Statement of problem: the bond strength between adhesive cement and root dentin can be affected by irrigation protocols. Purpose: therefore, the objective of this systematic review was to answer the following question: Do irrigation solutions used during root canal instrumentation influence the adhesion of glass fiber posts to root dentin? Material and Methods: this study followed the recommendations of PRISMA 2020 for writing. PubMed, Scopus, Web of Science, and LILACS databases were searched for articles published until 26 January, 2022. Grey literature and a manual search were also performed. The inclusion criteria were based on the PICO strategy: permanent human or animal teeth (P), which were irrigated during root canal instrumentation with endodontic substances (I) and compared to irrigation with sodium hypochlorite at various concentrations (C) to analyze the bond strength of glass fiber posts (O). Two authors independently performed data extraction and the risk of bias. Results: eight articles were included. Four articles were classified as having a high risk of bias, where the others as medium risk. Studies have reported conflicting results regarding the influence of irrigating solutions and the different concentrations of sodium hypochlorite on the adhesion of glass fiber posts to root dentin. Conclusion: the heterogeneity between studies did not allow the conclusion of a true estimate regarding this topic, and further well-designed studies are needed to clarify this issue. Register: CRD42020221835.

Infiltração dentária; Cimentos de ionômero de vidro; Dentes decíduos. Dental leakage; Glass ionomer cements; Primary teeth. Marginal Microleakage in Class II Cavities Restored with Conventional and Resin-Modified Glass Ionomer Cements: a Comparative Study Objective: To evaluate the level of microleakage in class II cavities prepared in human primary molars restored with 2 conventional (Maxxion R and Vidrion R) and 2 resin-modified (Vitremer and Vitro Fill LC) glass ionomer cements. Method: Nineteen human primary molars were chosen from a tooth bank. Class II cavities with standardized dimensions were prepared with cylindrical diamond burs on the mesial and distal surfaces of each tooth. The cavities were then restored with 2 conventional glass ionomer cements [Maxxion R (G1) and Vidrion R (G2)] and 2 resin-modified glass ionomer cements [Vitremer (G3) and Vitro Fill LC (G4)]. The restored teeth were coated with 2 layers of nail polish (Colorama ®) and, after drying of the polish, the teeth were immersed in a 50% silver nitrate solution for 24 hours. Next, all teeth were cut longitudinally through the restoration center and examined with a stereomicroscope and the microleakage was evaluated by qualitative criteria based on the attribution of scores. Results: All materials presented varied microleakage levels, but Vitremer (G3) presented the best results. No statistically significant differences were observed among Maxxion R (G1), Vidrion R (G2) and Vitro Fill LC (G4). Conclusion: None of the tested glass ionomer cements was capable to completely prevent microleakage occurrence, but Vitremer presented the lowest microleakage scores, while the Maxxion R, Vidrion R and Vitro Fill LC did not differ significantly from each other.

RESUMO DESCRIPTORS DESCRITORESCárie dentária; Dentina; Microscopia eletrônica de varredura.Dental caries; Dentine; Scanning electron microscopy.