Jose N Gil

Publications of Jose N Gil

• Histomorphologic and bone-to-implant contact evaluation of dual acid-etched and bioceramic grit-blasted implant surfaces: an experimental study in dogs.

  Authors: Marcelo Suzuki, Marcia V M Guimaraes, Charles Marin, Rodrigo Granato, Carlos A O Fernandes, Jose N Gil, Paulo G Coelho

  Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons. 08/2010; 68(8):1877-83.

  The objective of this study was to histologically evaluate a bioceramic grit-blasted and acid-etched surface (presenting calcium and phosphorous incorporation within the surface and its oxide) versusThe objective of this study was to histologically evaluate a bioceramic grit-blasted and acid-etched surface (presenting calcium and phosphorous incorporation within the surface and its oxide) versus a dual acid-etched (no calcium and phosphorous, control) moderately rough implant surface in a dog tibia model. Implants 3 x 10 mm were placed bilaterally along the proximal tibia of 6 Doberman dogs and remained for 2 and 4 weeks in vivo. After the dogs were euthanized, the implants were nondecalcified processed to approximately 30-microm-thick plates. Transmitted light optical microscopy was used to evaluate healing patterns and bone-to-implant contact. Statistical analysis was performed by 1-way analysis of variance at the 95% level of significance and by Tukey post hoc tests. At 2 weeks, histologic evaluation showed woven bone formation throughout the perimeter of both implant surfaces. However, replacement of woven bone by lamellar bone was only observed around the test surface at 4 weeks in vivo. No significant differences in bone-to-implant contact were observed for the different groups (P > .27). Despite nonsignificant differences between bone-to-implant contact for the different surfaces and times in vivo, higher degrees of bone organization were observed for the test implants. Biomechanical testing is warranted to verify potential differences in biomechanical fixation effectiveness between surfaces.

• Effect of surface modifications on early bone healing around plateau root form implants: an experimental study in rabbits.

  Authors: Marcelo Suzuki, Monica D Calasans-Maia, Charles Marin, Rodrigo Granato, Jose N Gil, Jose M Granjeiro, Paulo G Coelho

  Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons. 07/2010; 68(7):1631-8.

  The objective of the present study was to evaluate the biomechanical fixation and bone-to-implant contact (BIC) of plateau root form implants of varied surfaces. Plateau root form implants, 3.5 mm inThe objective of the present study was to evaluate the biomechanical fixation and bone-to-implant contact (BIC) of plateau root form implants of varied surfaces. Plateau root form implants, 3.5 mm in diameter, 8 mm in length, with 4 surfaces (n = 16 each)--machined, alumina-blasted/acid-etched, alumina-blasted/acid-etched plus nanothickness bioceramic coating, and plasma-sprayed calcium-phosphate--were used. They were bilaterally placed at the distal femur of 16 New Zealand rabbits and remained in place for 2 and 4 weeks in vivo. After euthanizing the rabbits, the implants were subjected to torque to interface fracture and were subsequently processed as nondecalcified approximately 30-microm-thickness slides for histomorphologic analysis and BIC determination. Statistical analysis was performed using analysis of variance at the 95% level of significance, considering implantation time and implant surface as independent variables and the torque-to-interface fracture and BIC as dependent variables. The torque-to-interface fracture was significantly affected by the implant surface (P < .001) but was not affected by the implantation time (P > .20). The implantation time and implant surface had significant effects on the BIC (P < .04 and P < .001, respectively). The greatest torque-to-interface fracture and BIC was observed for the plasma-sprayed calcium-phosphate. The implant surface significantly influenced early bone healing around plateau root form implants.

• Biomechanical and histomorphometric analysis of etched and non-etched resorbable blasting media processed implant surfaces: an experimental study in dogs.

  Authors: Charles Marin, Rodrigo Granato, Marcelo Suzuki, Malvin N Janal, Jose N Gil, Carlos Nemcovsky, Estevam A Bonfante, Paulo G Coelho

  Journal of the mechanical behavior of biomedical materials. 07/2010; 3(5):382-91.

  This study characterized the interplay between topography/chemistry and early bone response of etched and no-etched resorbable blasted media (RBM) processed surfaces. Screw-root form Ti-6Al-4VThis study characterized the interplay between topography/chemistry and early bone response of etched and no-etched resorbable blasted media (RBM) processed surfaces. Screw-root form Ti-6Al-4V implants treated with alumina blasting/acid-etching (AB/AE), RBM alone (RBM), and RBM + acid-etching (RBMa) were evaluated. The surface was characterized by scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. Implants placed in the tibia of dogs remained 3 and 5 weeks in vivo. Following euthanasia, half of the specimens were torqued to interface failure and the remaining subjected to bone-to-implant contact (BIC) and bone area fraction occupied (BAFO) between threads evaluation. The AB/AE surface was rougher than the RBM and RBMa. Higher levels of calcium and phosphorous were observed for the RBM surface compared to the RBMa. No significant differences were observed in torque, BIC, and BAFO between surfaces. Woven bone formation at 3 weeks and its initial replacement by lamellar bone at 5 weeks were observed around all implants' surfaces.

• Biomechanical evaluation of endosseous implants at early implantation times: a study in dogs.

  Authors: Paulo G Coelho, Rodrigo Granato, Charles Marin, Estevam A Bonfante, Jose N O Freire, Malvin N Janal, Jose N Gil, Marcelo Suzuki

  Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons. 07/2010; 68(7):1667-75.

  This study tested the null hypothesis that differences in surgical instrumentation, macrogeometry, and surface treatment imposed by different implant systems do not affect early biomechanicalThis study tested the null hypothesis that differences in surgical instrumentation, macrogeometry, and surface treatment imposed by different implant systems do not affect early biomechanical fixation in a canine mandible model. The lower premolars of 6 beagle dogs were extracted and the ridges allowed to heal for 8 weeks. Thirty-six (n = 12 each group) implants were bilaterally placed, remaining for 1 and 3 weeks in vivo. The implant groups were as follows: group 1, Ti-6Al-4V with a dual acid-etched surface with nanometer scale discrete crystalline deposition (Nanotite; Certain Biomet-3i, West Palm Springs, FL); group 2, Ti-6Al-4V with a titanium oxide-blasted fluoride-modified surface chemistry (Osseospeed 4.0 S; Astra Tech, Mölndal, Sweden); group 3: Ti-6Al-4V with a bioceramic microblasted surface (Ossean; Intra-Lock International, Boca Raton, FL). Following euthanasia, implants were torqued to interface failure and histologically evaluated. General linear modeling (ANOVA) at 95% level of significance was performed. Histology showed that interfacial bone remodeling and initial woven bone formation were observed around all implant groups at 1 and 3 weeks. Torque values were significantly affected by time in vivo, implant group, and their interaction (P = .016, P < .001, and P = .001, respectively). Regarding torque values, group 3, group 2, and group 1 ranked highest, intermediate, and lowest, respectively. Early biomechanical fixation at 1 and 3 weeks was affected by surgical instrumentation, macrogeometry, and surface treatment present for one of the implant systems tested. The null hypothesis was rejected.

• Histomorphologic and histomorphometric evaluation of various endosseous implant healing chamber configurations at early implantation times: a study in dogs.

  Authors: Charles Marin, Rodrigo Granato, Marcelo Suzuki, Jose N Gil, Malvin N Janal, Paulo G Coelho

  Clinical oral implants research. 06/2010; 21(6):577-83.

  The objective of this study was to evaluate the early healing of endosseous implants presenting various healing chamber configurations in a beagle dog mandible model. The four premolars of 12 beagleThe objective of this study was to evaluate the early healing of endosseous implants presenting various healing chamber configurations in a beagle dog mandible model. The four premolars of 12 beagle dogs were extracted and allowed to heal for a period of 8 weeks. Implants allowing six different healing chamber configurations were placed in each dog (three per side, six configurations per dog). The animals were sacrificed after 3 and 5 weeks in vivo (n=6 per time in vivo), and the implants were non-decalcified processed to slides of approximately 30 microm thickness. Bone-to-implant contact (BIC) and bone area fraction occupied (BAFO) within the healing chamber were quantified. Statistical analysis was performed by a GLM ANOVA model at 5% significance level. Osseointegration and healing with woven bone filling throughout all healing chambers was observed. Replacement of woven bone by lamellar bone showing primary osteonic structures was observed at 5 weeks. BIC was significantly affected by healing chamber configuration (P<0.001) and was not affected by time in vivo (P>0.42) at 3 and 5 weeks in vivo. BAFO was not affected by healing chamber configuration (P>0.14) however significantly increased over implantation time (P<0.001). Regardless of healing chamber design and dimensions considered, healing allowed the devices osseointegration. However, healing chamber configuration significantly affected osseointegration measurable parameters such as BIC.

• Thin Bioactive Ceramic-Coated Alumina-Blasted/Acid-Etched Implant Surface Enhances Biomechanical Fixation of Implants: An Experimental Study in Dogs.

  Authors: Rodrigo Granato, Charles Marin, Jose N Gil, Sung-Kiang Chuang, Thomas B Dodson, Marcelo Suzuki, Paulo G Coelho

  Clinical implant dentistry and related research. 09/2009;

  ABSTRACT Background: Thin bioceramic coatings have been regarded as potential substitutes for plasma-sprayed hydroxyapatite coatings. Purpose: This study tested the hypothesis that a thin bioactiveABSTRACT Background: Thin bioceramic coatings have been regarded as potential substitutes for plasma-sprayed hydroxyapatite coatings. Purpose: This study tested the hypothesis that a thin bioactive ceramic coating deposition on an alumina-blasted/acid-etched (AB/AE) surface would positively affect the biomechanical fixation and bone-to-implant contact (BIC) of plateau root form implants. Materials and Methods: Implants of two different lengths (i.e., 4.5 x 11 mm long, n = 36) and 4.5 x 6 mm (short, n = 36) and two different surfaces, that is, control (AB/AE) and test (AB/AE + 300 - 500 nm bioactive ceramic coating), were placed in the proximal tibiae of six beagle dogs. The implants were retrieved for analyses 2 and 4 weeks after placement. The implants in bone specimens were subjected to torque loads until a 10% drop of the maximum torque was recorded. The specimens were evaluated under optical microscopy for bone morphology and percent BIC. Statistical analysis was performed by a generalized linear mixed effects analysis of variance model and statistical significance set at p < 0.05. Results: Significantly higher torque-to-interface fracture levels for test surface groups of both lengths when compared to control surfaces were observed. No significant difference in BIC was observed between test and control implants of equal length. Histomorphological analysis showed higher degrees of bone organization between the plateaus of test implant surfaces at both implantation times. Conclusion: Because the presence of a thin bioactive ceramic coating on the surface did not affect BIC, but positively affected implant biomechanical fixation, the hypothesis was partially validated.

• Early Bone Healing around Different Implant Bulk Designs and Surgical Techniques: A Study in Dogs.

  Authors: Paulo G Coelho, Marcelo Suzuki, Marcia V M Guimaraes, Charles Marin, Rodrigo Granato, Jose N Gil, Robert J Miller

  Clinical implant dentistry and related research. 05/2009;

  ABSTRACT Purpose: To evaluate the bone healing response to different implant root shape designs in a dog model. Materials and Methods: Three by eight millimeter screw-type short-pitch (SP) andABSTRACT Purpose: To evaluate the bone healing response to different implant root shape designs in a dog model. Materials and Methods: Three by eight millimeter screw-type short-pitch (SP) and large-pitch (LP) implants (Intra-Lock International, Boca Raton, FL, USA), and 4.5 x 6 mm plateau (P) implants (Bicon LLC, Boston, MA, USA) were placed along the proximal tibia of six dogs for 2 and 4 weeks. The combination of implant design and final osteotomy drilling resulted in healing chambers for the LP and P implants. The implants were nondecalcified processed to plates of approximately 30-microm thickness and were evaluated by optical microscopy for healing patterns and bone-to-implant contact (BIC). One-way analysis of variance at 95% level of significance and Tukey's test were utilized for multiple comparisons among the groups' BIC. Results: Microscopy showed a approximately 150-microm region of newly deposited bone along the whole perimeter of SP implants, near the edge of the LP implant threads, and plateau tips for P implants. Rapid woven bone formation and filling was observed in regions where surgery and implant design resulted in healing chambers. No significant differences in BIC were observed (p > .75). Conclusions: Different implant design/surgical protocol resulted in varied bone healing patterns. However, the BIC and bone morphology evolution between implant designs were comparable. Regardless of the combination between implant design and final osteotomy drilling, bone morphology evolution from 2 to 4 weeks was comparable.

• Biomechanical and histomorphometric evaluation of a thin ion beam bioceramic deposition on plateau root form implants: An experimental study in dogs.

  Authors: Rodrigo Granato, Charles Marin, Marcelo Suzuki, Jose N Gil, Malvin N Janal, Paulo G Coelho

  Journal of biomedical materials research. Part B, Applied biomaterials. 01/2009;

  The aim of this study was to evaluate the biomechanical fixation, bone-to-implant contact, and bone morphology of an ion beam assisted deposition of a 300-500 nm thick Ca- and P-based bioceramicThe aim of this study was to evaluate the biomechanical fixation, bone-to-implant contact, and bone morphology of an ion beam assisted deposition of a 300-500 nm thick Ca- and P-based bioceramic surface on a previously alumina-blasted/acid-etched Ti-6Al-4V implant surface in a dog model. Materials and Methods: Thirty-six 4.5 x 11 mm plateau root form implants, control (alumina-blasted/acid-etched-AB/AE) and test groups (AB/AE+300-500 nm bioceramic coating, Nanotitetrade mark) were placed along a proximal tibia of six beagle dogs remaining for 2 and 4 weeks (n = 3 animals per implantation time). Following euthanization, the implants were torqued to interface fracture at approximately 0.196 radians/sec until a 10% maximum load drop was detected. The implants in bone were nondecalcified processed to approximately 30 mum thickness slides for histomorphologic and bone-to-implant contact (BIC) assessment. Statistical analyses for torque to interface fracture were performed using a mixed model ANOVA, and BIC was evaluated by the chi2 test at 95% level of significance. Results: At 4 weeks, significantly higher torque to interface fracture was observed for the Test implant surface. Histomorphologic analysis showed higher degrees of bone organization for test implants compared to control at 2 and 4 weeks. Significantly higher BIC was observed at 4 weeks compared to 2 weeks (no statistical differences between control and test implants). Conclusion: The higher torque to interface fracture and increased bone maturity obtained in this study support that the surface modification comprising a 300-500 nm Ca- and P-based bioceramic coating positively influenced healing around pleateau root form implants. (c) 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2009.

• Removal Torque and Histomorphometric Evaluation of Bioceramic Grit-Blasted/Acid-Etched and Dual Acid-Etched Implant Surfaces: An Experimental Study in Dogs.

  Authors: Charles Marin, Rodrigo Granato, Marcelo Suzuki, Jose N Gil, Adriano Piattelli, Paulo G Coelho

  Journal of periodontology. 10/2008; 79(10):1942-1949.

  Background: Surface modifications to dental implants have been used in an attempt to accelerate the osseointegration process. The objective of this study was to biomechanically/histomorphometricallyBackground: Surface modifications to dental implants have been used in an attempt to accelerate the osseointegration process. The objective of this study was to biomechanically/histomorphometrically evaluate a bioceramic grit-blasted and acid-etched surface (BGB/AA; test) versus a dual acid-etched implant surface (control) in a beagle dog model. Methods: Control and BGB/AA implants were subjected to a series of physicochemical characterization tools, including scanning electron microscopy (SEM), atomic force microscopy (AFM), and auger photoelectron spectroscopy (APS). The animal model included the placement of 72 implants along the proximal tibiae of six beagle dogs, which remained in place for 2 or 4 weeks. After euthanization, half of the specimens were biomechanically tested (removal torque), and the other half was non-decalcified processed to slides of approximately 30 mum thickness for histomorphologic and histomorphometric (percentage of bone-to-implant contact [%BIC]) evaluation. Analysis of variance at the 95% confidence level and the Tukey post hoc test were used for multiple comparisons. Results: SEM and AFM showed that surface microtextures were qualitatively and quantitatively different and that the BGB/AA surface presented higher submicrometer average roughness values (R(a)) and root mean square (RMS) values compared to control surfaces. Ca and P were detected at the BGB/AA surface by APS. Higher degrees of bone organization were observed along the perimeter of the BGB/AA surface compared to control, despite the non-significant differences in %BIC between the surfaces (P >0.25). Significantly higher removal torque was observed for the BGB/AA implants at both time periods (P <0.0001). Conclusion: According to the biomechanical and histomorphologic results, early biomechanical fixation was positively affected by the BGB/AA surface compared to the dual-acid etched surface.

• Bone mineral apposition rates at early implantation times around differently prepared titanium surfaces: a study in beagle dogs.

  Authors: Paulo G Coelho, Jose N Freire, Rodrigo Granato, Charles Marin, Estevam A Bonfante, Jose N Gil, Sung-Kiang Chuang, Marcelo Suzuki

  The International journal of oral & maxillofacial implants. 26(1):63-9.

  This study evaluated the bone mineral apposition rate (MAR) at the bone-implant interface region of alumina-blasted/acid-etched (AB/AE), plasma-sprayed hydroxyapatite (PSHA), and nanometric-scaleThis study evaluated the bone mineral apposition rate (MAR) at the bone-implant interface region of alumina-blasted/acid-etched (AB/AE), plasma-sprayed hydroxyapatite (PSHA), and nanometric-scale bioceramic-coated surfaces at early implantation times in a dog tibia model. Implants (n = 12 per group) with three different surfaces-AB/AE, PSHA, and a bioceramic coating in the 300- to 500-nm thickness range-were placed bilaterally along the proximal tibiae of six male beagles. Implants remained for 3 and 5 weeks in vivo. Ten and 2 days prior to euthanization, calcein green and oxytetracycline were administered for bone labeling. Following euthanization, the limbs were retrieved by sharp dissection and the implants and bone were processed nondecalcified into ~30-Μm-thick sections along the implant long axis. MAR was measured by the distance between bone labels over time at the interface region (to 0.5 mm from the implant surface) and at regions > 3 mm from the implant surface (remote site). A generalized linear mixed-effects analysis of variance model was conducted with significance levels set at .05. Irrespective of implant surface, the MAR at the interface region was significantly higher than the MAR at the remote site. Significant MAR differences in the interface region were observed between the different surfaces (PSHA > AB/AE > nano). Bone kinetics during early healing stages were influenced by implant surface modifications.