Aetna considers electric reflex salivary stimulation (Salitron System) experimental and investigational for the treatment of xerostomia (dry mouth) or for any other indications because its effectiveness has not been established.

Chronic xerostomia can be caused by Sjogren's syndrome, certain medications or therapeutic irradiation. It can cause difficulty in eating dry foods, swallowing and wearing dentures; and susceptibility to dental caries, oral pain and frequent infections. Proponents of electrostimulation as a treatment option postulate that stimulating the tongue and the roof of the mouth simultaneously will result in impulses to all residual salivary tissues, major and minor, in the oral and pharyngeal regions, thus causing salivation.

Although the FDA approved the Salitron System in 1988 to treat xerostomia secondary to Sjogren's syndrome, the Agency for Health Care Policy and Research (AHCPR) advised in a 1991 assessment that there were “insufficient data to determine the clinical effectiveness of this modality of salivary production, or to identify those xerostomic patients who would benefit from the procedure” (Erlichman, 1991). One published study (Weiss et al, 1986) reported some degree of response after three stimulation sessions of three minutes each in 24 patients with xerostomia related to Sjogren's, radiation therapy, drugs or unknown etiology. However, there was no control group, information on the duration of response, quantitative assessment of salivary response, or intermediate or long-term assessment of effectiveness.

Another report, a double-blind study (Steller et al, 1988) noted a statistically significant mean increase in post-stimulation whole saliva flow between subjects (n = 29) using active and placebo stimulators. However, this was due mainly to the responses of three subjects who showed marked increases in their whole saliva flow rate during the study. Of the active study arm, only one subject showed evidence of a cumulative response over the four weeks of the study. Further research of electrical stimulation of salivary flow is needed to ascertain its role in the treatment of Sjogren's patients with xerostomia.

Talal and colleagues (1992) reported that electrical stimulation improves salivary function of patients with Sjogren's syndrome. In this placebo controlled study, patients received three treatments (2 weeks apart, over a 4-week period) with an active device (n = 34) or a placebo device (n = 37). Patients using active devices showed a statistically greater increase in salivary production than patients using placebo devices. Moreover, patients demonstrated significant improvement in other symptoms such as difficulty in swallowing as well as burning tongue. The major shortcomings of this study were (i) it is unclear whether the control group was age-matched, (ii) lack of long-term assessment of effectiveness, and (iii) the number of patients in the active device group who did not respond to treatment was not disclosed, and the range or standard deviation for pre- and post-stimulation whole salivary flow rates was not given.

The role of electrical stimulation in the management of patients with xerostomia awaits the outcomes of randomized, double-blind, controlled clinical studies with large sample sizes and long-term follow up. In many reviews on the management of patients with xerostomia (Cooke, 1996; Fox, 1997; Davies, 1997; Mariette, 2002; Fox, 2003), salivary electrostimulation was not mentioned as a method to manage patients with this condition.

Strietzel et al (2007) evaluated the safety and effectiveness of a recently developed electro-stimulating device mounted on an individualized intra-oral removable appliance. The device, containing electrodes, a wetness sensor, an electronic circuit and a power source, was tested on patients with xerostomia in a cross-over, randomized, sham-controlled, double-blinded, multi-center study (n = 23; 10 with primary Sjogren's syndrome, 7 with medication-induced xerostomia, and 6 with idiopathic xerostomia). Electrical stimulation and also sham were delivered for 10 mins to the oral mucosa, in the mandibular third molar region. Oral dryness was measured by the sensor. As the primary outcome, sensor dryness and xerostomia symptom changes as a result of device wearing were assessed, and compared between active and sham modes. In addition, side-effects were recorded. Electro-stimulation resulted in a significant decrease in sensor dryness, leading to a beneficial effect on patients' subjective condition. No significant adverse events were observed. However, 30.4 % patients reported the sham mode to be more effective than the active mode. The authors stated that these findings are encouraging enough to continue developing and investigating the miniature electrostimulating device mounted on a dental implant.