Chlorhexidine (CHX)

Chlorhexidine is the most effective antiseptic and is considered the gold standard.

  • Powerful antiseptic with anti-plaque, anti-gingivitis and antibacterial activity.
  • Broad spectrum of action against gram+ and gram- bacteria, aerobes and anaerobes and even fungi and yeasts.
  • High substantivity: actively released gradually over 8-12 hours, ensuring prevention against bacterial recolonisation.
  • Diverse formulations to cover all phases of periodontal care, including treatment, long-term maintenance and prevention.

Structure

This compound is a strong dicationic base with two positive charges on either side of the Hexamethylene Bridge, making it extremely interactive with anions. CHX remains more stable in the form of salt and the most common preparation is digluconate salt because of its high aqueous solubility. 1
estructura CHX

Mechanism of action

1. Prevents the formation of a new acquired pellicle, reducing the adsorption of salivary glycoproteins to the tooth surface, by blocking free acid groups, such as sulphates, carboxyls and phosphates 2,3,4,5
2. Prevents bacteria from binding to the already formed acquired pellicle, through negative groups of the bacterial cell surface (i.e. teichoic acids) 1,4,7,8
3. Disrupts the structure of existing bacterial plaque. CHX displaces the calcium from the sulphate groups of the plaque, therefore disrupting its structure, which in turn prevents bacteria from binding to the acquired pellicle. 3,4

Chlorhexidine’s mechanism for binding to oral mucosa and possible release mechanism from salivary calcium displacement.

Substantivity

The adsorbed CHX is actively released gradually over 8-12 hours4. After 24 hours, low concentrations of chlorhexidine can still be recovered, preventing bacterial colonisation during this time 7,8, 9

Its high substantivity is due to the fact that it adsorbs quickly to the bacterial surface, because of its neutral and slightly alkaline pH. It binds to the bacteria in plaque, to tooth enamel and to the acquired pellicle that covers teeth, and is slowly released, causing negative effects on the bacterial cytoplasm and impeding pathogenic survival.

The CHX molecule adheres to the mucosa by binding to the carboxyl groups present in the mucin layer surrounding the mucosa. Subsequently, due to the segregation of calcium ions by the salivary glands, chlorhexidine molecules are released slowly.

Chlorhexidine’s mechanism for binding to oral mucosa and possible release mechanism from salivary calcium displacement.

Concentrations

Jenkins et al. (1989), conclude that the anti-plaque activity of CHX is more due to the formulation (concentrations and processes) than to the concentration of CHX used10.

Indications

  • Adjunct to mechanical biofilm control
  • Prevention and treatment of gingivitis, periodontitis, peri-implant mucositis and peri-implantitis
  • Adjunct to scaling and root planing
  • Patients at high risk for caries, root caries and polycaries
  • Pre- and post-surgery
  • When used CHX in gel form with a surgical toothbrush, reduces the possibility of complications during healing and minimises the risk for infection 11,12
  • To reduce plaque formation and improve gingival health around implants
  • After extractions, reduces the risk for alveolitis
  • Prior to or during in-office prophylaxis, significantly reduces inflammation and bleeding
  • Immunocompromised patients with oral complications
  • Patients undergoing radiation or chemotherapy
  • To reduce recurrence and severity of oral ulcers
  • Patients who have difficulty carrying out proper mechanical hygiene (physical and mental disabilities)
  • Medically compromised patients, to improve plaque control and prevent complications (Candida spp).
  • To reduce plaque and improve gingival health in people with braces
  • Patients with removable prosthetics
  • Treatment of oral halitosis 13

Instructions for use

It is advisable to rinse with CHX after brushing with CHX gel. It is advisable not to rinse with water immediately after rinsing with CHX, because this may reduce its substantivity and enhance its bitter taste.

Instructions for active periodontal treatment (0.12% CHX):

Rinse with 15 ml, 2 times per day for 30 seconds (morning and night after brushing); for a period of 15 days or 1 month depending on the clinical condition.

Can be diluted in water for oral irrigation on a 1:1, 2:1 or 5:1 ratio of water and mouthwash, respectively.

Instructions for periodontal maintenance (0.05% CHX):

Rinse with 15 ml, 2 times per day for 30 seconds (morning and night after brushing); for a period of 3 to 6 months depending on the clinical condition.

Treatment instructions prior to surgical intervention:

Rinse with 15 ml for 30 seconds before the intervention.

Treatment instructions after surgical interventions:

During the days following the intervention, rinse with 15 ml every 12 hours.

Contraindications and interactions

The CHX molecule can be partially or completely deactivated when the formulation (concentrations and processes) is not adequate 14 or when sodium fluoride exists in the same formula (11,15,16,17).

Another important interaction occurs between CHX and sodium lauryl sulphate, an excipient used in numerous toothpastes, which is why toothpastes containing sodium lauryl sulphate are recommended to be used at least 30 minutes before applying CHX 18,19.

Do not use in case of allergy to CHX.

Side effects

Its most common side effect is the brown staining to teeth, some restoration materials and mucosa, mainly on the tongue dorsum. Staining or discolouration may be caused by the interaction between CHX salts in the mouth and the tannins present from some substances (coffee, tea, wine, etc…), although concentration and dose should not be overlooked20. Even so, staining does not seem to penetrate deep into the surface, and can therefore be easily removed with a professional prophylaxis. Tooth staining may be a good indicator of patient treatment compliance.

Another side effect that is frequently described is a change in taste perception, which may be reduced by not rinsing with water after rinsing with CHX. This effect disappears completely once the treatment has been completed.

Other possible adverse events include the occurrence of mucosal desquamation and irritation, particularly with high CHX concentrations, which vanish after the treatment has been completed21.

Toxicity

Because CHX is hardly absorbed in the gastrointestinal tract, accidental ingestion of the solution rarely produces systemic effects or allergic reactions from CHX.

References:

  1. Fardal O, Turnbull RS. A review of the literature on use of chlorhexidine in dentistry. J Am Dent Assoc. 1986 Jun;112(6):863-9.
  2. Lang N, Brecx M. Clorhexidine digluconate, an agent for chemical plague control and prevention of gingival inflammation. J Periodont Res 1986; 21 (Suppl.): 74-89.
  3. Pader M. Oral hygiene products and practice. 1988; Marcel Dekker Inc. , New York. 319-329.
  4. Greenstein G, Berman C, Jaffin R. Chlorhexidine. An adjunct to periodontal therapy. J Periodontol. 1986 Jun;57(6):370-7.
  5. Rölla G, Melsen B. On the mechanism of the plaque inhibition by chlorhexidine. J Dent Res. 1975 Jun;54 Spec No B:B57-62.
    World workshop in clinical periodontics, Princenton, New Jersey. July 23-27 1989.
  6. Yankell SL, Moreno OM, Saffir AJ, Lowary RL, Gold W. Effects of chlorhexidine and four antimicrobial compounds on plaque, gingivitis, and staining in beagle dogs. J Dent Res. 1982 Sep;61(9):1089-93.
  7. Case DE. Safety of Hibitane (I) Laboratory Experiments. J Clin Periodontol 1977;4:66-72.
  8. Bonesvoll, P. Lokkeb, P. Rolla, G. And Paus, P. N. Retention of chlorhexidine in the human oral cavity after mouth rinses. Arch Oral Biol, 1974; 19:209.
  9. Jenkins S, Addy M, y Newcombe RG. Comparison of two commercially available chlorhexidine mouthrinses: II Effects on plaque reformation, gingivitis, and tooth staining. Clin Prev Dent. 1989 Nov-Dec;11(6):12-6.
  10. Bascones A, Morantes S. Antisépticos orales. Revisión de la literatura y prospectiva actual. Av Periodon Implantol 2006;18,1:31-59.
  11. Noguerol B, Sanz M, Follana N, Bascones A. Eficacia de un cepillo dental ultrasuave en el post operatorio de la cirugía periodontal. Revista Periodoncia 1991; 1(1)
  12. Van den Broek, Fenstra L, de Baat C. 2008. A review of the current literatura on management of halitosis. Oral Dis. 14:30-39.
  13. Addy M, Wade WG, Jenkins S y Gooldfield S. Comparison of two commercially available chlorhexidine mouthrinses: I stainning and antimicrobial effects in vitro. Clin Prevent Dent 1989; 11: 10-4.
  14. Mendieta C, Vallcorba N, Binney A, Addy M. Comparison of two chlorhexidine mouthwashes on plaque regrowth in vivo and dietary staining in vitro. Journal of Clinical Periodontology. 1994: 21: 296-300.
  15. Steenberghe V, Quiryne M, Avontroodt P, Peeters W, Pauwels M, Rouche W. Effect of different chlorhexidine formulations in mouthrinses on de novo plaque formation. J Clin Periodontol 2001;1127-36.
  16. Saliba de Freitas C; Oliveira Diniz HF; Gomes JB; Dário Sinisterra R; Corté ME. Evaluation of the substantivity of chlorhexidine in association with sodium fluoride in vitro. Pesqui. Odontol. Bras 2003; 17 (1): 78-81.
  17. Barkvoll P. Interaction between chlorhexidine igluconate and sodium lauryl sulfate in vivo. J Clin Periodontol 1989, 16:593-95.
  18. Van Strydonck, Timmerman MF, Van der Velden U, Van der Weijden GA: The anti-plaque efficacy of a chlorehexidine mouthrinse used in combination with toothbrushing with dentifrice. J Clin Periodontol 2004; 31:691-5.
  19. Addy M, Moran J y Newcombe R. A comparison of 0,12% and 0,1% chlorhexidine mouthrinses on the development of plague and gingivitis. Clin Prevent Dent 1991; 13:26-9.
  20. Gjermo P, Bonesvoll P, Rolla G. Relationship between plaque inhibiting effect and retention of clorhexidine in the human oral cavity. Arch Oral Biol 1974;19:1031-4.