Bacterial community shifts during healing of palatal wounds: comparison of two graft harvesting approaches

Objectives: The aim of this study was to investigate the postoperative healing and microbial profile of donor sites of routine and pre-wounded free gingival grafts (FGGs).

Methods: Ten volunteers, recruited into a split mouth study, had one side of the palate pre-wounded. Five days later, grafts were harvested from both the pre-wounded and the contra-lateral site (routine graft). Wound healing was assessed on postoperative day 3, 7, 14 and 21. Microbiological samples were collected at baseline, graft harvest and the aforementioned postoperative days, and analysed by terminal restriction fragment length polymorphism for bacterial community profiling.

Results: On postoperative day 14, 0% of routine and 40% of pre-wounded sites exhibited epithelial closure; 90% of routine and 30% of pre-wounded sites were painful on day 7. Microbial profiles differed significantly between routine and pre-wounded sites at graft harvest and postoperative days 3 and 7. The number of bacterial species increased from surgical intervention to closure. While the number of species in pre-wounded sites was similar from harvest to day 7, the number in routine sites increased. The Shannon diversity and equitability indices showed statistically significant differences between routine and pre-wounded sites for days 3 and 7.

Conclusions: Pre-wounding FGG donor sites might accelerate the healing course and wounding the palate was associated with significant bacterial community shifts.