Objectives: To assess the effects of topical dry mouth products (toothpaste and mouthwash) containing olive oil, parsley oil, provitamin B5, allantoin, betaine and xylitol in Primary Sjögren's syndrome patients with xerostomia.

Subjects and Methods: A double-blinded, placebo-controlled, randomized design where participants were randomly assigned at baseline test or placebo products. Participants used the products 3 times/day/28 days. The investigators used Visual Analog Scale for xerostomia and Oral Health Impact Profile-14, baseline and after treatment, to assess the possible improvement.

The investigators conducted a randomized double-blind placebo controlled study among participants with Sjögren's syndrome who attended to the Oral Medicine Specialist Degree Program at the School of Dentistry at Complutense University in Madrid. The study was conducted in accordance to the principles of the Helsinki Declaration. This study followed the guidelines established by the Consort Statement.

Participants. All participants had a full medical history about Primary Sjögren's syndrome, where their rheumatologist detailed how the correct diagnosis was made according to American-European Consensus Group 2002 criteria. Demographic and Primary Sjögren's syndrome characteristics were collected. Stimulated and unstimulated whole saliva were collected following the drainage method at baseline by a single trained clinician blinded to the treatment. The saliva was collected before giving study instructions between 8-10 am. Hyposalivation was present when unstimulated whole saliva was less than 0.1 ml/min or stimulated whole saliva was less than 0.7 ml/min.

Preparations. The company Biocosmetics provided the test and placebo products. Placebo preparations were in identical white bottles (250mL) and white toothpastes (50mL) like study products. These preparations (study or placebo) did not contain irritant substances. The placebo included the same excipients resulting in solution similar to the experimental one in colour, flavour and density. All ingredients were equal in parts except the active products that were only present in the study products: betaine, xylitol, allantoin, Olea Europaea Fruit Oil (olive oil), Panthenol (provitamine B5) and Carum Petroselinum Seed oil (parsley oil). Test and placebo products contain sodium fluoride (mouthwash 250ppmF- and toothpaste 995ppmF-).

Interventions and instructions to participants. Participants were randomized to receive study or placebo mouthwash and toothpaste. Before starting treatment, participants were instructed to rinse with 7mL of mouthwash (study or placebo) for 60 seconds after meals (3 times/day). After rinsing the mouth, patients were instructed to brush their teeth with 0.5 g of study or placebo toothpaste following the Bass brushing technique for 3 minutes. We gave all the patients the same ultra soft dental brush (CS5460 Curaprox, Curaden AG, Kriens, Switzerland). The products had to be used for 28 days (4 weeks). Participants were informed that the use of any oral hygiene or xerostomia products apart from the intervention was prohibited. After giving the instructions, the investigators gave the patients the corresponding bag containing the study or placebo products, which was completely closed.

Sample size. The sample size was calculated considering a previous study that applied the same products. It was estimated that, at least, 50% of the test group would improve; so with an alpha of 0.05 and a statistical power of 80%, 12 subjects would be required in each group.

Randomisation. Participants were randomly assigned to one of treatments (study or placebo) in a 1:1 ratio using a computer-generated algorithm stratified by using a fixed block sized of 4. The company performed the randomisation and prepared the products in opaque bags following the results of randomization. The participants received the correspondence bag following the sequence of study entry.

Blinding. The study and placebo products had an identical appearance and were packaged identically. The sacs were numbered consecutively from 1 to 28. The company prepared and numbered the bag and all the participants were blinded to the treatment. Blinding was revealed after all participants finished the trial and all the data were collected.

Statistical methods. All the analysis was done using SPSS version 22.0 (SPSS Inc. New York, NY, USA). Statistical analysis included basic descriptive statistics. Comparison of continuous variables between test and placebo groups was done using Mann-Whitney U-test. Comparison of categorical variables was done using Chi-square test or Fisher's exact test. Wilcoxon signed-rank test was used to determine whether the intragroup decreases in Visual Analogue Scale and Oral Health Impact Profile 14 were statistically significant. Differences were considered significant if p was less than or equal to 0.05.

Inclusion Criteria:

• 18 years of age or older, pSS patients diagnosed according to the AECG-2002 criteria, patients suffering xerostomia sensation, willingness to participate in the study, mentally and physical ability to participate and complete the study

Exclusion Criteria:

• patients who received or are being treated with head and neck radiotherapy, chemotherapy, pregnant and breast-feeding women and patients who were using other topical or systemic treatments for xerostomia.

The study and placebo products had an identical appearance and were packaged identically. The sacs were numbered consecutively from 1 to 28. The company prepared and numbered the bag and all the participants were blinded to the treatment. Blinding was revealed after all participants finished the trial and all the data were collected.