Microleakage of bulk fill polymer-based composite: review of the literature

Currently, the most widely used dental restoration materials in the field of dental aesthetics are polymer-based composite; therefore, the offer within the market is increasing with a focus on aesthetic, mechanical, and process improvement needs. Bulk fill or block filling polymer-based composite has been widely accepted, they have an advantage because they can be placed in blocks of up to 4 to 5 mm1 reducing clinical times in contrast to traditional polymer-based composite. Therefore, within the present study, we have focused on investigating the microleakage of this type of polymer-based composite and what are the main reasons for it. Objectives: A literature review on the evaluation of the degree of microleakage of bulk fills polymer-based composites. Methodology: An electronic literature search was performed on bibliographic bases such as PubMed, Scielo, Science Direct, Cochrane, and Wiley Online using the keywords: “marginal adaptation”, “bulk fill resin”, “bulk fill composite”, and “microleakage”. Conclusions: Block filling polymer-based composite tends to have the same amount of microleakage as conventional polymer-based composite. Adhesive systems are essential to greatly reduce the formation of gaps between dental materials and dental structures. Class II cavities will always be better to treat the proximal face first and then manage as a class I to reduce marginal microleakage. The fluid block filling polymer-based composite used as a base greatly helps the adaptation of the polymer-based composite and decreases marginal microleakage.