health Dent. 2006;(3):174-179.