View clinical trials related to Crowns.
Filter by:The use of rubber dam when performing adhesive restorations improves the quality of the treatment. The widespread use of this type of restorations makes it increasingly necessary to use this type of isolation of the operative field. At the same time, the use of CAD/CAM systems in dentistry has recently become more widespread, which means that chairside systems are being used more and more frequently. Given that in indirect restorations it is necessary to place the rubber dam at the time of cementation, it has been proposed to take optical impressions of the preparation with the rubber dam already in place. For this it is necessary to have previous records that are cut out and rescanned. Since there are authors who have described that rescanning can cause defects in the meshes, in this work we try to compare both types of scanning in a specific type of restorations, the overlays. For this purpose, scans of the tooth preparation with and without rubber dam are taken, and a random decision is made on the basis of which scan the restoration is made. Then it is taken to the mouth and the marginal fit, contact points and occlusion of the restoration are evaluated. The results of the group made from the scan without dam are compared with those of the group made from the scan with dam. The two scans of each case are also compared to evaluate the differences.
Regardless of the fabrication workflow occlusal adjustments seem to be inevitable during delivery of indirect fabrication of the restoration. This has been attributed to snowballing of discrepancies due to multiple procedures for information transfer between the clinician and the laboratory. Current digital workflows minimize these discrepancies due to digital acquisition technology which eliminates drawbacks from physical materials which would alter the dimensions and morphology of the final restoration. Utilizing 3D face scanning technology is by far the least invasive and the least time consuming of available virtual facebow techniques and thus it's utilization could offer the benefit of saving time during occlusal adjustment and enhanced strength of the restoration by not subjecting it to the heat generation and subsequent crack initiation which occurs during occlusal adjustment. This study aims to compare the effect of a face scan to alignment of the maxillary cast on the volume and time of occlusal adjustment compared to conventional articulator digitization to align the maxillary cast.
The purpose of this study is to investigate the use of an all-ceramic dental crown material to restore the abutment teeth of partially-edentulous patients who need removable partial dentures (RPD). The outcomes of the treatment group (all-ceramic crowns) will be compared to a similarly-treated control group whose RPD abutment teeth are restored using conventional metal and metal-ceramic crowns. Primary outcomes of interest include crown survival, abutment tooth survival and RPD survival.The null hypothesis is that at the conclusion of the study there will be no differences in outcomes between the two groups. All dental treatment, including dental hygiene and periodontal care, fillings, crowns and RPD fabrication will be provided by predoctoral dental students in the University of Kentucky College of Dentistry student clinics. Students treating the subjects will be supervised by licensed, technique-calibrated faculty specialists. Following the completion of dental treatment, enrolled subjects will be clinically re-evaluated by investigators at 6 months, and at annual intervals thereafter for 5 years following RPD delivery.