# Peri-Inplant Tissue Stability: A Series of Five Case Reports on an Innovative Implant Design
## 4 Discussion  
As per our understanding, this case series study marked the initial attempt to investigate the potential radiographic marginal bone level (MBL) exhibited by Collo implants positioned in the maxilla and mandible, specifically in pristine bone settings following functional loading. Notably, the crestal bone alterations observed from implant placement to the 12-month post-loading period comfortably met the success benchmarks outlined by [PERSON] et al. [16]. It is noteworthy that the primary occurrence of the MBL was noted at the 6-month follow-up compared to the 12-month evaluation, with the criterion set at a bone loss of less than 2 mm within the first year [16]. This was consistent with the scientific literature showing that most contour changes around implants occur in the initial phase after the placement of definitive reconstructions and remain stable thereafter [17; 18]. The mean MBL values measured in our study at 6 months were within the parameters reported by other authors, who proposed an MBL value of 0.5 mm as a distinct and objective criterion of success after loading within a 6-month follow-up period [19]. On the other hand, at observation times \(\geq\) 12 months, follow-up reports for the MBL described in the literature varied greatly. [PERSON] et al. reported MBL values of 1.11 \(\pm\) 0.4 mm (1 year), 1.26 \(\pm\) 0.42 mm (2 years), and 1.40 \(\pm\) 0.41 mm (3 years), representing a significant (\(p<\) 0.001) continuing time-dependent annual reduction [20]. [PERSON] et al., evaluating full-arch prostheses with the All-on-Four method in the mandible, reported average marginal bone losses of 1.72 mm and 2.32 mm at 10 and 15 years, respectively [21]. However, none of the 25 implants analyzed in the present study had a value exceeding an MBL of 3 mm, which, according to [PERSON] et al. [22], if we use the radiographic parameters recommended by the 2017 definition of peri-implant diseases, could be classified as diseased if accompanied by clinical parameters. The main goal of showing these cases results was to assess the effectiveness of Collo dental implants under immediate and delayed loading procedures through propensity across various factors like the time of evaluation, gender, and the implant placement arch. These findings align with similar results presented by [PERSON] et al. [23], indicating that factors such as age, gender, insertion torque, implant surface area, location, position, bone quality, and insertion torque did not impact peri-implant bone loss in short-splinted dental implants after a year of loading. The success outcomes observed in this study either supported or challenged the hypothesis linked to this innovative Nobel implant design. [PERSON] and [PERSON] [24] highlight the critical role of mucosal thickness in the formation of supracrestal tissue attachments around dental implants. Their findings indicate that insufficient mucosal thickness can lead to crestal bone resorption as the body strives to create adequate space for the connective tissue and junctional epithelium. This underlines the necessity for proper soft tissue management in implantology to ensure long-term success and stability around dental implants [24]. The structure of the connective tissue surrounding implants is crucial to prevent epithelial downward growth and provide mechanical protection to the osseointegrated part of the implant. Of the five cases presented in this study, in only one of them (Case #2), the KM value measured was 2 mm on average for times T1 and T2 while, in the other cases, the overall average obtained was 3.85 mm at both evaluation times (T1 and T2). These values were above the KM value of 2 mm described by other authors as the minimum quantity essential to minimize the incidence of peri-implant mucositis and future marginal bone loss [4; 25]. These results were in line with the results seen in the clinical studies of [PERSON] et al., where the stability of the peri-implant tissues was seen in the modification of the implant diameter [26; 27; 28].