To overcome difficulties associated with conventional techniques, impressions with IOS (intraoral scanner) and CAD/CAM (computer-aided design and manufacturing) technologies were developed for dental practice. The last decade has seen an increasing number of optical IOS devices, and these are based on different technologies; the choice of which may impact on clinical use. To allow informed choice before purchasing or renewing an IOS, this article summarizes first the technologies currently used (light projection, distance object determination, and reconstruction). In the second section, the clinical considerations of each strategy such as handling, learning curve, powdering, scanning paths, tracking, and mesh quality are discussed. The last section is dedicated to the accuracy of files and of the intermaxillary relationship registered with IOS as the rendering of files in the graphical user interface is often misleading. This overview leads to the conclusion that the current IOS is adapted for a common practice, although differences exist between the technologies employed. An important aspect highlighted in this review is the reduction in the volume of hardware which has led to an increase in the importance of software-based technologies.

No abstract

Statement of problem.Different parameters can influence the adaptation of computer-aided design and computer-aided manufacturing (CAD-CAM) inlay/onlay restorations. However, systematic reviews to identify and discuss these parameters are lacking.Purpose. The purpose of this systematic review was to summarize the scientific literature investigating all parameters that can influence both the marginal and internal adaptation of CAD-CAM inlay/onlay restorations.Material and methods. An electronic search was conducted by 2 independent reviewers for studies published in English between January 1, 2007 and September 20, 2017 on the PubMed/Medline, Scopus, and Web of Science databases and in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Factors investigated in the selected articles included the type of CAD-CAM system, virtual space parameters, version of the software, type of block, luting procedure, type of restoration, sample size and aging procedure, evaluation method, and number of measurement points per specimen.Results. A total of 162 articles were identified, of which 23 met the inclusion criteria. Nine studies investigated adaptation with different restorative materials, 2 evaluated adaptation according to the type of preparation design, 9 compared adaptation before/after

Purpose To investigate the relationship between the microstructure of CAD/CAM blocks and the quality of adhesion as function of the surface treatment and resin cement type. Materials and methods Two nano‐ceramic composite resin CAD/CAM blocks, Lava Ultimate (LU) and Cerasmart (CS), and two Leucite‐reinforced glass ceramic CAD/CAM IPS blocks, Empress® CAD (EM) and InitialTM LRF (IR), received either Hydrofluoric acid (HF) or sandblasting (SB) surface treatments. The blocks were then luted using two dual‐cure resin cements, LinkForce (LF) and Multilink Automix (ML) with their corresponding silanes, resulting in 16 study groups. The luted blocks were then thermal‐cycling (TC) for 5000 cycles and subjected to a microtensile bond strength (μTBS) test. Scanning electron microscopy (SEM) micrographs of the treated surfaces were analyzed using ImageJ software and XRD analyses were performed for the two ceramic blocks. The data obtained were submitted to Games‐Howell post‐hoc nonparametric test to compare combinations of groups or treatments and a linear mixed‐effects model for the factors surface treatment, block type, and resin cement, together with their first‐degree interactions (α = 0.05). Results The lowest mean μTBS values were obtained with LU‐HF, whereas the highest mean μTBS values were obtained with CS regardless of resin cement type and surface treatment method. IR‐HF mean μTBS were significantly higher than IR‐SB, EM‐SB, and EM‐HF. Analysis using ImageJ software demonstrated significant differences in the density and pore size after HF surface treatment. Conclusions The specific microstructure of each block material within the same family group impacted the micromechanical retention and the bonded interface strength.