Elton Zenóbio | Pucminas-Brazil - Academia.edu (original) (raw)

Papers by Elton Zenóbio

The journal of contemporary dental practice, 2015

Some surface treatments performed on titanium can alter the composition of salivary pellicle form... more Some surface treatments performed on titanium can alter the composition of salivary pellicle formed on this abiotic surface. Such treatments modify the titanium's surface properties and can promote higher adsorption of proteins, which allow better integration of titanium to the biotic system. This study aimed to evaluate the interactions between salivary proteins and titanium disks with different surface treatments. Machined titanium disks (n = 48) were divided into four experimental groups (n = 12), according to their surface treatments: surface polishing (SP); acid etching (A); spot-blasting plus acid etching (SB-A); spot-blasting followed by acid etching and nano-functionalization (SB-A-NF). Titanium surfaces were characterized by surface roughness and scanning electron microscopy (SEM). Specimens were incubated with human saliva extracted from submandibular and sublingual glands. Total salivary protein adsorbed to titanium was quantified and samples were submitted to western...

World Journal of Orthopedics, 2015

To assess the failure and bone-to-implant contact rate of dental implants placed on osteoporotic ... more To assess the failure and bone-to-implant contact rate of dental implants placed on osteoporotic subjects.

Clinical Implant Dentistry and Related Research, 2010

Objective: The aim of this human study was to evaluate the radiation doses in the buccal cavity a... more Objective: The aim of this human study was to evaluate the radiation doses in the buccal cavity and face, during panoramic, spiral conventional tomography, and helicoidal computerized tomography exams.

BioMed Research International, 2014

Several histologic studies regarding peri-implant soft tissues and biological width around dental... more Several histologic studies regarding peri-implant soft tissues and biological width around dental implants have been done in animals. However, these findings in human peri-implant soft tissues are very scarce. Therefore, the aim of this case series was to compare the biological width around unloaded one-and two-piece implants retrieved from human jaws. Eight partially edentulous patients received 2 test implants in the posterior mandible: one-piece (solid implants that comprise implant and abutment in one piece) and two-piece (external hexagon with a healing abutment) implants. After 4 months of healing, the implants and surrounding tissue were removed for histologic analysis. The retrieved implants showed healthy peri-implant bone and exhibited early stages of maturation. Marginal bone loss, gaps, and fibrous tissue were not present around retrieved specimens. The biologic width dimension ranged between 2.55 ± 0.16 and 3.26 ± 0.15 to one-and two-piece implants, respectively ( < 0.05). This difference was influenced by the connective tissue attachment, while sulcus depth and epithelial junction presented the same dimension for both groups ( > 0.05). Within the limits of this study, it could be shown that two-piece implants resulted in the thickening of the connective tissue attachment, resulting in the increase of the biological width, when compared to one-piece implants.

Radiation Measurements, 2000

In diagnostic radiology, the radiation interaction probability in matter is a strong function of ... more In diagnostic radiology, the radiation interaction probability in matter is a strong function of the X-ray energy. The knowledge of the X-ray energy spectral distribution allows optimizing the radiographic imaging system in order to obtain high quality images with as low as reasonably achievable patient doses. In this study, transmitted X-ray spectra through dentin and enamel that are existing materials

Cadernos de Saúde Pública, 2007

Oral and Maxillofacial Surgery, 2011

Background Several studies have demonstrated the application of mini-implants in the orthodontic ... more Background Several studies have demonstrated the application of mini-implants in the orthodontic treatment as anchorage during the retraction movement of the anterior teeth. Purpose This study was designed to evaluate the mass retraction movement of the anterior upper teeth using orthodontic mini-implants as anchorage. Materials and methods Nine patients with class I malocclusion and Angle's class II, needing extractions of the upper first premolars, were enrolled in this case series. The retraction was performed using sliding mechanics and orthodontic anchorage on mini-implants. Measures were taken by initial and final cephalometric X-rays of the retraction movement to evaluate whether the mini-implants remained stationary and displacements of the incisors and the upper first premolars. Results Out of 18 mini-implants, 8 mesialized (0.45 mm, average) and 3 extruded (0.14 mm, average). The upper incisors were retracted on the average of 4.21 mm, extruded 0.33 mm, and tipped 10.3°. There were no statistical significant modifications in the placement of the posterior teeth.

Transplantation, 2008

Background. The results from reports analyzing the occurrence of gingival overgrowth (GO) induced... more Background. The results from reports analyzing the occurrence of gingival overgrowth (GO) induced by tacrolimus are controversial. In addition, the role of pharmacological and periodontal variables on the development and severity of GO have not been well-established. Therefore, the aim of the present study was to determine the effect of potential risk variables for GO in a Brazilian population comprising renal transplant recipients medicated with tacrolimus in the absence of calcium channel blockers. Materials and Methods. Demographic, pharmacological, and periodontal data, recorded from 125 subjects selected to participate in the study, was analyzed with the use of the independent sample t test, the chi-squared statistic, or Mann-Whitney test. The effects of risk variables on GO scores were subsequently examined using multivariate regression analysis and general linear model. Results. The prevalence of clinically significant GO (Ն30%) in the study population was of 7.25%. These subjects showed greater averages of plaque scores (Pϭ0.0043) as well as papillary bleeding index (Pϭ0.0026) when compared to subjects with GO Ͻ30%. Papillary bleeding index, time since transplant and azathioprine dosage were significant in the univariate and multivariate models (adjusted R 2 ϭ43.8%), whereas plaque index was significant only in the univariate model.

Journal of Radioanalytical and Nuclear Chemistry, 2011

The present study determined the organic and inorganic composition of human enamel and dentin. Th... more The present study determined the organic and inorganic composition of human enamel and dentin. The instrumental neutron activation analysis, inductivelycoupled plasma spectrometer, thermogravimetric and differential thermal analysis and X-ray diffraction analysis applied were and performed in the Nuclear Technology Development Centre (CDTN) and Elemental Analysis in the Department of Chemistry of the Federal University of Pernambuco, Brazil. The coronal dentin and enamel were separated from dentin mechanically (1) and by wear (2). The analyses were effective and led to the identification of the main elements present in enamel and dentin: Ca, Na, Cl, Zn, P, Mg, N, C, H, O. There was no contamination of samples of enamel or dentin in either separation technique; however, with separation technique 1, lower percentages of mainly Ca (7.25%) and O (15.16%) components were detected in dentin compared with technique 2.

Journal of Periodontology, 2010

Background: This prospective and controlled histologic study evaluates the impact of smoking on b... more Background: This prospective and controlled histologic study evaluates the impact of smoking on bone-to-implant contact, the bone density in the threaded area, and the bone density outside the threaded area around microimplants with anodized surface retrieved from human jaws.

Journal of Oral Science, 2007

The aims of this study were to compare nitric oxide (NO) levels in stimulated whole saliva from i... more The aims of this study were to compare nitric oxide (NO) levels in stimulated whole saliva from individuals with and without generalized chronic periodontitis (GCP), and to evaluate correlations between these levels with a clinical diagnostic parameter. According to specific criteria, 30 individuals were divided into three groups: one comprising individuals without periodontitis (GC), a second comprising individuals with moderate GCP (GM), and a third comprising individuals with advanced GCP (GA). Samples were collected and NO levels measured. NO in the GCP group (GM: 7.78 µM; GA: 15.79 µM) was higher than in the GC group (5.86 µM). NO levels in the GA group were significantly higher (P < 0.0001) than in the GC group, and could also differentiate (P < 0.0001) the moderate and advanced forms of the disease. In addition, positive correlations between NO level and the number of teeth with a probing depth of ≥ 4 mm (r = 0.54) and ≥ 7 mm (r = 0.68) were observed. In conclusion, NO levels are elevated in individuals with GPC and are correlated with a periodontal clinical parameter. These results reveal that this form of periodontal disease and its severity are related to salivary nitrite concentration, indicating that NO may serve as a potential biological marker for detection and/or monitoring of GCP. (J. Oral Sci. 49, [271][272][273][274][275][276] 2007)

Journal of Oral Implantology, 2007

The aim of this study was to evaluate the microbiota and surface of failed titanium dental implan... more The aim of this study was to evaluate the microbiota and surface of failed titanium dental implants from 4 manufacturers. Twelve mobile dental implants were retrieved from 10 smokers after 3 to 10 years of functional loading. Before implant removal, microbial samples were taken and evaluated using polymerase chain reaction. After implant removal, analyses of the failed implant surfaces were performed using scanning electron microscopy and energy-dispersive spectrometer x-ray. Periodontal pathogens such as Aggregactibacter actinomycetemcomitans, Campylobacter rectus, Eikenella corrodens, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, and Treponema denticola were detected in all implants in different proportions. Surface analysis showed varying degrees of surface roughness between the samples and the presence of proteinaceous material, appearing mainly as dark stains. Foreign carbon, oxygen, sodium, calcium, aluminum, and silicon elements were also found. Although no material-related causes of implant failure were detected, several periodontal pathogens were identified independently of the surface topography or manufacturer.

Clinical Oral Investigations, 2012

Since in a previous study we encountered a subject with an unusual split MG2 banding pattern, the... more Since in a previous study we encountered a subject with an unusual split MG2 banding pattern, the aim of this study was to investigate the molecular basis of this observation. Submandibular/sublingual secretion was collected under resting and stimulated conditions and examined on Western blots probed with anti-MG2 antibodies or on gels stained with periodic acid-Schiff reagent. Genomic DNA was isolated and the N-, tandem repeat (TR), and C-terminal regions of MUC7 were amplified by PCR since MG2 is known to display a genetic polymorphism. Although the typical appearance of MG2 on blots and gels is a single 180 kDa band, salivary secretions from the subject exhibited doublet immunoreactive bands of approximately 180 and 125 kDa. Additionally, under resting conditions the 180 kDa band was predominant whereas upon stimulation the 125 kDa band became predominant. Genomic DNA analysis showed that MUC7 in the individual with split MG2 bands was not truncated and that the MUC7 genotype in this individual was (6/6) where both alleles encoded six TRs. The MG2 split banding pattern observed in this subject was not derived from proteolytic degradation of this salivary mucin in whole saliva or from genetic polymorphism. The expression of two isoforms of MG2 could in principle improve or reduce the activity of this key component of the oral host defense system.

Clinical Oral Implants Research, 2013

Purpose: This multislice tomographic study evaluated the dimensional changes after maxillary sinu... more Purpose: This multislice tomographic study evaluated the dimensional changes after maxillary sinus augmentation using autogenous bone or a mixture of hydroxyapatite and autogenous bone.

Clinical Implant Dentistry and Related Research, 2010

Background: Bone graft procedures have been used commonly in buco-maxillo-facial surgery. For thi... more Background: Bone graft procedures have been used commonly in buco-maxillo-facial surgery. For this reason, many researchers have evaluated the bone substitutes.

International journal of oral and maxillofacial surgery, 2008

The aim of this restrospective histologic study was to evaluate the bone-to-implant contact of lo... more The aim of this restrospective histologic study was to evaluate the bone-to-implant contact of loaded implants retrieved from patients with and without osteoporosis. The evaluated material consisted of 22 threaded, cylindrical, loaded dental implants retrieved from 21 patients: 7 from 7 women with postmenopausal osteoporosis (osteoporosis group) and the remaining 15 from 14 patients without history of osteoporosis or other metabolic diseases (control group). Histologic analysis revealed bone tissue in the threads of the retrieved implants, with variations in the percentage of bone-to-implant contact for the implants retrieved from both groups. The pristine bone was mostly mature bone and/or lamellar and compact, and numerous osteocytes were observed in the lacunae, although areas of woven bone could be distinguished. In some specimens, there were areas of newly formed bone exhibiting different degrees of maturation and remodeling. The mean bone-to-implant contact was 46.00+/-11.46% ...

The journal of contemporary dental practice, 2015

Some surface treatments performed on titanium can alter the composition of salivary pellicle form... more Some surface treatments performed on titanium can alter the composition of salivary pellicle formed on this abiotic surface. Such treatments modify the titanium's surface properties and can promote higher adsorption of proteins, which allow better integration of titanium to the biotic system. This study aimed to evaluate the interactions between salivary proteins and titanium disks with different surface treatments. Machined titanium disks (n = 48) were divided into four experimental groups (n = 12), according to their surface treatments: surface polishing (SP); acid etching (A); spot-blasting plus acid etching (SB-A); spot-blasting followed by acid etching and nano-functionalization (SB-A-NF). Titanium surfaces were characterized by surface roughness and scanning electron microscopy (SEM). Specimens were incubated with human saliva extracted from submandibular and sublingual glands. Total salivary protein adsorbed to titanium was quantified and samples were submitted to western...

World Journal of Orthopedics, 2015

To assess the failure and bone-to-implant contact rate of dental implants placed on osteoporotic ... more To assess the failure and bone-to-implant contact rate of dental implants placed on osteoporotic subjects.

Clinical Implant Dentistry and Related Research, 2010

Objective: The aim of this human study was to evaluate the radiation doses in the buccal cavity a... more Objective: The aim of this human study was to evaluate the radiation doses in the buccal cavity and face, during panoramic, spiral conventional tomography, and helicoidal computerized tomography exams.

BioMed Research International, 2014

Several histologic studies regarding peri-implant soft tissues and biological width around dental... more Several histologic studies regarding peri-implant soft tissues and biological width around dental implants have been done in animals. However, these findings in human peri-implant soft tissues are very scarce. Therefore, the aim of this case series was to compare the biological width around unloaded one-and two-piece implants retrieved from human jaws. Eight partially edentulous patients received 2 test implants in the posterior mandible: one-piece (solid implants that comprise implant and abutment in one piece) and two-piece (external hexagon with a healing abutment) implants. After 4 months of healing, the implants and surrounding tissue were removed for histologic analysis. The retrieved implants showed healthy peri-implant bone and exhibited early stages of maturation. Marginal bone loss, gaps, and fibrous tissue were not present around retrieved specimens. The biologic width dimension ranged between 2.55 ± 0.16 and 3.26 ± 0.15 to one-and two-piece implants, respectively ( < 0.05). This difference was influenced by the connective tissue attachment, while sulcus depth and epithelial junction presented the same dimension for both groups ( > 0.05). Within the limits of this study, it could be shown that two-piece implants resulted in the thickening of the connective tissue attachment, resulting in the increase of the biological width, when compared to one-piece implants.

Radiation Measurements, 2000

In diagnostic radiology, the radiation interaction probability in matter is a strong function of ... more In diagnostic radiology, the radiation interaction probability in matter is a strong function of the X-ray energy. The knowledge of the X-ray energy spectral distribution allows optimizing the radiographic imaging system in order to obtain high quality images with as low as reasonably achievable patient doses. In this study, transmitted X-ray spectra through dentin and enamel that are existing materials

Cadernos de Saúde Pública, 2007

Oral and Maxillofacial Surgery, 2011

Background Several studies have demonstrated the application of mini-implants in the orthodontic ... more Background Several studies have demonstrated the application of mini-implants in the orthodontic treatment as anchorage during the retraction movement of the anterior teeth. Purpose This study was designed to evaluate the mass retraction movement of the anterior upper teeth using orthodontic mini-implants as anchorage. Materials and methods Nine patients with class I malocclusion and Angle's class II, needing extractions of the upper first premolars, were enrolled in this case series. The retraction was performed using sliding mechanics and orthodontic anchorage on mini-implants. Measures were taken by initial and final cephalometric X-rays of the retraction movement to evaluate whether the mini-implants remained stationary and displacements of the incisors and the upper first premolars. Results Out of 18 mini-implants, 8 mesialized (0.45 mm, average) and 3 extruded (0.14 mm, average). The upper incisors were retracted on the average of 4.21 mm, extruded 0.33 mm, and tipped 10.3°. There were no statistical significant modifications in the placement of the posterior teeth.

Transplantation, 2008

Background. The results from reports analyzing the occurrence of gingival overgrowth (GO) induced... more Background. The results from reports analyzing the occurrence of gingival overgrowth (GO) induced by tacrolimus are controversial. In addition, the role of pharmacological and periodontal variables on the development and severity of GO have not been well-established. Therefore, the aim of the present study was to determine the effect of potential risk variables for GO in a Brazilian population comprising renal transplant recipients medicated with tacrolimus in the absence of calcium channel blockers. Materials and Methods. Demographic, pharmacological, and periodontal data, recorded from 125 subjects selected to participate in the study, was analyzed with the use of the independent sample t test, the chi-squared statistic, or Mann-Whitney test. The effects of risk variables on GO scores were subsequently examined using multivariate regression analysis and general linear model. Results. The prevalence of clinically significant GO (Ն30%) in the study population was of 7.25%. These subjects showed greater averages of plaque scores (Pϭ0.0043) as well as papillary bleeding index (Pϭ0.0026) when compared to subjects with GO Ͻ30%. Papillary bleeding index, time since transplant and azathioprine dosage were significant in the univariate and multivariate models (adjusted R 2 ϭ43.8%), whereas plaque index was significant only in the univariate model.

Journal of Radioanalytical and Nuclear Chemistry, 2011

The present study determined the organic and inorganic composition of human enamel and dentin. Th... more The present study determined the organic and inorganic composition of human enamel and dentin. The instrumental neutron activation analysis, inductivelycoupled plasma spectrometer, thermogravimetric and differential thermal analysis and X-ray diffraction analysis applied were and performed in the Nuclear Technology Development Centre (CDTN) and Elemental Analysis in the Department of Chemistry of the Federal University of Pernambuco, Brazil. The coronal dentin and enamel were separated from dentin mechanically (1) and by wear (2). The analyses were effective and led to the identification of the main elements present in enamel and dentin: Ca, Na, Cl, Zn, P, Mg, N, C, H, O. There was no contamination of samples of enamel or dentin in either separation technique; however, with separation technique 1, lower percentages of mainly Ca (7.25%) and O (15.16%) components were detected in dentin compared with technique 2.

Journal of Periodontology, 2010

Background: This prospective and controlled histologic study evaluates the impact of smoking on b... more Background: This prospective and controlled histologic study evaluates the impact of smoking on bone-to-implant contact, the bone density in the threaded area, and the bone density outside the threaded area around microimplants with anodized surface retrieved from human jaws.

Journal of Oral Science, 2007

The aims of this study were to compare nitric oxide (NO) levels in stimulated whole saliva from i... more The aims of this study were to compare nitric oxide (NO) levels in stimulated whole saliva from individuals with and without generalized chronic periodontitis (GCP), and to evaluate correlations between these levels with a clinical diagnostic parameter. According to specific criteria, 30 individuals were divided into three groups: one comprising individuals without periodontitis (GC), a second comprising individuals with moderate GCP (GM), and a third comprising individuals with advanced GCP (GA). Samples were collected and NO levels measured. NO in the GCP group (GM: 7.78 µM; GA: 15.79 µM) was higher than in the GC group (5.86 µM). NO levels in the GA group were significantly higher (P < 0.0001) than in the GC group, and could also differentiate (P < 0.0001) the moderate and advanced forms of the disease. In addition, positive correlations between NO level and the number of teeth with a probing depth of ≥ 4 mm (r = 0.54) and ≥ 7 mm (r = 0.68) were observed. In conclusion, NO levels are elevated in individuals with GPC and are correlated with a periodontal clinical parameter. These results reveal that this form of periodontal disease and its severity are related to salivary nitrite concentration, indicating that NO may serve as a potential biological marker for detection and/or monitoring of GCP. (J. Oral Sci. 49, [271][272][273][274][275][276] 2007)

Journal of Oral Implantology, 2007

The aim of this study was to evaluate the microbiota and surface of failed titanium dental implan... more The aim of this study was to evaluate the microbiota and surface of failed titanium dental implants from 4 manufacturers. Twelve mobile dental implants were retrieved from 10 smokers after 3 to 10 years of functional loading. Before implant removal, microbial samples were taken and evaluated using polymerase chain reaction. After implant removal, analyses of the failed implant surfaces were performed using scanning electron microscopy and energy-dispersive spectrometer x-ray. Periodontal pathogens such as Aggregactibacter actinomycetemcomitans, Campylobacter rectus, Eikenella corrodens, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, and Treponema denticola were detected in all implants in different proportions. Surface analysis showed varying degrees of surface roughness between the samples and the presence of proteinaceous material, appearing mainly as dark stains. Foreign carbon, oxygen, sodium, calcium, aluminum, and silicon elements were also found. Although no material-related causes of implant failure were detected, several periodontal pathogens were identified independently of the surface topography or manufacturer.

Clinical Oral Investigations, 2012

Since in a previous study we encountered a subject with an unusual split MG2 banding pattern, the... more Since in a previous study we encountered a subject with an unusual split MG2 banding pattern, the aim of this study was to investigate the molecular basis of this observation. Submandibular/sublingual secretion was collected under resting and stimulated conditions and examined on Western blots probed with anti-MG2 antibodies or on gels stained with periodic acid-Schiff reagent. Genomic DNA was isolated and the N-, tandem repeat (TR), and C-terminal regions of MUC7 were amplified by PCR since MG2 is known to display a genetic polymorphism. Although the typical appearance of MG2 on blots and gels is a single 180 kDa band, salivary secretions from the subject exhibited doublet immunoreactive bands of approximately 180 and 125 kDa. Additionally, under resting conditions the 180 kDa band was predominant whereas upon stimulation the 125 kDa band became predominant. Genomic DNA analysis showed that MUC7 in the individual with split MG2 bands was not truncated and that the MUC7 genotype in this individual was (6/6) where both alleles encoded six TRs. The MG2 split banding pattern observed in this subject was not derived from proteolytic degradation of this salivary mucin in whole saliva or from genetic polymorphism. The expression of two isoforms of MG2 could in principle improve or reduce the activity of this key component of the oral host defense system.

Clinical Oral Implants Research, 2013

Purpose: This multislice tomographic study evaluated the dimensional changes after maxillary sinu... more Purpose: This multislice tomographic study evaluated the dimensional changes after maxillary sinus augmentation using autogenous bone or a mixture of hydroxyapatite and autogenous bone.

Clinical Implant Dentistry and Related Research, 2010

Background: Bone graft procedures have been used commonly in buco-maxillo-facial surgery. For thi... more Background: Bone graft procedures have been used commonly in buco-maxillo-facial surgery. For this reason, many researchers have evaluated the bone substitutes.

International journal of oral and maxillofacial surgery, 2008

The aim of this restrospective histologic study was to evaluate the bone-to-implant contact of lo... more The aim of this restrospective histologic study was to evaluate the bone-to-implant contact of loaded implants retrieved from patients with and without osteoporosis. The evaluated material consisted of 22 threaded, cylindrical, loaded dental implants retrieved from 21 patients: 7 from 7 women with postmenopausal osteoporosis (osteoporosis group) and the remaining 15 from 14 patients without history of osteoporosis or other metabolic diseases (control group). Histologic analysis revealed bone tissue in the threads of the retrieved implants, with variations in the percentage of bone-to-implant contact for the implants retrieved from both groups. The pristine bone was mostly mature bone and/or lamellar and compact, and numerous osteocytes were observed in the lacunae, although areas of woven bone could be distinguished. In some specimens, there were areas of newly formed bone exhibiting different degrees of maturation and remodeling. The mean bone-to-implant contact was 46.00+/-11.46% ...