Here is the design of a clinical trial:

Official Title: Evaluation of Photobiomodulation in Salivary Production of Patients With Xerostomy Induced by Anti-hypertensive Drugs

Included conditions:
- Xerostomia

Study Armgroups:
- {'label': 'Photobiomodulation group', 'type': 'ACTIVE_COMPARATOR', 'description': 'Patients will receive 3 applications of low intensity light directly in the region of the three pairs of salivary glands already described. The ArGaAl diode laser, DMC 808nm 4J/point equipment will be used. The parameters that will be used are: Laser Diode ArGaAl, DMC, 808nm, 4J per point, continuously and in contact with the irradiated surface, resulting in irradiance of 3571 mW/cm2, distributed as follows: 6 points in each parotid, 2 points in each sublingual (external) and two in each submandibular (internal), totaling 16 extra oral and 4 intra oral, totaling 20 points. The exposure time will be 40s per point, corresponding to 800s per session and 3600s at the end of the four treatment sessions. The radiant exposure will be 142J/cm2. The first application will be after the stimulated collection of saliva and the following applications will be given once a week for another 2 weeks.', 'interventionNames': ['Radiation: Photobiomodulation']}
- {'label': 'Sham group', 'type': 'SHAM_COMPARATOR', 'description': 'The placebo group will have a simulation of application of the laser, following the same technique as the active group, but with the device turned off. Because it is an infrared light, it is invisible and this will not induce the patient to notice that the device is turned off.', 'interventionNames': ['Radiation: Sham']}

Interventions:
- {'type': 'RADIATION', 'name': 'Photobiomodulation', 'description': 'The parameters are: Laser Diode ArGaAl, DMC, 808nm, 4J per point, continuously and in contact with the irradiated surface, resulting in irradiance of 3571 mW/cm2, distributed as follows: 6 points in each parotid, 2 points in each sublingual (external) and two in each submandibular (internal), totaling 16 extra oral and 4 intra oral, totaling 20 points. The exposure time will be 40s per point, corresponding to 800s per session and 3600s at the end of the four treatment sessions. The radiant exposure will be 142J/cm2.', 'armGroupLabels': ['Photobiomodulation group']}
- {'type': 'RADIATION', 'name': 'Sham', 'description': 'The sham group will have a simulation of laser application, following the same procedures as the active group, but with the device switched off.', 'armGroupLabels': ['Sham group']}

Primary Outcomes:
- {'measure': 'Change from baseline Sialometry (measurement of the amount of produced saliva before and after treatment)', 'description': 'The patient will be instructed to keep the head forward allowing all saliva to passively pass through the collection tube, resting on the lower lip, for five minutes. In the last second, the patient will be instructed to spit out all the accumulated saliva in the collection tube. The amount of saliva and foam will be evaluated and properly recorded. Then, the dimethicone (removal of the air bubbles) will be used to obtain the final result. At the end of the photobiomodulation sessions a sample of saliva will be collected to be compared to the initial sample. The measurement will be made as follows: milliliters of saliva produced per minute. For stimulate sialometry, a sialogogue will be used. The quantity will be classified as follows: Production of normal saliva: 1.5 to 3.0 ml/minute; Light hyposalivation: from 1.05 to 1.45 ml/minute; Moderate hyposalivation: 0.55 to 1.0 ml/minute; Severe hyposalivation: from 0.05 to 0.50 ml/minute; Sialorrhea: above 3.0 ml/min.', 'timeFrame': 'One month.'}

Please estimate the sample size based on the assumption: 
A 2-tailed t test with a significance level of 0.05 was assumed. The test power was set to be greater than 0.80.
2.3
        Sample size
        It is known from published studies that the salivary volume (primary outcome) presents a normal distribution of probabilities, and with a variation coefficient of around 50%. Meanwhile the literature lacks information on the salivary flow difference between irradiated and non-irradiate subjects. Due to the lack of similar published works, the sample size was calculated using estimated effect size and test power as shown in Figure 3.
        
          Figure 3
          
            Statistical power of the hypothesis test as a function of the sample size. Each line was calculated for a different effect size.
          
          
        
        For the sample size analysis we assumed a 2-tailed t test with significant level of 0.05. Figure 4 shows that, for medium (0.750) and large (1000â1250) effect sizes, a minimum of 30 patients per group is sufficient to control statistical variance, ensuring a test power >0.80.
        
          Figure 4
          
            Sites of irradiation: parotid, submandibular, and sublingual salivary gland.
          
          
        
        
          2.3.1
          Inclusion criteria
          Patients over 18 years of age, hypertensive patients taking antihypertensive drugs and those who are associated with xerostomia, will be included, except for any other cause for the condition and provided they sign the free consent form. Patients with a serum level of LDL <160âmg/dL and stage 3 renal disease whose renal function reduced their total capacity by 30% to 60%, but without oral repercussion, may be part of this group.
        
        
          2.3.2
          Exclusion criteria
          Patients with cancer in the oral region, patients in radiotherapy, patients with SjÃ¶gren syndrome, diabetics, patients with stage 4 and 5 renal failure, pregnant women, infants, children under 18 years old, and those with any type of photosensitivity.