The effect of low-level laser therapy on salivary glands in patients with xerostomia.
OBJECTIVE
The aim of this study was to investigate the effect of low-level laser irradiation on the secretory function of salivary glands in 34 patients with xerostomia (dry mouth).


BACKGROUND
Xerostomia, a common complaint of oral dryness within the elderly population, is caused by a reduction in normal salivary secretion due to different causes. Treatment is aimed at increasing salivary flow, although in most cases it remains palliative.


METHODS
In this study, laser light from a pulsed Ga-As laser operating at 904 nm was applied bilaterally on each salivary gland area: extraorally on the parotid and submandibular gland areas and intraorally on the sublingual gland area. The operational probe distance from the irradiated area was 0.5 cm resulting in an irradiance of 246 mW/cm(2). The exposure time was 120 sec per daily treatment during 10 consecutive days. The average energy density per exposure was 29.5 J/cm(2). The control group consisted of 16 patients who were treated with 15 mL of a 2% citric acid solution applied as a mouth rinse for 30 sec.


RESULTS
The average difference in the amount of salivation (dQ-sal, mL/min) before and after laser therapy increased linearly from dQ-sal = 0.05 mL/min on the first day, up to dQ-sal = 0.13 mL/min on the last (10th) day of therapy. In the control group, the average dQ-sal initially demonstrated a gradual increase, with a reversal of the trend toward the end of the therapy period and eventually yielding no correlation between the duration of therapy and dQ-sal.


CONCLUSIONS
The results of our study indicate that the effects of low-level laser therapy on salivary glands are not only stimulating, but also regenerative to a degree since the glandular response to the same amount of applied laser energy increased linearly over time.
Department of Oral Medicine, School of Dental Medicine, University of Zagreb, Zagreb, Croatia. loncar@sfzg.hr
Božana
B
Lončar
Marinka Mravak
MM
Stipetić
Marinka
M
Baričević
Dubravko
D
Risović
D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D028022:Low-Level Light Therapy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D011829:Radiation Dosage; D012016:Reference Values; D018570:Risk Assessment; D012469:Salivary Glands / Q000378:metabolism / Q000528:radiation effects*; D012472:Salivation / Q000528:radiation effects; D012720:Severity of Illness Index; D016896:Treatment Outcome; D014987:Xerostomia / Q000175:diagnosis / Q000532:radiotherapy*