Evaluation of pain on use of electrosurgery and diode lasers in the management of gingival hyperpigmentation: A comparative study.

BACKGROUND: Gingival depigmentation is a periodontal plastic surgical procedure whereby the gingival hyperpigmentation is removed by various techniques such as electrosurgery, cryosurgery, abrasion with diamond bur and lasers. The aim of this study was to determine the pain levels during the gingival depigmentation procedure using electrosurgery and lasers.
MATERIALS AND METHODS: Twenty patients, both male and female, between the ages of 20 and 40 years were randomly allocated into two groups of 10 patients each: Those undergoing depigmentation with electrosurgery (Group I) and those by diode lasers (Group II). Patients of both groups were asked to define the level of pain and discomfort by using the Visual Analog Scale (VAS) intraoperatively, 24 h post-operatively and 1 week post-operatively.
RESULTS: Both the groups showed a decrease in the pain levels, which was statistically highly significant 1 week post-operatively when compared 24 h post-operatively. There was a statistically highly significant difference in the pain levels between the electrosurgery and the lasers groups after 24 h (P < 0.001), with the lasers group demonstrating lesser pain and discomfort. Although there was no significant difference between the two groups intraoperatively and 1 week post-operatively on comparison, lesser mean scores were observed for the lasers group.
CONCLUSION: The growing concern for esthetic requires the removal of hyperpigmentated gingival areas to create a confident and pleasant smile, which could be easily attained by using either electrosurgery or lasers. This study concluded that lasers produce lesser pain and discomfort compared with electrosurgery during gingival depigmentation.

RCT Entities:   Population Interventions Outcomes

INTRODUCTION

When a person senses happiness, pleasure or greetings, a smile develops. The harmony of the smile is determined not only by the shape, position and color of the teeth but also by the color of the gingival tissues. The color of the gingiva is produced by the vascular supply, the thickness and degree of keratinization of the epithelium and the presence of pigment-containing cells.[1] Melanin, a non-hemogloblin-derived brown pigment, is the most common of the endogenous pigments and is produced by melanocytes present in the basal layer of the gingival epithelium. There is no difference in the number of melanocytes between fair-skinned and dark-skinned individuals; the variation is related to differences in the activity of melanocytes. The intensity and the distribution of racial pigmentation of the oral mucosa is variable, not only between races but also between different individuals of the same race and within different areas of the same mouth.[23] Gingival pigmentation occurs as a diffuse, deep-purplish discoloration or as irregularly shaped brown and light brown patches. It may appear in the gingiva as early as 3 h after birth and often is the only evidence of pigmentation. The distribution of oral pigmentation in black individuals is as follows: Gingiva 60%, hard palate 61%, mucous membrane 22% and tongue 15%.[4] The gingiva propria is the most frequently pigmented intraoral site.

Gingival depigmentation is a periodontal plastic surgical procedure whereby the gingival hyperpigmentation is removed/reduced by various techniques such as cryosurgery,[2] gingivectomy,[5] free gingival autograft,[6] electrosurgery,[7] chemical agents such as 90% phenol and 95% alcohol,[8] abrasion with diamond bur[9] and lasers.[10]

Patient discomfort during periodontal treatment and post-operative pain and post-operative dentin hypersensitivity are common clinical events associated with many periodontal procedures.[1112] There has been no evidence in the literature comparing the levels of pain and discomfort during different gingival depigmentation procedures.

The aim of this study was to determine the pain levels during the gingival depigmentation procedure using electrosurgery and lasers.

MATERIALS AND METHODS

This study was conducted at the Department of Periodontology and Oral Implantology, Maharishi Markandeshwar College of Dental Sciences and Research, Mullana (India), from August 2012 to April 2013. Inclusion criteria were: Grade 2 gingival pigmentation[13] and Class 1 smile line.[14] Exclusion criteria were: Acute periodontal or pulpal pain, abscesses, dentinal hypersensitivity, dental caries, patients taking analgesics, smokers, pregnant and lactating patients, pathologic gingival hyperpigmentation and systemic diseases associated with healing disturbances, e.g., diabetes and autoimmune diseases.

Sample size was aimed at obtaining a minimum power value of 0.8 to detect a difference in the levels of pain and discomfort between the groups. The sample size calculation determined seven subjects per treatment group. To compensate for possible drop-outs, 10 patients were recruited per treatment group. Twenty patients (12 men and 8 women; aged 20-40 years with a mean age of 28.75 ± 8.08 years) with grade 2 gingival pigmentation and class 1 smile line were chosen to be treated. Patients were randomly allocated into two groups of 10 patients each: Those undergoing depigmentation with electrosurgery (Group I) and those by diode lasers (Group II). The procedures were explained verbally to the patient and verbal and written consent were obtained. The study was conducted in accordance with the Helsinki Declaration of 1975, as revised in 2000.

Group I consisted of five men and five women. For the electrosurgery procedure, topical lignocaine hydrochloride anesthesia was applied in the maxillary and mandibular anterior gingival region. Needle and loop electrosurgical electrodes were used for gingival depigmentation. Light brushing strokes were used and the tip was kept moving all the time [Figures 1 and 2]. Prolonged repeated application of electrode to the tissues was avoided as it induces heat accumulation and causes undesired tissue destruction. As it causes an undesired effect, enough care was taken to avoid contact of current with the periosteum and vital teeth, but in one patient at one point the tissue fenestrated [Figure 3]. No periodontal dressing was placed. Patients were instructed to avoid eating hot and spicy foods for the first 24 h following the procedure and were discharged from the dental office to perform normal daily activity. No analgesic was prescribed.

Figure 1

Pre-operative view showing melanin gingival pigmentation in the maxillary anteriors to be performed with electrosurgery

Figure 2

Intraoperative view showing de-epithelization in the maxillary anterior gingival area with electrosurgery

Figure 3

Intraoperative view showing the area where gingival tissue was fenestrated during the electrosurgical procedure

Group II consisted of seven men and three women. For the laser procedure, the patients and the staff were protected from laser by wearing manufacturer's spectacles. Highly reflective instruments or instruments with mirrored surfaces were avoided as there could be reflection of the laser beam. Topical anesthesia lignocaine hydrochloride was applied in the maxillary and mandibular anterior gingival regions. A semiconductor diode surgical laser unit of wavelength 980 nm, in gated -pulsed mode (between 2 and 3 watts), flexible fiberoptic hand piece with filament of 320 μm in diameter was used for depigmentation. The tip was moved using brush stroke to prevent heating of the tissue. The procedure was performed in the cervico-apical direction on all pigmented areas [Figures 4 and 5]. To enhance visualization, normal saline-soaked cotton or gauze was used to remove the epithelial remnants. The area was irrigated using saline. Air and water were used to cool the surgical site. No periodontal dressing was placed. Patients were instructed to avoid eating hot and spicy foods for the first 24 h following the procedure and were discharged from the dental office to perform normal daily activity. No analgesic was prescribed.

Figure 4

Pre-operative view showing melanin gingival pigmentation in the maxillary anteriors to be performed with lasers

Figure 5

Intraoperative view showing de-epithelization in the maxillary anterior gingival area with lasers

Patients of both groups were asked to define the level of pain and discomfort by using the Visual Analog Scale (VAS). VAS is a scale of 10 cm that is used to grade sensitivity, labeled at the extremes with no pain at the 0 cm end of the scale and severe pain at the 10 cm end of the scale.[15] Subjects were asked to place a mark on the 10 cm line at a location between no pain and severe pain ends. Pain levels were evaluated at three time periods: Intraoperative, 24 h post-operatively and 1 week post-operatively. Each patient was given a single assessment sheet for all three time periods separately so that the patient could not refer to the previous VAS markings.

Student's paired t-test was used to evaluate changes of VAS scores within the groups at different time periods: Intraoperative, 24 h post-operatively and 1 week post-operatively. A non-parametric test (Mann - Whitney test) was used to compare the VAS between Group I and Group II at different time periods.

RESULTS

Patients of both the groups tolerated the procedure well, but two of the Group I patients complained of pain initially, particularly while eating or drinking. The wounds were initially covered by a carbonized layer and, after 24 h, by a thick fibrinous layer. The clinical keratinization was completed at 4 weeks after treatment, and the treated areas were similar in color to other areas of the gingiva that did not present clinical pigmentation [Figures 6 and 7].

Figure 6

Post-operative view showing depigmentated maxillary anterior gingival area performed with electrosurgery after 4 weeks

Figure 7

Post-operative view showing depigmentated maxillary anterior gingival areas performed with lasers after 4 weeks

VAS data of all 20 subjects of both the groups are shown in Tables 1 and 2. Both the groups showed an increase in pain levels, which was statistically significant (P < 0.05) 24 h post-operatively when compared intraoperatively [Tables 3 and 4]. Analysis showed statistically highly significant differences in the pain levels of both the groups, with decrease in pain levels 1 week post-operatively when compared 24 h post-operatively [Tables 3 and 4]. On comparison of the intraoperative and 1 week post-operative scores, a statistically significant difference was observed for both the groups [Tables 3 and 4].

Table 1

VAS scores of Group I (electrosurgery)

Table 2

VAS scores of Group II (lasers)

Table 3

Intragroup comparison of VAS scores for Group I (electrosurgery) at different time periods: Intraoperative, 24 h post-operative, 1 week post-operative

Table 4

Intragroup comparison of VAS scores for Group II (lasers) at different time periods: Intraoperative, 24 h post-operative, 1 week post-operative

Analysis showed a statistically highly significant difference in the pain levels between the two groups 24 h post-operatively (P < 0.001), with the laser group demonstrating lesser pain [Table 5]. Although there was no significant difference between the two groups at intraoperative and 1 week post-operatively on comparison, a lesser mean score was observed for the laser group [Table 5]. The comparison of the VAS scores between the two groups at all three time periods is shown in Figure 8.

Table 5

Intergroup comparison of VAS scores between Group I (electrosurgery) and Group II (lasers) at different time periods: Intraoperative, 24 h post-operative, 1 week post-operative

Figure 8

Comparison of the Visual Analogue Scale scores at different time periods between the two groups

DISCUSSION

An electrosurgical unit was used for the procedure, which is used upon the biterminal principle that grounds the patient in the circuit. According to Oringer's “Exploding cell theory,”[16] it is predicated that electrical energy leads to the molecular disintegration of melanin cells of the operated and surrounding sites. Thus, electrosurgery has a strong influence in retarding migration of melanin cells. The depigmentation is performed using the sides as well as the tip of the electrode and, thus, sometimes, inadvertently damages the adjacent tissues.[17] Electrosurgery is not absorption specific within a target tissue and is unable to control the depth of necrosis in the tissue being treated. These high temperatures causes a depth of necrosis of more than 500 μm; the inability to control such depth of necrosis is a significant disadvantage to use of electrosurgical techniques for tissue ablation.[18] Electrosurgery has its own limitation in that its repeated and prolonged use induces heat accumulation and undesired tissue destruction.

Research into selective photothermalysis and treatment of pigmented lesions has been performed with different types of lasers, including 1060, 532 and 355 nm Nd: YAG, 351 nm Excimer, 890, 980 nm Diode and 488, 514 nm Argon lasers.[3] In this study, a 980 nm Diode laser was chosen to eliminate the melanin gingival hyperpigmentation. The diode laser is a solid-state semiconductor laser that typically uses a combination of Gallium (Ga), Arsenide (Ar) and other elements, such as Aluminum (Al) and Indium (In), to change electrical energy to light energy. These lasers are small, light weight and compact hence portable as compared with the other solid-state and gas lasers that are bulky and difficult to transport, may have a warm time to several minutes and require a cooling system as well as requiring regular maintenance.

Laser treatment of pigmented lesions requires melanocytes to lie within the range of penetration of the laser and to contain melanin in order to absorb and convert light energy into heat by photothermalysis. The diode lasers exhibits thermal effects using the hot-tip effect caused by heat accumulation at the end of the fiber; thus, the depigmentation is performed using only the tip of the fiber. Lasers allow for controlled cutting with a limited depth of necrosis. This is due to their inherent ability to be absorbed within the chromophores (wavelength-specific light-absorbing substances) with a specific target tissue and, thus, cause a tissue-specific ablation layer by layer and cell by cell.[19] Diode lasers are well absorbed by melanin and hemoglobin and other chromophores present in periodontally diseased tissues. The laser energy is transmitted through water and poorly absorbed in hydroxyapatite. These properties of the diode lasers make them an excellent choice to use in a periodontally involved sulcus that has dark inflamed tissue and pigmented bacteria. The laser parameters (pulse duration, hertz, joules) must be modified based on many factors, with tissue pigmentation being one crucial factor.[19]

Environmental factors such as noise and temperature potentially influence pain perception.[2021] Thus, each procedure was scheduled at the same time of the day and pain measurements were performed within the same closed operatory with distraction-free surroundings.

This study is a first of its kind to evaluate pain levels using the VAS to compare electrosurgery and diode lasers for gingival depigmentation, although there are some studies that compared the scalpel technique and electrosurgery.[2223] Kaarthikeyan et al.[24] assessed pain using a VAS in patients undergoing gingival depigmentation by the scalpel technique and 970-nm diode laser surgery and found a statistically significant difference between the levels of pain, with the laser group demonstrating lesser pain intraoperatively compared with the scalpel group. However, there was no difference in the levels of pain 24 h post-operatively and 1 week post-operatively between the two groups.

In the present study, the laser group patients experienced lesser pain compared with the electrosurgery group, which can be attributed to the analgesic effects of these diode lasers due to a disruption of Na+-K+ pump in the cell membrane, resulting in a loss of impulse conduction or simply due to an ablation of the nerve endings because of protein coagulum formation.[25] The advantages of lasers over conventional surgical procedures are: Dry and bloodless surgery, instant sterilization of the surgical site, reduced bacteremia, reduced mechanical trauma, minimal post-operative swelling and scarring and minimal post-operative pain.[26] However, lasers do have some disadvantages, such as: Loss of tactile feedback and expensive and sophisticated equipment, making the treatment expensive.[10]

CONCLUSION

Within the limitations of this study, it can be concluded that diode lasers are shown to be a safer and effective treatment modality to provide optimal esthetics and enhanced comfort with lesser pain to the patients during the treatment for gingival hyperpigmentation compared with electrosurgery. More data are required on comparative techniques to ensure the long-term predictability and success.