the present study depended on laser parameters but both supported that LLLT had beneficial effect on wound
healing after gingivectomy operation. The wavelength is an important parameter to evaluate laser
effectiveness. In this study the wavelength was 685 nm, while in the present study was 850 nm. The power used
in this study was 50 mw applied in a contact with the wound for 4 sessions on day 0, 24h, day 3 and day 7. On
the other hand, the power in the present study was 200 mw in a non-contact method 10 mm away from the
wound site for 4 sessions on day 0, day 3, day 7 and day 14. The irradiated wounds underwent a better healing
process than the wounds from the control group, because of higher collagen production leading to a better
remodeling of the connective tissue and a reduction of the probing depth. The reduction of the probing depth in
the early stages of healing is as very positive finding.
Also, the result of the present study agreed with Kohale et al. [11] conducted a study to assess the effect of
LLLT on wound healing and patient's response after scalpel gingivectomy and results indicated that LLLT
improved wound healing. Forty patients involved in the study, received laser therapy on day 0, day3 and day7
and healing assessed on day 3, day 7 and 1 month after surgery. The difference between this study and the
present study was based on laser parameters but both accelerate wound healing of the gingiva after
gingivectomy. In this study, although the power and the repetition of the laser were less than in the present
study as the power was 100 mw and it had beneficial effect of the healing due to the large wavelength that was
940 nm. As the penetration depth increases with increasing wavelength [12]. The study explained that the
effectiveness of wound healing after LLLT as there were formation and proliferation of newer blood vessels and
fibroblasts in the initial stages of wound healing. LLLT reduce inflammation by lowering the levels of
prostaglandin E2, interleukin‑1 beta, tumor necrosis factor alpha, cellular influx of neutrophils and
granulocytes, oxidative stress, edema, and bleeding.
Also, Reddy et al. [13] compared the efficacy of low-level laser therapy, hyaluronic acid and herbal gel when
used topically after a gingivectomy. They reported that there were statistically significant results observed in
the low-level laser therapy group on wound healing more than hyaluronic acid and herbal gel groups. In this
study 10 subjects received laser on day 1, day 3 and day 7 post surgery. However, laser power of this study was
50 mw for 3 min only with contact method, the LLLT group showed better results due to the large wavelength
as it was 980 nm. On the other hand, the power in the present study was 200 mw in a non-contact method with
10 mm away from the wound site. The study explained that LLLT applied to soft tissues excited specific
metabolic processes in healing wounds. The major changes observed include increased granulation tissue, early
epithelialization, increased fibroblast proliferation, and matrix synthesis. Also, the histological evaluation
showed more mature collagen fibers in the laser group.
Only few studies reported that low level diode laser therapy has not affect wound healing in patients post
gingivectomy that observed and recorded by Damante et al. [14] reported that low-level laser therapy did not
accelerate the healing of oral mucosa after gingivoplasty. The first difference between this study and the
present study was the small sample size as 16 patients in the study with both sides gingivoplasty and one side
used as control so that could affect negatively the results and might make a type of error. The second difference
was the wavelength 670 nm while wavelength of the present study was 850 nm and the penetration depth
increase with increasing wavelength [12]. The third one was the power used in this study 15 mw it was very
small because penetration and absorption of laser light can also be affected by the power output, the greater the
number of photons which penetrate the tissue at any time, the greater the number of photons will be present at
any given depth and higher power densities with shorter irradiation times might be more efficient in the
delivery of LLLT [15], while the power of the present study was 200 mw. The forth one was sessions interval in
this study the laser was applied 48h for 1 week for a total of 4 sessions while the laser applied in the present
study was applied for 2 weeks on day 0, day 3, day 7 and day 14, repeated irradiation increased the proliferation
of fibroblasts [16]. The fifth and last difference was the healing assessed in this study after gingivoplasty and it
was a simple surgical procedure, it had excellent post-operative outcome in most cases and healing was a very
rapid process while the present study assessed the wound healing after gingivoplasty and gingivectomy
operations which is more complex than gingivoplasty alone.
present study was the small sample size as 11 patients in the study with both sides gingivectomy so that might
impair the results while in the present study 40 patients. The second one was sessions interval in this study the
laser was applied 48h for 1 week for a total of 4 sessions while the laser applied in the present study was for 2
weeks on day 0, day 3, day 7 and day 14, repeated irradiation increased the proliferation of fibroblasts. The other
Citation: Mahmoud ES, Abd El-baky AM, Said OM and Hussein HG. Low level diode laser therapy on wound healing post gingivectomy. J Life Sci Biomed, 2020;