Peri‑Implant Soft‑Tissue Integration and Management. Mario Roccuzzo

      Fig 9k Clinical view six months after regeneration surgery. Optimal healing.

      Figs 9l Radiographic view of the augmented area before implant placement surgery.

      Fig 9m After removal of the Ti-mesh, two Straumann Tissue Level implants were placed at sites 35 and 36 (SP, RN, diameter 3.3 mm, length 8 mm, and SP, RN, diameter 4.1 mm, length 6 mm; Institut Straumann AG).

      Fig 9n Sutures applied for optimal non-submerged healing.

      Fig 9o Three months after surgery. Implants surrounded by a thick cuff of healthy keratinized mucosa. The impressions could now be taken for the final restoration.

      Fig 9p Six months after implant placement, the probe indicated a shallow sulcus with no signs of inflammation. Prosthetic procedures: Dr. Walter Gino – Torino, Italy

      Based on the conclusions of the 2017 World Workshop, namely that a significant amount of controlled prospective studies indicated that thin soft tissue around implants leads to increased marginal bone loss compared to thick soft tissue, clinicians may be encouraged to create ideal soft-tissue conditions before placing implants. Mucogingival surgery may be indicated particularly in patients with thin soft tissue and no keratinization. Each of the two steps of this approach is relatively easy to perform. However, the patient will have to accept the discomfort of two separate interventions not less than a month apart from each other.

      Even though recent publications provided guidelines for decision-making if the clinician considers autologous soft-tissue grafting to promote peri-implant health or preserve marginal bone levels at implant sites with insufficient soft-tissue dimensions (Thoma and coworkers 2018a; Giannobile and coworkers 2018), the ideal clinical solution should be individually determined and should represent the results of a proper patient-clinician discussion.

3.3 Soft-Tissue Management During Supportive Care

      Recent evidence has shown that favorable long-term implant survival rates can be achieved even in periodontally compromised patients, provided they are placed on an individually tailored supportive peri-implant/periodontal therapy (SPT) program, which includes continuous evaluation of the occurrence and the risk of disease progression (Roccuzzo and coworkers 2014a).

      It has been suggested that implant therapy today must not be limited to surgery/restoration, but should also include an SPT program tailored to the patient’s risk profile. Data indicate a minimum recall interval of five to six months (Monje and coworkers 2019). However, in terms of interventions to prevent peri-implant biologic complications, it is unclear at what point mucogingival surgery may be indicated to improve peri-implant soft-tissue conditions.

      According to the 2017 World Workshop (Caton and coworkers 2018), peri-implant mucositis is characterized by bleeding on probing and by visual signs of inflammation; there is robust evidence that it is caused by plaque. Peri-implantitis was defined as a plaque-associated pathological condition occurring in the tissue around dental implants, characterized by inflammation in the peri-implant mucosa and subsequent progressive loss of supporting bone. Peri-implant mucositis precedes peri-implantitis, but can be reversed with measures aimed at removing plaque.

      Based on these considerations, every effort should be made to motivate the patients and to facilitate their ability to maintain plaque control both at implants and teeth, aiming for a low full mouth plaque score. The 6th ITI Consensus Conference (Heitz-Mayfield and coworkers 2018a) recommended the provision of individualized supportive care according to the patient’s needs and risk profile. This should include performing oral hygiene, removing biofilm, monitoring oral health, and reducing modifiable risks.

      From this point of view, anatomical aspects must be considered in attempting to intercept those site-specific conditions that constitute a local risk factor for the development of peri-implantitis, such as deep peri-implant pockets, the presence of a frenulum, or the lack of keratinized attached mucosa. In these circumstances, SPT may also include a surgical modification of the soft tissue to facilitate plaque control, as demonstrated in recent studies.

      In a controlled clinical, immunological, and radiographic study, Büyüközdemir Aşkın and coworkers (2015) examined the necessity for peri-implant keratinized tissues for effective maintenance. Forty patients with inadequate keratinized tissue were assigned to two groups: free gingival grafting (FGG) was performed in one group, while the other group received standardized maintenance with no additional surgery. Clinical parameters, peri-implant sulcular fluid (PISF) volumes, PISF Interleukin-1β (IL-1β) concentrations, and bone loss were analyzed. Significant improvements in clinical and immunological parameters were noted only for the FGG group throughout the study period. The authors concluded that FGG performed around implants lacking keratinized tissue is a reliable method, leading to significantly improved clinical and inflammatory parameters.

      Oh and coworkers (2017) evaluated clinical and radiographic outcomes following a free gingival graft around implants with limited keratinized mucosa, compared to oral prophylaxis alone. Their prospective study investigated 41 implants with a lack of keratinized mucosa in 28 subjects: 14 patients received an FGG followed by prophylaxis and 14 subjects received oral prophylaxis alone. The results of the study indicated that the gingival index (GI) and crestal bone loss was significantly lower in the FGG group than in the control group. The authors concluded that a free gingival graft for implants exhibiting a lack of keratinized mucosa is a valid treatment option that reduces mucosal inflammation and maintains crestal bone levels in the short term.

      These preliminary results seem to confirm the beneficial role of keratinized tissue for maintaining healthy conditions around implants. Peri-implant mucogingival surgery may therefore be considered an essential part of SPT in specific circumstances.

      The contribution of a frenulum to the etiology of a soft-tissue dehiscence around natural teeth remains controversial. Cortellini and Bissada (2018) reported it to be (although at low levels of evidence) one of the conditions that might contribute to the development of gingival recession, as a frenulum may compromise the efficacy of oral hygiene.

      Nothing was mentioned during the 2017 World Workshop regarding the possible negative impact of a frenulum attached to an implant.

      Nevertheless, from a clinical point of view, treatment may be indicated in cases where a marked frenulum attaches to thin peri-implant mucosa and there is a risk of development of progressive recession. Moreover, due to the lack of a tight soft-tissue seal, optimal plaque control may be more difficult to achieve. Finally, in some circumstances, these situations lead patients to report brushing discomfort. Figures 10a-f show an example of soft-tissue grafting performed during SPT to facilitate proper plaque control in an area with a frenulum, lack of keratinized mucosa, and a shallow vestibulum.

      Fig 10a-b Radiographic and clinical view of two implants (SLA S, diameter 4.1 mm, length 12 mm, and S, diameter 4.1 mm, length 10 mm; Institut Straumann AG), placed two years previously into a thin ridge, presenting with an inferiorly attaching frenulum facially to implant 26. Treatment was indicated to facilitate plaque control and to prevent further progression of the recession.