Prevalence and frequency of alcohol consumption in the patients included in the study It will be determined using the CAGE questionnaire originally developed by Ewing and validated in 1974 by Mayfield. It is named after the 4 items it has: C: Cut down; A: Annoyed; G: Guilty; E: Eye opener. It is often used because of its brevity. It is evaluated according to the number of affirmative answers, the greater the dependence. Thus: 0-1: Social drinker; 2: Risk consumption; 3: Harmful consumption; 4: Alcohol dependence

Quantification of the plasma expression of the GGT markers.GGT (gamma-glutamyl transferase test) which determines the existence of liver damage.It will be analysed in the first visit, after 6 months and a year. Patients will have a sample of peripheral venous blood taken for the study of this marker. To avoid bias in the analysis, all samples will be taken at the Oral Medicine Unit and sent to the same reference laboratory for evaluation and quantification.

Quantification of the plasma expression of the TDC markers. TDC (tricyclodecane dimethanol, carbohydrate-deficient transferrin) measures a cumulative effect of alcohol consumption, appearing after regular intake of 50-80 g of ethanol per day for at least one week and returning to normal after 15 days of abstinence. It will be analysed in the first visit, after 6 months and a year. Patients will have a sample of peripheral venous blood taken for the study of this marker. To avoid bias in the analysis, all samples will be taken at the Oral Medicine Unit and sent to the same reference laboratory for evaluation and quantification.

The Fagerstrom nicotine dependence test (FTND) will be used (Fagerstrom, 1990). It is one of the most widely used questionnaires for assessing nicotine dependence. It consists of 6 items and has a cut-off point of 6 or more to determine the presence of nicotine dependence.

Through clinical examination at all visits: stable, worsening or oncological event We will also record the location and size of the lesions.

We will use the OHIP-14sp (Oral Health Impact Profile - Spanish version), validated by León et al in 2014.A numerical value between 0 and 56 will be obtained, implying that the highest score will represent the greatest effect of oral disorders on the interviewee's quality of life.

It will be evaluated by comparing the stages in which the patients are found throughout the follow-up visits.RCQ (Readiness to Change Questionnaire) is an instrument that attempts to measure and operationalize the phase in which patients are in order to modulate the therapeutic intervention by adapting it to the corresponding motivational level. It consists of 12 items and three motivational stages are described (pre-contemplation, contemplation and action). Each stage is represented by 4 items. For each question asked, there are five response options ranging from total disagreement to total agreement. There is a Spanish version validated by Rodriguez-Martos et al that we will use.

Evaluation of the effectiveness of the brief intervention on alcohol consumption applied by dentists in comparison with the usual advice. The satisfaction questionnaire (CSQ-8) will be used, quantitatively determining the effectiveness.CSQ-8: is a quality evaluation questionnaire for the services provided. Originally published by Atkisson et al., but there is a Spanish version that has been validated. The questionnaire is based on 8 questions to be answered by patients at the end of their stay in the service on a visual analogue scale. Each question is evaluated between 1 and 4 points and satisfaction is directly related to the number of points, so that the sum of these points is a semi-quantitative variable that takes values between 8 and 32 points.This will be done on the last visit to patients in group 1.

It will be evaluated by quantitatively comparing the quality of life values at the different stages of monitoring, segmenting the analysis by arm/group and by reduction in consumption.We will use the Oral Health Impact Profile (OHIP) as a measure of people's perception of the social impact of oral disorders on their well-being. To measure oral health-related quality of life, Slade and Spencer in 1994 based themselves on 49 questions known as OHIP-49 , in 1997 Slade developed a short form with 14 questions (OHIP-14) that showed good reliability, validity and accuracy and has been widely used worldwide for various research purposes. This study will use the OHIP-14sp (Oral Health Impact Profile - Spanish version), validated by León et al in 2014.

It will be evaluated by quantitatively comparing the quality of life values at the different stages of monitoring, segmenting the analysis by arm/group and by reduction in consumption.We will use the VAS ,this is the most widely used scale for measuring pain. It consists of a straight line of 10cm with the words "No Pain" on the left hand side and "The Worst Pain imaginable" on the right hand side and the patient must mark on the line the amount of pain he or she is suffering from. By measuring the distance in centimetres, a figure of 0 to 10 can be deduced. A value of less than 4 in VAS means mild or mild-moderate pain, a value between 4 and 6 implies the presence of moderate-severe pain, and a value of more than 6 implies the presence of very severe pain.

TSG-I (unstimulated). This test is an adaptation of the Schrimer test (a test used to evaluate tear production) and the procedure involves folding the end of the filter paper strip at a right angle before inserting it into the oral cavity under the tongue. When the lips are closed, they come into slight contact with the polyethylene bag. The saliva that collects on the lingual fence during the 5 minutes of the test slowly soaks into the strip. After this time, the strip is removed from the mouth and the result should be read immediately. It will be evaluated on all visits.

TSG-II (stimulated). This test is performed after the TSG-I by applying drops of 4% citric acid solution in the oral cavity.It will be evaluated on all visits.