The restoring of the periodontal tissue and reduction of inflammation are the goals of nonsurgical periodontal therapy. Studies have been completed to study the effect Chlorhexidine (CHX) has on periodontal ligament fibroblasts, the connective tissue located between the cementum and alveolar bone that aid in attachment, and ensuing biofilm production.
In a study done in 1991 (1), scientists coated extracted teeth in CHX for 3 minutes and then incubated them with fibroblasts for 1-8 hours. There was an attached cell difference between the CHX and control groups.
The CHX on the exposed root showed to significantly inhibit the fibroblasts from attaching. This indicates that CHX may interfere with regeneration of the periodontium.
The scientist’s suggestion was to minimize CHX contact with the root surface with physical barriers.
In another study completed in March 2020 (2), participants provided tongue swabs of biofilm to study the effect of CHX on microbial survival and growth. 0.12% CHX was used on in vitro oral biofilms for 3 days at 5 min each exposure.
Biofilms (the controls) that were not exposed to CHX displayed a continual growth over time. The samples that were exposed to CHX first showed a large decrease of intact cells. Those reduced cells remained stable for the following 24 and 48 hrs. even those they were exposed two more times to the CHX treatments. At 72 hrs., after three consecutive days of CHX, the concentration of bacteria rose sharply.
When used in a mouthwash procedure, short daily exposures to 0.12% CHX exhibited a repeated pattern of inactivation and rapid regrowth. Chlorhexidine is known to have antimicrobial action that continues even after the rinse is completed, the results of this study conclude that CHX only works temporarily to reduce oral biofilm bacteria.
The results of this later study who that CHX are unable to keep microbial numbers under control.
(1) Alleyn, Charles D., et al. “The Effect of Chlorhexidine Treatment of Root Surfaces on the Attachment of Human Gingival Fibroblasts In Vitro.” Journal of Periodontology, vol. 62, no. 7, 1 July 1991, pp. 434–438., doi:10.1902/jop.19126.96.36.1994.
(2) Chatzigiannidou I, Teughels W, Van de Wiele T, Boon N. Oral biofilms exposure to chlorhexidine results in altered microbial composition and metabolic profile. NPJ Biofilms Microbiomes. 2020;6(1):13. Published 2020 Mar 20. doi:10.1038/s41522-020-0124-3