ENDO, 01/2009

Preserving the dental pulp, or part of it, is important when treating a vital tooth with an exposed pulp, particularly if the tooth is immature and root formation is incomplete. In this paper, the practical aspects of pulp capping and partial pulpotomy are discussed, supported by clinical cases and histological examples. The indications, clinical factors, materials and treatment procedures are considered along with the expected prognosis. Keywords: calcium hydroxide, mineral trioxide aggregate, pulp capping, pulpotomy

It is well established that thorough cleaning and shaping of the root canal (RC) system is essential for successful RC treatment. Current chemomechanical cleaning methods do not always achieve this goal. Due to the high energy content and specific characteristics of laser light, laser treatment has been proposed for both cleaning and disinfecting the RC system. This paper reviews the literature covering the effect of CO2, diode, Nd:YAG, KTP, Er:YAG and Er,Cr:YSGG lasers on the RC wall, together with the interaction between laser light and target, and the inherent limitations of laser use inside the RC system. On the basis of recent literature, it can be concluded that certain lasers can help in removing the smear layer and debris, they can modify the morphology of the RC wall and that there are inconsistent findings with regard to interactions between lasers and the RC wall, perhaps due in part to variations in irradiation parameters (a lack of standards for irradiation parameters is the cause). The use of laser energy to induce cavitation and acoustic streaming of irrigants is now being explored as an alternative for ultrasonic activation. Unfortunately, there is still much to be proven regarding the clinical usefulness of lasers, as there are no correctly designed clinical studies that include non-laser control groups and evaluate endodontic treatment outcome following the use of lasers. Keywords: cavitation, EDTA, endodontics, laser, root canal, smear layer

This case report looks at a case of traumatic avulsion and subsequent apexification of a maxillary permanent incisor of a 6-year-old boy and a 10-year follow-up is reported. Treatment included apexification of the tooth with incomplete root formation using mineral trioxide aggregate and restoration of the immature root with a zirconia post and a coronal composite restoration. At the 10-year follow-up the tooth was asymptomatic, functional and showed radiographically intact periapical tissues. Keywords: adhesive restoration, apexification, avulsion, dental trauma, immature root, MTA

Aim: To describe unusual variations in the root morphology and root canal systems of a first maxillary molar retreated for pain and prosthetic reasons. Summary: Normally maxillary first molar teeth have three single roots and almost always have four canals. A 46-year-old patient presented for non-surgical retreatment prior to undergoing prosthetics. The maxillary first molar exhibited three distinct root canals in the mesiobuccal root canal system. The incidence of three canals in the mesiobuccal root canal is very rare. However, this anatomical deviation may present an unfavourable outcome if clinicians fail to recognise the difficulties. Conclusions: Root morphology may present a challenge for clinicians during root canal treatment. Thorough clinical and radiographic interpretation is important in recognising anomalous root and root canal systems. Finally, successful root canal treatment requires an accurate diagnosis of the root canal system using available aids. Keywords: first molar, retreatment, unusual anatomy

Aim: The aim of this report was to describe the steps of a diagnostic protocol used to recognise the presence of a third root canal in first and second maxillary premolars at an early stage. Materials and methods: A total of 43 maxillary first premolars and 51 maxillary second premolars were endodontically treated in a private practice between 1999 and 2004 after having been examined clinically and radiographically. Results: A third root canal was present in 4 out of the 43 first maxillary premolars (9.3%) and in 1 out of the 51 (1.9%) second maxillary premolars that were endodontically treated. All of the five cases were diagnosed preoperatively. The early interception of an anatomical variant allows the clinician to choose the best operative strategy for a specific tooth in terms of access cavity design, canal shaping and cleaning, filling and post-endodontic restoration. Conclusions: Radiographic and clinical examinations of maxillary premolars are essential for early diagnosis of the presence of a third root canal. A careful examination of the pulp chamber floor can help to find the orifice of a third root canal intra-operatively. Keywords: anatomical variants, maxillary premolars, radicular anatomy, three-canal maxillary premolars

The establishment of apical foramen patency and its maintenance during chemomechanical preparation has been considered an important step in the cleaning and disinfection of the apical part of the root canal. The purpose of this study was to evaluate the adaptation of endodontic files to the apical foramen of extracted teeth using scanning electron microscopy. Twenty mandibular first premolars were divided into two groups. In group 1, adaptation to the apical foramen was examined by taking note of the first file to bind in the canal when moved 1 mm beyond the foramen. In group 2, adaptation was evaluated using a file one size larger than that of group 1. Files were fixed in the canal and adaptation to the contour of the apical foramen was examined under a scanning electron microscope. The area occupied by the file in relation to the foramen area was also calculated. Findings demonstrated that no instrument, regardless of the group, adapted to the apical foramen. The foraminal area occupied by the instrument cross-section ranged from 7% to 54%. Lack of adaptation was due to the much larger diameter of the apical foramen and/or its irregular shape in relation to the patency file. Keywords: apical foramen, dental anatomy, endodontic treatment, patency files, root canal preparation