Evaluation of PerioPatch™ for soft tissue healing. An animal study

Objectives: to test the effect of PerioPatch™ on soft tissue wound healing in an animal model.
Methods: Each maxillary side of 48, 6-month-old Wistar rats, served as a sample. A mid-crestal incision was made in the existing edentulous area between the 1^st molar and the incisors. A full thickness flap was raised on either side of the incision and then repositioned and sutured. A patch was placed following surgery and was replaced every 12 hours for following 3 days. Half of the animals were sacrificed after 5 days (X₅) the remaining after 12 days (X₁₂). Eight groups:- A₅, A₁₂ -Study groups - PerioPatch™ placed on incision line; B₅, B₁₂ – A placebo patch C₅, C₁₂ -Negative control – No patch D₅, D₁₂ - Intact control group – No surgery and no patch used. Soft tissue biopsies for histological and immunohistological evaluation.
Results: a split-mouth design (A-C, A-D, B-C, B-D( and time since operation (5 or 12 days), two-way ANOVA test was used. Epithelial gap - A significant increase in epithelial gap delta was found from day 5 to day 12 (p=0.045). PSR ratio - Statistically significant effect for group comparison (p<0.001). CD68-No significant effect. Ki 67- A marginal significant interaction between group comparison and time was found (p=0.05). TG II - Significant effect for group comparison (p=0.044). The effect of patch type (A or B( and operation (vs. no operation) on dependent measures: Epithelial gap - After 5 days, a statistically significant effect was obviously found for operation (p=0.017). After 12 days a significant interaction between patch type and operation was found (p=0.056). PSR ratio - After 5 days a significant effect was found for patch type (p<0.001). After 12 days a significant effect was found for patch type (p<0.001). CD68 ratio - No significant effects were found. Ki67 - After 12 days a significant effect was found for patch type and operation (p=0.033). TGII - After 12 days a significant effect was found for patch type (p=0.014).
Conclusions: Patch A improved wound healing in the described model. Its effect was exerted by significantly decreasing epithelial gap following surgery, and was accentuated with time. It was mediated through increased cellular proliferation, collagen production and vascularity.