Purpose: To evaluate the predictability of early and immediate loading protocols of implants in the posterior mandible and to investigate whether there is a difference in success rates, survival rates, and peri-implant parameters, including marginal bone level changes, between loading protocols. Materials and Methods: A comprehensive systematic review of the literature was conducted. The selection of publications reporting on human clinical studies was based on predetermined inclusion criteria and was agreed upon by two reviewers. Results: A total of 19 papers were selected: 8 on early loading, 9 addressing immediate loading, and 2 comparing immediate and early loading. Of the 19 studies, 5 were randomized clinical trials and 14 were prospective studies. Conclusions: Existing literature supports the early loading of microroughened dental implants in the partially edentulous posterior mandible at 6 to 8 weeks in the absence of modifying factors. Therefore, loading within this time frame can be considered routine for the majority of clinical situations in the posterior mandible, either with single crowns or fixed dental prostheses. Immediate loading of microroughened dental implants in the partially edentulous posterior mandible proved to be a viable treatment alternative. Caution is necessary when interpreting published outcomes for immediate loading, as the inclusion exclusion criteria are inconsistent and many subjective confounding factors are evident. Additional studies with longer follow-ups, specifically randomized clinical trials, are needed to consolidate the data for immediate loading. Priority should be given to trials testing immediate loading. Palabras clave: dental implants, fixed dental prostheses, loading protocol, partial edentulism, posterior mandible, single crown, systematic review