The effects of ozone application on genotoxic damage and wound healing in bisphosphonate-applied human gingival fibroblast cells

Ozone infiltration as an adjunctive treatment to piezoelectric surgery in the management of medication-related osteonecrosis of the jaws: case series of 29 patients

PURPOSE

Medication-related osteonecrosis of the jaws has been reported to be associated with bisphosphonate and RANKL inhibitor medications. This prospective clinical study aimed to assess the outcomes of pre-operative ozone infiltration therapy in patients with established MRONJ.

METHODS

The treatment protocol for ozone applications were designed as 20 applications ozone infiltration therapy followed by surgical interventions of necrotic tissue debridement using piezoelectric surgery instruments. The evaluation of the results based on the clinical and radiologic specifications considering the necrotic lesion reduction and healing. The study included 31 lesions in 29 patients. The mean follow-up was 23.6 months.

RESULTS

25 lesions out of 31 healed totally without any remissions. The outcomes were not affected by any variables such as gender, age, type of pharmacological treatment, lesion location, and MRONJ staging. The statistically significant results were found among the clinical condition of the patients (p = 0.01) and administration route of medications (p = 0.004). Healing was significantly less in patients that received intra-vascular administrations. Clinical conditions of the patients were divided as osteoporosis, oncologic, and arthritis. Significantly better results were obtained in osteoporosis patients. 38% of the population experienced spontaneous sequestration with signs of improvements and the surgical interventions were canceled. According to the results, total healing of MRONJ lesions was seen in 79% patients (81% lesions).

CONCLUSION

Ozone therapy and debridement with Piezoelectric surgery can be considered as a safe and beneficial adjunctive treatment alternative for osteonecrosis lesions in cases of established MRONJ.

Apoptosis Regulation in Dental Pulp Cells and PD-1/PD-L1 Expression Dynamics Under Ozone Exposure - A Pilot Approach

This study aimed to determine the effect of ozone on the expression of Bax and Bcl-2 genes in dental pulp cells. Additionally, the programmed cell death protein 1, programmed death-ligand 1, and CD200 antigens were determined in lymphocytes to assess their surface expression. Dental pulp cells were cultured from extracted healthy third molars and characterized as dental pulp stromal cells. Gene expression of Bcl-2 and Bax was analyzed at 0 s, 6 s, and 12 s of ozone exposure using real-time PCR. Lymphocytes from dental pulp were subjected to ozone exposure for 12 s and PD-1, PD-L1, and CD200/CD200R expression was analyzed by flow cytometry. Upon exposure to ozone for 6 s, the Bcl-2 expression decreased significantly to -0.09, and at 12 s, it increased significantly to 0.3. Bax gene expression level increased significantly to 0.188 after 6 s exposure, and at 12 s, to 0.16. Lymphocytes exposed to ozone for 12 s showed minimal changes in PD-1, PD-L1, and CD200/CD200R expression levels, indicating that oxidative stress does not impact the signaling pathways regulating these molecules. The significant upregulation of Bcl-2 at 12 s highlights the cells' effort to protect themselves from prolonged oxidative stress, possibly tipping the balance toward cell survival and tissue repair. However, the absence of changes in PD-1 and PD-L1 expression on lymphocytes under oxidative stress suggests that these molecules are not sensitive to oxidative stress in this context.

Ozone Therapy as an Adjuvant in the Treatment of Periodontitis

The current study aimed to assess the efficacy of ozone therapy in the treatment of stage II and stage III periodontitis. This prospective split-mouth study selected patients who were diagnosed with either stage II or stage III periodontitis. All patients were treated with scaling and root-planing (SRP) on the control side and SRP with ozone therapy on the test side. Probing depth (PD), clinical attachment loss (CAL), O'Leary plaque index (PI), and bleeding on probing (BOP) scores were recorded at baseline and six weeks after the SRP treatment. A total of 46 patients were selected for this study, including 31 males and 15 females. All periodontal variables (PD, CAL, PI, and BOP) showed significant changes (p < 0.0001) from baseline to six weeks. Moreover, significant changes (PD = 0.0001, CAL = 0.0001, PI = 0.042 and BOP = 0.0001) were also observed between the control and test sides. Gender showed no significance on periodontal variables (p > 0.05) except PD on the test side (p = 0.030). In addition, periodontal stages and grades showed no significant changes (p > 0.05) in any periodontal variables on both sides. Ozone therapy significantly improves the periodontal condition compared to SRP treatment alone. However, the stages and grades of periodontitis do not influence the outcome of ozone therapy.

Menaquinone-4 prevents medication-related osteonecrosis of the jaw through the SIRT1 signaling-mediated inhibition of cellular metabolic stresses-induced osteoblast apoptosis

Long-term usage of bisphosphonates, especially zoledronic acid (ZA), induces osteogenesis disorders and medication-related osteonecrosis of the jaw (MRONJ) in patients, thereby contributing to the destruction of bone remodeling and the continuous progression of osteonecrosis. Menaquinone-4 (MK-4), a specific vitamin K2 isoform converted by the mevalonate (MVA) pathway in vivo, exerts the promotion of bone formation, whereas ZA administration suppresses this pathway and results in endogenous MK-4 deficiency. However, no study has evaluated whether exogenous MK-4 supplementation can prevent ZA-induced MRONJ. Here we showed that MK-4 pretreatment partially ameliorated mucosal nonunion and bone sequestration among ZA-treated MRONJ mouse models. Moreover, MK-4 promoted bone regeneration and inhibited osteoblast apoptosis in vivo. Consistently, MK-4 downregulated ZA-induced osteoblast apoptosis in MC3T3-E1 cells and suppressed the levels of cellular metabolic stresses, including oxidative stress, endoplasmic reticulum stress, mitochondrial dysfunction, and DNA damage, which were accompanied by elevated sirtuin 1 (SIRT1) expression. Notably, EX527, an inhibitor of the SIRT1 signaling pathway, abolished the inhibitory effects of MK-4 on ZA-induced cell metabolic stresses and osteoblast damage. Combined with experimental evidences from MRONJ mouse models and MC3T3-E1 cells, our findings suggested that MK-4 prevents ZA-induced MRONJ by inhibiting osteoblast apoptosis through suppression of cellular metabolic stresses in a SIRT1-dependent manner. The results provide a novel translational direction for the clinical application of MK-4 for preventing MRONJ.

In Vitro Cytotoxicity of Antiresorptive and Antiangiogenic Compounds on Oral Tissues Contributing to MRONJ: Systematic Review

BACKGROUND

Invasive dental treatment in patients exposed to antiresorptive and antiangiogenic drugs can cause medication-related osteonecrosis of the jaw (MRONJ). Currently, the exact pathogenesis of this disease is unclear.

METHODS

In March 2022, Medline (Ovid), Embase (Ovid), Scopus, and Web of Science were screened to identify eligible in vitro studies investigating the effects of antiresorptive and antiangiogenic compounds on orally derived cells.

RESULTS

Fifty-nine articles met the inclusion criteria. Bisphosphonates were used in 57 studies, denosumab in two, and sunitinib and bevacizumab in one. Zoledronate was the most commonly used nitrogen-containing bisphosphonate. The only non-nitrogen-containing bisphosphonate studied was clodronate. The most frequently tested tissues were gingival fibroblasts, oral keratinocytes, and alveolar osteoblasts. These drugs caused a decrease in cell proliferation, viability, and migration.

CONCLUSIONS

Antiresorptive and antiangiogenic drugs displayed cytotoxic effects in a dose and time-dependent manner. Additional research is required to further elucidate the pathways of MRONJ.

Evaluation of the Effects of Topical Application of Chlorhexidine, Ozone, and Metronidazole on Palatal Wound Healing: A Histopathological Study

ABSTRACT

This study aimed to evaluate the effects of chlorhexidine, metronidazole, and ozone application on the healing of palatal wounds in diabetic rats. A defect in the form of a 4 mm-diameter wound was created on the palatal mucosa of 84 adult female Wistar albino rats, which were randomly divided into 4 groups: control, chlorhexidine, metronidazole, and ozone groups. The animals were euthanized after 3, 6, and 10 days, and wound closure was histologically assessed. On day 3, polymorphonuclear leukocytes were significantly higher in the control group than in the chlorhexidine and ozone groups (P < 0.05). Fibrosis was higher in the ozone group than in the control and chlorhexidine groups (P < 0.05). Vascular endothelial growth factor was higher in the metronidazole and ozone groups than in the control group (P < 0.05). On day 6, the quantity of polymorphonuclear leukocytes was higher in the control, metronidazole, and chlorhexidine groups than in the ozone group (P < 0.05). Vascular endothelial growth factor was higher in the ozone group than in the control, chlorhexidine, and metronidazole groups (P < 0.05). On day 10, Vascular endothelial growth factor was higher in the control, chlorhexidine, and metronidazole groups than in the ozone group (P < 0.05). The authors concluded that the use of chlorhexidine, ozone, and metronidazole pastes resulted in enhanced wound healing, as determined histologically. The authors suggest that ozone supplementation can be an alternative therapy to chlorhexidine in impaired wound healing in diabetes mellitus.

Could radial extracorporeal shock wave therapy have an effect on wound healing in clinical practice by creating genotoxic damage? An in vitro study in mouse fibroblasts

Objectives: This study aims to evaluate wound healing effects of in vitro radial extracorporeal shock wave (rESW) application on mouse fibroblasts and whether the cytotoxic effect of extracorporeal shock wave (ESW) was due to a possible genotoxic effect.

Patients and methods: After creating an in vitro wound healing model in L929 mouse fibroblast culture, fibroblasts were stimulated with a frequency of 3 Hz, and 100, 250, 500, 1,000 and 1,500 pulses shock waves were applied. Energy flux densities ranging from 0.01 to 0.23 mJ/mm2 (14.3 MPa) at a constant pressure level of 0.5 and 1 bar were applied. Wound healing, cell viability, and genotoxicity were evaluated at 24 and 48 h.

Results: All shot numbers for both pressures significantly reduced cell viability (p<0.05). For both 0.5 and 1 bar pressures, in both intervals, the rate of wound healing decreased, regardless of the number of shots (p<0.05). In vitro genotoxic damage was detected at both 0.5 and 1 bar pressures, in both time intervals, regardless of the number of shots. The genotoxic damage increased from 24 to 48 h.

Conclusion: The study results suggest that, when ESWT is applied in this in vitro experimental setup, cell viability decreases and wound healing is delayed under all conditions. Furthermore, genotoxic damage can be prevented by using shots below 1,000 pulses. Therefore, while investigating the therapeutic effect of ESW therapy in vitro, the upper limit for the number of shots should be 1,000 pulses.

Therapeutic candidates for keloid scars identified by qualitative review of scratch assay research for wound healing

The scratch assay is an in vitro technique used to analyze cell migration, proliferation, and cell-to-cell interaction. In the assay, cells are grown to confluence and then ‘scratched’ with a sterile instrument. For the cells in the leading edge, the resulting polarity induces migration and proliferation in attempt to ‘heal’ the modeled wound. Keloid scars are known to have an accelerated wound closure phenotype in the scratch assay, representing an overactivation of wound healing. We performed a qualitative review of the recent literature searching for inhibitors of scratch assay activity that were already available in topical formulations under the hypothesis that such compounds may offer therapeutic potential in keloid treatment. Although several shortcomings in the scratch assay literature were identified, caffeine and allicin successfully inhibited the scratch assay closure and inflammatory abnormalities in the commercially available keloid fibroblast cell line. Caffeine and allicin also impacted ATP production in keloid cells, most notably with inhibition of non-mitochondrial oxygen consumption. The traditional Chinese medicine, shikonin, was also successful in inhibiting scratch closure but displayed less dramatic impacts on metabolism. Together, our results partially summarize the strengths and limitations of current scratch assay literature and suggest clinical assessment of the therapeutic potential for these identified compounds against keloid scars may be warranted.

High Efficacy of Ozonated Oils on the Removal of Biofilms Produced by Methicillin-Resistant Staphylococcus aureus (MRSA) from Infected Diabetic Foot Ulcers

Ozone has a high wound healing capacity and antibacterial properties and can be used as a complementary treatment in infections. Methicillin-resistant S. aureus (MRSA) is the most common pathogen found in infected diabetic foot ulcers. Most of MRSA are resistant to several classes of antibiotics and, therefore, there is a need for new, effective, and well-tolerated agents. Thus, we aimed evaluate the antimicrobial and antibiofilm potentials of ozonated vegetable oils against MRSA strains isolated from diabetic foot ulcers. Six ozonated oils were produced with concentrations of ozone ranging from 0.53 to 17 mg of ozone/g of oil. The peroxide values were determined for each oil. Ozonated oils content on fatty acid was determined by gas chromatography equipped with a flame ionization detector. The antimicrobial susceptibility testing was performed by the Kirby–Bauer disk diffusion method and the effect of ozonated oils on biofilm formation ability and on established biofilms was investigated. In general, the content in identified unsaturated fatty acid in oils decreased with the increase of ozonation time and, consequently, the peroxide value increased. Most bacterial strains were inhibited by ozonated oil at a concentration of 4.24 mg/g. Ozonated oils had moderate to high ability to remove adhered cells and showed a high capacity to eradicate 24 h old biofilms. Our results show promising use of ozonated oils on the treatment of infections, in particular those caused by multidrug-resistant MRSA strains.

Ozone Therapy for Oral Palatal Ulcer in a Leukaemic Patient

Chemotherapy usually causes complications affecting several tissues such as oral mucosa. In this case report, a soft palate oral ulcer caused by chemotherapy was treated by ozone gas. This kind of treatment is known for its antimicrobial, regenerative and analgesic proprieties. The results show a complete resolution of the lesion within 2 weeks of treatment. Ozone therapy demonstrates greater effectiveness with respect to this kind of oral lesion compared to traditional therapy. Considering this evidence, ozone therapy should be considered as a useful tool for the adjuvant therapy of oral complications in oncologic patients.

Effect of ozone and diode laser (635 nm) in reducing orthodontic pain in the maxillary arch—a randomized clinical controlled trial

The effect of ozone, diode laser irradiation, and presence of teeth crowding/spacing on pain perception in orthodontic patient was tested. Overall, 76 patients [55 women and 21 men; age 35.1(6.4) years] who met the inclusion criteria participated in the study. Immediately after fixed orthodontic appliance placement, the patients were exposed to a pain relief treatment (one single session) using either 635-nm diode laser (SmartM, Lasotronix, Warsaw, Poland) or ozone therapy (OzoneDTA, Apoza, New Taipei City, Taiwan) by placing the handpieces in the area of each teeth apex and interdental papillae, from the maxillary right first molar to the maxillary left first molar. Subjects were divided into three groups: control group (G1, n = 26), ozone (G2, n = 26, exposed to ozone therapy, generator probe type 3, working time per point 5 s, 23 points, application time 1 min and 55 s), and laser group (G3, n = 25, exposed to continuous mode diode laser, 400 mW, handpiece diameter 8 mm, spot area 0.5024 cm2, power density per second 1.59 W/cm2, dose 2 J per point, time: 5 s per point, 23 points, total energy per session 46 J, application time 1 min and 55 s). The level of teeth crowding was assessed using the Lundstrom indicator. The patients received a questionnaire for pain assessment (the Numeric Rating Scale, NRS-11, grade level 0–10) and recorded at 7 time points (1 h, 6 h, and 1, 2, 3, 4, and 5 days ) after the fixed orthodontic appliance placement. The mean pain values for the diode laser, ozone, and control group were 3.6 (1.31) (95% CI, 2.95–4.25), 5.25 (3.37) (95% CI, 3.52–6.98), and 5.75 (2.40) (95% CI, 4.69–6.81), respectively. We observed lower pain values in the diode laser group compared to the control group (p = 0.0237). The use of ozone in this study did not result in significant pain reduction in comparison to control (p = 0.8040) and laser groups (p = 0.1029). There were no differences in pain perception between patients with crowded teeth and non-crowded teeth in each group (G1, p = 0.66, G2, p = 0.86, G3, p = 0.24). The use of 635-nm diode laser led to decreased pain perception; however, ozone and presence of teeth crowding/spacing did not affect the pain perception in orthodontic patients during the first 5 days after the fixed orthodontic appliance placement.

The effects of ozone therapy on periodontal therapy: A randomized placebo-controlled clinical trial

OBJECTIVES

The aim of this randomized split-mouth clinical trial was to evaluate the effects of ozone therapy on clinical and biochemical parameters of moderate to severe generalized periodontitis patients after non-surgical periodontal therapy.

METHODS

A total of 36 moderate to severe generalized periodontitis patients were included in the study. The patients were systemically healthy and 18 to 64 years of age. Periodontal parameters, including plaque index (PI), gingival index (GI), probing depth (PD), percentage of bleeding on probing, percentage of pockets deeper than 5 mm and clinical attachment level (CAL), and percentage of ≥3 mm CAL, were evaluated at baseline and 3 months following periodontal therapy. All participants were treated non-surgically. Topical gaseous ozone was applied into periodontal pockets twice a week for 2 weeks during active periodontal therapy. Gingival crevicular fluid pentraxin-3 (PTX-3), interleukin-1β (IL-1β), and high sensitivity C-reactive protein (Hs-CRP) were evaluated. All statistical data were analyzed using SPSS software.

RESULTS

Total of 36 participants completed the study (18 males, 18 females). PI, GI, PD, percentage of bleeding on probing, percentage of pockets deeper than 5 mm and CAL, and percentage of ≥3 mm CAL were improved, and there were no significant differences between the two sides. All inflammatory parameters, PTX-3, Hs-CRP, and IL-1, were reduced at 3-month follow-up. Only the decrease in PTX-3 levels between baseline and 3-month follow-up was statistically significant.

CONCLUSIONS

Ozone therapy did not have any additional effect on periodontal parameters. All cytokines were reduced after periodontal therapy. Only PTX-3 levels were significantly lower at ozone sites compared to those at the control sites.

Effect of topical ozonetherapy on gingival wound healing in pigs: histological and immuno-histochemical analysis

OBJECTIVES

In this study, the effects of ozonetherapy on secondary wound healing were evaluated histologically and immuno-histochemically.

MATERIAL AND METHODS

Material and Methods: 8 healthy pigs were used in this study. Six wounds with 10 mm in diameter were created through the punch technique on the palatinal gingiva of each pig. Ozone gas was applied on only 3 wounds (test group) and the remaining 3 were left to natural healing (control group). Biopsy samples were taken from one of the wounds in each group on the third day, from another wound of each group on the seventh day, and from another one on the tenth day. Routine histological analysis and immuno-histochemical staining were performed to investigate transforming growth factor-beta (TGF-β) and (VEGF) expressions.

RESULTS

Results: No statistical difference was found between the test and control groups in terms of collagen fibers, epithelial formation and inflammation scores. A VEGF expression found in the test group was statistically higher than control group samples taken on the 3rd and 7th day. There was no statistical difference between the test and control groups in terms of TGF-β expression on any of the sampling days.

CONCLUSIONS

Conclusion: The topical application of ozone gas could be effective in the early stages of wound healing by increasing the amount of VEGF expression. Clinical Relevance: Topical application of ozone gas may be effective in the early stages of oral wound healing.

Effects of Laser Photobiomodulation and Ozone Therapy on Palatal Epithelial Wound Healing and Patient Morbidity

OBJECTIVE

The aim of this study was to compare the effects of laser photobiomodulation (PBM) and topical ozone therapy on the reepithelialization of palatal donor site wounds through clinical assessment and computer-aided image analysis and to assess the patient morbidity following free gingival graft (FGG) surgeries.

MATERIAL AND METHODS

Thirty-six patients requiring FGG were randomly allocated into three groups: laser group (n = 12), ozone group (n = 12), and control group (n = 12). Epithelialization was evaluated by applying 3% hydrogen peroxide (H₂O₂) to the wound area and also measured by using digital image analysis (ImageJ). Bland-Altman plots were used for assessing agreement between H₂O₂ and ImageJ measurements. Parameters in relation to patient morbidity were assessed by using visual analog scale (VAS) on the first 3, 7, 14, and 30 days postoperatively.

RESULTS

At day 14, statistically significant smaller wounds were observed with digital image analysis in the ozone group as compared with the control group (p = 0.034). However, intergroup comparison of the remaining wound area evaluated by the clinician using the H₂O₂ method did not reveal any significant differences (p > 0.05). Nonetheless, according to Bland-Altman analysis, the lower and upper limits showed a moderate agreement between the two measurement methods. The mean VAS sores exhibiting postoperative discomfort was observed to be significantly higher in the control group compared with the laser group (p = 0.002) and ozone group (p < 0.001) at day 7.

CONCLUSIONS

Adjunctive ozone therapy could have a significantly beneficial effect on the acceleration of palatal wound healing following FGG procedures. Both PBM and ozone treatment modalities reduced postoperative discomfort as compared with spontaneous healing.

Clinical antibacterial effectiveness and biocompatibility of gaseous ozone after incomplete caries removal

OBJECTIVES

To evaluate local effect of gaseous ozone on bacteria in deep carious lesions after incomplete caries removal, using chlorhexidine as control, and to investigate its effect on pulp vascular endothelial growth factor (VEGF), neuronal nitric oxide synthase (nNOS), and superoxide dismutase (SOD).

MATERIALS AND METHODS

Antibacterial effect was evaluated in 48 teeth with diagnosed deep carious lesion. After incomplete caries removal, teeth were randomly allocated into two groups regarding the cavity disinfectant used: ozone (open system) or 2% chlorhexidine. Dentin samples were analyzed for the presence of total bacteria and Lactobacillus spp. by real-time quantitative polymerase chain reaction. For evaluation of ozone effect on dental pulp, 38 intact permanent teeth indicated for pulp removal/tooth extraction were included. After cavity preparation, teeth were randomly allocated into two groups: ozone group and control group. VEGF/nNOS level and SOD activity in dental pulp were determined by enzyme-linked immunosorbent assay and spectrophotometric method, respectively.

RESULTS

Ozone application decreased number of total bacteria (p = 0.001) and Lactobacillus spp. (p < 0.001), similarly to chlorhexidine. The VEGF (p < 0.001) and nNOS (p = 0.012) levels in dental pulp after ozone application were higher, while SOD activity was lower (p = 0.001) comparing to those in control pulp.

CONCLUSIONS

Antibacterial effect of ozone on residual bacteria after incomplete caries removal was similar to that of 2% chlorhexidine. Effect of ozone on pulp VEGF, nNOS, and SOD indicated its biocompatibility.

CLINICAL RELEVANCE

Ozone appears as effective and biocompatible cavity disinfectant in treatment of deep carious lesions by incomplete caries removal technique.