Dental Back pressure porosity can be avoided by: A Using asbestos liners B Placing the sprue at least one quarter inch away from the end of casting ring C Preventing rapid heating of the investment in burnout oven D Using a short and wide sprue 💡 Explanation Back pressure porosity can be avoided by: ✓ Correct Answer: B. Placing the sprue at least one quarter inch away from the end of casting ring