INTRODUCTION: Recently, it was shown that the biomineralization process promoted by the interaction of mineral trioxide aggregate (MTA) with dentin in phosphate-buffered saline (PBS) positively influenced the push-out bond strength of the cement. This study investigated if the use of a PBS intracanal dressing promotes the biomineralization process of MTA apical plugs using an ex vivo apexification model. METHODS: White MTA was introduced into single-rooted teeth with standardized artificially created open apices to form 5-mm-thick apical plugs. The specimens were randomly divided into the following three groups of 10 samples each: group 1: the remaining canal space was filled with PBS as an intracanal dressing; group 2: the root segments were introduced in plastic vials containing floral foams with 20 mL of PBS; and group 3: the root segments were placed in the floral foams with 20 mL of PBS and a PBS intracanal dressing was used. After 2 months, the samples were processed for scanning electron microscopic observations. Data were analyzed by using the Kruskall-Wallis test. RESULTS: In group 1, the formation of an interfacial layer (IL) with intratubular mineralization (ITM) was more evident at the cervical third; however, no mineralization was revealed at the apical third. In group 2, there was no IL and/or ITM formation at the cervical third, but samples denoted IL and ITM formation at the apical third. Group 3 displayed the formation of IL and ITM at the different levels. CONCLUSION: It was concluded that the use of a PBS intracanal dressing promotes the biomineralization process at the inner side of MTA apical plugs.
INTRODUCTION: Recently, it was shown that the biomineralization process promoted by the interaction of mineral trioxide aggregate (MTA) with dentin in phosphate-buffered saline (PBS) positively influenced the push-out bond strength of the cement. This study investigated if the use of a PBS intracanal dressing promotes the biomineralization process of MTA apical plugs using an ex vivo apexification model. METHODS: White MTA was introduced into single-rooted teeth with standardized artificially created open apices to form 5-mm-thick apical plugs. The specimens were randomly divided into the following three groups of 10 samples each: group 1: the remaining canal space was filled with PBS as an intracanal dressing; group 2: the root segments were introduced in plastic vials containing floral foams with 20 mL of PBS; and group 3: the root segments were placed in the floral foams with 20 mL of PBS and a PBS intracanal dressing was used. After 2 months, the samples were processed for scanning electron microscopic observations. Data were analyzed by using the Kruskall-Wallis test. RESULTS: In group 1, the formation of an interfacial layer (IL) with intratubular mineralization (ITM) was more evident at the cervical third; however, no mineralization was revealed at the apical third. In group 2, there was no IL and/or ITM formation at the cervical third, but samples denoted IL and ITM formation at the apical third. Group 3 displayed the formation of IL and ITM at the different levels. CONCLUSION: It was concluded that the use of a PBS intracanal dressing promotes the biomineralization process at the inner side of MTA apical plugs.