Preservation of arch space is one of the primary objec tives of pediatric dentistry. Premature loss of primary teeth may cause aberration of the arch length, resulting in mesial drift of the permanent teeth and consequent malocclusion. Whenever possible, the tooth with pulp involvement should be maintained in the dental arch free of disease (if it can be restored to function). This chapter deals with preservation of the primary and young permanent teeth with pulp involvement.