Guilherme Carpena Lopes

Prof. Guilherme Carpena Lopes

orcid

Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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30 January 2023 in European Journal of Dentistry
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Journal Article
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FFFranciele Floriani
Franciele Floriani
GLGuilherme Carpena Lopes
Guilherme Carpena Lopes
ACAlexandre Cabrera
Alexandre Cabrera
WDWagner Duarte
Wagner Duarte
PZPanagiotis Zoidis
Panagiotis Zoidis
MRMateus Garcia Rocha
Mateus Garcia Rocha
This article compares the accuracy of intraoral scanners (IOSs) used in the digital impression of full arches to fabricate implant-supported complete prostheses. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and was registered in the Open Science Framework (DOI 10.17605/OSF.IO/CPM9K). Six electronic databases, gray literature databases, and a manual search were performed in April 2022. Studies that evaluated the accuracy of intraoral scan impressions compared with conventional impressions in full-arch impressions were included for complete implant-supported prostheses. In addition, an adapted checklist for reporting in vitro studies was used to assess the risk of bias. Meta-analysis was conducted using a random-effects Hunter– Schmidt model. Nine studies were included in the analysis. IOS impressions present higher accuracy (137.86 μm) than conventional impressions (182.51 μm) (p<0.001). The heterogeneity of the study's methodology was I2¼18.34. However, impression accuracy varies significantly with scan body type, IOS type, scanning strategy, and modification technique. For most IOS systems, the acceptable clinical threshold of linear accuracy of 200 μm can be achieved, except for the True Definition Scanner in one of the studies. Based on the results of the included studies, digital impressions using IOS present similar or better linear accuracy than conventional impression techniques.

4 March 2024 in Dentistry Journal
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Journal Article
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FFFranciele Floriani
Franciele Floriani
Carlos Alberto JuradoCarlos Alberto Jurado
Carlos Alberto Jurado
SASalahaldeen Abuhammoud
Salahaldeen Abuhammoud
MVMarcos Vargas
Marcos Vargas
Nicholas G FischerNicholas G Fischer
Nicholas G Fischer
GLGuilherme Carpena Lopes
Guilherme Carpena Lopes
Background: We compared the repeatability of the shade determination of resin composite restorations and acrylic teeth in light and darker shades at baseline and after an aging process through two digital tooth color-matching methods: using a Trios 3Shape intraoral scanner and using a Vita Easyshade Compact spectrophotometer. Material and Methods: Forty upper central incisor acrylic teeth in the shade A1 (n = 10) and A3 (n = 10) were randomly assigned to be restored with Filtek Bulk Fill in the shade A1 (n = 10) or A3 (n = 10). Subsequently, 20 Class V cavities were prepared in a standardized manner (mesio-distal = 3.0 mm, cervical–occlusal = 2.0 mm, depth = 1.5 mm). Cavities were restored using an universal adhesive system and resin composite in two increments and were light-cured. The shade difference between the resin composite Class V restorations in acrylic teeth of the A1 and A3 shades was evaluated at baseline and after aging. Aging was simulated using ultraviolet light for 120 h. An Easyshade device and an intraoral scanner were used under D65 illumination. Measurements were taken five times, on top of the restoration and on the acrylic teeth, in a randomized manner. Results: Data analysis was on the calculation of the arithmetic mean for the percentage of repeatability conducted by the Trios scanner and the Easyshade device. There was no statistically significant comparison between the shade measurement devices (p > 0.05). At baseline, the repeatability for both the Trios intraoral scanner and the Vita Easyshade Compact device for artificial teeth in the shades A1 and A3 was 100%. After aging, the trueness recorded by the intraoral scanner and the Easyshade device for artificial teeth in the shade A1 was 80%. For Class V restoration with shade A1, the intraoral scanner recorded 80% trueness and the Easyshade device recorded 60% trueness at baseline. For shade A3, the intraoral scanner recorded 60% trueness and the Easyshade device recorded 60% trueness. Conclusions: The intraoral scanner and Easyshade device are reliable for baseline shade selection, but their accuracy decreases after aging, particularly for darker shades.

1 January 2019 in Brazilian Oral Research
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Journal Article
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TPTamara Paludo
Tamara Paludo
MMMaurem Leitão Marcondes
Maurem Leitão Marcondes
ASAndré Arigony Souto
André Arigony Souto
GLGuilherme Carpena Lopes
Guilherme Carpena Lopes
ALAlessandro D Loguercio
Alessandro D Loguercio
ASAna Maria Spohr
Ana Maria Spohr
The aim was to evaluate the effect of 2% grape seed extract (GSE) containing phosphoric acid (PhA) on the bond strength to enamel and dentin. The control group was 37% PhA. The following three PhA formulations with 2% GSE and 20% ethanol were obtained: GSE5 = 5% PhA; GSE10 = 10% PhA; and GSE20 = 20% PhA. The enamel and dentin surfaces of molars were etched with the acid solutions, followed by Scotchbond Multi-Purpose adhesive and composite resin application. The tensile bond strength (TBS) test evaluated the bond to enamel after 24 h, and the microtensile bond strength (μTBS) test evaluated the bond to dentin after 24 h and 12-month water storage. Etched enamel and dentin were observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. The TBS data were submitted to one-way ANOVA, while µTBS data were submitted to two-way ANOVA and Tukey’s test (α = 0.05). The TBS (MPa) to enamel did not significantly differ among the control (48.1 ± 15.7), GSE5 (46.1 ± 9.6), GSE10 (49.8 ± 13.6) and GSE20 (44.1 ± 11.9) groups (p = 0.537). The µTBS (MPa) to dentin of the control (28.4 ± 14.4) and GSE20 (24.1 ± 8.1) groups were significantly higher than those of the GSE5 (16.8 ± 7.4) and GSE10 (17.5 ± 6.6) groups at 24 h (p < 0.006). After 12-month storage, only GSE5 (21.0 ± 7.8) and GSE10 (17.6 ± 8.0) did not show significantly decreased μTBS (p > 0.145). SEM micrographs showed a shallower enamel etching pattern for GSE5. AFM images showed the formation of collagenous globular structures for GSE5 and GSE10. The different acid solutions did not influence the TBS to enamel, and the µTBS to dentin was stable over time when dentin was etched with GSE5 and GSE10.

27 July 2025 in Journal of Esthetic and Restorative Dentistry
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Journal Article
Open access
JPJorge Perdigao
Jorge Perdigao
FZFernanda P. Zatt
Fernanda P. Zatt
GLGuilherme Carpena Lopes
Guilherme Carpena Lopes
NCNatália B. Caon
Natália B. Caon
RCRuoqiong Chen
Ruoqiong Chen
Objective: Characterize the morphology and distribution of filler particles of universal composite resins using Scanning Electron Microscopy, and calculate the residual filler mass fraction (filler wt%) of each composite resin with Thermogravimetric Analysis to compare the data with the respective filler wt% reported in the literature. Methods: Seven universal composite resins (CRs) were analyzed in this study: Essentia Universal (EU), Filtek Easy Match (EM), Filtek Universal (FU), Omnichroma (OM), Simplishade (SS), TPH Spectra ST HV (ST), and Venus Diamond One (VO). Two classic multi‐shade CRs, Charisma Opal (CO) and Estelite Omega (EO) were used as controls. Two grams of each CR were dissolved in acetone, and the respective filler residue was dried and mounted on aluminum stubs. The specimens were sputter‐coated with Pt and observed under a Field‐Emission Scanning Electron Microscope to analyze the particle size and distribution at magnifications from ×5000 to ×80,000. For the Thermogravimetric Analysis, CR specimens were continuously weighed while heating up to 1000 o C to burn the organic contents and calculate the residual mass fraction of each material. Results: Electron microscopy—OM showed a monomodal particle distribution of individual microparticles that contained nanoparticles. Sporadic agglomerations of microparticles were also observed for OM. EO, EU, FU, ST, VO, and EM displayed a bimodal filler distribution. The particles of CO and SS were organized under a trimodal distribution. There were similarities in particle shape and distribution for EM and FU, as well as for EO and OM. Classic particles of irregular shape larger than 2 μm were observed for CO, EU, ST, and VO. Clusters of nanoparticles up to 7.5 μm wide were observed for EM, FU, and SS. Thermogravimetric Analysis—The measured filler wt% was material specific. It ranged from 66.27% for EU to 78.28% for VO. The relative difference between the filler wt% measured for VO compared to the filler wt% reported in the literature was the smallest (−3.4%). EU resulted in the widest discrepancy (−18.2%). Conclusion: The particle size and distribution varied for each composite resin, except for the pairs of materials EO/OM and EM/FU made by the same manufacturer. The filler wt% measured in this study was not in agreement with the description provided in the current literature for any of the CRs tested.

1 January 2024 in Case Reports in Dentistry
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Journal Article
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FFFranciele Floriani
Franciele Floriani
NCNatália Fiuza Coelho
Natália Fiuza Coelho
LLLudimila de Azevedo Linhares
Ludimila de Azevedo Linhares
SSSheila Cristina Stolf
Sheila Cristina Stolf
GLGuilherme Carpena Lopes
Guilherme Carpena Lopes
This case report details the esthetic rehabilitation of a 32‐year‐old male patient suffering from sleep bruxism, primarily manifesting as a fracture and significant loss of tooth structure in the anterior maxillary central incisors. To address these concerns, the patient underwent a restorative treatment involving the application of semidirect resin composite veneers on the maxillary incisors and direct resin composite restoration on the incisal regions of the maxillary canines. This approach not only restored the functional integrity of the teeth but also significantly enhanced the patient’s esthetic appearance.

31 October 2024 in Dentistry Journal
Verified
Journal Article
Open access
PDF file
FFFranciele Floriani
Franciele Floriani
Carlos Alberto JuradoCarlos Alberto Jurado
Carlos Alberto Jurado
NMNikkita Madhu
Nikkita Madhu
MLMark A. Lackey
Mark A. Lackey
FAFrancisco X. Azpiazu-Flores
Francisco X. Azpiazu-Flores
GLGuilherme Carpena Lopes
Guilherme Carpena Lopes
Background: This study aimed to evaluate the color stability of bulk-fill flowable resin composites with 2 difference shades at baseline and after artificial aging. Methods: Disk-shaped specimens (Ø10 × 4 mm) were fabricated from three bulk-fill flowable resin resin composites (Filtek Bulk-Fill Flow, Venus Bulk-Fill Flow, and Estelite Bulk-Fill Flow). The specimens in each bulk-fill resin composite group were divided into two subgroups (n = 10 per subgroup) with two different shades, A1 (N = 30) and A3 (N = 30), and were polymerized with light curing (800 mW/cm2/Valo LED Unit, Ultradent) and polished. The color difference between bulk-fill resin composites was evaluated at baseline and after artificial aging using a spectrophotometer (CM-700d, Konica Minolta, Tokyo, Japan) under D65 illumination. Color coordinates were measured with CIEDE2000, and color differences (∆E00) and relative translucency parameter (RTP) values were calculated. Subsequently, the comparison of color changes (∆E00) before and after thermocycling was performed using the t-test for paired samples. Results: The bulk-fill flow resin composites evaluated in the present study were capable of mimicking important optical properties such as light transmission. All the resin composites provided acceptable color stability at baseline and after thermocycling when the color A1 was used. On the other hand, whenever the shade A3 was used, the Venus Bulk-Fill Flow demonstrated the best optical properties. There was no statistically significant difference when comparing baseline and after thermocycling in bulk-fill flowable resin composites (p > 0.05). After thermocycling, A1 bulk-fill flowable resin composites provided acceptable color stability, and all A3 bulk-fill flowable resin composites provided visible color change, except for the Venus Bulk-Fill Flow (∆E00 = 2.35). Conclusions: Estelite Bulk-Fill Flow displayed the best color stability (∆E00 = 2.22) between all the combinations evaluated.