Multiple Sessions of Antimicrobial Photodynamic Therapy Improve Periodontal Outcomes in Patients with Down Syndrome: A 12-Month Randomized Clinical Trial

Background/Objectives: Individuals with Down syndrome (DS) often present with severe periodontal disease at a young age. Adjuvant treatments to scaling and root planing (SRP), such as antimicrobial photodynamic therapy (aPDT), may benefit this population. This study evaluated the effectiveness of aPDT as an adjunct to SRP in individuals with DS. A randomized, double-blind, parallel trial was conducted with 37 individuals with DS. Methods: The test group (aPDT; n = 18) received SRP + aPDT, while the control group (C group; n = 19) received SRP only. For aPDT, a red laser (658 nm; 0.1 W; 2229 J/cm2; 40 s sweeping with optical fiber) combined with methylene blue (MB) (100 µg/mL) was applied across repeated sessions (on days 3, 7, and 14). Clinical parameters, such as plaque index (PI), clinical attachment level (CAL), probing depth (PD), and bleeding on probing (BOP), were recorded at baseline and after 3, 6, and 12 months of treatment. Statistical analyses were performed using parametric and non-parametric tests (p < 0.05). Results: Both treatments promoted improvements in all clinical periodontal parameters (p < 0.05). The aPDT group showed a statistically significant reduction in CAL at 3 months (aPDT = 4.58 mm vs. C = 4.72 mm; p < 0.05) and 12 months (aPDT = 4.59 mm vs. C = 4.84 mm; p < 0.05). Conclusions: aPDT improved periodontal health in the long term through a stable gain in attachment.

Antimicrobial photodynamic therapy in the nonsurgical treatment of periodontitis in patients with HIV infection: a systematic review and meta-analysis

The aim of this systematic review and meta-analysis (SRM) was to evaluate the effectiveness of the adjunctive use of antimicrobial photodynamic therapy (aPDT) in non-surgical periodontal treatment (NSPT) in subjects with Human Immunodeficiency Virus (HIV) and periodontitis. This SRM was registered in PROSPERO (CRD42023410180) and followed the guidelines of PRISMA 2020. Searches were performed in different electronic databases. Risk of bias was performed using the Cochrane Risk of Bias tool (RoB 2.0) for randomized clinical trials (RCT). Meta-analysis was performed using Rev Man software. The mean difference (MD) measure of effect was calculated, the random effect model was applied with a 95% confidence interval, and heterogeneity was tested by the I2 index. The certainty of the evidence was rated using GRADE. A total of 1118 records were screened, and four studies were included. There was a greater reduction in the microbial load of periodontopathogens after NSPT with aPDT. Meta-analysis showed that probing depth (post 3 and 6 months) and clinical attachment loss (post 6 months) were lower for the aPDT-treated group than the NSPT alone: MD -0.39 [-0.74; -0.05], p = 0.02; MD -0.70 [-0.99; -0.41], p < 0.0001; MD -0.84 [-1,34; -0.34], p = 0.0001, respectively. Overall, the studies had a low risk of bias and, the certainty of evidence was rated as moderate. It is suggested that aPDT is a promising adjuvant therapy, showing efficacy in the reduction of the microbial load and in some clinical parameters of individuals with periodontitis and HIV.

Antimicrobial Resistance: Is There a 'Light' at the End of the Tunnel?

In recent years, with the increases in microorganisms that express a multitude of antimicrobial resistance (AMR) mechanisms, the threat of antimicrobial resistance in the global population has reached critical levels. The introduction of the COVID-19 pandemic has further contributed to the influx of infections caused by multidrug-resistant organisms (MDROs), which has placed significant pressure on healthcare systems. For over a century, the potential for light-based approaches targeted at combatting both cancer and infectious diseases has been proposed. They offer effective killing of microbial pathogens, regardless of AMR status, and have not typically been associated with high propensities of resistance development. To that end, the goal of this review is to describe the different mechanisms that drive AMR, including intrinsic, phenotypic, and acquired resistance mechanisms. Additionally, the different light-based approaches, including antimicrobial photodynamic therapy (aPDT), antimicrobial blue light (aBL), and ultraviolet (UV) light, will be discussed as potential alternatives or adjunct therapies with conventional antimicrobials. Lastly, we will evaluate the feasibility and requirements associated with integration of light-based approaches into the clinical pipeline.

Clinical applications of antimicrobial photodynamic therapy in dentistry

Given the emergence of resistant bacterial strains and novel microorganisms that globally threaten human life, moving toward new treatment modalities for microbial infections has become a priority more than ever. Antimicrobial photodynamic therapy (aPDT) has been introduced as a promising and non-invasive local and adjuvant treatment in several oral infectious diseases. Its efficacy for elimination of bacterial, fungal, and viral infections and key pathogens such as Streptococcus mutans, Porphyromonas gingivalis, Candida albicans, and Enterococcus faecalis have been investigated by many invitro and clinical studies. Researchers have also investigated methods of increasing the efficacy of such treatment modalities by amazing developments in the production of natural, nano based, and targeted photosensitizers. As clinical studies have an important role in paving the way towards evidence-based applications in oral infection treatment by this method, the current review aimed to provide an overall view of potential clinical applications in this field and summarize the data of available randomized controlled clinical studies conducted on the applications of aPDT in dentistry and investigate its future horizons in the dental practice. Four databases including PubMed (Medline), Web of Science, Scopus and Embase were searched up to September 2022 to retrieve related clinical studies. There are several clinical studies reporting aPDT as an effective adjunctive treatment modality capable of reducing pathogenic bacterial loads in periodontal and peri-implant, and persistent endodontic infections. Clinical evidence also reveals a therapeutic potential for aPDT in prevention and reduction of cariogenic organisms and treatment of infections with fungal or viral origins, however, the number of randomized clinical studies in these groups are much less. Altogether, various photosensitizers have been used and it is still not possible to recommend specific irradiation parameters due to heterogenicity among studies. Reaching effective clinical protocols and parameters of this treatment is difficult and requires further high quality randomized controlled trials focusing on specific PS and irradiation parameters that have shown to have clinical efficacy and are able to reduce pathogenic bacterial loads with sufficient follow-up periods.

The Effect of Photodynamic Therapy on the Early Outcome of Implants Placed on Patients with Periodontitis

Background: Immediate implant is a subtype of implant that is placed following tooth extraction within the socket without further delay. These implants are known to preserve the alveolar bone and minimize the total number of surgical interventions in a patient. 4 Photodynamic therapy (PDT) augments nonsurgical periodontal therapy using antibacterial mechanisms. PTD can be more effective in conjunction with scaling and root planing (SRP). The aim of this study is to assess the effects of PDT on the early outcomes of implants placed on patients with periodontitis with and without SRP at 9 months of follow-up. Materials and methods: A total of 23 implants were placed in 14 patients, with 11 in the test group and 12 in the control group. SRP was carried out prior to immediate implant placement in control sites, and PDT adjunctive to SRP (SRP + PDT) was performed in test sites before immediate implant placement. Plaque index, gingival index, probing pocket depth, clinical attachment level, and radiovisiographs were procured at baseline, 3 months, 6 months, and 9 months. Primary stability was examined at the time of implant placement, and the healing index was recorded a week later. Results: At the end of the 9 months of the study period, (SRP + PDT) group had a mean marginal bone loss of 0.95 mm, and the control group had 1.08 mm. Clinical parameters such as plaque index, gingival index, clinical attachment level, and probing depth showed definitive improvement after 9 months, compared with the baseline, but when the test and control groups were compared, the difference was statistically significant for plaque index and probing depth. The implants in both groups were followed up for a period of 9 months. There was an improvement in marginal bone loss but was not statistically significant. The survival of immediate implants in the PDT group was not different from those in the scaling and root planing group. Conclusion: The effect of PTD can be beneficially used as an adjunct to SRP. However, the effects were not significant. Photodynamic therapy can be effectively used as an adjunct to SRP owing to the better outcomes using PDT.

Efficacy of laser monotherapy or non-surgical mechanical instrumentation in the management of untreated periodontitis patients. A systematic review and meta-analysis

OBJECTIVE

To evaluate and compare the effects of laser monotherapy with non-surgical mechanical instrumentation alone in untreated periodontitis patients.

MATERIALS AND METHODS

A focused question was formulated based on the Population, Intervention, Comparison, Outcome, and Study design criteria (PICOS): in patients with untreated periodontitis, does laser mono-therapy provide adjunctive effects on pocket probing depth (PPD) changes compared with non-surgical instrumentation alone? Both randomized controlled clinical trials (RCTs) and controlled clinical trials (CCTs) were included. The results of the meta-analyses are expressed as weighted mean differences (WMD) and reported according to the PRISMA guidelines.

RESULTS

The search yielded 1268 records, out of which 8 articles could be included. With respect to PPD changes, a meta-analysis including 5 articles (n = 148) failed to identify statistically significant differences in favor of laser monotherapy for PPD change (WMD = 0.14 mm; 95% CI: - 0.04/0.32; z = 1.51; p = 0.132) nor for clinical attachment level (CAL) (WMD = 0.04 mm; 95% CI: - 0.35/0.42; z = 0.19; p = 0.850). Data on cost-effectiveness are lacking. One study reported patient-related outcome measures (PROMS).

CONCLUSIONS

In untreated periodontitis patients, laser monotherapy does not yield superior clinical benefits compared with non-surgical mechanical instrumentation alone.

CLINICAL RELEVANCE

In untreated periodontitis patients, mechanical instrumentation with hand and/or ultrasonic instruments remains the standard of care.

Antimicrobial photodynamic therapy can be an effective adjuvant for surgical wound healing in cattle

BACKGROUND

Rumenostomy is a useful procedure commonly performed in cattle for medical treatment of domestic ruminants with forestomach diseases. Methylene blue (MB)-mediated antimicrobial photodynamic therapy (APDT) has been broadly investigated to treat infected wounds.

AIM

The aim of the study was to evaluate the effectiveness of MB-mediated APDT (MB-APDT) combined with chlorhexidine and zinc oxide ointment on wound healing process after rumenostomy.

METHODS

Fourteen Nelore bulls were subjected to rumenostomy procedure. Animals were randomly divided into MB-APDT (MB associated with a red diode laser performed immediately after surgery and repeated on days 3, 5, 7 and 10) and control groups. Daily care included topical cleaning with chlorhexidine 2% followed by topical zinc oxide ointment. Animals were followed-up until the 28th day.

RESULTS

Wounds presented a better post-surgical profile in MB-APDT group when it was compared with the control group. In MB-APDT group, it was also possible to observe less pain on palpation of wounds borders, less edema and inflammatory exudate. Additionally, animals from MB-APDT group were faster discharged from the cattle care facility.

CONCLUSION

Our results support the use of MB-APDT for the post-surgical management of rumenostomy. This pilot study ratifies the use of APDT in cattle and also suggests that it could be performed for other surgical procedures as a complementary approach or an alternative for topical administration of antibiotics.

Oral manifestations of HIV: Can they be an indicator of disease severity? (A systematic review)

OBJECTIVE

To review the existing research literature on the paradigm that the oral lesions could be an indicator of the disease severity with the objective of documenting the current status of research, highlighting its major findings.

MATERIAL AND METHODS

Publications were identified through a careful search, of which a majority focused on oral lesions as an indicator for HIV progression. A PubMed journal search of 10 years OF period publication (2009-2019) for "oral lesion, oral manifestation, indicator, HIV and HIV-associated" was performed and analysed. Various research methods were included within the study criteria including clinical study, clinical trial, comparative study and randomised control trial.

RESULTS

A total 33 studies were obtained and analysed, including cohort study, cross-sectional study, case-control study, clinical trial, retrospective observational analysis study, prospective observational study and randomised control trial. The most common oral lesions found in the studies were Kaposi sarcoma (KS), followed by oral candidiasis, periodontitis, necrotising ulcerative gingivitis (NUG), necrotising ulcerative periodontitis (NUP) and oral hairy leucoplakia (OHL). The early diagnosis and accurate treatment plan were very important to indicate the disease severity related to HIV infection.

CONCLUSION

Oral lesions reported in 39% articles and could be an indicator of HIV disease severity due to its effects on decreased cluster-differentiated (CD4+) T-cell count and increased viral load.

Laser-Assisted aPDT Protocols in Randomized Controlled Clinical Trials in Dentistry: A Systematic Review

BACKGROUND

Antimicrobial photodynamic therapy (aPDT) has been proposed as an effective alternative method for the adjunctive treatment of all classes of oral infections. The multifactorial nature of its mechanism of action correlates with various influencing factors, involving parameters concerning both the photosensitizer and the light delivery system. This study aims to critically evaluate the recorded parameters of aPDT applications that use lasers as the light source in randomized clinical trials in dentistry.

METHODS

PubMed and Cochrane search engines were used to identify human clinical trials of aPDT therapy in dentistry. After applying specific keywords, additional filters, inclusion and exclusion criteria, the initial number of 7744 articles was reduced to 38.

RESULTS

Almost one-half of the articles presented incomplete parameters, whilst the others had different protocols, even with the same photosensitizer and for the same field of application.

CONCLUSIONS

No safe recommendation for aPDT protocols can be extrapolated for clinical use. Further research investigations should be performed with clear protocols, so that standardization for their potential dental applications can be achieved.

A review of antimicrobial photodynamic therapy (aPDT) in periodontitis

Introduction:Periodontitis is an inflammatory disease caused by a multitude of pathogens, that eventually affects the entirety of all periodontal tissues and may lead to tooth mobility or even tooth loss. The destruction of said tissues occurs via 2 pathways: a direct pathway (defense mechanisms belonging to the pathogens) and an indirect pathway (the host’s immune system). Therapy is complex and requires strict follow-ups in order to prevent relapse. Aim: Our objective was to determine whether or not aPDT can be considered to be an effective adjunctive approach to the current standard initial treatment method when dealing with periodontitis (scaling/root planing). Methods: We performed an electronical search of the PubMed and ScienceDirect data bases starting from January 2014 and up to May 2019. Eligibility criteria included English-language systematic reviews and randomized clinical trials which evaluated the efficiency of aPDT, and that had been carried out on human subjects with permanent dentition. We excluded studies and reviews that were focused on the microbiology and/or immunology in photodynamic therapy and also those that used other LASER treatment modalities than aPDT. Results: Current literature displays many opinions regarding periodontal therapy with adjunctive aPDT, but it seems to be mainly regarded as a safe, effective and easy-to-use approach. Conclusion: aPDT seems to be efficient in the treatment of periodontitis when carried out additionally to classical scaling/root planing. Residual pockets seem to respond well to aPDT, as opposed to subsequent debridement flap elevation and its consequences on hard and soft tissues. However, further studies with a stricter treatment protocol and subsequent follow-ups are required in order to obtain a firmer conclusion. Key words: periodontitis LASER, periodontitis aPDT, periodontitis photodynamic therapy,

Clinical efficacy of photodynamic therapy in the treatment of necrotizing ulcerative periodontitis among HIV seropositive patients: A randomized controlled clinical trial

AIM

To evaluate clinical periodontal and microbiological parameters after the treatment with adjunctive antimicrobial photodynamic therapy (APDT) among HIV seropositive and seronegative patients with necrotizing ulcerative periodontitis (NUP).

MATERIALS AND METHODS

Seropositive patients (Group-I) and health controls (Group-II) with NUP were randomized into two groups and further underwent APDT and scaling and root planing (SRP), respectively. Clinical periodontal parameters including full mouth plaque index (FMPI), bleeding on probing (FMBOP), probing depth (PD) and clinical attachment level (CAL) gain were assessed. Levels of bacteria including Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg) and Tannerella forsythia (Tf) were assessed using PCR technique. All assessments were done at baseline, 3 months and 6 months.

RESULTS

All periodontal parameters including FMPI, FMBOP, PD and CAL significantly improved in both HIV seropositive and seronegative patients. The reduction in mean PD was higher only with the APDT treatment among group II patients compared to group I patients at follow-up (p < 0.05). The gain in mean CAL was higher only with the APDT treatment among group I and group II patients at follow-up (p < 0.05). All bacterial levels reduced from baseline to follow-up with both APDT and SRP treatments in both groups (p < 0.05). APDT showed significantly reduced counts of Aa and Tf at 3 months, and only Aa at 6 months among HIV seropositive patients, while the levels of Pg and Tf significantly reduced at 3 months and only Aa at 6 months in the seronegative patients, respectively (p < 0.05).

CONCLUSION

Application of antimicrobial photodynamic therapy as an adjunct to scaling and root planing was effective in improving clinical periodontal parameters and bacterial levels among HIV positive patients with NUP. However, the improvement was not greater when compared with HIV seronegative patients.

Clinical and microbiological effects of multiple applications of antibacterial photodynamic therapy in periodontal maintenance patients. A randomized controlled clinical study

BACKGROUND

At present, very limited data are available on the clinical and microbiological outcomes obtained following repeated application of aPDT following one single mechanical debridement.

OBJECTIVE

To evaluate clinically and microbiologically the outcomes following one single session of subgingival mechanical debridement (scaling and root planing; e.g. SRP) followed by 1x immediate application of aPDT and 2 x subsequent use of aPDT without SRP.

MATERIALS AND METHODS

Forty patients diagnosed with generalized chronic periodontitis that were enrolled in periodontal maintenance (supportive periodontal therapy) program, were randomly assigned to one of the two treatments: 1. SRP by means of ultrasonic and hand instruments followed by one single session of SRP followed by 1x immediate application of aPDT and 2 x subsequent applications of aPDT without SRP (test) or 2. SRP alone (control). The following clinical parameters were recorded at baseline, at 3 and 6 months: Full-Mouth Plaque Scores (FMPS), Full-Mouth Bleeding Scores (BOP), Probing Pocket Depth (PPD), Clinical Attachment Level (CAL) and Gingival Recession (RC). Additionally, microbiological samples were evaluated at baseline and six months after treatment. The primary outcome variable was BOP.

RESULTS

Both treatments improved statistically significantly (p < 0.05) the FMPS, PPD and CAL values, while no statistically significant changes occurred in terms of RC. In the test group, BOP decreased statistically significantly (p < 0.05) after 3 and 6 months, while in the control group the respective values decreased statistically significantly only at 3 months. Both treatments reduced statistically significantly the total bacteria counts (TBC) after 6 months (p < 0.05). At 6 months, the use of SRP and aPDT resulted in a statistically significant decrease in the number of all tested bacteria except A. actinomycetemcomitans while the use of SRP alone resulted only in a statistically significant decrease in the numbers of P. gingivalis, T. denticola and T. forsythia.

CONCLUSIONS

In periodontal patients enrolled in a maintenance program one single session of SRP followed by 3x application of aPDT, enhanced the clinical and microbiological outcomes compared to SRP alone.

Pore forming channels as a drug delivery system for photodynamic therapy in cancer associated with nanoscintillators

According to the World Health Organization (WHO), cancer is one of main causes of death worldwide, with 8.2 million people dying from this disease in 2012. Because of this, new forms of treatments or improvement of current treatments are crucial. In this regard, Photodynamic therapy (PDT) has been used to successfully treat cancers that can be easily accessed externally or by fibre-optic endoscopes, such as skin, bladder and esophagus cancers. In addition, this therapy can used alongside radiotherapy and chemotherapy in order to kill cancer cells. The main problem in implementing PDT is penetration of visible light deeper than 10 mm in tissues, due to scattering and absorption by tissue chromophores. Unfortunately, this excludes several internal organs affected by cancer. Another issue in this regard is the use of a selective cancer cell-photosensitizing compound. Nevertheless, several groups have recently developed scintillation nanoparticles, which can be stimulated by X-rays, thereby making this a possible solution for light production in deeper tissues. Alternative approaches have also been developed, such as photosensitizer structure modifications and cell membrane permeabilizing agents. In this context, certain channels lead to transitory plasma membrane permeability changes, such as pannexin, connexin hemmichannels, TRPV1-4 and P2×7, which allow for the non-selective passage of molecules up to 1,000 Da. Herein, we discuss the particular case of the P2×7 receptor-associated pore as a drug delivery system for hydrophilic substances to be applied in PDT, which could also be carried out with other channels. Methylene blue (MB) is a low cost dye used as a prototype photosensitizer, approved for clinical use in several other clinical conditions, as well as photodynamic therapy for fungi infections.

The Effect of Photodynamic Therapy in the Treatment of Chronic Periodontitis: A Review of Literature

Introduction: Chronic periodontitis is the most common periodontal disease which is related to the chronic accumulation of bacterial plaque. Since mechanical methods are not sufficient in the treatment of this disease, administration of local/systemic antibiotic is recommended following mechanical debridement. However, side effects of antibiotics such as microbial resistance and patient allergy led to development of alternative methods. One of these suggested methods is the antimicrobial photodynamic therapy (aPDT). PDT is a local noninvasive treatment modality without the side effects caused by antibiotics. The aim of this study was to review the articles related to the application of PDT with laser in the treatment of chronic periodontitis. Review of literature: In the present review of literature, the authors used key words such as chronic periodontitis, laser and photodynamic therapy, and conducted a literature search via Google Scholar and PubMed for the period of 1990 to 2015. A total of 47 articles in English were found. The articles that were not associated with the topic of research and review articles were deleted and only clinical trials were evaluated. After reviewing 23 articles' abstracts, the full texts of 16 articles were analyzed. Conclusion: Considering the safety, the lack of side effects and general advantages like more patient compliance, the PDT treatment with scaling and root planing (SRP) is recommended as an efficient adjunctive modality for the treatment of localized chronic periodontitis especially during the maintenance phase in non-surgical treatment.

Systematic review and meta-analysis on the nonsurgical treatment of chronic periodontitis by means of scaling and root planing with or without adjuncts

BACKGROUND

Conduct a systematic review and meta-analysis on nonsurgical treatment of patients with chronic periodontitis by means of scaling and root planing (SRP) with or without adjuncts.

METHODS

A panel of experts convened by the American Dental Association Council on Scientific Affairs conducted a search of PubMed (MEDLINE) and Embase for randomized controlled trials of SRP with or without the use of adjuncts with clinical attachment level (CAL) outcomes in trials at least 6 months in duration and published in English through July 2014. The authors assessed individual study bias by using the Cochrane Risk of Bias Tool and conducted meta-analyses to obtain the summary effect estimates and their precision and to assess heterogeneity. The authors used funnel plots and Egger tests to assess publication bias when there were more than 10 studies. The authors used a modified version of the US Preventive Services Task Force methods to assess the overall level of certainty in the evidence.

RESULTS

The panel included 72 articles on the effectiveness of SRP with or without the following: systemic antimicrobials, a systemic host modulator (subantimicrobial-dose doxycycline), locally delivered antimicrobials (chlorhexidine chips, doxycycline hyclate gel, and minocycline microspheres), and a variety of nonsurgical lasers (photodynamic therapy with a diode laser, a diode laser, neodymium:yttrium-aluminum-garnet lasers, and erbium lasers).

CONCLUSIONS AND PRACTICAL IMPLICATIONS

With a moderate level of certainty, the panel found approximately a 0.5-millimeter average improvement in CAL with SRP. Combinations of SRP with assorted adjuncts resulted in a range of average CAL improvements between 0.2 and 0.6 mm over SRP alone. The panel judged the following 4 adjunctive therapies as beneficial with a moderate level of certainty: systemic subantimicrobial-dose doxycycline, systemic antimicrobials, chlorhexidine chips, and photodynamic therapy with a diode laser. There was a low level of certainty in the benefits of the other included adjunctive therapies. The panel provides clinical recommendations in the associated clinical practice guideline.

Adjunctive Application of Antimicrobial Photodynamic Therapy in Nonsurgical Periodontal Treatment: A Review of Literature

Periodontal disease is caused by dental plaque biofilms, and the removal of these biofilms from the root surface of teeth plays a central part in its treatment. The conventional treatment for periodontal disease fails to remove periodontal infection in a subset of cases, such as those with complicated root morphology. Adjunctive antimicrobial photodynamic therapy (aPDT) has been proposed as an additional treatment for this infectious disease. Many periodontal pathogenic bacteria are susceptible to low-power lasers in the presence of dyes, such as methylene blue, toluidine blue O, malachite green, and indocyanine green. aPDT uses these light-activated photosensitizer that is incorporated selectively by bacteria and absorbs a low-power laser/light with an appropriate wavelength to induce singlet oxygen and free radicals, which are toxic to bacteria. While this technique has been evaluated by many clinical studies, some systematic reviews and meta-analyses have reported controversial results about the benefits of aPDT for periodontal treatment. In the light of these previous reports, the aim of this review is to provide comprehensive information about aPDT and help extend knowledge of advanced laser therapy.

Treatment of Periodontal Disease with an Octenidine-based Antiseptic in HIV-positive Patients

OBJECTIVE

To evaluate the effects of a periodontal therapy with subsequent application of an octenidine (OCT)-based antiseptic in HIV-positive patients receiving highly active antiretroviral therapy.

METHODS

HIV-positive patients with a clinically diagnosed periodontal disease were randomly divided into two groups (n = 30/group). Both groups initially received a periodontal therapy. Patients in the OCT group additionally used an OCT-based mouthwash. Subgingival plaque samples and periodontal indices were analysed prior to treatment onset as well as one and 3 months post-treatment.

RESULTS

Periodontal therapy has resulted in a significant decrease in the values of all periodontal indices one and 3 months following the therapy completion (P = 0.000). The effects of the two applied therapeutic protocols differed significantly in terms of the variation in the PBI (F = 4.617; P = 0.017) and the PD (F = 3.203; P = 0.044) value. In the patients in the OCT group, a more pronounced decrease in the PBI and PD was noted at 1-month follow-up as well as a greater increase in the PD value 3 months upon treatment completion. In the OCT group, no more atypical microorganisms were detectable 1 month post-treatment, while in the control group they were found in 34.5% of patients.

CONCLUSIONS

The periodontal therapy bears good results in HIV-positive patients. Additional administration of OCT contributes to the significant decline in the PBI and DS values and eliminates atypical microorganisms within 1 month post-treatment. However, more favourable results were not noted in the OCT group at the 3-month assessment.

Photosensitisers - the progression from photodynamic therapy to anti-infective surfaces

INTRODUCTION

The application of light as a stimulus in pharmaceutical systems and the associated ability to provide precise spatiotemporal control over location, wavelength and intensity, allowing ease of external control independent of environmental conditionals, has led to its increased use. Of particular note is the use of light with photosensitisers.

AREAS COVERED

Photosensitisers are widely used in photodynamic therapy to cause a cidal effect towards cells on irradiation due to the generation of reactive oxygen species. These cidal effects have also been used to treat infectious diseases. The effects and benefits of photosensitisers in the treatment of such conditions are still being developed and further realised, with the design of novel delivery strategies. This review provides an overview of the realisation of the pharmaceutically relevant uses of photosensitisers, both in the context of current research and in terms of current clinical application, and looks to the future direction of research.

EXPERT OPINION

Substantial advances have been and are being made in the use of photosensitisers. Of particular note are their antimicrobial applications, due to absence of resistance that is so frequently associated with conventional treatments. Their potency of action and the ability to immobilise to polymeric supports is opening a wide range of possibilities with great potential for use in healthcare infection prevention strategies.

Photosensitization of in vitro biofilms formed on denture base resin

STATEMENT OF PROBLEM

Proper sterilization or disinfection of removable prostheses and surgical guides has been problematic in dental practice because of the absence of simple and low-cost techniques that do not cause damage to acrylic resins.

PURPOSE

The purpose of this study was to study the effect of photodynamic therapy against Streptococcus mutans, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans biofilms formed on acrylic resin specimens.

MATERIAL AND METHODS

The specimens were sterilized in ethylene oxide gas and submitted to in vitro biofilm growth. The photodynamic therapy consisted of the application of 0.05% methylene blue (P+) conjugated to irradiation with a light-emitting-diode of 630 nm and 150 mW (L+). The specimens were randomly divided into groups (n=5): negative control (P-L-); stained and irradiated at 10 J/cm(2) (P+L+ 10); stained and irradiated at 30 J/cm(2) (P+L+ 30); stained and not irradiated (P+L-); not stained and irradiated at 10 J/cm(2) (P-L+ 10); not stained and irradiated at 30 J/cm(2) (P-L+ 30); and gold standard (GS), sterilized. Afterward, the specimens were submitted to contact with culture medium agar for 10 minutes in petri plates, which were incubated for 48 hours at 37°C. The number of colony-forming units was obtained, and the data were expressed according to scores (1=0; 2=1-10; 3=11-100; 4=101-1000) and analyzed by the Friedman and Dunn tests (α=.05).

RESULTS

Streptococcus mutans was sensitized by (P+L-); P aeruginosa and C albicans were also sensitized by the dye but showed a slight microbial reduction with (P+L+ 30), as did S aureus (P>.05); E coli presented an initial score of 3 and achieved a bacterial reduction to score 2 with (P+L+ 30) (P=.039).

CONCLUSIONS

Photodynamic therapy was effective in reducing E coli counts on biofilms formed on acrylic resin specimens. The inhibition of microorganism growth tended to be directly proportional to the amount of energy provided by the light-emitting diode.

A novel approach to synthesize polymers for potential photodynamic therapy: from benzenedinitrile to phthalocyanine

RAFT synthesized polymers with benzenedinitrile side chains were converted to phthalocyanine conveniently, providing a novel method for making PDT polymers.

Effects of photodynamic therapy on Gram-positive and Gram-negative bacterial biofilms by bioluminescence imaging and scanning electron microscopic analysis

OBJECTIVE

The aim of this study was to test photodynamic therapy (PDT) as an alternative approach to biofilm disruption on dental hard tissue, We evaluated the effect of methylene blue and a 660 nm diode laser on the viability and architecture of Gram-positive and Gram-negative bacterial biofilms.

MATERIALS AND METHODS

Ten human teeth were inoculated with bioluminescent Pseudomonas aeruginosa or Enterococcus faecalis to form 3 day biofilms in prepared root canals. Bioluminescence imaging was used to serially quantify and evaluate the bacterial viability, and scanning electron microscopic (SEM) imaging was used to assess architecture and morphology of bacterial biofilm before and after PDT employing methylene blue and 40 mW, 660 nm diode laser light delivered into the root canal via a 300 μm fiber for 240 sec, resulting in a total energy of 9.6 J. The data were statistically analyzed with analysis of variance (ANOVA) followed by Tukey test.

RESULTS

The bacterial reduction showed a dose dependence; as the light energy increased, the bioluminescence decreased in both planktonic suspension and in biofilms. The SEM analysis showed a significant reduction of biofilm on the surface. PDT promoted disruption of the biofilm and the number of adherent bacteria was reduced.

CONCLUSIONS

The photodynamic effect seems to disrupt the biofilm by acting both on bacterial cells and on the extracellular matrix.

Photodynamic Therapy (PDT) Utilizing Multiple Light Sources Significantly Improves Clinical Efficacy and Subject Satisfaction with a Review of PDT Mechanisms of Action

Introduction:

Many topically applied devices and medicaments have been developed to give hope to people who want to reduce the signs of visible aging. All modalities have benefits and risks, and no single modality produces complete resolution of photoaging. Although approved by the US Food and Drug Administration for treatment of epithelial neoplasia, photodynamic therapy (PDT) is also reported to produce significant benefits in reducing photoaging. The goal of this study was to determine if clinical response and subject satisfaction can be improved for PDT while reducing downtime and increasing activation of the photosensitizer.

Materials and Methods:

In a regimen administered monthly for 3 treatments, 14 subjects participated in a prospective intervention pilot trial using an 830 nm light-emitting diode (LED), a 540 nm advanced fluorescence technology laser, a 570 nm advanced fluorescence technology laser, and a 633 nm LED. The photoactivation phase was initiated with the 830 nm LED 10 minutes after application of 20% 5-aminolevulinic acid, followed by each modality in listed order. Baseline global extrinsic aging scores were compared with scores 1 month after the final treatment. Subject satisfaction scores were also obtained 1 month after the final treatment.

Results:

Twelve subjects completed this trial. The global extrinsic aging score improved from a baseline of 3.3 to 1.0. Of these 12 subjects, 10 (84%) indicated that they were satisfied or very satisfied with the results 1 month after completion of the treatment.

Conclusions:

This photodynamic therapy regimen is very effective while being better tolerated and involving less downtime. The treatment can also be completed in a shorter time than regimens requiring a longer incubation time.