Compressive Deflection of Composite Layered on Biodentine and Two Bases

R. Yapp (1), H. Strassler (2), C. Bracho-Troconis (3), G. Richard (4), and J. Powers (1), 1 Dental Consultants, Inc, Ann Arbor, MI, 2 Endodontics, Prosthodontics and Operative Dentistry, University of Maryland Dental School, Baltimore, MD, 3 Septodont, Confi-Dental Division, Louisville, CO, 4 Septodont, St. Maur-des Fosses, France

Objective: To determine the mechanical-support-equivalency of three materials when used as bases
below a composite restoration. Base materials must develop adequate stiffness to support the
restoration during masticatory loading. The stiffness of a new calcium silicate dentin substitute (B,
Biodentine, Septodont) and two commercially successful glass ionomer bases (F, Fuji IX, GC America;
V, Vitremer, 3M ESPE) were compared at 4 curing times when an indenting load was applied to a
simulated Class I composite restoration.

Method: A stainless-steel test fixture composed of a base block and two plates each 1.85 mm thick
with a cylindrical hole 4.04 mm Φ drilled thru each was assembled to produce a cylindrical cavity with
one closed end. The test materials were placed into the cavity of the first plate and allowed to cure for
10 min before adding the second plate and an equal layer of light-cured composite (TPH3,
DENTSPLY Caulk). The materials were allowed to cure for 1/2, 1, 2, or 24 H before loading to 1334 N
with a spherical-ended indenter attached to a universal test machine (Instron 5866). The deflection
was determined for both 500 and 1334 N. Results: The composite did not fracture for any material or
condition during loading.

Composite/Base Material Deflection @ 1⁄2 H Curing

Conclusions: The composite applied as early as 10 min after initiation of mixing of Biodentine,
Vitremer or Fuji IX exhibited no fracture when tested 1⁄2 H after initiation of mixing. Deflection of the
composite and Biodentine at 1⁄2 H was greater compared to Fuji IX and similar to Vitremer.
Biodentine has immediate physical properties comparable to other base materials so that it can be
used as a dentin substitute and the tooth restored with composite resin during the same treatment
visit.

Project was funded in part by Septodont.

Poster Session, AADR 2012, Tampa, Florida, USA