Photodynamic therapy for chronic periodontitis

Abstract

In the introduction, the author explains the microbiological aetiology of periodontitis (although the references may be too old), and justifies the adjunctive use of Antimicrobial Photodynamic therapy (aPDT) in periodontal therapy, based on their antimicrobial effects and on the limitations of other adjunctive therapies (such as local and systemic antimicrobials). Among these limitations, the increase in bacterial resistance and biofilm resistance are enumerated, although the second one should not be included, when these therapies are used as adjuncts to mechanical debridement.This review aimed to compare scaling and root planing (SRP) plus aPDT versus SRP alone. An extensive search lead to the evaluation of 14 full-text papers, and four of them were excluded due to the use of 'high-level lasers', a criterion that was not mentioned in the paper.Finally, four papers were included, two of them performed by the same research group.The studies presented some heterogeneity, with one of them following a split mouth-design. One of the most important issues of the review is that it is not reported how many sites were measured in each patient and how the sites were selected. In addition, it seems that the author has performed a site-based analysis, according to the data provided in the figures. A significant difference of 0.29mm in CAL change was calculated in the meta-analyses, and a non-significant difference of 0.11mm in PPD change, both favouring the adjunctive therapy, at the 12-week evaluation. The differences were of small magnitude with no associated adverse effects. However, the differences among the studies were obvious, with two studies with a clear impact in both variables 1,2 , and two studies (those performed by the same group) with smaller impact and minor differences among groups. 3,4 The first two studies had a 12-week follow up, while the last two had a 24-week duration, although the 12-week results were included in the meta-analysis. In addition, one of last two studies included patients in supportive periodontal therapy (already treated and following a secondary prevention program), despite the inclusion criterion of the review of 'untreated chronic periodontitis'.In the discussion, the limitations of this systematic review are acknowledged, including the design of the review with just one examiner. No mention is made of the need for patient-based analysis as opposed to site-based analysis. Site-based analysis is not considered adequate in periodontal therapy, since all the sites from the same patient are influenced by the same systemic factors (such as smoking or genetics), and therefore all the sites from different patients should not be combined. In addition, 12 weeks of follow-up may only be considered as short-term. Longer follow-ups are needed to define the real benefits of a therapy.In a recent commentary 5 , another systematic review on the topic was evaluated. 6 It included five papers, three papers in common with Data extraction and synthesis Data were extracted by a single reviewer using a ...

Lasers and the treatment of periodontitis: the essence and the noise

“…This lack of effect on A . actinomycetemcomitans may be related to deeper initial probing depth (> 6.00 mm) and/or deep penetration of the microbe into the pocket soft‐tissue wall .…”

“…P. gingivalis, Tannerella forsythia and Treponema denticola) following treatment with scaling and root planing + 980 nm diode but no treatment modality reduced the levels of A. actinomycetemcomitans. This lack of effect on A. actinomycetemcomitans may be related to deeper initial probing depth (> 6.00 mm) and/or deep penetration of the microbe into the pocket soft-tissue wall (97,177).…”

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“…It was previously found that photodynamic therapy (PDT) enhances anti-bacterial effect of conservative periodontal treatment (for overview see [1]). PDT can be defined as eradication of target cells by reactive oxygen species (ROS) produced by means of a photosensitizing compound and light of an appropriate wavelength.…”