In vitro assessment of an intraoral scanner accuracy on abutments with horizontal preparation geometries and subgingival margins.

Objectives: This study evaluated the accuracy of the Medit i700 intraoral scanner (IOS) in capturing horizontal tooth preparations at different depths below the gingival margin and assessed its ability to detect surfaces beyond the finish line.

Methods: Using CAD software, two abutments of a standard maxillary first molar were designed with horizontal preparation and 0.8 mm chamfer at 1 mm and 2 mm depths below the gingival margin.

A 13- to 17-year Retrospective Evaluation of the Clinical Performances of Anterior and Posterior Lithium Disilicate Restorations onto Teeth and Implants.

This retrospective study aimed at evaluating the clinical outcomes of lithium disilicate prostheses onto teeth and implants. A total of 860 restorations were delivered to 312 patients, including crowns, veneers and onlays. Patients with uncontrolled gingival inflammation and/or periodontitis were excluded, whilst subjects with occlusal parafunctions were included.

A randomized controlled clinical trial on press and block lithium disilicate partial crowns: A 4-year recall.

Purpose: To evaluate clinical performances of two lithium disilicate systems (Initial LiSi press vs Initial LiSi Block, GC Co.) using modified United States Public Health Service (USPHS) evaluation criteria and survival rates after 4 years of clinical service.

Methods: Partial adhesive crowns on natural abutment posterior teeth were made on 60 subjects who were randomly divided into two groups: Group 1: Initial LiSi press and Group 2: Initial LiSi Block.

Trueness and precision of an intraoral scanner on abutments with subgingival vertical margins: An in vitro study.

Objectives: This study aimed to evaluate the accuracy of an intraoral scanner (IOS - Medit i700) on tooth abutments with vertical preparations at 2 depths below the free gingival margin, and to determine if the IOS can reproduce the area beyond the finish surface of the tested preparation geometry.

Methods: Two abutments for a maxillary first molar were designed by means of CAD software, with vertical preparations set at 1 and 2 mm below the gingiva. These abutments were subsequently printed in resin and placed on a reference model.

Trueness, precision, time-efficiency and cost analysis of chairside additive and subtractive versus lab-based workflows for manufacturing single crowns: An in vitro study.

Purpose: To evaluate the trueness, precision, time efficiency, and cost of three different workflows for manufacturing single crowns (SCs).

Methods: A plaster model with a prepared tooth (#15) was scanned with an industrial scanner, and an SC was designed in computer-assisted-design (CAD) software. Ten SCs were printed with a hybrid composite (additive chairside) and a stereolithographic (SLA) printer (Dfab®), 10 SCs were milled in lithium disilicate (subtractive chairside) using a chairside milling unit (inLab MC XL®), and 10 SCs were milled in zirconia (lab-based) using a five-axis laboratory machine (DWX-52D®).

Assessment of distortion of intraoral scans of edentulous mandibular arch made with a 2-step scanning strategy: A clinical study.

Statement Of Problem: Manufacturers of several intraoral scanners have recommended a 2-step strategy for scanning the edentulous mandible. The 2-step technique requires scanning one side first and then moving to the other side. However, whether inconsistency in stitching occurs that results in loss of accuracy or distortion is unclear.

Clinical longevity of direct and indirect posterior resin composite restorations: An updated systematic review and meta-analysis.

Objectives: To answer the PICO(S) question: Is there a difference in clinical longevity between direct and indirect resin composite restorations placed on permanent posterior teeth?

Data: Randomized controlled clinical trials (RCTs) investigating direct and indirect resin composite restorations in posterior permanent teeth were considered.

Sources: Several electronic databases were searched, with no language or date restrictions. The revised Cochrane Collaboration's tool for assessing risk of bias (RoB-2) was used to analyze the studies; meta-analyses were run and the certainty of evidence was assessed by the GRADE tool.

Full Digital Workflow for Mandibular Ameloblastoma Management: Showcase for Technical Description.

This is a showcase for technical description of a full digital workflow aimed to reconstruct and prosthetically rehabilitate the mandible after surgical resection. The surgery was performed following a computer-aided design and computer-aided manufacturing (CAD-CAM) guided workflow, using 3D reconstruction of the mandible and the fibula. After 2 years, when the ossification of the flap was reached and verified by a computed tomography (CT) scan, surgery was performed using a two-step implant rehabilitation, with successful outcomes.

Impact of SARS-CoV-2 on dentistry: a review of literature.

Objective: SARS-CoV-2 is a new Coronavirus identified as the cause of Coronavirus disease in 2019 (COVID-19). The epidemic spread in China and beyond its borders, involving 114 countries with more than 5 million dead. On March 11, the WHO declared the spread of SARS-CoV-2 to be a pandemic and encouraged nations to adopt harsh restrictive measures.

Dentin Exposure after Tooth Preparation for Laminate Veneers: A Microscopical Analysis to Evaluate the Influence of Operators' Expertise.

Background: To assess the quantity of dentin exposure detected by 3 operators with different clinical expertise for 2 designs of tooth preparation for laminate veneers: window (WI) and butt joint (BJ). Methods: 20 intact maxillary central incisors were collected and then prepared for laminate veneers to a depth of 0.6 mm, with a cervical mini-chamfer finish line of 0.

Trueness and precision of 3D-printed versus milled monolithic zirconia crowns: An in vitro study.

Purpose: To compare the trueness and precision of 3D-printed versus milled monolithic zirconia crowns (MZCs).

Methods: A model of a maxilla with a prepared premolar was scanned with an industrial scanner (ATOSQ®, Gom) and an MZC was designed in computer-assisted-design (CAD) software (DentalCad®, Exocad). From that standard tessellation language (STL) file, 10 MZCs (test) were 3D-printed with a Lithography-based Ceramic Manufacturing (LCM) printer (CerafabS65®, Lithoz) and 10 MZCs (control) were milled using a 5-axis machine (DWX-52D®, DGShape).

Optical behaviors, surface treatment, adhesion, and clinical indications of zirconia-reinforced lithium silicate (ZLS): A narrative review.

Objectives: The present narrative review was focused on the optical properties, surface treatment, adhesion, and clinical indications of zirconia-reinforced lithium silicate ceramics (ZLS) for Computer-aided design / Computer-aided manufacturing (CAD/CAM) technologies.

Data/sources: A literature search was performed by 3 calibrated independent researchers on PubMed, Scopus, Embase, Google Scholar, Dynamed, and Open Grey. The criteria for inclusion were: 1) papers addressing at least one of the following variables about ZLS: optical properties, surface treatment, adhesion, and clinical indications; 2) in vitro, in silico, or in vivo studies; 3) case reports; 4) systematic reviews.

Zirconia-reinforced lithium silicate (ZLS) mechanical and biological properties: A literature review.

Objectives: This paper aimed to provide a literature review of the mechanical and biological properties of zirconia-reinforced lithium silicate glass-ceramics (ZLS) in Computer-aided design / Computer-aided manufacturing (CAD/CAM) systems.

Data/sources: An extensive search of the literature for papers related to ZLS was made on the databases of PubMed/Medline, Scopus, Embase, Google Scholar, Dynamed, and Open Grey. The papers were selected by 3 independent calibrated reviewers.

Analysis of The Reproducibility of Subgingival Vertical Margins Using Intraoral Optical Scanning (IOS): A Randomized Controlled Pilot Trial.

Background: The aim of this randomized controlled trial was to evaluate the capability of an IOS (Intra Oral Scanner) device, used in standardized conditions, to detect margins of abutments prepared with knife-edge finishing line located at three different levels in relation to the gingival sulcus.

Methods: sixty abutment teeth for treatment with full crowns were selected and randomly divided in three groups accordingly to the depth of the finishing line: Group A: supragingival margin; Group B: 0.5-1.

Fourteen-year evaluation of posterior zirconia-based three-unit fixed dental prostheses: A Prospective clinical study of all ceramic prosthesis.

Objectives: the purpose of the present prospective trial was to evaluate the clinical performance of posterior 3-unit zirconia-based fixed dental prostheses (FDPs) after 14 years of clinical function.

Methods: thirty-seven patients needing to replace either premolars or molars were involved and 48 FDPs were fabricated (Procera Zirconia, Nobel Biocare AB). Frameworks with a9 mm cross section of the connectors and 0.

Accuracy of Three Impression Materials on the Totally Edentulous Maxilla: In Vitro/In Silico Comparative Analysis.

Background: This study was aimed at comparing the accuracy of impressions of a reference typodont (RT) reproducing a totally edentulous maxilla made with three impression materials: polysulfide, polyether, and polyvinyl-siloxane.

Methods: The RT was scanned using a desktop scanner, obtaining a reference scan. Ten impressions for each of the three tested materials were made using a mechanical device with a standardized and consistent modality.

Mechanical behavior of conceptual posterior dental crowns with functional elasticity gradient.

Purpose: To evaluate the biomechanical behavior of monolithic ceramic crowns with functional elasticity gradient.

Methods: Using a CAD software, a lower molar received a full-crown preparation (1.5 mm occlusal and axial reduction).

Current status on lithium disilicate and zirconia: a narrative review.

Background: The introduction of the new generation of particle-filled and high strength ceramics, hybrid composites and technopolymers in the last decade has offered an extensive palette of dental materials broadening the clinical indications in fixed prosthodontics, in the light of minimally invasive dentistry dictates. Moreover, last years have seen a dramatic increase in the patients' demand for non-metallic materials, sometimes induced by metal-phobia or alleged allergies. Therefore, the attention of scientific research has been progressively focusing on such materials, particularly on lithium disilicate and zirconia, in order to shed light on properties, indications and limitations of the new protagonists of the prosthetic scene.

Effects of Finish Line Design and Fatigue Cyclic Loading on Phase Transformation of Zirconia Dental Ceramics: A Qualitative Micro-Raman Spectroscopic Analysis.

Objectives: Stresses produced during the fabrication of copings and by chewing activity can induce a tetragonal-to-monoclinic (t⁻m) transformation of zirconia. As a consequence, in the m-phase, the material is not able to hinder possible cracks by the favorable mechanism known as "transformation toughening". This study aimed at evaluating if different marginal preparations of zirconia copings can cause a premature phase transformation immediately after manufacturing milling and after chewing simulation.

Posterior partial crowns out of lithium disilicate (LS2) with or without posts: A randomized controlled prospective clinical trial with a 3-year follow up.

Objectives: The objective of this randomized controlled trial was to assess the influence of use of posts as well as the type of posterior tooth (premolars vs molars) for the treatment with lithium disilicate (LS2) partial crowns.

Materials And Methods: A total of 60 patients were treated with posterior LS2 partial crowns. Two groups (n = 60) were made based on the type of restored tooth: Group 1, premolars and Group 2, molars.

Aging resistance, mechanical properties and translucency of different yttria-stabilized zirconia ceramics for monolithic dental crown applications.

Objectives: The dental market moves towards high-translucency monolithic zirconia dental crowns, which are usually placed either with - or without - a thin glaze layer. The microstructural features and the mechanical performances of these materials are still controversial, as well as their susceptibility to aging. This paper aims at studying these aspects in the current generation of zirconia dental crowns showing different degrees of translucency.

The Functional Implant Prosthodontic Score (FIPS): assessment of reproducibility and observer variability.

Objectives: The aim of this study was to validate the reproducibility and observer variability of the Functional Implant Prosthodontic Score (FIPS), while considering the level of dental experience for intra- and inter-examiner analysis.

Materials And Methods: A total of 44 examiners (n = 31 undergraduate dental students and n = 13 postgraduate prosthodontic students) applied FIPS to ten sample cases each showing one implant-supported single crown for premolar or molar replacements. Examiners' assessments were carried out twice at an interval of 2 weeks (round A and round B).