Assessment of clinical outcomes and patient response to gingival depigmentation using a scalpel, ceramic bur, and diode laser 980 nm

Gingival color plays a crucial part in facial aesthetics and contributes to the entire appearance of an ideal smile [1]. Various factors influence gingival color, including the tissue’s blood supply, epithelial thickness, keratinisation degree, and particles like melanin, melanoid, oxyhemoglobin, carotene, and iron [2].

Melanocytes originating from the neural crest are responsible for melanin production. Melanocytes typically reside in the epithelial basal and suprabasal layers. In humans, they establish close connections with 30 to 40 keratinocytes, enabling melanocytes to release melanin into the keratinocytes. Melanocyte activity, along with other variables, predominantly determines the level of pigmentation [3].

Certain physiological or pathological factors have the potential to trigger gingival hyperpigmentation. Although physiologic hyperpigmentation is entirely harmless, some individuals encounter aesthetic concerns consequently, with black gums being the prevailing manifestation [4]. These individuals typically aspire to eliminate gingival coloration to enhance the aesthetic appeal of their smile. Gingival hyperpigmentation (GHP), or “black gum,” constitutes one of the contributing elements that significantly impact how someone looks when they smile [5]. Several treatments, such as gingivectomy, mucosal removal with a scalpel, abrasion techniques, free gingival grafts, chemical approaches involving caustic chemicals, electrosurgery, cryotherapy, and newly developed lasers, have been used to achieve pigmentation-free gingiva [4].

The scalpel technique, which involves eliminating the gingival epithelium and a layer of connective tissue, is one of the earliest and most popular methods for gingival depigmentation. Subsequently, this will allow the stripped connective tissue to heal by secondary intention, producing an epithelium devoid of melanin pigmentation [6]. The wound heals faster with this procedure but is more painful [7‐9].

Ceramic trimmer burs were initially introduced in dentistry for gingivoplasty. However, recently, they have also been used to treat gingival hyperpigmentation. These trimmers are composed of mixed ceramics, including zircon-dioxide ceramic that has been partially stabilized with yttrium and ceramics made of aluminum. They offer a smooth, delicate incision, and the heat generated ensures effective hemostasis, minimal bleeding, and almost no risk of necrosis [10].

Since the 1970s, lasers have been extensively used in medical and dental fields for various surgical techniques [11]. It has been claimed that employing different lasers is dependable, safe, and practical, often resulting in reduced postoperative pain and bleeding. Additionally, it can sculpt, cut, and remove gingival tissues [12].

Two proposed approaches have been suggested, based on the specification of wavelength absorption, for laser gingival depigmentation. In the first surgical/ablative method, the gingival epithelium, which contains melanin, is ablated. This method can be employed at any surgical wavelength. The second method, on the other hand, is non-invasive or non-ablative. It involves the degranulation or denaturation of melanin without removing the gingival epithelium. This is achieved by using a laser with a particular wavelength, like a visible diode laser (445 nm) or a near-infrared diode laser (810 nm) [13].

Several studies have compared using a ceramic trimmer bur and a diode laser for gingival depigmentation. However, neither technique yielded significantly different results regarding aesthetic satisfaction or pain, as measured by the Visual Analog Scale (VAS) [14, 15].

According to the existing literature, there needs to be a consensus on which technique is superior. Thus, the present study aims to compare the clinical outcomes of gingival depigmentation operations with a traditional scalpel, ceramic trimming bur, and diode laser techniques.

Twenty-four participants with gingival hyperpigmentation completed the study after 1 week of observation. None of the individuals left or stopped receiving treatment during the follow-up intervals. No patients reported unbearable pain, significant swelling, or adverse symptoms that warranted exclusion. Without excluding anyone, the participants’ collected data were statistically analyzed.

The comparison between groups at each time point (12 h, 4 days, and 7 days) and across the various time points for each group was performed on the variables. There was no statistically significant difference at baseline between groups for all clinical parameters.

Black gum complaints and requests for depigmentation are popular, even though none of these symptoms poses a medically problematic risk. Many treatment modalities are available for gingival depigmentation, including the scalpel technique, cauterization, cryotherapy, diamond burs, and lasers [26‐29].

Using scalpel for depigmentation offers certain advantages, such as faster healing, lower cost, and the need for fewer instruments. However, scalpel surgery can cause bleeding during and after the procedure, and it requires the use of a periodontal dressing to protect the area of surgery for 7 to 10 days [30].

The ceramic trimmer mentioned in the literature for gingivoplasty has recently been utilized for depigmentation treatment. Soft tissue trimmers offer advantages such as cost-effectiveness, easy availability, and patient acceptance for procedures like depigmentation [15].

Laser ablation has been recognized as one of the most effective, comfortable, and dependable techniques for gingival depigmentation [29]. However, the main drawback of laser treatment is the equipment cost compared to more affordable treatments [31].

Lasers can be utilized in both contact and non-contact applications. When operating in contact mode, operators can use Nd:YAG and diode lasers, which provide tactile sensations. These lasers should only be applied with delicate and light strokes to prevent any harm to the deeper layers, and it is important to avoid maintaining them at one particular point for too long. Conversely, the Erbium family, CO2, and contemporary super-pulsed diode lasers can all be operated non-contact. While this method necessitates a high level of precision from the operator, it provides a more comfortable experience for patients throughout the surgery by removing the scraping sensation, as explained earlier by Muruppel et al. (2020) [13].

The effectiveness of CO2 and diode lasers was compared in a previous study by Moeintaghavi et al. (2022). The diode laser was considered much more aesthetically appealing at the 6-month follow-up [32]. In addition, when the diode and Er:YAG lasers’ effectiveness in gingival depigmentation was compared by Jnaid Harb et al. (2021), no significant aesthetic differences were observed between the two lasers’ outcomes. However, the diode significantly attenuated pain and enhanced hemostasis [33]. Similar clinical outcomes were obtained by Altayeb et al. (2021) in a different investigation after using Er,Cr:YSGG and diode lasers [1]. According to previous studies, the utilization of diode laser for depigmentation is a tolerable and effective treatment that reduces patient anxiety and produces better results [34‐36]. Nevertheless, specific care should be taken to prevent the risk of gingival fenestration or bone exposure. The CO2, Er:YAG, and Er, Cr:YSGG lasers have been utilized in previous studies in this field; however, the diode laser provides certain benefits, including increased efficacy, shorter treatment times, and improved coagulation [18, 37‐39].

There is not enough research or evidence on the effectiveness of soft tissue trimmers compared to lasers and traditional surgery in reducing discomfort postsurgery and accelerating the wound healing process. Therefore, the present study compared the efficacy of a scalpel, ceramic trimmer bur, and diode laser (980 nm) for gingival depigmentation.

In the current study, a diode laser of 980 nm was used to accomplish laser-assisted gingival depigmentation. Since the diode laser’s approximate wavelength extends from 800 to 1000 nm, it exhibits the highest absorption rate for melanin and the lowest absorption rate for hydroxyapatite in this spectrum [40]. The diode laser is an effective surgical soft tissue laser suited to cutting and coagulating gingival and oral mucosa since it does not impact dental hard tissues. The diode laser’s “hot tip” effect, brought on by heat buildup at the fiber tip, forms a deep coagulation layer in the treated area [41].

The treatment was conducted in contact mode, allowing for good tactile sensation and operating precision [42, 43]. Clinical outcomes demonstrated practical, efficient, and safe ablation of melanin pigmentation using this contact technique. Additionally, achieving complete de-epithelialization necessitates employing the device in contact mode to ensure optimal control of the laser beam without causing harm to nearby teeth and alveolar bone [44].

The Visual Analog Scale was employed in the current study to measure postoperative pain. The present study revealed a statistically significant decrease in the three groups’ median pain scores over time. The laser group reported the least pain at 12-h follow-up, followed by the ceramic bur and scalpel groups. The median pain score was significantly lower in the diode laser group than in the surgical scalpel group but not significantly different from the ceramic bur group. On days 4 and 7, there was no statistically significant difference regarding how each group perceived pain (Table 1).

It was theorized that the more invasive surgical procedures using the scalpel, which result in significant bleeding and surgical incisions that are fully exposed, might be to blame for the higher pain perception associated with them. Since the open wound heals with secondary intention, adding to the postoperative discomfort. Additionally, the increased pain on the tissue surface could be attributed to exposed nerve endings caused by making a deeper incision with a surgical scalpel and the longer procedure time. The coagulation of protein on the wound surface, acting as a biological wound dressing, is why the laser groups experience reduced postoperative pain. Additionally, the laser can seal sensory nerve endings [37, 45]. When using the ceramic trimmer to remove tissue, the bur would need to rotate at a high speed. Through mechanical force and friction, the bur cuts or abrades the tissue when it comes into contact with it. The effectiveness and depth of tissue removal depend on the rotational speed and pressure. It was assumed that the less painful surgical method was using a ceramic trimmer bur maybe because it just removes the epithelium surface’s outermost layer, sparing the lamina propria beneath it, which contains the nerves [46].

The results of the current study are in agreement with the one by Negi et al. (2019), which compared the effectiveness of a soft tissue trimmer and laser for gingival depigmentation and revealed that most laser-treated sites showed minimal to no pain, while patients who underwent bur treatment experienced minimal to moderate pain [15]. In contrast to the results of our study, Goldar et al. (2020) discovered that, although there were no statistically significant differences between the laser and ceramic trimmer groups, subjects who used the laser experienced more discomfort on the first and third postoperative days [10].

Moreover, the outcomes of the current inquiry are in accord with those of Suragimah et al. (2016), who discovered that even though there was no variation between the scalpel and laser techniques on the seventh day, patients who underwent laser treatment initially endured less postoperative pain than those who underwent the scalpel procedure [47].

In the current study, surgical bleeding was compared across all techniques. In contrast to the ceramic bur group and the laser group, the scalpel group’s bleeding median value was statistically significantly more remarkable, without a statistically significant difference between the ceramic bur group and the laser group (Table 2).

The “hot tip” effect brought on by heat buildup at the fiber’s end helps remove the superficial layer of epithelium without bleeding or trauma to the mucosa. Furthermore, the blood vessels surrounding tissue up to a diameter of 0.5 mm were found to be sealed by laser. As a result, a thick coagulation layer forms on the treated surface, causing hemostasis and a reasonably dry surgical area [10]. Similarly, these trimmers comprise mixed ceramics, including zircon dioxide that partially stabilized Yttrium and aluminum ceramic. They secure a fine, delicate incision while the heat buildup produces good hemostasis, resulting in minimal bleeding and almost no risk of necrosis. This may be due to the thermo-coagulation impact of the bur-induced heat [15]. The study’s findings corroborated those of Suragimah et al. (2016), who reported that areas treated with lasers bled significantly less than areas treated with scalpels [47]. These findings are consistent with those of an earlier investigation by Al Mokadem et al. (2023), who found that using a soft tissue trimmer during gingivectomy and gingivoplasty surgeries could be a promising and quick method with minimal postoperative pain. They also found that immediate coagulation while using the soft tissue trimmer reduces intraoperative bleeding and enhances wound healing [48].

Regarding the time taken to complete the procedure, it was found that the laser technique consumed significantly less time than the scalpel and ceramic bur techniques. However, a statistically significant difference was not seen when comparing the ceramic bur and scalpel techniques (Table 3). This might be explained by the lack of bleeding throughout the laser surgical procedure, which was simpler and less technique-sensitive than a scalpel. In contrast, ceramic trimmer burs mechanically cut the pigmented tissues, requiring repeated treatment passes to remove the superficial layers of pigmented tissues with the burs, adding time to the process.

The hydrogen peroxide test was used to assess the degree of epithelialization. In the connective tissue bed underneath the epithelium, catalase reacts with H₂O₂ to release H₂O and O₂, which are detected as bubbling at the healing site [49]. Bubble formation is not clinically apparent when the epithelial barrier is intact, as H₂O₂ cannot reach the connective tissue bed.

The results of the present study showed that on day 4, all groups displayed partial epithelialization; however, on day 7, the scalpel group showed complete epithelialization in 87.5% of the cases, compared to 75% of the cases in all other groups, with no significant difference between any of the groups (p = 0.9) (Table 4).

After depigmentation, the reported time for complete epithelialization varies. In contrast to our findings, Nagpal et al. (2015) found that it took 3 months for gingival depigmentation using a diode laser with 810-nm wavelength to epithelialize completely [50]. A second study was conducted by Jagannathan et al. (2020) utilizing a diode laser with an 810-nm wavelength, and complete epithelialization was also reported 2 weeks after the end of the treatment [17]. The inconsistency in the results between the studies could be attributed to using different laser parameters.

Unlike other research in this area [27, 51, 52], the scalpel and ceramic bur groups had higher median values for gingival healing than the laser group. However, the difference between the groups’ median values did not approach a statistically significant level, and gingival healing was almost complete after 1 week (Table 5). Sharon et al. (2000) and Esen et al. (2004) concluded a 2-week and 6-week duration for postoperative healing following depigmentation with CO2 and cryosurgery, respectively. At the same time, Atsawasuwan et al. (2000) claimed that with the administration of a Nd:YAG laser, full healing was achieved in 1–3 weeks.

The current study’s findings are consistent with a work by Govila et al. (2011) that employed a 940-nm diode laser for gingival depigmentation [53]. A previous study by Suragimah et al. (2016) that found no statistically significant difference in wound healing between scalpel and laser treatments after gingival depigmentation confirms the results of the current investigation [47]. It has been proposed that this impact is caused by reactive oxygen species (ROS) generation when tissues are exposed to laser light [54]. Additionally, photobiomodulation (PBM) might accelerate the healing of laser-treated wounds. Combining LLLT with high-level laser therapy at the target tissue’s boundary explains lasers’ benefits in this application.

In general, evaluation on day 7 for all procedures showed restoration of the gingiva’s normal features without developing scars. Therefore, regardless of the methods employed, the depigmented gingiva healed uneventfully, irrespective of the techniques used.

Images for the current study were taken using the same camera, zoom, and preset chair position to establish uniformity. The distance between the patient and the camera was likewise standardized by putting the camera on top of a tripod.

The effectiveness of the depigmentation treatment was assessed at baseline and after 1 week using DOPI and Takashi indices to give more accurate results. There was no statistically significant difference between any of the other groups before, after, or in the percentage of change (percentage decrease). However, both melanin scores (DOPI and Takashi) within the same group decreased statistically significantly 1 week after treatment (Tables 6 and 7). The outcomes revealed the absence of a statistically significant difference in gingival depigmentation efficacy between any of the groups. Research by Kumar et al. (2013) and Abdullah et al. (2014) support these findings [55, 56].

However, given the short follow-up period of this study and because the outcomes of depigmentation procedures are dependent not only on the level of achieved depigmentation but also on how long it takes for re-pigmentation to develop, these results may not be conclusive, and more studies with a prolonged follow-up duration are recommended.

The surgical scalpel, ceramic trimmer bur, and diode laser 980 nm efficiently removed the gingival pigments, and the clinical outcomes were comparable 1-week postsurgery. A diode laser is a safe and efficient treatment option for gingival hyperpigmentation. However, in comparison to a diode laser, considering that using a soft tissue trimmer is simple and readily available and costs just one-sixtieth of what a laser does, it can be said that it can be utilized as an alternative to a laser in gingival depigmentation procedures.