Comparison of two different depigmentation techniques for treatment of hyperpigmented gingiva.

INTRODUCTION: Demand for cosmetic therapy of gingival melanin pigmentation is common. Re-pigmentation after gingival depigmentation is an important point. The aim of this study is to evaluate the effect of surgical scraping and electrosurgery on postoperative pain, healing and recurrence of pigmentation.
MATERIALS AND METHODS: Fifteen patients with esthetic concern related to black gums were selected and treated by surgical scraping with respect to right quadrant and electrosurgery with respect to left quadrant. Patients were recalled post-operatively to evaluate healing and recurrence of pigmentation. Each patient was asked to complete the Visual Analogue Scale (VAS) index cards 2 and 24 hours postoperatively.
RESULTS: In the initial post-operative period, VAS index cards showed that the discomfort and pain level associated with electrosurgery was significantly higher than conventional scalpel surgery (P < 0.05). Clinically delayed healing was observed in the electrosurgically treated site. Electrosurgery showed better results as compared to epithelial excision for recurrence of pigments. At the end of 15 months, 7 sites in the scalpel excision group showed recurrence, whereas only 4 site showed recurrence in the electrosurgically treated group.
CONCLUSION: The methods used here produced desired results and above all, the patients were satisfied with the outcome. Increased pain level and clinically delayed healing was associated with electrosurgery as compared to scalpel surgery, whereas repigmentation occurred more frequently in scalpel-treated sites.

INTRODUCTION

The color of the gingiva plays an essential role in overall esthetics and appearance of an individual. The normal color of gingival tissues is pale pink, but part of the population has a gingival melanin pigmentation caused by excessive melanin deposition by the melanocytes mainly located in the basal and suprabasal cell layers of the epithelium.[1]

A close relationship between gingival pigmentation and ethnic groups is observed.[2] In dark skinned and black individuals, increased melanin production in the skin and oral mucosa is a result of genetically determined hyperactivity of their skin and mucosal melanocytes.[3] Earlier studies have shown no significant difference in the density of distribution of melanocytes between light-skinned, dark skinned and black individuals.[4] However, melanocytes of dark skinned and black individuals are uniformly highly reactive, in light-skinned individuals, melanocytes are highly variable in reactivity.[567]

Clinical melanin pigmentation of the gingiva may cause esthetic problems and embarrassment, particularly if the pigmentations are visible during speech and smiling.[89] Demand for cosmetic therapy of gingival melanin pigmentation is common and various methods including bur abrasion, surgical scraping, cryotherapy, electrosurgery and laser therapy have been reported. Selection of a technique should be based on clinical experience and individual preferences.

One of the first and still popular technique to be employed is the surgical removal of undesirable pigmentation using scalpels.[10] The procedure essentially involves surgical removal of gingival epithelium along with the layer of underlying connective tissue and allowing the denuded connective tissue to heal by secondary intention.[10] The new epithelium that forms is devoid of melanin pigmentation.[10] Electrosurgery has been commonly used and is even preferred over other technique by many technicians.[11] A controlled, high frequency electrical current in the range of 1.5-7.5 Megahertz[12] is used for sculpting or modifying oral soft tissue.

Each technique has its own advantages and disadvantages. Re-pigmentation after gingival depigmentation is an important point of which clinician should be aware. Reports of re-pigmentation are quite limited and varied.[13] In the present study, depigmentation of hyperpigmented gingiva was done using electrosurgery and surgical scraping. The aim of the study is to evaluate the effect of the two procedures on the basis of post-operative pain, healing and recurrence of pigmentation.

MATERIALS AND METHODS

Ethical clearance from the institutional review board was obtained prior to start of the study. All the patients were informed about the protocol and those who agreed to participate in the study were made to sign an informed consent. 15 patients in the age group 17-25 years, 6 males and 9 females, selected from the outpatient Department of Periodontics, Institute of Dental Studies and Technologies, Modinagar, participated in this clinical trial. These patients had esthetic concern related to black gums [Figure 1]. Patients with current history of systemic disease, pregnant and lactating women were excluded from the study.

Figure 1

Preoperative photograph showing pigmented gingiva

A split-mouth design was adopted and, therefore n = 15 for both groups. The maxillary arch was divided into 2 segments.

Segment I - right first premolar to right central incisor, treated with surgical scraping.

Segment II - left first premolar to left central incisor, treated with electrosurgery.

Both the segments were treated on the same appointment by single operator.

Surgical Protocol

Under perfectly aseptic conditions and infiltration anesthesia, the pigmented gingival epithelium from right first premolar to central incisor was scraped using no. 15 BP blade [Figure 2]. Care was taken to include the epithelium at the tip of the interdental papilla and at the mucogingival junction on the other end. Hemostasis was obtained with sterile gauze and direct pressure. On the other side, electrosurgery was used for depigmentation of the left maxillary anterior gingiva till second premolar [Figure 3]. A loop electrode was used in a light brushing strokes for de-epithelizing the gingiva. Care was taken to remove any remnants of pigmented areas that were left out. The surgical wound on both the sites was protected by a periodontal pack. Post-operative analgesics and antibiotics were prescribed. Oral hygiene instructions were given and the patient was advised to use 0.12% chlorhexidine mouthwash for immediate post-operative 2-week period to aid plaque control. Pack was removed after 1 week and the area was debrided. Patients were re-evaluated at 7th/8th, 12th/13th, 21st/22nd, 30th/31st days and then 3, 6, 12 and 15 months post-operatively.

Figure 2

De-epithelialization with surgical scraping for Segment I

Figure 3

De-epithelialization with electrosurgery for Segment II

Clinical parameters recorded

Facial complexion: The subjects were divided into 3 groups on the basis of their facial complexion, viz, fair, wheatish and dark.

Gingival pigmentation: Pre-operative and post-operative observations about the gingival pigmentation were made according to Dummett-Gupta Oral Pigmentation Index.[14]

0 - No clinical pigmentation (ping gingiva)

1 - Mild clinical pigmentation (mild light brown color)

2 - Moderate clinical pigmentation (medium brown or mixed pink and brown color)

3 - Heavy clinical pigmentation (deep brown or bluish black color).

Score in each tooth was taken including one full interdental papilla

Visual Analogue Scale: Was used to quantify pain levels and patient's discomfort. The VAS consisted of a horizontal line of 10 cm (100 mm) with two end-points representing ‘no pain’ and ‘worst pain imaginable’. Patients are asked to rate their pain by placing a mark on the line corresponding to their current level of pain. The distance along the line from the ‘no pain’ marker is then measured with a ruler giving a pain score out of 10.

0: No pain

0.1-3: Slight pain

3.1-6: Moderate pain

6.1-10: Severe pain.

Each patient was given the instructions to complete the VAS index cards two and 24 hours after the procedure.[15]

Wound Healing: The healing was evaluated visually at 7th/8th, 12th/13th, 21st/22nd, 30th/31st days using hydrogen peroxide (H2O2) test.[16] The area to be evaluated was dried and 3% H2O2 was applied to the healing wound. The negative peroxide test for two consecutive days indicated complete healing. The scores were as:

Negative (-): No bubble formation (complete healing)

Positive (+): Bubble formation (incomplete healing).

Statistical analysis

Statistical analysis was carried out using Statistical Package for Social Sciences (SPSS Inc., Chicago, IL, version 11.0 for windows). For qualitative variables, mean and standard deviation were calculated. Means were compared for two groups using Student t test. For time-related variables, paired t test and for intergroup comparisons, unpaired t test was applied.

RESULTS

In the present study, out of the total 15 patients treated (age group 17-25 years), 6 were males and 9 were females. Categorization of the subjects on the basis of facial complexion resulted in 3 patients being considered in dark, 10 in wheatish and 2 in fair categories.

Post-operative evaluation of the VAS score revealed that the discomfort and pain level associated with electrosurgery was significantly higher than conventional surgery at 24 h postoperatively [Table 1].

Table 1

Clinical evaluation of VAS pain scores presented as mean±SD

In the initial post-operative period delayed healing was observed in the electrosurgically treated site. The peroxide test measures the quality of epithelial barrier.[16] Although, the peroxide test was positive on 7th and 8th day for both the treatment sites, the amount of bubbles visible on scalpel treated sites were substantially less than electrosurgically treated sites [Table 2]. After first week slight redness was observed around the margins of the surgical site treated by conventional technique whereas the site treated with electrosurgery showed generalized reddened areas. Bubble formation (with the use of H2O2) was seen in electrosurgically treated site even at 12th and 13th day depicting incomplete epithelialization [Table 2]. The significantly superior healing at scalpel treated sites was visually appreciable at this time [Figure 4]. The considerably lesser time required for healing by scalpel treated sites resulted in lesser post-operative discomfort to the patients. Both the areas healed well after 1 month. Pigmentation was absent from newly formed epithelium. Upon final healing gingiva appeared pale pink, which was very satisfactory for the patient.

Table 2

Clinical evaluation of wound healing: Bubbles formation at different time intervals to confirm epithelial barrier formation

Figure 4

2 weeks post-operative photograph showing delayed healing at electrosurgically treated site

At 15 months post-surgery, all 3 of the dark patients (100%), 4 out of 10 wheatish patients (40%) and none out of the 2 fair patients (0%) reported with re-pigmentation [Table 3]. The pattern of recurrence in all the cases was patchy in distribution [Figure 5]. Electrosurgery showed better results as compared to epithelial excision. In scalpel-treated areas, 1 out of 15 sites showed recurrence within 3 months and 6 sites within 15 months. Whereas in sites treated with electrosurgery none of the sites showed recurrence within 3 months and only 4 out of 10 sites showed recurrence within 15 months [Table 4]. Pre- and post-surgical comparison of gingival pigmentation scores revealed highly significant difference in both the treatment groups [Table 5].

Table 3

Gingival melanin pigmentation scores on the basis of facial complexion

Figure 5

6 months post-operative photograph showing re-pigmentation in both the segments

Table 4

Number of patients with re-pigmentation

Table 5

Pre- and post-surgical comparison of gingival pigmentation scores

DISCUSSION

Gingival hyperpigmentation is a major concern for a large number of patients and many a times forces the patient to seek cosmetic treatment. Although several techniques are currently in use, the scalpel technique is still the most widely employed as it is most economical compared to other techniques, which require more advanced armamentarium and is therefore highly recommended in consideration of the equipment constraints in developing countries.[4]

The present study had a split-mouth design which is an excellent method to determine the clinical relevance of comparison of the two depigmentation techniques to remove gingival pigmentation. By comparing the techniques within a subject, it minimizes the influence of numerous inter-subject factors, such as age, facial complexion etc.

In this study, patients demonstrated more pain and discomfort in the electrosurgically treated sites during the first 24 h postoperatively. The VAS is an established method for assessing pain or discomfort responses of patients. The VAS as a method of pain measurement has been reviewed extensively and was found to be a reliable method.[1718] Although, this method of pain assessment has its own limitations like the validity of VAS measures may be dependent on the instructions used for patients and subjects,[19] measuring the distance along a horizontal or vertical line may be time consuming[19] and method is subjective.[1718]

Our study revealed delayed epithelialization in electrosurgically treated sites. The peroxide test measures the quality of epithelial barrier.[16] Application of H2O2 results in bubble formation on partly healed wounds because of incomplete epithelial barrier formation.[16] The completely formed epithelial barrier in healed wound results in little or no bubble formation.[16] Enzyme catalase present in underlying connective tissue acts on H2O2 to release water and oxygen.[16] An intact epithelial barrier prevents the diffusion of H2O2 into the connective tissue, thus resulting in liberation of little or no oxygen.[16] Various studies of wound healing after electrosurgical excision of gingival tissue compared with conventional periodontal scalpels have yielded conflicting results. Some investigators reported no significant differences in gingival healing after electrosurgery and conventional surgery.[15] Tipton et al.[20] reported that the scalpel wounds are stronger and healing progressed much faster than electrosurgery wounds. Manivannan et al.[21] attributed this delay in wound healing to decreased blood flow by the 7th day in electrosurgically treated areas. They also stated that wound healing is influenced by revascularization rate, preservation and reconstruction of microvasculature.

The color of gingiva has been correlated with facial complexion. Ponnaiyan[2] reported that dark-skinned subjects had heavy gingival pigmentation, whereas fair-skinned subjects had mild pigmentation. It has been observed that in dark complexion people, after surgical depigmentation, the reappearance of pigmentation is more than people with fair complexion. This could be attributed to the increased intrinsic melanogenesis in dark complexion people.[2] In our study, 100% of the dark patients and 40% wheatish patients reported with re-pigmentation 9 months post-surgery. None of the fair complexioned patients had recurrence of pigments. Billingham[22] proposed that the possible reason may be the rate of melanogenesis, which is intrinsically maintained and is higher in dark-complexioned patients as compared to light-complexioned patients.

In our study, 7 sites in the scalpel excision group showed recurrence, whereas only 4 site showed recurrence in the electrosurgically treated group. The superior efficiency of electrosurgery over epithelial excision could be explained based on exploding cell theory. According to the theory it is predicted that the electrical energy leads to molecular disintegration of melanin cells present in basal and suprabasal cell layers of operated and surrounding sites.[23] Thus electrosurgery has a strong influence in retarding migration of melanin cells from the locally situated cells.

The large variation in time of re-pigmentation may be related to the technique used and the race of the patient. The mechanism of re-pigmentation is not understood and there is little information on the behavior of melanocytes after surgical injury, but according to migration theory, active melanocytes from the adjacent pigmented tissues migrate to treated areas, causing re-pigmentation.[24] Re-pigmentation may also be attributed to the melanocytes which are left during surgery as stated by Ginwalla et al.[25] These may become activated and start synthesizing melanin. Ginwalla reported re-pigmentation in 50% of their cases between 24 and 55 days. Dummett and Bolden[26] operated pigmented gingiva by gingivectomy procedure in 9 cases. Re-pigmentation occurred in 67% of the areas, as early as 33 days after surgical removal. Perlmutter and Tal[24] have also reported gingival re-pigmentation that occurred 7 years after removal of gingival tissues in one patient. Tal et al.[27] and Tal[28] did not observe re-pigmentation until 20 months after cryosurgical depigmentation. No re-pigmentation was found in any of the four patients treated by Atsawasuwan et al.[29] at 11-13 months after gingival depigmentation using Nd: YAG laser. Nakamura et al.[30] described depigmentation with CO2 laser in 10 patients. No re-pigmentation was seen in the first year, but 4 patients showed re-pigmentation at 24 months. Tal et al.[13] observed no re-pigmentation occurring in any of the patients with Er: YAG laser after 6 months.

The pattern of recurrence in all the cases with re-pigmentation was patchy in distribution and due to its mild intensity the results can be considered to be satisfying for the patients. The benefits of both the treatment modalities include ease of usage, effectiveness and convenience in dental clinics. Further research is required on re-pigmentation to study the factors affecting rate and length of time required for recurrence of pigmentation. Research should also focus on finding a solution for preventing the recurrence and till then repeated depigmentation should be done to eliminate the unsightly pigmented gingiva.

CONCLUSION

The methods used here produced desired results and above all, the patients were satisfied with the outcome. Discomfort and pain level associated with electrosurgery was higher than conventional surgery. Also, clinically delayed healing was observed in the electrosurgically treated site, whereas re-pigmentation occurred more frequently in scalpel-treated sites.