A new classification system for the restoration of root filled teeth.

The aim of this report is to (i) review the current literature on the status of root filled teeth, (ii) analyse the most important factors in decision-making, (iii) discuss the current restorative concepts, and (iv) classify both the evidence and clinical practice in a way that seeks to be clear, understandable and helpful for clinicians. Restoration of root filled teeth represents a challenge for the clinician and remains a controversial subject. The guidelines describe a new classification that is drawn from evidence presented in the literature and also from clinical expertise-based reviews. It describes five categories of teeth.

Composite vs ceramic computer-aided design/computer-assisted manufacturing crowns in endodontically treated teeth: analysis of marginal adaptation.

OBJECTIVES: To compare the marginal adaptation between ceramic and composite CEREC crowns in endodontically treated teeth restored with endocrowns or with a short or a long post. METHODOLOGY: Forty-eight intact maxillary incisors were used. After endodontic treatment, the crowns were sectioned 2 mm coronally to the cemento-enamel junction, which provided a ferrule of 2 mm. The prepared teeth were divided randomly into six groups (n=8). Group 1 was restored with a large fiberglass post, composite core, and ceramic full-coverage computer-aided design/computer-assisted manufacturing (CAD-CAM) crown. Group 2 was restored with a short fiberglass post, composite core, and ceramic full-coverage CAD-CAM crown. Group 3 was restored with a large fiberglass post, composite core, and composite full-coverage CAD-CAM crown (LPCpr). Group 4 was restored with a short fiberglass post, composite core, and composite full-coverage CAD-CAM crown (SPCpr). Groups 5 and 6 were restored with ceramic and composite CEREC machined endocrowns, respectively (EndoCer and EndoCpr). The restored teeth were loaded thermomechanically in a computer-controlled chewing machine. Impressions of each restoration were made in a polyvinylsiloxane material before and after loading. Gold-coated epoxy replicas were prepared for scanning electron microscopy examination at 200× magnification. RESULTS: Loading had a statistically significant effect (p<0.05) on the percentage of "continuous margin" in all groups. The LPCpr, SPCpr, and EndoCpr groups showed the highest percentage of continuous margin initially and after loading. The effect of the different post lengths on marginal adaptation was not significant (p>0.05). CONCLUSION: CAD-CAM crowns fabricated from millable composite resin blocks (Paradigm MZ100) offer a superior option to all-ceramic crowns (IPS Empress CAD).

Performance tests of two portable mini gamma cameras for medical applications.

We have developed two prototypes of portable gamma cameras for medical applications based on a previous prototype designed and tested by our group. These cameras use a CsI(Na) continuous scintillation crystal coupled to the new flat-panel-type multianode position-sensitive photomultiplier tube, H8500 from Hamamatsu Photonics. One of the prototypes, mainly intended for intrasurgical use, has a field of view of 44 x 44 mm2, and weighs 1.2 kg. Its intrinsic resolution is better than 1.5 mm and its energy resolution is about 13% at 140 keV. The second prototype, mainly intended for osteological, renal, mammary, and endocrine (thyroid, parathyroid, and suprarenal) scintigraphies, weighs a total of 2 kg. Its average spatial resolution is 2 mm; it has a field of view of 95 x 95 mm2, with an energy resolution of about 15% at 140 keV. The main advantages of these gamma camera prototypes with respect to those previously reported in the literature are high portability and low weight, with no significant loss of sensitivity and spatial resolution. All the electronic components are packed inside the mini gamma cameras, and no external electronic devices are required. The cameras are only connected through the universal serial bus port to a portable PC. In this paper, we present the design of the cameras and describe the procedures that have led us to choose their configuration together with the most important performance features of the cameras. For one of the prototypes, clinical tests on melanoma patients are presented and images are compared with those obtained with a conventional camera.

Design and tests of a portable mini gamma camera.

Design optimization, manufacturing, and tests, both laboratory and clinical, of a portable gamma camera for medical applications are presented. This camera, based on a continuous scintillation crystal and a position-sensitive photomultiplier tube, has an intrinsic spatial resolution of approximately 2 mm, an energy resolution of 13% at 140 keV, and linearities of 0.28 mm (absolute) and 0.15 mm (differential), with a useful field of view of 4.6 cm diameter. Our camera can image small organs with high efficiency and so it can address the demand for devices of specific clinical applications like thyroid and sentinel node scintigraphy as well as scintimammography and radio-guided surgery. The main advantages of the gamma camera with respect to those previously reported in the literature are high portability, low cost, and weight (2 kg), with no significant loss of sensitivity and spatial resolution. All the electronic components are packed inside the minigamma camera, and no external electronic devices are required. The camera is only connected through the universal serial bus port to a portable personal computer (PC), where a specific software allows to control both the camera parameters and the measuring process, by displaying on the PC the acquired image on "real time." In this article, we present the camera and describe the procedures that have led us to choose its configuration. Laboratory and clinical tests are presented together with diagnostic capabilities of the gamma camera.