Journal of Indian Society of Periodontology

: 2015  |  Volume : 19  |  Issue : 1  |  Page : 43--48

Evaluation of the use of a 940 nm diode laser as an adjunct in flap surgery for treatment of chronic periodontitis

Tanya Marguerite Lobo, Dilip Ganpat Pol 
 Department of Periodontology, Government Dental College and Hospital (Affiliated to Maharashtra University of Health Sciences, Nashik), Mumbai, Maharashtra, India

Correspondence Address:
Tanya Marguerite Lobo
Flat No. 201, 2nd Floor, A Wing, Wits End Co operative Housing Society, 70 D, Hill Road, Bandra (West), Mumbai 400 050, Maharashtra


Background: Lasers have several potential benefits such as antibacterial effect and stimulation of wound healing. In addition, hemostasis and delaying epithelial migration may facilitate the outcome of flap surgery. There is a minimal research and evidence currently available for the optimum method of use of a diode laser in flap surgery and its benefit and safety. Hence, this study aimed to investigate the adjunctive effect of diode laser irradiation in open flap debridement (OFD), while treating chronic periodontitis. Materials and Methods: A total of 30 patients with generalized chronic moderate to severe periodontitis with pocket probing depth (PD) ≥5 mm post - Phase I therapy were selected for a split-mouth study. Flap surgery with adjunctive diode laser irradiation was performed in the test quadrant while routine OFD was done in the control quadrant. Clinical parameters including PD, clinical attachment level, gingival recession, plaque index, gingival index and tooth mobility were recorded at baseline, 3 months and 6 months following treatment. In addition, patients«SQ» rating of procedural pain as well as the development of complications postoperatively was assessed. Results: All clinical parameters significantly improved after therapy without any statistically significant difference between the two groups for any of the parameters. The exception was a significantly greater reduction in gingival inflammation in the laser treated group. The laser treatment was acceptable to the patient and did not cause any complications. Conclusion: The diode laser can be safely and effectively used as an adjunct to the treatment of chronic periodontitis with the advantage of decreased gingival inflammation.

How to cite this article:
Lobo TM, Pol DG. Evaluation of the use of a 940 nm diode laser as an adjunct in flap surgery for treatment of chronic periodontitis.J Indian Soc Periodontol 2015;19:43-48

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Lobo TM, Pol DG. Evaluation of the use of a 940 nm diode laser as an adjunct in flap surgery for treatment of chronic periodontitis. J Indian Soc Periodontol [serial online] 2015 [cited 2022 Aug 15 ];19:43-48
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Chronic periodontitis is one of the most prevalent oral conditions the world over. [1] Pathogenic plaque micro-flora, host immune responses, and environmental factors play a major etiologic role and cause both direct as well as host-mediated tissue injury. [2] Elimination or modification of these factors is the basic aspect of treatment, which arrests or controls the disease process. In addition, the aim is to regenerate the tissues and restore function with methods, which are predictable and achieve long-term benefits.

Complete mechanical debridement being the "gold standard" of periodontal treatment, [3] still does not eliminate the micro-organisms in the soft tissue wall of the pocket, neither is complete resection of the diseased tissues possible. Additional soft tissue curettage procedures using ultrasonics and other chemicals as well as several adjunctive locally delivered agents such as antimicrobials, antiseptic agents, antiinflammatory agents, and host - modulating agents have been evaluated for enhancing the treatment outcome of chronic periodontitis with varying degrees of success. [4] However, the predictability of these treatments is not certain as well as antimicrobial drugs may lead to the development of resistant microbial strains.

Other methods for enhancing regeneration such as bio-mimetics, grafts and barrier membranes have shown to benefit the treatment outcome, but may increase the treatment costs, and additional invasive procedures may not be acceptable to the patient. Laser technology, specifically the diode laser is gaining popularity in general dental practice with potential benefits in a wide range of applications. [5] Lasers have provided us with a potential alternative to simultaneously remove the diseased soft tissues, target the micro-organisms as well as stimulate wound healing. Several lasers such as the carbon dioxide (CO 2 ), Ho: YAG, Nd: YAG, diode, Er: YAG have been experimentally utilized for soft tissue periodontal procedures. [6] Laser use produces less postoperative swelling, reduces inflammation and is also relatively painless.

Several clinical studies have supported the antibacterial effect of lasers in periodontal pockets. [ 7],[8],[9],[10] Some studies have even reported tissue regeneration on histologic evaluation following laser mediated periodontal therapy utilizing the "laser assisted new attachment procedure." [11],[12] Furthermore, several authors have reported enhanced outcomes using lasers to de-epithelize the inner lining of the flap based on the principle of guided tissue regeneration. [13],[14],[15]

The diode laser is the most popular choice of laser technology for the general dental practitioner since it is economical, portable and convenient to use. In addition, since it has good tissue penetration, [16] and is well absorbed in pigmented tissues, it can specifically target the pigmented bacteria and granulation tissue. [17] In vitro evaluation has shown the diode laser to achieve a more complete elimination of the epithelial lining of the periodontal pocket. [18] Soft tissue surgical procedures using lasers were found to have good hemostasis, sterilization and minimal postoperative pain when compared to conventional surgical procedures. [19]

However, the evidence available so far is conflicting. Systematic reviews have to date not shown the lasers in general to provide any additional benefit over conventional mechanical debridement modalities in nonsurgical therapy, [20] and very few trials have been conducted on the use of diode lasers as an adjunct to periodontal surgery and the parameters for safe as well as effective laser use. Hence, the aim of this study was to evaluate the adjunctive benefit of a diode laser to conventional mechanical debridement in the surgical treatment of chronic periodontitis.


A total of 30 patients in the age group of 25-60 years having moderate to severe "chronic periodontitis," undergoing treatment at the Department of "Periodontology" were selected for the study. The study was approved by the local ethical committee. The treatment plan was explained to the patients and their written informed consent was obtained.

Patients who had at least two quadrants with three teeth each having a pocket probing depth (PD) of ≥5 mm post - Phase I therapy were included. Patients having systemic diseases e.g. diabetes, heart disease, immuno-compromised patients and patients on medications, which could affect the periodontium were excluded. In addition, smokers (current or smoking within the last 5 years), pregnant women, patients having recent history of antibiotic use (within the previous 3 months) and patients allergic to medications to be prescribed were excluded from the study.

Study design

A split-mouth study design was used by selecting two quadrants in each of the 30 patients. The two assessment groups were - the control was "open flap debridement (OFD)" and test group "OFD + diode laser." Prior to the surgery, the selected quadrants were randomly allocated (by the toss of a coin) into control and test group where the control sites were treated with OFD and the test sites with OFD + diode laser [Figure 1].{Figure 1}

Measurement of clinical parameters

All the patients were subjected to clinical periodontal examination by a single examiner. The clinical probing measurements that are PD, clinical attachment level (CAL) and gingival recession (GR) were measured using a "University of North Carolina - 15" periodontal probe. 3 teeth/quadrant were selected and the deepest site was recorded of each tooth. Custom made acrylic stents were prepared on study models and an indelible marker was used to record the location as well as the direction of probing to standardize the probe angulation in two dimensions [Figure 2]. The recordings were repeated at 3 months and 6 months. The reference point for measuring the attachment level was the cemento-enamel junction.{Figure 2}

Plaque index (PI) [21] and gingival index (GI) [22] were calculated at baseline, followed by posttreatment at 3 months and 6 months recall visits. The average of the mesio-buccal, facial, disto-buccal, and lingual values was considered as the index value per tooth.

In addition, tooth mobility (TM) was assessed at baseline, 3 months and 6 months using the Miller's index. [23] Radiographs were taken at baseline and 6 months postoperatively and assessed for changes in the bone to rule out any detrimental effect of the laser used in close proximity to the bone. Procedural pain experience of the patient was recorded objectively using a visual analog scale (VAS), [24] a 10 cm scale, which had markings from 0 to 10 depicting the pain intensity from minimal to maximal. In addition, the development of other complications such as necrosis, swelling, bleeding, delayed healing, infection, and scar formation was checked for and noted 1-week postoperatively.

Periodontal surgery

The surgical procedures were performed by a single operator. The control quadrant OFD procedure was first performed. Two weeks later the test side surgery was performed similarly with diode laser irradiation of the inner lining of the flap.

The modified Widman flap technique was used. [25] Meticulous defect debridement and root planning were carried out using curettes.

In the test group, a 940 nm diode laser unit (having a maximum power output of 7 W) was used with a 7 mm long, 300 micron diameter, and disposable fiber-optic tip for energy delivery to the site [Figure 3].{Figure 3}

The laser at power of 1.5 W in contact mode was used by placing the fiber-optic tip at a 45° angle to the inner aspect of the flap, avoiding directing it toward the bone and teeth [Figure 4]. Horizontal overlapping strokes were used on the inner lining of both facial and palatal flaps for about 10 s in relation to each tooth. Following this, the site was irrigated with normal saline. High volume suction apparatus was additionally used to clear the field and the tip debris was removed with a moistened cotton swab. The prelasing and postlasing appearance of the tissue can be appreciated in [Figure 5] and [Figure 6], respectively showing the light brownish appearance of the tissue and a bloodless field postlasing.{Figure 4}{Figure 5}{Figure 6}

No osseous re-contouring was done. Routine flap closure using 3-0 black silk sutures was done. The surgical area was covered with a noneugenol periodontal dressing - Coe-Pak (GC America Inc. Statistical Package for Social Sciences-SPSS Inc., Alsip, Illinois, USA). Routine postoperative instructions were given along with antibiotic and antiinflammatory medication - amoxicillin, 500 mg thrice daily and diclofenac sodium 100 mg twice daily for 4 days respectively. About 0.2% chlorhexidine digluconate mouthrinse twice daily for 1-week. The patient was advised to avoid brushing on the operated site for 1-week.

The sutures and the periodontal dressing were removed 1-week postoperatively, and the sites were evaluated for any signs of delayed healing, flap necrosis, infection, and scar formation.

In addition, the patients were questioned regarding the experience of postoperative swelling and bleeding. Reinforcement of the patients' oral hygiene regime was done at all the recall appointments and the patient was advised to use a soft bristled tooth-brush. Postsurgical measurements were done at 3 months and 6 months postoperatively.

Statistical analysis

The data were analyzed using the Statistical Package for Social Sciences (SPSS version 11.5 software, SPSS Inc., Chicago, Illinois, USA) using nonparametric tests. The intra-group variations were analyzed using Wilcoxon's signed-rank test, while inter-group comparisons were drawn using the Mann-Whitney U-test. The values of the three sites were averaged to obtain the value for the quadrant.


The 30 patients sample comprised of 20 females and 10 males in the age range of 26-47 years. 60 quadrants were treated totally - 30 as test group and 30 as control in a split-mouth design. The average value of 3 teeth in each quadrant (i.e. test or control group) for each patient was considered while assessing the clinical parameters. The mean values with standard deviation at baseline, 3 months and 6 months are presented in [Table 1] and the percentage change in the parameters in [Table 2].{Table 1}{Table 2}

Probing depth

The mean probing pocket depth at baseline in the OFD group was 6.08 ± 0.91 mm which was reduced to 2.81 ± 0.59 mm at 3 months and 2.56 ± 0.49 mm at 6 months. In the OFD + laser group the baseline value was 6.02 ± 0.81 mm, which reduced to 2.53 ± 0.53 mm at 3 months and 2.35 ± 0.50 mm at 6 months. The OFD and OFD + laser groups showed a percentage reduction in PD of 53.2 and 57.4 at 3 months and 58.2 and 60.2 at 6 months, which was statistically highly significant (P < 0.05). However, there was an insignificant difference statistically and clinically between the two groups with P > 0.05 at both 3 and 6 months intervals [Graph 1a].

Clinical attachment level

The CAL showed a significant reduction from baseline in both groups indicating a gain in the attachment level. The mean CAL at baseline in the OFD Group was 6.64 ± 0.84 mm and OFD + laser was 6.83 ± 1.09 mm, which was reduced to 4.87 ± 0.63 mm and 5.23 ± 0.79 mm at 3 months, showing a percentage reduction of 26.1 and 22.9, which was statistically highly significant (P < 0.05). Similarly, at 6 months, CAL reduced to 4.75 ± 0.47 mm in OFD group and 5.18 ± 0.78 mm in the OFD + laser group showing a percentage change in CAL of 28.8 and 23.6 which was also statistically highly significant (P < 0.05). The difference in CAL change in the two groups at 3 months and 6 months however, was statistically insignificant with P > 0.05 [Graph 1b].

Gingival recession - [Graph 1c] increased significantly in each group from baseline over the 6-month period. There was an insignificant difference between the test and control group values.

Indices - plaque index, gingival index and tooth mobility index

The intra-group comparisons-showed that both groups the control (OFD) group and the test (OFD + Laser) group had significant reduction in PI, GI and TM index at all intervals from the baseline as shown in [Table 1] and Graph 2a-c.

However, the inter-group comparison between the test (OFD + laser) and the control (OFD) group showed that the differences for all these parameters were found to be statistically insignificant at all the recorded recall intervals as shown in [Table 2] except for the "GI" scores. Graph 2b. It was found that the "GI" scores at all points of time were significantly less in the laser treated group (P = 0.01) than in the control (OFD) group implying a greater reduction in the gingival inflammation sustained in the laser treated test group.

Patient acceptance of the procedure and assessment of complications

The procedural pain evaluated on the VAS revealed mean scores of 1.90 ± 1.18 and 2.07 ± 1.17 for the control group and test group, respectively.

Complications were seen in a few cases (2/group) postsurgical treatment. These included mild postoperative intraoral swelling which subsided within a week and in others slightly delayed healing where the inflammation persisted over 1-week taking an additional week to subside.

Radiographic changes were minimal in both control and laser treated sites with a slight gain 6 months postoperatively. The difference in the groups was insignificant.


The diode laser is an effective soft tissue laser for incision, hemostasis and coagulation. [4] At a wavelength in the range of 800-980 nm it is well-absorbed by pigmented tissues and so can selectively target the darkened, inflamed tissues and pigmented bacteria. In fact some trials have confirmed the bactericidal effect of the diode laser. [6],[7],[8],[9] [INLINE:1] [INLINE:2]

However being deeply penetrating it is important to adjust the parameters within a safe and efficacious range so as to adequately remove the epithelial lining. It potentially has a "guided tissue regeneration-like" effect by retarding the epithelial migration and may achieve a more complete epithelial removal than conventional mechanical methods as shown in vitro. [18]

Low-level lasers have shown to reduce inflammatory mediators, facilitate collagen synthesis, angiogenesis and stimulate the release of growth factors. Low-level diode laser therapy in vitro has shown to increase the proliferation of human fibroblasts. [26] Furthermore, reduction in the production of inflammatory mediators has been observed. [27],[28]

There are however conflicting reports on the use of lasers as an adjunct to the nonsurgical treatment of chronic periodontitis, with several systematic reviews showing no additional advantage of laser use in general. [6],[20] This had also been stated by the American Academy of Periodontology. [29],[30] However, since published reports on the use of diode lasers in periodontal flap surgery are relatively few until date it was decided to evaluate the same. [31],[32]

The results of the present study indicate that the diode laser can be safely used as an adjunct to conventional therapy. However, no significant additional benefits except for its ability to cause a significant decrease in the gingival inflammation were observed.

"Clinical attachment level" being the "gold standard" for evaluating the success of periodontal therapy [3] and PD of the pocket being an important factor affecting the long-term stability of the results, these were the primary outcomes measured. Additionally, GR and TM changes were assessed. No significant differences were found in these parameters using a diode laser as an adjunct. These results are in accordance with the clinical trials conducted so far. [31]

The "PI" was recorded to monitor the oral hygiene status of the patients and showed a significant decrease posttreatment. However, a slightly increasing trend with time implies the need to re-motivate the patient at each recall interval, which was done.

"Gingival index" was assessed to evaluate the gingival condition clinically. Our study showed a significant reduction in the gingival inflammation in the laser treated group compared to the control group when used as an adjunct to flap surgery. Although, the precise mechanism was not established it could be possibly be attributed to the bacterial reduction achieved by the laser as well as decreased inflammation and stimulation of tissue healing.

As it is important for the patient to be comfortable with the treatment, it was decided to evaluate procedural pain on a VAS. Interestingly, in the cases where flap surgery was performed along with laser use there was a slightly though insignificantly higher pain experience. This could be attributed to the pressure during contact of the sharp fiber-optic tip of the laser on the inner flap lining.

Radiographic evaluation showed that the diode laser used in proximity to the bone did not have detrimental effects. Also tissue healing was uneventful postlaser use. Moreover, so the diode laser can be safely used in the power range of 1-1.5 W without any complications.

Furthermore, it was observed that adequate hemostasis was achieved using the diode laser on the inner surface of the flap leaving a light brownish tissue, which proceeded to heal normally. In many cases the tissue adaptation postlaser use appeared to be more favorable than in case of the control sites.

In addition, certain drawbacks such as the inability to remove hard deposits, risk of thermal damage to the hard tissues, the infrastructure required and high investment cost for the laser have to be weighed along with the benefits. Along with this, the time taken for the laser procedure is more and the laser equipment has to be used cautiously to prevent damage to vision and accidents.

From this study, it can be concluded that the use of the diode laser for this application did not significantly benefit the treatment outcome on the whole. Short term benefit of reduction in gingival inflammation could potentially benefit the outcomes in diseased soft tissues with a larger inflammatory component.

Also, certain limitations regarding the study such as lack of a blinded design as well as the lack of standardization of the amount of laser energy delivered could have influenced the observations.


The results of the present study indicate that diode laser used as an adjunct to in OFD did not significantly enhance the treatment outcome. However, since there was a significant clinical improvement in case of gingival inflammation, it can be safely and effectively used to achieve the same and can aid in tissue healing. Further research is required to provide evidence for the benefit of diode laser use in flap surgery.


The authors wish to thank Dr. Rajesh P. Gaikwad, H.O.D. Department of Periodontology and Staff of Radiology Department, Government Dental College, Mumbai for their help in radiography.


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