Chlorhexidine in Dentistry: Pharmacology, Uses, and Adverse Effects

Abstract

Objectives: The aim of this work was to review the current uses of chlorhexidine (CHX) in dentistry based on its mechanism of action, whilst highlighting the most effective protocols that render the highest clinical efficacy whilst limiting adverse drug reactions.

Methods: A literature search was conducted using the key words chlorhexidine, mechanism of action, adverse effects, and dentistry using databases in the University of Toronto library system. The titles and abstracts were read, and relevant articles were selected.

Results: A total of 1100 publications were identified, 100 were investigated, and 67 of them were used. Out of the 67 selected articles, 12 were reviews on CHX; 5 articles focussed on CHX gels; 13 focussed on CHX mouthwashes; 8 focussed on CHX products; 13 discussed adverse effects associated with CHX; 13 focussed on periodontal pathology and treatment; 6 focussed on implant periodontal and dental surgeries; 7 evaluated effects on caries; 6 looked at the mechanisms of action; and 12 focussed on the antibacterial and antimicrobial impact on the oral biome. There were multiple areas of overlap amongst the articles, and results showed that CHX provides different uses, but mainly as an adjunct to various treatments. Mouthwash was the most superior medium when used in short time spans when mechanical prophylaxis was not possible for the prevention of gingivitis and maintenance of oral hygiene. CHX products are often used in periodontics, post-oral surgical procedures, and as a prophylaxis for multiple invasive procedures with minimal adverse effects. Tooth staining was the most negative adverse effect reported by patients.

Conclusions: CHX's antimicrobial properties make it an ideal prophylactic when mechanical debridement is not possible. CHX mouthwash appears to be more effective compared to gels. Concentrations of 0.12% to 0.2% are recommended; any mouthwash with concentrations above 0.2% will unnecessarily increase the unwanted side effects. CHX is useful amongst various areas of dentistry including oral surgery, periodontics, and even general dentistry. For long-term treatments, especially in periodontitis patients (stage I-III) undergoing nonsurgical treatments, CHX chips are recommended. CHX chips are also recommended as an adjunct to implant debridement in patients with peri-implant mucositis and peri-implantitis over CHX mouthwash and gels.

Keywords: Adverse effects; Chlorhexidine; Dentistry; Mechanism of action.

Figure

Mechanism of action (MOA) for chlorhexidine. Stage 1: Positively charged chlorhexidine is attracted to the negative charge on the bacterial cell wall., , Stage 2: Chlorhexidine forms specific and strong adsorption to phosphate-containing molecules that are on the surface of the bacterial cell.^, Stage 3 (bacteriostatic): Penetration through the bacterial cell wall occurs, damaging it and compromising its integrity. The result is an outflow of low-molecular-weight cytoplasmic components, such as potassium ions, and inhibition in the activity of some of the enzymes associated with the cytoplasmic membrane. Stage 4 (bactericidal): Cytoplasmic coagulation and precipitation occur by forming complexes with phosphorylated compounds, such as adenosine triphosphate (ATP) and nucleic acids.^,,