The antimicrobial effect of different ozone protocols applied in severe curved canals contaminated with Enterococcus faecalis: ex vivo study

Analysis of antimicrobial efficacy of sodium hypochlorite and ozonated water against biofilm in oval canals

This in vitro study compared the antimicrobial efficacy of 2.5% sodium hypochlorite (NaOCl) and 8 µg/mL ozonated water agitated by passive ultrasonic irrigation (PUI) or PUI combined with EndoActivator (EA) against mature multispecies biofilm. One hundred and five oval-shaped mandibular premolars were instrumented, sterilized, and inoculated with Enterococcus faecalis, Candida albicans, and Staphylococcus aureus, divided into: control group - saline; O3 group - ozonated water; O3 PUI group - ozonated water with PUI agitation; O3 PUI+EA group - ozonated water with PUI+EA agitation; NaOCl group - NaOCl; NaOCl PUI group - NaOCl with PUI agitation; and NaOCl PUI+EA group - NaOCl with PUI+EA agitation. Microbiological samples were collected before (S1) and after (S2) the disinfection procedures and the data were statistically analyzed using the Kruskal-Wallis test. In the culture method, there was significant disinfection in the O3 PUI+EA, NaOCl, NaOCl PUI, and NaOCl PUI+EA groups (p˂0.05). The combination of NaOCl with PUI+EA reduced microbial counts to zero (p˂0.05). In the qPCR method, there was a significant reduction in the total count of viable microorganisms in the O3 PUI, O3 PUI+EA, NaOCl, NaOCl PUI, and NaOCl PUI+EA groups (p˂0.05). It can be concluded that 2.5% NaOCl with and without agitation, as well as 8 µg/mL ozonated water with its action enhanced by the agitation techniques, were effective in root canal disinfection, and their antimicrobial efficacy is related to the microorganisms present in the biofilm.

Disinfection of caries-affected dentin using potassium titanyl phosphate laser, Rose bengal and Ozonated water on shear bond strength of deciduous teeth

AIM

To assess the efficacy of disinfection of caries-effected dentin (CAD) using KTP laser and different decontamination methods using ozonated water (OW), Rose Bengal photosensitizer (RBP), chlorhexidine (CHX), and Er, YAG laser on the shear bond strength (SBS) of adhesive resin bonded to deciduous teeth.

MATERIAL AND METHODS

A total of 50 extracted and radiographically verified carious primary molars were collected and scrutinized according to ICDAS criteria. Specimens were allocated randomly into five groups (n = 10) as per the type of CAD disinfectants. KTP laser, OW, RBP, CHX (control), and Er, YAG laser. After cavity sanitization, a resin adhesive (prime and bond NT) was smeared on the dentinal exterior followed by incremental composite filling. SBS evaluation was performed by employing specimens in the universal testing machine. The debonded surface was assessed under 40x magnification in a stereomicroscope to ascertain fracture mode. Statistical analysis was done by using the ANOVA and the Post Hoc Tukey multiple comparison tests (p < 0.05).

RESULTS

The highest SBS was exhibited by group 2 i.e., when OW was employed for CAD disinfection (10.25 ± 0.24 MPa). Whereas, the lowest SBS bond value was unveiled by samples in group 3 when RBP was applied for dentin surface sanitization (7.85 ± 0.59 MPa).CAD disinfection with KTP laser (8.25 ± 0.41 MPa), CHX (8.19 ± 0.73 MPa), and RBP displayed comparable bond values (p > 0.05).

CONCLUSION

Ozonated water and Er, YAG laser could be employed as cavity disinfectants in primary teeth as they demonstrated better shear bond strength without jeopardizing the adhesive binding capacity of restorative resins bonded to caries-affected dentin.

Preparation of Nano/Microcapsules of Ozonated Olive Oil in Hyaluronan Matrix and Analysis of Physicochemical and Microbiological (Biological) Properties of the Obtained Biocomposite

Hydrogels, based on natural polymers, such as hyaluronic acid, are gaining an increasing popularity because of their biological activity. The antibacterial effect of ozone is widely known and used, but the instability the gas causes, severely limits its application. Ozone entrapment in olive oil by its reaction with an unsaturated bond, allows for the formation of stable, therapeutically active ozone derivatives. In this study, we obtained an innovative hydrogel, based on hyaluronic acid containing micro/nanocapsules of ozonated olive oil. By combination of the biocompatible polymer with a high regenerative capacity and biologically active ingredients, we obtained a hydrogel with regenerative properties and a very weak inhibitory effect against both bacterial commensal skin microbiota and pathogenic Candida-like yeasts. We assessed the stability and rheological properties of the gel, determined the morphology of the composite, using scanning electron microscopy (SEM) and particle size by the dynamic light scattering (DLS) method. We also performed Attenuated total reflectance Fourier transform infrared (FTIR-ATR) spectroscopy. The functional properties, including the antimicrobial potential were assessed by the microbiological analysis and in vitro testing on the HaCat human keratinocyte cell line. The studies proved that the obtained emulsions were rheologically stable, exhibited an antimicrobial effect and did not show cytotoxicity in the HaCat keratinocyte model.

Disinfection of caries affected dentin using Rose Bengal, Titanium Sapphire Laser; Ammonium Hexa-fluorosilicate, and ozonated water on resin dentin bond strength

AIM

The present study intended to evaluate the shear bond strength (SBS) of resin cement bonded to caries affected dentin (CAD) after disinfection with rose Bengal (RB), Ti-Sapphire Laser, Ammonium Hexafluorosilicate (NH₄)₂[SiF₆], and ozonated water (O₃) MATERIAL AND METHODS: A total of 100 extracted human mandibular molars were acquired using caries severity code, 6 of the ICDAS criteria. To achieve homogeneity and prevent size-biased distributions, the average cavity preparation of all specimens had a depth of 2 mm and a breadth of 3 mm. Specimens were divided into five groups (n = 20) at random according to type of disinfection. Group 1: control group, Group 2: RB, Group 3: O₃, Group 4: Ti-sapphire laser, and Group 5: (NH4)2[SiF₆]. All specimens were etch and rinsed, bonding agent was applied and restored with resin cement. Estimation of SBS was performed by placing samples (10/group) in universal testing machine. Stereomicroscope under 40 × magnification was employed for failure mode analysis (FMA). Statistical analysis was executed using the ANOVA and the Tukey multiple test (p<0.05).

RESULTS

The highest SBS was demonstrated in the control group when CAD bonded to resin cement without disinfection (18.22±1.14 MPa). Likewise, the lowest SBS values were unveiled by CAD disinfection with O₃ (12.44±1.36 MPa). Similarly, CAD when disinfected with RB (16.25±1.01 MPa) and Ti-sapphire laser (16.25±1.22 MPa) bonded to resin cement exhibited comparable bond results (p>0.05).

CONCLUSION

Caries affected dentin when treated with etch and rinse technique without the use of disinfectant displayed the highest SBS. However, it was seen that utilization of various disinfectants has altered the adhesion capacity or bonding efficacy of caries-affected dentin.