It is a therapeutic challenge to find the suitable treatment for the atrophic/erosive OLP disease, because although there are many medications for this potentially malignant disease, not all are successful in alleviating the symptoms of OLP lesions (Mahdavi et al. 2013; Misra et al. 2013).
In the present study, the efficacy of triamcinolone acetonide paste in reducing the signs and symptoms of OLP was compared to that of LLLT using diode laser.
Corticosteroids remain the most frequently and reliably used medications for the treatment of symptomatic OLP, where triamcinolone acetonide is the most common commercial topical steroid used. However, considering the chronic nature of the disease, patients may develop unwanted side effects or may be unresponsive or resistant to this long-term or often repeated type of treatment (Amirchaghmaghi et al. 2015).
Recently, LLLT has been used successfully for the treatment of OLP. In a prospective study, low-level laser irradiation given to unresponsive OLP patients demonstrated significant decrease in clinical signs and symptoms with no side effects observed (Cafaro et al. 2010). Also, 19 females who had OLP in their tongues reported reduction of pain, discomfort, and lesions’ size after receiving LLLT (Cheng et al. 2012). In another study, more favorable clinical and symptomatic results were achieved in patients receiving LLLT in comparison to those treated with CO2 laser (Agha-Hosseini et al. 2012).
No statistical significant difference was seen between the corticosteroid and laser groups regarding age and gender in the present study population with a noticed prevalence in females which agrees with other reports (McCartan and Healy 2008; Gupta and Jawanda 2015; Cafaro et al. 2010).
Diode laser (980 nm) possesses a deep power of penetration reaching about 1.5 mm (Cheng et al. 2012). Application of diode will increase the temperature of the affected tissues to above 50° and less than 100° causing blanching of the affected mucosal tissue and protein denaturation which in turn will destroy the affected epithelial tissues with its surface antigen (van der Hem et al. 2008). Re-epithelization occurs within 3 weeks after removal of the epithelium by the laser and any feeling of discomfort when in contact with food or liquid disappears (Fornaini 2012).
A 970-nm diode laser was used in the present study for the treatment of OLP because from an optical view, a diode laser in this wavelength has a more superficial action than the 810- and the 904-nm laser which can be more beneficial in treating erosive and atrophic OLP lesions (Cafaro et al. 2014; Byrnes et al. 2005). Setting the exposure time at 4 min was decided after a pilot study on five patients, aiming at achieving max benefits with minimal post-exposure side effects. Patients received two laser sessions per week with a maximum of ten sessions which is in accordance with several previous studies (Cafaro et al. 2010; HH et al. 2011; Misra et al. 2013). Two watts of power was used since using higher power would decrease the cellular proliferation, thus slowing the healing process (Sattayut et al. 2013).
In our comparison, both treatment modalities demonstrated reduction of VAS and RAE scores; however, statistical analysis revealed lower mean VAS and RAE scores in the triamcinolone acetonide group when compared with those of the diode laser group. Moreover, 50% of the patients treated with steroids demonstrated total improvement, while only 16.7% of patients demonstrated total improvement in the laser group.
The lower VAS and RAE scores seen in the corticosteroid group can be attributed to the anti-inflammatory effect of steroids causing suppression of the T cell action, a function which is specific to the autoimmune nature of OLP where T lymphocytes play the major role in the pathogenesis of the disease (Gonzalez-Garcia et al. 2006; Xia et al. 2006).
On the other hand, LLLT as diode laser has a biostimulatory effect consisting of vasodilatation, increasing cellular proliferation, activation of fibroblasts, and neutrophils and decreasing the number of inflammatory mediators, thus aiding in resolution of inflammation and enhancing wound healing. Reduction of pain is caused by the ability of laser to alter the individual’s pain threshold, enhance aggregation of beta-endorphins and encephalins in the tissues, and decrease the C-fiber activity (Misra et al. 2013; Shirani et al. 2009; Cavalcanti et al. 2011).
This biostimulatory mechanism of laser appears to be host-dependent (acting by stimulation of the reparative process of the individual) in opposition to the specific suppressing function of T cells of steroids, which might explain the better results reducing VAS, RAE scores, and the superior improvement seen in the steroid group compared to the laser group seen in this work. Our results can be compared to a prospective case series of 30 patients affected by OLP, who received a 980-nm diode laser 18, where 60% of the patients had a total resolution and 33.3% a partial resolution and no resolution of the lesions at all in 6.6% of patients (van der Meij and van der Waal 2003). In the present work, no statistical significant difference was seen between the improvement parameters in the two groups, where 16.7% of the patients showed total improvement in the laser group, with 66.7% demonstrating partial improvement and 16.7% demonstrating no improvement. The group treated with triamcinolone paste demonstrated 50% partial improvement and 50% total improvement in OLP patients. This is in agreement with a previous study where the OLP group treated with triamcinolone acetonide showed equal cases of clinical complete and partial remission (50%) (Thongprasom et al. 2007). Also, another work comparing the efficacy of fluocinolone acetonide (FAO) with that of triamcinolone acetonide in the management of symptomatic OLP for 4 weeks revealed that 13 of 19 patients could be effectively cured with FAO whereas only 8 of 19 patients (50%) were cured with triamcinolone acetonide, coinciding with the 50% total improvement results seen in our study (Thongprasom et al. 1992). In a similar study comparing the effectiveness of topical steroid versus LLLT, 63% of patients using laser therapy had more than 50% lesion improvement; however, laser therapy was as effective as topical corticosteroids with reduction of pain, appearance, and severity scores in both groups with no significant differences found between them (Akbulut et al. 2013), which is in accordance with the non-statistical difference seen in improvement parameters in our work.