The invention is directed to an improved dental composition useful in the repair of cavities, apex repairs, root perforations and root canals. Disclosed is a dental composition and dental composition additive which have improved handling characteristics, for example improved viscosity and setting time. The addition of effective amounts of a modified cellulose and calcium chloride to available dental repair compounds, such as mineral trioxide compound, results in the improved dental composition without affecting the other characteristics of the dental repair compound.