The clinical significance and application of the peri-implant phenotype in dental implant surgery: a narrative review

Abstract

Background and objective: In recent years, the concept of the peri-implant phenotype has become a new standard for the clinical evaluation of the soft and hard tissues surrounding dental implants. Improving this phenotype enhances the likelihood of achieving long-term favorable results and is a necessary consideration during implant planning. Stable peri-implant tissue support is also crucial for the functional and aesthetic value of implant restoration. Herein, the authors review the clinical significance of the peri-implant phenotype and assess the timing of treatment strategies for improving peri-implant phenotype elements.

Methods: A literature search was performed to retrieve papers on peri-implant tissue management and clinical outcomes published up to November 24th, 2022 in PubMed, Web of Science, EMBASE, and Scopus.

Key content and findings: The optimal time to improve peri-implant bone thickness (PBT) is with augmentation procedures before implant surgery or at the same time as first-stage surgery. Similarly, issues associated with keratinized mucosa width (KMW) and mucosal thickness (MT) should be addressed before final restoration. The establishment of supracrestal tissue height (STH) depends on the MT and implant depth of the patient. Furthermore, special attention should be paid to the effect of the peri-implant phenotype on the prognosis of immediate implant placement in the aesthetic zone.

Conclusions: The long-term success of implant restoration depends on careful planning that considers appropriate interventions for improving the peri-implant phenotype at different stages of treatment to reduce iatrogenic variables.

Keywords: Peri-implant phenotype; implant restoration; surgical procedures; timing; tissue grafts.

Figure 1

The peri-implant phenotype. Created with https://biorender.com/. KMW, keratinized mucosa width; MT, mucosal thickness; STH, supracrestal tissue height; PBT, peri-implant bone thickness.

Figure 2

A typical case of soft tissue augmentation in a patient with severe soft and hard tissue deficiencies. (A,B) The KMW in the edentulous area is of less than 1 mm, and there are severe vertical and horizontal bone defects. (C) An apically repositioned flap procedure was performed at the recipient site. (D) A free gingival graft is harvested from the palate. (E) The free gingival graft is placed at the recipient site. (F) The graft is stabilized with sutures. (G) The sutures are removed after 14 days. (H) There is a significant increase in the keratinized mucosa and soft tissue volume after adequate healing. KMW, keratinized mucosa width.

Figure 3

A typical case of bone augmentation prior to implant placement. (A) Two bone blocks, harvested near the anterior nasal spine, are fixated with screws. (B) The bone graft material is placed on the labial side of the alveolar ridge. (C) The absorbable barrier membrane is positioned. (D) Tension-free closure of the surgical area is conducted. (E,F) Successful bone augmentation is achieved. (G) Implants and healing abutments are inserted. (H) Cone beam computed tomography confirms the presence of adequate bone volume on the labial side.

Figure 4

A case of bone augmentation conducted simultaneously with implant placement. (A) A dental implant is placed following the implant protocol, and part of the buccal implant surface is exposed due to bone dehiscence. (B) Bone grafting is performed to close the dehiscence. (C) A collagen membrane is applied. (D) Following the release of the flap by vertical incision, tension-free primary wound closure is achieved. (E) The buccal view after 6 months of healing. (F) Cone beam computed tomography confirms the presence of adequate bone volume on the labial side.

Figure 5

A case of soft tissue augmentation conducted simultaneously with implant placement. (A) The preoperative coronal view of the posterior mandible, with an insufficient KMW and soft tissue volume. (B,C) Implant placement with a surgical guide. (D) The split-thickness flap is positioned apically. (E,F) Free gingival graft harvesting on the palate. (G) The graft is immobilized with periosteal sutures. (H) A significant gain in the peri-implant KMW and MT is observed after 4 weeks of healing. KMW, keratinized mucosa width; MT, mucosal thickness.

Figure 6

Immediate implant placement with a CTG to increase buccal MT. (A) Preoperative clinical situation. (B) Atraumatic extraction of the left central incisor. (C) Implant placement. (D) A partial-thickness pouch is constructed. (E) A CTG is harvested on the palate using the L technique. (F) The CTG is positioned and sutured in the pouch. (G) The provisional restoration is placed. (H) The provisional restoration is adjusted to clear all occlusal contacts. CTG, connective tissue graft; MT, mucosal thickness.

Figure 7

Application of a custom healing abutment. (A) The preoperative buccal view of fractured central incisors. (B) Immediate implant placement without flap elevation. (C,D) Two custom healing abutments maintain the gingival architecture. (E,F) Following adequate healing, the final restorations are placed, and the contour of peri-implant soft tissue is maintained.

Figure 8

The use of a free gingival graft to increase the peri-implant KMW during second-stage surgery. (A) The preoperative evaluation shows a lack of keratinized tissue around the implant placed at site 25. (B) A split-thickness flap is positioned apically. (C) Free gingival graft harvesting on the edentulous alveolar mucosa. (D) The graft is transferred to the recipient site and sutured. (E) A healing abutment is inserted at the implant placed at the site 26. (F) The surgical area is sutured. (G,H) After delivery of the final restoration, an increase of 2–3 mm in the KMW is recorded at site 25. KMW, keratinized mucosa width.

Figure 9

Use of the roll flap technique to increase buccal MT during second-stage surgery. (A,B) Papilla-saving incisions and reflection of a palatal partial-thickness flap. (C) A pedicled connective graft is raised with a periosteal elevator. (D) The CTG is rolled to the buccal side of the implant by suturing. (E) Primary closure is obtained with a healing abutment in place. (F) The improved buccal soft tissue contour after healing. MT, mucosal thickness; CTG, connective tissue graft.

Figure 10

The use of a U-shaped incision to increase buccal MT during second-stage surgery. (A) The preoperative clinical situation. (B) A U-shaped incision was made above the implant site. (C) The keratinized epithelium is removed by scalpel. (D) The de-epithelialized CTG is rolled to the buccal side by suture. (E) A healing abutment is inserted. (F) Sufficient buccal MT is observed after healing. MT, mucosal thickness; CTG, connective tissue graft.

Figure 11

Free gingival grafting in post-restoration peri-implant mucositis. (A) Peri-implant mucositis is present, with bleeding on probing and an attached gingiva width <1 mm. (B) An apically repositioned flap procedure is performed in the recipient site. (C,D) Free gingival graft harvesting from the palate. (E) The graft is stabilized with sutures. (F) There is a significant increase in keratinized mucosa after adequate healing.