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Table of Contents
ORIGINAL ARTICLE
Year : 2017  |  Volume : 7  |  Issue : 1  |  Page : 15-22

Photodynamic therapy: Re-entry in the treatment of chronic periodontitis: A clinical study


Department of Periodontology, DAPM RV Dental College, Bengaluru, Karnataka, India

Date of Web Publication29-May-2017

Correspondence Address:
Latha Govindappa
#45/1, 1st Main, 4th Cross, Chocolate Factory Road, Tavarekere, BTM 1st Stage, Bangalore - 560 029, Karnataka
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/jid.jid_74_16

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   Abstract 

Background: Periodontitis is an inflammatory disease of multifactorial origin affecting the supporting tissues of the periodontium. Photodynamic therapy (PDT) involves the photosensitizer dye and a light source to induce reactive oxygen species (singlet oxygen) and causes destruction of microorganisms. Aim: The aim of this study was to compare the efficacy of PDT with scaling and root planing (SRP) and also to compare the efficacy of two different concentrations of photosensitizer (methylene blue 0.005% and 0.01%) in the treatment of chronic periodontitis. Materials and Methodology: Forty-five patients affected by moderate-to-severe chronic periodontitis were included in the study and were divided into three groups. The clinical parameters, plaque index (PI), gingival index (GI), and probing pocket depth were recorded at baseline, 1 month, and 3 months of time interval. After SRP, PDT was performed using methylene blue dye (0.005% and 0.01%) and diode laser with 665 nm wavelength for 60 s. Results: At 1 and 3 months after treatment, there were no statistically significant differences between the groups with regard to reduction in PI, GI, and probing pocket depth in all the three groups (P > 0.05). Conclusion: The additional application of a single episode of PDT to SRP failed to result in an additional improvement in terms of reduction in plaque score, GI score, and pocket probing depth.

Keywords: Gingival index, periodontitis, photodynamic therapy, plaque index, pocket probing depth, scaling and root planing


How to cite this article:
Suchetha A, Govindappa L, Sapna N, Apoorva S M, Darshan B M, Khawar S. Photodynamic therapy: Re-entry in the treatment of chronic periodontitis: A clinical study. J Interdiscip Dentistry 2017;7:15-22

How to cite this URL:
Suchetha A, Govindappa L, Sapna N, Apoorva S M, Darshan B M, Khawar S. Photodynamic therapy: Re-entry in the treatment of chronic periodontitis: A clinical study. J Interdiscip Dentistry [serial online] 2017 [cited 2017 Oct 21];7:15-22. Available from: http://www.jidonline.com/text.asp?2017/7/1/15/207156




   Clinical Relevance to Interdisciplinary Dentistry Top


  • Photodynamic therapy (PDT) which can be used in the treatment of periodontitis
  • PDT can be treated in the treatment of peri-implantitis
  • PDT can also be used in the disinfection of root canals.



   Introduction Top


Periodontitis is an inflammatory disease, which is characterized by the presence of gingival inflammation, periodontal pocket formation, loss of connective tissue and alveolar bone of the teeth that results from the extent of subgingival inflammation induced by bacteria in the biofilm.[1] The main objective of periodontal therapy is to eliminate deposits of bacteria and bacterial niches by removing the supragingival and subgingival biofilms.[2] Although mechanical instrumentation is still regarded as important modality which forms the gold standard of periodontal therapy, it has some limitations and even with therapy, some patients still have attachment loss probably due to the persistence of periodontal pathogens and subsequent recolonization of the subgingival area, which pose a challenge for the patient and the therapist in plaque control.[3] Thus, the advent of other options to improve the effectiveness of periodontal therapy is needed due to limited access to furcation areas, concavities, grooves, distal sites of molars, and deep pockets found during conventional periodontal therapy.[4] The increase in bacterial resistance due to the use of systemic antibiotics could also justify the appearance of other adjuvants for established periodontal treatment.[5],[6]

Recent advances in technology have led to a constant drive to develop novel approaches for the treatment of periodontal diseases. Photodynamic therapy (PDT) is also known as photoradiation therapy, phototherapy, or photochemotherapy.[7]

Phototherapy began in ancient Greece, Egypt, and India and was disappeared for decades. The use of contemporary PDT was first reported by Danish Physician, Niels Finsen. He successfully demonstrated PDT by employing heat-filtered light from carbon arc lamp (The Finsen Lamp) in the treatment of lupus vulgaris. PDT was introduced in medical therapy in the year 1904 as the light-induced inactivation of cells, microorganisms, or molecules and is based on the principle that a photosensitizer (i.e., a photoactivatable substance) binds to the target cells and can be activated by light of a suitable wavelength in the presence of oxygen.[8]

PDT is an oxygen-dependent photochemical reaction that occurs upon exposure to a particular wavelength of light in the presence of a suitable photosensitizer dye. The various photosensitizer dyes were used including (a) tricyclic dyes with different mesoatoms, for example, acridine orange, proflavine, riboflavin, methylene blue, toluidine blue, fluorescein, and erythrosine, (b) tetrapyrroles, for example, porphyrins, derivatives, chlorophyll, phylloerythrin, and phthalocyanines, and (c) furocoumarins, for example, psoralen and its methoxy derivatives, xanthotoxin, and bergapten.

The various light sources were utilized including lasers of different wavelengths and nonlaser light sources such as light emitting diodes. The photochemical reaction results in generation of cytotoxic species such as superoxide, hydroxyl radicals, hydrogen peroxide, and singlet oxygen. Among these, reactive oxygen species (singlet oxygen) plays a major role in microbial destruction as it can interact with a large number of biological substrates inducing oxidative damage to the cell membrane and cell wall of bacteria, fungi, and viruses.

Various studies have used different concentrations of photosensitizer dye (0.01% or 0.005%), so the present study was conducted to determine any variations in the outcome of different concentrations applied in the PDT procedure. The present study was aimed at evaluating the efficacy of PDT in the nonsurgical treatment of chronic periodontitis with SRP and to compare the efficacy of two different concentrations of methylene blue (0.005% and 0.01%) photosensitizer.


   Materials and Methodology Top


A total of 45 patients having chronic periodontitis (based on the 1999 Classification of Periodontal Diseases and Conditions) were selected from the outpatients visiting the Department of Periodontology, DAPM RV Dental College, Bengaluru. The ethical clearance for the study was obtained from the Ethical Committee and review board of the institution. This clinical study was conducted from October 2014 to April 2015. The patients of both sexes aged between 30 and 65 years, with a minimum of six teeth having periodontal pocket depth of ≥5 mm and with no systemic conditions that would contraindicate routine periodontal procedures, were included in the study. Patients with the following criteria were excluded from the study: patients who have received periodontal therapy within the past 6 months, pregnant and lactating patients, patients who have taken antibiotics within 6 months period preceding study, teeth exhibiting Class II and Class III mobility, smokers, acute oral infections, and patients with known allergy to methylene blue dye. All participants signed the informed consent form after being informed about the treatment protocol.

Participants were divided into three groups as follows:

  • Group I (n = 15): Those to be treated with scaling and root planning (SRP) only
  • Group II (n = 15): Those to be treated with SRP + PDT (0.005% methylene blue) for the treatment of chronic periodontitis
  • Group III (n = 15): Those to be treated with SRP + PDT (0.01% methylene blue) for the treatment of chronic periodontitis.


All the patients were subjected to a full-mouth periodontal examination at six sites per tooth (excluding the third molar). After oral hygiene instructions, all patients received full-mouth SRP under local anesthesia using both hand instruments and ultrasonic device. The following clinical parameters such as plaque index (PI) (Silness and Loe 1964), gingival index (GI) (Loe and Silness 1963), and pocket probing depth (PPD) (using UNC 15 Probe) were recorded at baseline, 1 month, and 3 months. In Group II and III participants after thorough SRP, safety goggles were provided to the patient, operator, and the assistant to prevent damage to the eyes by laser.

Using a blunt needle, the methylene blue photosensitizer solution with a concentration of 0.005% and 0.01%, respectively, was applied to the base of the pocket, starting from the apical end of the pocket moving coronally to avoid entrapment of air bubbles. Three minutes later, all pockets were thoroughly rinsed with sterile saline to remove the excessive photosensitizer. Immediately after rinsing, the diode laser (Sirona) with 660 nm wavelength and 1 mW of output equipped with a fiber optic probe tip was placed at the depth of the pocket and moved circumferentially in sweeping motion around the teeth for 1 min as shown in [Figure 1], [Figure 2], [Figure 3], [Figure 4]. Patients were recalled after 1 month and 3 months posttherapy and all the clinical parameters were recorded. Statistical analysis was carried out by one-way analysis of variance (ANOVA).
Figure 1: Preoperative pocket probing depth

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Figure 2: Application of methylene blue and saline irrigation to remove the excess dye

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Figure 3: Laser activation of methylene blue dye (photosensitizer)

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Figure 4: Three months of posttreatment probing photos

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   Results Top


The mean PI scores at baseline, 1 month, and 3 months were 2.58 ± 0.20, 1.25 ± 0.15, and 1.08 ± 0.08, respectively, in Group I; 2.37 ± 0.22, 1.19 ± 0.14, and 1.04 ± 0.07 in Group II; and 2.31 ± 0.15, 1.15 ± 0.15, and 1.05 ± 0.07, respectively, in Group III. The mean PI was found to be statistically significant among all the groups between all the time intervals (P < 0.05). The results of PI are shown in [Table 1], [Table 2] and [Graph 1],[Graph 4],[Graph 5],[Graph 6].
Table 1: Intragroup comparison of plaque index

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Table 2: Intergroup comparison of plaque index

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The mean GI scores at baseline, 1 month, and 3 months were 2.30 ± 0.23, 1.18 ± 0.13, and 1.05 ± 0.05, respectively, in Group I; 2.37 ± 0.18, 1.15 ± 0.13, and 1.07 ± 0.08, respectively, in Group II; and 2.26 ± 0.20, 1.22 ± 0.12, and 1.06 ± 0.08, respectively, in Group III.

The mean GI was found to be statistically significant among all the groups between all the time intervals (P < 0.05). The result of GI is shown in [Table 3], [Table 4] and [Graph 2], [Graph 4],[Graph 5],[Graph 6].
Table 3: Intragroup comparison of gingival index

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Table 4: Intergroup comparison of gingival index

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The mean PPD scores at baseline, 1 month, and 3 months were 6.69 ± 1.07, 5.59 ± 1.23, and 5.53 ± 1.33, respectively, in Group I; 6.29 ± 1.08, 5.88 ± 1.35, and 5.05 ± 1.05, respectively, in Group II; and 6.40 ± 0.98, 5.65 ± 1.25, and 5.00 ± 1.02, respectively, in Group III. The mean PPD was found to be statistically significant among all the groups between all the time intervals (P < 0.05); however, on intergroup comparison, the mean PPD was found to be statistically significant among all the groups (P > 0.05). The result of PPD is shown in [Table 5], [Table 6] and [Graph 4],[Graph 5],[Graph 6]. On intergroup comparison, the results of the study were statistically insignificant (P > 0.05) [Table 2], [Table 4], [Table 6] and [Graph 4],[Graph 5],[Graph 6].
Table 5: Intragroup comparison of pocket probing depth

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Table 6: Intergroup comparison of pocket probing depth

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   Discussion Top


Periodontitis being multifactorial in etiology results in loss of supporting tissues of the periodontium and also presents with therapeutic difficulties. Microbial plaque accumulation is considered to be one of the main factors of this disease as bacteria have the ability to grow in biofilms and are beyond the reach of antimicrobial chemical agents. In addition, the anatomical complexity of tooth roots causes them to be predisposed to the development of many niches for bacterial deposits, making eradication of periodontopathogens more difficult both mechanically and chemically.

Furthermore, some periodontopathogens (e.g., Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis) can penetrate into and persist in epithelial cells of the periodontal pockets and the gingiva, thus avoiding the efficacy of conventional antimicrobial drugs. In addition, the systemic antibiotic therapy is limited by the minimum inhibitory concentration of the drug, which is difficult to achieve in gingival crevicular fluid and scarcely possible in bacterial biofilms. Moreover, there is also a problem of increasing bacterial resistance developing for the systemic antibiotics.[9],[10],[11],[12]

Conventional treatment such as SRP does not completely eliminate periodontal pathogens, especially in deep periodontal pockets. Moreover, it does not prevent this microorganism from penetrating into periodontal tissue. In addition, this predisposes the periodontal pockets to recolonization and recurrence of the disease.[13],[14],[15],[16],[17]

PDT was discovered in the beginning of the 20th century and then implemented in medicine. It consists of three elements: harmless visible light, a nontoxic photosensitizer, and oxygen. It is based on the principle that the photosensitizer (or photoactivatable substance) binds to the targeted cells and then can be activated by light of the appropriate wavelength in the presence of oxygen. This results in the generation of singlet oxygen and free radicals, which are toxic to certain cells and bacteria.[2],[18],[19],[20],[21]

The mechanism of the action of antibacterial PDT (aPDT) is that initially, a photosensitizer at ground state is activated to a highly energized triplet state by irradiation with the light of a certain wavelength. The excited photosensitizer has a longer lifetime, which results in interactions with the surrounding molecules, and it is generally assumed that at the triplet state, the generation of cytotoxic species occurs. The triplet-state photosensitizer reacts with biomolecules using two different pathways (two types of reactions).[22]

Antimicrobial photosensitizers such as porphyrins, phthalocyanines, and phenothiazines (e.g., methylene blue and toluidine blue O) have been reported to penetrate into Gram-positive and Gram-negative bacteria. The positive charge seems to promote the binding of the photosensitizer to the Gram-negative bacterial membrane and leads to its localized damage, resulting in an increase in its permeability. Hence, toluidine blue O and methylene blue are commonly used in aPDT.[23],[24] Various studies have been conducted previously using different concentrations of methylene blue, but there were no studies conducted to compare both concentrations.[25],[26]

Hence, the present study was planned to evaluate the efficacy of PDT with SRP, and also we compared the efficacy of two different concentrations of methylene blue photosensitizer in PDT.

The methylene blue photosensitizer gets activated at a wavelength of 660 nm to 720 nm of laser light which is in the red zone of light spectrum. In the present study, laser light (Sirona) with the wavelength of 660 nm was used at 1 mW of energy. The depth of penetration of laser light is ranging from 0.5 mm to 1.5 mm.

In the present study, all the precautions were followed to prevent the laser-associated damages to the patient as well as to the operator. The clinical parameters observed are PI, GI, and PPD.[25] Data obtained by the study were analyzed by using ANOVA followed by Bonferroni post hoc analysis.

The results obtained from this study showed that the mean PI scores at baseline, 1 month, and 3 months in Group I were 2.58 ± 0.20, 1.25 ± 0.15, and 1.08 ± 0.08, respectively. In Group II, the mean PI scores at baseline, 1 month, and 3 months were 2.37 ± 0.22, 1.19 ± 0.14, and 1.04 ± 0.07, respectively. In Group III, the mean PI scores at baseline, 1 month, and 3 months were 2.31 ± 0.15, 1.15 ± 0.15, and 1.05 ± 0.07, respectively. The mean PI was found to be statistically significant at baseline (P < 0.05) between Group I and Group II but was statistically insignificant at 1 month and 3 months of time intervals (P > 0.05) and was statistically insignificant at all-time intervals in Group III (P > 0.05). However, when compared between Group II and Group III, Group II showed more reduction in PI scores at 1 month and 3 months of time interval comparatively. The results obtained in the present study in plaque reduction scores were in agreement with the studies conducted by Ge et al. and Berakdar et al.[25],[26] In the present study, there was no statistically significant reduction in plaque scores observed.

The results obtained in this study showed that the mean GI scores at baseline, 1 month, and 3 months in Group I were 2.30 ± 0.23, 1.25 ± 0.15, and 1.08 ± 0.08, respectively. In Group II, the mean PI scores at baseline, 1 month, and 3 months were 2.37 ± 0.22, 1.19 ± 0.14, and 1.04 ± 0.07, respectively. In Group III, the mean GI scores at baseline, 1 month, and 3 months were 2.31 ± 0.15, 1.15 ± 0.15, and 1.05 ± 0.07, respectively. The mean GI index score was found to be statistically significant at baseline (P < 0.05) in Group I and Group II but was statistically insignificant at 1 month and 3 months of time intervals (P > 0.05) and was statistically insignificant at all-time intervals in Group III (P > 0.05). However, when compared between Group II and Group III, Group III showed more reduction in GI scores at 1 month and 3 months of time interval. The results obtained from this study were in agreement with the study conducted by de Oliveira et al.[27],[28] In the present study, there was no statistically significant reduction in GI scores observed.

The results obtained from this study showed that the mean PPD scores at baseline, 1 month, and 3 months in Group I were 6.69 ± 1.08, 5.88 ± 1.35, and 5.53 ± 1.33, respectively. In Group II, the mean PPD scores at baseline, 1 month, and 3 months were 6.29 ± 1.07, 5.59 ± 1.23, and 5.05 ± 1.05, respectively. In Group III, the mean PPD at baseline, 1 month, and 3 months were 6.40 ± 0.98, 5.65 ± 1.25, and 5.00 ± 1.02, respectively. The mean PPD score was not found to be statistically significant at all-time intervals (P > 0.05). However, when compared between Group II and Group III, Group III showed more reduction in probing pocket depth at baseline and 1 month of time interval comparatively. The results obtained from this study were in agreement with the study conducted by de Oliveira et al.[26],[28] In the present study, there was no statistically significant reduction in probing pocket depth observed.

The results of the present study signify that the PDT for the treatment of chronic periodontitis has similar outcome that of conventional therapy (SRP). In the present study, PDT did not show any added benefit over SRP in the treatment of chronic periodontitis. In addition, there was no statistically significant difference in the two concentrations of photosensitizer dye in the treatment outcome. Limitations of the study include small sample size, included in the study, short duration of observation, and single application of PDT.


   Conclusion Top


The results obtained from the present study concludes that the conventional mechanical therapy and SRP alone have a beneficial effect on the nonsurgical management of chronic periodontitis, PDT as an adjunct to SRP did not have any added benefit over the conventional SRP alone. However, PDT showed similar clinical outcome as that of SRP, and there was no difference in the clinical outcome of two different concentrations of methylene blue photosensitizer. PDT can be used as an adjunct to SRP in the management of periodontitis. Further long-term studies with large sample size are required to obtain predictable results.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
   References Top

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Ge LH, Shu R, Shen MH. Effect of photodynamic therapy on IL-1beta and MMP-8 in gingival crevicular fluid of chronic periodontitis. Shanghai Kou Qiang Yi Xue 2008;17:10-4.  Back to cited text no. 25
    
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Berakdar M, Callaway A, Eddin MF, Ross A, Willershausen B. Comparison between scaling-root-planing (SRP) and SRP/photodynamic therapy: Six-month study. Head Face Med 2012;8:12.  Back to cited text no. 26
    
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    Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4]
 
 
    Tables

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



 

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