Peri-Implant Bone Stability Around Tapered Implant Prosthetic Connection: A Systematic Review and Meta-Analysis Comparing Different Cone Morse and Conometric Implants Angle Contact and Coupling Interface Designs

Background/Objectives: Internal implant–abutment connection has been proposed to increase interface stability and reduce biological and prosthetic issues. The aim of the present investigation was to evaluate the influence of the implant abutment conical angle on marginal bone loss and mechanical complications. Methods: The literature screening was performed by considering Pubmed/MEDLINE, EMBASE, and Google Scholar sources. The eligibility process was conducted in order to perform a descriptive synthesis, determine the risk of bias, and carry out network meta-analyses. The following categories were considered for pairwise comparisons: external hexagon (EI), internal hexagon (HI), cone morse (CM) (<8° contact angle), and conometric joint (>8° contact angle). For the descriptive data synthesis, the following parameters were considered: sample size, implant manufacturer, prosthetic joint type, prosthetic complications, marginal bone loss, and study outcomes. Results: A total of 4457 articles were screened, reducing the output to the 133 studies included in the descriptive synthesis, while 12 articles were included in the statistical analysis. No significant differences in marginal bone loss were reported when comparing a cone angle of <8° and a cone angle of >8; Conclusions: Within the limits of the present investigation, the cone interface seems to produce lower marginal bone loss compared to external and internal hexagon connection. No differences were found when comparing a cone angle of <8° and a cone angle of >8°.