To assess and compare the anti-microbial efficacy of 445 nm and 970 nm diode laser on mixed species biofilm of Aggregatibacter actinomycetemcomitans [A.a] and Porphyromonas gingivalis [P.g] cultured on machined pure titanium discs. A total of 65 machined pure titanium discs with no surface modifications with a 10-mm diameter and a 2-mm height were sterilized by autoclaving at 121 °C for 15 min and incubated with the commercially available bacterial strains ATCC(American Type Culture Collection- P.g 33277 and A.a 29522)mixture of Aggregatibacter actinomycetemcomitans(A.a) and Porphyromonas gingivalis(P.g).After a 2-week incubation period with the mixture of bacteria to develop a mixed species biofilm, the discs were divided into three groups: (1) no treatment (control), (2) 445 nm laser (test), (3) 970 nm laser (test). For each laser wavelength (445 and 970 nm), the discs were exposed to 1.0 W and 2.0 W in continuous wave mode for the times points of 15, 30, and 60 s. The antimicrobial efficacy was assessed by qPCR. A significant reduction in the levels of both species of bacteria was observed between control and the laser intervention groups. A higher efficacy for the 445 nm diode laser against Porphyromonas gingivalis and a similar efficacy against Aggregatibacter actinomycetemcomitans was observed as compared to the 970 nm group. 445 nm wavelength represents a potential and effective laser wavelength which can be used for the management of peri-implant infection. The present study findings also need to be further validated through clinical interventional trials.

OBJECTIVE: To assess both the clinical and immunological effectiveness of diode laser therapy when used as an adjunct to non-surgical mechanical therapy in managing peri-implantitis.
METHODS: A cohort of 27 participants, comprising 21 females and 6 males, agreed to take part in this investigation. 37 dental implants with peri-implantitis diagnosis were randomly allocated to either the laser group (n = 19) or the control group (n = 18). Evaluation of peri-implant clinical parameters and collection peri-implant crevicular fluid (PICF) samples occurred at baseline, as well as at 3 and 6-month follow-up intervals. The level of various biomarkers (TWEAK, IL-1β, sclerostin, IL-17, RANKL, OPG and IL-10) within the PICF were quantified using enzyme-linked immunosorbent assay.
RESULTS: Significant time-dependent decreases in clinical and biochemical parameters were detected in both groups compared to the baseline. There were marked differences between the groups in terms of periodontal parameters, except probing depth, and IL-1β, IL-17, sclerostin levels in PICF at 3rd month follow-up. However, no statistically significant difference was detected at 6th month.
CONCLUSIONS: Diode laser seems to be a reliable tool as an adjunct for supporting the nonsurgical mechanical treatment during the early stages of peri-implantitis. Furthermore, the findings suggest that IL-17, sclerostin and IL-1β may serve as promising biomarkers for assessing efficacy of peri-implantitis treatment.
CONCLUSIONS: Based on these outcomes, clinicians may consider the application of adjunctive use of diode laser to non-surgical peri-implantitis treatment to achieve better clinical and immunological improvements than nonsurgical peri-implantitis therapy alone in just early healing period. However, it should be noted that there was no difference between the two methods in the long term.

The purpose of this research was to investigate the effect of toluidine blue (TB) mediated photodynamic therapy (PDT) on the inhibition of lipopolysaccharide (LPS)-induced inflammation in rat gingival fibroblasts through in vitro experiments. Rat gingival fibroblasts were divided into five groups: (1) control, (2) LPS treatment, (3) laser treatment, (4) TB treatment (1.0 µg/mL), and (5) PDT treatment (TB plus laser irradiation at 320 mW/cm2 for 240 s). After 24 h, cell growth activity was measured using MTT assay. The levels of receptor activator for nuclear factor-κB ligand (RANKL) and osteoprotegerin (OPG) in the cell culture supernatant were measured using enzyme-linked immunosorbent assay (ELISA). Nuclear proteins were extracted and the phosphorylation levels of phosphorylated nuclear factor-κB/p65 (p-p65) and phosphorylated inhibitor of nuclear factor-κB (p-IκBα) were determined using Western Blot. MTT results showed no significant difference in cell viability between the groups (P > 0.05). After LPS induction, OPG expression decreased, RANKL expression increased, and the OPG/RANKL ratio decreased, which was different from the control group (P < 0.05). After PDT treatment, OPG expression increased, RANKL expression decreased (P < 0.05), and the OPG/RANKL ratio increased (P < 0.05). Compared to the control group, there was no significant difference in OPG and RANKL expression or the OPG/RANKL ratio (P > 0.05). The activation of NF-κB was closely related to the phosphorylation levels of p-p65 and p-IκBα. LPS significantly up-regulated p-p65 and p-IκBα expression (P < 0.05), while PDT treatment decreased their phosphorylation levels (P < 0.05). TB-PDT treatment can inhibit NF-κB signaling pathway activation, decrease RANKL and OPG expression, and reduce the OPG/RANKL ratio, thereby reducing inflammation and playing a role in periodontitis treatment.

Aim: The study aims to assess the efficacy of rose bengal (RB)-mediated antimicrobial photodynamic therapy (a-PDT) as an adjunct to scaling and root planing in the management of chronic periodontitis patients in terms of clinical parameters like gingival index (GI), probing pocket depth (PPD), clinical attachment level (CAL), and microbiological parameters like total microbial count, total red complex organism count, Porphyromonas gingivalis count, Treponema denticola count, and Tannerella forsythia count. Materials and Methods: In this randomized controlled clinical trial, a total of 30 patients were recruited who met the inclusion criteria. The participants were randomly allocated into group A with scaling and root planning (SRP) alone and group B with SRP + a-PDT. The clinical and microbiological parameters were measured at baseline and at 3-month follow-up. Intergroup and intragroup comparisons were performed using independent t test and paired t test, respectively. Value of p < 0.05 was considered as statistically significant. Results: At 3-month follow-up, group B treated with SRP + a-PDT showed statistically significant reduction in GI (0.58 ± 0.20) and PPD (1.81 ± 0.32 mm), gain in CAL (0.73 ± 0.04 mm), and reduction in total microbial count [2.80 ± 0.08 × 104 colony forming unit (CFU)], total red complex count (0.29 ± 0.14 × 102 CFU), P. gingivalis count (0.43 ± 0.13 × 102 CFU), T. denticola count (0.61 ± 0.04 × 102 CFU), and T. forsythia count (0.59 ± 0.04 × 102 CFU) as compared with group A (p < 0.05). Conclusion: RB-mediated a-PDT as an adjunct to SRP was significantly more effective in improving GI, PPD, and CAL and in reducing microbial count as compared with SRP alone in the management of chronic periodontitis.

UNASSIGNED: Diode laser is one of the most captivating technologies in dental practice. In periodontics, when used at appropriate settings, it possesses the best properties for selective surgical and nonsurgical procedures such as subgingival calculus removal without a thermal change of the root surface, and also provides tissue surface sterilization. However, lasers always produce a certain amount of thermal damage to the soft tissues. Therefore, this study aimed to comparatively evaluate the thermal impact of 980-nm diode laser incisions, when used with irrigation versus nonirrigation systems.
UNASSIGNED: The study was conducted on 24 gingival tissue samples obtained from the goat\'s mandible and maxilla. The samples were divided into two groups of 12 samples each, and laser incisions were given in 4 power settings, using 980-nm diode laser in super short pulse mode, with and without saline irrigation. Martius Scarlet Blue staining technique was used to prepare the histological slides. Then, slides were examined under a research microscope (Olympus CX 21), and the pictures of the slides were taken by mounting the camera onto the microscope mobile mount. The microscopic images hence obtained were analyzed for the depth and width of the incisions, area of carbonization, necrosis, and reversible damage, using the Digimizer image analysis software.
UNASSIGNED: The results of this study demonstrated that the mean incision depth was higher (592.49 ± 180.97, P < 0.05), with less carbonization (25.52 ± 29.21, P = 0.00) and less necrosis (311.63 ± 156.441, P < 0.05) in the laser incisions with irrigation, as compared to the laser incisions given without irrigation system.
UNASSIGNED: Within the limitations of this study, it can be concluded that using an irrigation system causes less collateral damage while maintaining the incising efficiency of the diode laser. Further studies with a higher sample size, controlled irrigation systems, and incision techniques are needed to evaluate the efficiency of diode lasers for the clinical explanation of the results.

BACKGROUND: There is insufficient clinical and microbiological evidence to support the use of diode laser and air-polishing with erythritol as supplements to scaling and root planning(SRP). The aim of the current study is to evaluate the clinical and microbiologic efficacy of erythritol subgingival air polishing and diode laser in treatment of periodontitis.
METHODS: The study encompassed twenty-four individuals seeking periodontal therapy and diagnosed with stage I and stage II periodontitis. Eight patients simply underwent SRP. Eight more patients had SRP followed by erythritol subgingival air polishing, and eight patients had SRP followed by diode laser application. At baseline and six weeks, clinical periodontal parameters were measured, including Plaque Index (PI), Gingival Index (GI), periodontal Probing Depth (PPD), and Clinical Attachment Level (CAL). The bacterial count of Aggregatibacter actinomycetemcomitans(A.A), Porphyromonas gingivalis (P.G) was evaluated at different points of time.
RESULTS: The microbiological assessment revealed significant differences in the count of A.A. between the laser and erythritol groups immediately after treatment, indicating a potential impact on microbial levels. However, the microbial levels showed fluctuations over the subsequent weeks, without statistically significant differences. Plaque indices significantly decreased post-treatment in all groups, with no significant inter-group differences. Gingival indices decreased, and the laser group showed lower values than erythritol and control groups. PPD and CAL decreased significantly across all groups, with the laser group exhibiting the lowest values.
CONCLUSIONS: The supplementary use of diode laser and erythritol air polishing, alongside SRP, represents an expedited periodontal treatment modality. This approach leads to a reduction in bacteria and improvement in periodontal health.
BACKGROUND: This clinical trial was registered on Clinical Trials.gov (Registration ID: NCT06209554) and released on 08/01/2024.

The aim of this study was to evaluate the effectiveness of a laser-assisted in-office tooth bleaching treatment, employing a diode laser (445 nm) using different power and time settings. Two hundred human incisors were collected for evaluating tooth color change (ΔΕ00) and whiteness index in dentistry (ΔWID) following laser-assisted tooth bleaching treatment. The specimens were distributed into 25 groups (n = 8) according to laser output power (0.5-2 W) and duration of irradiation (10-60 s) that was applied. ΔΕ00 and ΔWID were evaluated using a spectrophotometer at three points of time (24 h, 1 week and 1 month after treatments). Three-way ANOVA revealed that power, duration of laser irradiation, and time of measurement after bleaching treatments significantly affected both ΔΕ00 and ΔWID(p < 0.05). Furthermore, laser irradiation increased ΔΕ00 and ΔWID at all applied powers compared to the control group (p < 0.05), but this increase was dependent on the duration of irradiation. Laser irradiation significantly increased ΔΕ00 when the duration of operation was 50-60 s at 0.5-1 W, while at 1.5-2 W was significantly increased when the duration was 30-60 s. ΔWID was significant higher in the laser groups compared to the control group at all powers, except for 0.5 W where it was significant higher when the duration was 50-60 s. The outcomes of the study can help in selecting the suitable power settings and duration of laser exposure to achieve the optimal whitening results while ensuring the safety of the tooth pulp.

BACKGROUND: In recent years, tooth whitening has become one of the most popular ways of achieving the original tooth color. The effect of whitening gel can be improved through heat, light or laser. The bond strength between the enamel and the composite can be reduced through bleaching and laser radiation. The purpose of this study is to assess the shear bond strength of resin composite to enamel after a bleaching process using hydrogen peroxide, with and without a laser (970 nm and 445 nm lasers).
METHODS: This study used 51 extracted anterior teeth without caries that were divided into three groups. A 40% hydrogen peroxide gel was used on the enamel of all teeth. The control group received bleaching without a laser. Both the second and third treatment groups received bleaching with a laser, one with 970 nm and the other with 445 nm. After the bleaching process, all groups had etching, bonding and curing of the composite performed. Lastly, the shear bond strength between the enamel and the composite was measured and the failure modes were recorded. The data were compared using a one-way ANOVA test.
RESULTS: The mean shear bond strength between the enamel and the composite in the 445 nm group three (445 nanometer) was significantly lower than the other groups (p < 0.05). There was no significant difference between the control and the 970 nm groups (p = 0.2).
CONCLUSIONS: According to the laser wavelengths and parameters that were used in this study and the results of this study, office bleaching with a 445 nm laser weakened the shear bond strength between the enamel and the composite.

UNASSIGNED: Contact laser vaporization of the prostate (CVP) for benign prostatic hyperplasia is a widely accepted and safe procedure for elderly patients because of its lower bleeding risks. However, CVP lacks a postoperative pathological examination for prostate cancer. Concomitant prostate biopsy and CVP may complement this disadvantage; however, the risk of bleeding associated with this procedure remains unclear. This study aimed to evaluate the safety of a concomitant prostate biopsy and CVP.
UNASSIGNED: This retrospective study included 106 men who had undergone CVP in Nerima General Hospital. Prostate biopsies and CVP were performed simultaneously on 16 patients. We defined the \"hemorrhage group\" by a >5% decrease in hemoglobin the day after surgery. Preoperative and operative indices were evaluated based on the association with the hemorrhage group.
UNASSIGNED: Participants in the concomitant biopsy group were older (p = 0.001), had larger prostates (p = 0.014), a lower rate of prostate biopsy history (p = 0.046), longer postoperative urinary catheter duration (p = 0.024), and a higher rate of decline in hemoglobin levels the day after surgery (p = 0.023). Patients in the hemorrhage group (n = 20, 18.9%) showed a significantly higher rate of concomitant biopsy and CVP (p = 0.006). Multivariate analysis showed that concomitant prostate biopsy (p = 0.009, odds ratio = 4.61) was the sole statistically significant predictive factor for hemorrhage.
UNASSIGNED: Concomitant prostate biopsy and CVP of the prostate may increase the risk of bleeding.

This study assessed alterations in sensitivity among symptomatic noncarious cervical lesions (NCCLs) following the application of 3 low-level diode laser wavelengths before composite restoration. It analyzed the changes in dentin topography using a scanning electron microscope (SEM).
Nine patients with 36 NCCLs were randomly assigned intra-individually to 4 groups based on the laser wavelength: laser simulation, 445 nm, 660 nm, and 970 nm. Cavity preparation, irradiation, and composite restoration were performed for each lesion. Sensitivity to cold stimuli was recorded using a visual analog scale (VAS) before the intervention (baseline) and at 1 day, 14 days, 1-, 3-, and 6-month. Pulp sensibility was recorded using an electrical pulp tester (EPT) at baseline, before treatment, and at 3- and 6-month. Additionally, an in vitro examination was performed on 12 extracted human molars to yield 12 dentin discs. Each disc was randomly divided into 4 quadrants to receive the same laser wavelengths to determine the diameters of the tubules using SEM. Results were analyzed statistically for clinical studies by the Friedman test, while ANOVA (RM-ANOVA) was conducted in-vitro, followed by the Bonferroni test in the case of significance (P < .05).
VAS readings decreased across all groups, with a significant decrease observed for 660 nm and 970 nm from 14 days to 6-month, while at 445 nm there was a significant decrease at 6-month compared to the control (P < .05). EPT showed a significant decrease in pain threshold levels at 660 nm and 970 nm at 3- and 6-month, while 445 nm showed a significant decrease at 6-month compared to the control (P < .05). The mean tubular diameter at 445 nm decreased, with no significant difference from the control, whereas a significant decrease was found at 660 nm and 970 nm compared to the control (P < .05).
Prior to composite restoration in symptomatic NCCLs, diode lasers with a wavelength of 660 nm showed the highest reduction in sensitivity, followed by 970 nm, whereas 445 nm diode lasers showed the least reduction. Additionally, diode lasers with wavelengths of 660 and 970 nm reduced the width of the dentinal tubules (DT) without inducing melting, as viewed under SEM.