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

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 Therapy in Medicine and Dentistry: A Review of the Literature

Ozone has been successfully used in medicine for over 100 years due to its microbiological qualities. Its powerful oxidation impact, which results in the production of free radicals, and its ability to cause the direct death of nearly all microorganisms is the basis for its bactericide, virucide, and fungicide properties. Ozone also has a medicinal impact that speeds up blood flow and aids wound healing. Ozone may be applied as a gas or dissolved in water for medical purposes. Despite the benefits of using ozone therapeutically, concerns about its use in dentistry still exist. We aimed to provide a summary of the current uses of ozone in medicine and dentistry. An electronic search was performed for all English scientific papers published between 2012 and 2023 using PubMed, Cochrane, and Google Scholar search engines. Ozone, clinical applications, medicine, and dentistry were the search terms used. Seventy full-text articles describing the use of ozone therapy in medicine and dentistry were included in the present review. Ozone has shown several beneficial effects in the medical field. However, despite the encouraging in vitro evidence, the clinical use of ozone in dentistry has not yet been demonstrated as highly effective.

Efficacy of antiseptics and chemomechanical methods for dentin caries lesions: A systematic review with GRADE approach

Objectives

Selective caries removal aims to remove carious tissue in deep dentin lesions. However, a discussion stands on the value of antiseptics and chemomechanical adjuvant methods to reduce the bacterial load on residual caries lesions. This systematic review has addressed two main clinical questions to compare the antimicrobial efficacy of available methods using (1) antiseptic or (2) chemomechanical agents before restoring dentin carious lesions.

Methods

We included randomized and non-randomized controlled trials (RCTs/ NRCTs). We searched eight databases from inception to October 2021. Paired reviewers independently screened studies, extracted data, and assessed the risk of bias. The primary outcome was the reduction in the number of total bacterial in dentin, whereas secondary outcomes were reduction in the number of Lactobacillus and Streptococcus. We used the ratio of ratio of post-treatment to baseline means between two interventions in the logarithmic scale as a proper effect measure. Certainty of evidence was assessed with the Grading of Recommendations, Assessment, Development and Evaluation approach.

Results

We included 14 RCTs and 9 NRCTs, with nine interventions. Regardless the method, the number of bacteria at baseline was similar or exceeded that after the intervention, particularly in NRCTs. The evidence was inconclusive for most comparisons. Among antiseptic agents, chlorhexidine (CHX) resulted in an average of 1.14 times [95% confidence interval (CI): 1.08-1.21] more total bacterial than photodynamic therapy in RCTs. Among NRCTS, the natural agents resulted in five times more total bacterial than CHX (95% CI: 2-11). For chemomechanical methods, the control resulted in eight times (95% CI: 4-17) more total bacterial than Carisolv (SHAA).

Conclusions

The certainty of the evidence was very low for all comparisons showing uncertainty whether one treatment could be more effective than another for dentin disinfection. So far, exclusively removing soft carious dentin would be enough to reduce the bacterial count.

Fluoride varnish, ozone and octenidine reduce the incidence of white spot lesions and caries during orthodontic treatment: randomized controlled trial

This randomized, parallel, controlled trial assessed the effect of fluoride varnish, ozone and octenidine on white spot lesions (WSLs) and caries during orthodontic treatment. Patients were enrolled between 1st September 2017 and 31st August 2020 at initiation of orthodontic treatment in Department of Interdisciplinary Dentistry Pomeranian Medical University in Szczecin, Poland. All participants were randomly assigned to four study and one control groups using number random generator. However, investigators were not blinded due to the nature of the study. Groups I, II, III, IV had professional cleaning and varnishing (5% NaF) every 4 weeks. Groups II and IV had in-office ozone therapy before varnishing, groups III and IV received domestic octenidine mouthrinse. Group K had no professional hygienic or prophylactic procedures. WSLs were assessed at T0 and then every 4 weeks (T1-T4) and caries-at T0 and T4. The specific objective was to assess the influence of fluoride varnish, ozone and octenidine on the incidence of white spot lesions and caries during orthodontic treatment. The primary outcome of this report was the highest number of WSLs in group K and the lowest percentage of patients with WSLs in group IV. Each group comprised 30 randomized participants; they were all analyzed. No WSLs were found at T0, but they were stated in all groups at T4. The numbers of patients with WSLs significantly increased between T0-T4 in groups I and K. Group IV had the lowest percentage of patients with WSLs in T1-T4. WSLs in group IV were found no earlier than at T2. Group K had the highest percentage of WSLs at T4: 26%. At T0 all the groups had DMFs above 0 with a significant increase at T4. No side effects of the introduced prophylaxis were observed in any group. Caries is an important problem of fixed orthodontic treatment. Even an extremely intensive prophylaxis could not completely prevent WSLs and caries. Simultaneous application of fluoride varnish, ozone gas exposure and octenidine appears to have a beneficial effect in limiting the development of WSLs.Trial registration: NCT04992481.

Antimicrobial Effect of Ozone Therapy in Deep Dentinal Carious Lesion: A Systematic Review

Aim

This systematic review aimed to answer the following focused question: Is ozone therapy more effective in reducing microbial count as compared to conventional methods in deep dentinal carious lesion?

Objective

The purpose of this systematic review was to perform a review on the effectiveness of ozone therapy in reduction of microbial count in deep dentinal carious lesion. Study eligibility criteria, participants, and interventions: The inclusion criteria comprised studies that compared effect on microbial count in deep dentinal carious lesion after treatments with ozone and other disinfectants in primary or permanent teeth in randomized clinical trials.

Materials and methods

This review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRIMSA) guidelines. The searched databases included Medline (via PubMed), Cochrane, and Google scholar. Articles published until 29 February 2020 without year restriction but only in English language were included.

Results

The search resulted in 359 published studies. After removal of duplicate studies and full-text analysis, seven studies were selected. Overall, the results demonstrated the promising effects of ozone therapy in reduction of microbial count as compared to other disinfectant.

Conclusions

Within the limitations of this review, it can be asserted that the ozone therapy is effective in reduction of microbial count in deep dentinal carious lesion.

Clinical significance

Ozone therapy can be a useful tool to reduce the microorganisms in deep dentinal carious lesion.

How to cite this article

Badhe H, Kalaskar R, Balasubramanian S, et al. Antimicrobial Effect of Ozone Therapy in Deep Dentinal Carious Lesion: A Systematic Review. Int J Clin Pediatr Dent 2022;15(S-2):S252-S260.

Treatment of symptomatic, deep, almost cariously exposed lesions using ozone

The aim of this controlled randomized crossover study was to assess post-treatment pain and the need for root canal treatment after the use of a traditional caries removal method followed by restoration, or after an ozone method of more conservatively managing the deep caries and a restoration. 84 participants (42 males and 42 females, mean age ± SD = 23.9 ± 2.0 years) were randomly allocated to receive either a traditional (n = 42, 21 males and 21 females) or ozone (n = 42, 21 males and 21 females) method. The ozone method only differed from the traditional method by leaving the deep leathery caries on the pulpal floor and then treating this with 20 s of ozone from the healozone X4 (Curozone, Germany). All caries was removed in the traditional group. A conventional glass ionomer cement (Riva Self Cure High Viscosity, SDI, Australia) was placed followed by a bonded composite resin restoration (Filtek Z250 Universal Restorative, 3 M ESPE, USA) in each cavity. The visual analogue scale was used to assess pain scores before treatment and after 24 h. The participants were then followed up for 2 years to assess the need for root canal treatment. Statistical significance levels were set at α ≤ .05. Both groups were associated with significant reduction of pain scores 24 h after treatment (p < .0001). The ozone treatment was associated with less pain 24 h after treatment (p < .0001) and less need for root canal treatment (p = .014), after 2 years follow up, than the conventional treatment. In conclusion, treatment of symptomatic, deep carious lesions by ozone following partial removal of caries was accompanied with less pain and occurrence of RCT after treatment compared to traditional complete caries removal.

Application of Selected Nanomaterials and Ozone in Modern Clinical Dentistry

This review is an attempt to summarize current research on ozone, titanium dioxide (TiO₂), silver (Ag), copper oxide CuO and platinum (Pt) nanoparticles (NPs). These agents can be used in various fields of dentistry such as conservative dentistry, endodontic, prosthetic or dental surgery. Nanotechnology and ozone can facilitate the dentist’s work by providing antimicrobial properties to dental materials or ensuring a decontaminated work area. However, the high potential of these agents for use in medicine should be confirmed in further research due to possible side effects, especially in long duration of observation so that the best way to apply them can be obtained.

Antibiofilm effect of ozonized physiological saline solution on peri-implant-related biofilm

BACKGROUND

Removal of dental plaque and local application of local chemical adjuncts, such as chlorhexidine (CHX), have been used to control and treat peri-implant disease. However, these methods can damage the surface properties of the implants or promote bacterial resistance. The application of ozone as an adjunctive treatment represents a new approach in the management of peri-implantitis. Thus, the purpose of this study was to evaluate the antimicrobial effect of ozonized physiological saline solution in different concentrations against oral biofilms developed on titanium surface.

METHODS

Single and multi-species biofilms of Porphyromonas gingivalis, Fusobacterium nucleatum, and Streptococcus oralis were formed on titanium specimens for 5 days in anaerobic conditions. Biofilms were treated with ozonized saline solution at different concentrations (25, 50, and 80 μg/NmL), for 30 seconds and 1 minute. CHX (0.12%) and saline solution (0.89% NaCl) were used as positive and negative controls, respectively. Bacterial viability was quantified by colony forming units (CFU mL^-1 ), and biofilm images were acquired by confocal laser scanning microscopy (CLSM). Data were analyzed by parametric test (ANOVA) with Tukey post-hoc test (P < 0.05).

RESULTS

Ozonized saline solution showed antibiofilm activity at a concentration of 80 μg/NmL for 30 seconds and 1 minute, reducing, mainly, Porphyromonas gingivalis viability, with 2.78 and 1.7 log₁₀ CFU mL^-1 of reduction in both single and multi-species biofilms, respectively, when compared to the control (saline), whereas CHX reduced 1.4 and 1.2 log₁₀ CFU mL^-1 .

CONCLUSION

Ozonized saline solution has antibiofilm activity, with better effect when applied for 1 minute at 80 μg/NmL, being a promising candidate therapy for the treatment of peri-implant diseases.

Effectiveness and Safety of Ozone Therapy in Dental Caries Treatment: Systematic Review and Meta-analysis

OBJECTIVE

This systematic review and meta-analysis aimed to investigate the effectiveness and safety of ozone therapy for treating dental caries.

METHODS

We searched for randomized controlled trials (RCTs) in 8 databases, from inception to April 4, 2020 (MEDLINE, EMBASE, CENTRAL, LILACS, Bibliografia Brasileira de Odontologia, ClinicalTrials.gov, WHO, and OpenGrey). Primary outcome measures were antimicrobial effect and adverse events. We used the Cochrane risk of bias tool to evaluate methodological quality of included RCTs and GRADE approach to evaluate the certainty of the evidence. We used the Review Manager software to conduct meta-analyses.

RESULTS

We included 12 RCTs comparing ozone therapy with no ozone, chlorhexidine digluconate, fissure sealants (alone and added to ozone), and fluoride. Considering primary outcomes, ozone therapy showed (a) lower reduction in the bacterial number than chlorhexidine digluconate in children (mean difference [MD]: -5.65 [-9.79 to -1.51]), but no difference was observed in adults (MD: -0.10 [-1.07 to 0.88]); (b) higher reduction in the bacterial number than sealant (MD: 12.60 [3.86-21.34]), but no difference was observed after final excavation (MD: -0.00 [-0.01 to 0.01]). Regarding safety of ozone therapy, results from individual studies presented no adverse events during or after treatment. Most of these results are imprecise and should be interpreted with caution because of clinical and methodological concerns, small sample size, and wide confidence interval, precluding to determine the real effect direction.

CONCLUSION

Based on a very low certainty of evidence, there is not enough support from published RCTs to recommend the use of ozone for the treatment of dental caries. Well-conducted studies should be encouraged, measuring mainly the antimicrobial effects of ozone therapy at long term and following the recommendations of the CONSORT statement for the reporting of RCTs.

Influence of ozone application in the stepwise excavation of primary molars: a randomized clinical trial

OBJECTIVES

The aim of this randomized, controlled, three-arm parallel-group, double-blinded clinical trial was to investigate the clinical and microbiological effects of the ozone application in stepwise excavation of primary molars.

MATERIALS AND METHODS

This study was conducted in in vivo conditions with 105 lower primary molars that had deep caries lesions. The teeth were randomly divided into three groups: (I) control group, conventional stepwise excavation with no disinfectants; (II) CHX (positive control) group, 2% chlorhexidine digluconate; and (III) experimental group, ozone application. Dentine samples were collected at 4 different time points (T0, at the first appointment, after partial removal of carious dentin; T1, at the first appointment, after applying disinfection procedure; T2, at the second appointment - at the end of the 4-month period - immediately after the removal of the temporary restoration; T3, at the second appointment, after the final excavation) for the microbiological analysis of mutans streptococci and lactobacilli and the total number of colony-forming units. Clinical changes including dentin color, humidity, and consistency were recorded. Data were analyzed using the Mann-Whitney U test, Friedman test, and chi-squared test (p = 0.05).

RESULTS

The dentin became harder and drier after 4 months in all the groups. There was a gradual reduction in the total number of microorganisms in all the three groups. Bacterial reduction was greater in the CHX group compared to the ozone group (p = 0.002) and was greater in the ozone group compared to the control group (p = 0.015) after 4 months (control, 78%; CHX, 93%; ozone, 82%).

CONCLUSION

Stepwise excavation of primary teeth provided successful outcomes in all the groups. Moreover, CHX, due to its practicality and cost-effectiveness, can be effectively used with one- or two-step indirect pulp therapies.

CLINICAL RELEVANCE

Usage of cavity disinfectants in the stepwise excavation procedure contributes to the reduction of bacterial population in the cavity, which may allow the avoidance of the second step of the indirect pulp therapy for primary teeth.

Ozone ultrafine bubble water induces the cellular signaling involved in oxidative stress responses in human periodontal ligament fibroblasts

Periodontitis is a chronic inflammatory disease caused by oral microorganisms in the subgingival biofilm. Stable aqueous ozone ultrafine bubble water (OUFBW) has recently begun to be used as an antiseptic in the treatment of periodontitis. The effectiveness of OUFBW is thought to depend on the bactericidal actions of dissolved ozone exerted via its oxidizing effect. On the other hand, the effects of ozone on the periodontal tissues are largely unknown. In this paper we examined the cellular responses after OUFBW treatment. Human primary periodontal ligament fibroblasts (hPDLFs) or Ca9-22 human gingival epithelial cells were treated with OUFBW or UV-inactivated OUFBW. The production of reactive oxygen species (ROS), the activation of mitogen-activated protein kinase (MAPK) and the nuclear factor-kappa B (NF-κB) activation were analyzed. The transcript profiles of hPDLFs after OUFBW treatment were also analyzed by RNA sequencing (RNA-seq). Our results showed that OUFBW induces oxidative stress by generating ROS, which, in turn, activated the MAPK pathway. OUFBW triggered activation of c-Fos, a major component of the transcription factor activator protein 1 (AP-1), and also nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2), which possessed a high sensitivity to oxidative stress. The results of RNA-seq analysis revealed that the numerous genes involved in oxidative stress responses or MAPK signaling pathway were up-regulated after OUFBW treatment. Investigation of the signaling pathways activated by OUFBW highlights another aspect of the biological roles of OUFBW, in addition to its bactericidal activity, in the treatment of periodontitis.

Effectiveness of the ozone application in two-visit indirect pulp therapy of permanent molars with deep carious lesion: a randomized clinical trial

OBJECTIVES

The aim of this randomized, three-arm parallel, single-blinded clinical trial was to evaluate the clinical and microbiological effectiveness of the ozone application in two-visit indirect pulp therapy.

MATERIALS AND METHODS

One hundred five lower first molar teeth with deep caries lesion were included and randomly assigned three groups to apply the two-visit indirect pulp therapy. Treatment procedure was applied without any disinfectant (control), with 60-s 2% chlorhexidine digluconate (CHX) or 60-s ozone application. In four different stages (after initial excavation, ozone/CHX application before the temporary restoration, 4 months later immediately after removing temporary restoration, and final excavation), dentin humidity, consistency, and color properties were recorded to evaluate the clinical characteristics of the tissue, and standard dentin samples were collected for the microbiological analysis of mutans streptococci, lactobacilli, and the total number of colony-forming units. The data were analyzed by using Mann-Whitney U test for multiple comparisons.

RESULTS

The remaining dentin became harder, drier, and darker after 4 months in all groups. However, CHX and ozone application were statistically better than the control group (p < 0.05). There was a gradual decrease in the total number of microorganisms in all groups. While cavity disinfectant applications were improved the antibacterial efficacy (control, 79.11%; CHX, 98.39%; ozone, 93.33%), CHX application exhibited a greater significant reduction than both groups (p = 0.000).

CONCLUSION

The two-visit indirect pulp therapy yielded successful results for all study groups. However, CHX would be conveniently preferable due to improving the treatment success.

CLINICAL RELEVANCE

The two-visit indirect pulp therapy applied with cavity disinfectant is a proper alternative treatment procedure in deep carious lesions, instead of conventional technique.