Effect of topical application of chlorhexidine and metronidazole on the tissue repair of palatal wounds of rats: a clinical and histomorphometric study

Does Topical Metronidazole-Chlorhexidine Combination Gel Improve Healing of Intraoral Incisions ? A Split-Mouth Comparative Study

Background

The oral cavity is a unique environment where wound healing needs to occur in the presence of heavily contaminated oral fluid often leading to infections at the suture site. Topical antimicrobial agents have proven to be effective in controlling intraoral infections. One such antimicrobial combination is Metronidazole-Chlorhexidine which has commonly been used to treat oral ulcers and gingival inflammation; however, there are no studies of its use in the healing of oral incisions.

Methodology

This split-mouth study comprised of 15 participants who received 30 intraoral incisions. Incisions were placed either simultaneously (Group 1) or at spaced intervals (Group 2) for various minor and major surgical procedures. Metronidazole -Chlorhexidine gel was applied to the study sites while the control sites were allowed to heal naturally. Pain, inflammation, and healing were assessed using visual analogue scale and healing index by Landry et al.

Results

The study sites showed better wound healing and decreased postoperative inflammation. There was a statistically significant decrease in post-operative pain in the study site in Group 1 but not in Group 2.

Conclusion

Metronidazole-Chlorhexidine combination gel is a cost-effective, readily available, and safe medicament to improve healing of intraoral incisions and reduce post-operative inflammation and pain.

Evaluation of the Effects of Topical Application of Chlorhexidine, Ozone, and Metronidazole on Palatal Wound Healing: A Histopathological Study

ABSTRACT

This study aimed to evaluate the effects of chlorhexidine, metronidazole, and ozone application on the healing of palatal wounds in diabetic rats. A defect in the form of a 4 mm-diameter wound was created on the palatal mucosa of 84 adult female Wistar albino rats, which were randomly divided into 4 groups: control, chlorhexidine, metronidazole, and ozone groups. The animals were euthanized after 3, 6, and 10 days, and wound closure was histologically assessed. On day 3, polymorphonuclear leukocytes were significantly higher in the control group than in the chlorhexidine and ozone groups (P < 0.05). Fibrosis was higher in the ozone group than in the control and chlorhexidine groups (P < 0.05). Vascular endothelial growth factor was higher in the metronidazole and ozone groups than in the control group (P < 0.05). On day 6, the quantity of polymorphonuclear leukocytes was higher in the control, metronidazole, and chlorhexidine groups than in the ozone group (P < 0.05). Vascular endothelial growth factor was higher in the ozone group than in the control, chlorhexidine, and metronidazole groups (P < 0.05). On day 10, Vascular endothelial growth factor was higher in the control, chlorhexidine, and metronidazole groups than in the ozone group (P < 0.05). The authors concluded that the use of chlorhexidine, ozone, and metronidazole pastes resulted in enhanced wound healing, as determined histologically. The authors suggest that ozone supplementation can be an alternative therapy to chlorhexidine in impaired wound healing in diabetes mellitus.

Topical chlorhexidine, povidone-iodine and erythromycin in the repair of traumatic ulcers on the rat tongue: Clinical, histological and microbiological evaluation

OBJECTIVE

This study investigated the effect of topical application of 0.12% chlorhexidine, 10% povidone-iodine and 50% erythromycin on the optimization of healing process of traumatic ulcers made on ventral tongue of rats.

DESIGN

Forty-Eight Wistar rats were randomly divided into four groups: control, chlorhexidine (Chx), povidone-iodine (PvI) and erythromycin (Er). An ulcer of 5 mm in diameter was made on the ventral tongue of the animals. After 24 h, a microbiological sample was taken and daily application of the substances started. Six animals each group were euthanized at 4 days and the others at 8 days postoperative, totaling three and seven days of treatment. Prior to euthanasia, a new microbiological collection was performed.

RESULTS

The experimental groups showed less area of residual ulcer. A significant difference was seen between the PvI and Chx in relation to the control after three days of treatment (p < 0.05). Although the experimental groups displayed greater newly formed epithelial area, there was no significant difference compared to the control (p > 0.05). Er exhibed the lowest inflammation scores after seven days of treatment (p < 0.05). PvI showed reduction of microorganisms at both times and under aerobic (p < 0.01 at 3 days and p < 0.001 at 7 days) and microaerophilic (p < 0.05) conditions. Er significantly reduced the count of microorganisms in aerobic condition when compared to control group (p < 0.05 at 3 days and p < 0.01 at 7 days).

CONCLUSIONS

All drugs promoted reduction of the microorganisms at the site of the injury, which may have a direct effect on the tissue repair process.

PDGF-metronidazole-encapsulated nanofibrous functional layers on collagen membrane promote alveolar ridge regeneration

This study aimed to develop a functionally graded membrane (FGM) to prevent infection and promote tissue regeneration. Poly(l-lactide-co-d,l-lactide) encapsulating platelet-derived growth factor (PDLLA-PDGF) or metronidazole (PDLLA-MTZ) was electrospun to form a nanofibrous layer on the inner or outer surface of a clinically available collagen membrane, respectively. The membrane was characterized for the morphology, molecule release profile, in vitro and in vivo biocompatibility, and preclinical efficiency for alveolar ridge regeneration. The PDLLA-MTZ and PDLLA-PDGF nanofibers were 800–900 nm in diameter, and the thicknesses of the functional layers were 20–30 μm, with sustained molecule release over 28 days. All of the membranes tested were compatible with cell survival in vitro and showed good tissue integration with minimal fibrous capsule formation or inflammation. Cell proliferation was especially prominent on the PDLLA-PDGF layer in vivo. On the alveolar ridge, all FGMs reduced wound dehiscence compared with the control collagen membrane, and the FGM with PDLLA-PDGF promoted osteogenesis significantly. In conclusion, the FGMs with PDLLA-PDGF and PDLLA-MTZ showed high biocompatibility and facilitated wound healing compared with conventional membrane, and the FGM with PDLLA-PDGF enhanced alveolar ridge regeneration in vivo. The design represents a beneficial modification, which may be easily adapted for future clinical use.