Effects of aging and inflammation on catalase activity in human dental pulp.

OBJECTIVES: In this study, it was aimed to examine the catalase activity in clinically healthy and caries-related inflamed symptomatic human dental pulps of young and old individuals. DESIGN: Sixty pulp samples from young and old healthy donors, were collected depending on pulpal status. 48 samples were used for spectrophotometric analysis and 12 samples for immunohistochemistry. Healthy pulps were maintained from non-carries, extracted third molars. Reversible and irreversible pulpitis samples were obtained by pulp extirpation during endodontic treatment. Following homogenization catalase enzyme activity was determined by spectrophotometry. Additionally, two pulp tissue samples from each group were fixed and evaluated for catalase immunoreactivity. RESULTS: Catalase enzyme activity in old healthy pulp samples were significantly higher than healthy young samples (p ≤ 0.05). Reversible and irreversible pulpitis samples indicated significantly decreased activity compared to healthy samples in elderly group (p ≤ 0.05). Young reversible pulpitis samples showed significantly increased catalase activity when compared to irreversible pulpitis and the reversible pulpitis samples in elderly group (p ≤ 0.05). Immunohistochemical evaluation indicated that there was intense catalase immunoreactivity in young patients with reversible pulpitis compared with reversible pulpitis in elderly group. However, weak immunoreactivity was observed in young irreversible pulpitis and elderly reversible pulpitis samples. CONCLUSIONS: The pulp tissues presented different levels of catalase activities against pulpitis and aging.

Effect of Sodium Hypochlorite Irrigation with and Without Surfactant on Maximum Operative Torque and Vertical Force of Nickel-Titanium Endodontic Instruments.

Objectives: This study aimed to evaluate the effects of root canal irrigation on maximum operative torque and vertical force of Wave One Gold Primary (WOG), Reciproc Blue R25 (RB) and Protaper Next X2 (PTN) endodontic rotary instruments during simulated root canal preparation in the presence and absence of a surfactant "benzalkonium chloride". Material and Methods: A custom-made automated irrigation and torque/force analyzing device connected with endomotor was used for the study. Acrylic resin blocks with simulated curved root canals of 35° were randomly assigned to 6 groups for each file. The following irrigants were used during simulated root canal preparation with continuous rotation or reciprocation motion with pecking mode: 5% NaOCl and 5% NaOCl with 0.84% benzalkonium chloride. Maximum torque and vertical force values ​​of files were recorded during preparation. Results: BAC addition to NaOCl did not significantly affect maximum torque values of instruments (p>0.05). WOG generated lowest torque value compared with PTN and RCB in both groups (p<0. 05). RB generated higher vertical force compared with WOG and PTN instruments in NaOCl+BAC group. The surface modifier decreased the maximum force value of WOG instrument (p<0.05). Discussion: Surfactan addition to NaOCl had no negative effects on maximum torque and force of the instruments.