Several factors seem to influence PSTD, including peri-implant soft tissue thickness, presence of <2 mm of keratinized mucosa, absence of facial bone wall, implant malposition, single-unit implants, attachment loss of adjacent teeth, and surgical trauma [21; 22; 23]. Different surgical procedures have been recommended to treat PSTD on the vestibular side, and the coronal advancement flap with or without vertical releasing incisions plus a connective tissue graft is the most commonly described technique in the literature [17; 24; 25]. Recently, [PERSON] et al. [26] in 2019, made a classification to describe PSTD on single implants in the esthetic zone, adding a subcategory in relation to the papilla dimension (Table 1). In addition, they recommend a decision-making protocol to select the most appropriate treatment. This classification identifies four classes of dehiscere (PSTD) according to the vestibular-palatal position of the implant-supported crown profile (except class I, which is characterized by a soft tissue margin located at the same level as the ideal position of the gingival margin of the natural tooth counterpart; thus, only an inadequate thickness of the peri-implant keratinized mucosa is identified). Three subcategories (for classes II, III and IV) are also identified according to the dimension of the interproximal papillae: (a) the tip of both papillae is >3 mm coronal to the ideal position of the soft tissue margin of the implant-supported crown; (b) the tip of at least one papilla is <3 mm coronal to the ideal position of the soft tissue margin; (c) the height of at least one papilla is at the same level or more apical to the ideal position of the soft tissue margin of the implant-supported crown. However, in the [PERSON] et al. [26] classification, minimally invasive approaches that do not involve such extensive flaps without the need for vertical releasing incisions are not included as a treatment option, whereas they should be in great demand by patients and clinicians. In addition, patients do not always accept implant removal as a treatment option in the presence of PSTD. Indexes have been developed to evaluate soft tissue esthetics in order to monitor mainly the appearance around implant-supported crowns in the anterior region. One of the first was [PERSON] et al. [27] in 2005, who proposed an index called the \"Pink Esthetic Score\" (PES) focusing mainly on the appearance of soft tissues around implant-supported crowns. In 2009, [PERSON] et al. [28] made a modification in the sense of assessing not only the peri-implant soft tissues but also the optical characteristics of the restoration, called the \"White Esthetic Score\" (WES). Their assessment is ordinal from 0 (poor esthetics), 1  
\begin{table}
\begin{tabular}{p{34.1 pt} p{142.3 pt} p{142.3 pt} p{142.3 pt}} \hline \hline \multirow{2}{*}{**Class**} & \multicolumn{1}{p{142.3 pt}}{**Peri-Implant Soft Tissue Dehiscence Characteristics**} & \multicolumn{1}{p{142.3 pt}}{**Subclass**} & \multicolumn{1}{p{142.3 pt}}{**Recommended Surgical Treatment**} \\ \hline I & The soft tissue margin is located at the same level of the ideal position of the gingival margin of the homologous natural tooth, and the color of the output of the judgment itself is visible only through the mucosa and/or there is a lack of keratinized tissue/soft tissue thickness. & \multicolumn{1}{p{142.3 pt}}{**Ia: coronally advanced flap (CAF) or tunnel plus CTG (or other graft substitutes). **} \\ II & The soft tissue margin is located at the same level of the ideal position of the imagin of the homologous natural tooth, and the implant-supported crown profile is located inside (more palatal) the imaginary curve line that connects the profile of the adjacent teeth at the level of the soft tissue margin. & \multicolumn{1}{p{142.3 pt}}{**Ia: No crown removal, CAF plus CTG. **} \\ III & The implant-supported crown profile is located outside (more palatatat) the imaginary curve line that connects the profile of the adjacent teeth at the level of the soft tissue margin.