The efficacy of gaseous ozone on some cariogenic bacteria.

The aim of this study is to analyze ozone impact on some cariogenic bacteria in ex vivo and in vitro conditions. The in vitro part of study inoculated dentine with strains of Streptococcus mutans ATCC 33402 and Lactobacillus paracasei ATCC 11974 bacteria. Samples of dentine before and after 40s ozone treatment were collected and anaerobically incubated. Samples of cariogenic dentine (N = 24) were collected from permanent molars within the ex vivo segment of the study, prior and after 40s ozone treatment and a number of colonies were counted after incubation. For the in vitro part of study, results have shown a statistically significant average value of reduction of Streptococcus mutans ATCC 33402 and Lactobacillus paracasei ATCC 11974 prior and after ozone treatment (p < 0.001). The ex vivo segment of the study has also demonstrated a statistically significant difference in the number of bacteria prior and after ozone implementation (p < 0.001). Gaseous ozone demonstrated a strong antimicrobial effect on cariogenic bacteria in both in vitro and ex vivo conditions and it can be used as an adjuvant in caries therapy.

Radiopacity of composite dental materials using a digital X-ray system.

The aim of this study was to evaluate the radiopacity of 32 current dental composite materials with digital technique. Digital radiographs with CCD sensor along with an aluminum step wedge, 1-mm-thick tooth slice and 1mm thick composite specimen were taken in five different combinations of exposition/voltage. The radiopacity in pixels was determined using Digora 2.6. software. The equivalent in thickness of aluminum for each material was then calculated from the calibration curve. 74.9% of all tested materials in all exposure combinations had radiopacity between 2 mm and 4 mm aluminum equivalent. The radiopacity of composites ranged from 0.61 mm Al (Gradia Direct Anterior) to 4.78 mm Al (Te-Econom). The average radiopacity for enamel and dentine was 2.05 and 1.11 mm Al. The use of digital technique for radiopacity is an easy, reliable, fast and precise way to analyze different dental materials. Most of the tested composite materials fulfill the requested criteria for radiopacity with a few exceptions.

Caries prevalence among schoolchildren in Zagreb, Croatia.

AIM: To investigate the prevalence of dental caries and treatment needs in schoolchildren aged 7-14 years from Zagreb. METHODS: Dental examinations based on the World Health Organization criteria were performed on 1168 children in the period 2009-2010. The teeth were clinically examined with standard dental instruments using visual-tactile method under standard dental light. We recorded the clinical indexes of decayed, missed, and filled teeth (DMFT and dmft; upper-case letters refer to permanent and lower-case letters to primary teeth) and decayed, missed, and filled surfaces (DMFS), as well as the significant caries index (SiC). RESULTS: The median DMFT and DMFS of all children were 3 and 4, respectively. The median DMFT and DMFS of 12-year-old children were 4 and 5, respectively. The highest median DMFT score of 7 was found among 14-year-old children. There was a significant difference between age groups (7-10 years and 11-14 years) in DMFT and DMFS. Among 8-year-old children, the median dmft index was the highest (5.5) and SiC index was 7.4. As far as the location of caries on the surface of the first permanent molar is concerned, caries occurred mostly in the central occlusal surface (27.6%). CONCLUSION: Our results showed a high caries prevalence among schoolchildren in Zagreb, indicating a need for an extensive program of primary oral health care.

Clinical evaluation of indirect composite restorations at baseline and 36 months after placement.

This study determined the differences in clinical performance between materials for indirect composite restorations based on Ormocer (Admira) and nano-hybrid resin composite (Grandio), both at baseline and 36 months after placement. Modified USPHS criteria were used to analyze the degree of quality. Marginal integrity was assessed 36 months after placement, whereupon, the restorations fabricated from Grandio achieved an Alpha 1 score of 70.7% and an Alpha 2 score of 29.3%. The Wilcoxon test revealed a statistically significant difference in the evaluation of marginal integrity (p = 0.003), anatomic form of the marginal step (p = 0.025) and discoloration of the margins (p = 0.014) at baseline and after 36 months. For Admira, the Wilcoxon test showed statistically significant differences in the evaluation of surface texture (p = 0.025), anatomic form of the complete surface (p = 0.034), anatomic form of the marginal step (p = 0.008), marginal integrity (p = 0.002) and discoloration of the margins (p = 0.008) at baseline and after 36 months. According to the number of restorations awarded the Alpha 1 score (excellent), the overall success rates for marginal integrity were 70.7% for Grandio and 71.8% for Admira; both were evaluated 36 months after placement. The results have shown that the indirect restorations were acceptable after 36 months, which indicates a 100% success rate. Over 36 months, no statistically significant differences were noted between the two materials. Indirect resin composite restorations represent a good therapy choice for severely damaged teeth.