Comparison of two methods for sialometry: weighing and volume techniques

| The composition of saliva is essential for the oral cavity homeostasis, therefore, the decrease in salivary flow leads to consequences, such as an increase of dental caries, dry mouth and lips, dysgeusia, dysphagia, gingivitis, halitosis, mastication problems, oral mucositis, oral pharyngeal candidiasis, sleeping and speaking difficulties and traumatic oral lesions. The objective of this study was to evaluate the efficacy of the sialometry technique by weighing in comparison to the sialometry technique by volume. Fifty patients without previous complaint of xerostomia and/or hyposalivation were selected at the Oral Medicine Clinic, Dentistry School, University of São Paulo, Brazil. All samples were collected between 9 am and 10 am and the whole saliva was collect stimulated and unstimulated. Six cotton rolls were prepared, divided into three pairs and placed in different universal dispensers of a random brand, they were weighed in a previously calibrated analytical balance (FA-2104N CELTAC). The sialometry test was performed in three steps: unstimulated salivary flow, salivary flow with stimulation of 1% citric acid solution and stimulation of 1% citric acid solution every 30 seconds. The results of the weighing method were compared to the standard method. There was no significant statistical difference between the two types of collection and 100% of the participants expressed their preference for the weighing method. DESCRIPTORS | Saliva; Salivary Elimination; Salivary Glands; Salivation. RESUMO | Comparação de dois métodos de sialometria: técnicas de pesagem e volume • A composição da saliva é essencial para homeostase da cavidade oral. Assim sendo, a diminuição do fluxo salivar pode levar ao aumento da incidência de cáries, boca seca, alteração no paladar, alteração na deglutição, gengivite, halitose, problemas mastigatórios, mucosites, candidíases, problemas no sono, fala e lesões orais traumáticas. O objetivo deste estudo foi avaliar a técnica de sialometria por peso em comparação com a técnica tradicional de sialometria por volume, com coleta de saliva estimulada e não estimulada. Cinquenta pacientes com ou sem queixa prévia de xerostomia ou hipossalivação foram selecionados na clínica de Estomatologia da Faculdade de Odontologia da Universidade de São Paulo, Brasil. Todas as coletas foram realizadas entre 9 e 10 horas da manhã. Seis rolos de algodão foram separados e divididos em três pares e colocados em três diferentes coletores plásticos universais, sendo cada conjunto pesado previamente em balança analítica calibrada. O teste de sialometria foi realizado em três etapas: fluxo salivar sem estimulação; estimulado com 1% de ácido cítrico em aplicação única; e estimulado com aplicação de 1% de ácido cítrico a cada 30 segundos até completar 2 minutos. Esses resultados por peso foram comparados com o método de sialometria por volume tradicional. Não houve diferença estatística observada entre os dois métodos de coleta e 100% dos pacientes preferiram a coleta realizada com roletes de algodão. DESCRITORES | Saliva; Eliminação Salivar; Glândulas Salivares; Salivação. CORRESPONDING AUTHOR | • Celso Augusto Lemos-Júnior Department of Stomatology, School of Dentistry, University of Sao Paulo • Av. Professor Lineu Prestes, 2227 São Paulo, SP, Brazil • 05508-000 E-mail: calemosj@usp.br • Received Nov. 17, 2016 • Accepted July 12, 2017 • DOI http://dx.doi.org/10.11606/issn.2357-8041.clrd.2017.122887 Comparison of two methods for sialometry: weighing and volume techniques 2 ● Clin Lab Res Den 2017: 1-7 INTRODUCTION The salivary glands are part of the large collection of glands within the endocrine system of human beings, they are responsible for maintaining the balance of the stomatognathic system through saliva production.1 Saliva is essential to the homeostasis of the oral mucosa and some substances found in whole saliva help to maintain the integrity of oral tissues. Mucin is the main product of the submandibular gland, sublingual gland and minor glands, it is responsible for providing lubrication and protection for the mucous membranes.2 Statherin is responsible for maintaining high levels of calcium available, thus improving the teeth remineralization and histatins that have antimicrobial proprieties.3-5 Therefore, the decrease in salivary flow can cause consequences, such as an increase of dental caries, dry mouth and lips, dysgeusia, dysphagia, gingivitis, halitosis, mastication problems, mucositis, oralpharyngeal candidiasis, sleeping and speaking difficulties and traumatic oral lesions.6,7 With the increase in life expectancy, there are more complaints about the dry mouth sensation, xerostomia, from the geriatric population due to the increased use of medications, and systemic diseases.8,9 There are studies that sought to prove that salivary flow decreases with aging, and this decrease is known to have a remarkable effect on the life quality of older adults.9 Hyposalivation is manifested by a reduction in salivary flow and included in the etiology are Sjögren Syndrome, uncontrolled diabetes mellitus, HIV, lupus erythematosus, rheumatoid arthritis, Parkinson’s disease, head and neck radiation therapy and eating disorders.10 According to Ship et al.11, the inhibition of acetylcholine binding to muscarinic receptors on the acinar cells is responsible for the development of an anticholinergic effect, leading to an impact on the quality and quantity of salivary output. These malfunctions must be accurately diagnosed, and this has led to the development of easy and precise methods of diagnosis, providing fast results so an effective therapy can be implemented, and the prognosis of the malfunction can be favorable. Sialometry is the most common method to diagnose salivary flow malfunctions. Hyposalivation, for example, is diagnosed based on the salivary flow measured by sialometry and the result must be under 0.1 mL/min of non-stimulated saliva.1,12,13 The objective of this study was to evaluate the efficacy of sialometry technique by weighing in comparison to the sialometry technique by volume. In addition, we also evaluated the acceptance of the method by the patient, ease of using the method and comparison of the results of both weighing and volume techniques. METHODS Fifty patients were selected at the Oral Medicine Clinic, Dentistry School, University of São Paulo, Brazil. This study was approved by Research Ethics Committee of the institution. All samples were collected between 9 am and 10 am, the participants were instructed not to eat, drink or brush their teeth at least 2 hours before the collection. The age of the participants ranged from 20 to 50 years. The inclusion criteria were that subjects should not present complaints of xerostomia or have used any medication that could interfere in salivary flow or of xerostomic potential such as: antihypertensive and psychotropics. All volunteers agreed to participate in this study, they signed an Informed Consent Form and answered a questionnaire regarding their habits, general health, xerostomia and medication. Six cotton rolls were prepared, divided into three pairs and placed in different universal dispensers of a random brand. The whole set was Sacon MB • Esteves CV • Florezi GP • Gonçalves AF • Pannuti CM • Lemos-Júnior CA • Clin Lab Res Den 2017: 1-7 ● 3 weighed in a previously calibrated analytical balance (FA-2104N CELTAC) with a variation of less than 0.001 g (Figure 1). Whole saliva was collected by spit method, a funnel was linked into a graduated lab cylinder (Figure 2). All samples were centrifugated to obtain the supernatant saliva that can be used for analyses. Figure 1 | A funnel was inserted into a graduated lab cylinder to collect saliva by volume Figure 2 | Cotton rolls were prepared, divided into three pairs and placed in different universal dispensers of a random brand The sialometry test was performed in three steps. First, the patients were instructed to swallow all saliva present in their oral cavity, then, two previously weighed cotton rolls were placed on each side of the floor of the mouth. The subject could not swallow for two minutes, the rolls were then removed and put into the universal dispenser be weighed again. Five minutes after this procedure we applied the standard method, which consisted of the patient spitting saliva into the lab cylinder for five minutes, without stimulation (P1 test). The second step was performed ten minutes later. On the second step the salivary flow was stimulated with 1% citric acid solution. Two drops of solution were poured onto the dorsum of the tongue and the patient was asked to swallow the saliva immediately. The standard sialometry test was performed again as previously detailed (P2 test). The third step was performed ten minutes later. The third step (P3 test) consisted of hyperstimulation of salivary production. Two drops of citric acid were poured onto the dorsum of the tongue and the patient was asked to swallow the saliva immediately. Subsequently, the last two cotton rolls were placed in the mouth of the volunteer, and for two minutes we applied two drops of citric acid in the same location, resulting in a total of eight drops. The set was weighed and the difference in weight was converted into millimeters per minute (mL/min). The standard collection method was performed with stimulation every 60 seconds for five minutes. All data obtained were converted into mL/min. Table 1 | Differences between methods (cotton rolls × standard test) Cotton test Standard Sialometry Duration of each phase 2 minutes 5 minutes Procedure P1 Salivary flow without stimulation Salivary flow without stimulation P2 Previous stimulation with 1% citric acid Previous stimulation with 1% citric acid P3 Stimulation with 1% citric acid every 30 seconds Stimulation with 1% citric acid every 60 seconds Comparison of two methods for sialometry: weighing and volume techniques 4 ● Clin Lab Res Den 2017: 1-7 RESULTS The