Application of Xeros system for 15 days. Lozenge (Malic acid 28.56 mg, Xylitol 421,98 mg, Sodium fluoride 0.55 mg) or Spray (Malic acid 1%, Xylitol 10%, Sodium fluoride 0.05%) 4 times a day. Effects on Xerostomia and Quality of Life were determined before and after application by answering the questionnaires.

Effects of lozenge on hyposalivation and pH variation determined by saliva collection with pre-weighed falcon and a ph electrode at predetermined times during a 20 minute period.

Application of citric acid based Mouthwash (0,33% citric acid) for 15 days four times a day. Effects on Xerostomia and Quality of Life were determined before and after application by answering the questionnaires.

Effects of mouthwash on hyposalivation and pH variation determined by saliva collection with pre-weighed falcon and a pH electrode at predetermined times during a 20 minute period.

Application of Xeros system for 15 days. Mouthwash (Betaine 1.33%, Xylitol 3.30%, Sodium fluoride 0.05%, Allantoin 0.10%) 2 times a day.

Effects on Xerostomia and Quality of Life were determined before and after application by answering the questionnaires.

Application of Xeros system for 15 days. Gel (Betaine 1%, Aloe Vera 0.05%, Xylitol 10%, Sodium Fluoride 0.0033%) before bed.

Effects on Xerostomia and Quality of Life were determined before and after application by answering the questionnaires.

On the day that the system is attributed the subject is asked to use one of the products and saliva is collected. pH variation is determined at fixed intervals during 20 minutes. Time in which salivary pH is below 4.5 is calculated as well as the number needed to treat and the absolute risk reduction.

Before and after usage of both products at home, the Summated Xerostomia Inventory-5 (range 0 to 15) to measure subjective feeling of dry mouth, Oral Health Impact Profile-14 (range 0 to 56) to measure quality of life perception related to the oral cavity. This last questionnaire is further divided into 7 subdomains: functional limitation, physical pain, psychological discomfort, physical disability, psychologic disability, social disability and handicap each ranging from 0 to 14.

In both questionnaires the total score is the result of the sum of the individual scores in each question.

In both questionnaires the higher the score the worse the outcome. The before and after scores obtained are then compared.

While using one of the two products saliva is collected, weighed and salivary flow is determined at fixed times during 20 minutes.