Niobium pentoxide addition to 3D printing resin-based composites Michaela dos Santos Kehl, Gabriela de Souza Balbinot, Vicente Castelo Branco Leitune, Alvaro Della Bona, Fabricio Mezzomo Collares Journal of the Mechanical Behavior of Biomedical Materials, 2026 To formulate a 3D Resin Based Composites (RBCs) with Nb 2 O 5 addition to induce mineral deposition, and evaluate its influence on mechanical, chemical, and biological properties. The experimental composite was formulated with UDMA (70 wt%), BisEMA (20 wt%), and TEGDMA (10 wt%). Barium glass (45 wt%) was used as an inorganic filler, and Nb 2 O 5 was incorporated into the composites at 2 wt% and 5 wt%. 3D RBCs without Nb 2 O 5 were used as a control. TPO (2 wt%) and diphenyl iodonium (1 wt%) were the photoinitiators. The degree of conversion, softening, and solvent, radiopacity, and cytotoxicity were evaluated. Flexural strength was tested following ISO 4049:2019. Mineral deposition was analyzed by Raman spectroscopy at the baseline and after 7, 14, and 28 days of artificial saliva immersion. All materials showed a degree of conversion above 90%. Softening in solvent was not affected by Nb 2 O 5 addition. Radiopacity results range from 0.9 mmAl to 1mmAl, with no influence of Nb 2 O 5. Cytotoxicity assays showed cell viability above 70% for all compositions. Flexural strength exceeded 100 MPa for all groups, reaching the ISO 449:2019 requirements. Mineral deposition analysis showed increased phosphate ion deposition in the 3D RBC with 2% and 5% Nb 2 O 5 , from early timepoints when compared to the control group. The addition of up to 5 wt% of Nb 2 O 5 on an experimental 3D RBC stimulated the mineral deposition of phosphate ions on the material surfaces without reducing the chemical, mechanical, and biological properties.
Effect of internal connection parameters on the fatigue limit of narrow-diameter implants – a finite element study Renan Brandenburg dos Santos, Ulysses Lenz, Jason Alan Griggs, Alvaro Della Bona Journal of Dentistry, 2026 OBJECTIVE: To evaluate the influence of internal connection parameters on the fatigue limit of narrow-diameter dental implants using finite element analysis (FEA). METHODS: A narrow-diameter dental implant (3.0 mm, Morse taper connection) and its corresponding abutment and screw were scanned using micro-computed tomography (micro-CT). High-resolution 3D models were reconstructed (Simpleware, Synopsis), and six geometric parameters defining the internal connection were extracted. A reference 3D assembly was built in SolidWorks, and systematic dimensional variations (±20%) of the six design parameters were introduced based on a Taguchi orthogonal array (DOE++, Reliasoft), resulting in 27 modified assemblies. Static FEA was performed in ABAQUS according to ISO 14,801:2016 geometry. Fatigue performance was estimated using Fe-safe software, and sensitivity analyses were conducted to identify the most influential parameters on the predicted fatigue limit. RESULTS: The reference model presented a fatigue limit of 193 N. Dimensional optimization based on FEA improved the fatigue limit up to 295 N, representing a 52.3% increase compared to the original design, with the cervical opening diameter (CID) showing a significant effect on fatigue performance. CONCLUSIONS: Systematic variation of internal connection geometry significantly affected the fatigue resistance of narrow-diameter implants. Identifying critical parameters enables the development of more durable and reliable implant-abutment assemblies, maximizing the treatment success in anatomically compromised sites. CLINICAL SIGNIFICANCE: Optimizing the internal geometry of narrow-diameter implants can improve load distribution, minimize mechanical complications, and increase the longevity of implant-supported rehabilitations in areas with reduced bone volume.
Simulated bone for dental implant in vitro testing: A systematic review Ulysses Lenz, Pedro Henrique Wenz Tretto, Jason Alan Griggs, Alvaro Della Bona Journal of Dentistry, 2026 OBJECTIVE: To evaluate methodological factors in the fabrication of simulated bone for dental implant testing and assess their relationship with reported clinical failure patterns. METHOD: A systematic search was conducted in MEDLINE/PubMed, Scopus, and Web of Science following PRISMA. In-vitro studies published from 2015 on mechanically testing single-unit implants with simulated bone materials were included. Two reviewers performed screening, data extraction, and RoBDEMAT appraisal. Disagreements were resolved by a third reviewer. A narrative synthesis categorized bone material characteristics, bone loss simulation, loading angulation, and implant connection type, analyzing their influence on reported outcomes. RESULTS: From 2,472 records, 91 studies met the inclusion criteria. Most studies used single-layer simulated bone (81/91), predominantly autopolymerizing resins, while 10 employed two-layer cortical-cancellous bone analogs. Bone loss was mostly simulated using 3 mm (n=41). Loading was commonly applied at 30° (n=61), followed by 0° (n=21). The most frequent outcomes were screw loosening (n=21), screw fracture (n=19), abutment fracture (n=19), crown/veneer fracture (n=19), and implant fracture (n=19). Off-axis loading (30-45°) combined with crestal bone loss (∼3mm) tended to shift failures from screw/abutment to implant fractures. CONCLUSIONS: Reported laboratory failures partly align with clinical observations. Simulated bone loss level, bone stiffness and loading angle can influence failure patterns in dental implant testing. ISO 14801 and related standard protocols require update to better reflect current clinical data. CLINICAL SIGNIFICANCE: Current laboratory tests do not fully reproduce contemporary peri-implant bone stability, limiting their clinical applicability. More realistic bone analogs may improve the clinical relevance of in-vitro studies.
Effect of CAD/CAM milling protocols on surface topography and mechanical behavior of polycrystalline zirconia Laura Carolina Kepler, Paula Benetti, Vitor Trancoso Britto, Alvaro Della Bona, Yu Zhang, Marcia Borba Dental Materials, 2026 Even though improvements in CAD/CAM technology have allowed the milling protocol to be modified according to specific treatment requirements, it remains unclear how different protocols affect the surface quality and mechanical properties of the final restoration. This study aims to evaluate the effect of the CAD/CAM milling protocol on the topography, flexural strength, and reliability of 3 mol% yttria partially stabilized zirconia (3Y-PSZ). Disc-shaped specimens (∅12 mm×1.2 mm) were fabricated using three different CAD/CAM dry-milling protocols (n = 20): slow (S), normal (N), and fast (F). Control polished specimens were fabricated by cutting pre-sintered CAD/CAM blocks using a cutting machine and polishing with silicon carbide papers, in wet (P wet ) and dry (P dry ) conditions (n = 20). Surface topography was evaluated using an optical profilometer (n = 3). Specimens were subjected to a piston-on-three-balls flexural strength test using a universal testing machine. Fractographic analysis was performed using optical and scanning electron microscopes. The characteristic flexural strength (σ 0 ), Weibull modulus ( m ), and the 90 % confidence intervals (90 % CI) were estimated. XRD was used to identify the tetragonal, cubic, and monoclinic phases. Distinct topographies were observed for polished and CAD/CAM-milled specimens. Surface roughness parameters (Sa and Sz) followed a decreasing order: F > N > S > P (P wet and P dry) There was no difference for σ 0 and m values among the three CAD/CAM milling protocols. P dry had similar σ 0 and m to CAD/CAM-milled groups, while P wet resulted in lower values. Distinct CAM-milling protocols produce apparent differences in the topography of 3Y-PSZ while preserving flexural strength and reliability. • Fast CAD/CAM milling produces rough and heterogeneous zirconia surfaces. • The CAD/CAM milling protocol has no effect on zirconia structural integrity. • Normal and slow protocols enhance surface finish while preserving zirconia’s properties. • Wet processing reduces the mechanical properties of polished zirconia.
Prevalence of Emotional Factors and Pain in Temporomandibular Disorder and Correlation With Different Diagnoses: A Cross-Sectional Study Gabriela Caovilla Felin, Cassiano Mateus Forcelini, Alvaro Della Bona Journal of Oral Rehabilitation, 2026 BackgroundTemporomandibular disorder (TMD) is a leading cause of orofacial pain, often associated with psychosocial factors that affect quality of life. Although these factors are well documented, the association with pain intensity and jaw function remains understudied.ObjectiveThis cross‐sectional observational study aimed to report the prevalence of emotional factors in patients with TMD and to correlate TMD with psychological factors, pain intensity and functional limitation of the jaw in a sample of the regional population.MethodsThis study used data from a TMD outpatient clinic in South America. Assessments included the DC‐TMD, chronic pain scale, GAD‐7 (anxiety), PHQ‐9 (depression), PHQ‐15 (somatic symptoms) and JFLS‐8 (jaw function) instruments. Sociodemographic data and the diagnosis of TMD were also reported. Data were statistically analysed using Kolmogorov–Smirnov, two‐tailed chi‐square, Fisher's exact, Mann–Whitney U, Kruskal–Wallis and Spearman's correlation coefficient tests (α = 0.05).ResultsFrom 190 patients (mean age 43.5), 78.4% were women, 31.5% had low education and 44.7% had a household income lower than US$ 500. The majority had TMD with pain and joint disorder. The overall chronic pain score was 63, indicating high pain intensity. Psychosocial scores and jaw limitations were mild. Women showed higher pain levels, more functional limitations, and elevated psychosocial scores.ConclusionPsychological factors did not differ significantly across TMD subtypes but were highly prevalent, especially in women.
Influence of silica nanoparticle concentration on 3-dimensional–printed resin-based composite Francisco Amaro Morganti, Ana Cristina Andriolli Zattera, Gabriela de Souza Balbinot, Alvaro Della Bona, Fabricio Mezzomo Collares Jada Foundational Science, 2026 <h2>Abstract</h2><h3>Background</h3> Nanoparticle load may interfere with the viscosity of the composites, challenging the printability in vat-polymerization techniques. This study aimed to evaluate the influence of silica nanoparticle addition on the physicochemical properties of a 3-dimensional (3D)-printed resin-based composite (RBC). <h3>Methods</h3> The resinous matrix of the experimental 3D RBC was kept fixed with the addition of silica nanoparticles (Aerosil OX50; Evonik), which were surface-treated with 3-(trimethoxysilyl) propyl methacrylate and used as fillers at 5 wt% (silicon dioxide [SiO<sub>2</sub>] 5%), 10 wt% (SiO<sub>2</sub>10%), and 20 wt% (SiO<sub>2</sub>20%). The composite's viscosity was evaluated before printing. Specimens were 3D printed (Anycubic Photon Mono 4K 3D Printer; Anycubic Inc), cleaned with 96% ethanol, and postcured (Form Cure; Formlabs) at 60 °C. Specimens were evaluated for their radiopacity, polymerization kinetics, and degree of conversion. The flexural strength was assessed after 24 hours and 14 days of water storage. <h3>Results</h3> Silica nanoparticles were a median size of 65 nm (d<sub>10</sub>: 35 nm; d<sub>90</sub>: 129 nm). The addition of silica nanoparticles resulted in a 2-fold increase in the resin viscosity, without modifying the specimens' radiopacity. All groups presented more than 80% degree of conversion, but a faster polymerization with higher polymerization rates was observed for the SiO<sub>2</sub>5%. Despite the increased immediate flexural strength (mean [SD], 81.78 [3.14] MPa) shown by SiO<sub>2</sub>20%, the strength was reduced for all experimental groups after 14 days in water. <h3>Conclusions</h3> Increasing concentrations of silica nanoparticles increased 3D RBC properties. However, after 14 days of water storage, decreased flexural strength was observed.
Adaptation, Marginal, and Occlusal Quality of Monolithic Zirconia Crowns: Effect of the CAD/CAM Milling Protocol Indiarai Lavandoski Bringhenti, Andressa Restani Oliveira, Natalia Ulmi Ziglioli, Vitor de Trancoso de Britto, Alvaro Della Bona, Marcia Borba Journal of Esthetic and Restorative Dentistry, 2026 Objectives Variables related to CAD/CAM processing can affect the final quality of all‐ceramic crowns. This study aims to evaluate the effect of the milling protocol on the adaptation, marginal and occlusal quality of monolithic zirconia crowns. Materials and Methods Thirty‐nine monolithic zirconia crowns were produced using three CAD/CAM milling protocols ( n = 13): slow (S), normal (N), and fast (F). Adaptation (gap thickness) was evaluated using the replica technique, while marginal quality was assessed according to a severity scale. Occlusal quality was investigated qualitatively, using a stereomicroscope, and quantitatively, through an occlusal dimensional discrepancy analysis. Gap thickness and occlusal discrepancy data were analyzed with ANOVA and Tukey's test, and marginal quality with Kruskal–Wallis and Student–Newman–Keuls ( α = 0.05). Results Gap thickness in the marginal, gingival‐axial angle and axial regions was similar among groups. In the axio‐occlusal angle and occlusal region, group N presented the smallest gap. For marginal quality, group F had higher scores in the severity scale than groups N and S for the mesial and buccal regions. Group F crowns showed less refined occlusal anatomy. Yet, when crowns produced with S and F protocols were compared with N, the total mean discrepancy was similar. Conclusion The CAD/CAM milling protocol affected the adaptation, marginal, and occlusal quality of monolithic zirconia crowns.
Fatigue Resistance of Customized Implant-Supported Restorations Ulysses Lenz, Renan Brandenburg dos Santos, Megha Satpathy, Jason A. Griggs, Alvaro Della Bona Materials, 2025 The design of custom abutments (CA) can affect the mechanical reliability of implant-supported restorations. The purpose of the study was to evaluate the influence of design parameters on the fatigue limit of CA and to compare optimized custom designs with the reference abutment (RA). A morse-tapered dental implant, an anatomical abutment, and a connector screw were digitalized using microcomputed tomography. A cone beam computed tomography scan was obtained from one of the authors to virtually place the implant-abutment assembly in the upper central incisor. Ten design parameters were selected according to the structural geometry of the RA and the implant planning. A reverse-engineered RA model was created in SOLIDWORKS and was modified considering a Taguchi orthogonal array to generate 36 CAs with ±20% dimensional variations. Finite element analysis was conducted in ABAQUS, and fatigue limits were estimated using Fe-safe. ANOVA (α = 0.1) identified the most influential parameters. Von Mises stress values ranged from 229 MPa to 302 MPa, and 94.4% of the CAs had a higher fatigue limit than the RA. Three parameters significantly affected the fatigue performance of the implant system. The design process of custom abutments includes critical design parameters that can be optimized for longer lifetimes of implant-abutment restorations.
RoBDEMAT: A risk of bias tool and guideline to support reporting of pre-clinical dental materials research and assessment of systematic reviews António HS Delgado, Salvatore Sauro, Adriano F. Lima, Alessandro D. Loguercio, Alvaro Della Bona, Annalisa Mazzoni, Fabricio Mezzomo Collares, Frode Staxrud, Jack Ferracane, James Tsoi, Julia Amato, Klaus W. Neuhaus, Laura Ceballos, Lorenzo Breschi, Matthias Hannig, Mary Anne Melo, Mutlu Özcan, Nicola Scotti, Niek Opdam, Satoshi Yamaguchi, Sebastian Paris, Lezize Sebnem Turkun, Sophie Doméjean, Vinicius Rosa, William Palin, Falk Schwendicke Journal of Dentistry, 2022
Mechanical behavior and adhesive potential of glass fiber-reinforced resin-based composites for use as dentin analogues American Journal of Dentistry, 2020
Instrumental shade matching Razvan Ionut Ghinea, María del Mar Pérez Gómez, Luis Javier Herrera Maldonado, Oscar Emilio Pecho Yataco, Alvaro Della Bona Color and Appearance in Dentistry, 2020
Color science and its application in dentistry María del Mar Pérez Gómez, Razvan Ionut Ghinea, Ana María Andreea Ionescu, Oscar Emilio Pecho Yataco, Alvaro Della Bona Color and Appearance in Dentistry, 2020
Visual shade matching María del Mar Pérez Gómez, Juan de la Cruz Cardona Pérez, Razvan Ionut Ghinea, Oscar Emilio Pecho Yataco, Alvaro Della Bona Color and Appearance in Dentistry, 2020
Whiteness difference thresholds in dentistry María M. Pérez, Luis Javier Herrera, Francisco Carrillo, Oscar E. Pecho, Diana Dudea, Cristina Gasparik, Razvan Ghinea, Alvaro Della Bona Dental Materials, 2019
Effect of temperature and storage time on dental bleaching effectiveness Luiz Alexandre Chisini, Marcus Cristian Muniz Conde, Sônia Saeger Meireles, Raquel Venâncio Fernandes Dantas, Hugo Ramalho Sarmento, Álvaro Della Bona, Marcos Britto Corrêa, Flávio Fernando Demarco Journal of Esthetic and Restorative Dentistry, 2019
A Novel Silica-Nylon Mesh Reinforcement for Dental Prostheses Tarcisio José de Arruda Paes-Junior, Humberto Lago de Castro, Alexandre Luiz Souto Borges, Alvaro Della Bona, Fernanda de Cássia Papaiz Gonçalves Advances in Materials Science and Engineering, 2017
Microcosm biofilm formation on titanium surfaces Claudio Zeferino Dal’Agnol, Letícia Stefenon, Françoise Hélène van De Sande, Álvaro Della Bona, Maximiliano Sérgio Cenci, Bruna Webber, Laura Beatriz Rodrigues, Luciana Ruschel dos Santos Materials Research, 2015
Influence of CAD-CAM diamond bur deterioration on surface roughness and maximum failure load of Y-TZP-based restorations American Journal of Dentistry, 2015
Color difference thresholds in dentistry Rade D. Paravina, Razvan Ghinea, Luis J. Herrera, Alvaro D. Bona, Christopher Igiel, Mercedes Linninger, Maiko Sakai, Hidekazu Takahashi, Esam Tashkandi, Maria del Mar Perez Journal of Esthetic and Restorative Dentistry, 2015
Adhesion to Dental Ceramics Alvaro Della Bona, Márcia Borba, Paula Benetti, Oscar E. Pecho, Rodrigo Alessandretti, João Cezar Mosele, Rafael Tagliari Mores Current Oral Health Reports, 2014
Effect of endodontic sealers on tooth color Débora Könzgen Meincke, Maíra Prado, Brenda Paula Figueiredo Gomes, Alvaro Della Bona, Ezilmara Leonor Rolim Sousa Journal of Dentistry, 2013
Bond strength of a resin cement to high-alumina and zirconia-reinforced ceramics: The effect of surface conditioning Journal of Adhesive Dentistry, 2006
