Treatment effect of ozone and fluoride varnish application on occlusal caries in primary molars: a 12-month study

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 Treatment for the Management of Caries in Primary Dentition: A Systematic Review of Clinical Studies

Dental caries in children is a frequent and debilitating condition, whose management is often challenging. The aim of this systematic review was to investigate the effectiveness of ozone applications for the treatment of caries in primary dentition. According to PRISMA guidelines, a systematic literature search was performed up to 6 January 2024. Clinical studies using ozone to treat caries of deciduous teeth were considered for inclusion. Out of the 215 records retrieved, seven studies were eventually included in the review, all of which used gaseous ozone. Four studies were judged at high risk of bias, two at low risk, and one of some concerns. The great heterogeneity of designs, outcomes, and protocols made it impossible to conduct a meta-analysis. Despite some limitations, the evidence yielded by the included studies suggests that ozone application, regardless of the protocol applied, is comparable to other interventions in terms of clinical outcomes and anti-bacterial activity, with no reported adverse effects and good patient acceptance. Therefore, ozone application may be a non-invasive approach to treat caries in primary dentition, especially in very young and poorly cooperative patients. Further standardized and rigorous studies are, however, needed to identify the best clinical protocols for this specific field.

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.

Ozone Therapy for Early Childhood Caries (ECC) Treatment: An In Vivo Prospective Study

The present study aimed to evaluate the effectiveness of ozone therapy in (1) increasing the compactness of decayed dentin (main aim), (2) reducing dentin hypersensitivity, (3) decreasing the salivary bacterial count, and (4) improving the quality of life in ECC-affected children during a 3-month follow-up. A total of 20 subjects uncooperative with conventional restorative treatment were treated with a 60 s ozone application/week (OzoneDTA®) for 4 weeks. Patients were evaluated at T0 = baseline; T1 = after ozone cycle and T2, T3, T4 = 1, 2, 3-month follow-up, respectively. Dentin compactness was evaluated according to the Affected Dentine Scale (ADS) proposed by the authors; dentin hypersensitivity was recorded with the Wong–Baker Faces Pain Rating Scale (WBFPRS); salivary bacteria were measured with the Saliva Check Mutans Test and quality of life with the Early Childhood Oral Health Impact Scale (ECOHIS). ADS values and salivary bacteria count results were analyzed using non-parametric tests. Statistically significant differences were detected for both parameters between T0 and T1 (p < 0.01). At T1, dentin hypersensitivity was resolved and quality of life improved. Ozone therapy is a simple and painless approach, which might be useful for controlling caries’ progression in uncooperative children until appropriate cooperation is achieved.

Nonrestorative treatment of initial caries lesion in primary teeth: a systematic review and network meta-analysis

OBJECTIVE

To identify the best available approach to avoid initial caries lesions progression in primary teeth.

MATERIALS AND METHODS

Search was performed in MEDLINE/Pubmed, Web of Science, Embase and CENTRAL databases until March 2021. Studies compared treatment options to avoid the initial caries lesion progression with at least 12 months of follow-up were included. Network meta-analyses were conducted considering the non-progression of caries lesions as an outcome.

RESULTS

Potentially eligible studies were screened (n = 2820) and eleven were included. Six studies evaluated the use of fluoride varnish, resin infiltration, sealing, and toothbrushing/flossing on proximal initial caries lesions. When considering occlusal surfaces, only two studies evaluating the ozone gas, fluoride varnish, resin infiltration, and sealants were included. For buccal/lingual surfaces, three studies evaluating toothbrushing, CPP-ACP paste, fluoride varnish, and resin infiltration were included. For all types of surfaces, the resin infiltration showed the best probability to avoid the progression of initial caries lesions.

CONCLUSION

The limited number of included studies, most with a high risk of bias and lack of hard outcomes, such as frank cavitation, makes it not feasible to recommend a specific management approach for initial caries lesion control in primary teeth with a high certainty of evidence. PROSPERO: #CRD42016037781.

Micromolar sodium fluoride promotes osteo/odontogenic differentiation in dental pulp stem cells by inhibiting PI3K/AKT pathway

OBJECTIVE

Sodium fluoride (NaF) plays an important role in preventing dental caries. However, the regulatory effect of NaF on the committed differentiation of DPSCs is not fully understood. In this study, we characterized the impact of micromolar levels of NaF on the osteo/odontogenic differentiation of DPSCs.

DESIGN

DPSCs were isolated from healthy human third molars and were cultured in conditioned media with different concentrations of NaF. RNA sequencing (RNA-seq) combined with Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis was used to assess the pathways regulated by NaF. Alkaline phosphatase activity, Alizarin red staining, Western blotting, and real-time qRT-PCR were used to determine the osteo/odontogenic differentiation in DPSCs treated with NaF.

RESULTS

NaF significantly promoted the osteo/odontogenic differentiation of DPSCs at micromolar levels. Furthermore, RNA-seq and KEGG pathway enrichment analysis indicated that the PI3K/AKT pathway was involved in the pro-osteoclastogenesis effect of NaF. Western blotting analysis exhibited that the phosphorylation of AKT was decreased in NaF-treated DPSCs. Chemical inhibition of the PI3K/AKT pathway abrogated the NaF-promoted DPSCs osteo/odontogenic differentiation.

CONCLUSION

Micromolar NaF can promote the osteo/odontogenic differentiation of DPSCs by inhibiting the PI3K/AKT pathway.

DATA AVAILABILITY

The data used to support the findings of this study are available from the corresponding author upon request.

Diagnosis and Management Approaches for Non-cavitated Carious Dental Lesions- A Narrative Review

Background:

Dental caries is one of the most prevalent diseases. Its detection and management should start with a comprehensive treatment plan, with the goals of the elimination of cariogenic bacteria, the reduction of plaque acidogenicity, the encouragement of tooth remineralization, and the repair of damaged teeth.

Objectives:

The aim of this paper was to review the literature regarding the latest updates on the diagnosis and management approaches of non-cavitated carious dental lesions.

Methods:

Studies regarding the diagnosis and management of non-cavitated carious dental lesions were included.

Results:

The subclinical non-cavitated carious lesion might progress to an early enamel lesion, develop into an established dentin lesion, or sometimes end up with a lesion reaching the pulp. The detection and management of caries should be patient-centered, risk-based, and evidence-supported, and should consider the dentists’ expertise and the patients’ needs and preferences. The visual-tactile and radiographic detection of non-cavitated carious lesions are greatly helped by the advances of non-invasive detection tools such as DIAGNOdent, fiber-optic transillumination, quantitative light-induced fluorescence, and DIAGNOcam.

Conclusion:

Accordingly, non-cavitated carious lesions can be arrested by several non-invasive techniques, which are preferred over the invasive options. The clinicians can use sealants plus fluoride varnish on occlusal surfaces, fluoride varnish or resin infiltration on proximal surfaces, and resin infiltration,fluoride gel, or varnish alone on facial or lingual surfaces to manage non-cavitated carious lesions.

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.

Efficacy of CO lasers in preventing dental caries in partially erupted first permanent molars: a randomized 18-month clinical trial

The aim of this controlled randomized double-blinded clinical trial was to evaluate the use of a CO₂ laser with or without topical application of acidulated fluorides in the prevention of dental caries in partially erupted first permanent molars. We selected 61 healthy children at high risk of caries, all between 6 and 8 (7.1 ± 0.8) years of age and with 4 partially erupted first permanent molars. A CO₂ laser device emitting at 10.6 μm was used (0.5 W, 0.05 mJ per pulse, 10 kHz). Each first molar in an individual was randomly assigned to one treatment: (L) CO₂ laser (0.066 J/cm²); (FL) 1.23% acidulated fluoride gel and CO₂ laser (0.066 J/cm²); (V) 5% fluoride varnish, or (S) sealant (control). Patients were followed-up at 3, 6, 12, and 18 months after treatment, through direct visual examination and by an operator blinded to the treatments (kappa ≥ 0.70). The International Caries Detection and Assessment System (ICDAS-II) index was used to assess the soundness of tooth structure or the presence of white spot lesions, cavitated enamel, and/or dentin lesions. The Yildiz Visual Index was used to evaluate sealant retention. Results were evaluated using Kaplan-Meier survival analysis, and the hazard ratio of the treatments was estimated using shared frailty models with a gamma distribution, which considered the patient as a cluster. There were no significant differences among treatments compared to sealants. After 18 months, the use of a CO₂ laser with or without acidulated fluorides was shown to be effective in preventing caries on the occlusal surface of partially erupted permanent first molars in children at high risk for caries.

Sodium fluoride regulates the osteo/odontogenic differentiation of stem cells from apical papilla by modulating autophagy

Fluoride (sodium fluoride) is thought to be essential in the development of tooth, and research shows that fluoride can modulate the differentiation of dental stem cells. However, the effects of fluoride on the committed differentiation of stem cells from apical papilla (SCAPs) and the underlying mechanisms remain unclear. Here, SCAPs were isolated from healthy extracted human third molars with immature roots and then were cultured with NaF conditioned media. Cell Counting Kit-8, EdU staining, and flow cytometry were performed to detected the proliferation activity. Alkaline phosphatase (ALP) activity, Alizarin Red staining, Western blot assay, and real-time reverse-transcription polymerase chain reaction were applied to assess the osteo/odontogenic differentiation NaF-treated SCAPs. Western blot assay and transmission electron microscope were used to evaluate the autophagy involved in the differentiation of SCAPs. ALP activity, ALP protein, and messenger RNA (mRNA) expression showed that 0.5 mM was the optimal concentration for the induction of SCAPs by NaF. 0.5 mM NaF-treated SCAPs induced more mineralized nodules as compared with untreated cells. Moreover, the osteo/odontogenic markers (RUNX2, OSX, DSP, and OCN) in mRNA levels were upregulated while the protein levels of these markers increased considerably in 0.5 mM NaF-treated SCAPs. Furthermore, the autophagy-related proteins (LC3, ATG5, and Beclin1) increased in NaF-treated SCAPs, and the osteo/odontogenic makers significantly decreased while silencing ATG5 to block autophagy. In all, sodium fluoride can regulate the osteo/odontogenic differentiation of SCAPs by modulating autophagy.

Sources of free radicals and oxidative stress in the oral cavity

OBJECTIVE

An oral cavity is a place especially susceptible to oxidative damage. It is subjected to many environmental pro-oxidative factors or factors that have the ability to generate reactive oxygen species (ROS). The aim of this article is to present the main sources of ROS and oxidative stress in the oral environment.

DESIGN

A literature search was performed using the PubMed and Google Scholar databases.

RESULTS

One of the most important ROS sources in the oral cavity is periodontal inflammation. Other sources of ROS include: xenobiotics (ethanol, cigarette smoke, drugs), food (high-fat diet, high-protein diet, acrolein), dental treatment (ozone, ultrasound, non-thermal plasma, laser light, ultraviolet light), and dental materials (fluorides, dental composites, fixed orthodontic appliances, and titanium fixations). It has been shown that excessive production of ROS in the oral cavity may cause oxidative stress and oxidative damage to cellular DNA, lipids, and proteins, thus predisposing to many oral and systemic diseases.

CONCLUSIONS

Recognition of the exogenous sources of ROS and limitation of exposure to the ROS generating factors can be one of the prophylactic measures preventing oral and systemic diseases. It is suggested that antioxidant supplementation may be helpful in people exposed to excessive production of ROS in the oral cavity system.