Role of antimicrobial photodynamic therapy in reducing subgingival oral yeasts colonization in patients with peri-implant mucositis

Objective: The aim was to assess the role of antimicrobial photodynamic therapy (aPDT) in reducing subgingival oral yeasts colonization (OYC) in patients with peri-implant mucositis (PIM).Methods: Patients diagnosed with PIM were included. Patient demographics were recorded and implant placement and prosthetic rehabilitation protocols were retrieved from patients’ records. Peri-implant clinical parameters (modified plaque index [mPI], modified bleeding index [mBI] probing depth [PD]) and subgingival OYC and were assessed using standard techniques. All patients were randomly divided into test- and control-groups. In the test-group, patients underwent mechanical debridement (MD) of implant surfaces and supra and sub-gingival peri-implant sulci peri-implant immediately followed by a single session of aPDT. In the control-group, patients underwent MD alone. Peri-implant clinical parameters and OYC were re-assessed at 3-months’ follow-up. Sample-size estimation was done on data from a pilot investigation and group-comparisons were done using the paired t- and Mann Whitney U-tests. Correlation between age, mPI, mBI, PD and OYC at baseline and 3-months’ follow-up was assessed using regression analysis models. A statistically significant difference between the groups was recorded when P-values were less than 0.01.Results: Thirty-four individuals (17 and 17 in the test- and control groups, respectively) were included. There was no significant difference in the mean age, scores of mPI, mBI, PD and OYC among patients in the test- and control-groups at baseline. At 3-months of follow-up, there was a statistically significant reduction in scores of mPI (P<0.001), mBI (P<0.001), PD (P<0.001) and OYC (P<0.001) among patients in the test- compared with the control-groups. There was no significant correlation between age, mPI, mBI, PD and OYC in both groups.Conclusion: In the short term, a single session of aPDT as an adjunct to MD is effective in reducing peri-implant soft tissue inflammation and OYC in patients with PIM.     

Topographical changes and bactericidal efficacy of antimicrobial photodynamic therapy on titanium implant surface

BackgroundreExtensive rsearch has been done on various disinfection modalities used to achieve an aseptic implant surface. However, the bacterial efficacy and the topographical alterations resulting from the use of these techniques have never been compared.ObjectiveThis study aimed to evaluate and compare the disinfection efficacy and surface changes on a bacteria contaminated titanium block following application of various disinfectants.MethodUltrasonically cleaned titanium blocks were contaminated with Porphyromonas gingivalis and Tannerella forsythia. The infected titanium implants were randomly divided into four experimental groups and decontaminated using antimicrobial photodynamic therapy (aPDT), laser therapy, chlorhexidine and hydrogen peroxide. Bacterial viability and surface changes following decontamination were analyzed.ResultBacterial viability decreased in all the groups, with aPDT having the highest reduction. Surface roughness remained unchanged whereas the contact angle lessened in the aPDT group. Conclusion: aPDT could possibly be a suitable alternative to other disinfection regimen to treat periimplantitis.     

Effect of multiple sessions of photodynamic therapy on bone regeneration around dental implants among patients with peri‑implantitis

ObjectiveThe aim of the present study was to assess the effect of multiple sessions of antimicrobial photodynamic therapy (aPDT) on bone regeneration around dental implants among patients with peri‑implantitis.MethodsPatients with peri‑implantitis were included. Therapeutically, patients were randomly divided into 4 groups: (a) Group-I: Mechanical debridement (MD) alone; (b) Group-II: MD at baseline followed by a single session of adjunct a PDT; (c) Group-III: MD at baseline followed by aPDT at baseline and at 3-months of follow-up; and Group-IV: MD at baseline followed by aPDT at baseline and at 3- and 6-months of follow-up. Demographic data was collected and peri‑implant clinical (plaque index [PI], gingival index [GI], and probing depth [PD]) and radiographic (crestal bone loss [CBL]) parameters were assessed at baseline and after 9 months. Sample-size estimation was done on data from a pilot investigation and group comparisons were done using one-way analysis of variance and Bonferroni post-hoc adjustment tests. Level of significance was set at P<0.01.ResultsTwenty-two, 22, 22 and 22 patients with peri‑implantitis were enrolled in groups -I, -II, -III and -IV. The mean age of individuals in groups -I, -II, -III and -IV were 59.2 ± 5.3, 60.5 ± 2.8, 59.6 ± 3.1 and 58.7 ± 0.8 years, respectively. Compared with Group-I, there was a statistically significant reduction in PI (P<0.01), GI (P<0.01) and PD (P<0.01) in all groups at 9-months follow-up. There was no significant difference in PI, GI and PD in groups -II, -III and -IV at 9-months follow-up. There was no statistically significant difference in CBL in all groups at baseline and at 9-months-follow-up.ConclusionThe use of aPDT as an adjunct to MD reduces the severity of peri‑implant mucositis but does not contribute towards bone regeneration in peri‑implant osseous defects.     

The influence of implant surface roughness on decontamination by antimicrobial photodynamic therapy and chemical agents: A preliminary study in vitro

BackgroundThe aim of this preliminary study was to analyze the effectiveness of three different protocols of decontamination on five commercial moderate rough implants.Material and methodsThe types of implants investigated were: Neoporos Drive CM (CM; Neodent®), Drive CM Acqua (ACQ; Neodent®), SLActive (SLA; Straumann®), Osseotite (OT; Biomet 3i®) and Nanotite (NT; Biomet 3i®). Implant surface properties (n = 2/type of implant; control groups) were analyzed by scanning electron microscopy (SEM) images to determine surface roughness parameters (SRP) and energy disperse X-ray spectrometry to determine the chemical composition. Implants were then inoculated with Aggregatibacter actinomycetencomitans in vitro (n = 6/type of implant;experimental groups) and the contaminated areas were determined in SEM images (500x magnifications). Decontamination of implants was performed in duplicate by three protocols: antimicrobial photodynamic therapy (aPDT), EDTA associated with citric acid (EDTA + CA) and 0.12 % chlorhexidine (CHX). The remaining contaminated area (rCtA) was determined in SEM images (500x magnifications). All quantitative analysis through SEM images were analyzed in ImageJ® software for two-dimensional parameters.ResultsNo significant differences were found in SRP among implants (control group), except for Rv (lowest valley) between SLA vs. OT (p=0.0031; Kruskal Wallis post hoc Dunn). NT implants showed highest contaminated area vs. ACQ implants (68.19 % ± 8.63 % and 57.32 % ± 5.38 %, respectively; p = 0.0016, Tukey's test). SRP after decontamination showed statistical difference for Ra (arithmetical mean deviation) for all decontamination groups when compared to control (p < 0.05; ANOVA with post-hoc Tukey's multiple comparisons test), only CM implants showed statistical difference when compared decontamination protocols to control with highest modification of SRP for EDTA + AC group. For decontamination analysis, for applicability of different protocols in the same type of implant, only SLA showed statistical significant difference for aPDT vs. EDTA + CA (p = 0.0114; ANOVA with post-hoc Tukey's multiple comparisons test) with lowest rCTA for aPDT, however for ACQ implants the aPDT showed lowest rCTA with no statistical difference (p > 0.05; ANOVA with post-hoc Tukey's multiple comparisons test). No statistical difference was observed between the decontamination protocols at other implant types.ConclusionIt can be suggested that the chemical-physical characteristics of dental implants can be effected by the process of contamination and decontamination by aPDT and chemical agents.     

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

ObjectiveThe 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.MethodsCigarette-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.ResultsEighty-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.ConclusionIn 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.     

Antimicrobial efficacy and topographical alterations of photodynamic therapy versus conventional antimicrobials on contaminated zirconia ceramic in vitro

PurposeThe aim of this in vitro study was to assess the efficacy of antimicrobial photodynamic therapy (aPDT), neodymium-doped yttrium aluminium garnet (Nd:YAG) laser, and two other disinfecting agents against P. gingivalis and T. forsythia that colonized over zirconia ceramics and to evaluate if the disinfecting protocols result in zirconia surface alteration.Materials and methodsThe experiment was conducted on pre-sintered, commercially available Yttria Stabilized Zirconia (Y-TZP) ceramic blocks. The bacterial strains of P. gingivalis and T. forsythia were used to contaminate the zirconia specimens. The infected zirconia specimens were randomly divided into 4 groups (n=20/group): aPDT, Nd:YAG laser, hydrogen peroxide (H₂O₂), and chlorhexidine groups. The viability of bacteria was assayed using the MTT protocol. The surface roughness (R_a) of all zirconia specimens was estimated using a profilometer and a drop-shape analyzer was used to evaluate the contact angle using a special sessile drop method.ResultsA statistically significant reduction by the aPDT group is noticed for P. gingivalis and T. forsythia species compared to other disinfection methods (p<0.05). The second highest reduction was seen for chlorhexidine followed by Nd:YAG laser. The least reduction was demonstrated for the hydrogen peroxide group. Statistically, there was no significant difference in R_a scores between the four groups. However, the contact angles were significantly reduced from the zirconia specimens after the aPDT method which indicates a hydrophilicity increase compared to other groups. The SFE scores of all decontamination protocols from highest to lowest were aPDT (41.68), chlorhexidine (39.83), Nd:YAG (34.52), and H2O2 (29.88).ConclusionsAntimicrobial photodynamic therapy demonstrated a high antibacterial efficacy over zirconia ceramic surface without altering surface topography.     

Periodontal status and whole salivary adipokines after scaling and root planing with and without adjunct antimicrobial photodynamic therapy in obese patients with periodontitis

ObjectiveWhole-salivary (WS) adiponectin and leptin levels after scaling and root planing (SRP) with and without antimicrobial-photodynamic-therapy (aPDT) in obese and normal-weight individuals with periodontitis remain uninvestigated. This study compared the effect of SRP without and with adjuvant aPDT on periodontal status and WS leptin and adiponectin levels (LAL) in obese patients with periodontitis.MethodsGroups 1 and 2 entailed obese patients without and with periodontitis. Groups 3 and 4 had normal weight individuals without and with periodontitis. Therapeutically, individuals with periodontitis were categorized into test- (SRP+aPDT) and control- (SRP alone) subgroups. All patients without periodontitis underwent routine dental prophylaxis. Clinical attachment loss (AL), gingival and plaque index (GI and PI), probing depth (PD), missing teeth (MT) and WS LAL were measured at baseline and at three months of follow-up. P<5% were graded statistically significant.ResultsAt baseline, clinicoradiographic variables were significantly higher among patients in test- and control-groups in groups 1 (P<0.01) and 3 (P<0.01) versus 2 and 4. In group 2 and 3, LL were significantly high at baseline compared with follow-up (P<0.01). There was no difference in periodontal parameters and WS adiponectin and LL in the test and control-groups at of follow-up. No correlation existed between salivary LAL and clinical periodontal parameters (PI, GI, PD and clinical AL). No correlation existed between age, gender and BMI and WS LAL.ConclusionIn the short-term, SRP with or without aPDT is ineffective in the treatment of periodontitis in obese patients with periodontitis.     

The effect of photodynamic therapy on postoperative pain in teeth with primary endodontic infection

Introduction: The objective of this study was to investigate the action of photodynamic therapy on pain control after endodontic treatment in asymptomatic teeth with a primary infection, within a single visit.Methods: Sixty (60) single-rooted teeth with pulp necrosis and periapical lesions were selected and randomly divided into two (2) groups (n = 30), according to the protocol; a control group (CG) and a group using photodynamic therapy (aPDT). The canals were instrumented with Reciproc files # 25 up to 40 along the entire length of the canal, using 2% chlorhexidine gel as the auxiliary chemical substance, followed by irrigation with sterile saline. aPDT consited of 0.005% methylene blue as photosensitizer, using AsGaAl diode laser, 660 nm wavelength, 100 mW of power and 9 J of energy, using optical fibers with 365 μm in diameter. The canals were filled with Endomethasone N cement.Results: Pain intensity was assessed at 8, 12, 24, 48, 72 h and 1 week after endodontic treatment using a visual analogue scale. The level of pain was classified as none (0), mild (1–3), moderate (4–7) or severe (8–10). The data were at a significance level of 5%. There was a statistically significant difference (p<0.05) in the periods of 8, 12, 24, 48 and 72 h between the control group and the aPDT group. After 1 week, there was no statistically significant difference.Conclusions: It is concluded that photodynamic therapy had a significant effect on decreasing post-endodontic treatment pain in teeth with necrotic pulp and asymptomatic periapical lesions.     

Antimicrobial efficacy,optical properties and flexural strength following antimicrobial photodynamic therapy over vacuum-formed orthodontic retainers

Background and aimsVacuum-formed retainers (VFRs) are widely used in dental practices because of their superior esthetics. However, simultaneous maintenance of their hygiene, mechanical and optical properties is challenging. This study aimed to evaluate and compare the disinfection efficacy of antimicrobial photodynamic therapy (aPDT), chlorhexidine (CHX), sodium hypochlorite (NaOCl) and water over VFRs specimens, along with their effect on flexural strength and color stability.Materials and methodsFabricated VFRs of thicknesses 1 mm and 2 mm were contaminated with S. mutans and C. albicans. Brain Heart Infusion agar was used to seed Streptococcus Mutans whereas Candida Albicans was seeded in Sabourand Dextrose Agar. The contaminated retainers were divided into four groups and decontaminated using four different treatment protocols: aPDT, CHX, NaOCl and water, with 10 specimens per group. Microbial viability following decontamination, was assayed using MTT. To assess the color stability, pre and post decontamination color difference of 10 specimens was recorded using a spectrophotometer by blinding technique. The flexural strength of 10 specimens was measured using a universal testing machine by a standardized 3-point flexural strength (FS) test.ResultaPDT showed the highest reduction in the viability of S. mutans (28%) and C. albicans (20%) species in 1 mm thickness group while the second highest reduction following disinfection with CHX (40%) in followed by NaOCl disinfection (50%). On comparison between 1 mm and 2 mm, a statistically significant difference was noted for S. mutans in aPDT (p = 0.033) and NaOCl (p = 0.028) groups, and for C. albicans, a significant difference was noted within NaOCl (p = 0.001) and CHX (p = 0.043) groups. For FS, a statistically significant difference (p < 0.05) was observed between aPDT and the rest of the groups, whereas there was no statistically significant difference in the flexural strength between the CHX, NaOCl and water groups (p > 0.05) in both 1 mm and 2 mm specimens. Between 1 mm and 2 mm specimens, no statistically significant difference in the mean color difference was noted after any disinfection protocol (p > 0.05).ConclusionAntimicrobial photodynamic therapy showed a remarkable reduction in candidal and bacterial viability over VFRs. aPDT treated VFR specimens showed increased flexural strength and a higher color difference post treatment compared to other reagents.     

Short-term influence of antimicrobial photodynamic therapy as an adjuvant to mechanical debridement in reducing soft-tissue inflammation and subgingival yeasts colonization in patients with peri-implant mucositis

ObjectiveThe objective of this short-term follow-up study was to evaluate the influence of antimicrobial photodynamic therapy (aPDT) as an adjuvant to mechanical debridement (MD) in reducing soft-tissue inflammation and subgingival yeasts colonization (SYC) in patients with peri‑implant mucositis (PiM).MethodsIndividuals diagnosed with PiM were included. Demographic data was collected using a questionnaire. Peri-implant plaque index (PI), bleeding index (BI), probing depth (PD), crestal bone levels and SYC were measured at baseline. Therapeutically, these individuals were divided into test and control groups. In the control-group patients underwent MD and in the test-group patients underwent MD with adjunct single session of aPDT. Clinical peri‑implant parameters and SYC were reassessed after 12-weeks. Correlation between age, gender and duration of implants with SYC and clinical peri‑implant status was assessed using logistic regression models. P < 0.05 was selected as an indicator of statistical significance.ResultsThe test and control-groups comprised of 24 and 23 individuals, respectively. In the test and control groups, toothbrushing twice daily was reported by 7 (29.2%) and 5 (21.7%) individuals, respectively. None of the individuals had ever used a dental floss. At baseline, there was no difference in peri‑implant PI, BI, PD and CBL in the test and control groups. At follow-up, peri‑implant PI (P < 0.01), BI (P < 0.01) and PD (P < 0.01) were significantly higher in the control compared with the test-group. At baseline, SYC in the test and control groups were 1865.3 ± 403.4 CFU/ml and 1963.7 ± 512.4 CFU/ml, respectively. At 90 days’ follow-up, SYC in the test and control groups were 1472 ± 202.7 and 1538.4 ± 331.7 CFU/ml, respectively. There was no significant difference in SYC in both groups when baseline values were compared with 90 days’ follow-up.ConclusionOne session of aPDT after MC with adjunct aPDT is effective in reducing soft tissue inflammation but not SYC in patients with PiM.     

Efficacy of antimicrobial photodynamic therapy versus antiviral therapy in the treatment of herpetic gingivostomatitis among children: Aa randomized controlled clinical trial

AimThe aim of the present study was to evaluate the effect of antimicrobial photodynamic therapy (aPDT) as an adjunctive treatment to topical antiviral therapy for the treatment of children having herpetic gingivostomatitis.Materials and methods45 individuals (age group 12–18 years) with herpetic gingivostomatitis (HG) were divided into three groups on the basis of provision of treatment. (a) Group A: topical anti-viral therapy (TAT) (n = 14, mean age = 17.0 years) (b) Group B: antimicrobial photodynamic therapy (aPDT) (n = 15, mean age =17.7 years) and (c) Group C: topical anti-viral therapy + adjunctive aPDT (n = 16, mean age = 18.0 years) respectively. Pain scores [visual analogue scale (VAS) and McGill Pain Questionnaire (MPQ)] were assessed and HSV-1 was quantified. ENZYME LINKED IMMUNOSORBENT ASSAY (ELISA) was used to compute the pro-inflammatory cytokine including interleukin 6 (IL-6) and tumor necrosis factor-alpha (TNF-α). The analysis of the mean values and inter group comparisons were evaluated with the Mann-Whitney test. The Friedman test was used to establish the comparison of the changes observed in HSV quantification, pain scores, and pro-inflammatory cytokines. ANOVA tests were employed for the quantification of differences observed at follow-ups. The assessments for the clinical trial were done at baseline, immediate after post-op, two, and four weeks, and three and six months respectively.ResultsAccording to the analysis of the data obtained after the clinical assessment, the three groups reported a decrease in the pain scores, HSV-1 quantification and levels of the pro-inflammatory cytokines. However, Group C (TAT + aPDT) reported improvement in the observed parameters which was statistically significant in comparison to Group A (TAT) and Group B (aPDT) respectively.ConclusionAntimicrobial photodynamic therapy (aPDT) in conjunction with topical antiviral therapy (TAT) helped in reducing the pain scores and pro-inflammatory cytokine levels in herpetic gingivostomatitis among children.     

Does potassium iodide help in the microbial reduction of oral microcosm biofilms after photodynamic therapy with methylene blue and red laser?

ObjectiveTo evaluate the efficacy of methylene blue (MB)-mediated antimicrobial photodynamic therapy (aPDT) doped with potassium iodide (KI) against oral microcosms biofilms cultured in dentin.MethodsA saliva-glycerol stock formed from pooled human saliva was diluted in McBain artificial saliva with 1% sucrose (1:1), inoculated on bovine dentin blocks, and refreshed daily for 5 days. The biofilms were divided (n = 9/group) and treated with 0.9% NaCl (C), 0.2% chlorhexidine (CX), 0.01% MB + low-power laser 15 J, 88 mW, 180 s (PL), and 0.01% MB + 50 mM KI + laser (PKIL). Serial dilution was performed, and cellular viability (CFU/mL) was evaluated for total microorganisms, total lactobacilli, total streptococci, and S. mutans. Additional biofilms were cultured and treated (n = 4) for biomass determination (%BMR). The microscopic structure of the biofilms was observed by SEM. One-way ANOVA and Tukey tests were conducted (α=5%).ResultsTotal microorganisms and total streptococci significantly reduced in biofilms treated with CX and PKIL when compared to C, but the CX, PKIL, and PL treatments did not differ from each other. Total lactobacilli and S. mutans showed a significant reduction in the CX, PL, and PKIL groups when compared to C, but with no difference between them. Biomass analysis showed a significantly reduction for CX and PKIL compared to C. SEM micrographs showed noticeable changes in bacterial membrane integrity for the PKIL and CX groups.ConclusionThe addition of KI to methylene blue-mediated aPDT in microcosm biofilms was effective in reducing oral microorganisms, but the effect was group dependent.     

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

ObjectiveThe 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.MethodsTherapeutically, 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.ResultsFifty-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 ± 0.5 years, 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 ± 4.3 years, 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.ConclusionIn cigarette smokers, MC with adjunct aPDT is more effective in the treatment of peri-implant mucositis compared with MC alone.     

Efficacy of antimicrobial photodynamic therapy in reducing oral yeasts carriage among individuals using electronic nicotine delivery systems

Objective: The aim was to assess the efficacy of antimicrobial photodynamic therapy (aPDT) in reducing oral yeasts carriage among individuals using electronic nicotine delivery systems (ENDS).Methods: Self-reported ENDS users and non-users (individuals that reported to have never used any nicotinic product) were included. Demographic data was collected using a questionnaire. Patients were divided into 2 subgroups: (a) aPDT group; and (b) sham aPDT group. aPDT was performed using a curcumin-based photosensitizer that was exposed to a central wavelength of 660 nm and an estimated average fluency of 200 J/cm². The system delivered light by uniform diffusion for 5 min. Sham aPDT was performed using a non-activated laser tip. Oral yeasts colony forming units were determined using standard techniques. Oral yeasts were assessed at baseline and at 3-months of follow-up. Level of significance was set at P<0.05.Results: Twenty-three ENDS-users (19 males and 4 females) and 23 controls (17 males and 6 females) were included. ENDS-users were vaping for 8.3 ± 0.6 years and were using their ENDS devices 13.6 ± 2.7 times daily. Toothbrushing twice daily was reported by 8.7% and 21.7% of ENDS-users and controls, respectively. Tongue brushing was reported by none of the individuals. At baseline, oral yeasts CFU/ml were significantly higher among ENDS-users in the PDT (P<0.05) and sham PDT (P<0.05) groups compared with controls (Table 2; Figure 1). At 3-months of follow-up, CFU/ml were significantly higher among ENDS-users in the PDT (P<0.05) and sham PDT (P<0.05) groups compared with controlsConclusion: A single session of aPDT is ineffective in reducing the oral yeasts CFU/ml in ENDS-users. Further studies are needed to assess the impact of multiple sessions of aPDT in reducing the oral yeasts CFU/ml in ENDS-users.     

Rat tissue reaction and cytokine production induced by antimicrobial photodynamic therapy

BackgroundThe antimicrobial photodynamic therapy (aPDT) inactivates the target cell via reactions among the photosensitizer (PS), Laser or Led and O₂. The aim of this study was to evaluate the tissue reaction and cytokine production promoted by aPDT with curcumin photosensitizer.MethodsPolyethylene tubes containing saline solution (control), 5% sodium hypochlorite (NaOCl) and aPDT with curcumin PS 500 mg/L, were implanted into dorsal connective tissue of Wistar rats. After 7, 15, 30, 60 and 90 days of implantation, the animals were euthanized and the tubes with surrounding tissues were removed. The specimens were divided in two part, one half was processed, fixed and prepared for histological analysis by staining with hematoxylin and eosin. The other half was collected for IL-1β and IL-6 cytokine production using ELISA assay. The results were statistically analyzed by Kruskal-Wallis test followed by Dunn test (p < 0.05) for tissue reaction and ANOVA followed by Bonferroni’s correction (p < 0.05) for ELISA.ResultsAll groups showed severe tissue reactions at 7 days, whilst a significantly decrease by time was observed. Regarding to cytokine production, aPDT increases the IL-1β levels in all periods of time (p < 0.05). However, for IL-6 levels, the highest value was observed with aPDT on the 90th day (p < 0.05).ConclusionsaPDT with curcumin PS 500 mg/L demonstrated biocompatibility similar to saline solution and induced the IL-1β and IL-6 cytokines production.     

Potassium iodide enhances inactivation of Streptococcus mutans biofilm in antimicrobial photodynamic therapy with red laser

ObjectiveTo evaluate the effect of potassium iodide (KI) addition on antimicrobial photodynamic therapy (aPDT) mediated by red laser (λ = 660 nm) and methylene blue in Streptococcus mutans biofilm model.MethodsS. mutans biofilms were cultured in 96-well plates containing BHI broth with 1% sucrose for 18 h, 10% CO₂ and 37 °C and divided in groups (n = 3, in triplicate): C (NaCl 0.9%); CX (0.2% chlorhexidine); P (photosensitizer); KI (10, 25 and 50 mM); PKI (10, 25 and 50 mM); L (L1: 100 J/cm², 9 J; L2: 200 J/cm², 18 J); PL (photosensitizer + L1 or L2); KIL (KI at 10, 25 and 50 mM + L1 or L2); and PKIL (photosensitizer + 10, 25 and 50 mM KI + L1 or L2). Biofilms were submitted to three pre-irradiation (PI) times (5, 10, and 15 min). After the treatments, microbial counting's reduction was analyzed by Kruskal-Wallis and post-hoc Dunn's tests, respectively, and the interaction between light parameters and the PI times by two-way ANOVA (p < 0.05).ResultsThe S. mutans viability significantly reduced in all aPDT groups, in the presence or absence of KI (p < 0.05). For all PI times, PKIL groups (10, 25, and 50 mM) significantly differed from PL groups (p < 0.05) with a reduction of 9.0 logs reached at 50 mM of KI with 15 min of PI, irradiated at 18 J. We found no significant interaction between PI time and irradiation (p > 0.05).ConclusionThe addition of KI to PDT mediated by methylene blue and red laser promoted an additional effect in reducing the microbial viability of S. mutans biofilm.     

Efficacy of periimplant mechanical debridement with and without adjunct antimicrobial photodynamic therapy in patients with type 2 diabetes mellitus

ObjectiveThere are no studies that have assessed the efficacy of mechanical debridement (MD) with and without adjunct antimicrobial photodynamic therapy (aPDT) in the treatment of periimplant inflammation in patients with type 2 diabetes mellitus (T2DM). The aim of the present 12-month follow-up study was to assess the efficacy of MD with and without adjunct aPDT in the treatment of periimplant inflammation in patients with T2DM.MethodsSixty-seven patients with diagnosed periimplant inflammation and T2DM were included. Treatment-wise, the patients were divided into 2 groups: (a) test-group (n = 34): patients receivedMD+ aPDT; and (b) control group (n = 33): patients received MD only. Periimplant bleeding on probing (BOP), probing depth (PD) ≥4 mm and mesial and distal marginal bone loss (MBL) were measured at baseline and after 6 and 12 months of therapy in both groups. The Kruskal-Wallis test was used to compare the periimplant BOP, PD, MBL and HbA1c levels in both groups. P-values less than 0.05 were considered statistically significant.ResultsMean preoperative hemoglobin A1c (HbA1c) for patients in the control group and test group were 8.5% and 8.8%, respectively. In the control group, there was no significant difference in HbA1c levels at all follow-up durations. Among patients in test group, there was a significant decrease (P < 0.05) in HbA1c levels at 6 and 12 months of follow-up. Both PD and BOP were significantly lower in the test group compared to the control group at all follow-up durations. At 6 and 12 months of follow-up, there was no significant difference in MBL in both groups.ConclusionIn patients with T2DM, MD with adjunct aPDT is more effective in the treatment of periimplant inflammation compared with MD alone.     

Adjunctive therapies for in vitro carious lesions: Antimicrobial activity,activation of dentin metalloproteinases and effects on dental pulp cells

BackgroundAdjunctive therapies used before dental restorative procedures may encourage carious tissue removal. Beyond promising antimicrobial properties, treatments could positively modulate the dentin-pulp complex while not interfering with restoration survival. Herein, we evaluated a set of substances and their effects on carious lesions and the underlying dentin or pulp cells.MethodsArtificial caries lesions were developed in bovine teeth cavities immersed in Streptococcus mutans and Lactobacillus casei co-cultures. The cavities were treated according to the following groups: Phosphate Buffer Saline (PBS), Chlorhexidine (CHX), Papacárie® (Papain gel), Ozone (O₃), and antimicrobial Photodynamic Therapy (aPDT). After treatments, samples were cultivated to count isolated microbial colonies. The zymography assay evaluated the activity of dentin metalloproteinases (MMP-2 and MMP-9). Cell viability was indirectly assessed on human dental pulp cells after 24, 72, or 120 h, whereas the odontodifferentiation potential was evaluated after ten days of cell culture.ResultsCHX and aPDT led to around 1 log bacterial load reduction. PBS, CHX, and aPDT showed the eventual expression of MMP-2 and MMP-9. Cell viability was reduced (< 30%) after 120 h for all groups compared to the control. CHX, O3, and aPDT induced greater odontodifferentiation (≈ 20% higher) than PBS and papain gel.ConclusionAdjunctive therapies presented little or no biological significance in reducing bacterial load in artificial carious lesions. Although the activation of endogenous metalloproteinases may represent a possible concern for adhesive restorations, some of these treatments may have a positive role in dental pulp tissue repair.     

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

ObjectiveThe 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.MethodsForty-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.ResultsAt 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.ConclusionAmong 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 curcumin-mediated antibacterial photodynamic therapy for oral antisepsis: A systematic review and network meta-analysis of randomized clinical trials

BackgroundThe presence of oral microorganisms resistant to traditional treatment is increasing, thus a search for new therapies is needed. In this context, antimicrobial photodynamic therapy (aPDT) is an approach for the treatment of antibiotic resistant andnon resistant microorganisms. Therefore, the aim of the present study was to conduct a systematic review and meta-analysis of randomized clinical trials of aPDT for oral antisepsis against oral polymicrobial biofilms.MethodsPubMed, Science Direct, Scopus, SciELO, Lilacs, Cochrane Library and Embase databases were searched. In total, five articles were included for qualitative analysis and four articles were used for quantitative analyses. Bias assessment of the eligible articles was made using the RoB 2 criteria. Network meta-analysis was performed using the random-effect model. Subgroup's analysis was also conducted. The groups evaluated were aPDT, exposure to light only and no treatment at all (control group). The quality of evidence was assessed by CINeMA approach.ResultsaPDT mediated by curcumin had significant results in the reducing bacterial load (0.31–0.49 log₁₀ UFC/ I²=0%) when compared with the control group. The included articles were classified as low risk of bias, despite biases detected by allocation and blinding. Moreover, quantitative analysis between aPDT and control group and between light and control group were classified with low risk of confidence rating, while the results from aPDT versus light were classified as moderate risk of confidence rating.ConclusionaPDT has significant efficacy for oral antisepsis, however more randomized clinical trials will be needed to validate the present results.