The physiologic changes after tooth extraction lead to soft and hard tissue deficiencies. These influence the appearance of the prosthetic restoration and the peri-implant tissues.1
In the past, these deficiencies were treated through bone regenerative techniques. But, more recently, bone regeneration has been combined with soft tissue grafting, to achieve a better volume gain and to restore the contours of the alveolar ridge.2
Soft tissue thickness matters
Soft tissue thickness influences the translucency and color of the peri-implant tissues. But recent data have also shown that Areas with thick soft tissues may be less prone to the initial bone loss associated with the establishment of the biologic width.3 Thus, soft tissue grafting has become a common procedure when treating aesthetically demanding situations.
Soft tissue harvesting
Connective tissue grafts increase soft tissue contours and improve the harmony between restorations and adjacent tissues.4 The most frequent donor sites are the anterior and posterior parts of the palate, including the maxillary tuberosity. But, the harvest site may influence the thickness of the graft. Thus, the selection of the harvest site must be based on the amount of tissue needed.5(Fig. 1) Clinicians tend to harvest grafts with greater proportions of lamina propria, since it is believed to be more stable compared to glandular or fatty tissue. Graft thickness has been directly correlated with the amount of pain perceived by patients.6
Fig. 1A: Site 25 presents with an implant supported restoration. Patient complains of grayish color of the mucosa and poor esthetics. Diagnosis reveals no signs of peri-implant pathology.
Fig. 1B: Lateral image reveals signifi cant ridge deformity.
Fig. 1C: Tunnel preparation is performed, and autogenous soft tissue from the tuberosity is grafted in the area.
Fig. 1D: Autogenous graft is fi xed in the transition zone between implant shoulder and mucosal margin.
Fig. 1E: Final reconstruction of implant in position 25 and full coverage restoration in 26.
Fig. 1F: Occlusal view 24-months after final restoration.
Fig. 1G: Lateral view revealing improved soft tissue contours.
A new alternative to autologous grafts
Autologous grafts are associated with a greater number of post-surgical complications. These include bleeding and pain. There is great interest in the scientific community to develop soft tissue substitutes that achieve similar outcomes, but reduce morbidity.
Currently, researchers are testing a new 3-D collagen matrix, that has been designed to increase the quantity of soft tissue around implants. A recent publication has shown promising results for this matrix when compared to autologous connective tissue.7(Fig. 2)
Fig. 2A: Ridge deformity after implant placement at site 22 with simultaneous ridge augmentation.
Fig. 2B: Soft tissue volume augmentation procedure. Geistlich Fibro-Gide® is applied over the buccal aspect. An island flap is performed in the palatal aspect to ensure passive soft tissue closure.
Fig. 2C: 4-months after soft tissue augmentation, occlusal image reveals improved soft tissue contours.
Flap techniques
Conventional flaps or tunnel preparations are the most common flap techniques in the available literature. Conventional flaps allow for better access and graft fixation. Tunnel preparations have the advantage of better preserving papillae height. Regardless of the surgical technique, it is important that the soft tissue graft or substitute be fixed in the area most likely to create a benefit: the transition zone from the implant shoulder to the gingival margin.
Importance of keratinized mucosa around dental implants
Besides the thickness of the peri-implant tissues, the width of keratinized tissue has received significant attention. A reduced width of keratinized mucosa may be more prone to lingual plaque accumulation, bleeding on probing and buccal soft tissue recession.8 Considering the available data, clinicians should consider procedures aimed at preserving keratinized tissue. When there is significant displacement of the mucogingival junction after GBR treatments, keratinized tissue augmentation procedures should be considered to enable patients to maintain oral hygiene in non-aesthetic areas.
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