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ORIGINAL ARTICLE
Year : 2016  |  Volume : 10  |  Issue : 1  |  Page : 2-9

Comparative evaluation of two surgical techniques using conventional scalpel method and diode laser for treatment outcome of depigmentation: 6 months follow-up study


1 ECHS, Polyclinic, Type-C, Thiruvanammalai, Tamil Nadu, India
2 Department of Periodontics, G Pulla Reddy Dental College, Kurnool, Andhra Pradesh, India
3 Department of Periodontics, Ragas Dental College, Chennai, Tamil Nadu, India

Date of Web Publication23-Jun-2016

Correspondence Address:
N Rajesh
Department of Periodontology and Implantology, G. Pulla Reddy Dental College, Kurnool, Andhra Pradesh
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0976-2868.184600

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  Abstract 

Background: Various surgical techniques can be done for depigmentation but recurrence is the limiting factor for many surgical procedures, and the aim of the present study was to evaluate quantitatively the rate of repigmentation postoperatively after using scalpel and diode lasers for depigmentation. Materials and Methods: A total of 20 systemically healthy patients of 18 males and two females, within the age group of 18-40 years with an esthetic complaint of hyperpigmented gingiva were enrolled in this study. The patients were briefed about the surgical procedure and obtained the informed consent; they were randomly divided into two groups. Group A: 10 patients - depigmentation with scalpel technique. Group B: 10 patients - depigmentation with diode lasers (Biolase; ) and followed for 6 months. Results: The results of this study had shown that there is a statistically significant difference in the pre- and post-operative values in scalpel surgical technique with a (P = 0.005), and there is no statistically significant (P = 0.20) difference in the diode laser technique. Statistical Analysis Used: Wilcoxon Signed rank test and Mann-Whitney test. Conclusion: By using diode lasers, the rate of repigmentation is higher than scalpel method; however, it has been documented that there is minimal postoperative bleeding, pain, wound healing, discomfort, and ease of the procedure with diode laser and finally, each technique has its own advantages and disadvantages.

Keywords: Depigmentation, diode laser, repigmentation, scalpel technique


How to cite this article:
Sagar G, Rajesh N, Kumar T, Reddy K K, Shankar B S, Sandeep V. Comparative evaluation of two surgical techniques using conventional scalpel method and diode laser for treatment outcome of depigmentation: 6 months follow-up study. J Dent Lasers 2016;10:2-9

How to cite this URL:
Sagar G, Rajesh N, Kumar T, Reddy K K, Shankar B S, Sandeep V. Comparative evaluation of two surgical techniques using conventional scalpel method and diode laser for treatment outcome of depigmentation: 6 months follow-up study. J Dent Lasers [serial online] 2016 [cited 2024 Mar 28];10:2-9. Available from: http://www.jdentlasers.org/text.asp?2016/10/1/2/184600


  Introduction Top


Esthetic dentistry plays an important role in the society, and clinicians have to face the challenge of achieving acceptable gingival esthetics, along with addressing biological and functional problems. Gingival hyperpigmentation is one of the esthetic problems and requires removal of gingival melanin pigmentation by various methods such as gingivectomy, gingivectomy with free gingival autografts, electrosurgery, cryosurgery, application of chemical agents such as 90% phenol and 95% alcohol, abrasion with diamond bur, neodymium-doped yttrium aluminum garnet (Nd:YAG) laser, semiconductor diode laser, and CO2 laser. [1],[2] These techniques have shown variable results, and each technique has its own advantages and disadvantages. Lasers have been used in dentistry; since the beginning of the 1980s, semiconductor diode laser has been used for gingivectomy, frenectomy, incisional and excisional biopsy, soft tissue tuberosity reduction, operculum removal, coagulation of graft donor site, and exposure of soft tissue covering osseointegrated implants. Laser ablation for gingival depigmentation has been recognized as one of the most effective, pleasant, and reliable techniques. [3] 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 into light energy; this 810 nm diode laser has energy and wavelength characteristics that specially target the soft tissues. It has an affinity for hemoglobin and melanin; therefore it is more efficient and better equipped to address deeper soft tissue problems.

Data regarding on depigmentation and repigmentation following surgical removal of pigmented gingiva in human are extremely limited. In order to find a better approach for gingival depigmentation, a comparative evaluation of two surgical techniques using conventional scalpel method and 810 nm wavelength (Biolase TM 4 Cromwell Irvine, CA imported by Biolase Technology India Pvt. Ltd. Andheri (W), Mumbai) diode laser was undertaken in this study.


  Materials and Methods Top


A total of 20 systemically healthy patients, within the age group of 18-40 years with an esthetic complaint of hyperpigmented gingiva, were enrolled in this study from the Outpatient Department of Periodontics of Ragas Dental College, Chennai. The sample population had 18 males and two females. The patients were briefed about the depigmentation procedure. After obtaining the informed consent, they were randomly divided into two groups.

  • Group A - 10 patients: Depigmentation with Scalpel technique
  • Group B - 10 patients: Depigmentation with diode lasers (Biolase® ).


The following patients were included in the study patients of age group 18-40 years, patients with physiological melanotic pigmented gingiva in relation to maxillary anterior region 13-23, patient with esthetic concern, patient with thick gingival phenotype and healthy gingiva, and patient with good oral hygiene.

The following patients were excluded in the study patient under medication, chronic smokers, systemically compromised patients, pathological pigmentation other than physiological pigmentation, pregnant and lactating women, patients with history of periodontal treatment for past 6 months, patient with history of postsurgical keloid.

Methodology

The patients who consented for the study underwent thorough oral prophylaxis procedure, and oral hygienic instructions were given.

Depigmentation with scalpel technique

Under local anesthesia with 1:80,000 adrenaline, pigmented epithelium was excised with split thickness flap using no 15 blade. Care is taken to include the epithelium at the tip of interdental papilla and the mucogingival junction on the other end without disturbing the marginal gingiva. Periodontal pack is placed, and postoperative instructions were given [Figure 1],[Figure 2],[Figure 3],[Figure 4],[Figure 5],[Figure 6] and [Figure 7].
Figure 1: Depigmentation with conventional scalpel method, preoperative

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Figure 2: Depigmentation with conventional scalpel method, postoperative

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Figure 3: Depigmentation with conventional scalpel method, 10 days postoperative

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Figure 4: Depigmentation with conventional scalpel method, 30 days postoperative

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Figure 5: Depigmentation with conventional scalpel method, 60 days postoperative

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Figure 6: Depigmentation with conventional scalpel method, 90 days postoperative

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Figure 7: Depigmentation with conventional scalpel method, 180 days postoperative

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Depigmentation with diode laser technique

Depigmentation procedure was done with topical application of local anesthetic gel. A diode laser (Biolase® ) with settings of 810 nm 60 J/s in pulsed mode was delivered through a 400 μ fiberoptic tip. The pigmented gingival epithelium was ablated using direct contact mode in painting strokes. Care was taken to include the epithelium at the tip of interdental papilla and the mucogingival junction on the other end without disturbing the marginal gingiva. Postoperative instructions were given. Usual protocols were maintained to the patient as well as operator during laser application.

Postsurgical care

Patients were instructed to continue with good oral hygiene and avoid trauma around the surgical site. Patients were prescribed with paracetamol 500 mg TD to be taken in case of pain only and 0.2% chlorhexidine digluconate rinse twice daily for 2 weeks. Periodontal dressing was removed at the end of 10 days and also was put on gentle and soft brushing after pack removal for a week. Patients were recalled at the end of 10 days, 30 days, 60 days, 90 days, and 180 days postoperatively for monitoring and reinforcement of oral hygiene.

The intensity of pigmentation was assessed using image analysis software (National Health Institute). After isolating the gingiva with cotton rolls, digitalized images were recorded with NIKON-D 100 digital SLR camera and ring flash with the following settings at a predetermined distance of 37 cm as indicated by the camera. Pre- and post-operative photographs were taken at 10 days, 30 days, 60 days, 90 days, and 180 days interval [Figure 8],[Figure 9],[Figure 10],[Figure 11] and [Figure 12].
Figure 8: Depigmentation with semiconductor diode laser, preoperative

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Figure 9: Depigmentation with semiconductor diode laser, 10 days postoperative

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Figure 10: Depigmentation with semiconductor diode laser, 30 days postoperative

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Figure 11: Depigmentation with semiconductor diode laser, 60 days postoperative

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Figure 12: Depigmentation with semiconductor diode laser, 180 days postoperative

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  • Light intensity - Auto sensory and auto light intensity adjusted
  • Shutter speed - 1/250
  • Focal length - 37 cm
  • Depth of focus - 1:2.8 D
  • Lens - macro lens (AF macro Nikkor lens 105 mm)
  • Aperture ring - 36 diaphragm.


Image analysis

The digitalized images were assessed for the intensity at three randomly selected sites from the image. The image was scaled using Adobe Photoshop CS7 (Adobe Systems Incorporated 345 Park Avenue San Jose, CA) once the images were scaled down to 6 MP resolution; the intensity was measured using Image J 1.42q, U.S. National Institutes of Health, Bethesda, Maryland, USA (National Institutes of Health).


  Results Top


Results of this study show that there is an statistically significant difference in the pre- and post-operative values in scalpel surgical technique with a P = 0.005, and there is no statistically significant (P = 0.20) difference in the diode laser technique.

[Table 1] represents the comparison of total surface area of intensity of pigmentation pre- and post-operatively in the laser group; it shows the P = 0.20 which is statistically insignificant.
Table 1: Comparison of total surface area at preoperative versus postoperative in laser group

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[Table 2] represents the percentage of repigmentation at various time intervals with that of the baseline value of laser group; it shows there is no statistically significant change in the intensity of pigmentation pre- and post-operatively.
Table 2: Comparison of rate of repigmentation at various times with that of the baseline value for laser group

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[Table 3] represents the comparison of intensity of pigmentation of total surface area pre- and post-operatively in scalpel group; it shows the P = 0.005 which is statistically significant.
Table 3: Comparison of total surface area at preoperative versus postoperative in scalpel group

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[Table 4] represents the comparison of repigmentation at various time intervals with that of the baseline values for scalpel group; it represents the P = 0.005 at all the time intervals within 6-month which is statistically significant.
Table 4: Comparison of rate of repigmentation at various times with that of the baseline value for scalpel group

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[Table 5] represents the percentage of repigmentation at various time intervals between laser group and scalpel group which represents there is a statistically significant difference in the rate of repigmentation between scalpel and laser group.
Table 5: Comparison of rate of repigmentation at various time intervals between the laser and scalpel groups

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In Graph 1, the intensity of pigmentation in the scalpel group was more in preoperatively and was increased steeply after depigmentation procedure then gradually decreased over time period of 6 months; whereas in laser group, the intensity of pigmentation was low in preoperatively and was increased slightly after depigmentation procedure then gradually decreased at various time intervals.

Graph 2 represents the comparison of percentage of repigmentation between scalpel and laser depigmentation technique, in which the blue bar represent the preoperative values of the intensity of pigmentation and green bar represents the postoperative value of the intensity of pigmentation.

[Table 6] shows that there is a statistical significance in the percentage of intensity of pigmentation pre- and post-operatively at various time intervals in the scalpel group whereas there is no statistical significance in the laser group at various time intervals.
Table 6: Comparison of total surface area between the laser and scalpel groups at various time intervals

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Statistical analysis

All clinical data of gingival pigmentation of 10 patients treated by scalpel method and 10 patients with laser application were analyzed by using Wilcoxon signed rank test for significance of changes.


  Discussion Top


Esthetics plays an important role in patients' psychological and social well-being. Gingival health and appearance are essential components for a pleasant and confident smile. Gingiva is the most frequently pigmented intraoral tissue. [4] Melanin is a nonhemoglobin derived pigment formed by the cells called melanocytes, which are dendritic cells of neural ectodermal origin located in the basal and spinous layers of the gingival epithelium. Melanin granules are phagocytosed and contained within other cells of epithelium and connective tissue called melanophages or melanophores. [5] It is generally accepted that pigmented areas are present only when melanin granules synthesized by melanocytes are transferred to keratinocytes. This close relationship between melanocyte and keratinocytes was named by  Fitzpatrick and Breathnach as the epidermal-melanin Unit. [6]

Oral melanin pigmentation is well-documented in literature and is considered to be multifactorial, whether physiological or pathological and can be caused by a variety of local and systemic factors including genetic, tobacco use, prolonged administration of certain drugs, especially antimalarial agents, and tricyclic antidepressants. [7] Gingival hyperpigmentation is seen as a genetic trait in some population and termed as physiologic or racial gingival pigmentation. [8] It has been suggested that although pigmentation under normal conditions is genetically determined, its distribution in the mouth may be the result of secondary influences and environmental factors. High levels of oral pigmentation are normally observed in individuals of African, East-Asian, or Hispanic ethnicity. [9] Earlier studies have shown that no significant difference exists in the density of distribution of melanocytes among light-skinned, dark-skinned, and black individuals. However, melanocytes of dark-skinned and black individuals are uniformly highly reactive than in light-skinned individuals. [10] Individuals may become more conscious of black or dark patches of pigmentation and request their removal. [5] Demand for depigmentation is usually made for esthetic reasons, particularly in patients having a gummy smile. Elimination of these melanotic areas is done through surgery or lasers. [11],[12] Cryosurgery through use of a gas expansion system, [13] bur abrasion, scraping electrocautery, [14] and chemicals have been reported by many authors. [15],[16],[17] Each technique has its own advantages and disadvantages. Lasers were first introduced in 1960 by Maiman and were brought into general practice by Dr. William and Terry Myers although CO 2 lasers are used for depigmentation procedure, they can damage tooth structure, and the delivery system is very cumbersome. Diode is an excellent soft tissue laser, and it is indicated for cutting and coagulating gingival tissue; [4] thus, we decided to use diode lasers. Wavelengths of diode laser are highly absorbed by pigmented tissue. The use of semiconductor diode laser for depigmentation procedure was introduced by Yousuf et al. [2] The semiconductor diode laser which is made up of aluminum, garnet, and arsenide diode emitting in continuous mode and operated in a contact method using a flexible fiberoptic delivery system. Laser light at 810 nm is poorly absorbed by water but highly absorbed in hemoglobin and other pigments. Since the diode laser basically does not interact with dental hard tissues, the diode laser is an excellent soft tissue surgical laser, indicated for cutting and coagulating gingival and oral mucosa. The diode laser exhibits thermal effects using the "hot-tip" effect caused by heat accumulation at the end of the fiber and produces a relatively thick coagulation layer on the treated surface. The usage is quite similar to electrocauterization. As the tissue penetration of a diode lasers is minimal, it does not produce any deleterious effect on the root surface. The usual mechanism of diode laser that lead to ablation or decomposition of biological materials is photochemical, thermal, or plasma mediated. Thermal ablation means that the energy delivered by the laser interacts with irradiated material by an absorption process, yielding a temperature rise. [18] As the temperature increases at the surgical site, the soft tissue is subjected to warming (37-60°C), protein denaturation, and coagulation (>60°C). The rapid rise in intracellular temperature and pressure leads to cellular rupture as well as release of vapors and cellular debris termed the laser plume; it creates locally sterile condition, resulting in a reduction of bacteremia. The rapid wound healing after using lasers may be related to the photobiomodulation (PBM). PBM or low-level laser therapy (LLLT) is the application of electromagnetic energy in the red and near-infrared region to damaged or diseased tissue. LLLT may occur simultaneously with the high-level laser therapy at the periphery of the target tissue, therefore, explaining some of the advantages of lasers in high-level laser therapy.

The healing period of scalpel wounds is shorter than with diode laser. [19] However, scalpel surgery causes unpleasant bleeding during and after the operation, and it is necessary to cover the exposed lamina propria with a periodontal pack for 10 days. However, the diode laser causes minimal damage to the periosteum and bone under the gingiva being treated, and it has the unique property of being able to remove a thin layer of epithelium, a sterile inflammatory reaction occurs after lasering. [20] Blood vessels in the surrounding tissue up to a diameter of 0.5 mm are sealed thus, the primary advantage of hemostasis and a relatively dry operating field. Clinical parameters such as bleeding, wound healing, gingival color, pain, and difficulty of the procedure were evaluated immediately and 10 days, 30 days, 60 days, 90 days, and 180 days postoperatively.

All the depigmentation techniques have shown considerable amount of recurrence rates even at time intervals <5 month. Studies have reported repigmentation in 50% of cases after split-thickness excision in 24 and 55 days. [21] Studies have shown recurrence of gingival hyperpigmentation after gingivectomy in 6 of 8 patients in follow-up period of 33-120 days. [16] Studies have reported no recurrence after 11-30 months in four patients after Nd: YAG laser depigmentation. [17] However, some studies have shown no repigmentation occurring in any of their patients treated with Er: YAG laser after 6 months. [22] To prevent the recurrence, the gingival tissue should be cleared of melanin entirely including free gingiva and interdental papilla since repigmentation starts as a result of migrating melanocytes from free gingiva. [20] Adequate tissue removal may not be possible at the gingival margins and interdental papillary region due to close proximity of the adjacent teeth which may be damaged by the laser beam, this limitation may result in incomplete vaporization of the pigment in such delicate areas, which tend to promote repigmentation.


  Conclusion Top


Elimination of the melanotic areas can be achieved by various surgical methods such as gingivectomy, gingivectomy with free gingival autografts, electrosurgery, cryosurgery, application of chemical agents such as 90% phenol and 95% alcohol, abrasion with diamond bur, Nd: YAG laser, semiconductor diode laser, and CO 2 laser. Each technique has its own advantages and disadvantages. By using diode lasers, it has been documented that there is minimal postoperative bleeding, pain, wound healing, discomfort, and ease of the procedure. However, drawback of this study is less number of subjects, shorter follow-up period, and there is no histological and histochemical assessment for the activity of melanocytes.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

 
  References Top

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Esen E, Haytac MC, Oz IA, Erdogan O, Karsli ED. Gingival melanin pigmentation and its treatment with the CO2 laser. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2004;98:522-7.  Back to cited text no. 1
    
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    Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9], [Figure 10], [Figure 11], [Figure 12]
 
 
    Tables

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6]


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