Background The most advocated clinical method for diagnosing salivary dysfunction is to quantitate unstimulated and stimulated whole saliva (sialometry). Since there is an expected and wide variation in salivary flow rates among individuals, the assessment of dysfunction can be difficult. The aim of this systematic review is to evaluate the quality of the evidence for the efficacy of diagnostic methods used to identify oral dryness. Methods A literature search, with specific indexing terms and a hand search, was conducted for publications that described a method to diagnose oral dryness. The electronic databases of PubMed, Cochrane Library, and Web of Science were used as data sources. Four reviewers selected publications on the basis of predetermined inclusion and exclusion criteria. Data were extracted from the selected publications using a protocol. Original studies were interpreted with the aid of Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool. Results The database searches resulted in 224 titles and abstracts. Of these abstracts, 80 publications were judged to meet the inclusion criteria and read in full. A total of 18 original studies were judged relevant and interpreted for this review. In all studies, the results of the test method were compared to those of a reference method. Based on the interpretation (with the aid of the QUADAS tool) it can be reported that the patient selection criteria were not clearly described and the test or reference methods were not described in sufficient detail for it to be reproduced. None of the included studies reported information on uninterpretable/intermediate results nor data on observer or instrument variation. Seven of the studies presented their results as a percentage of correct diagnoses. Conclusions The evidence for the efficacy of clinical methods to assess oral dryness is sparse and it can be stated that improved standards for the reporting of diagnostic accuracy are needed in order to assure the methodological quality of studies. There is need for effective diagnostic criteria and functional tests in order to detect those individuals with oral dryness who may require oral treatment, such as alleviation of discomfort and/or prevention of diseases.

Purpose: The aim of the present study was to assess the occurrence of reported subjective oral dryness in relation to objective sialometric values in a randomly selected group and a dental care seeking group. Materials and Methods: A questionnaire assessing subjective oral dryness was sent out to a randomly selected sample of 200 individuals. The dental care seeking group was recruited from among patients attending the Faculty of Odontology, Malmö University. A total of 200 patients were asked to participate in the present study. In total, of 312 individuals (78%) who completed the survey, 157 agreed to participate in the complementary clinical examination that included measures of salivary flow rate. Results: The reported subjective oral dryness was 20% and 28.6% for the randomly selected group and the dental care seeking group, respectively. No statistically significant differences were found between the two study populations with regard to percentage of reported subjective oral dryness, and stimulated and unstimulated salivary flow rates (P > 0.05). In the dental care seeking group, individuals reporting subjective oral dryness presented ‘a small degree of abrasion in the dentine in the incisor region’ to a greater extent (P < 0.05). No statistically significant association between subjective oral dryness and unstimulated and stimulated salivary flow rates was found in either of the studied populations (P > 0.05). Individuals identified with subjective or objective oral dryness presented to a greater extent a history of oral rehabilitation compared to individuals who showed no indication of oral dryness. Conclusions: No association between sialometric measures and subjective report of oral dryness was found in the present study.

To understand the protective functions of saliva secreted from different glands in the masticatory process, it is of interest to study its viscoelastic properties. Characterization of saliva samples are not that easily performed in a clinical setting, since most of the experimental techniques and instruments available are developed for research purposes. The aim of this study was to characterize how the viscoelastic properties of saliva can be measured and monitored using two laboratory instruments. Unstimulated whole saliva from 11 healthy volunteers was characterized using two instruments, an ARES-G2 rheometer and a Bohlin Oscillating Cup Rheometer. Measurements performed on unstimulated human whole saliva showed that the ARES rheometer will in linear viscoelastic conditions of the sample give absolute viscoelastic numbers of undisturbed saliva whilst the BOCR can be used to give an indication of gel strength, gel formation, and gel stability in viscoelastic samples being sheared in their non-linear viscoelastic region by introducing a Saliva Gel Strength Index, SGSI. Both methods clearly illustrate the presence of viscoelastic properties in saliva.