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The aim was to evaluate the effect of a 2.5% titanium tetrafluoride (TiF4) solution followed by self-etching adhesives against Streptococcus mutans/Sm and Lactobacillus casei/Lc. Four cylindrical-shaped cavities were performed on each dentin surface of 40 third molars and contaminated with Sm or Lc. Each one of the four cavities received one of the following treatments (n = 10): 1) control; 2) TiF4; 3) Clearfil SE Bond/CSE or Adper EasyOne/AEO; 4) TiF4 followed by CSE or AED. ANOVA was applied to data. The TiF4 solution showed an antimicrobial effect, although the TiF4 used for dentin pretreatment before CSE or AEO showed no influence on antimicrobial effect.

The aim of this in vitro study was to evaluate the calcium and phosphorus concentrations in enamel surfaces before, during, and after treatment with in-office 35% hydrogen peroxide bleaching agents with 2% calcium gluconate (WCa) or without calcium gluconate (W). Twenty sound human third molars were divided into 2 groups of 10. The bleaching agents were applied to the tooth surfaces in accordance with the manufacturer's instructions: WCa, 40 minutes per day at 3 sessions with 7-day intervals; W, 3 × 15 minutes per day at 3 sessions with 7-day intervals. Enamel microbiopsies were performed prior to the bleaching treatment, immediately after each bleaching session (first, second, and third applications), and 7 and 14 days following the last bleaching treatment. The concentration levels of calcium and phosphorus in the microbiopsy specimens were recorded spectrophotometrically. There was a statistically significant decrease in the calcium concentration 7 days after the last bleaching treatment, but there was a recovery to baseline values at 14 days, regardless of the bleaching agent used (WCa and W). When W was used, there was no difference in the phosphorus concentration over time. The phosphorus concentration in the WCa group decreased after the third application, showing a significant difference from the W group at this time. However, an increase in the phosphorus concentration was observed in the posttreatment period, and no significant differences were observed between values at baseline and those at 14 days posttreatment. The in-office bleaching gel containing 2% calcium gluconate did not affect the calcium and phosphorus concentrations in enamel as compared to a calcium-free bleaching agent.

Chemomechanical caries removal, when compared with removal using conventional rotary instruments, seems to preserve healthy tooth structure with less trauma to the patient. This study performed in vivo analysis of the total number of microorganisms in dentin after the use of conventional or chemomechanical (papain gel) caries removal methods. Analyses were performed before caries removal (baseline), immediately after caries removal, and 45 days after caries removal and temporary cavity sealing. Sixty patients were selected for this study, each with two mandibular molars (one on each side) with occlusal caries of moderate depth, for a total of 120 teeth. For each patient, the carious lesion of one tooth was removed by conventional methods using low speed drills (Group 1). For the other tooth, a chemomechanical method was used (Group 2). Dentin samples were collected at the three intervals and subjected to microbiological culture in blood agar. For the total number of microorganisms in both groups, ANOVA and Tukey tests (which considered the baseline values as a covariable) showed a higher microbial count immediately after the preparation of the cavity compared to the count at 45 days (P < 0.05). For both groups, the total count of microorganisms in dentin decreased 45 days after placing the temporary cavity sealing.

Aim: The aim of this in vitro study was to evaluate the influence of time after treatment with a 35% hydrogen peroxide bleaching agent on the shear bond strength between composite resin and sound enamel and dentin., Methods and Materials: Eighty dental slabs - 40 enamel (E) slabs and 40 dentin (D) slabs - were embedded, flatted, and divided into four groups (n=10). In G1 the E and D slabs were kept in artificial saliva for 14 days. For the G2, G3, and G4 groups the E and D slabs were submitted to bleaching treatment with a 35% hydrogen peroxide bleaching agent. At different times after bleaching treatments (G2=immediate; G3=seven days; G4= fourteen days), composite resin cylinders were made using an adhesive system. Tests were performed in a universal testing machine at a speed of 0.5 mm/min to obtain the values in MPa., Results: For enamel, the Kruskal-Wallis test and Dunn Method showed G1 differed significantly from G2 (G1=13.40 a; G2=6.64 b; G3=16.76 a; G4=11.64 ab). For dentin, the analysis of variance (ANOVA) and Tukey tests showed that G1 differed significantly from G2 and G3 (G1=12.11 a; G2=4.97 b; G3=8.67 c; G4=11.86 ac)., Conclusion: It is recommended adhesive restorative procedures in enamel be delayed for seven days post-bleaching treatment with 35% hydrogen peroxide, while restorations in dentin should be delayed for 14 days following bleaching treatment.

This study sought to determine the antimicrobial susceptibility of Staphylcoccus aureus and viridans group streptococci strains collected from the forearm skin and saliva of 30 patients at high risk of endocarditis. Agar susceptibility tests of antibiotics routinely utilized in dentistry were used to verify antimicrobial resistance of bacterial strains. Of the Staphylcoccus aureus strains, 50% were resistant to ampicillin, 53.3% to amoxicillin, 60.0% to penicillin G, 13.3% to amoxicillin/clavulanate, 20.0% to azithromycin, 27.6% to clarithromycin, 23.3% to erythromycin, 3.3% to cefazolin, and 6.7% to clindamycin. Regarding streptococci, 16.7% of the strains were resistant to ampicillin, 16.7% to amoxicillin, 23.3% to azithromycin, 23.3% to clarithromycin, 30.0% to erythromycin, 13.3% to cefazolin, 26.7% to clindamycin, 16.7% to penicillin G, and 3.3% to amoxicillin/clavulanate. Pathogens associated with bacterial endocarditis exhibited elevated resistance rates against the antibiotics used for prophylaxis in dentistry.

The aim of this study was to detect and monitor the acquisition of mutans streptococci (MS) in healthy Brazilian children. Samples of 4 different sites (saliva, tongue dorsum, dental ridges, and dental plaque, if teeth were present) were collected from 33 edentulous nursery school infants (5.9+/-1.5 month-old), using sterilized swabs, bi-monthly for 24 months. Saliva samples from the mothers were collected only once. After inoculation, and incubation typical morphotype colonies, were isolated and submitted to amplification by the technique of polymerase chain reaction (PCR) for identification. The PCR method identified 1667 strains as MS In 29 of the children's samples, the first positive culture for MS occurred at 15.3+/-4.6 months. At the end of the follow-up period, 77% of the children were classified as colonized and in 33% MS was found as a transient microorganism. A positive correlation was found between the time of MS acquisition by the infant and the number of erupted teeth (p<0.0001), and the time of emergence of the first tooth (p=0.0048). After 24 months, there were no dental caries, and 77% of children remained caries-free. These results indicate that MS colonization in this sample of low-income pre-school children may begin earlier than suggested by some investigations.