Unilateral fusion of a supernumerary tooth to a maxillary permanent lateral incisor: a report of a rare case.

A supernumerary tooth is an additional entity to the normal series of teeth that may occur in isolation or may be fused to a normal counterpart. Diagnosis and delineation of an accurate treatment plan in cases involving supernumerary teeth are often a challenge. This report describes a case of unilateral fusion of a supernumerary tooth to a maxillary permanent lateral incisor in which a conservative approach was used to reach a favorable outcome.

Assessment of the separation incidence of reciprocating WaveOne files: a prospective clinical study.

INTRODUCTION: Despite metallurgical advancements in the nickel-titanium file manufacturing process, file separation remains a concern. The purpose of this prospective clinical study was to assess the separation incidence of the reciprocating WaveOne file (Dentsply Tulsa Dental Specialties, Tulsa, OK) when used to prepare root canals of posterior teeth. METHODS: File separation incidence was assessed over an 18-month period in which 4 experienced and calibrated endodontists performed conventional endodontic treatment on posterior teeth using the WaveOne file system. The separation incidence was determined based on both the number of teeth and the number of canals instrumented during this time period. RESULTS: A total of 2,215 canals (711 teeth) were treated. Three instruments (two 21.06 and one 25.08) separated during use and were deemed to be irretrievable. The overall instrument separation incidence in relation to the number of canals shaped was found to be 0.13% (0.42% teeth). CONCLUSIONS: Based on the results of this study, the incidence of endodontic instrument separation when using the WaveOne reciprocating file was considerably low.

Influence of single-file endodontics on apical transportation in curved root canals: an ex vivo micro-computed tomographic study.

INTRODUCTION: More information regarding the ability of single files to maintain the original canal position is required before adopting a single-file approach to cleaning and shaping. This study compares apical transportation in curved root canals when instrumenting with a single WaveOne (WO) file (Dentsply Tulsa Dental Specialties, Tulsa, OK) in a reciprocating motion with that incurred when using a sequence of Twisted Files (TFs; SybronEndo, Orange, CA) in a continuous rotating motion. METHODS: Forty mesial canals of mandibular molars were evenly allocated into 2 balanced groups (n = 20) with a 17-mm average canal length and 20° average curvature. Canals were accessed in a conventional manner and instrumentation was completed with a single WO file or a series of TFs. The canals were instrumented according to the manufacturers' protocol. Apical transportation was assessed on a comparison of the pre- and postinstrumentation micro-computed tomographic scans at 1-, 2-, 3-, 4-, and 5-mm sections. One-way analysis of variance was performed to assess if a significant difference between systems exists. RESULTS: No significant difference (P > .05) was found between the WO and TF groups. Transportation in the mesial direction was of greater magnitude than distal transportation for both files systems. The mean transportation in the mesial direction was 100.1 ± 8.8 µm (WO group) and 101.0 ± 10.9 µm (TF group) (P = .5), whereas distal transportation was found to be 80.9 ± 14.6 µm (WO group) and 60.3 ± 11.0 µm (TF group) (P = .3). CONCLUSIONS: The results suggest that no difference exists between the WO file system and the conventional multifile TF system when considering apical transportation in curved canals.