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The aim of this study was to investigate whether simultaneous irradiation at 660 and 808 nm generates different patterns of oxidative/antioxidative activities compared to consecutive irradiation. Primary cultures of gingival keratinocytes and fibroblasts were exposed to a diose laser (660 ± 2 nm and 808 ± 2 nm, 100 mW, 0.09 cm 2 spot area) using double irradiation with the two wavelengths (consecutive or simultaneous) for 6, 10, and 20 s. The two irradiation regimens did not increase cell viability in any of the experimental conditions. Lipid peroxidation was increased after consecutive irradiation in epithelial cells, which was not detected after simultaneous irradiation. After 20s of the simultaneous mode, ROS levels increased, but antioxidative balance decreased. In the fibroblasts, the two double irradiations induced ROS reduction, increase in lipid peroxidation, and improvement of antioxidative balance, mainly after the 20 s irradiation time. In conclusion, simultaneous and consecutive irradiation induced distinct oxidative stress modulation in oral epithelial cells and fibroblasts. The imbalance in the oxidative system observed after longer exposures, allied with the absence of a significant increase in the viability of the two cell types, suggests a contraindication for longer simultaneous irradiation in clinical situations that demand cellular stimulation., (© 2023 The American Society for Photobiology.)

The aim of this study was to evaluate the antiproliferative properties of low-level laser therapy (LLLT) on gingival fibroblasts obtained from calcium channel blocker-induced gingival overgrowth (GO). Gingival fibroblasts of patients with GO were compared to healthy gingival fibroblasts (H). Both cells were exposed to LLLT (685 nm wavelength, 25mW power, diode laser) and compared to those not treated with LLLT. Cell proliferation and viability were measured with MTT assay at baseline and after 24 and 72 h. TGF-β1, CTGF, and collagen Type 1 levels were evaluated with Enzyme-Linked Immunosorbent Assay (ELISA). LLLT significantly decreased the proliferation of GO fibroblasts (p < 0.05) while leading to a significantly higher proliferation in H fibroblasts compared to the untreated cells (p < 0.05). GO cells showed significantly higher CTGF, TGF-β, and collagen Type 1 expression than the H cells (p < 0.05). LLLT significantly reduced CTGF levels in GO cells compared to the control group (p < 0.05). In H cells, CTGF and TGF-β levels were also significantly decreased in response to LLLT compared to the control group (p < 0.05). While LLLT significantly reduced collagen expression in the H group (p < 0.05), it did not significantly impact the GO cells. LLLT significantly reduced the synthesis of the growth factors and collagen in both groups with an antiproliferative effect on the gingival fibroblasts from calcium channel blocker-induced GO, suggesting that it can offer a therapeutic approach in the clinical management of drug-induced GO, reversing the fibrotic changes., (© 2024. The Author(s).)

Background: Modern dentistry has increasingly valued conservative and biologically less invasive clinical practices, seeking to preserve the patients' tissues and natural dental elements. Most extractions in the dental clinic are preceded by periodontal disease that presents bone and gingival tissue loss, compromising the aesthetics as well as the support of dental elements. Objectives: The clinical approach in these cases often involves bone exertion followed by the successful installation of osseointegrated implants. Material and Methods: In this study, a case of extensive periodontal involvement and mobility of dental elements was carried out in a minimally invasive way, using the Er:YAG laser for periodontal decontamination and the hemolasertherapy technique to regenerate adjacent tissues, totaling nine weeks of treatment. Results: Clinical and radiographical improvement of tissue health and complete preservation of dental elements were observed. Conclusion: The patient underwent a follow-up appointment 2 years after the start of treatment when it was still possible to verify the stability of the clinical condition and the tissue gains obtained.

Objective: This study aims to determine and compare the dental pulp and gingival blood flow in patients referred for oropharyngeal radiotherapy (RT) at three different time points: before the start, immediately after, and six months following the completion of RT. The aim is also to evaluate the dependence of the pulp and gingival blood flow on the radiation dose., Methodology: A prospective study included 10 patients referred for intensity-modulated RT (IMRT) in the oropharyngeal region, with at least one intact tooth surrounded by a healthy gingiva. The dose received by each selected tooth and adjacent gingiva was determined according to the map of treatment planning and computer systems. The blood flow measurements were performed using the laser Doppler flowmetry (LDF) method., Results: Comparing vascular flows at three different time points, the median blood flow in the dental pulp showed no statistically significant difference (p=0.325), contrary to gingiva (p=0.011). Immediately after RT completion, the gingival flow significantly increased compared to its starting point (p=0.012). The pulp flow correlated negatively with the radiation dose, whereas a strong correlation was noted 6 months following the RT completion., Conclusions: RT caused a significant acute gingival blood flow increase, followed by a long-term (over six months) tendency to return to the starting levels. The dental pulp blood flow is differently affected by higher radiation doses (over 50Gy) in comparison to lower doses (below 50Gy). During RT planning, considering the possibility of protecting the teeth localized near the Gross Tumor Volume as a sensitive organ is recommended.

Background: Despite modern treatment techniques, radiotherapy (RT) in patients with head and neck cancer (HNC) may be associated with high rates of acute and late treatment-related toxicity. The most effective approach to reduce sequelae after RT is to avoid as best as possible healthy tissues and organs at risk from the radiation target volume. Even small geometric changes can lead to a significant dose reduction in normal tissue and better treatment tolerability. The major objective of the current study is to investigate 3D printed, tooth-borne tissue retraction devices (TRDs) compared to conventional dental splints for head and neck RT., Methods: In the current two-arm randomized controlled phase II trial, a maximum of 34 patients with HNC will be enrolled. Patients will receive either TRDs or conventional dental splints (randomization ratio 1:1) for the RT. The definition of the target volume, modality, total dose, fractionation, and imaging guidance is not study-specific. The primary endpoint of the study is the rate of acute radiation-induced oral mucositis after RT. The quality of life, local control and overall survival 12 months after RT are the secondary endpoints. Also, patient-reported outcomes and dental status, as well as RT plan comparisons and robustness analyzes, will be assessed as exploratory endpoints. Finally, mesenchymal stem cells, derived from the patients' gingiva, will be tested in vitro for regenerative and radioprotective properties., Discussion: The preliminary clinical application of TRD showed a high potential for reducing acute and late toxicity of RT in patients with HNC. The current randomized study is the first to prospectively investigate the clinical tolerability and efficacy of TRDs for radiation treatment of head and neck tumors., Trial Registration: ClinicalTrials.gov; NCT04454697; July 1 st 2020; https://clinicaltrials.gov/ct2/show/record/NCT04454697 .

Radiation-induced fibrosis is recently established as a main reason for osteoradionecrosis of the jaw (ORNJ), anti-eradiation fibrosis drugs achieve satisfactory therapeutic effects. However, the molecular mechanism remain to be fully elucidated. In this study, we found the inhibitory effect of irradiation activated gingival fibroblasts on osteogenic differentiation of human bone mesenchymal stem cells (hBMSCs). Moreover, irradiation-activated-fibroblasts significantly increased miR‑23a expression in hBMSCs. Decreased miR‑23a enhanced osteogenic differentiation of BMSCs, and elevated miR‑23a inhibited this process via directly targeting CXCL12. Finally, exosome released from irradiation-activated-fibroblasts inhibited osteogenic differentiation of BMSCs, and these exosome mediated delivery of miR-23a and further regulated miR-23a/CXCL12 axis in hBMSCs. Therefore, our findings suggest that by transferring miR-23a, exosome secreted by human gingival fibroblasts in radiation therapy serves a vital role in osteogenic differentiation of hBMSCs, which may provide novel clinical treatments for ORNJ., (Copyright © 2020 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Photobiomodulation (PBM) has been shown to improve wound healing by promoting mesenchymal stem cell migration and proliferation. However, it remains unknown whether an 808-nm diode laser can influence human gingival mesenchymal stem cells (HGMSCs), and which dose this works well. In the present study, it was found that PBM could promote the migration of HGMSCs but not the proliferation. Furthermore, PBM could activate mitochondrial ROS, which could elevate the phosphorylation levels of JNK and IKB in HGMSCs, and further activate NF-κB as the nuclear translocation of p65 is elevated. Taken together, these present results indicate that PBM might promote cell migration via the ROS/JNK/NF-κB pathway.

Objective: The aim of this study was to perform a systematic and multifaceted comparison of thermal effects during soft tissue ablation with various lasers and an electroscalpel (ES). Materials and methods: Er:YAG, Er,Cr:YSGG, CO 2 , Diode, Nd:YAG lasers (1 W, pulsed or continuous wave), an ES, and a scalpel (Sc; control), were employed for porcine gingival tissue ablation. Temperature changes during ablation were measured by using an infrared thermal imaging camera and a thermocouple. After ablations, the wounds were observed using stereomicroscopy and scanning electron microscopy (SEM), and histological sections were analyzed. Compositional analysis was also performed on ablated sites by SEM wavelength dispersive X-ray spectroscopy. Results: The surface temperature during irradiation was highest with CO 2 (over 500°C), followed by Diode (267°C) and Nd:YAG (258°C), Er:YAG (164°C), ES (135°C), and Er,Cr:YSGG (85°C). Carbonization was negligible (Er:YAG), slight (Er,Cr:YSGG), moderate (Nd:YAG and ES), and severe (CO 2 and Diode). Under SEM observation, Er:YAG and Er,Cr:YSGG showed smooth surfaces but other devices resulted in rough appearances. Histologically, the coagulated and thermally affected layer was extremely minimal (38 μm in thickness) and free from epithelial collapse for Er:YAG. Compared with other devices, less compositional surface change was detected with Er:YAG and Er,Cr:YSGG; additionally, the use of water spray further minimized thermal influence. Conclusions: Among various power devices, Er:YAG laser showed the most efficient and refined gingival ablation with minimal thermal influence on the surrounding tissues. Er:YAG and Er,Cr:YSGG lasers with water spray could be considered as minimally invasive power devices for soft tissue surgery.

Aim: Diode lasers are commonly used for antimicrobial photodynamic therapy (aPDT). This study aimed to assess the feasibility of transgingival laser irradiation during aPDT and evaluate whether the photosensitizer can be activated., Materials and Methods: Four diode laser settings were assessed for transgingival irradiation: 120 mW, 80 mW, 60 mW, and 40 mW. Fifteen soft-tissue pieces from a pig's lower jaw were prepared. The specimens' thickness was measured and transgingival laser irradiation was performed. A digital power meter measured laser power on the other side of the tissue. The power outcome after staining of the nonbuccal aspect of the tissue with photosensitizer dye was assessed similarly., Results: Transgingival laser irradiation (average soft-tissue thickness: 0.84 ± 0.06 mm) resulted in different power transmission depending on the power settings and photosensitizer. The lowest values were observed with the 40 mW setting and photosensitizer (median 3.3 mW, max. 5.0 mW, min. 2.3 mW, interquartile range 1.2), and the highest at 120 mW without photosensitizer (median 41.3 mW, max. 42.7 mW, min. 38.0 mW; interquartile range 1.5)., Conclusions: This study indicates that transgingival irradiation may be suitable for aPDT, since power transmission through the gingival tissue was observed in all specimens. However, the decrease in laser power caused by both the soft tissue and the photosensitizer has to be taken into account., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background and o bjectives : The light-curing unit is considered an essential piece of equipment in every dental office. This study was conducted to evaluate the effect of Light-Emitting Diodes (LEDs) by the light cure (LC) device on gingival tissues of albino rats histologically and by regarding the expression of P53 and epidermal growth factor receptor (EGFR). Materials and m ethods : Gingival tissues of the rats were exposed to LEDs for 30 s with an interval of 30 s for periods of 2 and 5 min and were examined after two and four weeks of light exposure. After the set time, histological sections were studied and the P53 and EGFR expressions were evaluated immunohistochemically and by molecular methods. Results : Mild hyperplasia and mild inflammatory response were detected in higher rates after two weeks of exposure when compared to 4 weeks postexposure. Whereas fibrosis was found at a higher rate after four weeks than that found after two weeks postexposure, parakeratosis was seen only in the group that was exposed for 5 min to LC and when biopsies were taken after 2 weeks. We found that the immunohistochemical expression of P53 was not changed. Similarly, the alteration of EGFR expression was statistically nonsignificant ( p > 0.05) when compared to the control group. The data obtained from the qRT-PCR reaction was analyzed using the comparative CT (2 - ΔΔCT ) method. Statistically, there was no significant difference in the expression of EGER and P53 gene transcripts. Conclusion s : LED causes no serious alteration in P53 and EGFR expression, and only trivial histopathological changes occurred, most of which recovered after a 4-week interval., Competing Interests: The authors declare no conflicts of interest.

Objective: The aim of this study was to examine effects of recently developed ultraviolet light-emitting diodes (UV LEDs) wavelengths on in vitro growth and gene expression of cultural periodontopathic bacteria, and on viability of experimental gingival fibroblasts. Materials and methods: Porphyromonas gingivalis , Prevotella intermedia , Fusobacterium nucleatum , Aggregatibacter actinomycetemcomitans , and Streptococcus oralis were irradiated by UV LEDs (265, 285, 310, 365, and 448 nm) at 600 mJ/cm 2 and grown anaerobically in vitro . The colony forming units were counted after 1 week. Cell morphology was observed using a scanning electron microscope (SEM). Quantitative real-time polymerase chain reaction was performed to investigate gene expression changes by 310 nm irradiation. Viability of the irradiated human gingival fibroblasts was evaluated using WST-8 assay. Results: Both 265 and 285 nm resulted in the complete death of bacteria and fibroblasts, whereas 310 nm caused partial killing and suppression of bacterial growth and much less damage to the fibroblasts in vitro . Both 365 and 448 nm resulted in no significant change. SEM showed that P. gingivalis cells gradually degraded from day 2 or 3 and were severely destructed on day 5 for 265, 285, and 310 nm. The 310 nm irradiation transiently suppressed the transcripts of SOS response- and cell division-relative genes. Conclusions: Both 265 and 285 nm may induce powerful bactericidal effects and severe fibroblast phototoxicity, and 310 nm may induce partial killing or growth suppression of bacterial cells with much less fibroblast phototoxicity. UV lights may have potential for bacterial suppression, with situations dependent on wavelength, in periodontal and peri-implant therapy.

Gingival melanin hyperpigmentation is an esthetic concern for many individuals. In this study, we compared the standard surgical removal method with two different Er,Cr:YSGG laser settings in order to find the best treatment method. In 33 dental arches, the following three treatment groups were comparatively evaluated: (1) surgical stripping, (2) removal with laser setting 1 (4.5 W, 50 Hz, 100% water, 80% air, 60 μs, 800 μm Tip; MZ8), and (3) laser setting 2 (2.5 W, 50 Hz, 20% water, 40% air, 700 μs, 800 μm Tip; MZ8). We comparatively evaluated pain, patient satisfaction and wound healing, treatment time, and the amount of bleeding. Re-pigmentation was evaluated after 1 and 12 months by Hedin and Dummet pigmentation scores. Laser setting 1 had the best results regarding pain and patient satisfaction, although not statistically significant (P > 0.05). Wound healing results were better using lasers compared to surgical stripping (P < 0.05). Laser setting 1 was a faster procedure with mild amounts of bleeding. The least amount of bleeding was seen with laser setting 2. After 1 month, only two cases of the laser setting 2-treated areas showed an isolated pigmented area in the papilla; at 12 months, the mean Hedin indexes were still less than 2 and mean Dummett index less than 1 in all treatment techniques, with the lowest scores seen in the laser setting 1 sites. Based on our results, Er,Cr:YSGG laser can be more convenient for gingival depigmentation compared to surgical blade. Although not statistically significant, laser setting 1 with shorter pulse duration and higher water spray showed better overall results. However, laser setting 2, with longer pulse duration and less water spray, resulted in better coagulative effects and can be used to control bleeding wherever necessary in clinical practice.

Ionizing radiation can induce genomic lesions such as DNA double-strand breaks whose incomplete or faulty repair can result in mutations, which in turn can influence cellular functions and alter the fate of affected cells and organ systems. Ionizing-radiation-induced sequence alterations/mutations occur in a stochastic manner, which contributes to an increased cancer risk in irradiated individuals. Ionizing radiation exposure, and particularly acute doses at high dose rates (as often observed in radiation accidents), induce alterations in the genome that in part will reflect specific characteristics of the DNA damage response and the repair mechanisms involved. Here, the exome of primary human gingival fibroblasts not exposed or exposed to 0.2, 2, 5, or 10 Gy of x rays was investigated after 16 h of DNA repair for ionizing-radiation-induced mutations. The irradiation effect with varying dose was investigated using three different bioinformatic filters for the analysis of accumulated variants per Mb of genomic DNA and per cytogenetic bands. A highly stringent cutoff of 20-fold coverage was used for all analyses. Comparing exome DNA from irradiated and nonirradiated cells disclosed a characteristic variation of the frequency of ionizing-radiation-induced single-nucleotide variants as well as small insertions and deletions among chromosomes and their subregions. Increases in ionizing-radiation-induced variants with increasing dose were highly significant (p = 2.2 × 10, Kruskal-Wallis test). These results indicate that certain chromosomal regions may be more prone to accumulating particular ionizing-radiation-induced alterations than others, which points to a characteristic metasignature in the irradiated exome.

Objective: The purpose of this study was histological and thermometric examination of soft tissue de-epithelialization using digitally controlled laser handpiece (DCLH) - X-Runner., Background Data: Commonly used techniques for de-epithelialization include scalpel, abrasion with diamond bur, or a combination of the two. Despite being simple, inexpensive and effective, these techniques are invasive and may produce unwanted side effects. It is important to look for alternative techniques using novel tools, which are minimally invasive and effective., Materials and Methods: 114 porcine samples sized 6 × 6 mm were collected from the attached gingiva (AG) of the alveolar process of the mandible using 15C scalpel blade. The samples were irradiated by means of Er:YAG laser (LightWalker, Fotona, Slovenia), using X-Runner and HO 2 handpieces at different parameters; 80, 100, and 140 mJ/20 Hz in time of 6 or 16 sec, respectively. The temperature was measured with a K-type thermocouple. For the histopathological analysis of efficiency of epithelium removal and thermal injury, 3 random samples were de-epithelialized with an HO 2 handpiece, and 9 random samples with an X-Runner handpiece with different parameters. For the samples irradiated with DCLH, we have used three different settings, which resulted in removing 1 to 3 layers of the soft tissue. The efficiency of epithelium removal and the rise of temperature were analyzed., Results: DCLH has induced significantly lower temperature increase compared with HO 2 at each energy to frequency ratio. The histological examination revealed total epithelium removal when HO 2 handpiece was used at 100 and 140 mJ/20 Hz and when DCLH was used for two- and threefold lasing at 80, 100, and 140 mJ/20 Hz., Conclusions: Er:YAG laser with DCLH handpiece may be an efficient tool in epithelium removal without excessive thermal damage.

Gingival overgrowth (GO) is an undesirable result of certain drugs like Cyclosporine A (CsA). Histopathology of GO shows hyperplasia of gingival epithelium, expansion of connective tissue with increased collagen, or a combination. Factors such as age, gender, oral hygiene, duration, and dosage also influence onset and severity of GO. One of the mechanisms behind uncontrolled cell proliferation in drug-induced GO is inhibition of apoptotic pathways, with a consequent effect on normal cell turnover. Our objective was to determine if UV photo-treatment would activate apoptosis in the gingival fibroblast component. Human gingival fibroblast cells (HGF-1) were exposed to 200ng/ml or 400ng/ml CsA and maintained for 3, 6, and 9 days, followed by UV radiation for 2, 5, or 10min (N=6). Naïve (no CsA or UV), negative (UV, no CsA), and positive controls (CsA, no UV) were designated. Prior to UV treatment, growth media was replaced with 1M PBS to prevent absorption of UV radiation by serum proteins, and cells were incubated in growth media for 24h post-UV before processing for TUNEL assay, cell proliferation assays, or immunofluorescence. Data showed a temporal increase in proliferation of HGF-1 cells under the influence of CsA. The 200ng/ml dose was more effective in causing over-proliferation. UV treatment for 10min resulted in significant reduction in cell numbers, as evidenced by counts and proliferation assays. Our study is a first step to further evaluate UV-mediated apoptosis as a mechanism to control certain forms of GO., (Copyright © 2018 Elsevier GmbH. All rights reserved.)

Various flap graft techniques in the treatment of gingival recession have already been reported in the literatures for root coverage. Laser therapy has effects of ablative, hemostatic, and decontamination. Therefore, we performed a meta-analysis of randomized controlled trials (RCTs) to compare the efficacy of flap surgery combined with laser with surgery alone for treating gingival recession. The studies were searched from PubMed, Embase, Web of science, and the Cochrane Central Register of Controlled Trials by two reviewers up to August 2017. The quality of RCTs was assessed by Cochrane Handbook. Data were extracted from studies and analyzed by Review Manager 5.3. 95% confidence interval (CI) and risk ratio (RR) were calculated for dichotomous data. Seven RCTs with 173 patients and 296 teeth were included in the meta-analysis. We found no statistically significant differences between two groups in GRD (gingival recession depth) (P = 0.21), GRW (gingival recession width) (P = 0.92), RES (root esthetic score) (P = 0.21), and CRC (complete root coverage) (P = 0.09). Statistically significant differences were found between two groups in the WKT (width of keratinized tissue) (P < 0.0001) and 1-year follow-up of PD (probing depth) (P = 0.03) and CAL (clinical attachment level) (P < 0.00001). The meta-analysis found that surgery with laser therapy provided clinical advantages in terms of WKT and 1-year follow-up of PD and CAL. However, flap graft associated with laser did not offer additional benefit to root coverage and esthetics in treating gingival recession. More long-term studies are required to assess these parameters.

Background: Interdental papilla is of major importance to patients' orofacial aesthetics, especially regarding anterior teeth as part of the smile's harmony. Loss of gingival tissue, which constitutes interdental papilla, forms what in odontology is called black spaces. This loss, besides affecting the smile's aesthetics, also provokes phonetic and functional damage., Objective: The objective of the authors is to present the result of three clinical cases treated with an innovative technique called hemolasertherapy, which stimulates growth of gingival papilla and thus permanently fills in the black spaces., Methods: The photobiomodulation therapy (PBMT) used a 660 nm diode laser (Laser Duo, MMO-São Carlos, SP, Brazil), punctual, contact mode in two steps: before the bleeding (first PBMT) and immediately after bleeding (second PBMT). Parameters used were power output: 100 mW, CW; diameter tip: 5 mm; spot area: 0.19 cm 2 ; irradiation exposure time per point: 20 sec; 14 points per daily session; total of 2 sessions, with a 1-week interval; E: 2 J per point; E: per daily session, 28 J; irradiance per point: 0.52 W/cm 2 ; fluence per point: 10.4 J/cm 2 . Total in two daily sessions: total energy: 56 J; total fluence: 294.75 J/cm, 560 sec total time. An in vitro preliminary study was simultaneously carried out to demonstrate what could happen at cellular level in hemotherapy clinical cases associated with PBMT laser application., Results: This initial study demonstrated that the blood clot originated from the bleeding provoked in the gingival area is rich in mesenchymal stem cells. PBMT enables preservation, viability, and further differentiation, stimulating the return of gingival stem cells, which would support their survival and differentiation in the blood clot, thus favoring interdental papilla regeneration., Conclusions: Follow-up was done for a time span of 4-5 years and considered excellent with regard to papilla preservation.

Objective: To compare the 6-month clinical efficacy of Er:YAG laser and standard scalpel technique in treating gingival hyperpigmentation., Method and Materials: Patients requesting treatment for moderate to severe gingival hyperpigmentation in the maxilla were enrolled in this split-mouth study. The contralateral maxillary sides were randomly assigned to receive either Er:YAG laser (continuous wavelength of 2,940 nm) with a noncontact tip or the standard scalpel technique. Dummett oral pigmentation index (DOPI) and Hedin melanin index (HMI) were compared at the baseline and at 1 and 2 weeks, and 1, 3, and 6 months following the treatment. Bleeding Index, total treatment time, patient preference, pain perception at the first 3 days, wound healing, and level of satisfaction were also compared. Mann-Whitney test, Kruskal-Wallis test, and chi-square test were used to test the significance between variables. A P value of less than or equal to .05 was considered statistically significant., Results: Of the 22 patients enrolled, 20 completed this study. After assessing DOPI and HMI at 1 and 2 weeks, and at 1-, 3-, and 6-month follow-up appointments, both Er:YAG laser and scalpel were significantly effective in treating gingival hyperpigmentation when compared to baseline (P < .001) but with no statistically significant difference between the two treatment methods (P > .05). More patients preferred the scalpel technique as it was associated with slightly shorter treatment time and less postoperative pain when compared to Er:YAG laser, but with no statistical significance (P > .05). Er:YAG laser sites showed minimal bleeding and more rapid wound healing (P < .001)., Conclusion: Both Er:YAG laser and scalpel technique achieved similar outcomes regarding the efficacy of gingival depigmentation, postoperative pain perception, and the time required for the treatment. Laser therapy requires more advanced technology and is associated with higher financial costs. Therefore, the scalpel technique is still considered the gold standard treatment for gingival depigmentation.

The purpose of this study was to investigate the effect of different high-power energy settings of a neodymium:yttrium-aluminum-garnet (Nd:YAG) laser (1064 nm) on cell viability of human gingival fibroblasts (GFs) and release of transforming growth factor-beta (TGF-β) and vascular endothelial growth factor (VEGF) on these cells. GFs were isolated from human gingival connective tissues during the crown lengthening procedure. GFs were irradiated with different laser parameters as follows: group 1: 1 W (100 mJ, 10 Hz) 10 seconds; group 2: 1.5 W (150 mJ, 10 Hz) 10 seconds; group 3: 2 W (200 mJ, 10 Hz) 10 seconds; group 4: 1 W (100 mJ, 10 Hz) 20 seconds; group 5: 1.5 W (150 mJ, 10 Hz) 20 seconds; and group 6: 2 W (200 mJ, 10 Hz) 20 seconds. Cell viability/cell proliferation was analyzed with XTT (tetrazolium salt, cell proliferation kit) staining. The release levels of TGF-β and VEGF were analyzed by the enzyme-linked immunosorbent assay. No significant differences were observed in the different laser irradiation groups compared to the control group in terms of cell viability (p > 0.05). The release of TGF-β was not affected by different laser irradiation settings (p > 0.05). Only group 6 promoted significantly higher VEGF release from GFs in 24 hours compared to the control group (p ˂ 0.05). These findings suggest that high-power Nd:YAG laser is probably safe but has a very limited effect for wound healing.

Objective: This study evaluated the temperature increase in swine gingival temperature after exposure to light emitted by a Polywave ® LED light curing unit (LCU, Bluephase 20i, Ivoclar Vivadent)., Methods: After local Ethics Committee approval (protocol 711/2015), 40 pigs were subjected to general anesthesia and the LCU tip was placed 5mm from the buccal gingival tissue (GT) close to lower lateral incisors. A thermocouple probe (Thermes WFI, Physitemp) was inserted into the gingival sulcus before and immediately after exposure to light. Real-time temperature (°C) was measured after the following exposure modes were applied: High Power (20s-H, 40s-H, and 60s-H) or Turbo mode (5s-T), either with or without the presence of rubber dam (RD) interposed between the LCU tip and GT (n=10). The presence of gingival lesions after the exposures was also evaluated. Peak temperature (°C) and the temperature increase during exposure over that of the pre-exposure baseline value (ΔT) data were analyzed using 2-way ANOVA followed by Bonferroni's post-hoc test (α=5%). A binary logistic regression analysis determined the risk of gingival lesion development., Results: Without RD, no significant difference in ΔT was observed among 20s-H, 40s-H, and 60s-H groups, which showed the highest temperature values, while the 5s-T exposure showed the lowest ΔT, regardless of RD. RD reduced ΔT only for the 20s-H group (p=0.004). Gingival lesions were predominantly observed using 40s-H, with RD, and 60s-H, with and without RD., Significance: Exposure to a LCU light might be harmful to swine gingiva only when high radiant exposure values are delivered, regardless of the use of RD., (Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.)

Introduction: Mixed outcomes have been found in animal and clinical studies with regard to the use of low-level laser therapy (LLLT) as a modality to accelerate orthodontic tooth movement (OTM). One major reason for the variable findings is the different methodologies and protocols for laser therapy use., Objective: The aim of this study was to determine whether orthodontically moved molars exposed to two different wattages at the same energy density of LLLT exhibited differences in the amount of tooth movement and molecular and histological changes in the adjacent periodontal areas., Methods: An orthodontic force was applied to rat upper first molars exposed to 500mW (EX-500) and 1000mW (EX-1000) of laser application, with a control group (CT) with no laser application. Gene expression in the periodontal ligament (PDL) and histology of the palatal gingiva of the molars were analyzed., Results: There was a statistically significant difference for OTM between EX-500 but not between EX-1000 and CT groups. RANKL and MMP-13 expression levels in the PDL of orthodontically moved molars, however, were increased significantly in laser-exposed groups compared to CT. Early signs of dysplasia were observed in over half of the animals in the EX-1000 group., Conclusions: Our results provide evidence for molecular changes and the potential dysplastic effects of laser on the surrounding soft tissues. Further studies are needed to better identify an optimum laser protocol to maximize the desired effect., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Background: Oral pigmentation, especially in the gingiva poses esthetic problems. Laser therapy has been widely used for cosmetic therapy in dentistry. The aim of the present study was to systematically review the efficacy of surgical laser therapy (SLT) in the management of oral pigmented lesions (OPL)., Materials and Methods: The addressed focused question was "Is SLT effective in the management of OPL?" Databases (MEDLINE via PubMed; EMBASE; Cochrane Central Register of Controlled Trials and Cochrane Oral Health Group Trials Register databases) were searched from 1970 up to and including February 2017., Results: Ten studies were included. The reported number of OPL ranged between 8 and 140. Oral pigmented sites included, gingiva, buccal and labial mucosa, alveolar mucosa and lips. Lasers used in the studies included Q-switched alexandrite, Neodymium-doped yttrium aluminium garnet, diode, Erbium: yttrium aluminium garnet and carbon dioxide laser. Laser wavelength, power output and number of irradiations were 635-10,600nm, 1-10W and 1 to 9 times, respectively. The follow up period ranged from 6 to 24months. All studies reported SLT to be effective in the treatment of OPL. In five studies, recurrence of OPL occurred which ranged from 21.4% to 45%., Conclusions: Lasers are effective in the management of OPL including physiologic gingival pigmentation, smokers' melanosis and pigmentation in Laugier-Hunziker syndrome. Different laser types (CO 2, Er:YAG and Diode) showed comparable outcomes in the treatment of OPL., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: To evaluate for the first time in vivo the effects of methylene blue (MB) photosensitizer dissolved in ethanol in antimicrobial photodynamic therapy (aPDT) as adjuvant periodontal treatment, at plasmatic oxidative stress and vascular behavior in rat model., Methods: Wistar rats were divided into negative control (NC, no periodontitis) and positive control (PC, with periodontitis, without any treatment). The other groups had periodontitis and were treated with scaling and root planing (SRP); SRP+aPDT+MB dissolved in water (aPDT I); SRP+aPDT+MB dissolved in ethanol (aPDT II). The periodontitis was induced by ligature at the mandibular right first molar. At 7/15/30days, rats were euthanized, the plasma was used to determine oxidative stress parameters and gingival tissue for histomorphometric analysis., Results: PC showed higher thiobarbituric acid reactive substances levels in 7/15/30days. aPDT II was able to block the lipid peroxidation, especially between 15th and 30th days. Glutathione reduced levels were consumed in PC, aPDT I and II groups throughout the experiment. aPDT II increased the vitamin C levels which were restored in this group in the 30th day. aPDT II group showed the highest number of blood vessels., Conclusion: In summary, the aPDT with MB dissolved in ethanol provides better therapeutic responses in periodontitis treatment., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Objectives: To evaluate chromosomal damage and cytotoxicity in exfoliated buccal mucosa cells, cells of the tongue and epithelial gingival cells from adults following CBCT scan and to compare the sensitivity of the different exfoliated cells to a same dosage of ionizing radiation., Methods: The study included 46 healthy participants (median age 27 years; age range 23-42 years) who had a CBCT scan. Exfoliated mucosa cells were collected immediately before the CBCT scan and 10 days after. Cells were centrifuged, fixed in the fluid of methanol : glacial acetic acid (3 : 1) and stained using the method of Schiff's reagent and fast green. One observer analyzed all the slides. For interobserver variances, a second observer scored 16 slides chosen from all the subjects. The same set of 16 slides were analyzed once again a month later for intraobserver variances., Results: There is no significant differences for micronucleated cells before and after a CBCT scan in exfoliated buccal mucosa cells (p = 0.476), cells of the tongue (p = 0.884) and epithelial gingival cells (p = 0.362). The frequencies of pyknosis cell and karyolysis cell had significantly increased after CBCT scan in the three groups. No significant difference was found among the three kinds of mucosa cells (p = 0.557). The interobserver (p = 0.624) and intraobserver (p = 0.193) variances were not significant., Conclusions: A CBCT scan may induce cytotoxicity but not chromosomal damage in the oral mucosa cells, including buccal mucosa cells, cells of the tongue or epithelial gingival cells. The sensitivity of the different exfoliated cells to the same dosage of radiation had no statistically significant difference.

Background and Objectives: Increased expression of inflammatory cytokines in the oral cavity has been related to the etiopathogenesis of oral mucositis and to delayed oral mucosal repair. Low-level laser therapy (LLLT) stimulates proliferation and migration of gingival fibroblasts, but the effects of specific inflammatory cytokines on oral mucosal cells and the modulation of these effects by LLLT have not been fully investigated. Therefore, this study investigated the effects of LLLT on oral fibroblasts after being challenged by oral-mucositis-related inflammatory cytokines., Methods: Human gingival fibroblasts were seeded in plain culture medium (DMEM) containing 10% fetal bovine serum (FBS) for 24 hours. Then, cells were kept in contact with inflammatory cytokines (TNF-α, IL-1β, IL-6, and IL-8) in serum-free DMEM for 24 hours. After this period, cells were subjected to LLLT with a diode laser device (LaserTABLE, InGaAsP, 780 nm, 25 mW) delivering energy doses from 0.5 to 3 J/cm 2 . Irradiation was repeated for 3 consecutive days. Twenty-four hours after the last irradiation, cell migration (wound-healing and transwell migration assays), cell proliferation (BrdU), gene expression of COL-I and growth factors (real-time PCR), and synthesis of COL-I (Sirius Red assay) and VEGF (ELISA) were assessed. Data were subjected to two-way ANOVA and Tukey's tests or Kruskall-Walis and Mann-Whitney tests (P < 0.05)., Results: The inflammatory cytokines decreased the migration capacity of gingival fibroblasts. However, a statistically significant difference was observed only for IL-6, detected by transwell assay, where 30% less cells migrated through the pores (P < 0.05) and IL-8, with an increased wound area (116%; P < 0.05), detected by the wound healing method. Cell proliferation was not affected by contact with cytokines, while growth factors and COL-I expression (approximately 80%; P < 0.05), as well as VEGF synthesis (approximately 20%; P < 0.05), were decreased after contact to all tested cytokines. The opposite was seen for total collagen synthesis. LLLT promoted an acceleration of fibroblast migration (30%; P < 0.05) and proliferation (112%; P < 0.05) when delivering 0.5 J/cm 2 to the cells previously in contact with the inflammatory cytokines. Gene expression of VEGF (approximately 30%; P < 0.05), and EGF (17%; P < 0.05), was stimulated by LLLT after contact with TNF-α and IL-6., Conclusion: LLLT can counteract the negative effects of high concentrations of inflammatory cytokines, especially IL-6 and IL-8 on gingival fibroblast functions directly related to the wound-healing process. Lasers Surg. Med. 48:1006-1014, 2016. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)

Chitosan hydrogels containing hydroxypropyl methylcellulose (HPMC) and toluidine blue O were prepared and assessed for their mucoadhesive property and antimicrobial efficacy of photodynamic inactivation (PDI). Increased HPMC content in the hydrogels resulted in increased mucoadhesiveness. Furthermore, we developed a simple In Vitro 3D gingival model resembling the oral periodontal pocket to culture the biofilms of Staphylococcus aureus ( S. aureus ), Aggregatibacter actinomycetemcomitans ( A. actinomycetemcomitans ), and Porphyromonas gingivalis ( P. gingivalis ). The PDI efficacy of chitosan hydrogel was examined against periodontal biofilms cultured in this 3D gingival model. We found that the PDI effectiveness was limited due to leaving some of the innermost bacteria alive at the non-illuminated site. Using this 3D gingival model, we further optimized PDI procedures with various adjustments of light energy and irradiation sites. The PDI efficacy of the chitosan hydrogel against periodontal biofilms can significantly improve via four sides of irradiation. In conclusion, this study not only showed the clinical applicability of this chitosan hydrogel but also the importance of the light irradiation pattern in performing PDI for periodontal disease., Competing Interests: The authors declare no conflict of interest.

Unlabelled: Recent investigations have suggested that antimicrobial photodynamic therapy (aPDT) can be an alternative treatment for the management of periodontal infections. However, currently there is very limited data regarding the photocytotoxicity of this method on human gingival fibroblast (HuGu) cells., Aim: The in vitro optimal concentrations of indocyanine green (ICG) and curcumin as photosensitizers (PSs) and the irradiation time of diode laser emission were evaluated by assessing the photocytotoxicity of the treatment on HuGu cells., Materials and Method: Monolayers of HuGu cells were incubated with various final concentrations of ICG (500, 750, 1000, 1250, 1500, 1750, and 2000μg/ml) and curcumin (3, 4, 5, 10, and 20mM). Three exposure times of the diode laser (30s, 60s, and 2×30s irradiation with an interval of 1min between each) and one of exposure time of 5min for LED were tested; cell viability was determined using neutral red assay. Chlorhexidine (CHX) as a gold standard antimicrobial agent for periodontal disease was considered as a control group., Results: ICG and curcumin significantly reduced HuGu cell viability at concentrations below 1000μg/ml and 10mM, respectively (P<0.01). Cytotoxicity was higher when the cells were treated for 2×30s irradiation with an interval of 1min and then again exposed to the laser for 30s (2% and 0.1%). CHX demonstrated no significant reduction in HuGu cell survival., Conclusion: Photocytotoxicity is influenced by PS concentration, exposure time of PS, and time of irradiation. High doses of ICG and curcumin with lowest exposure time of light source and without cytotoxic effects may be an effective strategy for aPDT as an alternative treatment for periodontal disease., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Ionizing radiation is known to induce genomic lesions, such as DNA double strand breaks, whose repair can lead to mutations that can modulate cellular and organismal fate. Soon after radiation exposure, cells induce transcriptional changes and alterations of cell cycle programs to respond to the received DNA damage. Radiation-induced mutations occur through misrepair in a stochastic manner and increase the risk of developing cancers years after the incident, especially after high dose radiation exposures. Here, the authors analyzed the transcriptomic response of primary human gingival fibroblasts exposed to increasing doses of acute high dose-rate x rays. In the dataset obtained after 0.5 and 5 Gy x-ray exposures and two different repair intervals (0.5 h and 16 h), the authors discovered several radiation-induced fusion transcripts in conjunction with dose-dependent gene expression changes involving a total of 3,383 genes. Principal component analysis of repeated experiments revealed that the duration of the post-exposure repair intervals had a stronger impact than irradiation dose. Subsequent overrepresentation analyses showed a number of KEGG gene sets and WikiPathways, including pathways known to relate to radioresistance in fibroblasts (Wnt, integrin signaling). Moreover, a significant radiation-induced modulation of microRNA targets was detected. The data sets on IR-induced transcriptomic alterations in primary gingival fibroblasts will facilitate genomic comparisons in various genotoxic exposure scenarios.

Objective: The purpose of this study was to evaluate the short- and medium-term effects of low-level laser therapy (LLLT) applied in repeated doses in adults with a healthy periodontium treated by lingual orthodontic appliances., Background Data: Plaque accumulation, in combination with difficulty in removing it in lingual orthodontic patients, can cause gingival inflammation., Methods: Twelve orthodontic patients scheduled for fixed lingual orthodontic treatment were selected. Clinical measurements [visible plaque index (VPI), bleeding on probing (BOP), and probing depth (PD), and collection of gingival crevicular fluid (GCF)], which was used to measure the levels of interleukin-1beta (IL-1β) and tumor necrosis factor alpha (TNF-α), was performed before bonding the lingual device, and at the short-term (1, 2, 3 months) and medium-term (12 months) follow-up appointments. For each patient, quadrant 1 or 2 was randomly chosen for irradiation by a diode laser (λ = 670 nm, 190 mW, 6.05 W/cm(2), 60 sec/ tooth) (Laser Group) and the contralateral quadrant was used as the Control Group., Results: In both studied groups, a slight worsening of the periodontal condition was observed, which was evident at the 3rd month follow-up and which was mainly at the lingual side in the Control Group. The levels of IL-1β in the GCF were significantly increased in the Control Group compared with the Laser Group at the 2nd and 3rd months after bonding. At the 12th month follow-up, an improvement of the inflammation was observed in both groups in the study., Conclusions: LLLT showed short-term effects by preventing a substantial increase in IL-1β levels. At medium-term follow-up, LLLT diminished VPI, BOP, and PD scores.

Gingival augmentation techniques proposed in the international literature do not exclude a surgical component, which determines consequent post-surgical discomfort and results are not always predictable. In recent years, the introduction of laser biostimulation has led to a less invasive approach, particularly in the treatment of periodontally compromised patients, limiting the surgical phase to seriously compromised cases, with regeneration techniques for the restoration of a correct periodontal tissue anatomy. The aim of this in vitro study is to establish the validity of laser biostimulation in order to develop the epithelial keratinized layer of the tissue by stimulating fibroblasts-keratinocytes organotypic cultures and fibroblasts and keratinocytes mono-cultures. We created two groups (test and control), each one composed of 3 fibroblast cultures, 3 keratinocyte cultures and 3 organotypic cultures. We performed laser irradiation of test group with Wiser Doctor Smile Lambda, Flat Top Handpiece, at 50 J/cm2 of fluency with one application every 40 h for a total of 5 applications. Forty-eight h after the last laser application, we investigated the presence and amount of keratins 5 and 8 with citofluorymetric and western blotting analyses. Analyses showed an increase in keratin synthesis in test group cultures, showing a remarkable increase in production of keratin 8 in co-cultures test. Laser biostimulation can considerably enhance keratin synthesis when applied with high energy doses and repeated applications to keratinocytes-fibroblasts co-cultures.

Shockwave therapy is used in medicine due to its ability to stimulate healing processes. The application of orthodontic force evokes an inflammatory reaction resulting in tooth movement. Shockwave therapy might have an effect on both inflammatory and periodonal ligament cytokine profiles. Our aim was to evaluate the fluctuations of different inflammatory cytokines after orthodontic force induction with and without shockwave therapy. An orthodontic appliance was applied between the rats' molars and incisors. In conjunction with the commencement of orthodontic force, the rats were treated with a single episode of 1000 shock waves and the gingival crevicular fluid was collected for 3 days. The expression and concentration of different cytokines was evaluated by a commercial 4-multiplex fluorescent bead-based immunoassay. The level of all cytokines displayed a similar trend in both shockwave-treated and untreated groups; the concentration peaked on the first day and declined thereafter. In all cases, however, the cytokine levels were smaller in the shockwave-treated than in untreated animals; a significant difference was found for sRANKL and borderline difference for IL-6 on Day 1. We conclude that shockwave therapy during the induction of orthodontic tooth movement influences the expression of inflammatory cytokines.

Though the Er:YAG laser (ErL) has been used in periodontal therapy, the irradiated tip damage has not been studied in detail. In this study, the change in the energy output, surface morphology, and temperature of quartz tips was evaluated following contact irradiation. Soft tissue, calculus on extracted human teeth, and porcine bone were irradiated by ErL for 60 min at 14.2 or 28.3 J/cm(2)/pulse and 20 Hz with or without water spray. The energy output ratio declined the most in the calculus group, followed by the bone and soft tissue groups with and/or without water spray. Carbon contamination was detected in all groups, and contamination by P, Ca, and/or other inorganic elements was observed in the calculus and bone groups. The rate of energy output reduction and the degree of surface alteration/contamination is variously influenced by the targeting tissue, temperature elevation of the tip and water spray.

Background and Objectives: Low-power laser irradiation (LPLI) is known to regulate cell proliferation and migration in clinical use. Recent studies have shown that LPLI induces cell death in some certain types of cancer cell lines. However, the cytotoxic selectivity of LPLI for cancer cells is not fully understood. The aim of this study was to compare the cytotoxic effects of LPLI in both human oral cancer OC2 cells and normal human gingival fibroblast (HGF) cells., Materials and Methods: LPLI at 810 nm with an energy density from 10 to 60 J/cm(2) was used to irradiate human oral cancer OC2 cells and normal HGF cells., Results: We found that LPLI significantly diminished cell viability of human oral cancer OC2 cells due to cell cycle arrest at the G1 phase and the induction of cell death but that it had no or little effects on cell cycle progression and death in normal HGF cells. Moreover, the production of reactive oxygen species (ROS) and the loss of mitochondrial membrane potential (MMP) were elevated in human oral cancer OC2 cells compared with the un-irradiated cells. In contrast, these effects remained unchanged in normal HGF cells after exposure to LPLI. LPLI also induced apoptosis in caspase-3 dependent manner in human oral cancer OC2 cells, a mode of action that could be mediated by ROS and mitochondrial damage., Conclusion: Our findings imply LPLI might be a potential therapy for oral cancers., (© 2015 Wiley Periodicals, Inc.)

It has been reported that oxidative stress with reactive oxygen species (ROS) generation is induced by blue light irradiation to a living body. Only limited research has been reported in dental field on the dangers of blue light, mostly focusing on cytotoxicity associated with heat injury of dental pulp. We thus performed an in vivo study on oral tissue exposed to blue light. ROS generated upon blue light irradiation of flavin adenine dinucleotide were measured by electron spin resonance spectroscopy. After blue light irradiation, the palatal gingiva of Wistar rats were isolated. Collected samples were subjected to biochemical analysis of lipid peroxidation and glutathione. Singlet oxygen was generated by blue light irradiation, but was significantly quenched in an N-acetyl-L-cysteine (NAC) concentration-dependent manner. Blue light significantly accelerated oxidative stress and increased the oxidized glutathione levels in gingival tissue. These effects were also inhibited by NAC pre-administration. The results suggest that blue light irradiation at clinical levels of tooth bleaching treatment may enhance lipid peroxidation by the induction of oxidative stress and the consumption of a significant amount of intracellular glutathione. In addition, NAC might be an effective supplement for the protection of oral tissues against blue light irradiation-induced oxidative damage., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Diagnostic imaging delivering low doses of radiation often accompany human mesenchymal stem cells (MSCs)-based therapies. However, effects of low dose radiation on MSCs are poorly characterized. Here we examine patterns of phosphorylated histone H2AX (γH2AX) and phospho-S1981 ATM (pATM) foci formation in human gingiva-derived MSCs exposed to X-rays in time-course and dose-response experiments. Both γH2AX and pATM foci accumulated linearly with dose early after irradiation (5-60 min), with a maximum induction observed at 30-60 min (37 ± 3 and 32 ± 3 foci/cell/Gy for γH2AX and pATM, respectively). The number of γH2AX foci produced by intermediate doses (160 and 250 mGy) significantly decreased (40-60%) between 60 and 240 min post-irradiation, indicating rejoining of DNA double-strand breaks. In contrast, γH2AX foci produced by low doses (20-80 mGy) did not change after 60 min. The number of pATM foci between 60 and 240 min decreased down to control values in a dose-independent manner. Similar kinetics was observed for pATM foci co-localized with γH2AX foci. Collectively, our results suggest differential DNA double-strand break signaling and processing in response to low vs. intermediate doses of X-rays in human MSCs. Furthermore, mechanisms governing the prolonged persistence of γH2AX foci in these cells appear to be ATM-independent.

Aim: The aim of this retrospective multicenter study was to verify the efficacy of Nd:YAG laser in the treatment of periodontal pockets infected by Epstein-Barr Virus (EBV) and Herpes Simplex Virus 1 (HSV1)., Methods: Subgingival plaque samples of 291 Italian periodontal patients were analyzed by Real Time PCR to evaluate the frequency of both viruses before and after Nd:YAG laser-assisted periodontal treatment., Results: Before treatment, EBV and HSV1 were observed in 29.9% and in 3.8% of periodontal patients respectively, while co-infection with both viruses was detected in 1.7% of cases. Periodontal Nd:YAG laser treatment ("Periodontal Biological Laser-Assisted Therapy", PERIOBLAST) produced statistical significant benefits, especially in EBV periodontal infection: 78.2% of EBV positive patients became EBV-negative following treatment., Conclusions: Results of this preliminary study highlight that EBV is found in periodontal pockets more frequently than HSV1, supporting the theory of the potential role of EBV in the onset and progression of periodontal disease. Moreover, our data showed that Nd:YAG laser-assisted periodontal treatment (Perioblast) is also effective in case of viral infection, validating evidences that it represents a successful alternative approach to traditional periodontal protocols.

Background: Radiation technology focuses on delivering the radiation as precisely as possible to the tumor, nonetheless both acute and long-term damage to surrounding normal tissue may develop. Injuries to the surrounding normal tissue after radiotherapy of head and neck cancer are difficult to manage. An animal model is needed to elucidate good treatment modalities. The aim of this study was to establish a rat model where a certain radiation dose gives reproducible tissue reactions in the mandibular area corresponding to injuries obtained in humans., Method: The left mandible of male Sprague Dawley rats was irradiated by external radiotherapy (single fraction 15 Gy, total dose 75 Gy) every second week five times. Endpoint was six weeks after last radiation treatment, and the test group was compared to non-irradiated controls. Morphological alterations of the soft tissues, bone and tooth formation, as well as alterations of salivation, vascularity and collagen content were assessed. An unpaired, non-parametric Mann-Whitney test was used to compare the statistical differences between the groups., Results: Analysis of the soft tissues and mandible within the radiation field revealed severe unilateral alopecia and dermatitis of the skin, extensive inflammation of the submandibular gland with loss of serous secretory cells, hyperkeratinization and dense connective fiber bundles of the gingival tissue, and disturbed tooth development with necrosis of the pulp. Production of saliva and the vascularity of the soft tissues were significantly reduced. Furthermore, the collagen fibril diameter was larger and the collagen network denser compared to non-irradiated control rats., Conclusion: We have established an animal model of radiation injury demonstrating physiological and histological changes corresponding to human radiation injuries, which can be used for future therapeutic evaluations.

Aim: This RCT investigated the effect of non-invasive extracorporeal shockwaves on tooth mobility in orthodontic patients after active treatment., Materials and Methods: Seventy-two adult patients were included in the study. Immediately after active orthodontic treatment, patients were assigned to a treatment or a placebo group based on block randomization. The orthodontic patients were required to be otherwise healthy. The region of interest was the anterior portion of the mandible. The treatment group received a single shockwave treatment with 1000 impulses while the placebo group was treated with an acoustic sham. Tooth mobility was evaluated over a period of 6 months using a Periotest and manual testing. Pocket probing depths, bleeding on probing and the irregularity index were also assessed., Results: Tooth mobility reduced significantly over 6 months in both groups, but shockwaves achieved significantly more rapid reduction on manual testing. Probing depth was significantly reduced while the irregularity index remained stable. Bleeding on probing was significantly reduced in the treatment group. No anti-inflammatory effect could be derived due to possible initial group differences., Conclusions: The mobility of teeth aligned by orthodontic treatment reduces over time. Shockwave treatment appeared to reduce tooth mobility more rapidly., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The erbium-doped yttrium aluminum garnet (Er:YAG) laser is currently used for periodontal soft tissue management with favorable outcomes. However, the process of wound healing after Er:YAG laser (ErL) treatment has not been fully elucidated yet. The aim of this study was to investigate the gingival tissue healing after ErL ablation in comparison with that after electrosurgery (ElS). Gingival defects were created in 28 rats by ablation with ErL irradiation or ElS. The chronological changes in wound healing were evaluated using histological, histometrical, and immunohistochemical analyses. The ErL-ablated gingival tissue revealed much less thermal damage, compared to the ElS. In the ElS sites, the postoperative tissue destruction continued due to thermal damage, while in the ErL sites, tissue degradation was limited and the defects were re-epithelialized early. Heat shock protein (Hsp) 72/73 expression was detected abundantly remote from the wound in the ElS, whereas it was slightly observed in close proximity to the wound in the ErL sites. Hsp47 expression was observed in the entire connective tissue early in the wound healing and was found limited in the wound area later. This phenomenon proceeded faster in the ErL sites than in the ElS sites. Expression of proliferating cell nuclear antigen (PCNA) persisted in the epithelial tissue for a longer period in the ElS than that in the ErL. The ErL results in faster and more favorable gingival wound healing compared to the ElS, suggesting that the ErL is a safe and suitable tool for periodontal soft tissue management.

Low-level laser therapy (LLLT) has been promoted for its beneficial effects on tissue healing and pain relief. As during laser treatment it is possible to irradiate only a small area of the surface body or wound and, correspondingly, of a very small volume of the circulating blood, it is necessary to explain how its photomodification can lead to a wide spectrum of therapeutic effects. To establish the experimental model for indirect irradiation, irradiation with 635 nm was performed on immortalized human gingival fibroblasts (IGFs) in the presence of Porphyromonas gingivalis lipopolysaccharides (LPS). The irradiated medium was transferred to non-irradiated IGFs which were compared with direct irradiated IGFs. The protein expressions were assessed by Western blot, and prostaglandin E2 (PGE2 ) was measured using an enzyme-linked immunoassay. Reactive oxygen species (ROS) were measured by DCF-DA; cytokine profiles were assessed using a human inflammation antibody array. Cyclooxygenase-2 (COX-2) protein expression and PGE2 production were significantly increased in the LPS-treated group and decreased in both direct and indirect irradiated IGFs. Unlike direct irradiated IGFs, ROS level in indirect irradiated IGFs was decreased by time-dependent manners. There were significant differences of released granulocyte colony-stimulating factor (G-CSF), regulated on activated normal T-cell expressed and secreted (RANTES), and I-TAC level observed compared with direct and indirect irradiated IGFs. In addition, in the indirect irradiation group, phosphorylations of C-Raf and Erk1/2 increased significantly compared with the direct irradiation group. Thus, we suggest that not only direct exposure with 635 nm light, but also indirect exposure with 635 nm light can inhibit activation of pro-inflammatory mediators and may be clinically useful as an anti-inflammatory tool., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Oral mucosa is frequently exposed to Herpes simplex virus type 1 (HSV-1) infection and irradiation due to dental radiography. During radiotherapy for oral cancer, the surrounding clinically normal tissues are also irradiated. This prompted us to study the effects of HSV-1 infection and irradiation on viability and apoptosis of oral epithelial cells., Methods: Immortal gingival keratinocyte (HMK) cells were infected with HSV-1 at a low multiplicity of infection (MOI) and irradiated with 2 Gy 24 hours post infection. The cells were then harvested at 24, 72 and 144 hours post irradiation for viability assays and qRT-PCR analyses for the apoptosis-related genes caspases 3, 8, and 9, bcl-2, NFκB1, and viral gene VP16. Mann-Whitney U-test was used for statistical calculations., Results: Irradiation improved the cell viability at 144 hours post irradiation (P = 0.05), which was further improved by HSV-1 infection at MOI of 0.00001 (P = 0.05). Simultaneously, the combined effects of infection at MOI of 0.0001 and irradiation resulted in upregulation in NFκB1 (P = 0.05). The combined effects of irradiation and HSV infection also significantly downregulated the expression of caspases 3, 8, and 9 at 144 hours (P = 0.05) whereas caspase 3 and 8 significantly upregulated in non-irradiated, HSV-infected cells as compared to uninfected controls (P = 0.05). Infection with 0.0001 MOI downregulated bcl-2 in non-irradiated cells but was upregulated by 27% after irradiation when compared to non-irradiated infected cells (P = 0.05). Irradiation had no effect on HSV-1 shedding or HSV gene expression at 144 hours., Conclusions: HSV-1 infection may improve the viability of immortal cells after irradiation. The effect might be related to inhibition of apoptosis.

We demonstrated previously that low-level diode laser irradiation with an indocyanine green-loaded nanosphere coated with chitosan (ICG-Nano/c) had an antimicrobial effect, and thus could be used for periodontal antimicrobial photodynamic therapy (aPDT). Since little is known about the effects of aPDT on periodontal tissue, we here investigated the effect of low-level laser irradiation, with and without ICG-Nano/c, on cultured epithelial cells. Human oral epithelial cells were irradiated in a repeated pulse mode (duty cycle, 10 %; pulse width, 100 ms; peak power output, 5 W). The expression of the developmental endothelial locus 1 (Del-1), interleukin-6 (IL-6), IL-8, and the intercellular adhesion molecule-1 (ICAM-1) were evaluated in Ca9-22 cells stimulated by laser irradiation and Escherichia coli-derived lipopolysaccharide (LPS). A wound healing assay was carried out on SCC-25 cells irradiated by diode laser with or without ICG-Nano/c. The mRNA expression of Del-1, which is known to have anti-inflammatory activity, was significantly upregulated by laser irradiation (p < 0.01). Concurrently, LPS-induced IL-6 and IL-8 expression was significantly suppressed in the LPS + laser group (p < 0.01). ICAM-1 expression was significantly higher in the LPS + laser group than in the LPS only or control groups. Finally, compared with the control, the migration of epithelial cells was significantly increased by diode laser irradiation with or without ICG-Nano/c. These results suggest that, in addition to its antimicrobial effect, low-level diode laser irradiation, with or without ICG-Nano/c, can suppress excessive inflammatory responses via a mechanism involving Del-1, and assists in wound healing.

Background: Surgical resection, radio and chemotherapy, either used singly or in combination, are the three most common modalities used in head and neck cancer treatment. These modalities are effective in eradicating the tumor; they also negatively impact the normal head and neck structures surrounding the tumor. Direct damage to the oral structures (soft and hard tissue) frequently occurs from radio and chemotherapy, and indirect damage may also arise from systemic toxicity., Materials and Methods: This prospective study was designed to analyze the effect of radiotherapy on periodontal parameters in oncology patients prior to irradiation in the head and neck area, compared with 6 months following treatment. The statistical analysis was done using SPSS., Results: The study sample consisted of total 29 patients of head and neck malignancy (M = 17, F = 12), of mean age 45.66 years. Only 22% of patients had various habits (smoking, tobacco chewing, and alcohol consumption) and majority (27.59% patients) had tongue malignancy. All periodontal parameters - oral hygiene index Siller (OHIS), clinical attachment level (CAL), gingival recession (GR), except probing pocket depth (PPD) - were significantly increased after radiotherapy. When comparison was made between doses and fractions, only in mandible statistically significant difference were observed in GR., Conclusion: Although there was no significant change in PPD, there was increased GR, CAL, and plaque index associated with radiotherapy. In this study, 61.5% cases of mandibular teeth and 34.4% cases of maxillary teeth showed attachment loss greater than 0.2 mm. So, all patients with head and neck malignancy should undergo an oral examination before the initiation of cancer therapy with adequate prophylaxis.

Background and Objective: This study evaluated the biostimulatory effect of 660 nm light-emitting diode (LED) as an adjunct in the treatment of experimental periodontitis., Material and Methods: Ninety-six Sprague-Dawley rats underwent experimental periodontitis by placement of a silk ligature followed with or without additive Porphyromonas gingivalis lipopolysaccharide (Pg-LPS) injection. Irradiation with LED light was performed at varying energy densities of 5, 10 and 15 J/cm2, 1 d after debridement and detoxification. Rats were killed at 3, 7 and 14 d after irradiation with LED light, and the effect of irradiation was evaluated by descriptive histology and quantitative measurements of periodontal bone loss, inflammatory infiltration and cellular proliferation., Results: Reduction of inflammation, accelerated collagen deposition and realignment was noted following irradiation with LED light at densities of 10 and 15 J/cm2, and temporary reduction of periodontal bone loss, as well as bundle bone apposition, was noted at day 3 in rats treated with 10 J/cm2 light. The biomodulatory effect was stronger in sites treated with Pg-LPS injection. In sites without Pg-LPS injection, temporary reduction of inflammation was noted in all LED light-irradiated specimens at day 3. No significant change in cellular proliferation was noted in any LED light-treated group., Conclusions: LED light (660 nm) with an energy density of 10 J/cm2 appeared suitable as an adjunct modality for periodontitis by temporarily reducing inflammation, facilitating collagen realignment and bundle bone deposition. Future studies will aim to amplify the biostimulatory effect of LED light by adding a supplementary medium or repeated irradiation., (© 2012 John Wiley & Sons A/S.)

Background: The potential beneficial effects of extremely low frequency pulsed and sinusoidal electromagnetic fields have been shown on many tissues. Gingival epithelium plays an important role in immunosurveillance of the periodontal tissues. The epithelium acts as a mechanical barrier through cell junctions such as E-cadherin., Objectives: Investigation of the effects of extremely low frequency magnetic fields on gingiva., Material and Methods: Twenty-seven male Wistar albino rats were used. The rats were divided into three groups: control group (n = 9), SEMF group (n = 9), PEMF group (n = 9). The SEMF and PEMF (pulse time: 25 µsn, pulse frequency: 50 Hz) groups were subjected to 1.5 mT, 50 Hz, exposure 6 h a day, 5 days a week for 28 days in methacrylate boxes. The gingival tissue pieces processed for routine histological and immunohistochemical examination and tissue sections were stained with H-E and Masson trichrome. In addition, E-cadherin and type IV collagen expressions were examined immunohistochemically., Results: Intraepithelial lymphocytes and proliferation of epithelial cells increased in both electromagnetic field groups. The over-expressions of E-cadherin on gingival epithelium was detected in the PEMF and SEMF groups. The expression level of type IV collagen was not significant between the control and electromagnetic field treated groups, except for a significant increase in the basal cell layer of the PEMF group, as compared to the control and SEMF groups., Conclusions: PEMF and SEMF have a local pro-inflammatory effect on gingiva, leading to an increase in E-cadherin level but not type IV collagen. Both PEMF and SEMF can be used as a supportive device in the treatment of gingival diseases, especially those which lead to defects in the epithelial barrier.

Heat shock protein-27 (HSP27) is a member of the small HSP family which has been linked to the nuclear factor-kappa B (NF-κB) signaling pathway regulating inflammatory responses. Clinical reports have suggested that low-level light therapy/laser irradiation (LLLT) could be an effective alternative treatment to relieve inflammation during bacterial infection associated with periodontal disease. However, it remains unclear how light irradiation can modulate the NF-κB signaling pathway. We examined whether or not 635 nm irradiation could lead to a modulation of the NF-kB signaling pathway in HSP27-silenced cells and analyzed the functional cross-talk between these factors in NF-κB activation. The results showed that 635 nm irradiation led to a decrease in the HSP27 phosphorylation, reactive oxygen species (ROS) generation, I-κB kinase (IKK)/inhibitor of κB (IκB)/NF-κB phosphorylation, NF-κB p65 translocation and a subsequent decrease in the COX-1/2 expression and prostaglandin (PGE(2) ) release in lipopolysaccharide(LPS)-induced human gingival fibroblast cells (hGFs). However, in HSP27-silenced hGFs, no obvious changes were observed in ROS generation, IKK/IκB/NF-κB phosphorylation, NF-κB p65 translocation, nor in COX-1/2 expression, or PGE(2) release. This could be a mechanism by which 635 nm irradiation modulates LPS-induced NF-κB signaling pathway via HSP27 in inflammation. Thus, HSP27 may play a role in regulating the anti-inflammatory response of LLLT., (© 2012 Wiley Periodicals, Inc. Photochemistry and Photobiology © 2012 The American Society of Photobiology.)

Background and Objectives: State of the art for use of the fiber guided diode laser in dental therapy is the application of bare fibers. A novel concept with delivery fiber and exchangeable fiber tips enables the use of tips with special and optimized geometries for various applications. The aim of this study is the comparison of different focusing fiber tips for enhanced cutting efficacy in oral surgery., Material and Methods: For this purpose various designs of tip geometry were investigated and optimized by ray tracing simulations. Two applicators, one with a sphere, and another one with a taper, were realized and tested on porcine gingiva (diode laser, 940 nm, 5 W/cw; 7 W/modulated). The cutting depth and quality were determined by light microscope. Histological sections of the cuts were prepared by a cryo-microtome and microscopically analyzed to determine the cut depths and thermal damage zones., Results: The simulations show that, using a sphere as fiber tip, an intensity increase of up to a factor of 16.2 in air, and 13.2 in water compared to a bare 200 µm fiber can be achieved. Although offering high focusing factor in water, the cutting quality of the sphere was rather poor. This is probably caused by a derogation of the focusing quality due to contamination during cutting and light scattering. Much better results were achieved with conically shaped fiber tips. Compared to bare fibers they exhibit improved handling properties with no hooking, more regular and deeper cuts (5 W/cw: 2,393 ± 468 µm, compared to the cleaved bare fiber 5 W/cw: 711 ± 268 µm). The thermal damage zones of the cuts are comparable for the various tips and fibers., Conclusions: In conclusion the results of our study show that cutting quality and efficiency of diode laser on soft tissue can be significantly improved using conically shaped fiber tips., (Copyright © 2012 Wiley Periodicals, Inc.)

Objective: To evaluate the genotoxic effects of x-rays on gingival and buccal epithelial cells during panoramic dental radiography using the micronucleus test., Method and Materials: Eighty otherwise healthy subjects who required a diagnostic panoramic radiograph and met the selection criteria were included in the study. Epithelial cells were obtained from the maxillary anterior gingiva and buccal mucosa by gentle scraping with a wooden spatula immediately before exposure and again 10 days after exposure. Cytologic preparations were made according to the Papanicolaou staining method and analyzed under a light microscope for micronucleus count., Results: The mean ± SD micronucleus count of gingival epithelial cells was 1.08 ± 0.76 before radiographic exposure and 1.6 ± 0.93 after exposure. This increase was statistically significant (P < .05). Similarly, there was an increase in the postexposure micronucleus count in the buccal mucosa, but this increase was not significant (P > .05). A significant correlation was observed between the age of subjects and micronucleus count, although no such correlation was found between sex and micronucleus count., Conclusion: Although radiation-related effects from panoramic radiography were reduced compared with full-mouth intraoral periapical radiographs or radiotherapy, the results of this study show that genotoxic effects do take place. Thus, radiographs should be taken with adequate protection measures and only when the potential benefit outweighs the potential risk.