Clinical Evaluation of Soft Tissue Esthetics Around Immediate Implant Using Dual Zone Therapeutic Concept Versus Buccal Gap Fill to Bone Level

Immediate implant placement in the esthetic zone is very challenging procedure although it is documented as a promising procedure (Berglundh, Persson and Klinge, 2002)(Cosyn et al., 2011). Extraction is usually accompanied by remodeling of the hard tissues which is more crucial in the anterior maxilla as it affects soft tissue esthetics(Araujo and Lindhe, 2005)(Covani et al., 2004)(Juodzbalys and Wang, 2007). It is well established that implant placement without filling the buccal gap leads to noticeable amount of bone loss at the alveolar contour(Botticelli, Berglundh and Lindhe, 2004)(Sanz et al., 2010). The protocol of immediate implant and temporization serves to provide acceptable esthetic results but soft tissue stability around the implant restoration is not always satisfactory(Noelken et al., 2018).Amount of soft tissue recession can be specified following immediate implant placement, even with flapless technique there is a limited risk of midfacial recession(Cosyn, Hooghe and De Bruyn, 2012).It was found that inadequate bone grafting in the facial defect increases the chance of mid facial recession(Le, Borzabadi-Farahani and Pluemsakunthai, 2014).

By definition, the dual zone can be divided into soft tissue zone and bone zone; the soft tissue zone is the vertical dimension change measured from the free gingival margin to the mid crest labially, the bone zone is the hard tissues measured from the crestal bone towards the apex(Chu et al., 2012). The concept of the dual zone aims to maintain the hard, soft tissue volume and the blood clot where the grafting material act as a scaffold containing them and this will enhance the initial healing compared to the classic protocol of bone filling till the buccal bone level(Chu et al., 2012). A recent study claims that the xenograft particles can be successfully incorporated within the soft tissue without inflammation enhancing the soft tissue profile(Araujo and Lindhe, 2005). The temporary restoration has shown socket sealing property which protect and contain the blood clot and the graft material enhancing healing,thus filling the gap without involvement of the soft tissue has been the rational for immediate implant placement(Trimpou G, Weigl P, Krebs M, 2010).The main benefit of the dual zone concept is maintaining the blood supply from the periosteum and endosteum producing maximum healing potential with preserving the soft tissue stability by filling the soft tissue zone with bone graft in addition to immediate temporization acting as socket seal(Chu et al., 2012).