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1.
Odontology ; 107(2): 268, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29644480

RESUMO

In the original publication of the article, one of the author names was published incorrectly as José L. Calvo. The correct name is José L. Calvo-Guirado.

2.
Biometals ; 31(4): 679, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29725890

RESUMO

Due to an unfortunate turn of events, the surname of the fourth author appeared incorrectly in the original publication and should have read Calvo Guirado.

4.
Dent Mater J ; 37(2): 197-205, 2018 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-29415969

RESUMO

Titanium surface modification is critical for dental implant success. Our aim was to determine surfaces influence on dental pulp stem cells (DPSCs) viability and differentiation. Implants were divided into sandblasted/acid-etched (control) and sandblasted/acid-etched coated with calcium and magnesium ions (CaMg), supplied as composite (test). Proliferation was evaluated by MTT, differentiation checking osteoblastic gene expression, PGE2 secretion and matrix formation, inflammation by Interleukin 6 (IL-6) detection. MTT and IL-6 do not modify on test. A PGE2 increase on test is recorded. BMP2 is higher on test at early experimental points, Osterix and RUNX2 augment later. Alizarin-red S reveals higher matrix production on test. These results suggest that test surface is more osteoinductive, representing a start point for in vivo studies aiming at the construction of more biocompatible dental implants, whose integration and clinical performance are improved and some undesired effects, such as implant stability loss and further surgical procedures, are reduced.


Assuntos
Polpa Dentária/citologia , Osteoblastos/citologia , Células-Tronco/citologia , Titânio/química , Condicionamento Ácido do Dente , Cálcio/química , Técnicas de Cultura de Células , Diferenciação Celular , Proliferação de Células , Sobrevivência Celular , Células Cultivadas , Polpa Dentária/metabolismo , Dinoprostona/metabolismo , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Humanos , Técnicas In Vitro , Interleucina-6/metabolismo , Magnésio/química , Teste de Materiais , Microscopia Eletrônica de Varredura , Reação em Cadeia da Polimerase , Células-Tronco/metabolismo , Propriedades de Superfície
5.
Materials (Basel) ; 10(5)2017 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-28772900

RESUMO

Some studies have demonstrated that in vivo degradation processes are influenced by the material's physico-chemical properties. The present study compares two hydroxyapatites manufactured on an industrial scale, deproteinized at low and high temperatures, and how physico-chemical properties can influence the mineral degradation process of material performance in bone biopsies retrieved six months after maxillary sinus augmentation. Residual biomaterial particles were examined by field scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) to determine the composition and degree of degradation of the bone graft substitute material. According to the EDX analysis, the Ca/P ratio significantly lowered in the residual biomaterial (1.08 ± 0.32) compared to the initial composition (2.22 ± 0.08) for the low-temperature sintered group, which also presented high porosity, low crystallinity, low density, a large surface area, poor stability, and a high resorption rate compared to the high-temperature sintered material. This demonstrates that variations in the physico-chemical properties of bone substitute material clearly influence the degradation process. Further studies are needed to determine whether the resorption of deproteinized bone particles proceeds slowly enough to allow sufficient time for bone maturation to occur.

6.
Materials (Basel) ; 10(6)2017 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-28773005

RESUMO

The aim of the present study was to monitor implant stability after sinus floor elevation with two biomaterials during the first six months of healing by resonance frequency analysis (RFA), and how physico-chemical properties affect the implant stability quotient (ISQ) at the placement and healing sites. Bilateral maxillary sinus augmentation was performed in 10 patients in a split-mouth design using a bobine HA (BBM) as a control and porcine HA (PBM). Six months after sinus lifting, 60 implants were placed in the posterior maxilla. The ISQ was recorded on the day of surgery from RFA at T1 (baseline), T2 (three months), and T3 (six months). Statistically significant differences were found in the ISQ values during the evaluation period. The ISQ (baseline) was 63.8 ± 2.97 for BBM and 62.6 ± 2.11 for PBM. The ISQ (T2) was ~73.5 ± 4.21 and 67 ± 4.99, respectively. The ISQ (T3) was ~74.65 ± 2.93 and 72.9 ± 2.63, respectively. All of the used HAs provide osseointegration and statistical increases in the ISQ at baseline, T2 and T3 (follow-up), respectively. The BBM, sintered at high temperature with high crystallinity and low porosity, presented higher stability, which demonstrates that variations in the physico-chemical properties of a bone substitute material clearly influence implant stability.

7.
Materials (Basel) ; 10(7)2017 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-28773119

RESUMO

This study aimed to investigate the processing parameters and biocompatibility of a novel biphasic dicalcium silicate (C2S) cement. Biphasic α´L + ß-C2Sss was synthesized by solid-state processing, and was used as a raw material to prepare the cement. In vitro bioactivity and biocompatibility studies were assessed by soaking the cement samples in simulated body fluid (SBF) and human adipose stem cell cultures. Two critical-sized defects of 6 mm Ø were created in 15 NZ tibias. A porous cement made of the high temperature forms of C2S, with a low phosphorous substitution level, was produced. An apatite-like layer covered the cement's surface after soaking in SBF. The cell attachment test showed that α´L + ß-C2Sss supported cells sticking and spreading after 24 h of culture. The cement paste (55.86 ± 0.23) obtained higher bone-to-implant contact (BIC) percentage values (better quality, closer contact) in the histomorphometric analysis, and defect closure was significant compared to the control group (plastic). The residual material volume of the porous cement was 35.42 ± 2.08% of the initial value. The highest BIC and bone formation percentages were obtained on day 60. These results suggest that the cement paste is advantageous for initial bone regeneration.

8.
Clin Oral Implants Res ; 28(3): 355-361, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26925570

RESUMO

OBJECTIVES: The aim of this study was to perform a histomorphometric and biomechanical comparison of three implants with different designs of the apical area to promote a better bone initial stability and its correlation with the osseointegration. MATERIAL AND METHODS: Fifty-four tapered implants with same length, diameter and surface properties but with three different apical configurations (Group I: MK4: Group II: C1 and Group III: MK7) were inserted in the tibia of rabbits. Implant stability and bone formation were evaluated by resonance frequency analysis measured at 0, 6, 8 and 12 weeks and by histomorphometric analysis performed at 6, 8 and 12 weeks. RESULTS: Statistical test to compare the stability through the implant stability quotient in the four times showed few differences between the groups and time periods proposed, with significance set at P < 0.05. In the bone-implant contact, by comparing the groups in the three times proposed, it was possible concluded that there is a similar behavior among the three implant design (P < 0.05). CONCLUSION: With the limitations of this animal study, it can be concluded that the design of the apical area influences the implant stability and the bone-to-implant contact.


Assuntos
Implantes Dentários , Planejamento de Prótese Dentária , Osseointegração , Animais , Fenômenos Biomecânicos , Implantes Experimentais , Coelhos , Propriedades de Superfície , Tíbia
9.
Clin Oral Implants Res ; 27(11): 1368-1375, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26775798

RESUMO

OBJECTIVE: The aims of the present work were to study a new porous Nurse's A ceramic (Si-Ca-P-based material) bone substitute and examine its mechanical properties in vitro and the biocompatibility, osteoconductivity and resorption process in vivo. MATERIALS AND METHOD: Porous ceramic scaffolds were prepared by solid-state reaction and implanted in critical-sized defect created in 15 NZ rabbits. Strength values were determined by the diametrical compression of disk test. Weibull analyses were performed following the European Standard for technical ceramics EN-843-5: 1996, considering 90% of confidence intervals. Results were correlated with scanning microscope observations of fracture surfaces. Implanted scaffolds were characterized by histological and histomorphometric point of view. RESULTS: The parameters of the Weibull distribution of strength, determined by diametrical compression of disks, were modulus m = 13, and characteristic strength σ0  = 0.60 MPa (90% confidence limit: m = 7.2-17.6, σ0  = 0.570-0.578). Porous calcium silicophosphate scaffolds showed significantly more bone formation in the pores and in the periphery of the implant than the control group. Histomorphometric analysis revealed that the ceramic scaffold (62.23 ± 0.34*) produced higher values of bone-to-implant contact (BIC) percentages (higher quality, closer contact); moreover, defect closure was significative in relation with control group. CONCLUSIONS: The porous calcium silicophosphate ceramic is biocompatible, partially resorbable and osteoinductive material. This rabbit study provides radiological and histological evidences confirming the suitablity of this new material for bone tissue regeneration on critical defects.


Assuntos
Materiais Biocompatíveis/farmacologia , Substitutos Ósseos/farmacologia , Compostos de Cálcio/farmacologia , Cerâmica/farmacologia , Osteogênese , Tíbia/cirurgia , Animais , Materiais Biocompatíveis/síntese química , Regeneração Óssea , Substitutos Ósseos/síntese química , Cerâmica/síntese química , Masculino , Teste de Materiais , Microscopia Eletrônica de Varredura , Osteogênese/efeitos dos fármacos , Porosidade , Coelhos , Silicatos , Alicerces Teciduais
10.
Clin Oral Implants Res ; 27(7): 896-903, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26419393

RESUMO

OBJECTIVE: The aim of this study was to evaluate the effect of topical application of vitamin D over implant surface, placed immediately to the extraction, throughout histological and histomorphometric analysis of peri-implant tissue. MATERIAL AND METHODS: Six American foxhound dogs were used in the study. Mandibular premolar distal roots were extracted. Twenty-four immediate conical C1 implants (MIS, Barlev, Israel) were randomly assigned to the distal site on each site of the mandible in three groups: (Group CI) 12 titanium implants alone; (Test Group DI) 12 titanium implants supplemented with vitamin D. Prior to implanting, test implants (DI) were submerged in vitamin D 10% solution. No treatment was applied at control implants (CI). After 12 weeks, animals were sacrificed. Block sections were obtained and processed for mineralized ground sectioning. Bone-to-implant contact (Total BIC and BIC%), new bone formation (NBF), interthread bone (ITB), and histological linear measurements (HLM) were analyzed. RESULTS: At 12 weeks, all implants were clinically stable and histologically osseointegrated. BIC evaluation showed Total BIC mean and SD values for DI (48.96 ± 2.14), CI (44.56 ± 1.75) (P < 0.05), BIC% DI (43.59 ± 0.98), and CI (42.67 ± 9.26) (P > 0.05). For interthread bone formation, values were as follows: DI (15.21 ± 3.87), CI (14.79 ± 1.45) (P > 0.05), no statistically differences. Regarding peri-implant new bone formation, no statistically differences could be found between the two groups DI (31.87 ± 1.23), CI (27.18 ± 2.38) (P > 0.05). For linear measurements, test group (DI) showed statistically significant less buccal crestal bone loss (CBL) DI (0.37 ± 0.12)*, CI (1.26 ± 0.8) (P < 0.05), and vitamin D implants showed less lingual junctional epithelium DI (1.58 ± 0.43)*, CI (2.18 ± 0.48) (P < 0.05). No differences were observed in the buccal mucosa. CONCLUSION: With the limitation of animal studies, topical application of vitamin D on dental implants could reduce crestal bone loss and increase 10% more bone-to-implant contact at 12-week follow-up period.


Assuntos
Interface Osso-Implante , Implantes Dentários , Osteogênese , Vitamina D/farmacologia , Perda do Osso Alveolar/prevenção & controle , Animais , Cães , Implantes Experimentais , Osseointegração , Projetos Piloto
11.
Clin Oral Implants Res ; 27(11): 1331-1338, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26666991

RESUMO

OBJECTIVE: The aim of this study was the synthesis and analysis of the tissue reaction to three different Hydroxyapatite (HA)-based bone substitute materials differing only in granule size, porosity, and crystallinity through an animal experimental model at 60 days. MATERIALS AND METHODS: Three different HA-based biomaterials were synthesized and characterized by X-ray diffraction, SEM, and EDS analysis, the resultant product was ground in three particle sizes: Group I (2000-4000 µm), Group II (1000-2000 µm), and Group III (600-1000 µm). Critical size defects were created in both tibias of 15 rabbits. Four defects per rabbit for a total of 60 defects were grafted with the synthesized materials as follows: Group I (15 defects), Group II (15 defects), Group III (15 defects), and empty (15 defects control). After animals sacrifice at 60 days samples were obtained and processed for SEM and EDS evaluation of Ca/P ratios, elemental mapping was performed to determine the chemical degradation process and changes to medullary composition in all the four study groups. RESULTS: The tendency for the density was to increase with the increasing annealing temperature; in this way it was possible to observe that the sample that shows highest crystallinity and crystal size corresponding to that of group I. The SEM morphological examination showed that group III implant showed numerous resorption regions, group II implant presented an average resorption rate of all the implants. The group I displayed smoother surface features, in comparison with the other two implants. CONCLUSION: The data from this study show that changing the size, porosity, and crystallinity of one HA-based bone substitute material can influence the integration of the biomaterials within the implantation site and the new bone formation.


Assuntos
Materiais Biocompatíveis/química , Substitutos Ósseos/química , Durapatita/química , Osseointegração , Animais , Materiais Biocompatíveis/síntese química , Substitutos Ósseos/síntese química , Cristalização , Durapatita/síntese química , Masculino , Teste de Materiais , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Porosidade , Coelhos , Propriedades de Superfície , Tíbia/cirurgia , Difração de Raios X
12.
Clin Oral Implants Res ; 27(1): 90-6, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25358335

RESUMO

OBJECTIVES: The aim of this animal study was to compare the effects of narrow, concave-straight and wide anatomic healing abutments on changes to soft tissues and crestal bone levels around implants immediately placed into extraction sockets in foxhound dogs. MATERIALS AND METHODS: Forty-eight titanium implants (Bredent Medical GMBH, Germany) of the same dimensions were placed in six foxhound dogs. They were divided into two groups (n = 24): test (implants with anatomic abutment) and control (implants with concave-straight abutment). The implants were inserted randomly in the post extraction sockets of P2 , P3 , P4, and M1 bilaterally in six dogs. After eight and twelve weeks, the animals were sacrificed and samples extracted containing the implants and the surrounding soft and hard tissues. Soft tissue and crestal bone loss (CBL) were evaluated by histology and histomorphometry. RESULTS: All implants were clinically and histologically osseointegrated. Healing patterns were examined microscopically at eight and twelve weeks. After eight and twelve weeks, for hard tissues, the distance from the implant shoulder to the first bone-to-implant contact (IS-C) was higher for control group in the lingual aspect with statistical significance (P < 0.05). For soft tissues (STL), the distance from the top of the peri-implant mucosa to the apical portion of the junction epithelium (PM-Je) was significantly less on the lingual aspect in the test group (with wider abutment) at eight and twelve weeks (P < 0.05). The distance from the top of the apical portion of the junction epithelium to the first bone-to-implant contact (Je-C) was significantly higher in the test group (wider abutment) in the lingual aspect at eight and twelve weeks (P < 0.05). There was no connective tissue contact with any abutment surface. CONCLUSIONS: Within the limitations of this animal study, anatomic healing abutments protect soft and hard tissues and reduce crestal bone resorption compared with concave-straight healing abutments.


Assuntos
Implantes Dentários , Planejamento de Prótese Dentária , Carga Imediata em Implante Dentário , Alvéolo Dental/cirurgia , Cicatrização/fisiologia , Animais , Dente Suporte , Cães , Gengiva/fisiologia , Gengiva/cirurgia , Osseointegração/fisiologia , Projetos Piloto , Propriedades de Superfície , Titânio , Extração Dentária
13.
Clin Oral Implants Res ; 27(11): e105-e115, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25727443

RESUMO

OBJECTIVES: The aim of this randomized clinical trial was to analyse and compare the volumetric changes after ridge preservation procedures using two different biomaterials and to evaluate associations between outcome variables and pristine three-dimensional aspects of the ridges. MATERIALS AND METHODS: Twenty-eight patients subjected to single-tooth alveolar ridge preservation were enrolled in the present multicentre, single-blind, prospective and randomized clinical trial. Fourteen sites were randomly allocated to each experimental group. The experimental sites were grafted with pre-hydrated collagenated cortico-cancellous porcine bone (coll group) or with a cortical porcine bone (cort group) and a collagen membrane; a secondary soft tissue healing was obtained for all experimental sites. Plaster casts were scanned (preoperative, at 1 and 3 months postoperative). Analysis of volumes and areas was performed, and all measured variables were statistically compared. RESULTS: Intragroup analyses at 3 months revealed that when examining changes related to three-dimensional features of remodelling patterns (volume, surfaces, height and shape), the two biomaterials showed similar behaviours with a minor loss in volume and ridge surface. Intergroup analysis at 3-month survey revealed that volume resorption of the coll group (244 mm3 ) was significantly lower (P = 0.0140) than that of the cort group (349 mm3 ). The reduction for basal surface appeared significantly different between the two groups at 1-month survey only (P = 0.0137), while the final basal surface reduction was 4.9 and 12.2 mm2 for coll and cort group, respectively. The superior surface reduction was 40.8 mm2 for coll and 50.7 mm2 for cort group, with no significant difference between the two groups. CONCLUSION: At the 3rd month analysis, coll group showed a significantly lower reduction of ridge volume and a significantly smaller shrinkage of the basal area when compared to the cort group; moreover, the coll group experienced a smaller superior surface shrinkage when compared to the cort group, even though no significance was evaluated.


Assuntos
Aumento do Rebordo Alveolar/métodos , Remodelação Óssea/fisiologia , Transplante Ósseo/métodos , Alvéolo Dental/cirurgia , Adulto , Idoso , Animais , Colágeno , Tomografia Computadorizada de Feixe Cônico , Feminino , Xenoenxertos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Método Simples-Cego , Suínos , Alvéolo Dental/diagnóstico por imagem
14.
Clin Oral Implants Res ; 26(7): 761-7, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24422555

RESUMO

OBJECTIVE: To evaluate marginal bone loss over 3 years around immediate microthreaded implants placed in the maxillary anterior/esthetic zone and immediately restored with single crowns. MATERIAL AND METHODS: Seventy-one implants (with microthreads up to the platform--rough surface body and neck, internal connection and platform switching) were placed in fresh extraction sockets in the maxillary arches of 30 men and 23 women (mean age 37.85 ± 7.09 years, range 27-60). All subjects had at least 3 mm of soft tissue to allow the establishment of adequate biologic width and to reduce bone resorption. Each patient received a provisional restoration immediately after implant placement with slight occlusal contact. Mesial and distal bone height was evaluated using digital radiography on the day following implant placement (baseline) and after 1, 2, and 3 years. Primary stability was measured with resonance frequency analysis. RESULTS: No implants failed, resulting in a cumulative survival rate of 100% after 3 years. Marginal bone loss from implant collar to bone crest measured at baseline (peri-implant bone defect at the fresh extraction socket) and after 3 years was 0.86 mm ± 0.29 mm. Mesial and distal site crestal bone loss ranged from 3.42 mm ± 1.2 mm at baseline to 3.51 mm ± 1.5 mm after 3 years (P = 0.063) and from 3.38 mm ± 0.9 mm at baseline to 3.49 mm ± 0.9 mm after 3 years, respectively (P = 0.086). CONCLUSIONS: This prospective study found minimal marginal bone loss and a 100% implant survival rate over the 3-year follow-up for microthreaded immediate implants subjected to immediate non-occlusal loading.


Assuntos
Perda do Osso Alveolar/etiologia , Implantes Dentários para Um Único Dente , Carga Imediata em Implante Dentário/métodos , Maxila/cirurgia , Adulto , Perda do Osso Alveolar/diagnóstico por imagem , Coroas , Planejamento de Prótese Dentária , Feminino , Humanos , Masculino , Maxila/diagnóstico por imagem , Estudos Prospectivos , Propriedades de Superfície
15.
Clin Oral Implants Res ; 25(3): 344-351, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23346955

RESUMO

OBJECTIVES: The aim of the present study was to evaluate bone-to-implant contact (BIC) and bone remodeling dynamics after immediate implant placement at different levels in relation to the crestal bone. MATERIALS AND METHODS: The mandibular second, third, and fourth premolars of six Foxhound dogs were extracted bilaterally. Randomly, three implants were immediately placed in the hemi-arches of each dog, crestally or 2 mm subcrestally. Three dogs were allowed an 8-week submerged healing period, and the other three at 12-week submerged healing period. The animals were sacrificed at 12 weeks and samples were obtained. Biopsies were processed for ground sectioning. Histomorphometric analysis was carried out to compare BIC, bone neoformation, and bone remodeling. RESULTS: All implants osseointegrated clinically and histologically. Healing patterns examined microscopically at eight and twelve weeks for both groups (crestal and subcrestal) yielded similar qualitative bone findings. The Total BIC mean value for the crestal group 44.52% at 8 weeks and 39.50% at 12 weeks, and for the subcrestal group was 47.33% at 8 weeks and 53.85% at 12 weeks%. There was less bone resorption in the subcrestal group (test) than in crestal group (control). CONCLUSIONS: Within the limitations of this study, our findings suggest that apical positioning of the top of the implant does not jeopardize bone crest and peri-implant tissue remodeling. However, less resorption of the lingual crest may be expected when implants are placed 2 mm subcrestally. Moreover, higher BIC values were found in implants placed subcrestally.


Assuntos
Processo Alveolar/cirurgia , Carga Imediata em Implante Dentário , Processo Alveolar/patologia , Animais , Dente Pré-Molar/cirurgia , Biópsia , Remodelação Óssea/fisiologia , Reabsorção Óssea/patologia , Cães , Implantes Experimentais , Osseointegração/fisiologia , Projetos Piloto , Distribuição Aleatória , Extração Dentária , Cicatrização/fisiologia
16.
Clin Oral Implants Res ; 25(7): 826-30, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23551427

RESUMO

OBJECTIVE: The aim of this study was to assess the performance of zirconia implants under immediate loading compared with delayed loading in dogs over 30-90 days. MATERIALS AND METHODS: Tooth extractions were made for the subsequent placement of dental implants at premolars P2, P3, P4 and molars M1 bilaterally in the dog mandible. Forty eight zirconia implants, 4 mm in diameter and 10 mm in length, were inserted, whose neck and body surfaces had been treated with femtosecond laser texturing; 24 implants were loaded immediately and 24 remained unloaded during the osseointegration period. Final radiographs were taken recording stability values before sacrifice at 30 or 90 days when sample removal for histological and histomorphometric analysis was performed. Bone-to-implant contact, crestal bone loss and implant stability were evaluated at these two study times. RESULTS: Bone-to-implant contact values after 30 days were 38.9% for immediately loaded implants and 32% for non-loaded implants. After 90 days, values increased to 65% for immediately loaded and 57.6% for non-loaded implants. After 30 days, there was more crestal bone lost in the non-loaded group (0.58 ± 0.28 mm) compared with the immediately loaded group (0.5 ± 0.3 mm). After 90 days, there was improved stability in both groups, but was lower in the immediately loaded group (0.5 ± 0.23 mm) compared with the non-loaded group (0.56 ± 0.28 mm). Initial implant stability values were -3.5 PTV at the moment of implant placement. Stability values after the first 30 days were -4 for immediately loaded implants and -3 for non-loaded. At 90 days, non-loaded implants showed -4.9, whereas immediately loaded showed -7.1. CONCLUSIONS: For the different parameters studied, zirconia implants treated with femtosecond laser and subjected to immediate loading showed better results compared with non-loaded implants in terms of BIC, crestal bone loss and implant stability.


Assuntos
Perda do Osso Alveolar/patologia , Implantação Dentária Endóssea/métodos , Implantes Dentários , Perda do Osso Alveolar/diagnóstico por imagem , Animais , Reabsorção Óssea/patologia , Planejamento de Prótese Dentária , Cães , Carga Imediata em Implante Dentário/métodos , Lasers , Masculino , Mandíbula/cirurgia , Modelos Animais , Osseointegração/fisiologia , Radiografia , Propriedades de Superfície , Extração Dentária , Zircônio
17.
Clin Oral Implants Res ; 25(11): 1228-1238, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24025159

RESUMO

OBJECTIVES: The aim of this study was to investigate, by means of radiological and histomorphometric analysis, the effect of resorbable collagen membranes on critical size defects (CSD) in rabbit tibiae filled with biphasic calcium phosphate. MATERIALS AND METHODS: Three CSD of 6 mm diameter were created in both tibiae of 20 New Zealand rabbits and divided into three groups according to the filling material: Group A (Ossceram), Group B (Ossceram plus Alveoprotect membrane), and Group C (unfilled control group). Five animals from each group were sacrificed after 15, 30, 45, and 60 days. Anteroposterior and lateral radiographs were taken. Samples were processed for observation under light microscopy. RESULTS: At the end of treatment, radiological analysis found that cortical defect closure was greater in Group B than Group A, and radiopacity was clearly lower and more heterogeneous in the Group A cortical defects than in Group B. There was no cortical defect closure in Group C. Histomorphometric evaluation showed significant differences in newly formed bone and cortical closure in Group B compared with Groups A and C, with the presence of higher density newly formed bone in cortical and medullar zones. There was no cortical defect closure or medullar bone formation in Group C. CONCLUSIONS: Biphasic calcium phosphate functioned well as a scaffolding material allowing mineralized tissue formation. Furthermore, the addiction of absorbable collagen membranes enhanced bone gain compared with non-membrane-treated sites.


Assuntos
Implantes Absorvíveis , Doenças Ósseas/cirurgia , Substitutos Ósseos/uso terapêutico , Fosfatos de Cálcio/uso terapêutico , Colágeno , Membranas Artificiais , Tíbia/cirurgia , Animais , Densidade Óssea/fisiologia , Doenças Ósseas/diagnóstico por imagem , Doenças Ósseas/patologia , Regeneração Óssea/fisiologia , Regeneração Tecidual Guiada/métodos , Osteogênese/fisiologia , Coelhos , Intensificação de Imagem Radiográfica/métodos , Tíbia/diagnóstico por imagem , Tíbia/patologia , Fatores de Tempo
18.
Clin Oral Implants Res ; 25(2): e54-63, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23057529

RESUMO

PURPOSE: The aim of this study was to evaluate bone remodelling and soft tissue reactions around immediate nonocclusal loaded implants with different collar configuration in beagle dogs. MATERIAL AND METHODS: The mandibular bilateral second, third and fourth premolars of six beagle dogs were extracted. After 3 months of healing, four implants were placed in the mandibles of each dog. Randomly, two implants with a 1.5 mm polished surface collar (TSA, control group) and two implants with a 0.7 mm polished surface collar and 2.5 mm microthreaded area (TSAA, test group) were inserted. Both groups were treated with a minimal mucoperiosteal flap elevation approach. Impressions were taken and two single screw-retained restorations were inserted in each hemi-mandible 2 days after the implant placement. The animals were sacrificed at 1, 2 and 3 months (two specimens each), and biopsies were obtained. Samples were processed for ground sectioning. Histomorphometric analysis was carried out to compare buccal and lingual bone height loss and soft tissue behaviour between the two groups. RESULTS: Crestal bone resorption was significantly higher in the control group (P > 0.05). The establishment of the biological width showed similar outcomes for both groups. Only the distance from the top of the peri-implant mucosa to the apical portion of the barrier epithelium at lingual aspect was significantly more pronounced in the control group (P > 0.05). CONCLUSIONS: The alterations that occurred in the peri-implant tissues were related to the adaptation that occurred after the loading conditions in both groups. The microthread design might have an effect in maintaining the marginal bone loss against loading.


Assuntos
Adaptação Fisiológica/fisiologia , Perda do Osso Alveolar/patologia , Implantes Dentários , Carga Imediata em Implante Dentário , Animais , Dente Pré-Molar/cirurgia , Remodelação Óssea , Reabsorção Óssea/patologia , Planejamento de Prótese Dentária , Cães , Implantes Experimentais , Mandíbula/cirurgia , Osseointegração/fisiologia , Retalhos Cirúrgicos , Extração Dentária , Cicatrização/fisiologia
19.
Int J Mol Cell Med ; 3(4): 225-36, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25635249

RESUMO

Titanium (Ti) is one of the most widely used biomaterials for manufacturing dental implants. The implant surface properties strongly influence osseointegration. The aim of the present study was to in vitro investigate the characteristics of Ti dental implants in terms of mutagenicity, hemocompatibility, biocompatibility, osteoinductivity and biological safety. The Ames test was used to test the mutagenicity of the Ti dental implants, and the hemolysis assay for evaluating their hemocompatibility. Human adipose - derived stem cells (ADSCs) were then seeded onto these implants in order to evaluate their cytotoxicity. Gene expression analyzing with real-time PCR was carried out to investigate the osteoinductivity of the biomaterials. Finally, the genetic stability of the cells cultured onto dental implants was determined by karyotyping. Our results demonstrated that Ti dental implants are not mutagenic, do not cause hemolysis, and are biocompatible. The MTT assay revealed that ADSCs, seeded on Ti dental implants, proliferate up to 30 days in culture. Moreover, ADSCs loaded on Ti dental implants show a substantial expression of some osteoblast specific markers, such as COL1A1, OPN, ALPL, and RUNX2, as well as chromosomal stability after 30 days of culture in a medium without osteogenic factors. In conclusion, the grit-blasted and acid-etched treatment seems to favor the adhesion and proliferation of ADSCs and improve the osteoinductivity of Ti dental implant surfaces.

20.
Microsc Microanal ; 19(5): 1350-7, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23823628

RESUMO

This article reports the structure and morphology of the in vivo interface between implants composed of either a tricalcium phosphate (αTCP) or αTCP doped with 3.0 wt% dicalcium silicate (αTCP(ss)) ceramic, and natural bone of rabbit tibias. Both interfaces developed a new bone layer in direct contact with the implants after 4 and 8 weeks of implantation. The specimens were examined using analytical scanning and transmission electron microscopy, up to the lattice plane resolution level. Degradation processes of the implants developed at the interfaces encouraged osseous tissue ingrowth into the periphery of the material, changing the microstructure of the implants. The ionic exchange initiated at the implant interface with the environment was essential in the integration process of the implant, through a dissolution­precipitation­transformation mechanism. The interfaces developed normal biological and chemical activities and remained reactive over the 8-week period. Organized collagen fibrils were found at the αTCP(ss)/bone interface after 4 weeks, whereas a collagen-free layer was present around the Si-free αTCP implants. These findings suggest that the incorporation of silicate ions into αTCP ceramic promotes processes of the bone remodeling at the bone/αTCP(ss) interface, hence the solubility rate of the aTCP(ss) material decreased.


Assuntos
Materiais Biocompatíveis/metabolismo , Fosfatos de Cálcio/metabolismo , Cerâmica/metabolismo , Animais , Biotransformação , Colágeno/metabolismo , Implantes Experimentais , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Coelhos , Silicatos/metabolismo , Tíbia/metabolismo
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