Evaluation of human pulp tissue response following direct pulp capping with a self-etching adhesive system containing MDPB.

This study evaluated the human pulp tissue response following direct pulp capping with Clearfil Protect Bond (CPB) self-etching adhesive containing an antibacterial monomer MDPB. The pulps of third molar teeth were exposed by the removal of carious tissue. In an experimental group, CPB was applied to the exposed pulp and dentin. In the control groups, Clearfil SE Bond (CSE) or calcium hydroxide-based cement (CH) was applied to the exposed pulp surfaces. All teeth were filled with resin composite, extracted after 90 days, and the pulp responses were histologically analyzed. No severe inflammation or soft tissue disorganization was observed in CPB and CH groups. CSE group exhibited a disorganized odontoblastic layer and severe inflammatory infiltration. No hard tissue formation was observed in CSE group, and CH formed more of a hard tissue formation than CPB. CPB induced an acceptable healing response when directly applied to exposed pulps with bacterial contamination.

In vivo and in vitro evaluations of microleakage around Class I amalgam and composite restorations.

This study evaluated and compared microleakage values of in vivo and in vitro placed Class I amalgam restorations with or without three different lining materials and posterior composite restorations with two dentin bonding agents. For the in vivo group, 72 standardized Class I cavities were prepared on the occlusal surfaces of molars scheduled for extraction. The test groups (n = 12) were: amalgam without lining (A), amalgam with cavity varnish (A+C), amalgam with Clearfil SE Bond (A+CSE), amalgam with Clearfil 2V (A+C2V), composite with Clearfil SE Bond (C+CSE) and composite with Protect Bond (C+PB). The restored teeth were extracted after seven days. The same grouping, materials and techniques were used in 72 extracted molars for the in-vitro part of the study. The specimens were immersed in basic fuchsin for 24 hours and sectioned. Microleakage was examined and scored at 20x magnification. Statistical analyses were performed with the Kruskal-Wallis and Mann-Whitney U-tests with the 5% level of significance. Overall, the in vivo and in vitro test groups were not different from each other. No significant differences in microleakage values were observed between the unlined and lined amalgam groups (p > 0.05). However, since lined amalgam restorations did not reveal any marginal leakage, the application of an adhesive bonding material under the amalgam restorations can be considered. In general, cavity varnish was not as effective as adhesive bonding agents in preventing microleakage in amalgam restorations. Composite restorations demonstrated higher leakage values than amalgam restorations (p < 0.05), except for A+C (p > 0.05) in the in vivo group. There was no significant difference between the two composite groups for in vitro and in vivo conditions (p > 0.05).

The effect of endodontic therapy on periapical exudate neutrophil elastase and prostaglandin-E2 levels.

This study aimed to investigate periapical exudate neutrophil elastase (NE) and prostaglandin E2 (PGE2) levels and their relationships with clinical symptoms, and to determine the changes of their levels following first treatment visit. Periapical exudate samples were collected from the canals of 34 nonvital single-rooted teeth at two sequential treatment visits. Periapical exudate NE and PGE2 levels were found to be higher in the presence of clinical symptoms (pus discharge, swelling) (p < 0.05). The canals of teeth with larger periapical radiolucent area (>or=1 cm) contained more PGE2 levels than with smaller ones (<1 cm) (p < 0.05). Periapical exudate NE levels were significantly correlated with PGE2 levels (p < 0.05), and their levels at first treatment visit did not change following root canal therapy (p > 0.05). The periapical exudate NE and PGE2 levels may regulate periapical disease expression, but the results of this study were unable to reveal this association.

Neutrophil elastase levels in periapical exudates of symptomatic and asymptomatic teeth.

The aim of this study was to determine neutrophil elastase levels (NE) in periapical exudates and to evaluate its relationship with clinical signs and symptoms of endodontically involved teeth. A total of 42 teeth with periapical periodontitis of 37 patients were clinically examined and spontaneous pain, swelling, pain on palpation or percussion, sinus tract formation and pus discharge were recorded. Additionally, periapical lesion size was measured on periapical radiographs. Periapical exudate samples were obtained during routine root canal treatment by using paper points. Enzyme levels were determined by spectrophotometric assays using the NE specific substrate N-methoxysuccinil-Ala-Ala-Pro-Val-p-nitroanilide. The teeth with signs and symptoms showed higher NE levels than the teeth without symptoms (p<0.05). The differences were significant when NE levels were presented as total amounts instead of concentration. This study demonstrated that NE in periapical lesions related with clinical symptoms and total enzyme amount may be more reliable mode of data presentation.