Dentin Microhardness and Sealer Bond Strength to Root Dentin are Affected by Using Bioactive Glasses as Intracanal Medication

Abstract

This study investigated the human dentin microhardness (MH) and the MTA Fillapex® (Fillapex) and AH Plus®(AH) bond strength (BS) to dentin after using calcium hydroxide (Ca(OH)2) and bioactive glasses (45S5 and an experimental niobium phosphate bioactive glass (NbG)) as intracanal medications. For the MH test dentin slices were filled with medications and were submitted to Knoop MH (KHN) test (at day-0 (baseline data/without medication) and at day-15 (after using medication)). For the BS test, after medications had remained for 15 days in the roots, dentin slices were obtained and filled with the sealers. Seven days later, sealer BS to dentin was measured by push-out test (MPa). Data were statistically analyzed. Failure mode was visually assessed. The use of NbG, 45S5 for 15 days, increased the dentin MH and reduced the BS between AH sealer and dentin, but did not interfere with the Fillapex BS.

New and Efficient Bioactive Glass Compositions for Controlling Endodontic Pathogens

“…Moreover, in vitro studies demonstrated that the use of Ca(OH) 2 as a long-term intracanal medication reduces the microhardness of the dentin and consequently the resistance of the tooth to fractures. Clinically, 32-40% of root fractures are associated with the use of Ca(OH) 2 in treatment [20,21]. It has also been proven that the remaining particles (which are not completely removed during chemomechanical instrumentation and disinfection) affect the sealant's bond with the dentin, which increases the probability of treatment failure [20,22].…”

“…Clinically, 32-40% of root fractures are associated with the use of Ca(OH) 2 in treatment [20,21]. It has also been proven that the remaining particles (which are not completely removed during chemomechanical instrumentation and disinfection) affect the sealant's bond with the dentin, which increases the probability of treatment failure [20,22].…”

“…To overcome the drawbacks related to the use of Ca(OH) 2 as intracanal medicament, new materials such as bioactive glasses (BGs) have been investigated. A good alternative to Ca(OH) 2 should promote dentin remineralization and bone regeneration by the formation of a hydroxyapatite layer [20]. Similar to Ca(OH) 2 , which is used in powder form for endodontic applications, BGs also need a vehicle (such as distilled water or saline solution) that facilitates accurate placement using a syringe.…”

“…BGs have been demonstrating their ability to stimulate osteocunduction, osteoinduction, and biocompatibility in in vivo and ex vivo studies [24]. Extremely relevant in root canal treatment, BGs may have combined antimicrobial properties, usually associated with the release of certain ions and alkalinization of the medium [20]. In addition to their osteo-regenerative effects, antiseptic activity has been reported for many promising BGs, including BGs doped with Zn-, Cu-, and Sr-ions [26][27][28].…”

Advances in Dental Materials “at a Glance.”

“…This arrangement allows for a myriad of possible therapeutic applications [ 6 ]. Grazziotin-Soares et al [ 7 ] using an experimental niobium phosphate bioactive glass, as intracanal medication, for 15 days, demonstrate an increase of the dentin microhardness contrary to the calcium hydroxide, which produces a weakening effect in dentin.…”