Ridge preservation procedures revisited: A randomized controlled trial to evaluate dimensional changes with two different surgical protocols

The effect of different surgical techniques for ridge preservation on soft tissue parameters has seldom been investigated. The objective of this study was to compare the effect of two different ridge preservation techniques on soft and hard tissue dimensions.Thirty patients requiring tooth extraction were randomly allocated to either control group C (allograft covered with a non-crosslinked collagen membrane with primary closure) or experimental group E (allograft covered with cross-linked collagen membrane left exposed). Sites were surgically re-entered at 6 months. Soft and hard tissue measurements, cone beam computed tomography (CBCT), and cast measurements were taken at baseline and 6 months.Twenty-eight patients were included in this analysis. When the two treatment groups were compared, the width of the buccal keratinized tissue in the E group showed an increase of 0.43 ± 0.42 mm compared to net loss of 1.57 ± 0.51 mm for the C (P = 0.006). Similarly, buccal tissue thickness has increased in the E group 0.46 ± 0.22 mm compared to a loss of 0.15 ± 0.23 mm in the C group (P = 0.068). Volumetric assessment of the changes in the alveolar ridge for the E group showed a slight decrease (68.3 ± 17 mm3) whereas the C group has experienced almost double this loss (107.5 ± 11 mm3; P = 0.07). Crestal width, measured on the CBCT scan, has shown significant reduction in the C group (4.18 ± 0.56 mm) compared to only 1.74 ± 0.4 mm in the E group (P = 0.003).Crosslinked collagen membrane with allograft placed intentionally non-submerged resulted in better preservation of the keratinized tissues (width and thickness) with similar and at times better osseous preservation following extraction.