Effect of diode laser as an adjunct to open flap debridement in treatment of periodontitis – A randomized clinical trial

Abstract

Background:

The goals of periodontal therapy are to prevent the disease, arrest the disease progression, and regeneration of lost periodontium. Diode laser gained popularity in periodontal practice with a wide range of potential benefits.

Aim:

This study aims to evaluate and compare the clinical effects of laser-assisted open flap debridement (OFD) versus conventional OFD for the periodontitis treatment.

Materials and Methods:

A split-mouth, randomized clinical trial was conducted on fifteen participants with periodontitis having probing pocket depths (PPD) ≥5 mm. A total of 30 sites, two sites in each patient, were randomly divided into two groups. Group A received conventional OFD, and Group B received laser-assisted OFD. The assessment of PPD, relative attachment level (RAL), modified sulcular bleeding index (mSBI) was done at baseline, 3 months, and 6 months. Wound healing index (WHI) was assessed at 3^rd and 7^th day postsurgery, patient response to pain using visual analog scale (VAS) was assessed immediately, 1 day, and 1 week after surgery.

Results:

The results revealed a significant reduction in PPD, mSBI, and gain in RAL within the groups from baseline to 3 months and 6 months. Intergroup comparison showed a significant difference in PPD, RAL, mSBI, WHI and VAS scores.

Conclusions:

The use of 980 nm diode laser provided additional benefits over conventional flap therapy.

INTRODUCTION

Periodontitis is an opportunistic infection caused by an imbalance in the virulence factors of pathogenic microorganisms and host defense mechanisms, resulting in an immune-inflammatory response that can cause destruction of the periodontal ligament, alveolar bone with pocket formation and recession.[1]

The purpose of periodontal therapy is to reduce or eliminate the subgingival microorganisms associated with periodontal disease, regenerate the lost tissues, and to maintain periodontal health.

Complete mechanical debridement considered to be the “gold standard” treatment of periodontitis, still does not remove the microorganisms in the wall of the pocket, nor complete resection of the diseased tissues possible.[2]

The retained periodontopathogenic bacteria can penetrate and persist in the epithelial cells of the soft tissue and outer gingiva, leading to recolonization and reinfection.[3]

Various procedures using ultrasonic scalers, locally delivered agents such as antimicrobials, anti-inflammatory agents, and host modulating agents have been evaluated to enhance the treatment outcomes of periodontitis with varying degrees of success. Regardless of the treatment method, pain and discomfort are commonly associated with surgical therapy.

In recent years, the use of lasers adjunct to conventional mechanical procedures commonly employed in the treatment of periodontal diseases. Adequate sterilization, hemostasis, and less postoperative pain have been found in surgical procedures performed with diode laser compared to conventional surgical techniques.

Diode laser has a wavelength of 810 nm or 910–980 nm, mainly target the diseased soft tissues without interacting with dental hard tissues.

It has been suggested that during irradiation, a part of laser energy scatters and penetrates into periodontal pockets, which then stimulate the cells of surrounding tissue, resulting in cell proliferation, a reduction in inflammatory conditions, improvement in periodontal tissue attachment and possible reduction of postoperative pain.[4]

Laser therapy adjunct to nonsurgical treatment was demonstrated to remove the diseased pocket lining epithelium, target the microorganisms (antibacterial effect), hemostasis, delayed epithelial migration, enhance periodontal wound healing.[5] In vitro studies have shown that lasers enhance the synthesis of collagen and procollagen as well as to stimulate and increase the proliferation rate of fibroblasts.[6]

However, the effect of lasers on periodontal treatment is unclear with insufficient data.[7]

The aim of this study is to compare and evaluate the adjunctive benefits of a diode laser to conventional surgical debridement in the treatment of periodontitis, testing the hypothesis that adjunctive use of diode laser can improve outcomes of surgical periodontal therapy.

Objectives

1. Primary outcome: To compare the clinical parameters with the adjunctive use of a diode laser to conventional flap surgery in patients with periodontitis

2. Secondary outcome: To compare patients response (postoperative pain) following open flap debridement (OFD) with and without adjunctive use of diode laser in patients with periodontitis.

SUBJECTS AND METHODS

This monocentric, triple-blind, split-mouth randomized clinical trial was conducted in the Department of Periodontology at Narayana Dental College and Hospital to evaluate the effect of diode laser as an adjunct to OFD in treatment of periodontitis. This study was per the Helsinki declaration of 1975 revised in 2013 and approved by the Institutional Ethical Committee.

The inclusion criteria of the study were as follows (i) Individuals aged 25–60 years; (ii) Patients requiring flap surgery for at least two sextants in the mouth with a probing pocket depth (PPD) >5 mm; (iii) Patients who are systemically healthy; (iv) Patients who had given written informed consent. Exclusion criteria were: (i) Patients with a history of antibiotic therapy within 6 months; (ii) Pregnancy, lactating women and smokers; (iii) Patients with systemic diseases; (iv) Patients who are deemed to be uncooperative; and (v) Patients with poor oral hygiene

Power analysis performed with a 95% confidence interval, and with a margin of error 5%, the sample size was determined.

Sources of data

Fifteen patients with untreated periodontitis were recruited from the Department of Periodontology, Narayana Dental College and Hospital based on inclusion and exclusion criteria. All the individuals were informed regarding the nature and design of the study, along with written informed consent for their participation before the commencement of the study.

Before surgery, all participants received Phase I therapy consisting of oral hygiene instructions, scaling, and root planing. Four weeks after Phase I therapy, periodontal pockets are measured to confirm suitable sites for OFD. An acrylic stent was prepared to standardize the measurements of clinical parameters at different time intervals. One site from each sextant (2 sites in each patient) was selected and randomly allocated into two groups using a computer-generated random table [Figure 1].

Figure 1.

Consort flow chart of the study

1. Group A (Control group) - Conventional OFD alone

2. Group B (Test group) – Laser-assisted OFD (LA-OFD).

Clinical parameters assessed were: PPD, modified sulcular bleeding index (mSBI),[8] clinical attachment level (CAL)/relative attachment level (RAL), wound healing index (WHI),[9] Visual Analogue Scale (VAS). PPD, mSBI, RAL were assessed at baseline, 3 months, and 6 months after surgery; WHI assessed at 3^rd and 7^th day postsurgery; VAS scores were assessed immediately after surgery, 1^st day and 7^th day postsurgery.

Surgical procedure

After administering local anesthesia (2% lignocaine), surgeries were performed under aseptic conditions by a single operator. In both the sites, OFD was performed first by giving sulcular and interdental incisions, and a full-thickness flap was reflected, and thorough debridement was done. In the test site, a diode laser with a power setting of 2w and wavelength of 980 nm in a continuous mode was used. The inner aspect of the flap was lased by horizontal overlapping strokes from margin to the bottom of the labial/buccal and lingual/palatal flaps using 320 μm diameter laser tip [Figure 2]. Care was taken to prevent laser contact with the root surface and alveolar bone by focusing the laser beam 45° towards the flap. Char layer which was formed after lasing the flap was removed with moist gauze. Control sites received a sham application of diode laser. Flaps were approximated using 3-0 black silk sutures by a simple interrupted suturing technique. Routine postoperative instructions were given along with antibiotics and analgesics. Analgesics were instructed to take only if they experience pain. For 1 week after surgery, all the participants were reinforced and advised to maintain uniform plaque control measures. Sutures were removed on the 7^th day and evaluated sites for any signs of delayed healing, flap necrosis, infection, and scar formation. Besides, patients were asked regarding the experience of postoperative pain, swelling, and bleeding.

Figure 2.

In the test site, after flap elevation, complete debridement was done and inner side of the flap is lased with 980 nm diode laser

RESULTS

The demographic details of the study participants are shown in [Table 1], 15 participants of which 10 were male and 5 were female with a mean age of 38.9.

Table 1.

Demographic data

Characteristic	Participants
n	15
Mean age (SD)	38.9 (7.56)
Minimum age	26.0
Maximum age	50.0
Male frequency (%)	10 (66.7)
Female frequency (%)	5 (33.3)

n - Total number of patients; SD - Standard deviation

[Table 2] shows the intragroup comparison of PPD, RAL, and mSBI in Group A and B. In Group A, PPD, RAL, and mSBI from baseline to 3 months and baseline to 6 months showed a statistical significant difference, but there was no statistically significant difference observed from 3 months to 6 months. Whereas in Group B, PPD and RAL showed significant differences from baseline to 3 months, baseline to 6 months and from 3 months to 6 months. The mean difference of mSBI from baseline to 3 months and baseline to 6 months showed significant difference, but there was no significant difference observed from 3 months to 6 months.

Table 2.

Comparison of probing pocket depth, relative attachment level, modified sulcular bleeding index in each study group at baseline, 3 months and 6 months

Group	n	Mean difference	95% CI		t	df	P
			Lower	Upper
A
PPD
Baseline-3 months	15	1.80	1.32	2.27	8.09	14	<0.001*
Baseline-6 months	15	1.80	1.07	2.53	5.28	14	<0.001*
3-6 months	15	0.01	−0.51	0.51	0.00	14	1.00
RAL
Baseline-3 months	15	1.80	1.32	2.27	8.09	14	<0.001*
Baseline-6 months	15	1.80	1.07	2.53	5.28	14	<0.001*
3-6 months	15	0.01	−0.51	0.51	0.00	14	1.00
mSBI
Baseline-3 months	15	0.60	0.31	0.88	4.58	14	<0.001*
Baseline-6 months	15	0.40	0.04	0.75	2.45	14	0.028*
3-6 months	15	−0.20	−0.57	0.17	−1.15	14	0.271
B
PPD
Baseline-3 months	15	2.33	1.93	2.73	12.4	14	<0.001*
Baseline-6 months	15	3.00	2.33	3.66	9.72	14	<0.001*
3-6 months	15	0.66	0.16	1.16	2.87	14	0.012*
RAL
Baseline-3 months	15	2.33	1.93	2.73	12.4	14	<0.001*
Baseline-6 months	15	3.00	2.33	3.66	9.72	14	<0.001*
3-6 months	15	0.66	0.16	1.16	2.87	14	0.012*
mSBI
Baseline-3 months	15	0.80	0.57	1.02	7.48	14	<0.001*
Baseline-6 months	15	0.86	0.51	1.22	5.24	14	<0.001*
3-6 months	15	0.06	−0.26	0.39	0.43	14	0.67

^*P<0.05 statistically significant, P>0.05 NS. Paired t-test. Group A (Control group) - Conventional open flap debridement alone; Group B (Test group) - Laser-assisted open flap debridement. n - Total number of patients; df - Degrees of freedom; t - Student t-test; PPD - Probing pocket depth; RAL - Relative attachment level; mSBI - Modified sulcular bleeding index; NS - Nonsignificant; CI - Confidence interval; P - Probability

Comparison of clinical parameters (PPD, RAL, mSBI, WHI, VAS) between the groups was shown in [Table 3]. There was a statistically significant difference in PPD, RAL and mSBI observed between Group A and B at 6 months, but there was no significant differences at baseline and 3 months. WHI showed a significant difference between Group A and B at 3^rd and 7^th day postsurgery, and VAS assessing pain showed a significant difference between groups on the day of surgery, one and 7^th day postsurgery.

Table 3.

Comparison of probing pocket depth, relative attachment level, modified sulcular bleeding index, wound healing index and visual analogue scale scores between the study groups at different time intervals

Group	n	Mean	SD	Mean difference	95% CI		t	df	P
					Lower	Upper
PPD
Baseline
A	15	7.00	1.51	−0.40	−1.14	0.34	−1.14	14	0.271
B	15	7.40	1.76
3 months
A	15	5.20	1.14	0.14	−0.52	0.79	0.45	14	0.670
B	15	5.06	1.33
6 months
A	15	5.20	0.67	0.80	0.27	1.32	3.29	14	0.005*
B	15	4.40	0.91
RAL
Baseline
A	15	9.26	1.53	−0.26	−0.94	0.41	−0.84	14	0.413
B	15	9.53	1.72
3 months
A	15	7.46	1.18	0.26	−0.30	0.83	1.00	14	0.334
B	15	7.20	1.26
6 months
A	15	7.46	0.83	0.93	0.44	1.42	4.09	14	0.001*
B	15	6.53	0.83
mSBI
Baseline
A	15	1.40	0.63	0.00	−0.29	0.29	0.00	14	1.000
B	15	1.40	0.63
3 months
A	15	0.80	0.67	0.20	−0.11	0.51	1.38	14	0.189
B	15	0.60	0.63
6 months
A	15	1.00	0.37	0.46	0.18	0.75	3.50	14	0.004*
B	15	0.53	0.51
WHI
Day 3
A	15	3.13	0.35	−0.73	−1.06	0.40	−4.78	14	<0.001*
B	15	3.87	0.35
Day 7
A	15	4.60	0.50	−0.33	−0.60	0.06	−2.64	14	0.019*
B	15	4.93	0.25
VAS
Day 0
A	15	6.47	1.06	1.53	0.91	2.15	5.27	14	<0.001*
B	15	4.93	1.22
Day 1
A	15	5.93	1.16	1.33	0.68	1.98	4.39	14	<0.001*
B	15	4.60	1.12
Day 7
A	15	2.87	1.51	1.06	0.32	1.80	3.09	14	0.008*
B	15	1.80	1.01

^*P<0.05 statistically significant, P>0.05 NS. Independent sample t-test. Group A (Control group) - Conventional open flap debridement alone; Group B (Test group) - Laser-assisted open flap debridement. n - Total number of patients; SD - Standard deviation; df - Degrees of freedom; t - Student t-test; PPD - Probing pocket depth; RAL - Relative attachment level; mSBI - Modified sulcular bleeding index; WHI - Wound healing index; VAS - Visual analogue scale; CI - Confidence interval; NS - Nonsignificant; P - Probability

DISCUSSION

The present study compared the clinical parameters, patient response with the adjunctive use of diode laser to conventional flap surgery in patients with periodontitis.

A randomized, controlled, parallel-arm, split-mouth, triple masked, monocentric trial was undertaken to evaluate the adjunctive benefits of a diode laser to conventional mechanical debridement in the treatment of periodontitis.

Fifteen participants were recruited, two sites in each participant (bilateral/contralateral), i.e., a total of 30 sites were selected and included in the study. The two sites in each patient were randomly allocated into control and test groups based on a computer-generated random table.

All the clinical parameters (PPD, RAL, mSBI) showed no significant difference at baseline. Thus, the obtained results are considered as a direct effect of the intervention done.

Probing the depth of the pocket is an essential factor affecting the long-term stability of the results, and CAL/RAL being the gold standard for evaluating the success of periodontal therapy was considered as the primary outcome measurement. In addition, mSBI, WHI were assessed to evaluate the gingival condition and healing after surgery. As it is important to consider the patient's comfort, we evaluated pain on VAS in this study.

Intragroup analysis in the present study showed a statistically significant reduction of PPD, mSBI and gain in RAL from baseline to 3 months and 6 months posttreatment, in the sites treated with OFD alone (Group A) and LA-OFD (Group B).

Results obtained in this study with OFD alone, i.e., reduction in values of clinical parameters PPD, mSBI, and gain in RAL, from baseline to 3 months and 6 months is in accordance with the earlier studies.[10,11,12] This could be due to the elimination of local factors (plaque and calculus) and pocket lining thereby reduction of overall inflammation.

Clinical outcomes of sites treated with LA-OFD, showed a significant reduction in values of PPD, mSBI, and gain in RAL at 3 months and 6 months compared to baseline, and also significance was observed from 3 months to 6 months.

In intergroup analysis, LA-OFD showed more reduction in PPD compared with OFD alone group at 6 months, and it was statistically significant (P = 0.005), whereas no significance was observed at 3 months. This more significant decrease in PPD in LA-OFD group could be due to increased levels of anti-inflammatory cytokines and enhanced microcirculation by laser irradiation.[13]

On comparison of mean change in RAL between the two groups, the LA-OFD group showed more gain in RAL compared with OFD alone group at 6 months, and it was statistically significant (P = 0.001). In addition to curettes, laser therapy assists in complete removal of the epithelium, suggesting the formation of new connective tissue attachment. Laser-induced thermal necrosis of wound margin seals small vasculature, lymphatics and blocks release of chemical mediators thereby delays the epithelial migration.[14]

In the present study, the LA-OFD group showed a significant reduction in bleeding on probing compared with OFD alone group at 6 months. These findings correlate well with the results obtained from the study done by Aena et al.[15]

In our study, the LA-OFD group showed clinically acceptable values of PPD, RAL, mSBI than OFD alone group, and the improvement was sustained for 6 months. These results are in accordance with study.[16]

However, in contrast with few studies, reported that there are no additional benefits on clinical parameters using diode laser compared to conventional mechanical debridement in the treatment of periodontitis.[17,18,19]

On comparison of mean change in the WHI between the two groups, LA-OFD showed significant improvement in wound healing at 3^rd and 7^th day postsurgery compared to OFD alone group. This could be due to less degradation of collagen after laser irradiation, described in terms of inhibition of plasminogen activator plasmin proteolytic system using lasers.[20]

Kreisler et al.[21]. reported that sites treated with 809 nm laser showed higher fibroblast proliferation and increased production of basic fibroblast growth factor.

Saygun et al.[22] have shown in their study that laser irradiation increases basic fibroblast growth factor (bFGF) release from gingival fibroblasts. “bFGF” is a chemoattractant for fibroblasts and endothelial cells and a potent mitogen which stimulates an angiogenic response in the wound and in epithelial cells and fibroblasts, it activates the neutral proteases.[23] This enhances wound contraction and reduces inflammatory mediators.

Pain scale used in this study is highly subjective and dependent on the individual experience. Patient discomfort and pain perception were recorded immediately, 1 day, and 1 week after surgery using VAS. On comparing the mean change in VAS scores between the groups, patients experienced less pain in sites treated with the laser than other sites. This could be due to the prevention of pain signal transmission by laser therapy from the injured site to the brain. This reduces pain perception and increases the production and release of endorphins and enkephalins (natural pain-relieving chemicals) by decreasing nerve sensitivity significantly.[24] Chow et al.[25] reported inhibitory effects of lasers on the peripheral nerves by slowing down the conduction velocity and/or decreasing the amplitude of action potentials.

However, few studies[26,27] reported that there was no significant difference between groups, and few studies[17,18] reported that participants experienced more pain with LA-OFD. This could be due to the use of different laser application modes.

Although many clinical trials concerning the application of lasers in periodontology, there are relatively few longitudinal clinical trials. This has led to an ongoing disagreement among practitioners regarding the proper application of lasers to the treatment of periodontitis. However, there is no clear evidence that laser applications improve clinical outcomes.

Further multi-centric studies with a large sample, long-term follow-up, and evaluation of radiographic, microbiological, and histological parameters will be necessary to sustain the clinical findings. Future studies should focus on laser settings, optimal type, wavelength, power, energy delivered, and method of using lasers adjunct to periodontal surgery.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.