Oral dryness, encompassing an individuals’ subjective experience of dry mouth (xerostomia) and objectively measured unstimulated and/or stimulated decreased salivary secretion (hyposalivation), can impair chewing and swallowing and increase the risk of oral diseases, affecting quality of life and well-being. Notably, an individual’s subjective experience of dry mouth does not always align with their salivary secretion rate, suggesting that saliva quality could be of importance. Previous research has examined saliva composition; particularly mucin MUC5B, highlighting the importance of mucin structure for the experience of dry mouth. Findings have been inconsistent, largely because of variations in study populations, saliva and methods used for saliva analysis. This underscores the need for further research. Additionally, earlier studies have explored dentists’ knowledge and clinical management of oral dryness; however, despite its acknowledged clinical relevance, research shows that oral dryness remains an overlooked condition among dental professionals. Research on how dentists and dental hygienists manage oral dryness in dental care in Sweden is limited. Therefore, the overall aim of this thesis was to explore dental professionals’ experiences in managing oral dryness, and to explore associations between xerostomia, clinical signs, salivary secretion rate, and saliva composition in affected individuals. The thesis is based on four studies, where study I is based on a questionnaire, studies II and III are based on semi-structured interviews, and study IV is based on a questionnaire, clinical examinations, and laboratory analyses.

In study I, dentists’ and dental hygienists’ awareness and management of oral dryness were examined, as was the influence of length of professionals’ experience on these aspects. Results showed that older adults were more often asked about their experience of dry mouth than were younger individuals. Dental hygienists encountered individuals with oral dryness more often, asked a larger age span about their experience of dry mouth, measured salivary secretion rate, and provided preventive measures more compared to dentists. Dentists showed greater awareness of saliva function, while dental hygienists showed greater awareness of the causes and complications of oral dryness.

The findings from study I were evaluated, and to some extent confirmed in studies II and III. In study II, dental professionals’ experiences showed that managing oral dryness includes challenges like the heterogeneity of the patient group, barriers to measuring salivary secretion, vague routines, lack of treatment options and a necessity to remain up-to-date of current research; however, dental professionals also applied a patient-centred approach in managing oral dryness, including tailoring questions to the individual, viewing the patient holistically, and engaging in sharing-decision-making. In study III, dentists’ and dental hygienists’ experiences collaborating with physicians showed hindrances to collaboration because of dental subsidy application issues, lack of contact pathways, and perceived limited knowledge among physicians. Dental professionals suggested measures to address these hindrances including taking over responsibility for dental subsidies and calling for physicians to improve the information they give to individuals with oral dryness. Collaboration between dentists and dental hygienists was defined by a resource-optimising approach and by clear roles, with dentists playing a coordinating role and dental hygienists playing the key role in the collaboration.

In study IV, saliva secretion, saliva composition (MUC5B, sialic acid, total protein concentration), clinically assessed oral dryness, and severity of xerostomia were explored and compared between two xerostomia groups with different aetiologies (Sjögren's disease and unspecific dry mouth) and controls. The Sjögren's disease group (n =16) and the unspecific dry mouth group (n =9) had significantly higher sialic acid levels, lower total protein output, and higher clinical oral dryness score (CODS). Xerostomia was more severe in the Sjögren’s disease group compared to the unspecific dry mouth group. Very strong correlation was observed between CODS and both unstimulated and stimulated salivary secretion rates. In the unspecific dry mouth group, the severity of xerostomia showed a very strong correlation with saliva composition (sialic acid, MUC5B, and total protein concentration), whereas moderate correlations were observed between CODS and xerostomia severity, and between CODS and stimulated salivary secretion rate in the Sjögren’s disease group.

This thesis concludes that managing oral dryness in dental care is challenging, but a patient-centred approach may be crucial. The findings indicate that saliva secretion rates, xerostomia severity, saliva composition, and clinically assessed dryness differ across groups with xerostomia of different aetiologies where individuals with Sjögren's disease appear to be more affected. However, further research is needed.