Is low level laser therapy or ozone therapy more effective for bone healing? Understanding the mechanisms of HIF-1α, RANKL and OPG

Ozone therapy in dentistry: An overview of the biological mechanisms involved (Review)

At low medically-relevant concentrations, ozone serves as an oxidant with a wide spectrum of antimicrobial activity and the ability to promote healing and reduce inflammation. Despite providing therapeutic benefits in a range of diseases, certain adverse effects and contraindications of ozone treatment must be considered. These are primarily related to toxicity from inhalation and systemic types of administration and can be avoided by following relevant guidelines and recommendations. Ozone therapy has been implemented in a number of fields of dentistry and the most commonly used formulations for the oral cavity are gaseous ozone, ozonized water and ozonized oil. The biological mechanisms underlying the molecular effects of ozone have been increasingly reported, but currently remain largely unknown. The aim of the present review was to provide an overview of the mechanisms involved in ozone interaction with dental tissues. The present review focused on relevant evidence regarding the effect of ozone on dental tissues, including periodontal structures, dental cells, enamel and dentine, considering in vitro studies in addition to animal and human studies. A variety of biological mechanisms acting through multiple biochemical target pathways were reported to be responsible for the therapeutic effects of ozone. The main beneficial effects of ozone occurred in the following domains: antimicrobial activity, remineralization and microstructural changes of hard dental tissues, immunomodulation and biostimulation of dental and periodontal cells. Additional research could provide further insights into the use of ozone, increase its use for broader clinical applications and assist in the selection of targeted protocols.

Ozone Improved Bone Dynamic of Female Rats Using Zoledronate

The aim of this study was to analyze the effect of ozone (OZN) therapy on the dynamics of bone tissue in ovariectomized rats treated with zoledronic acid (ZOL). Female Wistar rats aged 6 months (n = 110) were subjected to bilateral ovariectomy (OVX). At month 3 post-OVX, 10 animals were euthanized to characterize the bone tissue architecture using microtomography (micro-CT). The remaining animals were divided into two groups: ZOL group, administered with ZOL (100 μg/kg body weight); saline (SAL) group (0.45 mL of SAL solution), both for 28 days. At month 3 post-treatment, 10 animals from each group were euthanized to characterize the bone architecture using micro-CT. The remaining animals were divided into the following groups: ZOL (n = 20), ZOL + OZN (n = 20); SAL (n = 20), and SAL + OZN (n = 20). The animals in ZOL + OZN and SAL + OZN groups were intraperitoneally administered with OZN (0.7 mg/kg body weight) once every 2 days. On days 30 and 60, six animals from each group were euthanized for analysis and structural characterization of bones in the femoral head and spine. Some samples of the femoral neck were subjected to biomechanical tests, while some samples were analyzed under a laser confocal microscope. The other samples collected from the femoral neck and spine were analyzed for area of neoformed bone and used for performing inflammatory cell and osteocyte counts. Data were submitted to statistical analysis considering a significance level of p < 0.05. Bone volume percentage and osteocyte and inflammatory cell counts were upregulated in the femoral head region of the ZOL + OZN group. Biomechanical analysis of the femoral neck revealed that the modulus of elasticity was similar between the ZOL and ZOL + OZN groups but differed significantly between the SAL and SAL + OZN groups. The positive areas for calcein and alizarin in the ZOL and ZOL + OZN groups were higher than those in the SAL and SAL + OZN groups. This suggested a positive synergistic effect of OZN and ZOL on the maintenance of bone mass and restoration of bone tissue vitality in ovariectomized rats.

A Comparison Between Low-Level Laser Therapy and Intra-articular Ozone Injection in Knee Osteoarthritis Treatment: A Randomized Clinical Trial

Introduction: Knee osteoarthritis (KOA) is a common degenerative joint disease, causing deformity, pain and a limited joint range of motion. Modification of the lifestyle and an exercise training program are the cornerstone of treatment. Alternative therapies such as laser or ozone are commonly used, but there is not any comparative study of low-level laser therapy (LLLT) versus ozone therapy. The aim of the study was to compare the efficacy and safety of the LLLT versus ozone in patients with KOA. Methods: In this single-blinded randomized clinical trial, 60 patients with KOA were assigned to LLLT or ozone groups (n=30). The First basic pain severity, the Western Ontario and McMaster Universities Arthritis Index (WOMAC) score and physical function were determined. Then in the LLLT group, the patients were provided with 12 sessions of LLLT. In the ozone group, 6 sessions of intra-articular injection of ozone were organized (in each session a mixture of 10 mL of bupivacaine 0.25% with 15 mL of ozone 30 μg/mL). In the middle and at the end of the intervention period, we reassessed the joint pain and physical function and the degree of improvement compared between the two groups. Results: In the middle and at the end of the treatment period in both groups, the joint pain decreased significantly. The same as pain, the self-administrated WOMAC score and the range of joint motion improved significantly in both groups. All of these variables exposed more improvement in the ozone group patients. Conclusion: The study showed that both LLLT and ozone are acceptable non-invasive methods in the non-surgical treatment of KOA. Compared to LLLT, the ozone was more effective. These methods must be considered in any patient who is not suitable for surgical interventions or does not experience enough improvement in symptoms following long periods of common exercise training programs.

Photodynamic therapy effect of morpholinium containing silicon (IV) phthalocyanine on HCT-116 cells

In this study, we investigated the in vitro potential of axially 1-morpholiniumpropan-2-ol disubstituted silicon (IV) phthalocyanine (SiPc) which was synthesized previously, on HCT-116 cells as a photodynamic therapy (PDT) agent. The singlet oxygen and photodegradation quantum yields of SiPc were calculated using UV-vis spectrophotometer. The cytotoxic and phototoxic effects of SiPc were evaluated by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay. Annexin V-FITC/PI double staining kit, cell cycle kit, and mitochondria membrane potential (ΔΨm) assay kit with JC-1 were used to indicate the cell death pathway. Caspase-3 and β-catenin protein expressions were evaluated by western blotting. The singlet oxygen and photodegradation quantum yields of SiPc were calculated as 0.73 and 3.64 × 10^-4 in DMSO. The cell viability assays showed that IC₅₀ value of SiPc did not reach to 100 μM without irradiation. However, excellent phototoxicity was observed in the presence of SiPc upon light irradiation. The cells undergoing early/late apoptosis significantly increased in the presence SiPc at 5 μM upon light irradiation. Besides, the proportion of cells at S and G2/M phase increased. Moreover, mitochondria membrane potentials significantly decreased at 1 and 5 μM of SiPc with light irradiation. While caspase-3 expression increased, β-catenin expression significantly decreased on HCT-116 in the presence of SiPc (p < 0.01). The results indicated that the PDT could be related to apoptosis and Wnt/β-catenin signaling pathway. Based on our findings, SiPc exhibited a significant PDT effect on HCT-116 cells therefore, worthy of more detailed study.