## 1 Introduction  
The complete aesthetic and functional rehabilitation of partial edentulousness is challenging, especially when it is dependent on single implant treatment. Restoring a missing tooth with an implant-supported prosthesis could be the optimal treatment choice; however, it requires good clinical planning and the sophisticated management of hard and soft tissues. Contemporary implant dentistry is constantly searching for solutions to improve biological and surgical outcomes [1].  
The choice of an appropriate implant suprastructure, which should be made according to the individual characteristics of each patient, is a leading factor in achieving good aesthetic results [2]. Despite the availability of standardized prosthetic components, treatments often cannot meet the individual needs and personal requirements of each patient and cannot provide the most favorable position for future restoration and gingival architetonics [3,4]. However, individualized (custom) abutments can prevent many of the complications observed in prosthetic treatments using factory-manufactured abutments in cases in which there are anatomical limitations, such as lack of sufficient distance from the antagonist, large interproximal space, unparallel implant position, etc. [5]. New materials and production technologies allow for fast and accurate manufacturing [6, 7, 8]. Custom-made CAD/CAM abutments have a better survival rate compared to conventional suprastructures, but there are still only a few clinical trials that have been described in the literature.  
Because of this, there is a lack of studies considering individualized CAD/CAM-milled abutments. Most of the existing studies did not include control groups or make comparisons with conventional implant abutments. The most commonly reported clinical outcomes that were measured are soft tissue volume and health, marginal bone level, aesthetic score, and success rate. These studies also demonstrated substantial heterogeneity regarding the manufacturing systems and materials of the abutments examined, the specific clinical outcomes observed, the design of the studies, and the measurement techniques employed. Studies represent a follow-up period of 1-3 years. For studies comparing CAD/CAM abutments with conventional abutments, no significant differences have been observed in most of the clinical outcomes at the 1-year follow-up [9].  
There are no available studies that consider the pre-milled abutment titanium blanks included in the present research. These blanks are prefabricated with genuine connections to ensure accurate fit and superior performance with the implant connection.  
Definite guidance regarding the use of different types of abutments over implant superstructures that considers their specific morphological and biomechanical characteristics, especially in the critical transmucosal area, is needed. These statements indicate the need to formulate recommendations for the optimal application of different implant superstructures according to their biomechanical and clinical behavior.  
The working hypothesis of the present research was that the pre-milled abutment titanium blanks with genuine connections in combination with the ceramic material of the crown would have an advantage over the prefabricated Ti-base abutments and zirconium crowns due to the possibility of individual varieties of transmucosal profiles based on functional, biological, and aesthetic indicators, supporting their long-term clinical use.