The subepithelial connective tissue graft (CTG) is a common and predictable modality in the treatment of gingival recession. While CTG is widely used, little is known about its early healing, considered critical for success. The aim of this prospective study was to assess CTG revascularization, tissue thickness, and molecular changes during early healing.
Adult (18-55) healthy non-smokers scheduled to receive CTG were recruited. Buccolingual tissue thickness was recorded at 6 sites over the grafted area using a probe inserted into a custom stent. Blood flow was determined using laser Doppler Flowmetry (LDF) at the surgical recipient site (CTG site) and at a control site outside of the surgical area. Gingival crevicular fluid (GCF) was collected at mesial and distal interproximal sites of CTG and control sites. Blood was obtained from the antecubital vein pre-operatively and at 3 days post operatively. LDF, thickness measurements, and GCF samples were collected pre-operatively, immediately postoperatively (except for GCF), and at 3, 7, 14, and 21 days postoperatively. After processing, GCF and serum samples were used to measure angiogenin (ANG) levels by a commercially available ELISA assay.
13 subjects completed the study. Immediate postoperative graft thickness averaged 1.5 mm. Compared to immediate postoperative thickness, tissue thickness increased 102% on day 3, returning to baseline by day 21. LDF measurements showed 87% reduction in tissue perfusion immediately post-surgery compared to pre-operative values. At postoperative day 3, tissue perfusion was reduced by 74%, recovering by day 7. At 3 days postoperatively, GCF ANG levels increased to 201% of baseline in CTG sites, and remained unchanged in control sites and serum. GCF ANG levels showed no significant change from pre-operative levels on postoperative days 7, 14, and 21. Significant differences in blood flow and ANG levels were observed when subjects were subgrouped by age. Subjects aged >35 years (n=6) showed an 80% reduction in blood flow at day 7 and GCF ANG levels were 248% of baseline at day 3, while the corresponding changes in subjects aged <35 years (n=7) showed a 120% increase in blood flow at day 7 and GCF ANG levels were 161% of baseline at day 3.
CTG treated sites undergo significant thickness changes during early healing, with tissue thickness doubling at day 3 and requiring 2 weeks of healing to return to baseline. CTG perfusion is significantly reduced until one week postoperatively, with older subjects exhibiting reduced perfusion until 2 weeks postoperatively. GCF ANG concentration was significantly increased in the very early healing period (day 3) with a return to baseline levels at one week, with older subjects exhibiting greater increases. To our knowledge, this is the first study to document the early tissue thickness changes following CTG treatment and to suggest that age may impact early CTG healing, i.e., tissue perfusion and local molecular changes.