CAUSES OF MICRO-LEAKAGE Material An article written by Bagis et al. compared micro-leakage between silorane-based resin composite and nanohybrid-based resin composite restorations. The results of the study concluded that the enamel and dentin margins for silorane-based resin composite restorations showed no leakage. The nano-hybrid-based resin composite restorations presented with varying levels of leakage. Applying the findings of this study, a clinician may want to consider use of a silorane-based resin composite to limit micro-leakage experienced by the patient. Placement Instrumentation A study appearing in Operative Dentistry compared micro-leakage associated with a variety of instrument combinations used for composite placement. Four instrument combinations were assessed; a metal matrix with wooden wedge, a transparent matrix with reflective wedge, a metal matrix with wooden wedge and light tip, and a metal matrix with wooden wedge and bio-glass cylinder. The study found that exclusive use of a metal matrix with a wooden wedge, as compared to a transparent matrix and a reflective wedge, significantly increases marginal leakage. Using a conical tip, or other similar light-conducting instruments, significantly reduces micro-leakage to a level equivalent to that of a transparent matrix and reflective wedge. Applying the findings of this study, a clinician should no longer continue to solely use a metal matrix and wooden wedge. Intermediary Flow layer A study published in the Journal of Dentistry assessed cervical enamel micro-leakage with and without an intermediary flowable resin-based composite (RBC) layer for the incremental restoration of mesio-occluso-distal (MOD) cavities. Use of an intermediary flowable resin-based compo... ... middle of paper ... ...ent. 2007;35(6):482-9. 5. Schneider H, Busch I, Busch M, Jentsch H, Häfer M. Effect of operator-specific handling on tooth-composite interface and microleakage formation. Oper Dent. 2009;34(2):200-10. 6. Venturini D, Cenci MS, Demarco FF, Camacho GB, Powers JM. Effect of polishing techniques and time on surface roughness, hardness and microleakage of resin composite restorations. Oper Dent. 2006;31(1):11-7. 7. Pongprueksa P, Kuphasuk W, Senawongse P. Effect of elastic cavity wall and occlusal loading on microleakage and dentin bond strength. Oper Dent. 2007;32(5):466-75. 8. Fugaro OJ. COMMENTARY. Effect of prerestorative home-bleaching on microleakage of self-etch adhesives. J Esthet Restor Dent. 2010;22(3):193. 9. Khoroushi M, Fardashtaki SR. Effect of light-activated bleaching on the microleakage of Class V tooth-colored restorations. Oper Dent. 2009;34(5):565-70.