Evaluation of the shaping ability of different rotary file systems in severely and abruptly curved root canals using cone beam computed tomography.

Background: When selecting an instrument for canal preparation, it is important to consider several parameters that influence the shaping efficiency, including instrument design, metallurgy, and operating motion. This study aimed to evaluate the shaping ability of the ProTaper Next (PTN), WaveOne Gold (WOG), and XP-endo Rise Shaper (XPRS) rotary systems in severely and abruptly curved root canals using cone beam computed tomography (CBCT) and ImageJ software.

Materials And Methods: Forty-eight mesial root canals of the mandibular first molars were assigned equally to three groups: PTN, WOG, and XPRS.

Efficacy of a newly designed angulation-adjustable film holder for reducing cone-cutting errors and saving time in horizontal tube-shift technique by dental students.

Objectives: To compare the cone-cutting error frequency and the X-ray cone alignment time in the horizontal tube-shift technique between the newly designed angulation-adjustable and the extension cone paralleling (XCP) holders, by dental students.

Materials And Methods: Two film holders were assigned for a random test. The mandibular left first molar position of a laboratory phantom head was used.

Outward fluid flow reduces inward diffusion of bacterial lipopolysaccharide across intact and demineralised dentine.

Objective: To examine the ability of outward fluid flow (OF) on resisting the inward diffusion of bacterial lipopolysaccharide (LPS) across the demineralised dentine (DD) in comparison with that across the intact dentine (ID).

Design: Twenty ID discs were prepared from freshly extracted human third molars. After etching both dentine surfaces, hydraulic conductance (L(p)) of the dentine was measured.

Influence of the pulpal components on human dentine permeability in vitro.

Aim: To examine the influence of the retained pulpal components on permeability of human dentine by monitoring drug diffusion.

Methodology: Twelve intact dentine discs were prepared from freshly extracted human third molars. The dentine surface on the enamel side was etched with 10% polyacrylic acid for 30 s.

Facilitation of iontophoretic drug delivery through intact and caries-affected dentine.

Aim: To investigate the facilitative role of iontophoresis in drug delivery through intact and caries-affected dentine into the pulp.

Methodology: Forty-eight intact dentine or caries-affected dentine discs were prepared from freshly extracted human third molars. The hydraulic conductance was measured before and after the experiments.