Anti-Infective Agents in Periodontal Treatment

Jorgen Slots, DDS, DMD, PhD, MBA


September 15, 2011

In This Article

Antiseptic Agents in Periodontal Disease

An increase in antibiotic-resistant bacteria has created interest in using inexpensive, safe, and highly bactericidal/virucidal antiseptics in periodontal therapy.[4] Antiseptics attack multiple components of infectious agents, practically eliminating the risk for development of resistance, and do not interact with prescription medications. Antiseptics are particularly valuable in the treatment of biofilm infections, which may be unresponsive to even high concentrations of antibiotics. Moreover, because the contents of inflamed periodontal pockets are emptied into the oral cavity every 90 seconds, and relatively small amounts of antimicrobial agents are applied subgingivally, the risk for antiseptics entering the gingival tissue and causing systemic damage is virtually nonexistent. This high degree of safety allows frequent and broad use of antiseptics in periodontal treatment.


Aqueous (Lugol's iodine) and tincture (iodine in alcohol) solutions of iodine have been employed as dental antiseptics for more than 150 years, but the early iodine formulations caused surface staining and irritation of mucosa and skin. Iodophors (iodine-releasing agents) developed in the 1950s were solutions of iodine complexed with an organic carrier that largely overcame the negative aspects of iodine treatment. The most common commercial form of povidone-iodine (Betadine® or generic equivalent) is a 10% solution in water, yielding 1% (10,000 ppm) available iodine. Povidone-iodine can give rise to allergic reactions, including itching, burning, and reddening and blistering in the area of application, so a patient's history of allergy to iodine or shellfish must be evaluated. Prolonged iodide intake can inhibit thyroid hormone synthesis and cause goiter, myxedema, or hyperthyroidism; therefore, povidone-iodine should not be used in patients with thyroid dysfunction, pregnant woman, infants, or in routine patient self-care.

Povidone-iodine kills in vitro all major periodontopathic bacteria within 15 to 30 seconds and exhibits a wide virucidal spectrum, covering both enveloped (eg, herpesviruses) and non-enveloped viruses. Several studies have shown a measurable improvement in periodontal status after treatment with full-strength povidone-iodine.[4] A study from Sweden[5] showed that patients who received a whole-mouth application of povidone-iodine at the time of initial therapy exhibited less periodontitis for up to 13 years after treatment.

Povidone-iodine lavage together with thorough debridement of necrotic tissue has arrested the progression of noma in HIV-infected patients.[6] Of potentially great clinical significance, povidone-iodine can kill the major cariogenic bacterium Streptococcus mutans, and caries-prone children who received a povidone-iodine application to their entire dentition every 2-3 months experienced a marked reduction in new caries lesions compared with control children.[7]

Povidone-iodine used in periodontal treatment is applied subgingivally using, for example, a 3-mL endodontic syringe with a 23-gauge cannula that has a blunt end and side ports. The cannula is inserted into the base of the periodontal pocket to ensure maximum drug delivery. A single course of subgingival irrigation of the entire dentition takes about 1.5 minutes and is repeated at least 3 times for a total application time of 5-10 minutes.

Sodium Hypochlorite

Sodium hypochlorite (NaOCl) is a highly active cytotoxic oxidant recognized to be among the most potent antiseptic and disinfectant agents against bacteria, fungi, and viruses. Sodium hypochlorite occurs naturally in human neutrophils and monocytes/macrophages[8];] therefore, it does not evoke allergic reactions; it is not a mutagen, carcinogen or teratogen; and it has a century-long safety record. Dilute sodium hypochlorite has no contraindications. Sodium hypochlorite is available globally at exceptionally low cost as household bleach in concentrations of 5%-6%.

Sodium hypochlorite has been used as an antiseptic agent in dentistry for more than a century and remains a widely used root canal irrigant at concentrations ranging from 1.0%-5.25%.[9] Sodium hypochlorite rinsing exerts broad antimicrobial activity against experimental oral biofilms and reduces biofilm by 80-fold compared with water.[10] Dilute sodium hypochlorite rinse (0.5%) has produced a 47% greater reduction in dental plaque mass compared with water rinsing.[11] Low gingivitis scores were maintained around teeth receiving sodium hypochlorite rinse, whereas the gingivitis score increased by 50% in control teeth.[11]

The American Dental Association Council on Dental Therapeutics has designated dilute sodium hypochlorite a "mild antiseptics mouth rinse" and suggested its use for direct application to mucous membranes.[12] The lowest concentration of sodium hypochlorite solution that reliably inactivates bacteria in vitro is 0.01%.[13] Patients are advised to use an oral irrigator for subgingival application of sodium hypochlorite at a concentration of 0.5%. This is equivalent to 10 mL (2 teaspoonfuls or two thirds of a tablespoon) of 6% household bleach in 125 mL (one half glass) of water.

Patients are also advised to rinse orally with 0.2% sodium hypochlorite for 30 seconds, 2 or 3 times per week. This is equivalent to 8 mL (2 reduced teaspoonfuls) of 6% household bleach in 250 mL (a full glass) of water. More frequent rinsing may produce a brown-black extrinsic discoloration of the teeth. Diluted hypochlorite solutions gradually lose strength, so fresh solutions should be prepared for each use.


Chlorhexidine, a bisbiguanide, has been an important oral antiseptic for more than 40 years, and numerous studies and meta-reviews have confirmed its antiplaque and antigingivitis effects.[14] The ability of chlorhexidine to adhere to the dental pellicle and oral mucosa prolongs its antiplaque effect. Chlorhexidine gluconate is used in dentistry as a 0.12%-0.2% mouthwash applied in a volume of 15 mL for 30 seconds. Low-cost generic chlorhexidine in concentrations of 2% or higher can be diluted in water to the desired concentration for oral use.

Chlorhexidine is inactivated by organic serum compounds in the gingival crevice fluid, and subgingival placement produces little change in microbial and clinical variables.[15] As the antimicrobial action of the cationic chlorhexidine is neutralized by anionic compound surfactants in toothpastes, chlorhexidine should not be used in conjunction with toothbrushing. A major disadvantage of chlorhexidine is its propensity to dark stain tooth surfaces. Dark staining gaps along the margin of tooth-colored restorations may reflect into the filling material and necessitate replacement of affected restorations.


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