Articles - Forum Implantologicum

Article

Feature Article

May 14, 2020 // 14 min read

The Importance of Keratinized Peri-Implant Mucosa for Effective Long-Term Maintenance Care

DOI: 10.3290/iti.fi.45641

Abstract

For several years, the need for keratinized mucosa (KM) to reduce the risk of peri-implant biological complications has been a controversial topic. Recently, several studies and systematic reviews have confirmed that adequate KM may favorably impact peri-implant health and stability in the long-term. This article will review the recent literature on this topic and suggest clinical guidelines for when to increase peri-implant KM to facilitate surgical handling and enhance long-term maintenance. In conclusion, clinicians should keep in mind that a free gingival graft to increase the width of KM before implant placement may be indicated in situations where the soft tissue is so thin that its manipulation could be particularly difficult, as well as when an implant is already present, but patient reports soreness during oral hygiene procedures.

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Introduction

It is well established that excellent outcomes in terms of long-term implant survival rate can be obtained in patients placed on an individualized supportive care program, including professional and self‐performed biofilm removal at implants and teeth (Heitz‐Mayfield et al. 2018). The width of keratinized soft tissue (KT) around implants may vary between zero and several millimeters and the presence of KT may facilitate sufficient plaque control. Even though it has been proposed that a circumferential sealing effect is mandatory for long-term success, in particular in the presence of peri-implantitis infections (Warrer et al. 1995), the controversy about the importance of KT around dental implants started in the late 90s, and has produced much academic debate.

Fig. 1: An 81-year-old female patient, previously treated with two implants supporting an overdenture, presented with swelling, bleeding, and pain in the facial aspect of the left implant, in an area with no keratinized tissue. The implant shoulder is below the mucosal surface, i.e. with the mucosa growing over the implant. Such a situation typically evolves spontaneously into significant inflammation with the loss of KM and peri-implant bone due to plaque accumulation and consequent edema.

Fig. 2: An 83-year-old-female patient was visited 20 years after placement of two implants supporting an overdenture. Even though plaque control was not perfect, the implants are surrounded by a keratinized soft-tissue seal with no signs of inflammation

Fig. 3a: A 52-year old female, presenting an old mesial cantilever on the second molar, was seeking for placement of tooth 46

Fig. 3b: After removal of the prosthesis, the complete lack of attached mucosa associated with the presence of a frenum was evident in the edentulous area

Fig. 3c: A free gingival graft, harvested from the tuberosity, was sutured to the periosteum left in situ after the elevation of a split thickness flap

Fig. 3d: Clinical situation 3 months after mucogingival surgery

Fig. 3e: Buccal view of the implant placed

Fig. 3f: Non-submerged healing of the FGG sutured with 4-0 Vicryl™

Fig. 3g: Clinical situation 2 years after delivery of definitive crown

Fig. 3h: Radiographic image, taken at the 3-year follow-up, showing ideal interproximal bone levels

Fig. 4a: A 44-year old female, presenting bone atrophy in the posterior left mandible, was seeking implant placement in Fall 2007. Radiograph after bone blocks were fixed to the mandible

Fig. 4b: Bone anatomy upon surgical re-entry after 5 months, for the placement of a Wide Neck Implant (WNI)

Fig. 4c: Occlusal view, at the cementation of the definitive crown, 3 months after implant placement

Fig. 4d: Clinical situation 6 months after delivery of the ceramic crown

Fig. 4e: Radiographic image, taken in December 2010, showing a minimal interproximal bone loss

Fig. 4f: Clinical situation 4 years after delivery of the definitive crown. During a maintenance appointment, peri-implant soft tissue recession associated to brushing discomfort was noticed

Fig. 4g: A free gingival graft (FGG) was proposed and accepted by the patient to improve the peri-implant soft tissues

Fig. 4h: The FGG, harvested from the palate, was trimmed for ideal adaptation

Fig. 4i: The FGG was sutured on a split thickness flap by means of 4-0 Vicryl™ around the smooth collar of the implant

Fig. 4j: Probing at the buccal site in December 2014, showing the absence of inflammation and/or bleeding

Fig. 4k: Buccal view at the 10-year follow-up, demonstrating the stability of the soft tissue margin

Fig. 4l: Radiographic image, taken at the 10-year follow-up, revealed the improvement of the interproximal bone levels

Table 1: Clinical situations where patients with implants presenting one or more of the following conditions may benefit from a free gingival graft for effective peri-implant maintenance care.