Early Healing of Oral Soft Tissues: a Clinical and Biomolecular Analysis. Part II

Early Healing of Oral Soft Tissues: a Clinical and Biomolecular Analysis. Part II - Effect of Local Chlorhexidine Administration in Gene Expression and Cellular Behaviour 24-hours After Injury

The purpose of the present study is to evaluate the influence of the post-surgical chlorhexidine indication in the gene expression profile and cellular behavior in the early wound healing process -24 hours after injury- of the oral soft tissues. The main hypothesis is that the post-surgical use of chlorhexidine affects the gene expression and the celular behavior in the early wound healing process of the soft oral tissues.

The bacterial infection control in the wound healing is a very important aspect to considerer. Local antiseptic administration after the surgical procedures has been used to control the bacterial contamination. Chlorhexidine (CHX), widely used as antiseptic, especially as post-surgical indication, has a toxic effect both in vivo and in vitro and their influence on wound healing has been studied for a long time. One of the first animal studies, in 1980, concluded that intensive rinsing with high concentrations of chlorhexidine after oral surgical operations, could result in delay and disturbance of wound healing. Another more recent animal study concluded that CHX induces apoptosis or necrosis in the fibroblasts. Mariotti and Rumpf, in 2016, carried out a studied incubating human gingival fibroblasts in CHX. The results have been suggested that chlorhexidine could induce a dose dependent reduction in cellular proliferation and that concentrations of chlorhexidine that have little effect on cellular proliferation can significantly reduce both collagen and non-collagen protein production of human gingival fibroblasts in vitro. Hence, the introduction of commercially available concentrations (0.12%) or diluted commercial concentrations (as low as 0.00009%) of chlorhexidine to surgical sites for short periods of time prior to wound closure can conceivably have serious toxic effects on gingival fibroblasts and may negatively affect wound healing. All the previous mentioned studies permit understand that the CHX is not harmless to the oral tissues. However, its effect is not entirely clear and should be evaluated in depth taking into account that it is one of the most indicated antiseptics after surgery. Currently, there are no studies that evaluate if the post-surgical use of CHX affect the gene expression in the early wound healing.

early wound healing, real-time polymerase chain reaction, gingiva, oral mucosa, palatal tissue, Chlorhexidine

periodontal surgery + post-surgical CHX mouth-rinses + buccal attached gingival (G) biopsies 24 hr after surgical procedure

Periodontal surgery will be performed and 24 hr after the surgical procedure a 2mm punch biopsy will be harvested at the level of the buccal attache gingiva (G).

Changes from baseline fold regulation wound healing related genes at 24 hours after post-surgical chlorhexidine use.

Total RNA from biopsies or cell cultures was extracted using TRIzol reagent Quantitative real-time PCR (qRT-PCR) cDNA was generated and cDNA obtained were used for amplification of wound healing related genes using the appropriate TaqMan gene expression assay kits.

Assessed with a clinical index (EHS- Early wound healing score). This score assessed clinical signs of re-epithelialization (CSR), clinical signs of haemostasis (CSH), and clinical signs of inflammation (CSI). Since complete wound epithelialization was the main outcome, the CSR score was weighted to be 60% of the total final score. Accordingly, a score of 0, 3, or 6 points was possible for the assessment of CSR, whereas scores of 0, 1, or 2 points were possible for CSH and CSI. Higher values indicated better healing. Accordingly, the score for ideal early wound healing was 10.

Inclusion Criteria: patients that required periodontal surgery; patients age between 30-60 years; patients with full mouth plaque score and full mouth bleeding score < 15%; patients with a good general healthy status; patients without any medicaments or drug consumption that can affect the healing process; non-smoking patients. Exclusion Criteria: patients in pregnancy; patients in lactation period; patients with consumption of antibiotics or anti-inflammatory drugs in the previous six months; patients with systemic diseases.

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