The apically positioned flap is a commonly used surgical approach, and is important for maintaining an adequate zone of keratinized tissue. With regards to implants, many studies suggest that the presence of healthy peri-implant soft-tissue plays an important role in long-term success of dental implants (see studies below). The video below provides a short summary of the apically repositioned flap. When you have enough attached gingiva a simple exposure or a punch will be fine. However, in many cases this is not possible, and an APF is indicated.
Block and Kent had reported that the presence of keratinized tissue was significantly associated with good mucosal health and crestal bone loss of 2 mm or greater was seen in areas with lack of KG. Warrer et al., in their animal experimental study in monkeys concluded that implants without keratinized mucosa resulted in more recession and attachment loss when compared with implants with adequate keratinized tissue. Chung et al., suggested that plaque accumulation and gingival inflammation were higher around dental implants with keratinized mucosa <2 mm. Recent studies by Bouri et al., Kim et al., Schrott et al., reported that increased width of keratinized mucosa around dental implants is associated with lesser soft-tissue recession and greater hard tissue stability resulting in an advantage for long-term maintenance of implants.[3,4,5]
1. Warrer K, Buser D, Lang NP, Karring T. Plaque-induced peri-implantitis in the presence or absence of keratinized mucosa. An experimental study in monkeys. Clin Oral Implants Res. 1995;6:131–8. [PubMed]