Effectiveness of internal connections compared with external connections for the treatment of single, partial, or total dental implants rehabilitation: Overview of reviews

Aim: Dental implants have been shown to be a safe alternative for the replacement of missing teeth since they present few complications. These are related, among other elements, to the type of connection with which the abutments and attachments are joined to the implant. For this reason, in this study we performed an overview of systematic reviews with FRISBEE methodology on the use of internal connections compared to external connections of dental implants for the treatment of single, partial, or total rehabilitation. Materials and Methods: We performed a systematic search in the Epistemonikos database. We extracted data from the included systematic reviews, reanalyzed data of primary studies, and generated a summary of findings table. We used RevMan 5.3 and GRADEpro for data analysis and data presentation. Eleven systematic reviews were included after full-text screening, which had thirty-three clinical trials. Results: The outcomes were analyzed: mechanical complication (RR: 0.64), biological complications (RR: 1.01), survival (RR: 0.99), and mean marginal bone loss (MD: 0.3 mm lower). Conclusion: The use of internal connections in dental implants could lead to less marginal bone loss and fewer mechanical complications than implants with external connections, however, the confidence in the effect is limited due to a low certainty of evidence for both outcomes. Additionally, results show that different implant connections do not have an impact on dental implant survival and biological complication rates, with a moderate and low certainty of evidence, respectively.