The use of internal irrigation versus external and combined irrigation during dental implant bed preparation, a systematic review

PURPOSE: The aim of this study was to analyze the role and capacity of internal irrigation compared to external irrigation and, when applicable, combined irrigation to reduce and control bone heating during implant bed preparation. METHODS: This systematic review was conducted according to predefined inclusion and exclusion criteria. A comprehensive literature search was performed in PubMed, Embase, Cochrane, Web of Science, and Google Scholar up to September 2025. Studies evaluating irrigation methods during implant osteotomy were included. Screening, selection, and risk of bias assessment were performed following a standardized protocol. RESULTS: 201 records were found. After deduplication, screening, and full-text evaluation, 10 in vitro studies were included for qualitative analysis and evaluation of risk of bias. At the same time, no animal studies fully met the inclusion criteria, and no randomized clinical trials were identified. Reports show that the peak temperature changes (ΔT) varied substantially, from 1.48 to 75.4 °C. CONCLUSION: In most studies, internal irrigation was shown to have superior cooling efficiency during the implant bed preparation compared to external irrigation, particularly in deeper osteotomies or when surgical guides were used. Combined irrigation also appeared to be a beneficial method. However, its performance varied depending on drill design and experimental setup. Risk of bias, assessed with the QUIN tool, was moderate to high, reflecting heterogeneity in study model, sampling, and reporting. Within the limitations of current evidence, internal irrigation emerges as an efficient method to control thermal and heat elevation during implant osteotomy.