Is Photodynamic Therapy an Effective Treatment for Periodontal and Peri-Implant Infections?

Efficacy of adjunctive photodynamic therapy to conventional mechanical debridement for peri-implant mucositis

OBJECTIVE

This meta-analysis was conducted to assess the effectiveness of photodynamic therapy (PDT) as an adjunct to conventional mechanical debridement (CMD) for the management of peri-implant mucositis (p-iM).

METHODS

We systematically searched four databases (PubMed, Embase, Web of Science, and Cochrane Library) for randomized controlled trials (RCTs) investigating PDT + CMD for p-iM from their inception to March 13, 2023. Meta-analysis was performed using RevMan 5.4 software.

RESULTS

Seven RCTs met the inclusion criteria. The meta-analysis revealed that PDT + CMD treatment was more effective than CMD alone in reducing probing depth (PD) (Mean Difference [MD]: -1.09, 95% Confidence Interval [CI]: -1.99 to -0.2, P = 0.02) and plaque index (PI) (MD: -2.06, 95% CI: -2.81 to -1.31, P < 0.00001). However, there was no statistically significant difference in the improvement of bleeding on probing (BOP) between the PDT + CMD groups and CMD groups (MD: -0.97, 95% CI: -2.81 to 0.88, P = 0.31).

CONCLUSIONS

Based on the current available evidence, this meta-analysis indicates that the addition of PDT to CMD significantly improves PD and PI compared to CMD alone in the treatment of p-iM. However, there is no significant difference in improving BOP.

Clostridioides difficile Biofilm

Clostridioides difficile infection (CDI), previously Clostridium difficile infection, is a symptomatic infection of the large intestine caused by the spore-forming anaerobic, gram-positive bacterium Clostridioides difficile. CDI is an important healthcare-associated disease worldwide, characterized by high levels of recurrence, morbidity, and mortality. CDI is observed at a higher rate in immunocompromised patients after antimicrobial therapy, with antibiotics disrupting the commensal microbiota and promoting C. difficile colonization of the gastrointestinal tract.A rise in clinical isolates resistant to multiple antibiotics and the reduced susceptibility to the most commonly used antibiotic molecules have made the treatment of CDI more complicated, allowing the persistence of C. difficile in the intestinal environment.Gut colonization and biofilm formation have been suggested to contribute to the pathogenesis and persistence of C. difficile. In fact, biofilm growth is considered as a serious threat because of the related antimicrobial tolerance that makes antibiotic therapy often ineffective. This is the reason why the involvement of C. difficile biofilm in the pathogenesis and recurrence of CDI is attracting more and more interest, and the mechanisms underlying biofilm formation of C. difficile as well as the role of biofilm in CDI are increasingly being studied by researchers in the field.Findings on C. difficile biofilm, possible implications in CDI pathogenesis and treatment, efficacy of currently available antibiotics in treating biofilm-forming C. difficile strains, and some antimicrobial alternatives under investigation will be discussed here.

Clinical and Radiographic Outcomes of Adjunctive Photodynamic Therapy for Treating Peri-Implant Mucositis Among Cigarette Smokers and Diabetics: A Systematic Review and Meta-Analysis

Objective: This systematic review aimed to assess the influence of antimicrobial photodynamic therapy (aPDT) as an adjunct to mechanical debridement (MD) on peri-implant clinical and radiographic outcomes among cigarette smokers and diabetics with peri-implant mucositis (piM). Methods: Randomized controlled trials, assessing the clinical and radiographic parameters of aPDT versus MD alone among smokers and diabetics with piM, were included in the study. Meta-analyses were conducted to calculate the standard mean difference with a 95% confidence interval. The methodological quality of the included studies was assessed utilizing the modified Jadad quality scale. Results: The meta-analyses found statistically significant differences between the impact of adjunct aPDT and MD alone on the peri-implant plaque index (PI), probing depth (PD), and bleeding on probing among smokers and diabetics with piM at the final follow-up visit. However, no significant differences were found between the impact of adjunct aPDT and MD alone on the peri-implant crestal bone loss among smokers and diabetics with piM at the final follow-up. Conclusions: The application of aPDT as an adjunctive to MD demonstrated improved scores of the peri-implant clinical parameters among smokers and diabetics with piM in comparison with MD alone.

Antimicrobial photodynamic therapy in treatment of aggressive periodontitis (stage III, grade C periodontitis): A comparison between photodynamic therapy and antibiotic therapy as an adjunct to non-surgical periodontal treatment

BACKGROUND

Treatment of aggressive periodontitis (stage III, grade C periodontitis) represents a challenge. The aim of the study was to compare the long-term results of antimicrobial photodynamic therapy (aPDT) and antibiotic therapy as an adjunct to conventional non-surgical therapy in patients with aggressive periodontitis.

MATERIALS AND METHODS

Twenty subjects with untreated aggressive periodontitis (stage III, grade C periodontitis) were divided into two groups: the test group (TG) received non-surgical therapy and two sessions of aPDT using a laser (HELBO TheraLite laser) with a wavelength of 670 nm associated with HELBO Blue photosensitizer, and the control group (CG) received non-surgical therapy and antibiotics (amoxicillin 500 mg and metronidazole 400 mg, 7 days). Clinical parameters of probing depth, clinical attachment level and bleeding on probing (BOP) were assessed at baseline, 3, 6, 9 and 12 months after treatment.

RESULTS

The mean probing pocket depths at baseline were 3.68 mm in TG and 3.51 mm in CG. These values decreased to 2.77 mm (p < 0.05) and 2.54 mm (p < 0.05) 3 months after treatment and stayed decreased after 12 months. Clinical attachment levels at baseline were 3.88 mm in TG and 3.70 mm in CG. These values decreased to 3.06 mm (p < 0.05) and 2.80 mm (p < 0.05) after 3 months and stayed decreased after 12 months. We also found a decrease in BOP after 3, 6, 9 and 12 months in TG and in CG.

CONCLUSIONS

aPDT and antibiotics as an adjunct to non-surgical periodontal treatment lead to a comparable improvement in long term periodontal parameters.

Microbiota in Gingival Crevicular Fluid Before and After Mechanical Debridement With Antimicrobial Photodynamic Therapy in Peri-Implantitis

Objectives

This study aims to compare the microbiota of gingival crevicular fluid (GCF) before and after mechanical debridement (MD) with antimicrobial photodynamic therapy (aPDT) and determine the core efficient microbiota in peri-implantitis after treatment.

Methods

We recruited 9 patients (14 implants) treated with MD+aPDT for peri-implantitis at our center from February 1, 2018, to February 1, 2019. GCF was collected using filter paper strip before and after the treatment. The bacterial 16S rRNA was amplified and sequenced using an Illumina MiSeq platform to characterize the GCF. Bioinformatics and statistical analyses were performed using QIIME2 and R.

Results

A total of 4,110,861 high-quality sequences were obtained from GCF samples. Based on the reference database, 1,120 amplicon sequence variants (ASVs) were finally harvested. Principal coordinates analysis indicated significant differences in the bacterial community structure between the 180 days after-treatment group and pre-treatment group. Difference analysis and least discriminant analysis showed that the differences were mainly reflected in non-dominant bacteria between these two groups. The non-dominant genera with significantly different distribution between the 180 days after-treatment group and the pre-treatment group included Lactobacillus, Pedobacter, Bulleidia, Centipeda, Desulfovibrio, Ochrobactrum, Staphylococcus, Microbacterium, Brevundimonas, Desulfobulbus, and Parvimonas. Moreover, a total of 29 predictive functional categories at KEGG level 2 were identified. The significant difference pathways at KEGG level 2 between after-treatment and pre-treatment were concentrated in infectious disease-related pathways.

Conclusions

Patients with peri-implantitis have significant changes in the low-abundance bacteria of the GCF before and after MD+aPDT. MD+aPDT may change the composition of GCF microbiota by increasing the abundance of cluster 1 (beneficial) and decreasing that of cluster 4 (harmful), which may decrease metabolic response to infection and thus improve peri-implantitis.

Residual periodontal pocket treatment with Er:YAG laser-assisted comprehensive periodontal pocket therapy: a retrospective study

OBJECTIVES

Recently, the application of erbium-doped yttrium aluminum garnet (Er:YAG) laser has been increasing in periodontal therapy. In this retrospective study, we evaluated the safety and effectiveness of a novel pocket therapy using Er:YAG laser in combination with conventional mechanical scaling and root planing treatment (Er:YAG laser-assisted comprehensive periodontal pocket therapy).

METHODS

Forty sites in 29 elderly patients having residual periodontal pockets of ≥ 5 mm depth were treated by curette and Er:YAG laser from 2006 to 2009. After root debridement by curette, laser irradiation was performed on the root surfaces. Then, inflamed connective tissue on the inner gingival surface and on the bone surface/within extant bone defects was thoroughly debrided by curette and laser. Furthermore, in most cases, removal of the outer epithelium and coagulation of the blood clot in the pocket entrance were additionally performed with laser. Clinical parameters were evaluated before and 3, 6, and 12 months after treatment.

RESULTS

With Er:YAG laser-assisted pocket therapy, debridement of pockets was thoroughly and safely performed, and favorable clinical improvements were observed in most cases, without any adverse side effects and complications. After 1 year, probing pocket depth significantly decreased from 6.4 ± 1.4 to 3.5 ± 1.3 mm (p < 0.001, 3.0 mm reduction), and clinical attachment level significantly decreased from 7.5 ± 1.6 to 5.2 ± 1.9 mm (p < 0.001, 2.3 mm gain).

CONCLUSION

The results of this study indicate that Er:YAG laser-assisted therapy is useful for the treatment of residual pockets as a minimally invasive flapless surgery.

CLINICAL RELEVANCE

Er:YAG laser-assisted comprehensive pocket therapy reduces the necessity of more conventional surgical therapies.

Clinical efficacy of single and multiple applications of antimicrobial photodynamic therapy in periodontal maintenance: A systematic review and network meta-analysis

BACKGROUND

At present the clinical efficacy of single (S) versus multiple (M) applications of antimicrobial photodynamic therapy (aPDT) is controversially discussed.

AIM

To systematically evaluate the clinical efficacy of adjunctive S and M applications of aPDT to subgingival debridement (SD) in the treatment of residual periodontal pockets.

METHODS

An electronic search was carried out for randomized controlled clinical trials (RCTs) reporting on SD with the adjunctive use of S- or M-aPDT applications.

RESULTS

Statistically significantly higher improvement in bleeding on probing (BOP) and probing depth (PD) reduction was found for SD + S-aPDT versus SD, with Mean difference (MD) = -16.8 (95% CI: -30.7 to -2.91; p = 0.02) and 0.4, (95% CI: 0.02 to 0.78, p = 0.04), respectively. Regarding BOP, there was also a statistically significant difference when SD + M-aPDT was compared with SD alone, with a MD of -5.13 (95% CI: -7.20 to -3.07; p < 0.00001). For all parameters, SD + S-aPDT demonstrated the best treatment ranking of probability results, followed by SD + M-aPDT and SD alone.

CONCLUSIONS

Within their limits, the present data indicate that in periodontal patients enrolled in maintenance: a) single and multiple adjunctive applications of aPDT following SD resulted in statistically significant BOP reduction compared to SD alone, and b) repeated applications of aPDT did not seem to result in superior outcomes compared to single applications.

The stability of implants and microbiological effects following photobiomodulation therapy with one-stage placement: A randomized, controlled, single-blinded, and split-mouth clinical study

BACKGROUND

Studies have reported a positive effect on bone healing and the elimination of microorganisms placed on the titanium implants, while others have not confirmed the positive photobiomodulation therapy (PBMT) effects on bone regeneration and bone structure around the implants.

PURPOSE

The aim of the present study was to address the following questions: Does PBMT improve implant stability and affect microbiota around dental implants in the early stage of osseointegration?

MATERIALS AND METHODS

This study was designed as randomized-controlled prospective, split mouth, single-blinded clinical trial. Implants were randomly divided into two groups and implants placed in the test group were treated with Gallium-aluminum-arsenide (GaAlAs) diode laser with PBMT immediately after surgery and for 15 days (n = 47). In the control group, implants were not irradiated(n = 46). The primary stability of the implants was measured by the Resonance frequency analysis (RFA) after insertion and the secondary stability values were recorded at 30th, 60th, and 90th days after surgery as implant stability quotient (ISQ). The hand-held RFA was held perpendicular to the jaw line as indicated by the manufacturer for buccal-lingual (BL), mesial-distal (MD), and lingual-buccal (LB) measurement and different measurements were analyzed as separately.

RESULTS

Significantly higher magnetic RFA values were achieved on the 90th day in all measurement sides for both groups. ISQ levels in groups at baseline and the day-30, 60, and 90. ISQ readings were not statistically significant between test and control groups for each time point. A statistically significant increase in ISQ reading for BL, MD, and LB dimensions in both groups was noted from baseline to the day-90 (P < .05).

CONCLUSION

It was concluded that PBMT did not have a clinically significant effect on implant stabilization, especially in terms of ISQ values at early alveolar bone healing term. Clinical trial number is NCT04495335.

Synergistic Photoantimicrobial Chemotherapy of Methylene Blue-Encapsulated Chitosan on Biofilm-Contaminated Titanium

Intensive efforts have been made to eliminate or substantial reduce bacterial adhesion and biofilm formation on titanium implants. However, in the management of peri-implantitis, the methylene blue (MB) photosensitizer commonly used in photoantimicrobial chemotherapy (PACT) is limited to a low retention on the implant surface. The purpose of this study was to assess enhancive effect of water-soluble quaternary ammonium chitosan (QTS) on MB retention on biofilm-infected SLA (sandblasted, large grid, and acid-etched) Ti alloy surfaces in vitro. The effectiveness of QTS + MB with different concentrations in eliminating Gram-negative A. actinomycetemcomitans or Gram-positive S. mutans bacteria was compared before and after PACT. Bacterial counting and lipopolysaccharide (LPS) detection were examined, and then the growth of human osteoblast-like MG63 cells was evaluated. The results indicated that the synergistic QTS + MB with retention ability significantly decreased the biofilm accumulation on the Ti alloy surface, which was better than the same concentration of 1 wt% methyl cellulose (MC). More importantly, the osteogenic activity of MG63 cells on the disinfected sample treated by QTS + MB-PACT modality was comparable to that of sterile Ti control, significantly higher than that by MC + MB-PACT modality. It is concluded that, in terms of improved retention efficacy, effective bacteria eradication, and enhanced cell growth, synergistically, PACT using the 100 μg/mL MB-encapsulated 1% QTS was a promising modality for the treatment of peri-implantitis.

Effects of adjunctive light-activated disinfection and probiotics on clinical and microbiological parameters in periodontal treatment: a randomized, controlled, clinical pilot study

Objectives

The aim of this pilot study was to evaluate the clinical and microbiological outcomes of light-activated disinfection (LAD) alone or combined with probiotics as an adjunct to non-surgical periodontal treatment.

Materials and methods

In this single-blinded, randomized, controlled clinical pilot study, 48 patients (28 females and 20 males) with untreated periodontitis (stages II and III, grade B) were included. Using a parallel-group design, patients were randomly assigned into 3 groups to receive subgingival debridement (SD) alone (group 1, n = 16), SD with LAD (group 2, n = 16), or SD with LAD plus probiotic treatment (group 3, n = 16). Probing pocket depth (PPD), clinical attachment level (CAL), bleeding on probing (BOP), gingiva-index simplified (GIs), plaque-control record (PCR), and subgingival microbiological samples were analyzed at baseline, 3 months, and 6 months of follow-up.

Results

All treatment modalities demonstrated clinical improvements in PPD and CAL at 6 months compared to baseline but without a statistical significant difference between the groups. The combination of SD + LAD + probiotic treatment (group 3) demonstrated significantly greater reductions in BOP, GIs, and red complex bacteria P. gingivalis and T. forsythia compared with other groups at 6 months (p < 0.05).

Conclusions

A single application of LAD as an adjunct to SD provided no additional clinical and microbiological benefits compared to SD alone. The combination of SD + LAD + probiotic treatment in group 3 led to further improvements of the inflammatory parameters.

Clinical relevance

The additional use of probiotics in periodontal treatment can be a useful approach to support inflammation and infection control of periodontal tissues. Further studies are necessary to determine the extent of added benefit for this treatment approach.

Effectiveness of antimicrobial photodynamic therapy as an adjunct to open flap debridement in patients with aggressive periodontitis

AIM

The aim of the present clinical trial was to evaluate the clinical efficacy of photodynamic therapy (PDT) as an adjunct to open flap debridement (OFD) in the treatment of generalized aggressive periodontitis (GAP).

MATERIALS AND METHODS

The subjects recruited for the study were divided into two groups: 'control group' received treatment through OFD, whereas the test participants were treated with OFD and adjunctive PDT. The clinical periodontal parameters were plaque index (PI), full mouth probing depth (FMPD) and full mouth relative attachment loss (FMRA). The microbial levels of Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg) and Tannarella forsythia (Tf) were analyzed. All parameters were assessed at baseline and 3 months.

STATISTICAL ANALYSIS

The observed values for all the parameters were reported in mean and standard deviation (mean ± SD). In order to analyse the mean values and inter-group comparisons, the Mann-Whitney U test was employed. The p-value was set at <0.05 to establish a significant difference among the reported values.

RESULTS

A statistically significant improvement for BOP was observed in PDT group in comparison to the control group at 3 months only (p < 0.05). A significant reduction in the microbiological levels for Aa, Pg and Tf in both the study groups was observed. However, no significant differences in microbial levels were observed at any time point when the control and test groups were compared to each other.

CONCLUSION

PDT in conjuction with OFD plays a significant role in reducing the microbial load and improving the clinical periodontal parameters in patients with GAP. Moreover, it is regarded as a safe treatment regimen as no side effects have been reported regarding its use in GAP.

The effect of antimicrobial photodynamic therapy using yellow-green LED and rose bengal on Porphyromonas gingivalis

INTRODUCTION

This study aimed to investigate the effects of a new antimicrobial photodynamic therapy (aPDT) system using yellow-green light-emitting diode (YGL) and rose bengal (RB) on Porphyromonas gingivalis (Pg) in vitro.

MATERIALS AND METHODS

Pg suspension mixed with RB was irradiated with YGL (565 nm) or blue light-emitting diode (BL, 470 nm) at 428 mW/cm² in comparison with chlorhexidine (CHG) treatment. The cells were cultured anaerobically on agar plates, and the number of colony-forming units (CFU) was determined. The treated suspension was anaerobically incubated, and the cell density (OD_600nm) was monitored for 24 h. Also, the viability of treated human gingival fibroblast (HGF-1) was measured using WST-8 assay. Pg morphology was observed with a scanning electron microscope. The RNA integrity number of aPDT-treated Pg was determined and gene expressions were evaluated by quantitative real-time polymerase chain reaction.

RESULTS

RB + YGL (aPDT) demonstrated a significantly higher reduction of CFU, compared to RB + BL (aPDT) and CHG, furthermore the OD value rapidly decreased. Morphological changes of Pg with RB + YGL were more severe than with CHG. Although RB + YGL reduced HGF-1 viability, aPDT's impact was significantly lower than CHG's. With RB + YGL treatment, RIN values decreased; furthermore, gene expressions associated with DNA replication and cell division were remarkably decreased after 12 h.

CONCLUSION

The results of this study demonstrated that a novel aPDT system using RB + YGL may have potential as a new technical modality for bacterial elimination in periodontal therapy.

Transgingival photodynamic therapy (tg-aPDT) adjunctive to subgingival mechanical instrumentation in supportive periodontal therapy. A randomized controlled clinical study

BACKGROUND

Recent data from preclinical studies and case series suggest that transgingival irradiation with diode lasers may represent a novel modality for antimicrobial photodynamic therapy (aPDT). However, at present, there is lack of data from controlled clinical studies on the use of transgingival antimicrobial photodynamic therapy (tg-aPDT) in the treatment of periodontitis.

OBJECTIVE

To evaluate the clinical effects of tg-aPDT used in conjunction with nonsurgical mechanical instrumentation during supportive periodontal therapy (SPT).

MATERIALS AND METHODS

Forty stage II and III periodontitis patients enrolled in SPT were randomly assigned to two groups of equal size. At baseline, study sites had to show sites with pocket probing depth (PPD) of ≥ 5 mm and Bleeding on Probing (BOP). Full mouth and site-specific Plaque-Index scores (PI), BOP, PPD, and Clinical Attachment Level (CAL) were recorded at baseline (BL), three months (3 M), and 6 months (6 M), respectively. The primary outcome variable was the change in the number of sites with BOP. Treatment was performed under local anaesthesia after random allocation to one of the following groups 1) Subgingival scaling and root planing (SRP) + tg-aPDT (test) or 2) SRP alone (control).

RESULTS

Thirty-nine patients completed the study. Full mouth PI and BOP improved over six month, however without statistically significant difference between the groups. At 6 M, BOP-levels were statistically significantly lower in test sites (25.0 %) compared to the control sites (65.0 %), (p < 0.025). PPD improved in both groups with comparable mean values at 3 M (PPD test: 5.21 ± 0.92 mm; PPD control: 4.45 ± 1.36 mm) and 6 M (PPD test: 5.11 ± 1.10 mm; PPD control: 4.35 ± 1.14 mm). Additionally, CAL slightly improved in both groups with comparable mean values at 3 M (CAL test: 6.79 ± 1.72 mm; CAL control: 5.30 ± 2.43 mm) and 6 M (CAL test: 6.26 ± 1.70 mm; CAL control: 5.50 ± 2.33 mm).

CONCLUSIONS

Within its limits, the present results appear to indicate that the use of tg-aPDT adjunctive to SRP may represent a new modality for controlling inflammation and further bleeding in residual periodontal pockets.

Effectiveness of mechanical debridement with and without antimicrobial photodynamic therapy against oral yeasts in children with gingivitis undergoing fixed orthodontic therapy

OBJECTIVE

The aim was to assess the effectiveness of mechanical debridement (MD) and antimicrobial photodynamic therapy (aPDT) against oral yeasts in children with gingivitis undergoing fixed orthodontic therapy (FOT).

METHODS

Individuals undergoing orthodontic treatment were included. Patients were randomly divided into 2-groups. In the test-group, patients underwent MD with adjuvant aPDT; and in the control-group, patients underwent MD alone. Demographic information was recorded using a questionnaire. An ultrasonic scaler was used to perform MD and aPDT was done using methylene blue and visible light. In both groups, gingival index, unstimulated whole salivary flow rate and oral yeasts counts were measured at baseline and compared at 6-months' follow-up. Group comparisons were performed and P < 0.05 was selected as an indicator of statistical significance.

RESULTS

Eighteen (10 males and 8 females) and 18 individuals (9 males and 9 females) were included in the test- and control groups. The mean age of individuals in the test and control groups were 16.6 ± 0.5 and 16.8 ± 0.4 years, respectively. At 6-months' follow-up, the GI was comparable among patients in the test- and control-group. In the test-group, the CFU/ml of oral yeasts were significantly higher at baseline compared with 6-months' follow-up (P < 0.05). In the control-group, there was no statistically significant difference in the CFU/ml of oral yeasts at baseline and 6-months' follow-up.

CONCLUSION

aPDT is a useful adjuvant to MD in reducing whole salivary oral yeasts counts among adolescents undergoing orthodontic treatment. In the sort-term, MD with and without aPDT is useful in reducing GI in adolescents undergoing orthodontic treatment.

Commercial Local Pharmacotherapeutics and Adjunctive Agents for Nonsurgical Treatment of Periodontitis: A Contemporary Review of Clinical Efficacies and Challenges

Periodontal infections tend to be site-specific, mostly confined to the periodontal pocket. With the surge of antibiotic-resistant bacteria, the trend is shifting towards other therapeutic modalities, especially locally delivered approaches that include other pharmacotherapeutic drugs and medical devices. This narrative review aimed to provide insights into the clinical efficacy of local drug delivery and adjunctive agents used in nonsurgical management of periodontitis. Electronic (PubMed/MEDLINE, CENTRAL, and EMBASE) and bibliographic searches of past systematic reviews were carried out to identify previous publications on the topic. Only relevant literature and randomized controlled trials published in English were selected. In addition, a literature review was developed based on the selected articles. Experimental drugs or agents were excluded. This review highlights the clinically proven and commercially available therapeutic agents related to the management of periodontal disease with comparisons of their clinical efficacies and challenges. A vast array of commercial local pharmacotherapeutic agents had been clinically tested, but the methodologies and clinical results varied within and between each agent used, causing difficulty in drawing conclusions and providing support to the superiority of one agent over another. Considering the benefit-cost ratio with the modest clinical results, the long-term usefulness of these agents remains debatable.

Photoactivated disinfection in periodontal treatment: A randomized controlled clinical split-mouth trial

BACKGROUND

Photoactivated disinfection (PAD) could support the periodontal treatment outcome. The effect of the light emitting diode (LED) as an innovative light source in PAD is under discussion. The aim of this study was to evaluate the clinical and microbiological effect of adjunctive PAD in the treatment of periodontitis with a red LED as light source.

METHODS

Twenty patients with periodontitis completed this split-mouth study. The left and right side of the jaws were randomly assigned to either test or control group. After conservative periodontal treatment in both groups, the test group received two sessions of adjunctive PAD (red LED, 635 nm, photosensitive dye, 0.01% tolonium chloride), whereas the control group received no adjunctive PAD. The parameters of clinical periodontal examination-including probing depth (PD), clinical attachment level (CAL), bleeding on probing (BOP) and microbiological assays (PCR) were evaluated before and after treatment.

RESULTS

After 3 months, both treatment groups showed significant improvements regarding BOP, PD, and CAL compared to baseline, with no significant difference between control and treatment group. The recolonization of Porphyromonas gingivalis and Treponema denticola was reduced after adjuvant treatment, but not significantly.

CONCLUSIONS

The positive effect of adjunctive PAD regarding clinical parameters was reported in recent trials. In this study and with the current settings, both treatment groups showed similar clinical results after initial periodontal treatment, without beneficial effect of adjunctive PAD.

Application of Porphyrins in Antibacterial Photodynamic Therapy

Antibiotics are commonly used to control, treat, or prevent bacterial infections, however bacterial resistance to all known classes of traditional antibiotics has greatly increased in the past years especially in hospitals rendering certain therapies ineffective. To limit this emerging public health problem, there is a need to develop non-incursive, non-toxic, and new antimicrobial techniques that act more effectively and quicker than the current antibiotics. One of these effective techniques is antibacterial photodynamic therapy (aPDT). This review focuses on the application of porphyrins in the photo-inactivation of bacteria. Mechanisms of bacterial resistance and some of the current 'greener' methods of synthesis of meso-phenyl porphyrins are discussed. In addition, significance and limitations of aPDT are also discussed. Furthermore, we also elaborate on the current clinical applications and the future perspectives and directions of this non-antibiotic therapeutic strategy in combating infectious diseases.

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.

Antimicrobial photodynamic therapy - what we know and what we don't

Considering increasing number of pathogens resistant towards commonly used antibiotics as well as antiseptics, there is a pressing need for antimicrobial approaches that are capable of inactivating pathogens efficiently without the risk of inducing resistances. In this regard, an alternative approach is the antimicrobial photodynamic therapy (aPDT). The antimicrobial effect of aPDT is based on the principle that visible light activates a per se non-toxic molecule, the so-called photosensitizer (PS), resulting in generation of reactive oxygen species that kill bacteria unselectively via an oxidative burst. During the last 10-20 years, there has been extensive in vitro research on novel PS as well as light sources, which is now to be translated into clinics. In this review, we aim to provide an overview about the history of aPDT, its fundamental photochemical and photophysical mechanisms as well as photosensitizers and light sources that are currently applied for aPDT in vitro. Furthermore, the potential of resistances towards aPDT is extensively discussed and implications for proper comparison of in vitro studies regarding aPDT as well as for potential application fields in clinical practice are given. Overall, this review shall provide an outlook on future research directions needed for successful translation of promising in vitro results in aPDT towards clinical practice.

Is Antimicrobial Photodynamic Therapy Effective as an Adjunct to Scaling and Root Planing in Patients with Chronic Periodontitis? A Systematic Review

The aim of this systematic review was to investigate whether antimicrobial photodynamic therapy (aPDT) as either a primary mode of treatment or an adjunct to non-surgical treatment was more effective than scaling and root planing (SRP) alone in treating chronic periodontitis in terms of clinical attachment level (CAL) gain and probing depth (PD) reduction. The focused question was developed using the Patient, Intervention, Comparison, and Outcome (PICO) format, and two authors independently searched the Medline, EMBASE, Cochrane Library, Web of Science, Google Scholar, and Scopus databases for relevant studies from January 2008 to December 2016. Twenty studies included in this systematic review were randomized clinical trials (RCTs) or quasi-RCTs of aPDT compared to placebo, no intervention, or non-surgical treatment in an adult population. Basic study characteristics, photosensitizing agents and wavelengths used in aPDT, frequency of aPDT application, effect of aPDT on clinical parameters, antimicrobial effect of aPDT in chronic periodontitis, effect of immunological parameters following aPDT and patient-based outcome measures were collected from the studies. Although there was a wide range of heterogeneity in the included studied, they all indicated that aPDT has the potential to be an effective adjunct in the treatment of chronic periodontitis. Long-term, multicenter studies with larger sample sizes are needed before aPDT can be recommended as an effective treatment modality.

Photodvnamic Therapy in Endodontics

Commonly used irrigants do not always eradicate the entire microbial flora in infected root canals. Therefore, several other strategies, such as photodynamic therapy (PDT) have been developed. Photoactivated disinfection is based on the interaction of a photosensitive antibacterial agent and a light source. It uses a nontoxic dye named photosensitizer (PS) and low-intensity visible light. In oxygen presentation, these combine to produce some cytotoxic species. The PS molecules attach to bacteria membrane. Irradiation with a specific wavelength of the light may lead to the production of singlet oxygen, resulting in rupture of the microbial cell wall. There are several applications for PDT in dentistry. A successful periodontal treatment is based on elimination of bacteria from the infected area. Phenothiazinium PSs have been shown to be highly effective and safe for this purpose. However, scaling/root planing should be performed before the PDT. While performing the PDT, PS should be first injected in the periodontal pocket and allowed to pigment. Then, the special fiber should be inserted 1 mm short of the pocket base and lased. Photodynamic therapy has also been used to disinfect caries dentin before restoration, disinfecting oral tissues before or during surgical procedures, treating denture stomatitis, and treating oral candidiasis in immunocompromised patients. Photodynamic therapy can be used in combination with mechanical instrumentation and chemical antimicrobial agents, such as sodium hypochlo-rite, too. The purpose of this study was to review historical perspective, mechanism of action, and applications of PDT in dentistry and especially in endodontics was reviewed. Furthermore, the effects of PDT on dentin bonding and endo-toxin are discussed.

CLINICAL SIGNIFICANCE

Photodynamic therapy has been advocated to increase the disinfection level of the root canal system.

Role of mechanical curettage with and without adjunct antimicrobial photodynamic therapy in the treatment of peri-implant mucositis in cigarette smokers: A randomized controlled clinical trial

OBJECTIVE

The aim of the present 12-weeks follow-up randomized clinical trial was to investigate the outcome of mechanical curettage (MC) with or without adjunct antimicrobial photodynamic therapy (aPDT) in the treatment of peri-implant mucositis in cigarette smokers.

METHODS

Therapeutically, subjects with peri-implant mucositis were divided into 2 groups: (a) Group-A: MC+aPDT; and (b) Group-B: MC alone (control group). In both groups, peri-implant plaque index (PI), bleeding on probing (BOP) and probing pocket depth (PPD) were gauged at baseline and after 12-weeks follow-up. Group comparisons were performed using the Kruskall-Wallis test. P-values less than 0.05 were considered statistically significant.

RESULTS

Fifty-four male patients (28 in Group-A and 26 in Group-B) were included. The mean age of individuals in groups A and B were 50.6±0.8 and 52.2±0.5years, respectively. In groups A and B the participants were smoking 16.5±2.7 and 14.2±1.7 cigarettes daily since 25.2±6.5 and 24.6±4.3years, respectively. Periimplant PI, BOP and PPD were comparable among individuals in both groups at baseline. At 12-weeks follow-up, there was a significant reduction in PI (P<0.001) and PPD (P<0.001) among patients in groups A and B compared with their respective baseline values. At 12-weeks follow-up, PI (P<0.001) and PPD (P<0.001) were significantly higher among patients in Group-B compared with Group-A (P<0.001). BOP was comparable in both groups at baseline and at 12-weeks follow-up.

CONCLUSION

In cigarette smokers, MC with adjunct aPDT is more effective in the treatment of peri-implant mucositis compared with MC alone.

Efficacy of periimplant mechanical curettage with and without adjunct antimicrobial photodynamic therapy in smokeless-tobacco product users

OBJECTIVE

The aim was to investigate the effectiveness of antimicrobial photodynamic therapy (aPDT) as an adjuvant to mechanical curettage (MC) in the treatment of periimplant mucositis in smokeless tobacco (ST) product users.

METHODS

Forty-eight ST product users with periimplant mucositis were randomly divided into 2 groups. In the test-group, participants underwent periimplant MC with adjunct aPDT; and in the control-group, the patients underwent MC alone. Periimplant plaque index (PI), bleeding on probing (BOP), and probing depth (PD) were measured at baseline and after 3-months of follow-up. Statistical analysis was performed using the Kruskal-Wallis test. Level of significance was set at P<0.05.

RESULTS

At baseline, periimplant PI, BOP and PD were comparable among individuals in the test- and control groups. At 3-months follow-up, scores of periimplant PI (P<0.05), BOP (P<0.05) and PD (P<0.05) were statistically significantly higher among patients in the control-group compared with the test-group. At 3-months follow-up, the percentages of sites of PI, BOP and PD were statistically significantly higher in the control-sites as compared to the test-sites.

CONCLUSION

Among patients with periimplant mucositis, MC with adjunct aPDT is more effective in reducing periimplant inflammation in ST product users as compared to MC alone; however, the present result should be interpreted with caution as they were based on a short-term follow-up. Further long-term studies are needed in this regard.

Efficacy of periimplant mechanical debridement with and without adjunct antimicrobial photodynamic therapy in the treatment of periimplant diseases among cigarette smokers and non-smokers

OBJECTIVE

The aim was to assess the efficacy of mechanical debridement (MD) with and without adjunct antimicrobial photodynamic therapy (aPDT) in reducing periimplant inflammation among cigarette-smokers and non-smokers.

METHODS

Cigarette-smokers and non-smokers were randomly divided into 2 groups. In the test-group, participants underwent full mouth scaling and periimplant MD with adjunct aPDT; and in the control-group, the participants underwent full mouth scaling and periimplant MD alone. Periimplant bleeding on probing (BOP), probing depth (PD) and crestal bone loss (CBL) were measured at baseline and at 6- and 12-months follow-up. Statistical analysis was performed using the Kruskal-Wallis test. P-values<0.05 were considered statistically significant.

RESULTS

Eighty-four smokers (41 patients in the test group and 43 in the control group) and 82 non-smokers (40 patients in the test group and 42 in the control group) were included. Among smokers and non-smokers, periimplant PD was significantly higher in the control-group compared with the test-group (P<0.05) at 6-months of follow-up. There was no statistically significant difference in BOP, PD and CBL among smokers and non-smokers in the test- and control-groups at 12-months of follow-up. BOP was comparable among smokers at all time intervals.

CONCLUSION

In the short-term, MD with adjunct aPDT is more effective in reducing periimplant probing depth than MD alone in smokers and non-smokers. However, in the long-term outcomes of MD either with or without aPDT among smokers and non-smokers are comparable.

Effect of antimicrobial photodynamic therapy using rose bengal and blue light-emitting diode on Porphyromonas gingivalis in vitro: Influence of oxygen during treatment

Aims: A combination of rose bengal (RB) and blue LED (BL) has emerged as a new technical modality for antimicrobial photodynamic therapy (a-PDT). The purpose of this study was to clarify the influence of oxygen on the antimicrobial effect of RB + BL treatment on Porphyromonas gingivalis in vitro.Materials and Methods:P. gingivalis cells were treated with RB, BL (450-470 nm; 1 W/cm², 5 s), or RB + BL under anaerobic/aerobic conditions. Cells were incubated anaerobically, and the cell density (OD_{600 nm}) was measured after 6-48 h. Additionally, cells were cultured anaerobically on blood agar plates for 9 days, and the resulting colonies were observed. Bacterial growth within 1 h of aerobic RB + BL treatment was examined, and RNA degradation due to anaerobic/aerobic RB + BL treatment was measured after 3 h of culture. Results: Under anaerobic conditions, RB + BL significantly suppressed bacterial growth after 18 h; however, the growth after 48 h and the number of colonies after 9 days were similar to those of the untreated control. RNA degradation in the anaerobic-treatment group was not significantly different from that in the control. Under aerobic conditions, RB + BL immediately affected bacterial growth and completely inhibited growth for up to 48 h. Few colonies were detected even after 9 days of culture, and RNA was completely degraded. Conclusions: Unlike the bacteriostatic effect of anaerobic treatment, aerobic RB + BL treatment may have a bactericidal action via a-PDT effect, resulting in the destruction of RNA and bacterial cells within a short period.