Try a new search

Format these results:

Searched for:


Total Results:


Effect of argon plasma on repair bond strength using nanofilled and microhybrid composites

Negreiros, William Matthew; Ayres, Ana Paula Almeida; Willers, Amanda Endres; Hirata, Ronaldo; Giannini, Marcelo
OBJECTIVES/OBJECTIVE: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/METHODS:NF plates were fabricated and stored in distilled water for 4 months. The aged plates were assigned to the groups (n = 6): 1- untreated; 2- SAN + SIL + HBR; 3- HBR; 4- PLA + HBR; 5- SAN + HBR; 6- SAN + PLA + HBR; and 7- PLA. Two fresh composite cylinders were constructed on each plate with NF or MH composites and tested after 24 h or 1 year of water-storage, using the MSBS testing. Data were analyzed by three-way ANOVA and Tukey test (α = 0.05). RESULTS:NF yielded better outcomes than MH at 24 h, which was not observed at 1 year. HBR showed the highest MSBS results, while untreated and PLA groups yielded the lowest one. MSBS reduced for all groups after 1 year. CONCLUSIONS:Only HBR can obtain good MSBS results, while PLA alone was not beneficial. After 1 year, a reduction in repair MSBS was observed and the type of composite did not influence the results. CLINICAL RELEVANCE/CONCLUSIONS:The repair technique can be simplified with the use of only an adhesive and macromechanical retentions in the old composite, regardless the type of fresh composite.
PMID: 33881792
ISSN: 1708-8240
CID: 4847172

Full-mouth adhesive rehabilitation of a severe case of erosion treated with v-shaped veneers

Dallari, Giacomo; Scalzo, Ivan; Rosati, Riccardo Maria; Sampaio, Camila Sobral; Hirata, Ronaldo
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/UNASSIGNED:The present case report successfully rehabilitated a full-mouth case of severely eroded teeth with minimal healthy structure removal, maintaining viability of all teeth that were vital before the treatment started, and promoting long-lasting esthetic and functional results after 3 years of use. CONCLUSIONS:A deep knowledge of etiology, etiopathogenesis, and classifications of dental erosion will guide the clinician in the right direction for solving this issue correctly, according to modern prosthetic and conservative principles. CLINICAL SIGNIFICANCE/CONCLUSIONS:Dental erosion represents today a relatively widespread phenomenon among the global population and a significant challenge in each of its clinical stages for the clinicians who must treat it. In advanced stages, a careful evaluation phase of the case, a great patient motivation and a wise use of materials and clinical protocols are the success key of the case. Moreover, an advanced knowledge of adhesive dentistry is strictly required to successfully manage a severe erosion case with a modern and minimally invasive approach.
PMID: 33460516
ISSN: 1708-8240
CID: 4760252

The injectable resin composite restorative technique: A case report

Ypei Gia, Nathalia Ramos; Sampaio, Camila Sobral; Higashi, Cristian; Sakamoto, Antonio; Hirata, Ronaldo
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/UNASSIGNED:The presented case report helped to achieve an immediate highly esthetic restoration with appropriate width proportions based on a previous wax-up. After 1 year of use, restorations presented staining; therefore, finishing and polishing procedures were required to re-achieve acceptable esthetic results and thus increase restoration's survival. CONCLUSIONS:The use of the presented technique allowed to obtain a simple and predictable workflow; however, care must be taken on the follow up of the restorations due to intrinsic characteristics of the flowable resin material. CLINICAL SIGNIFICANCE/CONCLUSIONS:The use of the presented injectable technique helped on obtaining a precise anatomy replicating a diagnostic wax-up, thus improving marginal precision and achieving a highly esthetic and functional immediate outcome, with an easy workflow when appropriately planned and executed. However, it also presented low color stability after 1 year of use only, thus, requiring attention from clinicians in regard to its maintenance over time.
PMID: 32918395
ISSN: 1708-8240
CID: 4592262

Microcomputed tomography evaluation of cement film thickness of veneers and crowns made with conventional and 3D printed provisional materials

Sampaio, Camila S; Niemann, Katherin D; Schweitzer, Daniel D; Hirata, Ronaldo; Atria, Pablo J
OBJECTIVE:To evaluate, through microcomputed tomography (μCT), the cement film thickness of veneers and crowns made with different provisional materials. MATERIAL AND METHODS/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 files were exported to an LCD-based SLA three-dimensional (3D)-Printer. Twenty-four preparations were 3D-printed for each veneer and crown and divided into four groups (n = 6/group): (a) Acrylic resin (Acrílico Marche); (b) Bisacrylic resin (Protemp 4); (c) PMMA computer-aided design and computer-aided manufacturing (CAD-CAM) (Vipiblock); and (d) 3D-printed resin for provisional restorations (Raydent C&B for temporary crown and bridge). Veneers and crowns restorations were performed and cemented with a flowable composite. Each specimen was scanned with a μCT apparatus, files were imported for data analysis, and cement film thickness was quantitatively measured. Data were analyzed by 2-way ANOVA and Tukey post-hoc tests (α = .05). RESULTS:Crowns presented a thicker cementation film than veneers (P < .05).The bisacrylic resin showed the smallest veneer film thickness, similar to the acrylic resin (P = .151), which was not significantly different than the PMMA CAD/CAM material (P = .153). The 3D printed provisional material showed the thicker film, different than all other materials (P < .05). The bisacrylic resin showed a cement film thickness with a high number of voids in its surface. For crowns cementation, the 3D printed provisional material showed the thicker cementation film, different than all other materials (P < .05). CONCLUSIONS:Different provisional materials present different film thicknesses. The 3D printed provisional material showed the highest veneer and crown film thicknesses. Veneers film thicknesses were smaller than crowns for all provisional materials. CLINICAL SIGNIFICANCE/CONCLUSIONS:The 3D printed provisional material studied can be satisfactorily used, presenting appropriate adaptation with the tooth preparation, however, it shows the highest cement film thickness for both veneers and crowns cementations when compared with other provisional materials. A better internal fit, or smaller cement film thickness is obtained by CAD/CAM materials, acrylic and bisacrylic resins. Veneer cementation showed a smaller cement film thickness compared with crown cementation for all provisional materials.
PMID: 32937028
ISSN: 1708-8240
CID: 4593142

A comparison of ceramic crown color difference between different shade selection methods: Visual, digital camera, and smartphone

Jorquera, Gilbert J; Atria, Pablo J; Galán, Mariana; Feureisen, Josefina; Imbarak, Makarena; Kernitsky, Jeremy; Cacciuttolo, Franco; Hirata, Ronaldo; Sampaio, Camila S
STATEMENT OF PROBLEM/BACKGROUND: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 color communication, and treatment documentation. PURPOSE/OBJECTIVE:The purpose of this clinical study was to compare the magnitude of color difference (ΔE) among 3 shade selection methods during the fabrication of ceramic crowns: visual shade selection with a shade guide, digital shade selection with a digital camera and cross-polarizing filter, and digital shade selection with a smartphone and a light-correcting device. MATERIAL AND METHODS/METHODS:Forty-five patients in need of ceramic crowns were enrolled, and shade selection was evaluated according to different protocols: visual shade selection (A-D shade guide and IPS Natural Die Material Shade Guide, sent to the dental laboratory technician via a laboratory prescription); digital shade selection with a digital camera (D7000; Nikon Corp) with an 85-mm lens and wireless close-up flash, with and without a cross-polarizing filter (Polar eyes); and digital shade selection with a smartphone and a light-correcting device (iPhone XS attached to Smile Lite MDP, with and without its cross-polarizing filter accessory). Information from the smartphone was imported to an app (IPS e.max Shade Navigation App; Ivoclar Vivadent AG) that converted the reading to a shade and level of translucency for the ceramic restoration. For all photographs, a gray reference card with known color values was positioned by the mandibular teeth and was used for white balancing of the digital photographs with a software program. All photographs were edited and sent to the dental laboratory: white-balanced with the shade guide; white-balanced with the substrate shade guide; black and white; saturated; and cross-polarized. Ceramic crowns were made with the same lithium disilicate material (IPS e.max CAD; Ivoclar Vivadent AG) and cemented with the same resin cement (RelyX Ultimate Clicker, A3 shade; 3M). The ΔE values between the crown and the adjacent tooth were determined. The data were analyzed by using a 1-way analysis of variance (ANOVA) and Tukey posthoc tests (α=.05). RESULTS:The mean ΔE between a cemented ceramic crown and the adjacent tooth in the visual shade selection group was 5.32, significantly different than both digital camera (ΔE=2.75; P=.002) and smartphone (ΔE=2.34; P=.001), which were not different from each other (P=.857). CONCLUSIONS:The digital shade selection with photographs acquired with both a digital camera and a smartphone with a light-correcting device showed a threshold within the acceptable values (ΔE<3.7), whereas the visual shade selection showed an average ΔE above the threshold for acceptable values (ΔE>3.7). The use of a gray reference card helped standardize the white balance from the digital images.
PMID: 33741142
ISSN: 1097-6841
CID: 4821882

Analysis of the color matching of universal resin composites in anterior restorations

de Abreu, João Luiz Bittencourt; Sampaio, Camila Sobral; Benalcázar Jalkh, Ernesto Byron; Hirata, Ronaldo
OBJECTIVE:To evaluate color matching of universal composite restorations performed in anterior teeth using two evaluation methods. MATERIALS AND METHODS/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 single-shade (Omnichroma) universal composites (n = 5). For photographic analysis, a digital photograph of each specimen was taken under standardized set-up. Color measurements were taken in the center of the restoration, and in the tooth surface 1.0 mm adjacent from the tooth/restoration margin. CIELab coordinates were recorded and color difference analysis (ΔE) was made using the CIEDE-2000 formula. For visual analysis, calibrated observers performed visual scoring of color matching and differences were graded as 0:excellent match; 1:very good match; 2:not so good match; 3:obvious mismatch; 4:huge mismatch. All data were statistically analyzed using a linear mixed model analysis with a confidence interval of 95%. RESULTS:For photographic analysis, Omnichroma showed the highest ΔE compared to the other composites for all shades (P < .05), without difference among experimental groups regarding tooth shade. For visual analysis, Omnichroma showed the highest scores (P < .05) for all teeth shades, without differences between the other groups. Furthermore, there were no differences between visual scores for different shades of a same resin composite group. CONCLUSIONS:Multishade universal composites presented higher color matching than the single shade universal composite. There were no differences of color matching for different tooth shades for all composites. CLINICAL SIGNIFICANCE/CONCLUSIONS:Universal composites with increased color matching may be helpful to simplify anterior restorations, minimizing clinical errors.
PMID: 32989879
ISSN: 1708-8240
CID: 4616672

Opalescence and color stability of composite resins: an in vitro longitudinal study

Pepelascov, Daniele Esteves; de Castro-Hoshino, Lidiane Vizioli; da Silva, Leandro Herculano; Hirata, Ronaldo; Sato, Francielle; Baesso, Mauro Luciano; Centenaro, Alex Sandro; Novatski, Andressa; Neto, Antonio Medina; Terada, Raquel Sano Suga
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 methods: Twenty 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-Vivadent, Miscerium) and one brand of adhesive (3 M ESPE) were made. The results were obtained by measuring the reflectance and transmittance spectra in the visible region. After baseline measurement, composites and adhesive were analyzed after 2, 7, 30, 60, 120, and 180 days. The Lab color coordinates were used in the calculations of the OP parameter and color differences in the CIELab and CIEDE2000 methods. The data were analyzed statistically. Results: The materials tested showed variation and an increase in OP over time. The OP found for enamel was 18.06 ± 2.99, and some resins showed higher results. There was a strong correlation between the coordinate b*T and the OP over time. Enamel Plus was the only one material that presented no color changes during all periods in both color analyses. Filtek Z350 XT, AT, and BT did not show differences in any time when analyzed by CIELAB. Conclusions: The OP of most composite resins changed during the period of 180 days and was different from the OP of tooth enamel. In general, composites demonstrated small color changes over the period tested, being this characteristic material dependent. Clinical relevance: Natural teeth present different optical properties. Composite resins restorations should present properties similar to natural teeth and it is important that characteristics like color and opalescence remain stable over time.
ISSN: 1432-6981
CID: 5056972

Quo vadis, esthetic dentistry? Ceramic veneers and overtreatment"”A cautionary tale

Hirata, Ronaldo; Sampaio, Camila S.; de Andrade, Oswaldo Scopin; Kina, Sidney; Goldstein, Ronald E.; Ritter, Andre V.
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 considering what is best for the ill-informed patient. This article is an illustrated cautionary tale against overtreatment disguised as esthetic dentistry. Representative clinical examples illustrate how porcelain veneers are used without following sound operatory principles, as well as how these cases have been resolved.
ISSN: 1496-4155
CID: 5059912

Heating and preheating of dental restorative materials-a systematic review

Lopes, Larissa Coelho Pires; Terada, Raquel Sano Suga; Tsuzuki, Fernanada Midori; Giannini, Marcelo; Hirata, Ronaldo
OBJECTIVES/OBJECTIVE: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/METHODS:A search was performed in the Pubmed, Scopus, Scielo, and gray literature databases. In vitro studies published from 1980 until now were searched using the descriptors "composite resins OR glass ionomer cements OR resin cements OR adhesives AND heating OR preheating." Data extraction and quality of work evaluation were performed by two independent evaluators. RESULTS:At the end of reading the search titles and abstracts, 74 articles were selected. Preheating of composite resins reduces viscosity, facilitates adaptation to cavity preparation walls, increases the degree of conversion, and decreases the polymerization shrinkage. Preheating of resin cements improves strength, adhesion, and degree of conversion. Dental adhesives showed good results such as higher bond strength to dentin. However, unlike resinous materials, ionomeric materials have an increase in viscosity upon heating. CONCLUSIONS:Preheating improves the mechanical and physical properties. However, there is a lack of clinical studies to confirm the advantages of preheating technique. CLINICAL RELEVANCE/CONCLUSIONS:Preheating of dental restorative materials is a simple, safe, and successful technique. In order to achieve good results, agility and training are necessary so the material would not lose heat until the restorative procedure. Also, care is necessary to avoid bubbles and formation of gaps, which compromises the best restoration performance.
PMID: 33083851
ISSN: 1436-3771
CID: 4642822

Effect of Shortened Light-Curing Modes on Bulk-Fill Resin Composites

Sampaio, C S; Pizarro, P G; Atria, P J; Hirata, R; Giannini, M; Mahn, E
CLINICAL RELEVANCE/UNASSIGNED:Shortened light curing does not affect volumetric polymerization shrinkage or cohesive tensile strength but negatively affects the shear bond strength of some bulk-fill resin composites. When performing shortened light curing, clinicians should be aware of the light output of their light-curing units. SUMMARY/CONCLUSIONS: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 + high mode (TEF H10), experimental bulk fill + high mode (TEE H10), Tetric EvoCeram bulk fill + turbo mode (five seconds; TEC T5), Tetric EvoFlow bulk fill + turbo mode (TEF T5), and experimental bulk fill + turbo mode (TEE T5). Bluephase Style 20i and Adhese Universal Vivapen were used for all groups. All BFRC samples were built up on human molar bur-prepared occlusal cavities. VPS% and location were evaluated through micro-computed tomography. SBS and CTS tests were performed 24 hours after storage or after 5000 thermal cycles; fracture mode was analyzed for SBS.Results: Both TEC H10 and TEE H10 presented lower VPS% than TEF H10. However, no significant differences were observed with the turbo-curing mode. No differences were observed for the same BFRC within curing modes. Occlusal shrinkage was mostly observed. Regarding SBS, thermal cycling (TC) affected all groups. Without TC, all groups showed higher SBS values for high mode than turbo mode, while with TC, only TEC showed decreased SBS from high mode to turbo modes; modes of fracture were predominantly adhesive. For CTS, TC affected all groups except TEE H10. In general, no differences were observed between groups when comparing the curing modes.Conclusions: Increased light output with a shortened curing time did not jeopardize the VPS and SBS properties of the BFRCs, although a decreased SBS was observed in some groups. TEE generally showed similar or improved values for the tested properties in a shortened light-curing time. The VPS was mostly affected by the materials tested, whereas the SBS was affected by the materials, curing modes, and TC. The CTS was not affected by the curing modes.
PMID: 32101499
ISSN: 1559-2863
CID: 4735402