Extraction socket healing in humans after ridge preservation techniques: comparison between flapless and flapped procedures in a randomized clinical trial.

BACKGROUND The preservation of hard and soft tissue volume, partially lost after tooth removal, can potentially reduce the need for the more demanding augmentation procedures used in implant-supported rehabilitation. The objective of this research study is to investigate the effect of filling with xenogeneic material the postextractive sockets of two surgical procedures (flapless versus flapped). METHODS In this prospective randomized clinical survey, two types of socket preservation were performed on two groups of patients: the control, treated via full-thickness mucoperiosteal flap, and the test, via a flapless procedure. Anatomic measurements and related outcome variables at the third month were analyzed using multiway analysis of variance. Multiple comparison tests, using Tukey honestly significant difference test, and appropriate pairwise comparison tests for independent samples were carried out. RESULTS Sixty-four patients were treated, 32 for each of the two socket preservation procedures. Statistically significant differences were registered for the output variables -- changes in width of keratinized gingiva, changes in bucco-lingual width, and vertical bone changes at four sites -- between the two socket preservation techniques, with P values of <0.001, <0.001, and 0.0105, respectively. CONCLUSIONS A full-thickness mucoperiosteal flap gave significantly more negative results than that of the less-demanding flapless procedure, with an increased width resorption of the postextraction site. Moreover, the increased value of the keratinized gingival width attested to the positive outcome of a flapless procedure in terms of soft tissue preservation and improvement. On the other hand, the flapped technique seemed to show less vertical bone resorption on the buccal aspect than the flapless technique.