Extraction Socket Healing in Humans After Ridge Preservation Techniques: Comparison Between Flapless and Flapped Procedures in a Randomized Clinical Trial

• Autores: Antonio Barone
• Localización: Journal of periodontology, ISSN 0022-3492, Nº. 1, 2014, págs. 14-23
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • 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.

    The alveolar process is a tooth-dependent structure, and its development is strictly connected with tooth eruption.1 Several changes occur after tooth extraction, including loss in height and width of the alveolar bone.2-4 This resorption process causes relocation of the ridge to a more palatal/lingual position.4 Implant therapy can be considered successful only when functional and esthetic requirements have been accomplished. Therefore, both adequate alveolar bone volume and favorable alveolar ridge architecture are important considerations to obtain a positive functional and esthetic rehabilitation.4-6 Moreover, knowledge about the extraction healing process and preservation of the alveolar ridge volume is essential in treatment planning.5,7,8 Socket preservation procedures have been performed to preserve hard and soft tissue volume, which can be partially lost after tooth removal. These procedures allow for wider and longer implant placement compared with non-augmented sockets and reduce the need for simultaneous augmentation procedures at the time of implant placement.4,5 The use of various techniques and biomaterials has been proposed over a number of years to maintain the anatomic dimensions of the alveolar ridge after tooth extraction. No significant differences have been shown among the different biomaterials used, although collagen seems to be unsuitable to counteract tissue changes after tooth extraction.8,9 The biomaterials used in ridge preservation maintain space and promote bone growth, primarily through their osteoconductive activity; graft resorption and new bone formation may differ significantly among osteoconductive materials.1,10-13 A recent randomized clinical trial assessed that the alveolar ridge preservation technique was able to limit contour changes after tooth extraction.14 The authors showed that despite the observed benefit of this procedure, vertical and horizontal bone loss could be expected.14 The use of a membrane and graft material for ridge preservation procedures requires primary closure with a large full-thickness flap.8,15-17 The elevation and advancement of a full-thickness flap can cause postoperative bone resorption; in addition, flap elevation has been associated with marginal recession at the adjacent teeth, defective papillae, and loss of keratinized mucosa.

    Although studies have suggested that wound dehiscence and membrane exposure could result in infection and lack of bone formation,18 more recent studies show that the intentional exposure of bioabsorbable membranes does not seem to adversely affect guided bone regeneration procedures when used to treat fresh extraction sockets.14,19 The amount of bone resorption occurring after flap and flapless procedures is still controversial; some authors reported less pronounced bone remodeling of the alveolar ridge after socket preservation with a flapless approach.20,21 However, other authors did not report any significant difference between flapless and flapped approaches.22 The objective of this study is to investigate and compare the effect of soft tissue primary closure on tissue changes of extraction sockets grafted with a xenograft and a collagen membrane. The soft and hard tissue evaluations of grafted extraction sockets, where a mucoperiosteal flap was coronally moved to obtain soft tissue primary closure, were compared with those of extraction sockets where no flap was raised and the collagen membrane was left intentionally exposed to the oral cavity. The present study reported clinical outcomes up to 3 months after grafting. Furthermore, to evaluate the success of the procedure over time, the patients were to receive follow-up until the fifth year. The present study is reported according to the Consolidated Standards of Reporting Trials (CONSORT) guidelines.