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Antibacterial Activity of Propolis versus Conventional Endodontic Disinfectants against Enterococcus faecalis in Infected Dentinal Tubules

INTRODUCTION The antibacterial activity against Enterococcus faecalis of 2 propolis samples was investigated in a dentin block model, and their effectiveness was compared with that of established endodontic disinfectants, chlorhexidine (CHX) and calcium hydroxide [Ca(OH)(2)]. METHODS Standardized dentin blocks were infected with E. faecalis ATCC 29212. The root canal space was filled with one of the ethanolic extracts of propolis (Artvin or Tekirdağ mix [TM]), CHX 2%, Ca(OH)(2), or ethanol or phosphate-buffered saline for control. Canal dentin was sampled after 1 or 7 days by using a standard-size bur. The dentinal shavings were vortexed vigorously in phosphate-buffered saline, and aliquots were cultured on tryptone soy agar plates. Colonies were counted after 2 days of incubation. Statistical significance was set to 5%. RESULTS All experimental agents significantly reduced the number of the cultivable bacteria. CHX was the most potent disinfectant at both times. Compared with the ethanol control, no significant reduction in the number of colonies was found for the propolis extracts at day 1; however, significant reduction was found at day 7. The 2 propolis samples were statistically similar to each other and to Ca(OH)(2), but the TM sample was also similar to CHX at day 7. This has been linked to the greater concentration of flavonoids, a group of antibacterially active compounds, in the TM sample as determined by gas chromatography-mass spectrometry analysis. CONCLUSIONS The antimicrobial activity of the propolis samples tested in this study was between Ca(OH)(2) and CHX. Both propolis samples were antimicrobially effective; however, their activity did not exceed CHX.

The Effect of Occlusal Loading on the Microleakage of Class V Restorations

OBJECTIVE This in vitro study evaluated the microleakage of Class V cavities restored with a resin composite and different adhesive systems after occlusal loading. METHODS & MATERIALS Standardized box-shaped Class V cavities were prepared on the buccal side of 135 non-carious human premolars. The teeth were randomly divided into three groups of 45 premolars each and restored as follows: Group 1-two-step total-etch adhesive (Single Bond, 3M) + resin composite (Supreme, 3M ESPE); Group 2-two-step self-etch adhesive (Clearfil SE, Kuraray) + resin composite and Group 3-one-step self-etch adhesive (Xeno III, Dentsply) + resin composite. The restorations were finished with aluminum oxide discs (Sof-Lex, 3M). Fifteen teeth in each group received 10,000 x 100 N and 250 N occlusal loads, respectively, and the remaining 15 teeth served as the control. The premolars were immersed in 2% methylene blue for 24 hours. The dye penetration was examined under a stereomicroscope, and the results were statistically analyzed by Kruskal Wallis, Mann-Whitney U and Wilcoxon Signed Rank tests to determine differences between the groups. RESULTS Gingival margins showed more dye penetration than occlusal margins in all the tested groups (p<0.05). In all the tested adhesive systems, 100 N occlusal loading did not change dye penetration; however, Groups 1 and 2 exhibited better marginal sealing than Group 3 at the enamel margins under 250 N occlusal loading. CONCLUSION Within the limitations of this in vitro study, it may be concluded that enamel margins provided better marginal sealing than dentin/cementum margins and the two-step self-etch adhesive exhibited better marginal sealing than an all-in-one adhesive at the enamel margins under 250 N occlusal loading.

Evaluation of diagnostic radiopaque contrast materials used with calcium hydroxide

An evaluation of three different radiopaque materials used in combination with calcium hydroxide powder for diagnostic contrast was made. Diatrizoate meglumine (65%) and iothalamate meglumine (60%) compared favorably with barium sulfate (35%). Since barium sulfate has demonstrated problems by altering the manipulative properties of calcium hydroxide as well as demonstrating a residual radiopacity, there may be advantages to the use of resorbable diatrizoate or iothalamate compounds as alternatives. These soluble iodine compounds also make possible an excellent aqueous medium in which to mix calcium hydroxide.

Effect of Surface Treatments and Different Adhesives on the Hybrid Layer Thickness of Non-carious Cervical Lesions

This in vitro study observed and compared the resin and non-carious sclerotic dentin interfaces generated by three different adhesives and two different techniques, using a scanning electron microscope (SEM). Thirty-two human premolars, with buccal, non-carious cervical lesions, were used. The teeth were randomly divided into eight groups. Group 1: Sclerotic dentin was treated with Single Bond (3M). Group 2: After superficial sclerotic dentin was removed with a diamond bur (Diatech, Coltene), the dentin surfaces were treated with Single Bond. Group 3: Sclerotic dentin was treated with Clearfil SE Bond (Kuraray). Group 4: After superficial sclerotic dentin was removed with a diamond bur, Clearfil SE Bond was applied. Group 5: Sclerotic dentin was treated with Xeno III (Dentsply). Group 6: After superficial sclerotic dentin was removed with a bur, Xeno III was applied to the dentin surfaces. For Groups 7 and 8, after the superficial sclerotic dentin was removed with a diamond bur, Clearfil SE Bond, with an additional 37% phosphoric acid gel, was used on the sclerotic dentin surfaces in Group 7 and Xeno III was used in Group 8. In all groups, the cavities were restored with Filtek Supreme (3M). All the specimens were sectioned longitudinally and polished along the cut surface. The sections were treated with 37% orthophosphoric acid for five seconds, rinsed with water and treated with 5% NaOCL for 10 minutes. The specimens were then gold-sputter coated and evaluated under SEM. The thickness of the hybrid layer was measured on the gingival, occlusal and axial dentin interfaces. ANOVA was performed to determine whether there were any statistically significant differences in hybrid layer thickness. Post-hoc multiple comparisons were done with Tukeys test. Hybrid layer thickness was increased with all adhesives when superficial dentin was removed with a bur. Hybrid layer thickness showed significant differences between total-etch and self-etch systems.

Mercury Exposure in Dental Practice

Since elemental mercury is absorbed by dental professionals through direct skin contact or inhalation, the use of mercury in dental amalgam continues to be a controversial issue. In this study, the authors address the possible health risk of occupational exposure to mercury vapor in the dental office. The cytogenetic examination of leukocytes with alkaline comet assay and blood mercury levels with Atomic Absorption Spectrometer of dentists exposed to mercury vapor below 0.1mg/m(3) concentrations failed to find cytogenetic damage and related correlation. However, higher cytogenetic damage and blood mercury levels evaluated in controls from mercury intake by seafood consumption justifies additional study.

Lactate dehydrogenase activity in periodontal ligament cells stored in different transport media.

BACKGROUND Maintaining viability of periodontal ligament cells is important after an avulsion injury occurs. OBJECTIVE This study examined cell death and compared different transport media at varying times. Lactate dehydrogenase (LD) measurements were made on root surfaces of extracted teeth for evaluating the results of breakdown and necrosis of periodontal ligament cells. STUDY DESIGN Teeth were divided into three groups. Each was immersed in one of the following storage media: Hanks balanced salt solution, Custodiol solution (an organ storage medium), or sterile saline solution. I.D. measurements (an indicator of cell death) were made at 2, 6, 24, 72, and 168 hours after extraction. RESULTS When the LD levels were compared according to the time periods, a progressive increase of cell death was found to be statistically significant (p < 0.001). However, when the effects of both time periods and the kind of storage medium on the LD levels were examined, the LD levels of the saline solution storage medium were found to be significantly higher (p < 0.001) than that of the other two groups. CONCLUSIONS Both Hanks balanced salt solution and Custodiol appeared to be suitable transport media for maintaining cell viability, whereas saline solution was not.

Two-year clinical evaluation of three adhesive systems in non-carious cervical lesions.

OBJECTIVES: Adhesive systems are continuously being introduced to Dentistry, unfortunately often without sufficient clinical validation. The aim of this study was to evaluate the clinical performance of cervical restorations done with three different adhesive systems. MATERIAL AND METHODS: 158 non-carious cervical lesions of 23 patients were restored with a nanofilled composite resin (Filtek Supreme, 3M/ESPE) combined with Single Bond (3M/ESPE, group SI), Clearfil SE (Kuraray Medical Inc., group CL) and Xeno III (De Trey Dentsply, group XE). In groups SI-B, CL-B and XE-B, the outer surface of the sclerotic dentin was removed by roughening with a diamond bur before application of the respective adhesive systems. In groups CL-BP and XE-BP, after removal of the outer surface of the sclerotic dentin with the bur, the remaining dentin was etched with 37% phosphoric acid and the self-etch adhesive systems Clearfil SE and Xeno III were applied, respectively. Lesions were evaluated at baseline, and restorations after 3 months, 1 year and 2 years using modified USPHS criteria. RESULTS: After 2 years, no significant difference was found between the retention rates of the groups (p >0.05). Although groups CL and SI showed significantly better marginal adaptation than group XE (p 0.05). After 2 years no significant difference was observed among the marginal staining results of all groups (p>0.05). CONCLUSION: Although all adhesive systems showed similar retention rates, Clearfil SE and Single Bond showed better marginal adaptation than Xeno III after 2 years of follow-up.Objectives Adhesive systems are continuously being introduced to Dentistry, unfortunately often without sufficient clinical validation. The aim of this study was to evaluate the clinical performance of cervical restorations done with three different adhesive systems. Material and methods 158 non-carious cervical lesions of 23 patients were restored with a nanofilled composite resin (Filtek Supreme, 3M/ESPE) combined with Single Bond (3M/ESPE, group SI), Clearfil SE (Kuraray Medical Inc., group CL) and Xeno III (De Trey Dentsply, group XE). In groups SI-B, CL-B and XE-B, the outer surface of the sclerotic dentin was removed by roughening with a diamond bur before application of the respective adhesive systems. In groups CL-BP and XE-BP, after removal of the outer surface of the sclerotic dentin with the bur, the remaining dentin was etched with 37% phosphoric acid and the self-etch adhesive systems Clearfil SE and Xeno III were applied, respectively. Lesions were evaluated at baseline, and restorations after 3 months, 1 year and 2 years using modified USPHS criteria. Results After 2 years, no significant difference was found between the retention rates of the groups (p >0.05). Although groups CL and SI showed significantly better marginal adaptation than group XE (p<0.05) at 2 years, no significant difference was found between the marginal adaptation of the groups SI-B, CL-B and XE-B (p>0.05). After 2 years no significant difference was observed among the marginal staining results of all groups (p>0.05). Conclusion Although all adhesive systems showed similar retention rates, Clearfil SE and Single Bond showed better marginal adaptation than Xeno III after 2 years of follow-up.

Examination of gutta-percha cones for microbial contamination during chemical use.

Objective: The aim of this study was to evaluate the degree of microbial contamination in packaged gutta-percha cones before and during use in clinical conditions. Material and Methods: Sealed packages of #15-40 gutta-percha cones were opened under aseptic laboratory conditions. Two gutta-percha cones from each size were randomly drawn and added to tubes containing glass beads and 750 μL of saline. The tubes were vortexed, serially diluted and samples of 250 μL were cultured on agar plates. The plates were incubated at 37°C for 3 days and colonies were counted. The initially sampled packages were distributed to 12 final year dental students. The packages were collected at the end of the first and the third clinical practice days and sampled as described above. Results: Baseline microbial counts did not exceed 3 CFU. At the end of the first and the third day, additional contamination was found in five and three of the packages, respectively. The ratio of contaminated packages at the first day and the third day was not significantly different (z-test; p > 0.05). The numbers of microorganisms cultured at the first day (8 ± 9.9 CFU) and the third day (4.5 ± 8.3 CFU) were not significantly different (Wilcoxon signed-rank test; p > 0.05). No significant correlation was found between the number of filled root canals and cultured microorganisms at either the first day (Spearmans rho; r = 0.481, p = 0.113) or the third day (r = -0.034, p = 0.917). Conclusions: Gutta-percha cones taken directly from manufacturers sealed package harbored microorganisms. Clinical use of the packages has been found to be associated with additional contamination of the gutta-percha cones. The counts of cultured microorganisms did not correlate well with the number of filled root canals.

Volumetric Evaluation of Void/Gap Formation and Microleakage Cementing Fiber Posts on Extracted Teeth with Three Different Cements: Void Formation and Microleakage

PURPOSE To evaluate microleakage in roots restored with fiber posts cemented using three different luting cements, to measure the volume of voids/gaps within the obturated/postcemented root canals, and to examine whether microleakage and the volume of voids/gaps were correlated. MATERIALS AND METHODS Thirty-six extracted human mandibular incisors were decoronated, and the root canals were obturated using gutta-percha and sealer in the experimental groups (n = 30). Six roots were used as controls. A standard post space was prepared, and an identically sized fiber post was cemented in each experimental specimen using one of three luting cements (Panavia F2.0, Bifix SE, GC FujiCEM; n = 10 each). The specimens were scanned using micro-computed tomography, and the volume of voids/gaps was determined. The specimens were then subjected to a fluid filtration assay to evaluate microleakage. RESULTS The volume of voids/gaps was significantly lower in the GC FujiCEM group, and significantly less microleakage occurred in the Bifix SE group compared with other groups (both p < 0.001). A significant correlation between the volume of voids/gaps and leakage was found only in the Panavia F2.0 group (p = 0.003; r = 0.830). No such correlation was found in the analysis of all groups combined. CONCLUSIONS The group with the greatest volume of voids/gaps (Bifix SE) showed the least microleakage, and the group with the smallest volume of voids/gaps (GC FujiCEM) showed the most microleakage. Panavia F2.0 ranked between and exhibited significant correlation.

Clinical evaluation of combined surgical/ restorative treatment of gingival recession-type defects using different restorative materials: A randomized clinical trial

Background/purpose An ideal therapeutic procedure for the treatment of gingival recession associated with an NCCL has presented a challenge to clinicians. Various dental materials and surgical approaches have been used to manage gingival recessions associated with NCCLs for the most predictable combined surgical/restorative treatment. The objective of this study was to evaluate the treatment of gingival recessions associated with non-carious cervical lesions (NCCL) using a modified coronally advanced flap (MCAF) in combination with a connective tissue graft (CTG) on restored root surfaces. Materials and methods Twenty-three systemically healthy subjects, who were positive for the presence of three cervical lesions associated with gingival recessions in three different adjacent teeth, were enrolled in the study. The NCCL were each restored prior to surgery by using one of three different materials: nanofilled composite resin (NCR), resin-modified glass ionomer cement (RMGI) or giomer. The gingival recession defects were treated by CTG. Results Inter-group differences were not statistically significant for probing depth (PD), relative recession height (rRH), relative clinical attachment level (rCAL), keratinized tissue width (KTW) or keratinized tissue thickness (KTT) (p > 0.05) among the groups at any time. The mean percentage of defect coverage was 71.18 ± 23.16% for NCR + CTG group; 71.33 ± 22.33% for RMGI + CTG group; and 64.23 ± 20.33% for giomer + CTG group at 1 year postoperatively (p > 0.05). Conclusion The combined surgical/restorative treatments provided successful clinical results. Giomer + CTG may be less effective compared to other groups for treatment of gingival recession associated with NCCL.