July 2022

Aim: The study objective was to evaluate the effect of a collagen matrix (CM) in repairing and maintaining tissue thickness in palatal donor areas. Materials and methods: Ten patients requiring multiple root coverage were selected and underwent preoperative cone beam computed tomography (CBCT) (t0) to measure the palatal thickness of premolars. Connective tissue grafting (CTG) was obtained bilaterally from this site, using linear incision. The area was filled with collagen matrix (Lyostypt®) (test group) or natural blood clot (control group) and sutured. Another CBCT (t1) was performed 12 weeks later. The t0 and t1 images were overlapped to measure the palatal mucosa thickness, using the distances of 3, 6 and 9mm of the gingival margin as the reference. Results: The test group presented a smaller difference in palatal thickness between t0 and t1 at 3 and 6mm than the control group (p<0.05). In the test group, the differences were similar among the three distances measured (p>0.05), whereas the distances of 3 and 6mm in the control group presented a thickness smaller than 9mm (p=0.02). Conclusion: Use of CM in donor areas of palatal connective tissue grafts prevented loss of mucosal thickness, especially in the most critical zones (3 and 6mm).