Tabela 2 – Salivary Sampling.
The parameters used in photobiomodulation are important to achieve the
expected result. In the present report, the patient showed improvement
in symptoms with vascular photobiomodulation at the red wavelength
(660nm), although infrared in direct local application under the
salivary glands is usually indicated in cases of xerostomia. This result
is in agreement with studies that demonstrated the systemic action of
vascular photobiomodulation (Lizarelli, 2023; Mikhaylov, 2015).
Further to the wavelength, other parameters are important such as the
power, which was 100mW, the energy per point which was 180J and the
equipment beam area (0.04 cm²). It’s important to note that all
parameters must be informed so that clinicians and readers know exactly
what treatment was performed and that, if they so wish, they can
reproduce the same protocol with their patient. The number of
irradiations must also be questioned. There are no reports in the
literature in which the effect of the benefit of photobiomodulation is
sustained for more than 7-10 days, however the ideal minimum interval
time still needs to be defined (Abueva, 2022; Sousa 2019; Brzak, 2018).
Many authors report in their studies a reduction in xerostomia and an
improvement in salivary flow, pH, IgA content and saliva buffering
capacity. Some studies claim that PBM is able to regenerate salivary
gland tissue (Plavnik, 2003A review suggests the effectiveness of PBM in
the treatment of xerostomia (Sousa, 2019). A study in humans observed
the effects of PBM on salivary glands of patients with xerostomia, where
the authors used different parameters, infrared laser λ = 830 nm and red
laser λ = 685 nm, and found an improvement in flow in both, being even
better in patients treated with λ = 830 nm, this effect was observed in
the long term, suggesting a regenerative effect on the salivary glands
(Brzak, 2018). However, there is not enough evidence to support the
claim of a cumulative or regenerative effect of PBM in a general sense,
as studies were carried out on few patients or without control groups
(Golez, 2022).
Close communication between the dentist (who has to deal with adverse
effects) and the prescribing physician is necessary to obtain the best
outcome for the patient (Wolff, 2017). Although xerostomia was a
commonly reported outcome, objectively measured salivary flow rate was
rarely reported. Furthermore, xerostomia was assessed primarily as an
adverse effect rather than the primary outcome of medication use.
(Wolff, 2017).
In this clinical case presented, the patient’s psychiatric treatment is
not expected to end, so the protocol is now applied in a preventive
manner and not just to cure the symptoms. Studies have observed a
cumulative effect of salivary gland repair when locally irradiated. With
the prevention of xerostomia, the patient achieved a clear increase in
her quality of life, reported by herself with the following words:
“Dry mouth can’t be resolved even with water, but the laser has
improved it a lot. I stayed really well for a week, I was fine for
several days, so much so that I couldn’t wait to do it again, because I
was feeling good and wanted to stay well”.
At each session, the patient reported a reduction in symptoms, which
encouraged her to attend, as she noticed that she no longer needed to
wake up to drink water. With the prevention of xerostomia, the patient
achieved a clear increase in her quality of life, demonstrating that
vascular photobiomodulation can be an interesting low-cost non-invasive
treatment.
The effect of laser exposure was demonstrated not only in fluids
subjected to direct irradiation, but also in fluids from organs located
far from the irradiation zone, providing evidence of one of the
potential mechanisms behind the proven systemic effect of PBM
(Mikhaylov, 2015).
In a systematic review, it can be concluded that there is sufficient
evidence about the beneficial effect of PBM on unstimulated salivary
flow and other salivary parameters. However, there is not enough
evidence to prove that the effects of PBM are long-lasting enough to
improve patients’ quality of life (Golez, 2022).
It was observed that laser therapy has good acceptance in the dental
field, where it has been widely used in xerostomy conditions, due to its
positive tissue biomodulation effects (Loncar, 2011). The advantages of
PBM known to date include improvement in epithelial cell mitosis,
enlargement of salivary ducts and stimulation of protein synthesis in
submandibular glands (Abueva, 2022), in addition to low-intensity laser
therapy being effective in reducing mucosal inflammation. oral, being
important in the treatment of hyposalivation (Oliveira, 2022).