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Purpose: To evaluate the influence of implant scanbody (ISB) material, position and operator on the accuracy of a confocal microscopy intraoral scanning (IOS) for complete-arch implant impression., Methods: An edentulous maxillary model with 6 internal hexagonal connection analogues was scanned with an extraoral optical scanner to achieve a reference file. Three ISBs made of different materials (polyetheretherketone (Pk), titanium (T) and Pk with a titanium base (Pkt)) were scanned with IOS by 3 operators. The resulting 45 test files were aligned to the reference file with a best fit algorithm. Linear (ΔX, ΔY and ΔZ-axis) and angular deviations (ΔANGLE) were assessed. Absolute values of the linear discrepancies were summed up to obtain a global measure of linear absolute error (ΔASS). Influence of ISB material, position and operator was statistically assessed using the mixed general linear model., Results: At multivariate analysis, whenΔASS was considered as response variable, it was identified a significant influence of material (p<0.0001) and position (p=0.0009) while no significant operator effect was detected. When ΔANGLE was considered as response variable, material and position significantly influenced the expected ΔANGLE (p=0.0232 and p<0.0001) and no operator effect was identified., Conclusions: The investigated IOS for complete-arch digital impression was influenced by the ISB material with peek reporting the best results on both linear and angular measurements followed by titanium, peek-titanium resulting as the less accurate. Implant angulation affected significantly the linear deviations while implant position the angular deviations. Operator did not show any significant effect on the IOS accuracy., (Copyright © 2019 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.)

The aim of this review was to collect available evidence and evaluate accuracy outcomes of dental implant impression techniques, and to compare the accuracy of conventional implant impression versus digital implant impression. Inclusion and exclusion criteria were defined by the authors before the start of the study. The inclusion criteria were: all studies published in English language; studies no older than five years; analyzing the accuracy of digital vs conventional technique impression on implants. The exclusion criteria were: publications that reported the same data as later publications by the same authors and systematic reviews; commentaries and letters to the editor; case report and case series. The search resulted in 106 titles. Following the first stage of screening, after the records identification through database manual searching, 112 potentially relevant studies were identified. After the second stage screening, 33 full text publications were obtained and analyzed and 17 were excluded. Afterwards, 18 articles resulted eligible after full text reading and a cross search of the articles' references was accomplished; 3 articles were consequently added. At the end only 7 articles were included in the quantitative analysis. Within the limitations of this systematic review, digital impression on dental implants offers a comparable accuracy compared with conventional impressions technique. More clinical trials are recommended to investigate the accuracy of these scanners and their validity in clinical use., (Copyright 2020 Biolife Sas. www.biolifesas.org.)

The purpose of this study is to evaluate the influence of implant scanbody (ISB) material and operator on scanning fluency and polygonal mesh numbers of a confocal microscopy intraoral scanning (IOS). An edentulous maxillary master model with 6 implant analogues was assembled. Thereafter 3 ISBs featured with same geometry but different materials (polyetheretherketone (PK), titanium (T) and PK with a titanium base (PKT)) were produce and scanned according to a randomized sequence by three different operators. The confocal microscopy IOS resulted in 45 STL test files that were processed to a dedicate software to obtain the request data. The overall analysis of fluency (imm/sec) showed the following results: mean 11.997 imm/sec, SD 2.355. The multivariate analysis showed statistical significance of material (p<.0001) and operator (p<.0001) influence. The univariate analysis referred to polygonal mesh numbers expressed the following results: mean 30327.8, SD 2432.5. The multivariate analysis stressed how there is a related effect to materials (p<.0001) and operator (p=0.0205). PKT represented the material with the best results for both. Analyzing the overall distribution histogram for scanning fluency, the IOS device seems to work with higher frequency at level of 13 imm/sec. The distribution of the measurements in the reference histograms showed an effect related to both variables referring to scanning fluency as well as to polygonal mesh numbers. Operator can be considered as a random effect; regarding the materials, the difference between PKT and PK can be related to the different base material. The dissimilar optical properties of T justify the different behavior., (Copyright 2020 Biolife Sas. www.biolifesas.org.)

The aim of this study was to compare the fit of all-ceramic restorations on natural teeth fabricated through a direct digital workflow or an indirect digital workflow. An electronic search of publications was established from three electronic databases: Cochrane, PubMed and Web of Science. The search strategy used a combination of controlled vocabulary and free-text words. The detailed search design and strategies, including keywords, are presented below. The authors used two filters to follow data for the research: papers written in English and published in the last 5 years. The search resulted in 3042 titles. Following the first stage of screening, after the records identification through database manual searching, 3047 potentially relevant studies were identified. After the second stage screening, 38 full text publications were obtained and analyzed and 17 were excluded. Afterwards, 22 articles resulted eligible after full text reading and a cross search of the articles references was accomplished and 5 articles were consequently added. At last, 6 articles were included in the quantitative analysis. This study was designed to compare the fit of restorations obtained by means of a direct or indirect digital workflow. The values reported on the maximum acceptable gap in scientific literature range from 50 to 200 μm, so there does not seem to be an objective limit based on scientific evidence. According to the most accepted marginal discrepancy in the literature, most of the values of the studies examined are in the 200 μm acceptability range. Within the limitations of this systematic review, computer-aided design and computer-aided manufacturing (CAD/CAM) fabricated restorations obtained by means of an intraoral scanner (IOS) showed better marginal and internal fit than restorations obtained through conventional impression and subsequent laboratory scanning. According to the results of this systematic review, the direct digital workflow resulted as a valid alternative to the indirect digital workflow to produce CAD/CAM all-ceramic restorations., (Copyright 2019 Biolife Sas. www.biolifesas.org.)

Nowadays, an increasing number of dentists are using intraoral scanners (IOS) in their daily practice as an alternative to conventional impression taking. One of the main concerns is related to the capability of scanning the subgingival anatomy of the die, usually very challenging due to the limited operative field and the presence of oral fluids. The radiosurgery assisted gingival displacement technique (RAGD) may enhance the intraoral optical scanning of the finish line and neighbor tooth anatomy. The contour of the interim prosthesis is used to drive the tip of radiosurgery electrode along the tooth surface and open selectively the gingival crevice with a prosthetically-driven and minimally invasive approach. The clinical implication of this technique is related to increasing the efficiency and accuracy of the digital impression technique in the critical zone of the prosthetic shoulder.