There are great risks of diseases in the ageing population, and oral diseases are no exception. Poor oral health has profound negative impacts on the quality of life. It is therefore crucial to include the oral health perspective in the care for older adults. To meet the challenges associated with oral health in the ageing population, a formative intervention was launched. The intervention, called the TAIK project (=“Dental hygienist in a municipality organization”, in Swedish: Tandhygienist i kommunal verksamhet), meant that six dental hygienists served non-clinically as oral health consultants in five Swedish municipal organizations. The intervention formed an infrastructure and platform for work that benefits the ageing population and created a new basis for decisions regarding oral health in homecare. The aim of this paper is to explore how aspects of collaboration in an interprofessional and interorganizational intervention may lead to expansive learning. Expansive learning forms the theoretical framework of this study. The dental hygienists and the local head nurses were interviewed individually in-depth. Reflection documents from the dental hygienists were also part of the analyzed data. The conclusion is that the formative intervention was reliant of change which created a foundation for reciprocal understanding that led to expansive learning between dental care and municipal healthcare, with resilience and empowerment as crucial factors