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

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

Changes to the 8th Edition AJCC: Staging Head and Neck Cancer

In this presentation, selected topics from the changes in the 8th edition of the American Joint Committee on Cancer (AJCC) staging system for head and neck tumors will be discussed

Imaging of the Infrahyoid Neck: Systematic Approach

In this presentation a systemic approach to infrahyoid neck imaging analysis is presented based on five individual spaces: the visceral, carotid, retropharyngeal, posterior cervical and perivertebral space. These spaces are defined by the three layers of the Deep Cervical Fascia (DCF). Each space has its own specific anatomical ‘contents’. Therefore, once a disease process is assigned to one space, it is usually possible to formulate a short differential diagnosis based on the anatomy present in that space

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

The potential impact of CT-MRI matching on tumor volume delineation in advanced head and neck cancer

To study the potential impact of the combined use of CT and MRI scans on the Gross Tumor Volume (GTV) estimation and interobserver variation. Four observers outlined the GTV in six patients with advanced head and neck cancer on CT, axial MRI, and coronal or sagittal MRI. The MRI scans were subsequently matched to the CT scan. The interobserver and interscan set variation were assessed in three dimensions. The mean CT derived volume was a factor of 1.3 larger than the mean axial MRI volume. The range in volumes was larger for the CT than for the axial MRI volumes in five of the six cases. The ratio of the scan set common (i.e., the volume common to all GTVs) and the scan set encompassing volume (i.e., the smallest volume encompassing all GTVs) was closer to one in MRI (0.3-0.6) than in CT (0.1-0.5). The rest volumes (i.e., the volume defined by one observer as GTV in one data set but not in the other data set) were never zero for CT vs. MRI nor for MRI vs. CT. In two cases the craniocaudal border was poorly recognized on the axial MRI but could be delineated with a good agreement between the observers in the coronal/sagittal MRI. MRI-derived GTVs are smaller and have less interobserver variation than CT-derived GTVs. CT and MRI are complementary in delineating the GTV. A coronal or sagittal MRI adds to a better GTV definition in the craniocaudal directio

Tumour thickness in oral cancer using an intra-oral ultrasound probe

To investigate tumour-thickness measurement with an intra-operative ultrasound (US) probe. A retrospective data analysis was undertaken for a total of 65 patients with a T1-2 oral cavity cancer, who were seen at a tertiary referral centre between 2004 and 2010. The correspondence between tumour thickness measured by ultrasonography and histopathology was assessed by Pearson's correlation coefficient, and also between tumour thickness and the development of neck metastasis. In 11 cases, intra-oral measurement was not optimal due to limited mouth opening (n = 2) or impossibility to depict the lesion (n = 9). Tumour thickness measured by US correlated well with histopathology (n = 23, R = 0.93). Tumour thickness of a parts per thousand currency sign7 mm carries a risk of lymph node metastasis of 12%, whereas in tumours exceeding 7 mm this risk is 57% (p = 0.001). Twenty-five percent developed neck metastasis and 19% had local recurrence. Tumour thickness is an important predictive marker for lymph node metastases. As such, it can help in decision-making with regard to management of the primary tumour and neck. Based upon our findings, a wait-and-see policy is only warranted for superficial lesions with tumour thickness of less than 7 mm, but only if regular follow-up using US-guided aspiration of the neck is ensure