Ronaldo Hirata

• DDS, Ms, PhD
• Professor (Assistant) at New York University College of Dentistry

To evaluate the effect of silanized filler particles and blue light‐sensitive photoinitiator system on the internal and marginal fit of 3D printed resin crowns as well as the volume of provisional cement space. This study evaluated three commercially available 3D‐printing resins (Smart Print Temp/SP, Resilab 3D Temp/RL, and Cosmos Temp/CT). The exp...

Aim: The objective of the present study was to close multiple diastemas. This presents a significant challenge for clinicians, given the esthetic considerations and the need for precise replication of various types of tooth tissue. While direct composite resin layering is a demanding technique, it proves to be a viable approach for reshaping tooth...

Recent advancements in biomimetic dentistry have introduced innovative materials designed to better simulate natural dentin. One such material is Ribbond®, long polyethylene fiber. It is particularly effective in absorbing and redistributing masticatory forces in teeth with substantial dentin loss. This review aims to analyze the literature on the...

Objective: To evaluate color masking and relative translucency parameter (RTP) of increasing dentin thicknesses from different resin composites, with or without opacifiers, on a veneer dental preparation and resin disks. Material and methods: Artificial darkened lateral incisors with 1mm-thick veneers preparations were used to evaluate color mas...

The main goal of the modern dentist should be to address the urgent need to promote treatments focused on conservative dentistry, together with maintaining the health of the periodontium. Instead, iatrogenesis that results in the invasion of the biologic space is a significant and increasing problem in dentistry. The present case report illustrates...

Objectives: To evaluate the effects of the phosphoric acid (PA) etching, self-etching technique (SE) and blasting with Al2O3 particles (BL) on the bonding of a dental adhesive to intact (INT) or abraded (ABR) enamel. Methods: Enamel surfaces were treated as follows: 1- ABR-PA: INT was abraded with SiC paper and etched with PA (20 s) before Clearfil...

This study aimed to evaluate volumetric polymerization shrinkage, degree of conversion and Vickers hardness of four bulk-fill resin composites light-activated with their dedicated light curing units (LCUs). Four groups were evaluated, according to the type of composite and curing mode: Tetric EvoCeram Bulk-fill (TEBO) and Tetric EvoFlow Bulk-fill (...

Objective To describe a shift from injectable resin composite technique to composite resin computer‐aided design and computer‐aided manufacturing (CAD/CAM) veneers in addressing esthetic concerns associated with diastemas between anterior lower teeth in a clinical case. Clinical Considerations Among several techniques proposed for direct resin com...

This clinical case outlines a comprehensive digital workflow for a minimally invasive multidisciplinary treatment. The process utilizes one open-source software for digital wax-up and one low-cost software to address esthetic concerns related to teeth misalignment. The patient's function was stabilized with a digitally made occlusal splint. The app...

The natural outcome of dental composite restorations highly depends on the translucency of the enamel layer and fluorescence. This study aimed to evaluate the Translucency Parameter (TP) and Fluorescence Intensity (FI) of five different resin composite systems. Seven discs of each composite brand were prepared in a circular increasing thickness. Fo...

Objectives This article presents case reports highlighting over‐treatments with resin composites, often misconceived as minimally invasive procedures. Clinical Considerations Tooth‐colored restorative materials, such as ceramics and composites, have found widespread application to correct problems related to tooth color, shape, and alignment. When...

Purpose To evaluate the reliability and failure modes of ultrathin (0.5 mm) lithium disilicate, translucent and ultra‐translucent zirconia crowns for posterior teeth restorations. Materials and Methods Fifty‐four mandibular first molar crowns of three ceramic materials: (1) Lithium disilicate (e.max CAD, Ivoclar Vivadent), (2) 3Y‐TZP (Zirconn Tran...

Introduction: Currently, there is little clinical evidence to support the medium- and long-term survival and clinical performance of ultraconservative approaches using adhesive restorations in full-mouth restorations. The aim of this case series study was to evaluate the medium-term clinical performance of anterior and posterior adhesive restorati...

Objective: The objective of this study was to manufacture and to evaluate the physico-mechanical properties of the Lithium disilicate (Li2O5Si2) ceramic structures fabricated using additive manufacturing (3D printing). Methods: Li2O5Si2 samples were divided into (n = 30/group): SM (subtractively manufactured) and AR (additive/robocasting). For t...

Purpose To evaluate the effect of short curing time using a high-radiant emittance light on polymerization shrinkage vectors in different consistency bulk-fill composites (BFRCs) using micro-computed tomography. Methods and Materials Radiopaque zirconia fillers were homogeneously incorporated and functioned as radiopaque tracers into two regular-p...

Viemos (quando falo viemos, quero dizer eu vim, mas “nós” soa mais polido…) de uma cidade onde creio que um grande movimento se iniciou: Curitiba. Gostaria de ser mais preciso, e podem me corrigir, mas lá pelo fim da década de 80 e início da de 90, havia um grupo de Odontologia Estética com enfoque em resinas compostas, talvez o primeiro do Brasil,...

Objectives To evaluate the effect of argon plasma treatment (PLA) when combined with sandblasting (SAN), silanization (SIL), and hydrophobic bonding resin (HBR) on the shear bond strength (SBS) of a two-year water-aged resin composite bonded to a newly placed composite after 24 hours and one year of water-storage. Methods and Materials Thirty-six...

Objectives This study aims to evaluate the opalescence (OP) and color stability of composite resins over a period of 180 days and to compare composite resins’ OP with enamel’s OP.Materials and methodsTwenty human enamel specimens (5.0 × 0.3 mm) and 9 specimens (10.0 × 1.0 mm) of 10 colors of 4 different composite resins (3 M ESPE, FGM, Ivoclar-Viva...

Purpose This study evaluated the effect of different tightening protocols on the probability of survival of screw-retained implant-supported anterior crowns. Materials and methods Seventy-two implants with internal conical connections (4.0 × 10mm, Ti–6Al–4V, Colosso, Emfils) were divided into four groups (n = 18 each): 1) Manufacturer's recommenda...

Sempre me policio para não cair no mesmo erro das gerações que vieram antes da minha: o de achar que na época deles era tudo sempre melhor. Então, permito que você, leitor, me censure se eu cair nessa mesma armadilha. Sempre, novas ideias e tendências são vistas com desconfiança pelas gerações que já encontraram seu destaque profissional e seu “lug...

The increased emphasis on orofacial esthetics, experienced both by dental professionals and the lay public, results in an environment where overtreatment can easily occur. Patients on the one hand feel pressure from esthetic norms that are often unrealistic, while dental professionals are compelled to deliver immediate results many times without co...

Objectives: To compare the operative time and presence of air voids on Class II restorations fabricated by dental practitioners with 1 to 5 years of experience using incremental and bulk-filling techniques. Method and materials: Four techniques were evaluated: incremental, bulk-filling, bulk-filling with heated composite, and snowplow technique....

Introduction Universal adhesives were introduced to provide faster adhesive application and a less technique-sensitive procedure, however, there is a dearth of studies in the literature about the use of Universal adhesives in composite repair techniques. Objective To evaluate the effect of universal adhesives systems on the shear bond strength (SB...

Objective: To evaluate, in vivo, trueness and precision of two intraoral scanners, CEREC Omnicam (OMNI) and CEREC Primescan (PRIM), compared to a conventional impression serving as a master model. Method and materials: Impressions were performed for seven participants. For each participant, conventional polyvinylsiloxane impression and digital i...

“Ainda somos os mesmos e vivemos”, já dizia Belchior, na música “Como Nossos Pais”. Em pleno 2021, vivemos o novo, a revolução, o impacto da nova onda e das novas técnicas. E eu, como sou fascinado pelo novo, aceito e concordo.

Um ano após o início da pandemia, aqui estamos nós, ainda andando em círculos na resolução do problema. O que será após tudo isso saberemos somente “após tudo isso”. Quando dentro do furacão, somente pensamos em sair, e fica impossível fazer predições. Neste editorial, analisarei dois aspectos: a falta que todos sentem dos eventos presenciais e o c...

Objectives: To evaluate the effect of atmospheric pressure plasma (PLA), sandblasting (SAN), silanization (SIL) and hydrophobic bonding resin (HBR) on the micro-shear bond strength (MSBS) of fresh nanofilled (NF) or microhybrid (MH) composites to water-aged nanofilled composite. Materials and methods: NF plates were fabricated and stored in dist...

Statement of problem The light source stability of digital cameras and smartphones is important in shade matching in restorative and prosthetic dentistry to communicate objectively with the dental laboratory. Techniques that standardize the light source of such devices are lacking, and this limitation can lead to color mismatches, difficulties in c...

Objective To demonstrate a minimally invasive approach of a full‐mouth rehabilitation of a severe case of erosion treated with v‐shaped veneers, tabletops, overlays, veneerlays, laminate veneers, and a full contour veneer. Clinical considerations The present case report successfully rehabilitated a full‐mouth case of severely eroded teeth with min...

Objectives To perform a review on the influence of preheating and/or heating of resinous and ionomeric materials on their physical and mechanical properties and to discuss the benefits and methods of preheating/heating that have been used. Material and methods A search was performed in the Pubmed, Scopus, Scielo, and gray literature databases. In...

Tenho pensado muito na Odontologia atual: em que ponto perdemos o controle sobre os limites do marketing (travestido, sempre, de liberdade de mercado, influenciando não somente pacientes, mas também jovens odontólogos impressionáveis), e quando perdemos a noção do relacionamento profissional/paciente, no qual buscaríamos não o que ele quer, mas sim...

Objective: To evaluate color matching of universal composite restorations performed in anterior teeth using two evaluation methods. Materials and methods: Sixty class III preparations were made on denture central incisors with different shades (A1-A3) and restored with multishade (Tetric Evoceram, Filtek Universal, and TPH Spectra Universal) and...

Objective: To evaluate, through microcomputed tomography (μCT), the cement film thickness of veneers and crowns made with different provisional materials. Material and methods: A veneer and a crown preparation were performed on a central incisor and a second molar of a dental model, respectively, scanned with an intraoral scanner, and the .stl f...

Objective: To describe the use of the injectable resin composite restorative technique with a flowable resin material, in a clinical case with esthetic problems associated with irregular tooth anatomies, allied with a finishing, and polishing protocol due to staining after 1 year of use. Clinical considerations: The presented case report helped...

A Odontologia brasileira é a melhor do mundo! Esse slogan grandioso fala muito sobre nós mesmos e nossa identidade ufanista. A correlação que faço é: o futebol brasileiro é o melhor do mundo! Você concordaria ou discordaria? Temos, como país, uma certa baixo autoestima, clássica, de nos acharmos um pouco inferiores e um pouco isolados. Isso vem do...

Aim: Die silicone materials are used to build chairside composite restorations. The purpose of this study was to compare the flowability, dimension accuracy, and tear strength of four elastomeric die materials. Material and methods: Materials were divided into four groups: Mach-2 (M2), Scan Die (SD), GrandioSO Inlay System (GIS), and Impregum-F...

Background: Some composite resins contain luminophorous agents in order to reproduce tooth fluorescence. The objective of this study was to compare the fluorescence spectra emitted by composite resins with those of human enamel and dentin, and their emission behaviour after a 90-day natural aging period. Material and methods: Nine shades of the...

Objectives to evaluate the probability of survival and failure modes of lithium-disilicate, feldspathic-ceramic, and resin-nanoceramic anterior veneers cemented on dentin analog substrates after sliding-contact step-stress accelerated life testing (SSALT). Methods A virtual incisor tooth preparation was produced with a reduction of 1.5 mm at the i...

Purpose To evaluate gap formation of class II restorations, resin-filling techniques using microcomputed tomography (μCT) and scanning electronic microscopy (SEM) are discussed. Methods and Materials Class II cavities were prepared in 30 third molars and analyzed in distal and mesial views. Prime&Bond Universal adhesive was applied in all teeth an...

Purpose To evaluate volumetric polymerization shrinkage (VPS), shear bond strength (SBS) to dentin, and cohesive tensile strength (CTS) of bulk-fill resin composites (BFRCs) light activated by different modes. Methods and Materials Six groups were evaluated: Tetric EvoCeram bulk fill + high mode (10 seconds; TEC H10), Tetric EvoFlow bulk fill + hi...

Objective: To evaluate the influence of the degree of dentin moisture on interfacial ultramorphology and bond strength (μTBS) of universal adhesives. Materials and methods: Futurabond U (FBU), Scotchbond Universal (SBU), Adhese Universal (ADU), and Prime&Bond active (PBA) were used. After acid-etching, moist or over-dried dentin surfaces were te...

Objective: To quantify the volumetric polymerization shrinkage (VPS) of different conventional and bulk fill resin composites, through micro-computed tomography (μCT), and qualitative comparison of gap formation through optical coherence tomography (OCT). Methods: Box-shaped class I cavities were prepared in 30 third-molars and divided into 5 gr...

This technique article describes the duplication of a definitive implant-supported computer-aided design and computer-aided manufacture (CAD-CAM) crown with soft-tissue modification on a misplaced implant. Gingival contours were ideally shaped in the stone die, and a custom healing abutment was designed. After scanning the modified surface, images...

Proper gingival displacement is an important prerequisite to obtain good quality impressions. Retraction pastes could eliminate the need for retraction cords, as they have advantages such as comfort reported by patients, faster technique, ease of use, no need for anesthesia, and reduced tissue trauma. The objective of this paper was to present a cl...

Objectives: The present study evaluated the effect of a novel light-curing unit and experimental bulk fill composites on filler displacement compared to regular bulk fill materials, through polymerization shrinkage vectors, seen by micro-computed tomography scans. Methods: Spherical radiopaque zirconia fillers were homogeneously incorporated in th...

New resin-based restorative materials have been developed, such as computer-aided design/computer-aided manufacturing (CAD/CAM) and bulk-fill composites, as an alternative to traditional layering techniques. This study evaluated the biaxial flexural strength (BFS) before and after thermocycling of five different resin composites: one hybrid resin/c...

"Começo este editorial com uma história real e antiga, dessas que lembramos com carinho e ficam na memória emocional. Eu havia me formado e foi o primeiro ano em que, na Odontologia, um recém-formado poderia partir diretamente para a pós-graduação. Antes disso, os odontólogos eram obrigados a esperar dois anos para fazer qualquer especialização. Ei...

Objectives:: This study evaluated the effect of argon plasma treatment (PLA) and its combination with sandblasting (SAN), silanization (SIL), and hydrophobic bonding resin (HBR) application on the micro-shear bond strength of water-aged restorative resin composite to a newly placed composite, simulating restoration repair. Methods and materials::...

Aim: The present work aims to compare a digital dental histoanatomical analysis method with chemical enamel dissolution for the study of dental morphology. Material and methods: Extracted maxillary anterior teeth were scanned under microcomputed tomography (μCT) (μCT 40; Scanco Medical), segmented, and reconstructed three-dimensionally (Amira, v...

Cosmetic recontouring based on the enameloplas-ty of natural teeth is a treatment with esthetic benefits that can be considered both economical and safe. Not only does the clinician need to restore the harmony of the smile, but treatment planning must also take the functional aspects of the restoration into consideration. One way to recontour is th...

The stability and health of the periodontal tissues should be a common goal for all dental care providers with regard to natural or restored teeth as well as implant-supported restorations or any other type of prosthesis. The objective of this study was to address the key aspects to be respected when executing adhesive oral rehabilitations involvin...

Cosmetic recontouring based on the enameloplasty of natural teeth is a treatment with esthetic benefits that can be considered both economical and safe. Not only does the clinician need to restore the harmony of the smile, but treatment planning must also take the functional aspects of the restoration into consideration. One way to recontour is thr...

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Objective To describe a novel technique that helps the clinician on promoting a midline diastema closure with appropriate width proportions based on previous wax up, avoiding excesses of the resin material on the gingival area, which could lead to possible inflammation. Materials and Methods Two different silicone indexes were made over a wax up t...

Statement of problem: Color matching in restorative and prosthetic dentistry is important for the success of dental treatments, although communication with the dental laboratory remains subjective, and studies of the performance of objective communication methods are lacking. Purpose: The purpose of this study was to evaluate color differences (...

This study evaluated the color variability of hues B, C, and D between the VITA Classical shade guide (Vita Zahnfabrik) and four other VITA-coded ceramic shade guides using a digital camera (Canon EOS 60D) and computer software (Adobe Photoshop CC). A cross-polarizing filter was used to standardize external light sources influencing color match. A...

Objective To test the effects of different adhesive protocols and silane application on the adhesive durability to a Lithium Disilicate reinforced glass ceramic. Methods Forty disks of 13 mm diameter (E.max Press) were used. After etching with 9.5% HF for 20 seconds, disks were randomly assigned into 4 groups according to the adhesive/silane proto...

Objectives: The aim of this study was to quantify the internal void volume formation in commercially available, resin composites inserted using conventional or sonic insertion methods, and analyzed using three-dimensional (3D) micro-computed tomography (μCT). Methods and materials: Four resin composites were evaluated: one conventional (Herculit...

The understanding of cuspal deflection and volumetric shrinkage of resin composites is necessary to assess and improve the placement techniques of resin-based materials. The aim of this study was to investigate the cuspal deflection and its relationship with volumetric polymerization shrinkage of different bulk-fill resin composites. The investigat...

Purpose: To evaluate the probability of survival and failure modes of different external hexagon connection systems restored with anterior cement-retained single-unit crowns. The postulated null hypothesis was that there would be no differences under accelerated life testing. Materials and methods: Fifty-four external hexagon dental implants (∼4...

Articulation and occlusion test materials are tools used in daily prosthodontic and restorative procedures that aid the clinicians in the evaluation of adjacent and opposing natural and/or artificial tooth contacts. A precision micrometer (Series 293, Mitutoyo, Japan) with a resolution of 0.001 mm was used to measure the thickness of five articulat...

This study evaluated the influence of different light-curing modes on the volumetric polymerization shrinkage and degree of conversion of a composite resin at different locations using micro-computed tomography and Fourier transform infrared spectroscopy (FTIR). Specimens were divided into 4 groups based on the light-curing mode used (Bluephase 20i...

This study evaluated the effect of chlorhexidine dentin treatment on shear bond strength (SBS) of adhesive systems after different storages. The work included 144 third molars that had their dentin exposed and were divided in 6 groups: G1 (ASB+CHX: Adper Scotchbond 1XT + chlorhexidine 2 % prior Primer); G2(ASB); G3 (APP+CHX: Adper Prompt L-Pop + CH...

The aim of this study was to evaluate the effect of chlorhexidine (CHX) dentin treatment on microtensile bond strength (µTBS) of adhesive systems in different storage times. Occlusal enamel was removed from ninety third-molars and flat surfaces of middle dentin were exposed. Teeth were randomly divided in 6 groups according to adhesive system (etch...

Objective: The present work aims to evaluate the accuracy and validate a novel digital dental histo-anatomical analysis method for the study of dental morphology, when compared to chemical enamel dissolution. Methods: Extracted maxillary anterior teeth were scanned with micro-computed tomography (μCT 40; Scanco Medical AG), segmented and reconstru...

Objective: This work aims to present a pilot study of a non-destructive dental histo-anatomical analysis technique as well as to push the boundaries of the presently available restorative workflows for the fabrication of highly customized ceramic restorations. Materials and methods: An extracted human maxillary central incisor was subject to a m...

Objective: To evaluate the effect of light-curing wavelengths on composite filler particle displacement, and thus to visualize localized polymerization shrinkage in a resin-based composite (RBC) containing camphorquinone (CQ) and Lucirin TPO (TPO). Methods: Three light-curing units (LCUs) were used to light-cure a RBC containing CQ and TPO: a vi...

Statement of problem: Few studies have investigated the voids and gaps produced during the cementation of fiber posts using different techniques. Purpose: The purpose of this study was to evaluate and quantify void and gap area formations of different fiber post cementation techniques using microcomputed tomography (μCT). Material and methods:...

Abstract Objectives: The aim of this study was to determine the influence of heat treatment on the degree of conversion and chemical components of a regular and a bulk fill composite placed in a class-I cavity using Fourier transform infrared spectroscopy (FTIR) and Themogravimetric analysis (TGA). Materials and Methods: Materials were divided in 4...

Objectives: The present study sought to evaluate the reliability and failure modes of ultrathin (0.5 mm thickness) milled monolithic lithium disilicate full coverage molar restorations. Methods: Twenty one milled lithium disilicate full coverage restorations (IPS e.max CAD, Ivoclar Vivadent, Schaan, Liechtenstein) were resin-bonded onto composite r...

Objectives: To evaluate degree of conversion (DC), knop microhardness (KH) and polymerization shrinkage (PS) of a CQ/TPO composite after light-curing by different experimental light curing units (LCU): blue, violet and conventional. Methods: 3 groups were analyzed regarding different LCUs: G1 (violet), G2 (blue) and G3 (conventional: violet+blue)....

Quality assurance of indirect restorations should be performed by the dental laboratory before delivering the prosthetic parts to the clinician. Ultimately, it is the clinician’s responsibility to inspect and ensure, within the limits of clinically available technical and technological means, the quality of the prosthesis prior to insertion. Transi...

The ability to predict the final outcome prior to beginning treatment is highly desirable in all areas of Dentistry. This is especially true whenever the treatment produces an immediate alteration in esthetics and/or in function. Various technologies and techniques were developed and have evolved in an attempt to predict final outcomes and guide no...

Purpose: This study aimed to quantify polymerization shrinkage of one conventional and three bulk-fill composites, under bonded and unbonded conditions, in Class II preparations using 3D microcomputed tomography (μCT) and report its location. Materials and methods: Preparations (2.5 mm occlusal depth × 4 mm wide × 4 mm mesial box and 1 mm beyond...

Purpose: To show through computer-aided design and manufacturing technology combined with novel digital acquisition images and the right restorative material that the technology can provide an easier and predictable workflow for general practitioners. Basic procedure: This case report presents a fully digital treatment of a 59-year-old patient w...

Statement of problem: Few studies have investigated the volumetric polymerization shrinkage and film thickness of the different cementation techniques used to cement veneers. Purpose: The purpose of this in vitro study was to evaluate the volumetric polymerization shrinkage (VS) and film thickness (FT) of various cementation techniques through 3...

This article discusses the importance and advantages of incorporating noninvasive trial restorations into the esthetic treatment plan workflow. A new index fabrication technique using an overtray that ensures rigidity during mock-up fabrication or provisionalization is described. The overtray decreases distortion, improves cervical adaptation, and...

Purpose: To evaluate the presence and length of microcracks in resin-based materials finished with different techniques, using optical coherence tomography (OCT). Methods: Standardized Class V preparations (3×2×2mm) were made in the facial and lingual surfaces of 20 recently-extracted human third molars. 20 preparations were restored with a resin-b...

Purpose: To evaluate the presence and length of microcracks in resin-based materials finished with different techniques, using optical coherence tomography (OCT). Methods: Standardized Class V preparations (3x2x2mm) were made in the facial and lingual surfaces of 20 recently-extracted human third molars. 20 preparations were restored with a resi...

The present study aimed to characterize the pattern and volume of polymerization shrinkage of flowable resin composites, including one conventional, two bulk fill, and one self-adhesive. Standardized class I preparations (2.5 mm depth × 4 mm length × 4 mm wide) were performed in 24 caries-free human third molars that were randomly divided in four g...