ichiro kinoshita

The amounts of apical enlargement have been a controversial issue for a long time. The enlargement of the apical part of the canal may severely impact the endodontic prognosis. Enlargement of the apical portion to a larger size may negatively affect the ability to control the filling material during root canal obturation. In addition, an open-apex increases the risk for overfilling which has been shown to be related with decreased success rate. The retreatment of a tooth with apically enlarged canal may be even impossible. Further preparation of an apically enlarged canal may increase the risk of iatrogenic errors and also excessive apical root weakness. The present article aimed to address in vitro and clinical studies on apical enlargement, effect of coronal pre-flaring on the size of the master apical file, and clinical applications of apical enlargement.

The nickel-titanium (Ni-Ti) alloys used in endodontics contain 56% Ni and 44% Ti. The 2 unique features related to clinical dentistry (i.e., shape memory effect and superelasticity) are due to the transition from austenite to martensite in Ni-Ti alloy. When a superelastic Ni-Ti alloy undergoes a low tensile loading, normal elastic behavior occurs. In fact, at higher tensile loads, the elastic stress may reach a level at which there is extended horizontal region of elastic strain. The shape-memory property of Ni-Ti is derived from an atomic arrangement different from that of alloys like stainless steel. The purpose of this paper was to review the unique features of this alloy and mechanism of corrosion.

Citation analysis is a suitable way to help us to identify research trends within a specific topic. The purpose of this study was to identify the 100 most cited articles in the field of dentistry published over the past 67 years. A comprehensive list of the most cited articles in dentistry was compiled using ISI Web of Science. The characteristics including number of citations, authors and journals were analyzed. The database resulted in 3,831 articles with 100 or more citations published between 1950 and 2017. Most of these articles had been published by the Journal of Clinical Periodontology, followed by the Journal of Periodontology, and Journal of Dental Research. Sokransky SS followed by Lindhe J, Nyman S, and Genco RJ had the most number of citations. The most cited articles in the field of dentistry allows for advances in this field and also provide useful information for direct future studies and patient care.

The aim of this randomized clinical trial was to compare the histologic pulp tissue response to one-step direct pulp capping (DPC) and miniature pulpotomy (MP) with mineral trioxide aggregate (MTA) after application of dexamethasone in healthy human premolars.
Methods and Materials: Forty intact premolars from 10 orthodontic patients, were randomly chosen for DPC (n=20) or MP (n=20). In 10 teeth from each group, after exposure of the buccal pulp horn, topical dexamethasone was applied over the pulp. In all teeth the exposed/miniaturely resected pulp tissue was covered with MTA and cavities were restored with glass ionomer. Teeth vitality was evaluated during the next 7, 21, 42, and 60 days. Signs and/or symptoms of irreversible pulpitis or pulp necrosis were considered as failure. According to the orthodontic schedule, after 60 days the teeth were extracted and submitted for histological examination. The Kruskal-Wallis and Fisher’s exact tests were used for statistical analysis of the data (P=0.05).
Although dexamethasone specimens showed less inflammation, calcified bridge, pulpal blood vasculature, collagen fibers and granulation tissue formation were not significantly different between the groups (P>0.05).
Topical dexamethasone did not hindered pulp healing but reduced the amount of underlying pulpal tissue inflammation after DPC and MP in healthy human premolars.