Influence of Ozone Application in Stepwise Excavation Procedure of Primary Molars With Deep Carious Lesion
Condition: Deep Caries; Ozone
MeSH terms: Dental Caries
Study type: Interventional

Summary: 
      Purpose: The purpose of this study was to investigate the clinical and microbiological
      effectiveness of the ozone application in stepwise excavation of primary molars.

      Methods: This study was conducted in vivo conditions with 105 lower primary second molars
      that had deep caries lesions with the risk of pulpal exposure. The teeth were randomly
      divided into three groups: Conventional stepwise excavation without any disinfectant, 2%
      chlorhexidine digluconate(CHX) and ozone application. In four different stages (after;
      initial excavation, ozone/CHX application, four months, final excavation), dentine samples
      were collected for microbiological analysis of mutans streptococci, lactobacilli and total
      number of colony forming units. Clinical changes as dentine colour, humidity, consistency
      were recorded. The data were analysed by Mann-Whitney U, Friedman and chi-square test.
    

Detailed description: 
      Informed consent including possible risks, discomforts and benefits about the procedure were
      obtained from all parents of the young patients.

      The required sample size for this study was 35 in each subgroup (82 percent power, two-sided
      five percent significance level) for the detection of a significant difference. This study
      was conducted on 105 patients aged 6 to 10 years (59 girls, 46 boys) who attended the
      Pediatric Dentistry Department. None of the patients included in the study were medically
      compromised. Each patient had one mandibular second primary molar with deep carious lesion
      and pulp perforation risk. All teeth with deep carious lesions were examined clinically and
      radiographically.

      The following inclusion criteria were used;

        -  Active carious lesion in deep dentine of primary second molars,

        -  Absence of clinical symptoms of irreversible pulpitis such as spontaneous pain or
           longtime pain against thermal and chemical stimuli,

        -  Absence of sensitivity to percussion or palpation, pathological mobility, swelling or
           fistula any discoloration except for carious lesion.

        -  Absence of any interradicular lesions, periapical radiolucency, pathological resorptions
           and pulpal calcifications.

      A randomized, controlled, clinical trial was designed in a sample of 105 primary molars (35
      teeth in each group) as three treatment groups: Step-wise excavation without any disinfectant
      (control group), step-wise excavation with CHX application (positive control group), and
      step-wise excavation with gaseous ozone application (experimental group).

      All procedures were performed by one investigator. After mandibular anesthesia of the tooth,
      rubber dam isolation was provided. Carious enamel, lateral walls of the cavity and necrotic
      dentin was removed with carbide burs. Removal of carious dentin was performed with dentin
      excavators and low speed-burs, and left some caries at the central part. It was decided to
      leave potentially mineralizable affected dentin by hand sensitivity. Following the same
      procedures, the teeth were randomly divided into 3 groups (n=35):

      Control Group: After partial removal of carious dentin, calcium hydroxide [Ca(OH)2] base
      material (Dycal; Dentsply International Milford, USA) was placed on the remaining carious
      dentin without applying any cavity disinfectants.

      Positive Control Group: After partial removal of carious dentin, 2% CHX solution (Cavity
      Cleanser, Bisco, USA) was applied to the cavity for 60 s with an applicator brush for
      disinfection procedure. According to the manufacturer instructions, puddled solution was
      removed with a new brush without dry to leave site moist. Then, Ca(OH)2 base (Dycal;
      Dentsply) was placed on the remaining carious dentin.

      Experimental Group: After partial removal of carious dentin, ozone gas (Heal ozone, KaVo
      Dental, Germany) with the concentration of 2100 ppm was applied to the cavity for 60 s for
      disinfection procedure. Ozone production stopped if the airtight seal over the tooth was
      broken during treatment, therefore, silicon caps were selected according to the size of each
      tooth. And Ca(OH)2 base was placed on the remaining carious dentin.

      All the teeth were then temporarily sealed with glass ionomer cement and coating agent. After
      4 months, radiographic and clinical examinations were repeated. Following rubber dam
      isolation and anesthesia, temporary fillings were removed. Removing of Ca(OH)2 on the
      remaining carious dentin was carefully performed with excavators. Subsequent to this
      procedure, remaining demineralized dentin was completely removed in all groups. Floor of the
      cavity was then covered with Ca(OH)2 base material (Dycal; Dentsply/Caulk) and glass ionomer
      lining. The cavities were then restored with composite resin after the 2-stages self-etch
      bond application.

      Microbiological analysis:

      During these procedures dentin samples were collected with a sterile carbide bur #14 from
      each group for microbiological analyses.

      Clinical photograph was taken with dental explorers pointing to ensure that all samples were
      collected from the same site in all following stages. The dentine samples were collected
      enough to fill the slots of a sterile No.14 round carbide bur and the respective samples were
      placed into 1 ml thiogluconate medium then transported to the microbiology laboratory in 2
      hours to be analyzed for the mutans streptococci, lactobacilli and the total number of colony
      forming units (CFU).

      The samples were homogenized on a vortex mixer for 15 seconds under laboratory conditions.
      Mitis Salivarius agar as the selective medium for Streptococcus mutans, rogosa agar for
      Lactobacilli and Brain Hearth agar supplemented 5% blood for the total number of CFU were
      used. Tenfold dilution were plated onto agars and incubated anaerobically for 48 hours and
      the colonies were counted on the convenient dilution.

      Clinical Evaluation For the clinical analysis, the colour, consistency and humidity of the
      dentine were also recorded during taking microbiological samples.

      Color findings classifications were recorded according to following criteria: Light yellow,
      yellow, light brown, dark brown, black. Classification of dentin consistency was determined
      by probing and criteria were "very soft", " "soft", "moderate hard" and "hard". Dentin
      humidity was recorded as "wet" and "dry". Accordingly, the dentine was probed and if moisture
      leakage occurred, it was classified as wet or if it did not then it would be classified as
      dry.
    

Intervention name(s): ozone; chlorhexidine digluconate; Control
Intervention type(s): Other; Other; Other
Intervention description(s): In the two-visit indirect pulp therapy, due to reduce the number of bacteria remaining in the cavity, the antimicrobial agents can be used as cavity disinfectants such as ozone.; In the two-visit indirect pulp therapy, due to reduce the number of bacteria remaining in the cavity, the antimicrobial agents can be used as cavity disinfectants such as chlorhexidine digluconate.; without any cavity disinfectant
Intervention MeSH terms: Chlorhexidine; Chlorhexidine gluconate
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: randomized, three-arm parallel, two-blinded clinical trial
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment
Keywords: ozone; Deep Carious Lesion; Primary Molars