Clinical antibacterial effectiveness and biocompatibility of gaseous
ozone after incomplete caries removal
Received: 19 November 2017 /Accepted: 24 May 2018
Springer-Verlag GmbH Germany, part of Springer Nature 2018
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)andLactobacillus spp. (p < 0.001), similarly to chlor-
hexidine. 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% chlor-
hexidine. 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.
Incomplete caries removal
In contrast to traditional treatment of dentinal carious lesions,
which include complete removal of carious tissue, there is an
increasing interest into less invasive techniques with incom-
plete caries removal. The biological rationale for this preser-
vative approaches is that cariogenic bacteria die or remain
dormant when isolated from nutrition by sufficient seal, and
therefore, caries arrest and carious dentin remineralizes.
Incomplete caries removal, performed in one or two steps,
seems advantageous for the treatment of deep carious lesions.
Namely, growing number of clinical studies showed that in-
complete excavation reduces the risk of pulpal exposure com-
pared with complete caries removal [1, 2]. However, most of
currently available direct restorative materials cannot provide
adequate seal and prevent leakage for a sufficient long period
of time. Therefore, residual bacteria may proliferate in the
smear layer and dentinal tubules of the cavity causing pulp
irritation, secondary caries, and restoration failure over time
[3, 4]. For solving this issue, there are recommendations to use
* Jelena Krunić
Department of Dental Pathology, Faculty of Medicine, University of
East Sarajevo, Studentska 5, 73300 Foca, Bosnia and Herzegovina
Department of Pharmacology in Dentistry, School of Dental
Medicine, University of Belgrade, Belgrade, Serbia
Department of Human Genetics, School of Dental Medicine,
University of Belgrade, Belgrade, Serbia
Department of Oral Rehabilitation, Faculty of Medicine, University
of East Sarajevo, Foca, Bosnia and Herzegovina
Clinical Oral Investigations