Evaluation of oral streptococci in saliva of children with severe Early Childhood Caries and caries-free.

AIM: Oral streptococci were found to be associated with Early Childhood Caries. The aim of this study was to evaluate the 6 different bacteria in the streptococcus group in the saliva of children with severe early childhood caries (S-ECC) by polymerase chain reaction (PCR). MATERIALS AND METHODS: A total of 60 children between 3 and 6 years of age were divided into two groups: children with S-ECC (Group S-ECC; n=30) and children who were caries-free (Group CF; n=30), according to the dmft and dmfs indices. Unstimulated saliva was collected from all participants for the detection of streptococcal group bacteria, including: Streptococcus mutans, Streptococcus oralis, Streptococcus sanguinis, Streptococcus gordonii, Streptococcus salivarius, and Streptococcus sobrinus, using PCR-restriction fragment length polymorphism (RFLP) of amplified 16S rRNA gene. The data were analysed using SPSS software. RESULTS: The prevalence of S. oralis was significantly higher in the S-ECC group compared to the CF group (p<0.05). However, the frequencies of S. mutans, S. sanguinis, S. gordonii, S. salivarius, and S. sobrinus were similar between the two groups (p>0.05). The amount of streptococci colonies was higher in the S-ECC group compared to the CF group (p<0.05). CONCLUSION: S. mutans or S. sobrinus alone may not be the only indicators for high risk of caries, but the prevalence of S. oralis in saliva may be a risk factor for increased caries activity in S-ECC.

Effects of first permanent molar extraction on space changes observed in the dental arch using data mining method.

AIM: The high incidence of caries in first permanent molars (FPMs) makes premature extraction of these teeth common. The extraction of the permanent teeth results in various changes in the dental arch. The aim of this study was to evaluate space closure, the eruption of second permanent molars (SPMs), and changes in dental arch after extraction of the FPMs. MATERIALS AND METHODS: Eruption of 83 SPMs was recorded and radiographically developmental stage of these SPMs in the pre-extraction panoramic radiograph was assessed. Space was measured between the distal surface of the second premolar and the mesial surface of SPM. RESULTS: Out of 55 patients, 28 (50.9%) were males and 27 (49.1%) were females. Thirty-seven (44.6%) of 83 teeth belonged to category 1, 17 (20.5%) teeth belonged to category 2, and 5 (6.02%) teeth belonged to category 3. Although category 4 was not found, 24 (28.9%) teeth were observed to be in category 5. Out of all SPMs, 10.8% represented the ''ideal'' stage of Demirjian's dental development, stage E. CONCLUSION: In patients who had the FPMs extracted before the eruption of the SPM, it is important with regards to the patients' comfort and health to review the patient regularly and to determine any need for orthodontic treatment.

In vitro investigation of antimicrobial effects, nanohardness, and cytotoxicity of different glass ionomer restorative materials in dentistry.

AIMS: The aim of this in vitro study was to investigate the antimicrobial effects, nanohardness, and cytotoxicity of different glass-ionomer restorative materials in dentistry. MATERIALS AND METHODS: The following glass-ionomer restorative materials were used in our study: Argion (VOCO, Germany), Zirconomer (Shofu Inc., Japan), EQUIA Forte (GC, Japan), Fuji II LC capsule (GC, Japan), and Fuji IX GP capsule (GC, Japan). For the cytotoxicity test, a cell culture without release liquids was used as the control group. Microdilution and a disk diffusion test were used to measure the antimicrobial activity. The MTT (3- [4,5-dimethylthiazol-2-yl] -2,5-diphenyltetrazolium bromide) assay was used to evaluate cytotoxicity. Nanohardness was measured using a nanoindenter device. RESULTS: Our study determined that all restorative materials used in this study inhibited bacterial growth in cultures containing 1 × 102 cfu/ml of the bacterial concentrations (Lactobacillus casei and Streptococcus mutans) and that all restorative materials inhibited fungal growth in the cultures containing <1 × 102 cfu/ml of the fungal strains (Candida albicans). IC50 values obtained for the cytotoxicity test were analyzed using the Chi-square test. After a 72-h incubation period, Zirconomer, EQUIA Forte, Fuji IX GP capsule, and Fuji II LG capsule showed statistically significant lower cell viability values. (P < 0.05). The Kruskal-Wallis analysis was performed on the values obtained from the nanohardness test; the differences between the groups were found to be significant (P < 0.05). CONCLUSIONS: All materials tested showed low antimicrobial activity, and the antifungal activity of these materials was found to be lower than their antimicrobial activity. Only Argion showed non-cytotoxic effect. Beginning with the group with the highest nanohardness values and ending with the lowest, the groups are ranked in the following order: Fuji II LC capsule, EQUIA Forte, Argion, Fuji IX GP capsule, and Zirconomer.

Leakage testing for different adhesive systems and composites to permanent teeth.

AIM: To explore the microleakage of different adhesive systems and flowable composites to permanent teeth. SUBJECTS AND METHODS: In this study, a total of 84 human premolar teeth were used. Class V cavities were prepared on the buccal surfaces. The teeth were randomly assigned to six groups of 14 teeth each as follows: The first group - etch-rinse adhesive applied and cavities filled with flowable composite, the second group - etch-rinse adhesive applied and cavities filled with bulk-fill resin composite, the third group - one-stage self-etch (SE) adhesive applied and cavities filled with flowable composite, the fourth group - one-stage SE adhesive applied and cavities filled with bulk-fill resin composite, the fifth group - two-stage SE adhesive applied and cavities filled with flowable composite, and the sixth group - two-stage SE adhesive applied and cavities filled with bulk-fill resin composite. All specimens were then stored for 24 h at 37°C in distilled water. Teeth were then thermocycled for 500 cycles between 5°C and 55°C prior to immersion in 0.5% basic fuchsin for 24 h. Two mesiodistal cuts of each tooth were photographed for leakage with a digital camera. The dye infiltrated surface for each specimen was measured and data were collected with a software program. Statistical evaluations were done by nonparametric Kruskal-Wallis test and Mann-Whitney U-test. RESULTS: There were statistically significant differences in mean microleakage ratio among the groups (P < 0.05). The first group had shown significantly increased microleakage areas than the other four groups (third, fourth, fifth, and sixth groups) (P < 0.05), except for the second group (P > 0.05). It was also no significant different between the mean microleakage areas of group fourth and group fifth (P > 0.05). The sixth group had exhibited the lowest microleakage areas, and it was statistically significant (P < 0.05) compared to the other groups. CONCLUSION: In this study, it has been found that the use of total etch adhesive systems resulted in high leakage values.