ABSTRACT
@#Mineral Trioxide Aggregate (MTA) is a biocompatible, antibacterial, radiopaque, and dimensionally stable material after setting. Furthermore, it can set in the presence of moisture, and has a high sealing ability. The objectives of this study were to describe managements of three different exceptionally complicated endodontics cases using MTA, and to evaluate its outcomes of using MTA in long-term follow-up based on modern concept of endodontics. Case #1: A 23-year-old patient diagnosed with combined endodontic-periodontal lesion with palatogingival groove of maxillary right lateral incisor was referred to our department. A treatment of interdisciplinary approach involving root canal treatment, periodontal initial therapy, root resection, guided tissue regeneration and bone grafting was performed. The case showed complete clinical normalcy and radiographic healing on periapical radiograph after 3-year follow-up, and outcome was defined as healed. Case #2: A 33-year-old patient had a perforated resorptive lesion to mesial external root surface of tooth 21. The diagnosis was perforating internal root resorption with pulp necrosis and asymptomatic apical periodontitis. A treatment plan of revascularization with MTA coronal plug was made. The case #2 showed clinical normalcy, complete healing of alveolar bone and incomplete healing of resorptive area radiolucency on CBCT after 4-year follow-up, and outcomes were defined as healing. Case #3: An 18-year-old patient with pulp necrosis and chronic apical abscess at immature left maxillary lateral incisor with open apex received treatment of apexification with MTA and followed-up regularly. The case showed complete clinical normalcy and radiographic healing on periapical radiograph, but incomplete healing of the periapical lesion was observed on CBCT after 4-year follow-up. This outcome was defined as healing. 1. MTA may be a suitable material for use as a plug material that prevents infection and blood flow to the main root canal during periodontal surgery, perforation repair and internal root resorption filling and root canal obturation of apexification treatment. 2. Extruded MTA through the apical foramen may not have an adverse effect to periapical tissues, also could be result in osseous healing. Moreover, extruded MTA might have a property to resorb. 3. Tooth discoloration could be a potential drawback of white MTA when it is used as endodontic repair material and the discoloration tends to continuously develop for a while.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the inhibition of Streptococcus oligofermentans (So) on Streptococcus mutans (Sm) and the producibility of hydrogen peroxide by So under the influence of glucose concentration environment.</p><p><b>METHODS</b>The inhibition between So and Sm was observed by plating method under the different glucose concentration environment. The initial synthesis rates and production of hydrogen peroxide by So were determined under the different glucose concentration environment by 4-aminoantipyine-horseradish peroxidase method at A(510).</p><p><b>RESULTS</b>Under 0, 10 and 50 mmol/L glucose environment, the inhibition of So on Sm was evident. When both Sm and So were inoculated at the same time, the ratio of inhibition area by bacterial membrane area was 0.202 ± 0.005, 0.467 ± 0.025, 0.468 ± 0.028 under 0, 10, 50 mmol/L glucose environment. When So was cultivated first and then Sm applied, the ratio was 0.394 ± 0.004, 0.811 ± 0.075 and 0.816 ± 0.007 under 0, 10 and 50 mmol/L glucose environment respectively. The inhibition under 10 and 50 mmol/L glucose environment were more significant than that under non-glucose environment. There was no significant difference between these two glucose concentrations (P > 0.05). The initial synthesis rates of H2O2 by So under the 10 mmol/L [(23.573 ± 0.263) µmo×L(-1)×min(-1)] and 50 mmol/L [(23.337 ± 0.473) µmol×L(-1)×min(-1)] glucose were higher than without glucose[(10.513 ± 0.516) µmol×L(-1)×min(-1)], P < 0.05. H2O2 was not detected in 1000 mmol/L glucose. However, the production of H2O2 by So under 0 mmol/L glucose was higher than other glucose concentrations (P < 0.05).</p><p><b>CONCLUSIONS</b>The capability of the inhibition of So on Sm was affected by glucose environment and was much stronger under certain glucose concentrations (10, 50 mmol/L).</p>
Subject(s)
Antibiosis , Dose-Response Relationship, Drug , Glucose , Metabolism , Hydrogen Peroxide , Metabolism , Streptococcus , Metabolism , Physiology , Streptococcus mutans , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To investigate the effect of environmental oxygen on the inhibition between Streptococcus oligofermentans (So) and Streptococcus mutans (Sm) and the producibilities of hydrogen peroxide by So.</p><p><b>METHODS</b>The aerobic and anaerobic environment was established by the carbon dioxide cultivation. The inhibition between So and Sm was observed by plating method. The production and synthesis rates of hydrogen peroxide by So were determined in both aerobic and anaerobic environment by 4-ATTP-horseradish peroxidase method at A(510).</p><p><b>RESULTS</b>When both Sm and So were inoculated at the same time, Sm was not inhibited under the anaerobic environment, vice versa. Sm was slightly inhibited by So under the aerobic environment, the inhibition area was 1/5 of all bacterial membrane. When So was cultivated first and then Sm applied, So could inhibite Sm growth under both anaerobic and aerobic conditions. The inhibition area was 1/5 of bacterial membrane under the anaerobic environment, and 4/5 under the aerobic environment. When Sm was cultivated first and then So applied, So was unable to proliferate under both conditions. During the logarithmic phase, the production of H2O2 by So under the aerobic environment was higher than under the anaerobic environment (P < 0.05). The initial synthesis rate of H2O2 by So during growth cycle under the anaerobic condition was (11.84 ± 3.97) µmol/L per minute, which was only 49% of that under the aerobic environment [(24.13 ± 4.46) µmol/L per minute].</p><p><b>CONCLUSIONS</b>The oxygen has the effect on the inhibition between So and Sm, and the inhibition in the aerobic environment is much stronger than in the anaerobic environment. The synthesis ability of hydrogen peroxide by So under the aerobic environment is higher than under the anaerobic environment.</p>