Gingival depigmentation using Er:YAG laser and scalpel technique: A six-month prospective clinical study

Introduction

The aim of this study was to compare the effects of Er:YAG laser and standard scalpel technique in treatment of gingival hyperpigmentation over a period of 6months, regarding the efficacy of depigmentation and the stability of the results in the follow-up period, hemostasis effect, postoperative pain perception and discomfort, wound healing capacity, patient preference of the techniques, and the level of patient satisfaction after the therapy.

Method and Materials

Study description

This study was a prospective blinded clinical trial with split-mouth design comparing Er:YAG laser and scalpel technique for treatment of gingival hyperpigmentation. A sample size of 20 subjects, with 40 treated sites, 20 in each arm, was sufficient to detect a mean difference of 1 unit on the rating scale between groups in reducing pigmentation assuming a standard deviation (SD) of 0.1 with 80% power and a 5% level of significance. Considering a dropout rate of 10%, the sample size required was 22 (22 per treatment group).

In the beginning, 33 patients who were referred to the Department of Periodontics at Jordan University of Science and Technology, Irbid, Jordan, complaining of unpleasant gingival pigmentation in the labial aspect of the maxilla were invited to participate in the study. After completion of the treatment, a total of 20 patients (12 females and 8 males) were followed up to a period of 6 months (Fig1). The same operator performed all surgical procedures and clinical examination. Randomization and masking were performed by preparing a box with closed envelopes, with equal distribution of the sides to receive both treatment modalities; after opening the envelope, and choosing the sides, the name of the patient was written on the envelope and was closed again until completion of all follow-up appointments. Gingival pigmentation was assessed at the follow-up appointments by direct clinical examination by the same examiner, and assigned scores based on right and left sides without knowing the technique performed on each side. At the end of the follow-up appointments, the patient’s own envelope was opened again and the scores were distributed to both treatment modalities (Er:YAG laser and scalpel) on a different paper form.

Fig1Study design flow chart.

Treatment protocol

All included subjects underwent initial periodontal therapy 2 weeks preoperatively, including supra- and subgingival scaling. Oral hygiene instructions were given to the patients, with chlorhexidine gluconate mouth wash (0.2%; Gargarol, Beit Jala Pharmaceutical) prescribed for 7 days. For the 22 patients included in the study, the two contralateral sites presenting melanin gingival hyperpigmentation in the anterior maxillae from the distal side of the canine to the midline were randomly assigned to receive either Er:YAG laser or scalpel technique for the esthetic treatment of gingival melanin hyperpigmentation.

The treatment time was calculated from the beginning of the surgical procedure and the first laser application, until complete depigmentation was achieved. To standardize the time period measured, a 5-minute period was assigned for the local infiltration anesthesia given to the scalpel site and for the topical anesthesia used on the laser sites.

Hemostasis effect was assessed by visual examination and based on the amount of bleeding encountered during the procedure and the difficulty of performing the procedure. It was assessed on the following scale:

no bleeding, complete homeostasis

isolated bleeding points during surgery (mild)

moderate bleeding, but clear field

All patients were called by their mobile number on the evening of the operation day (day 1), day 2, and day 3 postoperatively, and were asked to mark the level of pain experienced based on the 0 to 10 numeric pain rating scale (visual analog scale), with the left end (0) point marked “no pain” and the right end (10) marked “severe pain.” A mark was placed at the corresponding number to match with the level of pain experienced. Scores were calculated as:

0, no pain

1 to 3, mild pain,

4 to 6, moderate pain

In case the pigmentation extended further distal to the canine, it was removed without measuring the time required for the further procedure. Postoperative oral hygiene instructions were given to the patient, and they were instructed to avoid smoking and eating hot and spicy food for the first 24 hours.

The same operator performed in one visit all treatments. At the end of the procedures, all patients were instructed to use paracetamol 500mg four times a day when needed in case of pain. Patients were also instructed to use chlorhexidine gluconate (0.2%, Gargarol) mouth wash in the first postoperative week. If the patient had gingival pigmentation on the mandibular gingiva, it was depigmented in a later appointment with the preferred method, but was not included in the study.

Er:YAG laser site

For sites treated with laser, benzocaine 20% as topical anesthesia in the form of gel (Ultracare, Ultradent Products) was applied for 5 minutes from the midline distally in the laser site, and an Er:YAG laser device (Doctorsmile Pluser laser, Lambda Scientifica) with a continuous wavelength of 2,940nm was applied at 1W via a sapphire tip (diameter 800 μm; length 12mm) in a fiber-optic handpiece. The procedure was performed with the handpiece at a distance of 5mm from the gingiva in a noncontact mode and from a cervical-apical direction in a brush stroke pattern until the entire area was completely depigmented. The operative site was cooled using 50% air spray and 50% water spray.

Scalpel technique sites

Lignocaine hydrochloride (2%) with 1:100,000 adrenaline (Octocaine 100, Novocol Pharmaceutical) was administered by infiltration of the scalpel-treated area from the midline distally. After a 5-minute period, the anesthesia was checked. Partial dissection or peeling of the affected area was performed using blade no. 15c. If the papilla was pigmented, it was also de-epithelized to avoid a migration effect of the melanocytes. The surgical site was irrigated frequently with normal saline during the procedure, and a gauze pressure pack was given to the patient to control the bleeding if present. No periodontal dressing was placed.

Data management and statistical analysis

The data were coded and entered in a Microsoft Excel sheet, imported and analyzed using SPSS (IBM, v23.0). Mann-Whitney U test was used to check the level of significance between the two study groups regarding the DOPI, HMI, Bleeding Index, chair time, and wound healing index. Within study groups, differences between the three times (baseline, and 3 and 6 months following intervention) were analyzed using Kruskal-Wallis test. Association between patient preference and degree of satisfaction was checked using chi-square test. A P value of ≤.05 was considered significant for all tests.

Results

A total of 20 subjects successfully completed the study period of 6 months and were included in the data analyses. All 20 participants maintained the recall visits at 2and 6 months (Fig2).

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Fig 2 Follow-up of a single case. (a) Preoperative view.

Fig 2 Follow-up of a single case. (b) Immediate postoperative view (R, scalpel; L, laser).

Fig 2 Follow-up of a single case. (c) 1-week postoperative.

Fig 2 Follow-up of a single case. (d) 2-weeks postoperative.

Fig 2 Follow-up of a single case. (e) 1-month postoperative.

Fig 2 Follow-up of a single case. (f) 3-months postoperative.

Fig 2 Follow-up of a single case. (g) 6-months postoperative.

Changes in DOPI

As displayed in Tables1 and 2, no statistical difference was found between both groups at the baseline regarding the DOPI and HMI measurements (P=.752 and 1.000), respectively.

At the 1-week, 2-week, and 1-month appointments, all the sites were free from any pigmentation and the DOPI measurements were 0.00 at all Er:YAG laser and scalpel sites.

At 3 months, 16 patients (80%) had grade 0, and four patients (20%) had grade 1 at the Er:YAG (2,940nm) laser sites. Seventeen patients (85%) had grade 0, and three patients (15%) had grade 1 at the scalpel sites. Both groups showed a positive result regarding the gingival depigmentation treatment without significant difference between them (P=.681).

At 6 months, 14 patients (70%) had grade 0, and 6 patients (30%) had grade 1 at the Er:YAG (2,940nm) laser sites. Sixteen patients (80%) had grade 0, and four patients (20%) had grade 1 at the scalpel sites. No significant difference was found between both treatment modalities at the 6-month appointments (P=.471)

Changes in HMI

At the 1-week, 2-week, and 1-month appointments, all the sites were free from any pigmentation and the HMI measurements were 0 at all Er:YAG laser and scalpel sites.

At 3 months, 16 patients (80%) had grade 0, and four patients (20%) had grade 1 at the Er:YAG (2,940nm) laser sites. Seventeen patients (85%) had grade 0, and three patients (15%) had grade 1 at the scalpel sites. Both groups showed a positive result regarding the gingival depigmentation treatment without significant difference between them (P=.681).

At 6 months, 14 patients (70%) had grade 0, five patients (25%) had grade 1, and one patient had grade 2 (5%) at the Er:YAG (2,940nm) laser sites. Sixteen patients (80%) had grade 0, and four patients (20%) had grade 1 at the scalpel sites. No significant difference was found between both treatment modalities (P=.429).

Total treatment time (chair time)

A longer treatment time was observed in the Er:YAG laser sites (11.9 minutes) than in the scalpel sites (11.2 minutes), but the comparison between groups was not statistically significant (P=.459).

Bleeding during the procedure

The mean scores of Bleeding Index for Er:YAG laser sites and the scalpel sites were 1.05 and 1.80 respectively. There was a statistically significant difference between the groups regarding the Bleeding Index (P<.001).

Pain perception postoperatively

As shown in Table3, the mean scores for pain using a 0 to 10 horizontal numeric scale at days 1, 2, and 3 were 1.75, 1.00, and 0.00 respectively for the Er;YAG laser sites, and were 1.30, 0.75, and 0.00 respectively for the scalpel sites. No significant differences were found between the groups regarding the pain perception at the first 3 days after treatment (P>.05). Only two patients reported using analgesics after treatment.

Patient preference

From the total of 20 patients, 11 (55%) patients preferred the scalpel technique, and nine (45%) gave first preference to the Er:YAG laser technique. The comparison was not statistically significant (P=.40) (Fig3).

Fig 3Percentage of patient preference for the two study techniques.

Wound healing and degree of epithelialization

At the 1-week follow up (Fig4), for the Er:YAG laser sites, only two patients (10%) showed complete epithelialization and 18 patients (90%) showed incomplete epithelialization. For the scalpel sites, none of the patients showed complete epithelialization, whereas two patients (10%) showed small unhealed ulcers. The difference between the groups at the 1-week follow-up was statistically significant (P=.048),

Fig 4Percentage of patients showing different healing status at 1 week postoperatively for the two study techniques.

At the 2-week follow-up, all patients (100%) showed complete epithelialization at the Er:YAG laser sites, while in the scalpel sites 18 patients (90%) showed complete epithelialization, and two patients (10%) showed incomplete epithelialization. However, the comparison was not statistically significant (P=.152) (Fig5).