Clinical efficacy of photodynamic therapy and laser irradiation as an adjunct to open flap debridement in the treatment of chronic periodontitis: A systematic review and meta-analysis

Comparative effects of the conventional, ultrasonic, and laser-activated irrigation on penetration depth of three photosensitizers in the root canal system

OBJECTIVES

This study compared the effects of conventional, ultrasonic, and laser-activated irrigation (LAI) on penetration depth of three photosensitizers (PSs) in the root canal system.

MATERIALS AND METHODS

In this in vitro, experimental study, 120 extracted anterior teeth were decoronated such that the remaining root length was standardized at 12 mm. After root canal instrumentation with the ProTaper rotary system and irrigation with 5.25% NaOCl, the roots were assigned to 12 groups for the application of toluidine blue (TB), curcumin, and phycocyanin PSs combined with the LAI using erbium laser with 0.4 mm and 0.6 mm tips, ultrasonic activation, and conventional irrigation. The specimens were sectioned apicocoronally, and the dye penetration depth was quantified in the coronal, middle, and apical thirds under a stereomicroscope at x20 magnification. Data were analyzed by the Kruskal-Wallis and Dunn test (alpha=0.05).

RESULTS

The effects of irrigation technique, PS type, and their interaction on dye penetration depth were significant at the apical, middle, and coronal thirds (P < 0.0001). TB + LAI with 0.4- and 0.6-mm laser tips showed the highest penetration depth while phycocyanin + LAI or conventional irrigation showed the lowest penetration depth at all areas. Dye penetration depth was the highest in the coronal, and the lowest in the apical third.

CONCLUSION

The LAI technique with erbium laser (0.4- and 0.6-mm tips) enhanced the penetration depth of TB. The tested irrigation techniques had no significant efficacy for enhancement of the penetration depth of curcumin and phycocyanin.

Conditioning of PEEK Implant Abutment Surfaces Using Photodynamic Therapy, Nd:YAG Laser, and Conventional Methods to Evaluate Shear Bond Strength

Objective: This study was done to evaluate shear bond strength (SBS) and modes of failures after different surface treatment modalities on polyetheretherketone (PEEK) implant abutments. Materials and methods: Seventy-five PEEK implant abutment specimens were randomly distributed into five groups based on surface treatment methods: Group I: No treatment, Group II: methylene blue-mediated photodynamic therapy (MB-PDT), Group III: neodymium-doped yttrium aluminum garnet (Nd:YAG) laser, Group IV: Sulfuric acid (H2SO4), and Group V: Sandblasting (Sb). The measurements for SBS and failure modes for PEEK implant abutment specimens were evaluated via Universal Testing Machine and Stereomicroscope, respectively. Two-way analysis of variance and Tukey's post-hoc test (p > 0.05) were used for the statistical analysis. Moreover, the Shapiro-Wilk normality test was also performed for normality. Results: The SBS mean values and standard deviations in megapascals (MPa) for PEEK abutment specimens with different surface pretreatment groups are shown in Table 1 and Fig. 1. The control group had the lowest SBS (9.67 ± 2.1 MPa), while the highest SBS was observed in Group II (MB-PDT; 17.21 ± 1.32 MPa). SBS values for Group IV (H2SO4; 15.83 ± 0.63 MPa) and Group III (Nd:YAG laser; 16.91 ± 2.10 MPa) were similar to Group II (MB-PDT; p > 0.05). The SBS values for the sandblasted specimens (13.90 ± 1.87 MPa) were not significantly different from the control group (p > 0.05). Conclusions: The PEEK implant abutment surfaces treated with MB-PDT and Nd:YAG laser expressed significantly improved SBS.

Clinical, Bacterial, and Prosthodontic Parameters After Implant Abutment Disinfection Using Nd:YAG, Er,Cr:YSGG, Chlorhexidine, and Conventional Steam Before Prosthesis Delivery

Objective: This 1-year prospective clinical trial was designed to assess the microbial, clinical, radiographic, and prosthetic parameters after disinfection of the implant abutment connection using Er,Cr:YSGG (erbium, chromium-doped: yttrium, scandium, gallium, and garnet) and Nd:YAG (neodymium-doped yttrium, aluminum, garnet). Materials and methods: All the patients were divided into four groups; Group I: Nd:YAG laser, Group II: Er,Cr:YSGG laser, Group III: 0.2% chlorhexidine (CHx), and Group IV: steam disinfection. Peri-implant parameters assessed included peri-implant bleeding scores (PIBS), peri-implant plaque scores (PIPS), peri-implant pocket depth (PIPD), and crestal bone loss (CBL). The peri-implant plaque samples were acquired to perform microbiological analysis to assess Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia, respectively. All measurements were completed at baseline, 6 months, and 12 months postsurgery. Multiple groups were compared with the help of the Bonferroni post-hoc adjustment test (p < 0.01). Logistic regression models were utilized to assess the association between age, oral hygiene practices (brushing and flossing), and duration of implant function. Results: At the baseline level, there were no discernible differences in the peri-implant parameters between the study groups (p > 0.05). At the 6-month (p < 0.01) and 12-month (p < 0.001) follow-ups, all four study groups demonstrated a significant improvement in PIPS and PIBS, with no significant differences between the groups at baseline (p > 0.05). Based on an intergroup comparison, Group I (Nd:YAG) showed a significant decrease in PIBS when compared with the other groups. Group II showed a considerable decrease in PIPD and enhancements in CBL when compared with Groups I, III, and IV (p < 0.01). At the 6- and 12-month follow-up periods, P. gingivalis and T. denticola reduction were found to be statistically higher in Group II, whereas P. gingivalis and T. forsythia mean log CFU/mL were found to be statistically higher in Group I. Conclusions: Nd:YAG and Er,Cr:YSGG lasers both outperformed CHx and steam disinfection in terms of clinical, peri-implant, and prosthetic results when used to clean implant abutments.

Application of Different Wavelengths of LED Lights in Antimicrobial Photodynamic Therapy for the Treatment of Periodontal Disease

Therapeutic light has been increasingly used in clinical dentistry for surgical ablation, disinfection, bio-stimulation, reduction in inflammation, and promotion of wound healing. Photodynamic therapy (PDT), a type of phototherapy, has been used to selectively destroy tumor cells. Antimicrobial PDT (a-PDT) is used to inactivate causative bacteria in infectious oral diseases, such as periodontitis. Several studies have reported that this minimally invasive technique has favorable therapeutic outcomes with a low probability of adverse effects. PDT is based on the photochemical reaction between light, a photosensitizer, and oxygen, which affects its efficacy. Low-power lasers have been predominantly used in phototherapy for periodontal treatments, while light-emitting diodes (LEDs) have received considerable attention as a novel light source in recent years. LEDs can emit broad wavelengths of light, from infrared to ultraviolet, and the lower directivity of LED light appears to be suitable for plaque control over large and complex surfaces. In addition, LED devices are small, lightweight, and less expensive than lasers. Although limited evidence exists on LED-based a-PDT for periodontitis, a-PDT using red or blue LED light could be effective in attenuating bacteria associated with periodontal diseases. LEDs have the potential to provide a new direction for light therapy in periodontics.

Advances in antimicrobial hydrogels for dental tissue engineering: regenerative strategies for endodontics and periodontics

Dental tissue infections have been affecting millions of patients globally leading to pain, severe tissue damage, or even tooth loss. Commercial sterilizers may not be adequate to prevent frequent dental infections. Antimicrobial hydrogels have been introduced as an effective therapeutic strategy for endodontics and periodontics since they have the capability of imitating the native extracellular matrix of soft tissues. Hydrogel networks are considered excellent drug delivery platforms due to their high-water retention capacity. In this regard, drugs or nanoparticles can be incorporated into the hydrogels to endow antimicrobial properties as well as to improve their regenerative potential, once biocompatibility criteria are met avoiding high dosages. Herein, novel antimicrobial hydrogel formulations were discussed for the first time in the scope of endodontics and periodontics. Such hydrogels seem outstanding candidates especially when designed not only as simple volume fillers but also as smart biomaterials with condition-specific adaptability within the dynamic microenvironment of the defect site. Multifunctional hydrogels play a pivotal role against infections, inflammation, oxidative stress, etc. along the way of dental regeneration. Modern techniques (e.g., 3D and 4D-printing) hold promise to develop the next generation of antimicrobial hydrogels together with their limitations such as infeasibility of implantation.

Effectiveness of photodynamic therapy on clinical and biomarker related periodontal parameters and oral health related quality of life (OHRQoL) in Parkinson's disease patients with stage III periodontitis

AIMS

To evaluate the clinical, radiographic, immune modulatory biomarkers and quality of life with the application of photodynamic therapy (PDT) as an adjunctive treatment to dental scaling and root planing (SRP) in patients with chronic periodontitis and Parkinson's disease.

METHODOLOGY

Individuals who had a confirmed diagnosis of stage III periodontitis and stage 4 Parkinson's disease according to Hoehn and Yahr scale were involved in this study. The participants were divided into two groups: Group SRP (n = 25) received traditional dental scaling procedure including full-mouth debridement and disinfection, and Group PDT + SRP (n = 25) received both traditional cleaning procedures along with adjunctive chloro‑aluminum phthalocyanine (CAPC) gel (0.005% concentration) mediated PDT. CAPC photosensitizer was activated using a diode laser (wavelength=640 nm, energy=4 J, 150 mW power, and overall power density of 300 J/cm2) for 60 s. The study measured clinical parameters such as plaque score (PI), bleeding on probing (BOP), probing depth (PD), clinical attachment loss (CAL), and radiographic alveolar bone loss (ABL). Proinflammatory cytokine levels such as interleukin (IL)-6 and tumor necrosis factor alpha (TNF-α) and oral health related quality of life were also assessed.

RESULTS

The mean age of patients in Group SRP was 73.3 years, while the mean age in Group PDT + SRP was 71.6 years. The PDT + SRP group showed a significant reduction in all clinical parameters at 6 and 12 months compared to the SRP group alone (p < 0.05). IL-6 and TNF-α levels were significantly reduced in the PDT + SRP group at 6 months compared to the SRP group alone (p < 0.05). However, at 12 months, both groups showed comparable TNF-α levels. The results showed that Group PDT + SRP had significantly lower OHIP scores compared to Group SRP, with a mean difference of 4.55 (95% confidence interval [CI]: 1.98 to 7.12) (p < 0.01).

CONCLUSION

Combined SRP with PDT showed significant improvement compared to SRP alone in terms of clinical parameters, cytokine levels, and oral health-related quality of life in individuals diagnosed with stage III periodontitis associated with Parkinson's disease.

Chloro-aluminum phthalocyanine-mediated photodynamic therapy improves peri-implant parameters and crevicular fluid cytokine levels in cigarette smokers with chronic hyperglycemia

PURPOSE

This clinical trial aimed to evaluate the effectiveness of chloroaluminum phthalocyanine-mediated photodynamic therapy (CAPC-PDT) as an adjunct to peri-implant mechanical debridement (PID) in the treatment of peri-implantitis in patients with chronic hyperglycemia and cigarette smoking.

METHODS

The selected participants with peri-implantitis were divided into two groups: Group I (n=15) included hyperglycemic patients with no history of smoking and Group II (n=15) included hyperglycemic patients with a history of smoking cigarettes. Both groups were further divided into two subgroups based on the type of therapy provided: PDT+PID and PID alone. Peri-implant bleeding on probing (PiBOP), peri-implant pocket depth (PiPD), peri-implant plaque scores (PiPS), and crestal bone loss (CBL) were assessed. Peri-implant crevicular fluid (PICF) was sampled for quantification of interleukin (IL)-1β and tumor necrosis factor-alpha (TNF-α) using an enzyme-linked immunosorbent assay. All assessments were performed at baseline and at three and six months.

RESULTS

PDT+PID showed a higher reduction in PiBOP than PID alone in hyperglycemic/non-smoking participants (p<0.01). PDT+PID and PID show a significant reduction in PiBOP in smokers only at 6 months (p<0.05), with comparable differences between PDT+PID and PID (p>0.05). PDT+PID significantly reduced PiPD hyperglycemic/smoking patients at 3 and 6 months (p<0.05), whereas PID only produced a significant reduction in PiPD at 6 months in smoking patients (p<0.05). CBL alone with PDT+PID in both smokers and non-smokers showed a statistically significant reduction at 6 months follow-up (p<0.05). IL-1β was significantly reduced in hyperglycemic/non-smoking participants at 6 months follow-up with both PDT+PID and PID alone (p<0.01). This trend was also observed in cigarette smokers, with an additional short-term reduction in IL-1β at 3 months with PDT+PID (p<0.05). Only the PDT+PID group showed a significant reduction in TNF-a among cigarette smoking patients with chronic hyperglycemia at 6 months follow-up (p<0.05) CONCLUSION: Chloroaluminum phthalocyanine-mediated PDT proved effective in improving peri-implant clinical outcomes and reducing cytokine levels in smoking patients with chronic hyperglycemia.

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.

Efficacy of curcumin-mediated photodynamic therapy for root canal therapy procedures: A systematic review

BACKGROUND

This systematic review aimed to investigate the effectiveness of CUR-mediated PDT (Curcumin mediated PDT) as an adjunct to conventional chemo-mechanical debridement and/or standard PDT of the RC system with endodontic infections.

METHODS

The focused research question was: "Whether the application Curcumin mediated PDT as an adjunct is more effective than the traditional chemo-mechanical debridement and/or standard PDT of the RC system alone for improving antibacterial and/or mechanical features among subjects undergoing RCT?". An electronic literature search was performed in Scopus, PubMed, and Web of Science. In vitro reports utilizing Curcumin mediated PDT as an adjunct to conventional chemo-mechanical debridement considering permanent dentition assessing the antibacterial and/or mechanical effect were included.

RESULTS

Eighteen articles were included in the review, out of which 13 studies assessed the antibacterial activity, while 5 evaluated the mechanical properties. Most of the studies concluded that Curcumin mediated PDT had a significant antibacterial activity than the conventional chemo-mechanical debridement and/or standard PDT. Four of the five studies suggested that Curcumin mediated PDT had no impact on the push-out bond strength of root dentin. Furthermore, the significant heterogeneity in the data from the included studies did not permit the author to carry out a meta-analysis.

CONCLUSION

There is potential for application of Curcumin mediated PDT as an adjunct to the conventional chemo-mechanical debridement and/or standard PDT in reducing the bacterial load, however, Curcumin mediated PDT has minimal effect on enhancing the pushout bond strength of fiber posts to radicular dentin. Moreover, clinical studies are required to provide a more conclusive opinion on the efficacy of Curcumin mediated PDT for RCT procedures.

Novel use of chloro-aluminum phthalocyanine assisted photodynamic therapy helps in periimplant healing among smoking patients

AIMS

To evaluate the clinical and biochemical peri‑implant parameters using chloro‑aluminum phthalocyanine-(CAP) mediated antimicrobial photodynamic therapy (PDT) as an adjunct to non-surgical mechanical debridement (NSD) in cigarette smokers (CS) and never-smokers (NS) with peri‑implantitis.

MATERIALS AND METHODS

Thirty-two patients with peri‑implantitis [Group CS - 16 and Group NS - 16] were recruited for the trial. The study participants underwent two therapies: PDT + NSD and NSD alone. The clinical peri‑implant parameters assessed in this clinical trial were bleeding on probing (BP), crestal bone loss (CBL) peri‑implant pocket depth (PD), and peri‑implant plaque scores (PS), respectively. Peri-implant crevicular fluid was sampled and the quantification of interleukin (IL)-1β and tumor necrosis factor-alpha (TNF-α) was performed using enzyme linked immunosorbent assay (ELISA).

RESULTS

BP was significantly reduced at 6 months after PDT+NSD in CS groups. Mean PD significantly reduced after both PDT+NSD and NSD subgroups within both NS and CS groups. Only at 6 months did PDT+NSD showed statistically significantly reduced IL-1β levels in the NS group. TNF-α levels significantly reduced in CS group with PDT+NSD and NSD alone at both 3 months and 6 months follow up.

CONCLUSION

CAP-assisted PDT helped to improve the clinical and cytokine levels after non-surgical peri‑implant mechanical debridement in treating peri‑implantitis patients in smokers.

Antimicrobial photodynamic therapy using chloro-aluminum phthalocyanine for treating advanced stage-III periodontitis in smoking patients

PURPOSE

To evaluate the bacterial, clinical, and cytokine profile of adjunctive photodynamic therapy using chloro-aluminum phthalocyanine (CAP/aPDT) with root surface debridement (RSD) versus RSD alone in cigarette smokers (CS) and never-smokers (NS) during the period of 6 months.

METHODS

Twenty-nine patients [CS - 14 and NS - 15] were recruited for the trial having stage-III periodontitis. All candidates from the study groups were subjected to a split-mouth treatment technique receiving CAP/aPDT + RSD and RSD alone. Periodontal parameters including plaque levels (PL), bleeding on probing (BP), probing depth (PD), clinical attachment loss (CAL), and marginal bone loss (MBL) were assessed. Polymerase chain reaction (qPCR) assay was used to analyze the copy numbers of Porphyromonas gingivalis (Pg) and Tannerella forsythia (Tf). Levels of tumor necrosis factor-alpha (TNF-α) interleukin (IL)-6 in the crevicular fluid were evaluated by enzyme-linked immunosorbent assay (ELISA).

RESULTS

CAP/aPDT+RSD decreased BP in smokers after 6 months (p < .05). Probing depth and CAL reported statistically significant reductions within both CAP/aPDT+RSD and RSD groups and also within the NS and CS (p < .05). Pg and Tf stayed elevated in smokers at the 6-month evaluation period (p < .01). Only CAP/aPDT+RSD significantly decreased Pg and Tf at 3- and 6-month follow-up in smokers (p < .05). CAP/aPDT+RSD showed decreased IL-6 levels in the NS during the 6-month follow-up (p < .01). TNF-α levels were significantly reduced in the CS group with CAP/aPDT+RSD and RSD alone until 6 months (p < .01).

CONCLUSION

CAP-mediated aPDT along with nonsurgical periodontal therapy helped to improve the bacteriological outcomes among smokers and never-smokers with stage-III CP patients.

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

AIM

The 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 METHODS

45 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.

RESULTS

According 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.

CONCLUSION

Antimicrobial 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.

Detection of invisible dental biofilm using light-induced autofluorescence in adult patients-A systematic review

BACKGROUND

Autofluorescence (AF) spectroscopy is a potent yet non-invasive technique with diagnostic and therapeutic applications. It identifies and characterizes changes occurring in the human body based on the changes in the fluorescence signatures.

AIM

The primary purpose of this systematic review is to address the question "Is it feasible to detect dental plaque using light-induced auto-fluorescence in adult patients with invisible grade 1 plaque?"

MATERIALS AND METHODS

The literature search was conducted independently MEDLINE, Embase, Cochrane Library, Web of Science, Google Scholar, and Scopus databases for relevant studies from January 2000 and June 2021, using the following terms in various combinations: detection, dental biofilm, plaque, light, auto-fluorescence, caries, gingivitis, sensitivity and specificity. Studies describing various fluorescence techniques for the detection of plaque, including sensitivity and specificity, were included.

RESULTS

The majority of the studies indicated that AF spectroscopy allows fluorescence-based detection of various diseases, including early-stage dental plaque. While results of conventional plaque detection techniques are inconsistent, the data from the AF technique is reliable and reproducible, which can be used for patient documentation. However, a wide range of non-uniformity existed in these studies. AF spectroscopy, as a non-invasive technique, represents a viable and patient-friendly clinical tool for the early detection of dental biofilm plaque, and its meticulous removal has been directly responsible for the prevention of this disease.

CONCLUSION

Despite the heterogeneity and limitations of studies included in this review, the future for light-induced autofluorescence spectroscopy technologies in diagnostic dentistry certainly presents an accurate and potentially applicable option.

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

BACKGROUND

reExtensive 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.

OBJECTIVE

This study aimed to evaluate and compare the disinfection efficacy and surface changes on a bacteria contaminated titanium block following application of various disinfectants.

METHOD

Ultrasonically 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.

RESULT

Bacterial 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.

Clinical and bacterial outcomes of photodynamic therapy in the treatment of chronic necrotizing ulcerative periodontitis

AIM

To assess the clinical periodontal and microbiological parameters in patients having chronic necrotizing ulcerative periodontitis (NUP) after the administration of adjunctive photodynamic therapy and non-surgical periodontal therapy in smokers, mal-nutrition and HIV positive individuals.

MATERIALS AND METHODS

A total of 30 individuals with NUP were selected for the present clinical trial, where both Group I and Group II had equal number of patients respectively (15 each). The groups were divided on the basis of provision of treatment where patients in Group I underwent scaling and root planing (SRP). Furthermore, Group II patients were subjected to adjunctive phtotodynamic therapy and SRP (aPDT + SRP). Full mouth plaque scores (fmpS), full mouth bleeding on probing (fmBOP), periodontal pocket depth (PPD) and clinical attachment levels (CAL) were the clinical periodontal parameters that were carefully evaluated. Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg) and Tannerella forsythia (Tf) were the bacteria species which were evaluated. The assessments were done at baseline, three (3) months and six (6) months respectively.

RESULTS

All periodontal parameters including fmpS, fmBOP, PPD and CAL significantly improved in both Group I and Group II respectively. Group II patients subjected to aPDT + SRP reported higher reduction in mean PPD in comparison to Group I patients at follow up (p<0.05). At follow-up, similar results were also reported for CAL gain where Group II (aPDT +SRP) patients reported higher CAL gain in comparison to patients who underwent SRP only (p<0.05). From baseline to follow-up, all the bacterial levels exhibited reduction in both study groups i.e Group I (SRP) and Group II (aPDT + SRP) respectively (p<0.05). However, Group II patients prominent reduction in the counts of Aa and Tf at the three-month interval, whereas Aa seem to reduce in HIV and smoking individuals at the six-month interval. Moreover, the levels of Pg and Tf significantly reduced at 3 months and only Aa at 6 months in patients with mal-nutrition respectively (p<0.05).

CONCLUSION

The use of photodynamic treatment as an adjunct to scaling and root planing enhanced clinical periodontal results and reduced bacterial content in patients having NUP.

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

BACKGROUND AND AIMS

Vacuum-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 METHODS

Fabricated 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.

RESULT

aPDT 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).

CONCLUSION

Antimicrobial 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.

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

PURPOSE

The 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 METHODS

The 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 (Ra) 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.

RESULTS

A 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 Ra 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).

CONCLUSIONS

Antimicrobial photodynamic therapy demonstrated a high antibacterial efficacy over zirconia ceramic surface without altering surface topography.

Photodynamic therapy and photobiomodulation therapy in zoledronic acid-induced osteonecrosis in rats

BACKGROUND

This study investigated the effect of antimicrobial photodynamic therapy (PDT), using methylene blue (MBO) and photobiomodulation therapy (PT), on the alveolar bone of rats submitted to bisphosphonate-induced osteonecrosis of the maxillaries (OMB) model using zoledronic acid (ZA).

METHODS

Sixty rats divided into six groups were used: SALINE, PDT, ZA, ZA+PDT, ZA+PT, and ZA+MBO. Three weekly administrations (Days 0, 7, and 14) of ZA 0.20 mg/kg or saline solution were performed. After one month (Day 42), the exodontia of the left lower first molars were performed. An additional dose of ZA was administered at Day 49. PDT was performed on days 42, 45, 49, and 54. One month after exodontia (Day 70), the animals were euthanized to obtain samples for imaging and microscopic analysis. ANOVA/Bonferroni tests were used for statistical analysis.

RESULTS

The ZA+PDT group showed a significantly lower percentage of apoptotic osteocytes than the ZA group (p<0.001). The ZA+MBO, ZA+PT, and PDT groups significantly reduced the number of mononuclear cells compared to the ZA group (p<0.001). The ZA+PT and ZA+PDT groups showed a significant reduction in the number of CD 68+ (p<0.001) and CD3+ (p=0.002) cells compared to the ZA group. The number of cells expressing INF-y had a significant reduction in the groups co-treated with PT and PDT compared to the ZA group (p<0.001).

CONCLUSIONS

We conclude that PDT and PT attenuated the severity of OMB and the inflammatory process due to a reduction of macrophages, T lymphocytes, and cytokines that stimulate the activity of these cells.

Assessment of peri-implant parameters clinical and radiographic in obese and non-obese along with destructive pro-inflammatory cytokines IL-1β - and IL-6 treated with Photodynamic therapy

AIM

The present study aims to compare and evaluate radiographic and clinical parameters along with salivary proinflammatory cytokine profiles (IL-1β - and IL-6) in obese with peri-implantitis.

MATERIAL AND METHODS

Obese and non-obese participants in the present study were 80. The nonobese and obese participants were scrutinized based on inclusion and exclusion criteria. All participants both obese and non-obese were subjected to full mouth mechanical debridement (MD). A single session of Photodynamic therapy (PDT) was provided to all obese participants. Clinical peri-implant parameters peri-implant plaque index (PIPI), Peri-implant bleeding on probing (PIBoP), peri-implant probing depth (PIPD) were assessed at baseline, three months, and six months. Marginal bone loss (MBL) was also assessed. Enzyme-linked immunosorbent assay (ELISA) was used to check the levels of IL-1β - and IL-6 in unstimulated whole saliva samples. All the parameters were assessed using the Kruskal Wallis test and analysis of variance (ANOVA). Overall characteristics were assessed using descriptive statistics. SPSS software was used for statistical analysis.

RESULTS

Clinical baseline periodontal parameters PIPI, PIBoP, PIPD, and MBL in non-obese participants were significantly lower compared to group I obese participants at baseline (p < 0.05). At 3 months follow-up PDT adjunct to MD in group 1 obese participants PIPI and PIPD were significantly lower compared to MD alone in non-obese participants PIP1 and PIPD. At 6 months follow up, non-obese participants with peri-implantitis treated with MD demonstrated PIPI and PIPD significantly lower compared to obese participants treated with PDT adjunct to MD CONCLUSION: : PDT adjunctive to MD enhanced periodontal parameters i.e., peri-implant probing depth, peri-implant plaque index, and peri-implant bleeding on probing in obese with peri-implantitis. Moreover, obese individuals with peri-implantitis demonstrated high levels of proinflammatory cytokines IL-1β and IL-6 than control.

Peri-implant parameters and cytokine profile among Peri-implant disease patients treated with Er Cr YSGG laser and PDT

AIM

To assess the effect of Er,Cr:YSGG (ECL) laser-assisted non-surgical treatment and Photodynamic therapy (PDT) as an adjunct to mechanical debridement (MD) on clinical and radiographic peri‑implant inflammatory parameters in patients with peri‑implant disease MATERIAL AND METHODS: A total of 95 patients with the peri‑implant disease were divided into 3 groups. Patients in group 1 were treated with MD only, patients in group 2 recieved MD+ECL and patients in group 3 were treated with MD+PDT. Perimplant parameters CBL: Crestal bone loss; PD: Probing depth; BI: Bleeding index; PI: Plaque index were measured from baseline to 3 month and 6 months follow up. The means and standard deviation (SD) of the aforementioned parameters were calculated using multiple comparison tests Post hoc Tukey test. Power analysis and sample size (PASS) was used for calculating sample size. The power was estimated at 85% along with a minimum of 30 participants in each group with a two-sided significance level of 0.05 was to be achieved RESULTS: At baseline mean scores of peri‑implant PI, BI and PD were comparable among patients in group 1 (control), 2 (ECL), and 3 (PDT). At 3 months follow up, mean scores of peri‑implant PI (P <0.05), BI (P <0.05) and PD (P <0.05) in group 1 (control) were significantly higher compared to group 2 (ECL) and 3 (PDT). At 6 months follow-up, PI and BI mean scores among groups 1, 2, and 3 were comparable (P>0.05). However, PD was significantly higher in control than groups 2 and 3 (P<0.05) CONCLUSION: MD with adjunct ECL and adjunct PDT are more efficient in reducing peri‑implant soft tissue inflammatory parameters for short-term use than MD alone.

Effect of photodynamic therapy on resin-dentin bonding interface using different illumination time

OBJECTIVES

The aim of the present study was to evaluate the effect of photodynamic therapy(PDT) on the resin-dentin bonding interface using different illumination time.

METHODS

Seventy completed, isolated molar teeth were collected for this study, sixty of them were used in microtensile bond strength tests. These teeth were initially divided randomly in two main groups(n=30) by the random number table method upon the type of using illumination or not respectively. Then these groups followed by dividing each category in five subgroups(n=6): group A, group B1,group B2, group B3, group B4, group a, group b1, group b2, group b3, group b4. After different treatment, the remaining teeth were made specimens which were observed the fracture modes and interfaces under a stereomicroscope and a scanning electron microscope(SEM). The dentin permeability of the specimens were evaluated by a laser scanning confocal microscope(LSCM). To detect significance difference between means of different groups analysis of variance(ANOVA) was performed followed by LSD-t tests.

RESULTS

There was a significant statistical difference in the microtensile bond strength of the different illumination time of PDT between four experimental groups and the control (P<0.05).

CONCLUSION

With the increase of the illumination time in PDT, the bonding strength between resin and dentin decreased gradually.

Influence of adjunctive non-surgical peri‑implant therapy on clinical and salivary cytokine profile in obese patients

AIM

The present study aimed to evaluate the impact of Photodynamic therapy (PDT) and Er,Cr:YSGG laser (ECL) adjunct to nonsurgical mechanical debridement (NSMD) in comparison to conventional NSMD in overweight individuals with peri‑implant disease on peri‑implant inflammatory parameters and cytokine levels of IL-6 and TNF-α in Peri-implant crevicular fluid (PICF) MATERIALS AND METHODS: Recruitment of volunteers was performed from the outpatient department according to predefined inclusion and exclusion criteria. Group 1 consisted of obese participants who underwent peri‑implant mechanical debridement (MD); group 2, obese participants who experienced MD adjunct to ECL, and in group 3, obese participants were treated with MD and adjunct PDT. Clinical periodontal parameters, plaque index (PI), bleeding index (BI) and probing depth (PD) along with crestal bone loss (CBL) were assessed at baseline, 3 months, and 6 months. PICF was collected to evaluate the levels of IL-6 and TNF-α. Kruskal-Wallis and Bonferroni post hoc test were employed for the comparison of peri‑implant inflammatory parameters and PICF cytokine profiles among the study groups.

RESULTS

Clinical peri‑implant parameters (PI, BI and PD) at baseline among subjects in group 1, group 2 and group 3 were comparable (p > 0.05). At 3 months follow up, mean scores of peri‑implant PI, BI, and PD (P <0.05) in group 1 (control) were significantly higher compared to group 2 (ECL) and 3 (PDT) (p < 0.05). At 6 months follow-up, PI and BI mean scores among groups 1, 2, and 3 were comparable (p>0.05). At 6 months participants in groups 2 and 3 noted significant difference (p<0.05) compared to baseline with no difference noted in the control group (p>0.05).

CONCLUSION

Photodynamic therapy and Er, Cr: YSGG adjunct to NSMD demonstrated significant improvement in peri‑implant inflammatory parameters in obese individuals. Multicentric clinical trials are suggested to extrapolate the findings of the present study.

Impact of photodynamic therapy as an adjunct to non-surgical periodontal treatment on clinical and biochemical parameters among patients having mild rheumatoid arthritis with periodontitis

PURPOSE

To evaluate the efficacy of photodynamic therapy (PDT) as an adjunct to non-surgical periodontal therapy on the clinical periodontal and biochemical parameters among patients with rheumatoid arthritis (RA) having periodontitis.

METHODS

A total of 50 RA patients with periodontitis were included. The subjects were equally divided into two groups: Group A - scaling and root planning (SRP) + PDT; Group B - SRP only, respectively. Plaque score (PS), bleeding on probing (BOP), and pocket depth (PD) were estimated. The biochemical parameters included the assessment of interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-α) and rheumatoid factors (RFs).

RESULTS

Plaque scores and BOP significantly reduced in both the groups at both 6 and 12 weeks with significant difference between both the groups at 6 weeks follow up (p<0.05). On inter-group comparison, there was a statistically significant reduction seen for BOP in Group A at 12 weeks (p<0.001). PD significantly reduced in both the groups at both time points; however, significant reduction was noted for Group A compared to Group B (p<0.01). IL-6 and TNF-α significantly reduced in both the groups at 6 and 12 weeks follow up. However, the proinflammatory cytokine levels significantly reduced in group A as compared to group B at both 6 and 12 weeks (p<0.05). GCF levels of RF did not show any change in either of the groups at either time point or between the groups (p>0.05).

CONCLUSION

PDT significantly reduced the proinflammatory burden in terms of periodontal attachment level and bleeding on probing within the periodontal inflammatory pockets in patients having RA.

Hydrogen peroxide potentiates antimicrobial photodynamic therapy in eliminating Candida albicans and Streptococcus mutans dual-species biofilm from denture base

BACKGROUND

Candida albicans (C.albicans) is the primary pathogen of denture biofilm. Moreover, it could establish a cross-kingdom relationship with bacteria to enhance its virulence and resistance to antifungal drugs. This study aimed to investigate the efficacy of antimicrobial photodynamic therapy (aPDT) in combination with hydrogen peroxide (H₂O₂) against C.albicans and Streptococcus mutans (S.mutans) dual-species biofilm formed on polymethyl methacrylate (PMMA) disk, and explore its involved mechanisms.

METHODS

C.albicans and S.mutans were grown on PMMA disk for 48 h to form biofilm and received different treatments. The treatments included:1) phosphate-buffered saline (PBS) group,2) 100 mM H₂O₂ group,3) aPDT group,4) aPDT+ H₂O₂ and 5) H₂O₂+aPDT group. Colony forming units (CFU), 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and scanning electron microscope (SEM) were used to evaluate the antimicrobial effects. Extracellular polysaccharide substance (EPS) production and observation, cell permeability of biofilm, and uptake of toluidine blue O (TBO) by biofilm were assessed to investigate the involved mechanism.

RESULTS

There was no significant difference between PBS group and H₂O₂ group in viable microorganisms and metabolic activity of biofilm. The treatment protocols containing aPDT group reduced microorganism numbers and metabolic activity when compared to PBS group or H₂O₂ group (P<0.05). H₂O₂+aPDT treatment showed the highest antimicrobial efficacy in comparison with other treatments (P<0.05). Pretreatment with H₂O₂ could decrease EPS production and enhance cell permeability, leading to increased TBO uptake in biofilm.

CONCLUSION

Pretreatment with H₂O₂ improved aPDT efficiency in eliminating dual-species biofilm from PMMA disk by reducing EPS amount, enhancing cell permeability, and increasing TBO uptake.

How can biophotonics help dentistry to avoid or minimize cross infection by SARS-CoV-2?

Biophotonics is defined as the combination of biology and photonics (the physical science of the light). It is a general term for all techniques that deal with the interaction between biological tissues/cells and photons (light). Biophotonics offers a great variety of techniques that can facilitate the early detection of diseases and promote innovative theragnostic approaches. As the COVID-19 infection can be transmitted due to the face-to-face communication, droplets and aerosol inhalation and the exposure to saliva, blood, and other body fluids, as well as the handling of sharp instruments, dental practices are at increased risk of infection. In this paper, a literature review was performed to explore the application of Biophotonics approaches in Dentistry focusing on the COVID-19 pandemic and how they can contribute to avoid or minimize the risks of infection in a dental setting. For this, search-related papers were retrieved from PubMED, Scielo, Google Schoolar, and American Dental Association and Centers for Disease Control and Prevention databases. The body of evidence currently available showed that Biophotonics approaches can reduce microorganism load, decontaminate surfaces, air, tissues, and minimize the generation of aerosol and virus spreading by minimally invasive, time-saving, and alternative techniques in general. However, each clinical situation must be individually evaluated regarding the benefits and drawbacks of these approaches, but always pursuing less-invasive and less aerosol-generating procedures, especially during the COVID-19 pandemic.

Comparative Evaluation of the Effects of Antimicrobial Photodynamic Therapy With an LED and a Laser on the Proliferation of Human Gingival Fibroblasts on the Root Surface: An In Vitro Study

Introduction: This study aimed to compare the effects of root biomodification by citric acid and antimicrobial photodynamic therapy (aPDT) with LED and laser on the proliferation of human gingival fibroblasts (HGFs). Methods: This in vitro experimental study evaluated 60 single-rooted teeth extracted due to periodontal disease. The teeth underwent scaling and root planing (SRP), and then 5 × 5 mm blocks were prepared from the cervical area of the teeth 1 mm apical to the cementoenamel junction. The blocks were divided into 4 groups (n=15 blocks): SRP alone (control), SRP + citric acid, SRP + toluidine blue (TBO) + LED light, and SRP + TBO + laser. HGFs were seeded on the surface of the samples, and the methyl thiazolyl tetrazolium (MTT) assay was performed after 24, 48 and 72 hours. Group comparisons were performed using repeated measures ANOVA, while pairwise comparisons of the time points were performed by an LSD test. Results: Cell proliferation was higher in all experimental groups at 48 and 72 hours, compared with 24 hours (P < 0.05). Cell proliferation was significantly different in the citric acid group at 24 hours (P = 0.016) and 48 hours (P = 0.015), compared with other groups. However, cell proliferation was not significantly different in the aPDT group with LED Photosan and a diode laser at 24 and 48 hours (P > 0.05). Conclusion: aPDT and citric acid can enhance the proliferation of HGFs on dentin blocks. Further studies can pave the way for their future use in the clinical setting.

Interdental Plaque Microbial Community Changes under In Vitro Violet LED Irradiation

Oral microbiome dysbiosis has important links to human health and disease. Although photodynamic therapy influences microbiome diversity, the specific effect of violet light irradiation remains largely unknown. In this study, we analyzed the effect of violet light-emitting diode (LED) irradiation on interdental plaque microbiota. Interdental plaque was collected from 12 human subjects, exposed to violet LED irradiation, and cultured in a specialized growth medium. Next-generation sequencing of the 16S ribosomal RNA genes revealed that α-diversity decreased, whereas β-diversity exhibited a continuous change with violet LED irradiation doses. In addition, we identified several operational taxonomic units that exhibited significant shifts during violet LED irradiation. Specifically, violet LED irradiation led to a significant reduction in the relative abundance of Fusobacterium species, but a significant increase in several species of oral bacteria, such as Veillonella and Campylobacter. Our study provides an overview of oral plaque microbiota changes under violet LED irradiation, and highlights the potential of this method for adjusting the balance of the oral microbiome without inducing antibiotic resistance.

Influence of synthetic and natural photosensitizers activated by photodynamic therapy on extrusion bond strength of fiber post to radicular dentin

OBJECTIVE

To assess the effect of different photosensitizers activated by low-level laser therapy on EBS of glass fiber post to radicular dentin.

METHODS

This study was conducted at King Saud University from January 2021 to March 202. Fifty maxillary central incisors were sanitized and decoronated. NiTi was used for mechanical instrumentation of the canal. All canals were shaped, cleaned and obturated with gutta-percha. Post space was made using peso reamers. Four Division of groups were made according to photosensitizers used (n=10). Group-1: MBP at 100mg/l, Group-2: Phycocyanin at 100mg/l, Group-3: CP at 500mg/l, and Group-4 toluidine blue photosensitizer (TB). Lasers were used for activation of photosensitizers. In Group-5 samples were irrigated using sodium hypochlorite NaOCl +17% EDTA. Posts were cemented and teeth sectioned into apical, coronal and middle. For EBS all samples were subjected to a universal testing machine. Fracture patterns were analyzed using stereomicroscope. To compare EBS at different segments One-way analysis of variance (ANOVA) and Tukey multiple comparison tests (p=0.05) was performed.

RESULTS

The maximum value of EBS was shown in Group-2 radicular canal treated with CP with 17% EDTA at all three levels cervical (8.61±1.32 MPa), middle (6.81±0.73 MPa), and apical (5.51±0.25 MPa). Similarly, the minimum value of EBS was displayed in Group-5 canal irrigated with 2.25% NaOCl +17% EDTA (control) coronal (6.10±1.77 MPa), middle (5.11±0.75MPa), and apical (3.60±0.94 MPa). Intragroup assessment disclosed a decrease in EBS from cervical one-third to apical one-third in all groups.

CONCLUSION

P, CP, and TB along with EDTA have the potential to be used as canal disinfectant and favors the bonding of GFP to radicular dentin using self-etch adhesive resin.

Photodynamic therapy and gaseous ozone versus conventional post space treatment methods on the push-out bond strength of fiber posts luting with different resin cements

BACKGROUND

The aim of this study was to compare the push-out bond strength of fiber posts by using two different resin cement after the treatments of post space with photodynamic therapy, gaseous ozone and conventional disinfection solution.

METHODS

The root canal treatments of one hundred maxillary incisors were performed. The roots were randomly distributed into 5 groups (n = 20). NaOCl of 2.5% + EDTA of 17% in group 1, CHX of 2% in group 2, toluidine blue + diode laser as the photodynamic therapy (PDT) in group 3 and ozone in group 4 were applied to the post spaces. Group 5 was washed with distilled water as control group. Each group was divided into two subgroups according to the adhesive types and the posts were bonded by using RelyX and LinkForce. The bond strength was calculated using the push-out test method. Resin tag formations were photographed with SEM. The push-out bond strength was analyzed by ANOVA and Tukey tests (p = .05).

RESULTS

The PDT group, which showed the highest PBS among the groups bonded with LinkForce at all levels, was significantly higher than Ozone and DW groups (p<.05). NaOCl and ozone treatments provided the highest PBS among the groups bonded with RelyX for all levels and this difference was significant according to the DW group (p < .05).

CONCLUSION

Post space treatments improved the bond strength of the fiber post ​​in both types of resin cement.

Effectiveness of photodynamic therapy on bonding strength and failure modes of fiber-posts in c-shaped treated root canals

AIM

The present study aimed to assess the push-out bond strength (PBS) and failure modes of fiber-posts after photodynamic therapy (PDT) and Erbium yttrium scandium gallium garnet (Er,Cr:YSGG) in c-shaped canals.

METHODS

Sixty molars with c-shaped root configuration were studied. The endodontic prepared teeth specimen were equally randomized into four groups: i) photodynamic therapy (PDT); ii) Er,Cr:YSGG; iii) chlorhexidine and; iv) control group. Post root filling, 10 mm space was prepared for insertion of post in the root canals. The push-out bond strength was evaluated using Universal testing machine. Modes of failure were evaluated as adhesive, cohesive and admixed. Mean values were computed between groups using Kruskal-Wallis test followed by Bonferroni post hoc test. Comparison between two thirds of root sections were analyzed using Friedman test. P-value was set at 0.05 or less.

RESULTS

Specimens treated with PDT reported the highest mean PBS (8.56 ± 2.12 MPa), while the lowest PBS was observed in NaOCl group (6.92 ± 2.21 MPa). Thirteen failures were observed at the adhesive post interface, whereas 22 failures were found at the interface forming between the dentin surface and adhesive. Similarly, 9 failures were categorized as mixed. For PDT group, a sum of 3 failures and 4 failures were noted at the apical and cervical points.

CONCLUSION

The specimens treated with PDT showed the highest push out bond strength with least number of failures.in c-shaped root canals.

Impact of riboflavin and curcumin mediated photodynamic therapy and Er,Cr:YSGG on microleakage of class V resin glass ionomer restorations in permanent molar teeth

PURPOSE

The present study aimed to evaluate the impact of PDT using curcumin and riboflavin as photosensitizers and Er,Cr:YSGG on microleakage in class V RMGIC restorations in permanent teeth.

MATERIALS AND METHODS

Eighty permanent molars were investigated and randomly divided into 4 groups: control group: resin-modified glass ionomer restoration with no treatment, R-PDT: PDT with riboflavin, Cu-PDT: PDT with curcumin (Cu) and, Er,Cr:YSGG: laser application. All the teeth in each group were restored with the help of RMGIC. The samples were dipped for 24 h in 0.5 % Fuchsine solution, and subsequently fixed in acrylic resin-based molds. Microleakage scores were estimated considering both cervical and occlusal boundaries. Intergroup comparisons were made at each margin, and intragroup comparisons made at the cervical and occlusal margins. The Shapiro Wilk test was used to check the normality of the values. Whereas, the analysis of data was conducted using SPSS version 25 via the Kruskal-Wallis and Wilcoxon tests. P < 0.05 was contemplated to be statistically important.

RESULTS

A high frequency (95%) of the enamel walls were not penetrated when subjected to treatment with R-PDT, followed by Cu-PDT and Er,Cr:YSGG. The highest amount of microleakage was observed (55%) Cu-PDT at the site of the cavity near the cementum. The least amount of microleakage was observed in the control group. A statistically significant difference in microleakage was noted at the cervical wall (p=0.015), while no significant difference was seen at the occlusal wall (p=0.789) between the groups. A significant difference was noted at the cervical wall between the control and R-PDT group (p=0.021) and Cu-PDT group (p=0.005), respectively. A significant difference in microleakage was observed when occlusal was compared with cervical walls within each group (p<0.05).

CONCLUSION

Photosensitizers using riboflavin and curcumin may reduce the microleakage within the enamel surface restored with RMGIC in class V lesions that may not interfere with bonding. However, extreme caution should be taken while considering riboflavin and curcumin for class V RMGIC restorations extending to cementum surface.

Effect of Photodynamic therapy and Er,Cr: YSGG laser on bond strength of bleached enamel to composite resin

OBJECTIVE

The purpose of the present study was bleached enamel reversal using conventional ascorbic acid (AA) and contemporary methods including Photodynamic therapy (PDT), Er, Cr: YSGG (ECL) on bond integrity to composite resin.

MATERIAL AND METHOD

Forty sound permanent mandibular premolars were collected from a dental clinical setting and disinfected. All forty samples were mounted vertically in a rubber mold exposing only the clinical crown. All samples were bleached using Opalescence Boost Professional Teeth Whitening. After the bleaching procedure, each sample was randomly allocated into four groups according to surface treatment. Samples in group 1 were treated with methylene blue photosensitizer (MBP). Samples in group 2 were exposed to 10% sodium ascorbate. Samples in group 3 were treated with Er, Cr: YSGG laser (ECL). Samples in group 4 were not treated (control). All Samples were treated with 37% phosphoric acid and a bonding agent was applied. A bulk-fill composite was cured to all specimens and all samples were treated in a thermocycler. Specimens were placed in a universal testing machine for shear bond strength (SBS) testing. Descriptive statistics were associated by analysis of variance (ANOVA) and Tukey's post hoc test maintaining level of significance (p<0.05) RESULTS: The lowest SBS scores were achieved in the bleached enamel (BE) group (15.25±1.745 MPa). Whereas, the highest bond integrity was attained by AA group (32.23±1.854 MPa). Samples treated with ECL (31.87±1.659 MPa) and AA (32.23±1.854) were comparable (p>0.05). Samples treated with PDT exhibited significantly different SBS (22.41±1.258) compared to other experimental groups CONCLUSION: ECL showed a reversal effect of BE compared to AA and has the potential to be used in clinical settings. BE reversal using MBP needs further investigation.

Effect of ultrasonic scaling with adjunctive photodynamic therapy on the treatment of gingival inflammation among diabetic patients undergoing fixed orthodontic treatment

BACKGROUND

The aim of the present clinical trial was to evaluate the effect of methylene blue-mediated antimicrobial photodynamic therapy (aPDT) on the gingival and immunological parameters in diabetic adolescent patients undergoing fixed orthodontic treatment.

METHODS

The selected 40 participants were randomized equally into two groups; Group I (ultrasonic scaling + oral hygiene instructions) and Group II (ultrasonic scaling/oral hygiene instructions + aPDT). Serum HbA1c levels was assessed for all the participants at chairside. Plaque index (Pi), and bleeding on probing (BOP) were analyzed. Moreover, the assessment of crevicular fluid matrix metalloproteinase 8 (MMP-8) and macrophage inflammatory protein 1 alpha (MIP-1α) was performed using enzyme-linked immunosorbent assay technique. All measurements were recorded at baseline, 6 weeks, and 12 weeks follow-up periods, respectively. Intergroup comparisons for p-value were computed using Mann-Whitney test and Wilcoxon singed ranks test to compute p-value for intra-group comparisons. Stepwise logistic regression analysis was used to identify explanatory variables for reduction in plaque scores and bleeding on probing, after controlling for the effects of other covariates. Odds ratios and 95% confidence intervals were used to assess the direction and strength for associations. Significance level was set at 5% for all analyses.

RESULTS

All 40 individuals completed the clinical trial. There was a statistically significant reduction in Pi and BOP in both Group I and Group II from baseline to 12 weeks of follow up (P<0.05). However, there was slight reduction in the plaque scores in Group-II as compared to Group-I at 12 weeks visit (P<0.05). There was also a statistically significant difference for BOP when Group-I was compared with Group-II on 12 weeks follow up assessment (P<0.05). HbA1c assessment indicated no statistically significant difference either within or between groups at any time point (P>0.05). Both MMP-8 and MIP-1α reported a significant decrease for both Groups I and II at 6 weeks and 12 weeks follow-up periods in comparison to baseline (P<0.05). Inter-group comparison indicated a statistically significant difference noted at both 6 weeks follow up that was maintained at 12 weeks follow up (P<0.05). The logistic regression analysis revealed that even after controlling the mean BMI as a predictor, the change of biomarker levels along with the improvement in plaque scores and bleeding on probing was not significant (p> 0.05).

CONCLUSION

aPDT significantly improved bleeding on probing and proinflammatory biomarkers among diabetic adolescent patients undergoing fixed orthodontic therapy.

Effectiveness of photodynamic therapy as an adjunct to topical antiviral therapy in the treatment of herpes labialis: A randomized controlled clinical trial

BACKGROUND

The present clinical trial assessed the effectiveness of photodynamic therapy in association with topical acyclovir in the treatment of herpes labialis in adolescent patients.

MATERIALS AND METHODS

45 individuals with herpes labialis were divided into three groups on the basis of provision of treatment. (a) Group I: Topical acyclovir therapy (AVT) (n = 15, mean age: 17.5 years) (b) Group 2: photodynamic therapy (PDT) (n = 15, mean age:16.8 years) and (c) Group III: AVT + adjunctive PDT (n = 15, mean age: 17.0 years) respectively. HSV-1 quantification and pain scales [visual analogue scale (VAS) and McGill Pain Questionnaire (MPQ)] were calculated. Pro-inflammatory biomarkers including interleukin (IL-6) and tumor necrosis factor-alpha (TNF-α) were quantified using enzyme linked immunosorbent assay (ELISA). Shapiro-Wilk test was used to assess the normality. The Friedman test was employed to compute the comparison for changes recorded in pain scores, proinflammatory cytokines and HSV-1 quantification, whereas Mann-Whitney test was used to analyze the mean values and establish inter-group comparisons. All assessments were performed at baseline, immediate post op, 2-weeks, 4-weeks, 3-months, and 6-months.

RESULTS

A total of 44 individuals completed the clinical trial. According to the data obtained from the clinical assessment, all the study groups reported a decrease in the parameters being observed. However, Group III (anti-viral (acyclovir) therapy + adjunctive PDT) showed a statistically significant decrease, in comparison to Group II (PDT) and Group I [AVT] respectively. The quantified HSV-1 among all groups showed significant reduction among all groups at each successive follow-up. However, Group-III (AVT + PDT) showed statistically significant reduction as compared to Groups I and II, respectively (p < 0.05).

CONCLUSION

Topical anti-viral therapy with adjunctive PDT significantly helped in reducing the pain and pro-inflammatory biomarkers in adolescent herpes labialis patients.

Influence of Photodynamic therapy and different gingival retraction agents on bond integrity of composite to dentin

AIM

The present study was undertaken to evaluate the influence of gingival retraction agents (Expasyl and Viscostat) and different conditioning methods (Total-etch, Self-etch, and PDT) on bond integrity of composite to dentin.

MATERIAL AND METHODS

One hundred and eighty, third molars were collected cleaned and disinfected in thymol solution. The specimens were rooted vertically up to cementoenamel junction within polyvinyl cylinders (PVC). Based on gingival retraction materials samples were divided into three groups (n = 60). Group A: dentin applied with Expasyl; Group B: Viscostat was applied on dentin and Group C: Control. Dentin surface was treated with different surface conditioners. Etch and rinse, PDT MBP, and Two-step self-etch. A bonding agent was applied and composite buildup was done. Samples were placed in the universal testing machine for SBS. Bond failure was assessed using a stereomicroscope. Analysis of variance (ANOVA) and Tukey's post hoc test compared the means and standard deviations (SD) after SBS testing (p = 0.05).

RESULTS

The highest score of bond strength was exhibited by group C1 (21.14 ± 1.05 MPa-Etch & rinse + Tetric-N- Bond) whereas group C2 (12.15 ± 0.28 -PDT MBPS + Tetric-N-Bond, No treatment group) demonstrated the lowest SBS. Based on the application of haemostatic agent, bond values among subgroups A1 (18.75 ± 1.05 MPa - Expasyl + Etch & rinse + Tetric-N-bond) and B1 (17.84 ± 0.11 MPa -Viscostat + Etch & rinse + Tetric-N-Bond) was comparable (p>0.05). Based on the conditioning methods, bond scores among groups C1 (21.14 ± 1.05 MPa -Etch & rinse + Tetric-N- Bond) and C3 (19.05 ± 1.28 MPa -Clearfill SE) were comparable (p >0.05).

CONCLUSION

Viscostat and Expasyl result in compromised bond integrity of composite restoration to dentin in etch and rinse and self-etch group compared to no treatment group. However, the pre-application of Viscostat and Expasyl on dentin conditioned with PDT improved bond integrity of composite resin.

The effect of antimicrobial photodynamic therapy on shear bond strength of orthodontic bracket: An in vitro study

OBJECTIVES

The aim of this study was to evaluate the effect of antimicrobial photodynamic therapy (aPDT) with methylene blue (MB) and indocyanine green (ICG) on bond strength of orthodontic brackets to enamel.

MATERIALS AND METHODS

A total of 45 non-carious and sound human premolar teeth were used in this study. All teeth were examined under a stereomicroscope at ×10 magnification. The samples were divided to 3 groups including no treatment (control group), aPDT with MB and 660 nm diode laser and aPDT with ICG and 808 nm diode laser. After aPDT procedure, orthodontic brackets were bonded to enamel surfaces. Then, the samples were thermocycled for 5000 cycles between 5° and 55° C in water bath. The brackets were then debonded using a universal testing machine. The adhesive remnant index (ARI) score and SEM microscope evaluation were assessed. One-way analysis of variance (ANOVA) with Post-hoc test were used to compare the SBS values among groups.

RESULTS

The highest SBS mean value was presented in group 1 (control) (31.98 ± 6.36). Whereas, the lowest SBS mean value was observed in group 3 (aPDT with ICG) (24.11 ± 5.78). There were significant differences in SBS values between control and aPDT groups (P < 0.05). Some superficial porosity and irregularity was presented following aPDT on surface of enamel when examined by scanning electron microscope. The mode of failure was mostly score 0 and score 1 in all groups.

CONCLUSION

MB and ICG mediated antimicrobial photodynamic therapy both reduced the bond strength of orthodontic brackets compared to control group.

Impact of riboflavin mediated photodynamic disinfection around fixed orthodontic system infected with oral bacteria

PURPOSE

The aim of this laboratory study was to investigate the amount of bacterial destruction through riboflavin mediated photodynamic therapy (PDT) around fixed orthodontic devices by using the two strains of bacteria Streptococcus mutans and Streptococcus sanguinis.

MATERIALS AND METHODS

A total of 80 metallic brackets were divided into four groups consisting of 20 brackets each. Group-I: riboflavin + LED irradiation; Group-II: riboflavin alone; Group-III: immersion in 0.2 % chlorhexidine gluconate solution and Group-IV: not submitted to any treatment. All metallic brackets were immersed in the standard bacterial solutions and incubated at 48 h. All samples were subjected to MTT assay for microbial cell viability testing after treatment. After 24 h of incubation, biofilms adhered on the mesh of metallic brackets after treatment were assessed by confocal laser microscopy. The total CFU/mL was estimated, and the results were log-transformed (log₁₀) and analyzed using one-way analysis of variance and Tukey-Kramer test. P-value was set to <0.05 that indicated statistical significance.

RESULTS

The samples from group-IV showed the highest amount of relative biofilm viability compared to any other group while group-I (PDT) showed the least viability of the two bacterial strains studied (p < 0.05). Group-I showed no significant difference when compared with group-III (chlorhexidine) (p > 0.05). The biofilms on the samples from group-II and group-IV were largely viable indicating thick green staining across the mesh of the brackets. Among the group-III samples, there were predominantly dead cells as compared to the live cell staining. A considerable amount of red staining was observed with noticeable less green staining in group-I samples.

CONCLUSION

This laboratory investigation revealed that riboflavin mediated PDT significantly reduced the amounts of S. mutans and S. sanguinis around the orthodontic brackets.

Evaluation of gingival displacement methods in terms of periodontal health at crown restorations produced by digital scan: 1-year clinical follow-up

The purpose of this clinical study was to compare the effects of the gingival displacement techniques of retraction cord, cordless paste system, and Er,Cr:YSGG laser troughing on the periodontal tissues around the crown restoration produced using a digital scan. This was analyzed by recording the probing depth (PD), plaque index, gingival index (GI), mobility, sensitivity, and bleeding on probing (BOP) index. This study included 60 mandibular 1^st molars from 52 participants (20 males and 32 females) requiring crown restoration. The margin lines of the crown preparations were placed 1 mm subgingivally. Based on the gingival displacement technique used, the patients were divided into three groups: retraction cord, cordless paste system, and Er,Cr:YSGG laser troughing. A digital scan of the prepared tooth was performed. Follow-up appointments were scheduled at five different times: 1^st day, 1^st month, 3^rd month, 6^th month, and 1^st year. Six periodontal indices were used to assess the periodontal health. The chi-square test was used to compare categorical variables depending on the groups. There was a significant difference in the PD, GI, and BOP index scores among the three techniques during the 1-year clinical monitoring (p < 0.001). The PD in the three zones of the buccal surface showed a significant increase with time in the retraction cord and cordless paste system groups (p < 0.001). The highest GI scores were observed in the retraction cord group on the 1^st day. The Er,Cr:YSGG laser troughing procedure produced lower PD, GI, and BOP index scores as compared to the retraction cord and cordless paste system procedures in the 1-year period.

Efficacy of photodynamic therapy, photobiomodulation and antimicrobial agent on the shear bond strength of composite restorations to hypomineralized teeth

PURPOSE

The aim of this study was to investigate the adhesive bond strength and fracture analysis of resin based restorations to carious dentin of hypomineralized molars (HMs) after disinfecting with photodynamic therapy (PDT), Nd:YAG and chlorhexidine (CHX).

MATERIALS AND METHODS

Sixty carious HM molars were investigated. After removal of all carious infected tissue, the cavities were condition with methylene blue initiated PDT, a 1064 nm wavelength Nd:YAG laser or 2.0% CHX gel. Non-carious dentin from HM was used as a control without performing any disinfection or conditioning technique. All samples were bonded using a one-step one-coat adhesive bond over the dentin surface, packed with composite and light cured. All specimens were subjected to thermocycling at 5°C and 60°C with a dwell time of 30 s for 10,000 cycles. Bonded specimens were placed on a universal testing machine with a flat loading head. The debonded surface were viewed under light optical microscope to estimate the type of failure including adhesive, cohesive, and admixed.

RESULTS

The highest mean SBS was seen in the non-carious HM (control group). The mean score for control group was 17.64 ± 2.96 MPa. The lowest bond strength value was displayed for Group-PDT (11.37 ± 3.66 MPa) and Group-Nd:YAG (12.69 ± 2.45 MPa). Affected dentin disinfected with the Group-CHX (15.71 ± 3.04 MPa) bonded with composite showed statistically significantly higher SBS values compared to the laser groups (p < 0.05). No statistically significant difference was noted with specimens disinfected with PDT and Nd:YAG laser showed comparable SBS scores (p > 0.05). Fracture analysis showed equal incidence of adhesive and cohesive failures in control group and Group-CHX. Moreover, a significant number of failures in group-PDT were related to adhesive. Whereas in group 4, admixed type failures were common.

CONCLUSION

Caries infected hypomineralized teeth demonstrated lower bond strength values compared to non-carious hypomineralized teeth. Adhesive bond strength of hypomineralized teeth was highest with chlorhexidine compared to other laser treatment strategies.

Effectiveness of Riboflavin and Rose Bengal Photosensitizer Modified Adhesive Resin for Orthodontic Bonding

This study aimed to evaluate the effect of riboflavin (RF) and Rose Bengal (RB) photosensitizer modified adhesive resin on the degree of conversion (DC), and antimicrobial capacity after bonded to tooth surface. Different concentrations of RB and RF were prepared by homogenization method. An ultraviolet light source A (UVA) (375 nm wavelength, 3 mW/cm² power) was used for 30 min irradiation. FTIR was performed for control and test adhesives to analyze the DC. Antibacterial testing was performed using the MTT assay. Metal brackets were bonded using the modified adhesives and subjected for SEM examination. The surfaces of teeth and metal brackets were examined at ×10 magnification for assessing adhesive remnant index (ARI) after PDT, 24 h and thermocycling. For DC, control group, 0.1% RB and RF after PDT showed the highest value. SEM imaging indicated lowest growth of Streptococcus mutans over 0.5% of RB-PDT and RF-PDT as compared to the control group. The MTT assay outcomes reported that the activity of S. mutans substantially decreased with the addition of a high amount of either RB or RF (p < 0.01). Mean ARI scores showed a significant difference between all groups. This study concluded that 0.1% of either RB or RF after PDT can be used for bonding orthodontic brackets to the tooth surface with substantial antibacterial properties.

Comparison of adhesive bond strength among fiber reinforced post and core with different cementation techniques: In vitro study

AIM

To investigate push-out bond strength (PBS) of fiber post to radicular dentin after using different cementation techniques.

MATERIAL AND METHODS

Sixty single-rooted premolars were disinfected and cleaned by mechanical instrumentation. S1, S2, and SX were used for canal shaping and finishing of the canal was carried out using F1 and F2. This was followed by constant irrigation and smear layer removal using 17%EDTA. The canal was dried filled with gutta-percha and canal space was prepared using a peso reamer. Based on cementation techniques, samples were randomly allocated into six groups. Group 1: One-step Monoblock MC; Group 2: One-step, Monoblock MC-NA (no adhesive) GFP; Group 3: One-step, RX-MC-Monoblock; Group 4: Two-step, RX-MC; Group 5: Two-step, RX-FZ; and Group 6: Two-step RX-FZ-custom post. All specimens were mounted in polyvinyl pipes using acrylic resin up to cement enamel junction. All specimens were mounted in a universal testing machine subjected to push-out forces at a speed of 0.5 mm/min. Five samples from each group were sputter-coated with 6 nm gold thickness for 300 s at 250 mA. The coated specimens were assessed under the scanning electron microscope (SEM). Analysis of variance (ANOVA) and Tukey Kramer multiple comparisons tests were performed to compare means among groups maintaining the level of significance at (p < 0.001).

RESULTS

The highest PBS was displayed in RX-MC-Monoblock (199.020 ± 21.432 MPa). Whereas, lowest PBS was found in Monoblock MC-NA (no adhesive)-GFP (76.440 ± 9.468 MPa). Among one-step groups, RX-MC Monoblock exhibited the highest PBS (199.020 ± 21.432 MPa) comparable to one-step Monoblock MC (134.28 ± 19.37 MPa) (p > 0.05). Similarly, among two-steps groups, two-step RX-MC demonstrated significantly higher PBS values than two-step RX-FZ (143.340 ± 23.68 MPa) and RX-FZ-custom post (86.90 ± 7.41 MPa) (p < 0.05).

CONCLUSION

One-step RX-MC-Monoblock technique using self-adhesive cement and core foundation composite resin material multicore flow when cured simultaneously exhibited the highest bond integrity of post retention compared to other cementation technique.

Impact of graphene oxide and silver diamine fluoride in comparison to photodynamic therapy on bond integrity and microleakage scores of resin modified glass ionomer cement to demineralized dentin

AIM

To evaluate the impact of graphene oxide (GO) and silver diammine fluoride (SDF) in comparison to photodynamic therapy (PDT) on adhesive bond integrity and microleakage scores of resin-modified glass ionomer cement (RMGIC) to demineralized dentin.

METHODS

80 non-carious and atraumatic third molars were mounted inside the segments of polyvinyl pipes. Exposure, homogenization, and polishing of dentinal tubules was performed. 20 specimens were left unconditioned and classified a group 4. Exposure of acetic acid was done to 60 specimens and randomly allocated into 3 groups. Group 1 specimens were treated with 0.25 % GO; group 2 specimens were treated with 3.8 % SDF; and group 3 specimens were exposed to PDT. The bonding of all samples to RMGIC was performed by light curing and universal testing machine was utilized for testing shear bond strength (SBS). For failure modes, an optical microscope at 40x magnification was used to observe the debonded interfaces. For microleakage, all the specimens were submerged in 2% methylene blue for 1 day and observed under a digital microscope. The post hoc Tukey and analysis of variance (ANOVA) were used to examine SBS. A p-value of ≤0.05 was considered statistically significant.

RESULTS

Group 2 showed the highest bond strength (3.8 % SDF + RMGIC + DD - 15.27 ± 2.19 MPa). Groups 1 (0.25 % GO + RMGIC + DD - 14.11 ± 3.82) and 2 showed comparable results of SBS, which was significantly higher when compared with other research groups (p < 0.05). According to the post hoc Tukey test, the SBS scores of treatment groups exhibited statistically significant values as compared to the control group (p < 0.05). Group 2 samples showed the least microleakage mean score (0.8 ± 0.42), followed by group 1 specimens (1.02 ± 0.88). The comparable microleakage mean scores were demonstrated by the samples in group 1 and 2 (p < 0.01). According to one-way ANOVA, a significant difference was observed in microleakage scores among experimental groups (p < 0.01).

CONCLUSION

Improved bond strength and marginal microleakage scores were demonstrated by the demineralized dentin treated with 0.25 % graphene oxide and 3.8 % silver diamine fluoride when bonded to resin-modified glass ionomer cement. The application of methylene blue photosensitizer for photodynamic therapy undermined the adhesive bond strength applied on demineralized dentin.

Antimicrobial capacity and physico-chemical characteristics of adhesive resin containing riboflavin after photodynamic therapy

PURPOSE

To assess the micro-tensile bond strength (μ-TBS), degree of conversion, and antimicrobial capacity of modified dentin adhesive using riboflavin photoinitiators.

MATERIALS AND METHODS

Three groups of adhesives (control; 0.1 % riboflavin-PDT and 0.5 % riboflavin PDT) were prepared and tested on 70 sound molar teeth. Fourier-transformed infrared spectroscopy (FTIR) was performed for riboflavin and riboflavin-modified adhesives to calculate the degree of conversion. Contact angle measurement was performed by dropping a 5 μL droplet of the adhesives onto polished dentin disk. For μ-TBS testing, the dentin beams were fixed on a micro-tensile tester and were loaded in tension at a cross-head speed of 1 mm per min until fracture. The viability of Streptococcus mutans biofilm was tested using MTT assay.

RESULTS

The spectrum at 1728 cm-1 indicates CO stretching frequency of riboflavin. The groups control and 0.1 % riboflavin PDT showed the highest degree of conversion followed by lowest degree of conversion of 0.5 % riboflavin adhesive after PDT. The control adhesive exhibited the highest contact angle over the dentin surface compared to the riboflavin-modified adhesive groups (p < 0.05). The lowest contact angle was observed for 0.1 % riboflavin that showed increased permeability of the adhesive onto the dentin surface (p < 0.05). The variables of immediate bonding (F = 12.328, p = 0.000) and ageing in artificial saliva (F = 41.559, p = 0.000) significantly affected the bond strength. For aged μ-TBS testing, the scores for 0.1 % riboflavin PDT was significantly higher as compared to the 0.5 % riboflavin PDT samples. The MTT resulted in a lower S. mutans viability for 0.5 % riboflavin PDT compared to 0.1 % riboflavin PDT and control adhesive (p < 0.05), irrespective of any time point, that is, after 24 h and 30 days ageing.

CONCLUSIONS

The addition of riboflavin as photosensitizer in dentin adhesive demonstrated higher bond strength, excellent antimicrobial capability, and degree of conversion following PDT. The addition of riboflavin in dentin adhesive for PDT could be used as a potential restorative material in adhesive dentistry.

Antimicrobial capacity of photodynamic therapy on oral health-related quality of life and halitosis among elderly patients wearing removal dentures

PURPOSE

The aim of the present clinical trial was to evaluate the efficacy of antimicrobial photodynamic therapy (PDT) for the treatment of halitosis in elderly patients wearing dentures.

METHODS

Elderly patients (>60 years age) wearing complete dentures and diagnosed with halitosis (H₂S levels >112 ppb) were divided into two groups: patients undergoing treatment with tongue scraper and full mouth disinfection (Group I) and patients undergoing treatment with tongue scraper, full mouth disinfection and single application of PDT (Group II). Oral health related quality of life (OHRQoL) was assessed using a 14-point Likert scale used in oral health impact profile (OHIP). The assessment of halitosis was done with the help of a device called Oral Chroma™. Microbial sampling for detection of Porphyromonas gingivalis (P. gingivalis) was performed from the dorsum of the tongue using a sterile swab at baseline and after treatment on day 5, 15 and 30 and quantified using polymerase chain reaction.

RESULTS

Forty elderly patients with halitosis completed the trial. The mean age in Group I and Group II was estimated to be 66.42 years and 67.91 years, respectively. Group II participants also maintained good OHRQoL in the post-operative period that reported statistically significant difference when compared with the control group (p < 0.01). Group II showed significant improvement in H₂S concentration values at final analysis compared to Group-I (p = 0.001). P. gingivalis showed statistically significant reduction on day 5 only with PDT in Group II (p < 0.05).

CONCLUSION

Antimicrobial PDT helped in reducing H₂S gas concentration and improving quality of life in elderly patients wearing dentures. A significant reduction of P. gingivalis occurred only in the short-term follow-up.

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.

Antimicrobial Capacity and Surface Alterations Using Photodynamic Therapy and Light Activated Disinfection on Polymer-Infiltrated Ceramic Material Contaminated with Periodontal Bacteria

This study determined the antimicrobial efficiency of light-activated disinfection (LAD) and photodynamic therapy (PDT) on polymer-infiltrated ceramic network (PICN) material contaminated with three periodontal bacteria and explored if PDT and LAD cause PICN surface alterations. Sixty PICN discs were contaminated with Tannerella forsythia, Porphyromonas gingivalis, and Treponema denticola and randomly divided into five groups (n = 12 samples/each) according to the treatment groups: Group PDT-PDT (630 ± 10 nm diode laser) with methylene blue; Group DL-808 nm diode laser in contact mode without photosensitizer; Group MB-methylene blue without light application; Group CHX-0.12% chlorhexidine digluconate solution and; Group NT-no treatment. Each disc was then placed in tubes containing phosphate buffered saline (PBS) and vortexed for 30 s to remove the remaining bacteria from the discs. A total of 10× serial dilutions were performed followed by plating of 30 μL of suspension on Brucella agar plates. The colony forming units (CFU) were calculated after 72 h. PICN discs with the attached biofilms were used for confocal microscopy investigation for live/dead bacterial viability. A random single sample from each group was selected to study the bacterial adherence and topographical alterations on PICN discs under scanning electron microscope (SEM). The PDT group showed higher reduction for each bacterial species and total counts of bacteria assessed followed by the DL group (p < 0.05). When compared with MB group, the two laser groups were significantly superior (p < 0.05). The MB group did not show significant differences for any bacteria when compared to NT. The bacteria with the CHX group and DL groups appeared dead with few areas of surviving green stained bacteria. The PDT group showed the highest dead cell count (p < 0.05). PDT and DL groups indicate no significant changes on the surface compared to the sterile PICN discs on visual assessment. Photodynamic therapy produced superior periodontal bacteria reduction over the surface of PICN surface. PDT group showed higher reduction for each bacterial species and total counts of bacteria assessed followed by the DL group. Both PDT and DL treatment strategies are effective without producing surface alterations on PICN.

Impact of photodynamic therapy on the push-out bond strength of fiber posts to root dentin: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

This systematic review documents the up-to-date evidence on the efficacy of photodynamic therapy (PDT) on the push-out bond strength of fiber posts cemented to root dentin.

MATERIALS AND METHODS

The focused PICO question was: "What impact does PDT have on the push-out bond strength of fiber posts cemented to root dentin?" This systematic review followed the guidelines and recommendations reported in the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines chart. An electronic search was performed in MEDLINE/PubMed, SCOPUS, Web of Science, and Embase from January 1980 up to and including January 2020. Heterogeneity was calculated for push-out bond strength by means of the Chi-square test and I² statistics. For meta-analyses, if the I² was higher than 50 %, a random effects model was used, otherwise a fixed effects model for I² ≤50 % was applied. A p-value <0.05 was set for significant heterogeneity. Forest plots were computed reporting standard mean differences (SMD) of outcomes and 95 % confidence intervals (CI).

RESULTS

In total, ten studies were included, all of wich demonstrated medium risk of bias. All studies tested the push-out bond strength by means of a universal testing machine with applying a load ranging between 0.5 and 1 mm/min speed. Of the 10 studies, nine (90 %) indicated that PDT had no effect on push-out bond strength of fiber posts to root dentin. Only one study indicated that PDT significantly improved the bond strength when compared with other control groups. The overall mean difference for push out bond strength showed no statistically significant difference between PDT and the control group (SMD = -1.11 [-3.25, 1.02], Z=-1.02, p = 0.305).

CONCLUSION

This systematic review concludes that PDT has no effect on improving the push-out bond strength of fiber posts to root dentin.