Comparative Evaluation of 980-nm Diode Laser Therapy as an Adjunct to Scaling and Root Planing Versus Scaling And Root Planing Alone In Diabetic Patients With Chronic Periodontitis

Introduction

Chronic periodontitis is caused by pathogenic plaque biofilm that leads to bacteria-induced inflammatory destruction of the alveolar bone and periodontal ligament resulting in the formation of the pocket.^1,2

A periodontal pocket is defined as the pathologic deepening of the gingival sulcus.³ The goal of periodontal therapy is to alter the inflammatory processes and its success depends on the effective removal of supragingival and subgingival bacterial biofilms and the smear layer.^4,5

The formation of biofilms on the exposed root surface within periodontal pockets impedes the infiltration of antibiotics, hence mechanical disruption of the biofilm is necessary during periodontal treatment.⁶

Periodontal therapy can be broadly classified into surgical or non-surgical procedures.⁷ In non-surgical periodontal treatment, debridement of the diseased root surface is performed by scaling and root planing using hand or ultrasonic instruments. It produces a smear layer which may affect the healing of periodontal tissues. With frequent use of antibiotics, there is a potential risk of producing resistant microorganisms. Therefore, laser therapy has been proposed as an adjunctive treatment to conventional periodontal therapy which facilitates treatment and has the potential to improve healing. This study aims to evaluate the clinical effects of multiple applications of a 980nm diode laser with scaling and root planing treatments (SRP) versus the effects of SRP alone in diabetic patients

Methodology

A split-mouth clinical study was conducted at the Department of Periodontics and Oral Implantology at A.M.E’S Dental College and Hospital, Raichur, Karnataka, India. A total of 30 type 2 diabetic patients of 40–60 years with moderate periodontitis were selected. Each patient had a minimum of one tooth in each quadrant with pocket depths of 6 mm and no periodontal treatment within the previous 6 months. The exclusion criteria were removable partial dentures, fixed prosthodontic appliances, and teeth with grade III mobility. Patients were explained the nature of the study and the outcome of it, followed by which verbal and written consent was obtained. The study was approved by the ethical committee of A.M.E’S Dental College and Hospital, Raichur, Karnataka, India. The entire study was completed within 15 months including the follow-up.

Demographic characteristics such as age, sex, and medical history of the patients were recorded. Clinical measurements were obtained at six points around each tooth (mesio-facial, midfacial, disto-facial, mesio-lingual, mid-lingual, and disto-lingual) using a graduated UNC-15 (University of North Carolina) probe. The following periodontal clinical parameters were measured at baseline, 6, and 12 weeks: plaque index (PI; Silness & Loe -1964), Sulcus bleeding index (SBI; Muhlemann H.R and Son S–1971), probing pocket depth (PPD), and clinical attachment level (CAL). The patients were advised blood investigations which included total count, differential count, hemoglobin percentage, bleeding and clotting time, and fasting blood sugar.

All 30 patients were subjected to full-mouth supragingival scaling. After two weeks, subgingival SRP in a single appointment was carried out. Right and left quadrants were randomly subjected to the control group (CG) which included SRP alone and the laser group (LG) which included SRP along with laser application. The laser therapy was performed three times in LG on days 1, 3, and 7 after SRP treatment using a Denlase diode laser (figure A) of 980nm wavelength with a 300nm fiber-optic delivery system (figure B). The latter was introduced parallel to the cementum for 20 seconds per tooth. The optical fiber was cleaned before and between the laser treatments of each tooth. The fiber was introduced at 1 mm less than the pocket depth during the clinical measurements using the tip of the fiber cannula (figure C). The settings of the unit were as follows: Power of 1.5 W with a continuous mode (laser beam operated through a foot switch). The laser treated sites were irrigated with saline and oral hygiene instructions were given.

Statistical Analysis

Descriptive and inferential statistical analyses were carried out. Results on continuous measurements were presented as mean ± SD and results on categorical measurements were presented in number (%). The level of significance was fixed at p= 0.05 and any value less than or equal to 0.05 was considered to be statistically insignificant. Student t-test (two-tailed, unpaired) was applied to find the significance of study parameters on the continuous scale between the two groups. Analysis of variance (ANOVA) was applied to find the significance of the study parameters between the three groups. The statistical software IBM SPSS statistics 20.0 (IBM Corporation, Armonk, NY, USA) was used for the analysis of the data.

Results

Among thirty patients with type 2 diabetes, none of the patients missed their follow-up visits. The PI, SBI, PPD, and CAL results (mean ±SD) for CG and LG at baseline, 6, and 12 weeks are shown in table 1. Highly significant reductions in all parameters were observed in both groups after 6 and 12 weeks (P <0.001). Comparison of all parameters in both the groups from day 1 to 6 weeks and from baseline to 12 weeks are shown in table 2. A significant reduction in PPD was seen in the LG from baseline to 12 weeks (P=0.015), reduction in sulcus bleeding was observed slightly more in the LG compared to the CG. There was a slight improvement in PI and CAL from day 1 to 6 weeks and from baseline to 12 weeks in the LG, however, no significant differences in SBI, PI, and CAL were observed between the groups after 6 and 12 weeks (P = 0.3, P=0.3 and P=0.19 respectively).

Discussion

Laser irradiation has been reported to exhibit bactericidal and detoxification effects without producing a layer of smear. It provides favorable conditions for the attachment of periodontal tissue.⁶ The ablation of tissue is excellent with a laser treatment that is expected to enhance the healing of periodontal tissues, destroying the inflamed lesions and epithelial lining of the soft tissue wall within the periodontal pockets.⁷

LASER is an acronym for “Light Amplification by Stimulated Emission of Radiation.” The stimulated emission of a photon by an excited atom which triggers the release of a subsequent photon is responsible for the generation of a coherent, monochromatic, and collimated form of light or laser. Since it has good tissue penetration and is well absorbed in the pigmented tissues, it can specifically target the pigmented bacteria and granulation tissue.⁸

Diabetes mellitus is a disease of metabolic dysregulation characterized by hypofunction or lack of function of b-cells of islets of Langerhans in the pancreas leading to high blood glucose levels and excretion of sugar in the urine.⁹ A variety of periodontal changes have been described in diabetic patients, such as a tendency towards enlarged gingiva, sessile or pedunculated gingival polyps, polypoid gingival proliferation, abscess formation, periodontitis, and mobile teeth.⁹

Diabetes mellitus is broadly classified into type 1, type 2, gestational diabetes, and other specific types. Individuals with type 2 diabetes have relative rather than absolute insulin deficiency.¹⁰

Following recent developments in laser technology, several types of lasers have been identified as promising new technical modalities for the decontamination of periodontal pockets and root surfaces in nonsurgical treatment owing to their effective ablation effects. Currently, lasers are employed as an adjunct to conventional mechanical instruments, such as hand instruments or ultrasonic scalers in the clinic.

Diode lasers belong to the deeply penetrating types of laser. White et al. ¹¹ reported that the width of the coagulation layer following irradiation in continuous mode was more than 1.0 mm in an incision of bovine oral soft tissue in vitro. However, depending on the experimental conditions and method of evaluation, the width of the coagulation layer is considerably different. Goharkhay et al. ¹² demonstrated that the width of softtissue damage on pig oral mucosa was 20–100 μ in the continuous wave and pulsed mode at 0.5–4.5 W. Beer et al. ¹³ stated that the average depth of necrosis and the depth of reversible damage in the incision on bovine liver specimens were approximately 80–190 μ and 300 μ to 2 mm, respectively, for the pulsed mode, and were 70– 150 μ and 150–600 μ, respectively, for the micro-pulsed mode, depending on the speed of probe movement at 1.2–2.2 W. In the case of periodontal tissues, the laser is absorbed by the tissues and the absorbed light energy is converted into heat and constitutes a photothermal event. Rastegar et al.¹⁴ examined the absorption of laser radiation by oxygenated and deoxygenated blood and reported absorption of 4.5 cm and penetration of 2.2 mm in both blood.

As the effects of laser treatment of periodontal tissue depend on the wavelength, pulse energy, frequency, and spot size used, the diode laser was considered an interesting alternative to conventional lasers in periodontal treatment. Furthermore, the laser is a treatment modality that is finding very good acceptance by patients because it involves minimal pain.

The benefits from diode laser along with the traditional procedures of SRP in the periodontal pockets treatment include bactericidal effect, curettage effect, bio stimulating effect that enhances the acceleration of mitotic processes without causing any structural and/ or functional alterations according to the studies of Benedicenti (2008).¹⁵

According to Salvi et al., ¹⁶ in addition to the bactericidal effect of laser, decreased periodontal inflammation may also be related to the decrease of prostaglandin E2 (PGE2) levels due to the effects of laser treatment. PGE2 levels increase in the periodontal connective tissues of the periodontal lesions being a potent stimulator of inflammation and bone resorption.

According to previous reports, another advantage of diode laser therapy may be its positive effects on wound healing. A study by Safavi et al.¹⁷ demonstrated that laser therapy may inhibit the production of interleukin 1β (IL-1β), and interferon γ (IFN-γ), while it may have a stimulatory effect on platelet-derived growth factor (PDGF) and transforming growth factor β (TGF-β). Conlan (1996)¹⁸ found an increase of about 50% in the proliferation and differentiation of fibroblasts and collagen synthesis within the periodontal ligament, and the process according to Choi (2010),¹⁹ begins to manifest between the next 24–48 hours to laser treatment and intensifies especially after the 72 hours. All these reactions accelerate the healing process and encourage a speedy recovery in clinical attachment. Laser light not only eliminates the bacteria but also inactivates bacterial toxins diffused within the root cementum.

The effectiveness of SRP in the treatment of periodontal pockets to reduce bacterial plaque on the root surface is universally accepted. Sbardone et al. ²⁰ stated that pockets treated with a single application of scaling and root planing exhibited a microflora similar to that in healthy sites at 7 days after treatment. The use of diode laser in addition to SRP in periodontal treatment of type 2 diabetes individuals makes a positive contribution to the reduction of local inflammation and periodontal healing. Diode laser therapy may significantly enhance the patient’s comfort during the post-operative healing and hence can be useful in diabetic patients where delayed healing is reported. In the current study, the clinical benefits of diode laser along with traditional periodontal therapy were evaluated in type 2 diabetic patients. The results showed that SRP along with a 980nm diode laser provided a statistically significant difference in probing pocket depth from baseline to 12 weeks. There was a decrease in the clinical parameters (PPD, CAL, PI, and SBI) in both the control and laser-treated sites from day 1 to 6 weeks and day 1 to 12 weeks. Reduced inflammation of gingiva was noted in laser and SRPtreated sites. Walter Dukic et al.²¹ compared laser to SRP alone, where repeated applications of a 980nm diode laser with SRP on the 1st, 3rd, and 7th day in moderate and severe periodontitis cases showed a slight improvement in moderate periodontitis and no improvement in severe periodontitis. Caruso et al.²² concluded that there was a little improvement in the clinical parameters of laser therapy in periodontal pockets. Finally, it is needed to access the standard criteria for periodontal laser therapy in terms of LASER energy, its duration of application, irradiation mode, and type of laser used; this would analyze the results accurately.

Conclusion

The objective of the current study was to compare the effectiveness of a diode laser (980 nm) when used along with SRP to that of SRP alone in chronic periodontitis with type 2 diabetes.

The conventional approach to periodontal pockets is the removal of supra and subgingival bacterial deposits. Scaling and root planing is still considered the gold standard to compare other methods. Several clinical studies conducted in the past few decades confirmed the effectiveness of the non-surgical approach in treating periodontal infection. This study has some limitations including small sample size and short duration. The present investigation showed that the treatment with diode laser along with SRP may lead to statistically significant differences in clinical parameters (PPD, CAL, PI, and BOP) at baseline, 6, and 12 weeks in both groups and statistically significant differences in PPD from baseline to 12 weeks in laser group compared to the control group. Therefore, diode lasers along with SRP may represent a newer approach to the treatment of periodontal pockets with chronic periodontitis.

The results in other studies and this study may state the importance of the application of the laser, which depends on the laser wavelength, energy, duration, frequency, and spot size that has been used. When these factors are taken into account, diode lasers can be considered as an adjunct to SRP in periodontal treatment. In addition, it has good tissue penetration and can specifically target pigmented bacteria and granulation tissue.

Therefore, diode lasers have a beneficial effect on sites affected by periodontal disease when treated in combination with scaling and root planing in diabetic patients where periodontal surgery is contraindicated.

Conflict of Interest

None