July/August 2016 | Page 25

ABSTRACTS OF POSTER COMPETITION WINNERS 1st Place Winner Title: A New Class of Matrix Metalloproteinase Inhibitor Preserves Dentin Bond Presenter: Kazuma Kitagaito University of Pennsylvania School of Dental Medicine 240 South 40th Street, #7461 Philadelphia, PA 19104 (650) 336-0077 [email protected] Authors: Kazuma Kitagaito1, Nuray Tuloglu2, David Persky3, Haritha Ghanta1, Markus B Blatz1, Abdulhafez Selim3, Marina D’Angelo3, Fusun Ozer1 1. University of Pennsylvania, Philadelphia, USA 2. Osmangazi University, Eskisehir, TURKEY 3. Philadelphia, College of Osteopathic Medicine, Philadelphia, USA Objective: A novel class of therapeutic, the Extracellular Matrix Protection Factor (ECPF), is a selective MMP inhibitor targeting specific family members. This study investigated the influence of MMP-8 selective inhibitor pretreatment on preserving dentinal bond strength after one year in-vitro aging. Methods: 36 human molars, preserved in -80°C, were prepared by creating flat occlusal dentin surfaces for box cavity preparations measuring 5x3x1.5mm. All teeth were randomly divided into three groups (n=12) according to their pretreatment procedures: Control (NT), chlorhexidine (CHX), and ECPF. Prior to pretreatment, all cavities underwent acid etching with 37% H3PO4 (30s). For CHX and ECPF groups, pretreatment of 2% CHX (60s) or 5μg ECPF (60s) followed etching. All teeth were restored using bonding agent (Prelude-one, Danville Materials) and composite-resin built up. Groups were separated into two sets randomly: immediate (IM) and thermo-mechanical aging (TMA). IM set underwent microtensile bond strength (μTBS) testing after 24 hours water storage. For TMA set, the teeth were exposed to thermocycling regimen of 20,000 cycles between 5oC and 55oC, and placed in chewing simulator (240,000 cycles; 50N) to simulate one year of oral conditions. The restorations were vertically sectioned to obtain 1.0 mm2 cross-sectional composite-dentin beams. μTBSs were measured. Data were analyzed by two-way ANOVA and Tukey’s test. Results: μTBS [MPa] Mean±SD Groups NT CHX ECPF IM 20.4±4.1B,a 20.3±3.3B,a 39.6±8.1A,a TMA 21.4±5.6B,a 24.0±7.5B,a 28.9±4.6A,b Different superscript uppercase letters (in row) and different superscript lowercase letters (in column) indicate statistically significant differences (p<0.05). Bond strengths of NT and CHX groups were similar for both IM and TMA sets. However, strengths for both immediate and aged ECPF groups were statistically different against all NT and CHX groups. Conclusion: The application of ECPF pretreatment increased dentinal bond strength after one year in-vitro aging, which yields clinically meaningful differences. However, further investigations are indicated to improve dosage and delivery methods. Funding/Conflict of Interest: Funding: University of Pennsylvania School of Dental Medicine Schoenleber Pilot Grant J U LY / A U G 2 0 1 6 | P E N N S Y LVA N I A D E N TA L J O U R N A L 23