17 research outputs found
Estudio comparativo del comportamiento celular temprano sobre superficies de circonia frente a cerámicas de silicato de litio reforzado con circonia
Introducción: Esta tesis doctoral tiene como propósito la valoración de un nuevo material CAD/CAM: el silicato de litio reforzado con circonia (ZLS) y su comparación con circonia (Y-TZP), considerado gold estándar en su uso como aditamento implantológico en restauraciones estéticas. Diversas publicaciones han analizado las propiedades mecánicas de ZLS, pero pocos estudios tratan de su comportamiento en contacto con tejidos blandos.
Hipótesis de trabajo: Se asume la igualdad de comportamiento celular en ambos materiales de estudio.
Objetivo: Evaluar la respuesta in vitro de fibroblastos gingivales humanos (HGFs) al ser cultivados sobre superficies de ZLS, Y-TZP y discos control de poliestireno.
Material y Método: Se realizó la caracterización de los discos de estudio a través de un análisis composicional, topográfico y de humectabilidad de superficie. Se compararon distintos parámetros citomorfométricos, conteo y esparcimiento celular temprana a las 24 horas. Se evaluó la citotoxicidad del material a través del análisis de la viabilidad celular por contacto directo con el material en tres tramos de tiempo: 24, 48 y 72 horas. Se cuantificó la secreción de colágeno tipo I por parte de las células a las 24 y 72 horas.
Resultados: La superficie de circonia estabilizada con itrio (Y-TZP) presentó un mayor número de células y éstas exhibieron parámetros citomorfométricos superiores con mayor cubrimiento del disco. Ambos materiales mostraron una moderada citotoxicidad en las primeras 24 horas, que se redujo no habiendo diferencias estadísticamente significativas a partir de las 48 horas, alcanzándose niveles biológicamente aceptables (>70% viabilidad) a las 72 horas. La secreción de colágeno no reveló superioridad de un material respecto a otro a las 24 horas, aunque Y-TZP fue significativamente superior a las 72 horas (p<0,001).
Conclusión: La superficie de Y-TZP genera una respuesta celular más favorable a nivel de conteo celular y esparcimiento sobre la superficie, con mayor viabilidad inicial a las 24 horas. La secreción de colágeno fue superior en Y-TZP a las 72 horas sin presentar diferencias en relación a ZLS a las 24 horas. Son necesario más estudios para poder afianzar estos hallazgos y poder extrapolar los resultados al ámbito clínico.
Palabras clave (DeCS): Porcelana Dental; Circonia; Silicatos; Pilares Dentales; CAD-CAM; Propiedades de superficie; Humectabilidad; Ensayo de Materiales; Fibroblastos; Supervivencia Celular; Colágeno Tipo I
Superficial characteristics of titanium after treatment of chorreated surface, passive acid, and decontamination with argon plasma
Background. Titanium is characterized by its biocompatibility, resistance to maximum stress, and fatigue and non-toxicity. The composition, surface structure, and roughness of titanium have a key and direct influence on the osseointegration processes when it is used in the form of dental implants. The objective of the present study is to characterize, at chemical, superficial, and biological levels, the result of the application of the sandblasted with large-grit and acid-etched (SLA) treatment consisting of coarse-grained and double-passivated acid blasting with subsequent decontamination with argon plasma on the surface of titanium implants type IV. (2) Methods. Four Oxtein® dental implants (Zaragoza, Spain) were investigated with the following coding: Code L63713T (titanium grade IV, 3.75 mm in diameter, and 13 mm in length). The surface of the implants was SLA type obtained from coarse-grained, double passivated acid, and decontaminated with argon plasma. The samples were in their sealed packages and were opened in our laboratory. The X-ray photoelectron spectroscopy (XPS) technique was used to characterize the chemical composition of the surface, and the scanning electronic microscope (SEM) technique was used to perform topographic surface evaluation. Cell cultures were also performed on both surfaces. (3) Results. The superficial chemical analysis of the studied samples presented the following components, approximately, expressed in atomic percentage: O: 39%; Ti: 18%; C: 39%; N: 2%; and Si: 1%. In the same way, the topographic analysis values were obtained in the evaluated roughness parameters: Ra: 1.5 μm ± 0.02%; Rq: 1.31 μm ± 0.33; Rz: 8.98 μm ± 0.73; Rp: 5.12 μm ± 0.48; Rv: 3.76 μm ± 0.51; and Rc: 4.92 μm ± 0.24. At a biological level, the expression of osteocalcin was higher (p < 0.05) on the micro-rough surface compared to that machined at 48 and 96 h of culture. (4) Conclusions. The data obtained in our study indicate that the total carbon content, the relative concentration of titanium, and the roughness of the treatment performed on the implants are in agreement with those found in the literature. Further, the roughness of the treatment performed on the implants throws a spongy, three-dimensional surface suitable for bone growth on it. The biological results found are compatible with the clinical use of the surface tested
Superficial characteristics of titanium after treatment of chorreated surface, passive acid, and decontamination with argon plasma
Background. Titanium is characterized by its biocompatibility, resistance to maximum stress, and fatigue and non-toxicity. The composition, surface structure, and roughness of titanium have a key and direct influence on the osseointegration processes when it is used in the form of dental implants. The objective of the present study is to characterize, at chemical, superficial, and biological levels, the result of the application of the sandblasted with large-grit and acid-etched (SLA) treatment consisting of coarse-grained and double-passivated acid blasting with subsequent decontamination with argon plasma on the surface of titanium implants type IV. (2) Methods. Four Oxtein® dental implants (Zaragoza, Spain) were investigated with the following coding: Code L63713T (titanium grade IV, 3.75 mm in diameter, and 13 mm in length). The surface of the implants was SLA type obtained from coarse-grained, double passivated acid, and decontaminated with argon plasma. The samples were in their sealed packages and were opened in our laboratory. The X-ray photoelectron spectroscopy (XPS) technique was used to characterize the chemical composition of the surface, and the scanning electronic microscope (SEM) technique was used to perform topographic surface evaluation. Cell cultures were also performed on both surfaces. (3) Results. The superficial chemical analysis of the studied samples presented the following components, approximately, expressed in atomic percentage: O: 39%; Ti: 18%; C: 39%; N: 2%; and Si: 1%. In the same way, the topographic analysis values were obtained in the evaluated roughness parameters: Ra: 1.5 μm ± 0.02%; Rq: 1.31 μm ± 0.33; Rz: 8.98 μm ± 0.73; Rp: 5.12 μm ± 0.48; Rv: 3.76 μm ± 0.51; and Rc: 4.92 μm ± 0.24. At a biological level, the expression of osteocalcin was higher (p < 0.05) on the micro-rough surface compared to that machined at 48 and 96 h of culture. (4) Conclusions. The data obtained in our study indicate that the total carbon content, the relative concentration of titanium, and the roughness of the treatment performed on the implants are in agreement with those found in the literature. Further, the roughness of the treatment performed on the implants throws a spongy, three-dimensional surface suitable for bone growth on it. The biological results found are compatible with the clinical use of the surface tested
In vitro comparative study of fibroblastic behaviour on polymethacrylate (PMMA) and lithium disilicate polymer surfaces
Polymethyl methacrylate (PMMA) and lithium disilicate are widely used materials in the dental field. PMMA is mainly used for the manufacture of removable prostheses; however, with the incorporation of CAD-CAM technology, new applications have been introduced for this material, including as a provisional implant attachment. Lithium disilicate is considered the gold standard for definitive attachment material. On the other hand, PMMA has begun to be used in clinics as a provisional attachment until the placement of a definitive one occurs. Although there are clinical studies regarding its use, there are few studies on cell reorganization around this type of material. This is why we carried out an in vitro comparative study using discs of both materials in which human gingival fibroblasts (HGFs) were cultured. After processing them, we analyzed various cellular parameters (cell count, cytoskeleton length, core size and coverage area). We analyzed the surface of the discs together with their composition. The results obtained were mostly not statistically significant, which shows that the qualities of PMMA make it a suitable material as an implant attachment
Comparison of cytomorphometry and early cell response of human gingival fibroblast (HGFs) between zirconium and new zirconia-reinforced lithium silicate ceramics
New zirconia-reinforced lithium silicate ceramics (ZLS) could be a viable alternative to zirconium (Y-TZP) in the manufacture of implantological abutments—especially in aesthetic cases—due to its good mechanical, optical, and biocompatibility properties. Although there are several studies on the ZLS mechanical properties, there are no studies regarding proliferation, spreading, or cytomorphometry. We designed the present study which compares the surface, cellular proliferation, and cellular morphology between Y-TZP (Vita YZ® T [Vita Zahnfabrik (Postfach, Germany)]) and ZLS (Celtra® Duo [Degudent (Hanau-Wolfgang, Germany)]). The surface characterization was performed with energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), and optical profilometry. Human gingival fibroblasts (HGFs) were subsequently cultured on both materials and early cellular response and cell morphology were compared through nuclear and cytoskeletal measurement parameters using confocal microscopy. The results showed greater proliferation and spreading on the surface of Y-TZP. This could indicate that Y-TZP continues to be a gold standard in terms of transgingival implant material: Nevertheless, more in vitro and in vivo research is necessary to confirm the results obtained in this study
Biocompatibility of Polymer and Ceramic CAD/CAM Materials with Human Gingival Fibroblasts (HGFs)
Four polymer and ceramic computer-aided design/computer-aided manufacturing
(CAD/CAM) materials from different manufacturers (VITA CAD-Temp (polymethyl methacrylate,
PMMA), Celtra Duo (zirconia-reinforced lithium silicate ceramic, ZLS), IPS e.max CAD (lithium
disilicate (LS2)), and VITA YZ (yttrium-tetragonal zirconia polycrystal, Y-TZP)) were tested to evaluate
the cytotoxic effects and collagen type I secretions on human gingival fibroblasts (HGFs). A total of
160 disc-shaped samples (Ø: 10 ± 2 mm; h: 2 mm) were milled from commercial blanks and blocks.
Direct-contact cytotoxicity assays were evaluated at 24, 48, and 72 h, and collagen type I (COL1)
secretions were analysed by cell-based ELISA at 24 and 72 h. Both experiments revealed statistically
significant differences (p < 0.05). At 24 and 48 h of contact, cytotoxic potential was observed for all
materials. Later, at 72 h, all groups reached biologically acceptable levels. LS2 showed the best results
regarding cell viability and collagen secretion in all of the time evaluations, while Y-TZP and ZLS
revealed intermediate results, and PMMA exhibited the lowest values in both experiments. At 72 h,
all groups showed sharp decreases in COL1 secretion regarding the 24-h values. According to the
results obtained and the limitations of the present in vitro study, it may be concluded that the ceramic
materials revealed a better cell response than the polymers. Nevertheless, further studies are needed
to consolidate these findings and thus extrapolate the results into clinical practic
Benefits of Residual Aluminum Oxide for Sand Blasting Titanium Dental Implants: Osseointegration and Bactericidal Effects
Objectives. The purpose of this work was to determine the influence of residual alumina
after sand blasting treatment in titanium dental implants. This paper studied the effect of alumina on
physico-chemical surface properties, such as: surface wettability, surface energy. Osseointegration
and bacteria adhesion were determined in order to determine the effect of the abrasive particles.
Materials and Methods. Three surfaces were studied: (1) as-received, (2) rough surface with residual
alumina from sand blasting on the surface and (3) with the same roughness but without residual
alumina. Roughness was determined by white light interferometer microscopy. Surface wettability
was evaluated with a contact angle video-based system and the surface free energy by means of
Owens and Wendt equation. Scanning electron microscopy equipped with microanalysis was used to
study the morphology and determine the chemical composition of the surfaces. Bacteria (Lactobacillus
salivarius and Streptococcus sanguinis) were cultured in each surface. In total, 110 dental implants
were placed into the bone of eight minipigs in order to compare the osseointegration. The percentage
of bone-to-implant contact was determined after 4 and 6 weeks of implantation with histometric
analysis. Results. The surfaces with residual alumina presented a lower surface free energy than
clean surfaces. The in vivo studies demonstrated that the residual alumina accelerated bone tissue
growth at different implantation times, in relation to clean dental implants. In addition, residual
alumina showed a bactericidal effect by decreasing the quantity of bacteria adhering to the titanium.
Conclusions. It is possible to verify the benefits that the alumina (percentages around 8% in weight)
produces on the surface of titanium dental implants. Clinical relevance. Clinicians should be aware
of the benefits of sand-blasted alumina due to the physico-chemical surface changes demonstrated in
in vivo tests
Dimensional Changes in the Alveolus after a Combination of Immediate Postextraction Implant and Connective Grafting and/or Socket Shield Techni
: Immediate implant placement protocols after dental extraction have enabled a reduction in
surgical phases. This procedure has increased patient satisfaction and similar survival rates to late
implant placement procedures. However, placing an implant immediately after dental extraction
does not counteract the physiological remodeling of alveolar bone. For this reason, additional surgical
techniques have been developed, such as the placement of a connective tissue graft (CTG) or the
socket shield technique (SST). Dimensional changes in the peri-implant tissues were observed after
placement of immediate implants following the extraction and CTG and/or SST. A total of 26 surgical
interventions were carried out in which dimensional change variables of peri-implant tissues were
analyzed. The preoperative state and immediate postoperative situation were compared with the
situation after one year. Measurements were taken at 3, 5, and 7 mm from the gingival margin
and analyzed in this CBCT radiological study (Planmeca Promax 3D). The implant platform was
used as a reference point for the measurement of changes in alveolar crest height. One year after
performing either of the two techniques (CTG and/or SST), a significant increase in the gingiva
thickness and vestibular cortex occurred at 5 mm (0.65 ± 1.16 mm) and 7 mm (0.95 ± 1.45 mm)
from the gingival margin. Additionally, an increase in thickness of palatal bone was registered at
3 mm (0.48 ± 0.90 mm). The graft placement group showed an increase in thickness of peri-implant
tissue in the vestibular area after one year, although CTG and SST groups were clinically similar. The
implementation of SST revealed promising results regarding the buccal thickness of hard and soft
tissues after one year. A significant increase in vestibular cortical bone thickness, as well as the overall
mucosa thickness and buccal bone at 3 mm from the gingival margin, was observed. A significant
reduction in the distance from the bone crest to the platform was detected in both techniques. Both
techniques (CTG and SST) are appropriate to provide sufficient volume to peri-implant tissues in the
vestibular area of anterior maxillary implants. Some limitations were detected, such as the lack of an
aesthetic analysis or small sample size, so results should be interpreted with caution. Future studies
are necessary to further evaluate the long-term predictability of these techniques
Influence of Three Dental Implant Surfaces on Cell Viability and Bone Behavior. An In Vitro and a Histometric Study in a Rabbit Model
The chemical composition and the surface characteristics of dental implants are factors that have a decisive effect on the osseointegration process. The surface characterization at the compositional and topographic level of three dental implants available in the market was performed with different surface treatments: (1) sandblasted and acid etched surface (SLA), (2) hydroxyapatite (HA) and tricalcium phosphate (TCP) blasted surface (HA/TCP), and (3) HA-blasted and non-etching acid washed surface (HA + AW). In addition, an in vitro viability study of MG-63 osteoblast cells was performed with a JC-1 test. To complete the study, an in vivo study was conducted in New Zealand rabbits. The study analyzed the histometric characteristics of the bone formed around the implants at the level of area, volume, bone density, accumulated bone density, and bone–implant contact (BIC). The rabbits were sacrificed at 6 weeks after implants were placed in the tibial metaphysis.
No statistically significant differences were observed at the level of cell viability or histometric parameters between the different study groups (p > 0.05). SLA and HA/TCP surfaces were the ones that obtained a higher BIC value. Taking into account the limitations of this study, it can be concluded that the different implant surfaces analyzed favor a good bone response
Superficial Characteristics of Titanium after Treatment of Chorreated Surface, Passive Acid, and Decontamination with Argon Plasma
(1) Background. Titanium is characterized by its biocompatibility, resistance to maximum stress, and fatigue and non-toxicity. The composition, surface structure, and roughness of titanium have a key and direct influence on the osseointegration processes when it is used in the form of dental implants. The objective of the present study is to characterize, at chemical, superficial, and biological levels, the result of the application of the sandblasted with large-grit and acid-etched (SLA) treatment consisting of coarse-grained and double-passivated acid blasting with subsequent decontamination with argon plasma on the surface of titanium implants type IV. (2) Methods. Four Oxtein® dental implants (Zaragoza, Spain) were investigated with the following coding: Code L63713T (titanium grade IV, 3.75 mm in diameter, and 13 mm in length). The surface of the implants was SLA type obtained from coarse-grained, double passivated acid, and decontaminated with argon plasma. The samples were in their sealed packages and were opened in our laboratory. The X-ray photoelectron spectroscopy (XPS) technique was used to characterize the chemical composition of the surface, and the scanning electronic microscope (SEM) technique was used to perform topographic surface evaluation. Cell cultures were also performed on both surfaces. (3) Results. The superficial chemical analysis of the studied samples presented the following components, approximately, expressed in atomic percentage: O: 39%; Ti: 18%; C: 39%; N: 2%; and Si: 1%. In the same way, the topographic analysis values were obtained in the evaluated roughness parameters: Ra: 1.5 μm ± 0.02%; Rq: 1.31 μm ± 0.33; Rz: 8.98 μm ± 0.73; Rp: 5.12 μm ± 0.48; Rv: 3.76 μm ± 0.51; and Rc: 4.92 μm ± 0.24. At a biological level, the expression of osteocalcin was higher (p < 0.05) on the micro-rough surface compared to that machined at 48 and 96 h of culture. (4) Conclusions. The data obtained in our study indicate that the total carbon content, the relative concentration of titanium, and the roughness of the treatment performed on the implants are in agreement with those found in the literature. Further, the roughness of the treatment performed on the implants throws a spongy, three-dimensional surface suitable for bone growth on it. The biological results found are compatible with the clinical use of the surface tested