An Innovative Treatment Approach Using Digital Workflow and CAD-CAM Part 2: The Restoration of Molar Incisor Hypomineralization in Children.
ABSTRACT: Until recently, the treatment for molar incisor hypomineralization (MIH) mainly included interim restorations such as resin restorations and stainless-steel crowns. These require replacement after adolescence. The use of intraoral scanners (IOS) has opened a new venue for restoring MIH teeth, by reducing the challenge of dealing with uncooperative children's behavior and enabling tooth structure preservation and long-lasting restoration. We present an innovative treatment approach for children with MIH, using a digital workflow with IOS and CAD-CAM (computer-aided design and computer-aided manufacturing) fabrication of the restoration. The overall protocol involves a thorough diagnostic phase throughout treatment planning, which takes into consideration the child's behavior and the parent's cooperation and compliance. Initial preparation consists of inhalation sedation if needed, an effective local anesthesia, and the use of a rubber dam. Removal of all areas of enamel and dentin porosity is essential, and the tooth/teeth must be appropriately prepared to accommodate inlays or onlays for molars and labial veneers for incisors. IOS impressions are taken, including scanning of the prepared tooth and its antagonist, scanning of the bite, and CAD-CAM preparation of the restoration. Next is restoration, cementation, and follow up. Digital workflow provides definitive restorations in young patients due to the high accuracy of the scanning.
Project description:Stainless steel crowns are the most popular restoration technique for young permanent first molars treated endodontically. However, these restorations are not aesthetically appealing and need to be replaced. Endocrowns constitute a reliable approach for restoring severely damaged molars and premolars. Intraoral scanners (IOSs) are well tolerated by children and are easily and quickly implemented. We present an innovative treatment approach for endodontically treated teeth in children, using a digital workflow with IOS and computer-aided design/computer-assisted manufacturing (CAD/CAM) fabrication of the restoration. The protocol involves a thorough diagnostic phase and comprehensive treatment planning. Among the factors to be considered are the child's behavior, the parents' cooperation and compliance, and initial preparation including inhalation sedation, effective local anaesthesia and the use of a rubber dam. Full attention should be given to 1-2 mm of ferruling by the endocrown, which should be appropriately prepared to accommodate endocrowns for molars. IOSs include scanning of the prepared tooth and its antagonist, and scanning of the bite. CAD-CAM preparation of the restoration is followed by restoration bonding and follow up. Digital workflow should be considered in the treatment of endodontically treated molars since the high accuracy of the scanning enables definitive restoration in young patients.
Project description:Computer-aided design/computer-aided manufacturing (CAD/CAM) technology was developed to ensure the sufficient strength of tooth restorations, to improve esthetic restorations with a natural appearance and to make the techniques easier, faster and more accurate. In the view of the limited research on the surface treatments of the CAD/CAM materials and the need to evaluate the ideal surface characteristics of a material to achieve the best adhesion to tooth tissues, this study aimed to investigate the surface roughness and morphology of four different CAD/CAM materials using four different surface treatments. The CAD/CAM materials used in this study were three composites (Shofu Block HC, Lava Ultimate and Brilliant Crios) and a hybrid ceramic (Enamic). The surface of the specimens of each material received one of the following treatments: no surface treatment, sandblasting with 29 ?m Al2O3 particles, 9% hydrofluoric acid etching and silane application, and the tribochemical method using CoJet System. Surface roughness was evaluated using optical profilometry, and surface morphology was observed by means of scanning electron microscopy. All surface treatments resulted in higher surface roughness values compared to the control group. Different treatments affected the surface properties of the materials, presumably due to discrepancies in their composition and structure.
Project description:<h4>Objectives</h4>The purpose of this randomized clinical trial was to compare the required time of potential clinical adjustments of posterior screw-retained monolithic zirconia implant retained crowns based on intraoral optical scanning (IOS) or conventional impressions.<h4>Materials and methods</h4>Patients with posterior tissue level implants (Straumann RN) replacing solitary teeth were recruited. Of all patients, impressions were taken with both an IOS (3M<sup>™</sup> TDS) and a conventional (polyether) pick-up impression. Randomization was performed after impression taking and patients were to receive either a crown based on the digital or the conventional impression. The time required for adjustments at placement was recorded. Additionally, restoration survival and mechanical complications with a follow-up of one year were documented.<h4>Results</h4>Thirty two patients with 45 implants were included: 23 restorations in the test (IOS) and 22 in the control (conventional) group. The average adjustment time was 3.35 min (SD ± 3.38, range: 0-11 min) for the digital versus 6.09 min (SD ± 4.63, range: 0-18 min) for the conventional impressions (p = .039). A proper fit (no adjustments required) was achieved 39,1% in the digital and 18,2% conventional group respectively. All 45 restorations could be placed within the two planned appointments and only two minor mechanical complications occurred during the first year of function.<h4>Conclusions</h4>The use of IOS resulted in shorter adjustment times at try-in than conventional impressions for solitary CAD/CAM implant restorations. Screw-retained solitary monolithic zirconia restorations on ti-base abutments show low complication- and survival rates in the short term.
Project description:<h4>Introduction</h4>Computer-aided design and computer-aided manufacturing (CAD/CAM) technology is an innovative digital system capable of scanning prepared teeth that are intended to receive crowns, bridges, and inlays and then effectively designing and fabricating restorations. Many dental schools are currently implementing this innovative CAD/CAM technology as part of their curricula and at University of Florida College of Dentistry we created a hands-on elective.<h4>Methods</h4>The 5-week course requires 2- to 3-hours of time per week for the lectures and labs. The sessions cover an introduction to digital d