Depth of cure of bulk-fill and flowable resin in contact with mineral trioxide aggregate plugs in ex vivo immature teeth

Abstract

Introducción: Tooth development may be interrupted when the pulp becomes necrotic because of caries, trauma, or anatomical alterations such as dens evaginatus.Objective: To determine the depth of cure and hardness of an injected bulk-fill resin (Sonic Fill™) compared with a flowable resin (Revolution™) in teeth with incomplete apex formation.Material and Methods: Forty recently extracted uniradicular teeth were assigned for the study; 3 mm of the apex was cut to standardize all teeth to 13 mm, then the root canals were instrumented to a size 1.10 mm by using Peeso drills. A 3-mm mineral trioxide aggregate (MTA) plug was placed in the apical third. After etching the root canal walls, an intracanal adhesive system was placed and cured. Then, Sonic Fill™ was injected into the remainder of the root canal of 20 specimens randomly selected and a flowable composite resin (Revolution™) was placed in the others. All specimens were placed in a rectangular, acrylic base and sectioned along the long axis of the tooth. The depth of cure and hardness of the composite resin were evaluated using the Vickers micro-hardness test and compared with Student T test for independent groups.Result: Specimens in the SF group showed significantly (p = 1.6 × 10−6) higher Vickers micro-hardness (24.03±4.09 Kp) I.C.95% [20.88- 27.19] than those in the Revolution™ composite group (11.28±3.19 Kp) I.C.95% [8.82- 13.72].Conclusions: Specimens in the SonicFill™ group showed significantly higher Vickers microhardness than those in the flow able resin group, making the former more suitable for strengthening teeth with immature apexes.