Darcio Fonseca

Dr. Darcio Fonseca


Research Focus & Metrics

Academic Career Length

3Years (2024-Present)

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

Representative Publications

View All Publications
15 June 2024 in Materials
Verified
Journal Article
Open access
DFDarcio Fonseca
Darcio Fonseca
BTBeatriz de Tapia
Beatriz de Tapia
RPRamon Pons
Ramon Pons
Conrado AparicioConrado Aparicio
Conrado Aparicio
FGFernando Guerra
Fernando Guerra
Javier GilJavier Gil
Javier Gil
Implantoplasty is a technique increasingly used to remove the biofilm that causes peri-implantitis on dental implants. This technique of mechanization of the titanium surface makes it possible to eliminate bacterial colonies, but it can generate variations in the properties of the implant. These variations, especially those in fatigue resistance and electrochemical corrosion behavior, have not been studied much. In this work, fatigue tests were performed on 60 dental implants without implantoplasty, namely 30 in air and 30 in Hank’s solution at 37 °C, and 60 with implatoplasty, namely 30 in air and 30 in Hank’s solution at 37 °C, using triaxial tension–compression and torsion stresses simulating human chewing. Mechanical tests were performed with a Bionix servo-hydraulic testing machine and fracture surfaces were studied by scanning electron microcopyElectrochemical corrosion tests were performed on 20 dental implants to determine the corrosion potentials and corrosion intensity for control implants and implantoplasty implants. Studies of titanium ion release to the physiological medium were carried out for each type of dental implants by Inductively Coupled-Plasma Mass Spectrometry at different immersion times at 37 °C. The results show a loss of fatigue caused by the implantoplasty of 30%, observing that the nucleation points of the cracks are in the areas of high deformation in the areas of the implant neck where the mechanization produced in the treatment of the implantoplasty causes an exaltation of fatigue cracks. It has been observed that tests performed in Hank’s solution reduce the fatigue life due to the incorporation of hydrogen in the titanium causing the formation of hydrides that embrittle the dental implant. Likewise, the implantoplasty causes a reduction of the corrosion resistance with some pitting on the machined surface. Ion release analyses are slightly higher in the implantoplasted samples but do not show statistically significant differences. It has been observed that the physiological environment reduces the fatigue life of the implants due to the penetration of hydrogen into the titanium forming titanium hydrides which embrittle the implant. These results should be taken into account by clinicians to determine the convenience of performing a treatment such as implantoplasty that reduces the mechanical behavior and increases the chemical degradation of the titanium dental implant.

1 June 2026 in Dentistry Journal
Verified
Journal Article
Open access
PDF file
EPEsteban Padullés-Roig
Esteban Padullés-Roig
DFDarcio Fonseca
Darcio Fonseca
JCJuan Antonio Callejas-Cano
Juan Antonio Callejas-Cano
LDLuis M. Delgado
Luis M. Delgado
EOEster Lopez Oliva
Ester Lopez Oliva
Javier GilJavier Gil
Javier Gil
Background/Objectives: Peri-implantitis is a common complication affecting approximately 24% of dental implants and is characterized by progressive bone loss and reduced implant stability. Implantoplasty, an intraoral procedure used to remove biofilm by machining the titanium implant surface, has become increasingly common in clinical practice. However, this procedure may compromise the mechanical integrity of implants, especially when combined with peri-implant bone loss, potentially leading to premature fatigue failure. This study evaluated the effect of different marginal bone resection depths, with and without implantoplasty, on the cyclic mechanical behavior of dental implants. Methods: A total of 200 commercially pure grade 4 titanium implants were embedded in resin simulating human bone at depths of 3, 4, and 5 mm. A subset of implants underwent implantoplasty with a 0.4 mm surface reduction corresponding to the thread width. Finite element analysis was performed to evaluate von Mises stress distribution and predict fatigue behavior. Numerical results were experimentally validated using a servo-hydraulic MTS Bionix system under ISO 14801:2016 conditions. Fatigue limits were determined from the asymptotic region of the load–cycles-to-failure (S–N) curves, and fracture surfaces were examined by scanning electron microscopy. Results: Maximum von Mises stresses were concentrated at the thread–body transition and increased with greater marginal resection depth, with additional stress amplification observed after implantoplasty. Fatigue limits for untreated implants were approximately 351 N, 285 N, and 210 N for 3-, 4-, and 5 mm resections, respectively. Implants subjected to 0.4 mm implantoplasty showed fatigue limits of 311 N, 270 N, and 90 N, respectively. Failure patterns were load-dependent: higher loads produced coronal fractures, whereas lower loads resulted in failure at the implant–abutment connection. Finite element predictions showed strong agreement with the experimental results. Conclusions: Excessive marginal resection significantly decreases the fatigue resistance and long-term mechanical reliability of dental implants, particularly when combined with implantoplasty. The main limitations of this study include is in vitro design, the assumptions inherent to the numerical models, and the variability associated with implantoplasty procedures.

6 March 2026 in Preprints.org
Verified
Preprint
Open access
PDF file
ERESTEBAN PADULLÉS - ROIG
ESTEBAN PADULLÉS - ROIG
PSPablo Sevilla
Pablo Sevilla
Eugenio Velasco-OrtegaEugenio Velasco-Ortega
Eugenio Velasco-Ortega
MCMiguel Cerrolaza
Miguel Cerrolaza
DFDarcio Fonseca
Darcio Fonseca
Javier GilJavier Gil
Javier Gil
The increasing prevalence of peri-implantitis has led to a growing clinical use of implantoplasty, a procedure involving intraoral machining of the dental implant sur-face to remove biofilm. The absence of standardized clinical protocols may contribute to premature fatigue failure of dental implants. The present study aimed to determine the influence of machining depth on the cyclic mechanical behavior of dental im-plants. A total of 250 commercially pure Grade 3 titanium dental implants were dis-tributed into four groups according to machining depth: untreated (original), 0.2 mm, 0.4 mm, and 0.6 mm wall reduction. The implant system featured an internal connec-tion with a thread height of 0.4 mm. Finite element analysis was performed for each machining depth to evaluate Von Mises stress distribution and to simulate fatigue be-havior. The numerical models were validated through experimental fatigue testing using a servohydraulic MTS Bionix testing machine under ISO 14801:2016 standard conditions. Fractographic analysis was conducted by scanning electron microscopy. The results revealed that maximum Von Mises stresses were concentrated at the junc-tion between the implant thread and the implant body. The fatigue limit of the un-treated implants was approximately 400 N. Implants subjected to 0.4 mm machining exhibited a fatigue limit of 350 N, whereas lower fatigue limits were observed for 0.2 mm (290 N) and 0.6 mm (180 N) reductions. These findings demonstrate the signifi-cant mechanical effect of thread removal. At higher applied loads, fracture occurred in the coronal region of the implant, whereas at lower loads failure shifted to the im-plant–abutment connection. Finite element predictions showed high agreement with experimental results. The findings highlight a clinically relevant criterion: implanto-plasty depth should not exceed the original thread height, as excessive wall reduction markedly compromises fatigue resistance and long-term mechanical reliability.

Verified
Journal Article
Open access
PDF file
ERESTEBAN PADULLÉS - ROIG
ESTEBAN PADULLÉS - ROIG
PSPablo Sevilla
Pablo Sevilla
Eugenio Velasco-OrtegaEugenio Velasco-Ortega
Eugenio Velasco-Ortega
MCMiguel Cerrolaza
Miguel Cerrolaza
DFDarcio Fonseca
Darcio Fonseca
Javier GilJavier Gil
Javier Gil
The increasing prevalence of peri-implantitis has led to a growing clinical use of implantoplasty, a procedure involving intraoral machining of the dental implant surface to remove biofilm. The absence of standardized clinical protocols may contribute to premature fatigue failure of dental implants. The present study aimed to evaluate the influence of machining depth on the cyclic mechanical behavior of dental implants. A total of 250 commercially pure grade 4 titanium dental implants were distributed into four groups according to machining depth: untreated (original), 0.2 mm, 0.4 mm, and 0.6 mm wall reduction. The implant system featured an internal connection with a thread height of 0.4 mm. Finite element analysis was performed for each machining depth to evaluate von Mises stress distribution and simulate fatigue behavior. The numerical models were validated through experimental fatigue testing using a servo-hydraulic MTS Bionix testing machine under ISO 14801:2016 conditions, showing a high correlation between simulated and experimental results (correlation coefficients > 0.9). The results indicated that maximum von Mises stresses were concentrated at the junction between the implant thread and the implant body. The fatigue limit of the untreated implants was approximately 351 N. Implants subjected to 0.4 mm machining exhibited a fatigue limit of 301 N, whereas lower fatigue limits were observed for 0.2 mm (255 N) and 0.6 mm (185 N) reductions. These findings suggest a significant mechanical effect of thread removal: 0.4 mm implantoplasty may provide improved fatigue performance compared to 0.2 mm, potentially due to reduced stress concentration at the thread–body junction. At high applied loads, fracture occurred in the coronal region of the implant, whereas at lower loads failure shifted to the implant–abutment connection. Although a good agreement between numerical and experimental results was observed, these findings should be interpreted with caution due to the in vitro testing conditions and the assumptions inherent to the finite element simulations. Therefore, while the results suggest that implantoplasty depth should not exceed the original thread height, further validation under clinically relevant conditions is required to confirm its impact on long-term mechanical reliability.

7 September 2026 in Materials
Verified
Journal Article
Open access
PDF file
DFDarcio Fonseca
Darcio Fonseca
Javier GilJavier Gil
Javier Gil
Over the past decade, the field of hard tissue replacement biomaterials has undergone a profound paradigm shift, evolving from simple bioinert structural supports into intelligent, multifunctional systems capable of actively driving bone tissue regeneration