Roberto Markarian

ImplArt Dental Clinic

Purpose: To measure the microgap between dental implants and custom abutments fabricated using different computer-aided design/computer-aided manufacture (CAD/CAM) methods before and after mechanical cycling. Materials and Methods: CAD software (Dental System, 3Shape) was used to design a custom abutment for a single-unit, screw-retained crown comp...

Purpose: Intraoral scanning subgingival finish lines has been described as challenging. The purpose of this study was to assess the impact of gingival contour around margins of implant stock abutments on marginal fit of Computer-aided Design - Computer-aided Manufacturing (CAD-CAM) zirconia copings. This in-vitro study was conducted on 40 analogue...

Aim: To perform a scoped literature review on advantages of digital workflows in dentistry that could be widely adopted to address safety issues raised during the coronavirus (COVID-19) pandemic. Methods: Recent studies on any advantages of digital dentistry – as compared to conventional methods – that could help addressing the new safety demands f...

Statement of problem Computer-aided design and computer-aided manufacturing (CAD-CAM) methodologies allow the fabrication of custom dental implant abutments with a variety of materials and techniques. Studies on the mechanical strength of such components and the wear induced at their coupling interface during mechanical cycling are sparse. Purpose...

Purpose: To compare the marginal fit and internal surface roughness of CAD/CAM zirconia copings milled with 3- and 5-axis milling devices. Materials and methods: Forty titanium implant stock abutments (4.8 mm in diameter, 4 mm in height) screwed to dental implants (4.1 mm in diameter) embedded in resin were considered phantoms and included in th...

Purpose: Low-cost resin 3D printers have been used to produce affordable interim single crowns in public and private dental practices. The purpose of this study was to assess the impact of different computer-aided design (CAD) software programs on 3D trueness, microscopic marginal and internal gaps, time to design, and interproximal contacts of lo...

Aim: There is controversy in the literature regarding clinical outcomes of CAD/CAM laminate veneers. The aim of the present study was to assess the impact of different levels of CAD expertise and different software programs on the reliability and reproducibility of digital wax patterns of laminate veneers and single crowns. Materials and methods:...

Purpose: To compare the accuracy of dentists with different levels of expertise in computer-aided design (CAD) and prosthodontics to digitally design single crowns. Material and methods: This in vitro study was conducted on 12 prepared teeth in 2 reference dental study models. The models were scanned using an intraoral scanner. Four dentists wit...

Computer‐assisted implant surgeries have revolutionized modern implantology, optimizing final results. This chapter presents a step‐by‐step guide and research evidence on digital workflow in implant dentistry. Currently, two main methods are available for obtaining orientation of the ideal three‐dimensional positioning of dental implants during the...

This chapter presents a history of the use of CAD‐CAM in dentistry in the last two decades, and the basic knowledge required plus ideas and alternatives to start with digital dentistry. In order to become familiar with digital dentistry and take advantage of its benefits, it is required to learn a series of important concepts and abbreviations. The...

This chapter covers the main digital workflow techniques currently used in the field of prosthodontics and restorative dentistry. Dental technologists who become computer‐aided design (CAD) technicians can usually also help to integrating the different steps of digital restorative dentistry. Intraoral scanning can be limited by mouth opening, size...

The purpose of this in-vitro study was to compare trueness, 3D deviation, production time and costs of milled and 3D-printed resin single crowns. A total of 20 CAD-CAM resin single crowns were fabricated from 10 digital wax patterns designed on 10 tooth preparations available in a reference model. Standardized control linear measurements were perfo...

Statement of problem The digital waxing of single crowns can be affected by the quality of intraoral scans and use of computer-aided design (CAD) software programs. However, clinical outcomes of the resulting crowns are also affected by computer-aided manufacturing (CAM) methodologies. Studies on the effect of different levels of expertise on digit...

Key Clinical Message The use of an intraoral scanner was efficient to produce a full‐contour zirconia CAFIP, with improved esthetics when compared to the original prosthesis.

Objetivo: Medir o microespaço entre implantes dentários e pilares personalizados fabricados utilizando diferentes métodos de desenho e fabricação assistidos por computador (CAD/CAM) antes e após ciclagem mecânica. Materiais e Métodos: O software CAD (Dental System, 3Shape) foi usado para projetar um pilar personalizado para uma coroa unitária, apar...

The use of ceramic frameworks and abutments has become popular in tooth- or implant-supported oral rehabilitations. The aim of this study was to evaluate the margin fi t of a CAD/CAM generated, external hex zirconia abutment. For this, ten zirconia abutments (test group) were obtained from scanning of a 4.1mm implant replica. Ten titanium abutments...

The all-on4 protocol has been proposed for the rehabilitation of edentulous arches with immediate load. It consists on the insertion of four implants in the maxilla or the mandible. The more distal implants are 30 degrees angled, and a fully resin prostheses is installed over the implants. The objective of this work was to evaluate in three patient...

The objective of this work was to compare by photoelastic analysis the stress distribution along a fixed framework placed over angled or parallel implants with different gap values between the framework and one of the implants. Two photoelastic models were created: (i) with parallel implants; (ii) with a 30 degrees angled central implant. In both c...

Summary A collaboration project between the School of Dentistry and the Institute of Physics of the University of São Paulo has been established to measure elemental concentrations in teeth by proton induced X-ray emission (PIXE) and heavy ion elastic recoil detection analysis (HI-ERDA) techniques. Data on trace elements in human, bovine and swine...

Changes of elementary concentrations in dental enamel after a bleaching treatment with different products, is presented, with special focus on the oxygen contribution. Concentrations for Ca, P, O and C and some other trace elements were obtained for enamel of bovine incisor teeth by HI-ERDA measurements using a 35Cl incident beam and an ionization...

Animal teeth are routinely used in studies that test dental materials; however, no studies have yet proposed the use of swine teeth in laboratory tests. The purpose of this study was to compare the effects of acid etching on the dentine and enamel of human and swine teeth, aiming at the use of swine teeth as substitutes for human teeth in adhesion...

It is believed that the occlusal covering with less rigid materials, such as acrylic resins could reduce load transfer to the bone. The purpose of this research is to compare, by photoelastic and dynamic analysis, the load transfer to single implants, varying the occlusal materials. A photoelastic model was created, with an anatomy similar to a man...

Human, bovine and swine teeth were analyzed by Proton Induced X-ray Emission (PIXE). The aim of this work was to determine the concentration of trace elements in enamel and dentine of different animal species. PIXE analysis was carried out at the Laboratório de Análise de Materiais por Feixes Iônicos da USP (LAMFI) using a 2.4 MeV proton beam to pr...

BIOMECÂNICA DA TRANSMISSÃO DE CARGAS A IMPLANTES UNITÁRIOS EM FUNÇÃO DOS MATERIAIS PROTÉTICOS - ANÁLISE FOTOELÁSTICA E DINÂMICA. Less rigid oclusal materials such as acrylic resins are often used in prosthesis over implants because they are supposed to diminish the loads transferred to the bone; however there is no scientific evidence to support th...

The longevity of implant-supported prosthetic rehabilitation depends largely on how the masticatory forces are transferred to the implants and surrounding bone. Anatomical conditions, bone morphology and aesthetics usually dictate implant placement in less than ideal positions for prosthetic rehabilitation and sometimes it is possible to find them...

An external PIGE–PIXE setup was installed on a beam line of the 8 MV tandem Pelletron accelerator of the Open Nuclear Physics Laboratory (LAFN). Proton beam energy was chosen in the 8–12 MeV range, sufficient to get an acceptable gamma ray yield but not so high as to prevent us from measuring X-rays. This also allowed the use of a thick aluminum ex...

Gallium-based dental alloys were created with the aim of solving the problem of toxicity of mercury. The material shows mechanical properties similar to those of dental amalgam, but researches point out two unfavorable characteristics: great corrosion and excessive post-setting expansion, and the latter is capable of cracking dental structures. The...