Dental caries has been on the increase in many developing nations and even in the poor communities in the developed nations. Dental restorations have been used to manage dental caries, especially, in their early cavitation stages of its development. Atraumatic restorative treatment (ART) has been used as an alternative treatment approach for dental caries in areas where traditional dental treatment is lacking as a result of economic difficulties. Restorations placed in single-surface dental cavities using this ART approach, have been found to have good survival rates in the short to medium term. However, the survival of restorations placed in multi-surface cavities using the same method has been poor. It is important to establish the factors behind the poor survival of these multi-surface restorations, and to use the results of such findings to improve on their survival. This monograph discusses some of the factors influencing the survival rate of proximal ART restorations (example of multi-surface restorations) placed in primary molars.