Clinical and Radiographic Evaluation of a Resin-Based Root Canal Sealer: 10-Year Recall Data

Objectives. This retrospective clinical and radiographical study evaluated the 10-year outcome of one-visit endodontic treatment with gutta-percha and a methacrylate resin-based sealer. Methods. From an initial sample size of 180 patients, 89 patients with 175 root canals responded to a recall. Treatment outcome was based on predetermined clinical and radiographic criteria. Results. Root canals had been adequately filled to the working length in 80 teeth (89.88%), short in 6 instances (6.74%), while 3 (3.37%) with extrusion immediate postoperatively, showed no sealer in periradicular tissues. The difference in the outcomes of treatments with respect to age, gender, preoperative pulp or periapical status, the size of periapical lesions and the type of permanent restorations were not statistically significantly different (P > 0.05). Overall, 7 (7.86%) cases were considered clinically and radiographically a failure. A life table analysis showed a cumulative probability of success of 92.13% after 10 years with a 95% confidence interval of 83.0 to 94.0. Conclusions. The results of this retrospective clinical and radiographical study suggest that the tested methacrylate-resin based sealer used with gutta-percha performed similarly to other root canal sealers over a period 10 years. Clinical Implications. Considering the success rate after 10 years of this methacrylate resin-based sealer can be recommended as an alternative to other commonly used root canal sealers

Interrupted orthodontic force results in less root resorption than continuous force in human premolars as measured by microcomputed tomography

Introduction. Root resorption is an undesirable but very frequently occurring sequel of orthodontic treatment. The aim of this study was to compare root resorption caused by either continuous (CF) or interrupted (IF) orthodontic force. Material and methods. The study was performed on human subjects on 30 first upper and lower premolars scheduled for extraction for orthodontic reasons. During four weeks before extraction 12 teeth were subjected to either CF or IF. The force was generated by a segmental titanium-molybdenum alloy cantilever spring that was activated in buccal direction. Initially a force of 60 CentiNewton was used in both CF and IF groups, the force in the former, however, was reactivated every week for 4 weeks. There was no reactivation of force in the IF group after initial application. A morphometric analysis of root resorption was performed by microcomputed tomography and the extent of tooth movement was measured on stone casts. Furthermore, a Tartarate-Resistant Acidic Phosphatase activity (TRAP), the marker enzyme of osteoclasts and cementoclasts, was determined by histochemical method. The Mann-Whitney U test was used to compare the difference in measured parameters between treatment and control tooth groups. Results. The number of resorption craters was significantly higher and their average volume almost twice as large in the CF compared to the IF group (p < 0.05). However, the distance of tooth displacement was similar for both groups. Cementoclasts were detected with the TRAP technique on the surface of two teeth only; both were subjected to continuous force. Conclusions. The use of IF leads to less destruction of root structure as opposed to continuous force while the same tooth movement was achieved

Adaptation and penetration of resin-based root canal sealers in root canals irradiated with high-intensity lasers

This research analyzed the quality of resin- based sealer adaptation after intracanal laser irradiation. Extracted teeth (n = 168) were root canal treated and divided into four groups, according to dentin surface treatment: no laser; Nd: YAG laser (1.5 W, 100 mJ, 15 Hz); diode laser (2.5 W in CW), and Er: YAG laser (1 W, 100 mJ, 10 Hz). The teeth were divided into four subgroups according to the sealer used: AH Plus, EndoREZ, Epiphany, and EpiphanySE. For testing the sealing after root canal obturation, the penetration of silver nitrate solution was measured, whereas to evaluate the adaptation and penetration of the sealer into the dentin, environmental scanning electron microscopy (ESEM) was used. The ESEM images were analyzed using a four-grade criteria score by three evaluators. The inter-examiner agreement was confirmed by Kappa test and the scores statistically compared by the Kruskal-Wallis'test (p < 0.05). Both adaptation and sealer penetration in root canals were not affected by the laser irradiation. Nd: YAG and diode laser decreased the tracer penetration for AH Plus, whereas EndoREZ and EpiphanySE performances were affected by Nd: YAG irradiation (p < 0.05). It can be concluded that intracanal laser irradiation can be used as an adjunct in endodontic treatment; however, the use of hydrophilic resin sealers should be avoided when root canals were irradiated with Nd: YAG laser. (C) The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ Cruzeiro Sul, Sch Dent, BR-01506000 Sao Paulo, BrazilUniv Ibirapuera, Sch Dent, BR-04661100 Sao Paulo, BrazilUniv Estadual Paulista, BR-12245000 Sao Jose Dos Campos, BrazilUniv Connecticut, Ctr Hlth, Farmington, CT 06032 USAUniv Sao Paulo, BR-05508000 Sao Paulo, BrazilUniv Estadual Paulista, BR-12245000 Sao Jose Dos Campos, Brazi

Improved delineation with diffusion weighted imaging for laryngeal and hypopharyngeal tumors validated with pathology

OBJECTIVE: This study aims to determine the added value of a geometrically accurate diffusion-weighted (DW-) MRI sequence on the accuracy of gross tumor volume (GTV) delineations, using pathological tumor delineations as a ground truth. METHODS: Sixteen patients with laryngeal or hypopharyngeal carcinoma were included. After total laryngectomy, the specimen was cut into slices. Photographs of these slices were stacked to create a 3D digital specimen reconstruction, which was registered to the in vivo imaging. The pathological tumor (tumor HE) was delineated on the specimen reconstruction. Six observers delineated all tumors twice: once with only anatomical MR imaging, and once (a few weeks later) when DW sequences were also provided. The majority voting delineation of session one (GTV MRI) and session two (GTV DW-MRI), as well as the clinical target volumes (CTVs), were compared to the tumor HE. RESULTS: The mean tumor HE volume was 11.1 cm 3, compared to a mean GTV MRI volume of 18.5 cm 3 and a mean GTV DW-MRI volume of 15.7 cm 3. The median sensitivity (tumor coverage) was comparable between sessions: 0.93 (range: 0.61-0.99) for the GTV MRI and 0.91 (range: 0.53-1.00) for the GTV DW-MRI. The CTV volume also decreased when DWI was available, with a mean CTV MR of 47.1 cm 3 and a mean CTV DW-MRI of 41.4 cm 3. Complete tumor coverage was achieved in 15 and 14 tumors, respectively. CONCLUSION: GTV delineations based on anatomical MR imaging tend to overestimate the tumor volume. The availability of the geometrically accurate DW sequence reduces the GTV overestimation and thereby CTV volumes, while maintaining acceptable tumor coverage

Development of a system for quantitative measurements of tooth mobility

PLEASE NOTE: This work is protected by copyright. Downloading is restricted to the BU community: please click Download and log in with a valid BU account to access. If you are the author of this work and would like to make it publicly available, please contact [email protected] (M.Sc.D.)--Boston University School of Graduate Dentistry, 1972. (Prosthodontics)Bibliography included.Tooth mobility may be an important parameter for determining the severity of the destruction of periodontal attachment apparatus. In evaluating the effectiveness of periodontal treatment the examination of tooth mobility is also considered significant. It is logical then, that the measurement of mobility of teeth for clinical and research purposes must be accurate. A mobility measuring device was developed, constructed and recordings made on three patients. The instrument is capable of recording tooth mobility accurately to 1/1000 of a millimeter. The device also has the advantage over other existing measuring devices in that mobility is related to a fixed reference point. ·The sensing portion of the equipment is fixed to a removable appliance and need not be adjusted or reset each time a measurement is made. In this manner the mobility of a tooth in its socket following treatment in periodontally involved patients can be observed. The recordings obtained suggest very little change in mobility between the pre-operative and post-operative periods of 3 weeks. A marked increase was noted at the 3 days post-operative recording. This increase reached its peak at 12 days, after which it decreased and remained level at the properative measurement. No significant decrease following subgingival instrumentation was noted after 21 days

A Review of Luting Agents

Due to the availability of a large number of luting agents (dental cements) proper selection can be a daunting task and is usually based on a practitioner’s reliance on experience and preference and less on in depth knowledge of materials that are used for the restoration and luting agent properties. This review aims at presenting an overview of current cements and discusses physical properties, biocompatibility and other properties that make a particular cement the preferred choice depending on the clinical indication. Tables are provided that outline the different properties of the generic classification of cements. It should be noted that no recommendations are made to use a particular commercial cement for a hypothetical clinical situation. The choice is solely the responsibility of the practitioner. The appendix is intended as a guide for the practitioner towards a recommended choice under commonly encountered clinical scenarios. Again, no commercial brands are recommended although the author recognizes that some have better properties than others. Please note that this flowchart strictly presents the author’s opinion and is based on research, clinical experience and the literature

The development and applications of replica techniques for use with scanning electron microscopy

PLEASE NOTE: This work is protected by copyright. Downloading is restricted to the BU community: please click Download and log in with a valid BU account to access. If you are the author of this work and would like to make it publicly available, please contact [email protected] (D.Sc.D.)--Boston University, School of Graduate Dentistry, 1973.Includes bibliography (leaves 199-209)With the introduction of the scanning electron microscope the knowledge on surface characteristics of the microtopography has increased tremendously. The unique features such as the great depth of field, the outstanding contrast and the three dimensional image make ·it possible to explore microstructures which were unknown. Stimulated by the successes of the practical applications in metallurgy, researchers in biology and medicine explored the possibilities of applications in their fields. Although specimen preparation involves less work than required for transmission electron microscopy it would be an understatement to assume that it is trouble free. All biological tissue shrinks when exposed to a high vacuum. This vacuum is one of the requirements during specimen preparation when a metal is evaporated to form a conductive layer on the specimen. Accelerated electrons interacting with the surface of the specimen will be conducted by this metal layer and by means of amplification of the signal produce an image on a cathode ray tube. It is the creation of specimen preparation artefacts which may lead to misinterpretation. Some artefacts induced by the vacuum are obvious as to their arteficial nature; others are subtle changes which may not be recognized as such. In order to determine as to whether artefacts are created during specimen preparation, replica techniques were developed which duplicate the specimens prior to exposure to the high vacuum of the metal evaporator. The original and positive replica were then prepared simultaneously for scanning electron microscope observation. A comparison between originals and replica specimens revealed that 1n observing biological tissues the introduction of artefacts is inevitable. Some artefacts were easily recognizable as such, others could very well be interpreted as being normal and in these cases the replicas provided in a decisive answer. A variety of controversial subjects in dentistry were investigated and the specimens replicated in either applying a hard or a soft replica technique. When hard biological tissues were investigated the hard replica technique was utilized; when no pressure on soft tissues was allowed a pressureless soft replica technique was applied. It can be concluded that the two techniques have a definite application in dental research with further possibilities in other sciences. The feasibility for longitudinal studies is a valuable asset to existing experimental design

Endodoncia adhesiva. Fundamentos, desarrollo y utilidad del sellador endodóntico a base de metacrilatos EndoREZ Adhesive endodontics. Development and usefulness of the methacrylate resin-based endodontic sealer EndoREZ

Resumen Durante la última década se han incorporado al mercado una nueva generación de selladores endodónticos a base de metacrilatos hidrófilos, los que permiten obtener una adhesión efectiva a las paredes dentinarias y a los conos estandarizados provistos por el fabricante. El objetivo de este trabajo es informar acerca de las propiedades, características específicas y utilidades del sellador a base de metacrilatos EndoREZ. Las investigaciones relacionadas con su capacidad de sellado, biocompatibilidad y aplicación clínica sugieren que el EndoREZ es un material potencialmente efectivo para su uso clínico, y que su perfomance puede equipararse a la de los selladores endodónticos tradicionales. Palabras clave: Biocompatibilidad, endodoncia, EndoREZ, sellado apical. Abstract During the last decade a new generation of methacrylate resinbased endodontic sealers, has gained popularity for root canal obturation. These new sealers allow for effective adhesion/adaptation to the root canal walls and to several specially formulated cones. The aim of this article is to report on the properties and usefulness of a methacrylate resin-based sealer EndoREZ. Laboratory and clinical investigations have demonstrated that EndoREZ is effective as a root canal sealer and that its clinical performance is comparable to what had been reported in the literature for other traditional endodontic sealers. Key words: Biocompatibility, endodontic treatment, EndoREZ, apical seal