## 3 Results and Discussion
### Initially Proposed Protocols (2014-2015)
#### 3.4.3 Design of Prosthetic Crowns and Soft Tissue Compression  
The convergent neck profile introduces innovative concepts in implant prosthetic protocols for crown preparation. The presence of a smoother transition due to the absence of a proper finishing line between the crown and the implant can promote better oral hygiene and overall patient outcomes (see Figure 4). In contrast, other configurations (such  
Figure 3: Minimally invasive protocol performed in 2014–2015. (**a**) Clinical view of convergent neck implant placed with a flapless technique immediately after flapless surgeries, (**b**) after 3 months, (**c**) after definitive crown cementation, and (**d**) after 10-year follow-up. Soft tissue stability and optimal results were observed.  
as Platform Switch necks) involve the crown preparation ending above the implant level, resulting in a prosthetic step or ledge at the implant-abutment connection.  
It is also possible to more freely design the crown margin at the implant neck, in particular when a transmucosal/exposed protocol is performed. The provisional crown could guide soft tissue healing, enabling the formation of thick and non-inflamed tissue [8, 17] (Figures 2 and 3). In this situation, after at least one month of stabilization, impressions of the soft tissues were taken around the new emergence profile formed by the temporary restorations, and the definitive restorations were fabricated according to a defined laboratory protocol. Creating a new emergence profile with the restoration helps the soft tissue to adapt, increasing its thickness and stabilizing the gingival margin.  
The BOPT concepts have been applied to Prama implant-supported restorations, featuring a convergent transmucosal neck that extends to the abutments without a distinct finishing line. This approach aligns with a published guideline for managing implant restorations, which recommends a subcritical contour that is as convergent (concave) as possible [58].  
The important concept is mainly that the convergent transmucosal neck creates space for the soft tissues and provides a regenerative space that leads to a stable coagulum, which potentially will turn into soft tissue, increasing the peri-implant tissue thickness. This is one of the reasons to obtain different neck heights, recently available in the market (Prama Short neck or Long neck).  
The design of the crown, specifically the soft tissue margin, follows the contour of the gum tissue without forming a gingival tunnel. The connective fibers ensure a perfect seal around the convergent neck, as demonstrated by some histological studies [6], and they are not altered by the presence of intramucosal abutments. Indeed, the convergent  
Figure 4: Clinical case performed in 2015–2016. (**a**) Post-extractive insertion of a Prama implant (#25) and (**b**) delayed insertion of a Premium SP implant (#26). Both implants were placed submerged with no exposition of the neck. A cover screw was placed on the Prama implant, while a healing screw was immediately placed on the Premium SP implant to avoid second surgeries during the subsequent prosthetic phases. (**c**) Periapical X-rays at 1-year follow-up bone stability around Prama implant and slight cervical bone loss around Premium implant. (**d**) The MBL was stable at the 8-year follow-up.  
neck associated with the UTM micromorphology demonstrated faster fibroblast adhesion and proliferation when compared to divergent neck implants with the standard (smooth) micromorphology, as demonstrated in a recent histopathological human study [59].