UNIVERSIDADE FEDERAL FLUMINENSE FACULDADE DE ODONTOLOGIA
AVALIAÇÃO
DAS
MODIFICAÇÕES
DA
SUPERFÍCIE
DOS
IMPLANTES APÓS INSERÇÃO - UM ESTUDO LABORATORIAL
Niterói 2016
UNIVERSIDADE FEDERAL FLUMINENSE FACULDADE DE ODONTOLOGIA
AVALIAÇÃO
DAS
MODIFICAÇÕES
DA
SUPERFÍCIE
DOS
IMPLANTES APÓS INSERÇÃO - UM ESTUDO LABORATORIAL
DANIEL DE MATTOS SALIM
Dissertação apresentada à Faculdade de Odontologia da Universidade Federal Fluminense, como parte dos requisitos para obtenção do título de Mestre, pelo Programa de Pós-Graduação em Odontologia.
Área de Concentração: Clínica Odontológica
Orientador: Prof. Dr. Cresus Vinicius Depes de Gouvêa
Niterói 2016
S165 Salim, Daniel de Mattos
Avaliação das modificações da superfície dos implantes após inserção: um estudo laboratorial / Daniel de Mattos Salim; orientador: Prof. Dr. Cresus Vinícius Depes da Gouvêa - Niterói: [s.n.], 2016.
35 f.: il.
Inclui gráficos e tabelas
Dissertação (Mestrado em Clínica odontológica) – Universidade Federal Fluminense, 2016.
Bibliografia: f. 30-34
1.Implante dentário 2.Rugosidade superficial 3.Caracterização da superfície I.Gouvêa, Cresus Vinícius Depes de [orien.] II.Título
BANCA EXAMINADORA
Prof(a). Dr(a). Cresus Vinicius Depes de Gouvêa
Instituição: Faculdade de Odontologia da Universidade Federal Fluminense Decisão: __________________________
Assinatura: ________________________________________________________
Prof(a). Dr(a). Marco Antônio Gallito
Instituição: Faculdade de Odontologia da Universidade Federal Fluminense Decisão: __________________________
Assinatura: ________________________________________________________
Prof(a). Dr(a). Mônica Zacharias Jorge
Instituição: Faculdade de Odontologia da Universidade Federal do Rio de Janeiro Decisão: __________________________
DEDICATÓRIA
A Deus, aos meus pais, amigos, e aos meus professores, pelo apoio, confiança e motivação.
AGRADECIMENTOS
A Deus, por fazer parte da minha vida;
Aos meus pais, por todos os incentivos; e pelo afeto que sempre me dedicaram; A esta Universidade, seu corpo docente e administrativo, pelo mérito e ética aqui
presente;
Ao meu Orientador prof. Cresus Vinicius Depes de Gouvêa, pela oportunidade e por todo suporte;
Ao meu Co-orientador prof. Waldimir Carvalho, por sua atenção, disponibilidade e
por todo seu apoio na elaboração deste trabalho.
A todos os amigos que fizeram parte da minha formação, principalmente, a amiga Marina Teixeira.
E aos técnicos do Laboratório de Biotecnologia Aplicada (LABA), Marcos e Welington.
Muito Obrigado.
.
“Quanto mais aumenta nosso conhecimento, mais evidente fica nossa ignorância.” John F. Kennedy
Salim DM; Gouvêa CVD. AVALIAÇÃO DAS MODIFICAÇÕES DA SUPERFÍCIE DOS IMPLANTES APÓS INSERÇÃO - UM ESTUDO LABORATORIAL. [dissertação]. Niterói: Universidade Federal Fluminense, Faculdade de Odontologia; 2016.
Objetivo: Avaliar a superfície dos implantes após a instalação em poliuretano (osso artificial) e possíveis implicações dos detritos de partículas destas superfícies. Metodologia: Quinze implantes comerciais, de superfícies, anodizada (5), duplo ataque ácido (5) e ataque ácido (5) foram instalados em blocos de osso artificial de poliuretano de densidade correspondente ao osso D1, D2 utilizando brocas próprias para inserção de implantes. Uma perfuração foi feita na linha da interface entre uma metade e outra do osso artificial com torque máximo de 45Ncm. As deformações macro e microscópicas dos implantes foram avaliadas antes e depois do ato da inserção, em Microscópio Eletrônico de Varredura (MEV). Os blocos de osso foram separados em duas metades pós-inserção e avaliados através de MEV e Espectroscopia de Energia Dispersiva (EDS). Resultados: O MEV mostrou danos na superfície dos implantes pós-inserção. Implantes anodizados demonstraram danos amplos; onde parte da camada de óxido foi removida nas cristas das roscas, expondo o material subjacente. Nos blocos de poliuretano onde os implantes anodizados foram instalados partículas de titânio de diferentes tamanhos foram encontradas. Conclusão: O presente estudo demonstrou danos na superfície pós-inserção de implantes anodizados em blocos de poliuretano, associados com partículas de titânio na interface. Implantes com tratamento de ataque ácido e duplo ataque ácido não apresentaram mundaças significativas
Palavras-chave: Implantes Dentários, osteólise, caracterização de superfície, rugosidade superficial.
ABSTRACT
Salim DM; Gouvêa CVD. EVALUATION OF IMPLANT SURFACE MODIFICATIONS POST-INSERTION – A LABORATORY STUDY. [thesis, dissertation]. Niterói: Federal Fluminense University, School of Dentistry; 2016.
Objective: To evaluate the effects on the surface of the implants after the artificial bone installation and possible implications of particles of debris from these surfaces. Methods: Fifteen commercial implants of surfaces, anodized (5), double acid-etched (5) and acid-etched (5) have been installed in polyurethane artificial bone block corresponding bone density D1, D2 using proper drills for inserting implants. A perforation was made in the line interface between a half and another of artificial bone with maximum torque 45Ncm. Macro and microscopic implants deformations were evaluated before and after the act of insertion in Scanning Electron Microscope (SEM). Bone blocks were separated into two halves post insertion and were evaluated by SEM and Energy Dispersive Spectroscopy (EDS). Results: SEM showed damage to the surface after insertion. Anodised implants demonstrated large damage, in which part of the oxide layer was removed from the crests of the threads, exposing the underlying material. In polyurethane blocks in which the anodized implants were installed titanium particles in different sizes were found. Conclusion: This study showed damage to the surface post insertion of anodized implants, and titanium particles were found in polyurethane bone blocks.
1 - INTRODUÇÃO
A osseointegração é o contato físico entre o corpo do implante e osso vivo circunjacente. A superfície dos implantes modernos tem sido tratada com a finalidade de melhorar a osseointegração. (ALBREKTSSON et al, 1981).
O tratamento de superfície confere a um implante um grau de rugosidade melhor do que um implante maquinado. A estabilidade primária do implante é um pré-requisito para a sobrevivência do implante, impedindo, assim, a formação de uma camada de tecido conjuntivo entre implante e osso, garantindo consequentemente a cicatrização óssea (BRANEMARK et al, 1977).
Os tratamentos de superfícies podem ser divididos em grupos. O primeiro é formado por implantes recobertos com hidroxiapatita, o segundo grupo por jateamento com partículas abrasivas, ataque com ácidos ou deposição de partículas de óxido de titânio, um terceiro grupo com tratamentos termoquímicos para ativar a superfície do titânio e aumentar a espessura da camada de óxido, o quarto grupo é usado na condição de usinado. (ELIAS et al, 2004).
As características dos biomateriais, tais como, topografia da superfície, cargas de superfície, componentes, estados químicos e molhabilidade têm influência nas interações sobre a matriz óssea, osteoblastos e os biomateriais. (FENG et al,2003; FENG et al, 2004).
Os resultados de vários estudos sugerem que uma série de fatores influencia na estabilidade primária de um implante dental, tais como, a quantidade e a densidade do osso no lugar onde o implante foi colocado (SEVIMAY et al, 2005), técnica cirúrgica, isto é, a correlação entre o tamanho da broca e o tamanho do implante (SENNERBY&ROOS, 1998) e a morfologia microscópica e macroscópica do implante utilizado (HANSSON 1999, O’SULLIVAN et al, 2004).
O sucesso da osseointegração depende do material empregado, do processo de fabricação, condições de usinagem, morfologia do implante, tipo do
osso, técnica cirúrgica, elaboração da prótese e das condições de carregamento impostas durante a mastigação. (LINDHE 1999; MISCH 2008).
Técnicas de avaliação de superfícies tais como Espectroscopia de Energia Dispersiva (EDS) e Microscopia Eletrônica de Varredura (MEV) tornam possível identificar diferenças entre as superfícies dos implantes com ou sem tratamento de superfície, essas técnicas podem avaliar a rugosidade, composição química, presença de compostos metálicos, não metálicos, impurezas advindas da fabricação e a espessura da camada de óxidos. Esses fatores interferem na futura osseointegração. (KASEMO, LAUSMAA, 1986)
O objetivo deste trabalho foi avaliar a superfície dos implantes após a instalação em osso artificial.
2 - METODOLOGIA
2.1 Material
Esse Estudo Experimental in vitro, utilizou implantes com tratamento de superfície, de ataque ácido, duplo ataque ácido e anodizado.
IMPLANTES
Quinze implantes de superfícies diferentes foram testados. Cinco implantes Titamax da Neodent 3.75x11mm (SP/Brasil) ataque ácido, cinco implantes Strong SW 3.75x11.5mm de duplo ataque ácido da SIN (SP/Brasil) e cinco implantes Vulcano-actives 3.75x11.5mm da Conexão Sistemas de Prótese (SP/Brasil) de superfície anodizada.
OSSO ARTIFICIAL
Quinze blocos de poliuretano de 40 pound per cubic foot (PCF) com uma densidade de 0,70 – 0,75g/cm³, osso artificial (Nacional-Jahu-SP-Brasil) correspondente ao osso D1, D2, amplamente utilizado em testes mecânicos de dispositivos na Odontologia e Ortopedia, fabricados segundo a norma ASTM F 1839-01, foram cortados nas medidas de 15x15x20mm. Cada bloco foi partido no sentido longitudinal. As duas metades do bloco foram unidas e pressionadas através de uma morsa para suporte (Ferro Cinzento - FC 150– Somar, Joinville, Brasil).
2.2. Método
IDENTIFICAÇÃO DA ÁREA ESTUDADA
Uma marca de identificação foi feita no hexágono externo com uma ponta esférica diamantada, tamanho 1010 (Kavo Burs, Joinville/SC Brasil). Três diferentes áreas foram observadas no Microscópio Eletrônico de Varredura - MEV (modelo TM3000, marca Hitashi, EUA), terço cervical, médio e apical. As imagens
foram capturadas nos aumentos de x1000, x2000 e x3000 com uma voltagem de aceleração de 15kV.
INSTALAÇÃO DOS IMPLANTES
A interface do bloco de osso, foi intrumentada com brocas específicas de cada empresa a 800rpm em sequência, como recomenda cada fabricante. Os implantes foram instalados no osso artificial a 18rpm. O torque máximo não ultrapassou 45Ncm. Depois de instalados, o bloco de osso artificial foi separado em duas metades para retirar os implantes.
Os implantes foram aparafusados aos seus transferentes de moldagem para facilitar a sua remoção do bloco de osso artificial, sem que houvesse toque na sua superfície e inseridos em uma mesa de acrílico confeccionada nas medidas de 5x5x15cm com cinco perfurações nas medidas de 0,5cm, para evitar qualquer contato ou danos às suas superfícies. A mesa de acrílico com os implantes foi então inserido na cuba ultrassonica em água destilada 2cm abaixo da superfície durante dez minutos. (Figura 1). Logo após os implantes terem sido lavados, o conjunto mesa de acrílico mais implantes foram levados para uma estufa (De Leo, Porto Alegre/RS Brasil) a 37° por 24horas. Os blocos osseos foram armazenados para leitura em Espectroscopia de Energia Dispersiva – EDS (modelo SwiftED 3000, marca Hitashi, EUA).
Figura 1: Implantes aparafusados aos seus tranferentes, inseridos na mesa de acrílico.
ANÁLISE DAS SUPERFÍCIES
As superfícies dos implantes foram analisadas novamente em MEV na mesma porção de área marcada no terço cervical, médio e apical, nos mesmos aumentos e velocidade. Os blocos de osso artificial foram analisados nas áreas das roscas com EDS com a finalidade de estudar presença de partículas e detritos.
Local
Faculdade de Odontologia da UFF, Laboratório de Biotecnologia Aplicada (LABA) - Setor Mecânica.
Faculdade de Geoquímica da UFF – Laboratório Microscopy Center (MICRON).
Métodos de Avaliação
G1- 5 implantes Titamax da Neodent de ataque ácido. G2 - 5 implantes Strong SW da SIN de duplo ataque ácido.
G3 - 5 implantes Vulcano da Conexão Sistemas de Prótese de superfície anodizada.
As observações em microscopia eletrônica de varredura mostraram as alterações estruturais na superfície dos implantes e o EDS mostrou micropartículas na superfície do osso. Uma análise visual foi minunciosamente realizada qualificando as diferenças encontradas.
3 - ARTIGOS PRODUZIDOS
EVALUATION OF IMPLANT SURFACE MODIFICATIONS POST-INSERTION – A LABORATORY STUDY.
Daniel de Mattos Salim1 Waldimir Carvalho2
José Henrique Cavalcanti Lima3 Cresus Vinicius Depes de Gouvêa4
1 Mestrando em Clínica Odontológica - UFF, Esp. em Implantodontia – UFF 2 Professor Assistente UFF
3 Fundação Oswaldo Cruz
4 Professor Titular - Livre docente.
*Corresponding author: Daniel de Mattos Salim; Adress; Benevenuto Soares
Street, 19F, Zip code:24120-040 - Fonseca – Niterói – RJ - Brazil. Cel: (21) 998480983. E-mail: danielmsalim@gmail.com
ABSTRACT
Aim: To evaluate the surface of implants after installation in polyurethane (synthetic bone) and the potential implications of particle debris on these surfaces. Methodology: Fifteen commercial implants with surfaces that were anodized (5), dual acid-etched (5) and acid-etched (5) were inserted into blocks of synthetic polyurethane bone with a density corresponding to D1, D2, using burs specific to implant insertion. A perforation was made at the interface between each half of the synthetic bone, with a maximum torque of 45Ncm. The macro- and microscopic deformations of the implants were evaluated both before and after insertion, under a Scanning Electron Microscope (SEM). After insertion, the bone blocks were separated into two halves and evaluated via SEM and Energy Dispersive Spectroscopy (EDS). Results: SEM revealed damage to the implant surfaces, post-insertion. Anodized implant surfaces exhibited widespread damage, where a part of the oxide layer was removed at the thread crest, exposing the underlying material. In the polyurethane blocks where anodized implants had been installed, titanium particles were located, in a variety of sizes. Conclusion: The present study demonstrated damage to the surface, post-insertion, of anodized implants in blocks of polyurethane, associated with titanium particles at the interface. There were no significant changes where the implants were acid-etched or dual acid-etched.
1 - INTRODUCTION
Osseointegration is the physical contact between the body of the implant and the surrounding living bone. The surface of modern implants has been treated with the aim of improving osseointegration.1
Surface treatment affords implants a degree of roughness superior to the machined implant. The primary stability of the implant is a prerequisite for the implant’s survival thus preventing the formation of a layer of conjunctive tissue between implant and bone, consequently assuring the healing of the bone.2
Surface treatment can be divided into groups. The first is composed of implants coated in hydroxyapatite while the second group comprises blasting with abrasive particles, acid-etching or the deposition of titanium oxide particles. A third group receives thermochemical treatment to activate the titanium surface and increase the thickness of the oxide layer; the fourth group is used for machined implants.3
The characteristics of biomaterials, such as surface topography, surface loads, components, chemical states and wettability, have an impact on the interactions on the bone matrix, osteoblasts and biomaterials.4-5
The results of a number of studies suggest that a series of factors influences the primary stability of dental implants, such as bone quantity and density in the area
where the implant is inserted,6 surgical technique, i.e. the correlation between the size of the bur and the size of the implant7 and the microscopic and macroscopic morphology of the implant used.8-9
Successful osseointegration depends on the material employed, the manufacturing process, machining conditions, implant morphology, bone type, surgical technique, preparation of the prosthesis and the load conditions imposed during chewing.10-11
Surface evaluation techniques such as Energy Dispersive Spectroscopy (EDS) and Scanning Electron Microscopy (SEM) make it possible to identify differences between implant surfaces, either with or without surface treatment. These techniques can evaluate roughness, chemical composition, presence of metallic compounds, non-metallic compounds, impurities arising in the manufacturing process and the thickness of the oxide layer. These factors interfere with subsequent osseointegration.12
The aim of this study is to evaluate the effects on the surface of implants after installation in the synthetic bone.
2 - MATERIALS AND METHODS
2.1 Material
This in vitro Experimental Study made use of implants with acid-etching, dual acid-etching and anodized implant surface treatment.
IMPLANTS
Fifteen implants with different surfaces were tested: five 3.75x11 mm etched Titamax implants by Neodent (SP/Brazil), five 3.75x11.5 mm dual acid-etched Strong SW implants by SIN (SP/Brazil) and five 3.75x11.5 mm anodized surface Vulcano-Active implants by Conexão Sistemas de Prótese (SP/Brazil).
SYNTHETIC BONE
Fifteen 40 pound per cubic foot (PCF) polyurethane blocks with a density of 0.7 - 0.75g/cm³, synthetic bone (Nacional, Jahu, SP, Brazil) corresponding to bone densities D1, D2, widely used in mechanical testing of devices in Dentistry and Orthopedics, manufactured according to the ASTM standard F1839-01, were cut into pieces measuring 15x15x20 mm. Each block was separated in a lengthwise direction. The two halves of the block were joined and pressed using a vice for support (Ferro Cinzento, FC 150, Somar, Joinville, Brazil).
2.2. Method
IDENTIFICATION OF THE AREA STUDIED
An identification mark was made on the outer hexagon with a size 1010 spherical diamond tip (Kavo Burs, Joinville, SC, Brazil). Three different areas, the cervical, middle and apical thirds, were observed under SEM, the Scanning Electron Microscope (Hitachi TM3000, USA). The images were captured at magnifications of 1000x, 2000x and 3000x with an acceleration voltage of 15kV.
INSTALLATION OF IMPLANTS
The interface of the bone block was instrumented, with burs specific to each company, in sequence, at 800rpm, in accordance with each manufacturer’s recommendations. The implants were inserted into the synthetic bone at 18rpm. Maximum torque did not exceed 45Ncm. Once inserted, the synthetic bone block was separated into two halves to remove the implants.
The implants were screwed to their transfer molds to facilitate the removal of the block of synthetic bone, without touching the surface, and were inserted into an acrylic table measuring 5x5x15 cm with five 0.5 cm perforations to avoid any contact or damage to its surfaces. The acrylic table, along with the implants, was then inserted into the ultrasonic bath in distilled water at a depth of 2 cm for ten minutes. The blocks of bone were then washed, and the acrylic table plus implant assembly was transferred to an oven (De Leo, Porto Alegre/RS, Brazil) at 37°C for 24 hours.
The bone blocks were stored for reading under an EDS, or Energy Dispersive Spectroscope (Hitachi Swift ED 3000, USA).
SURFACE ANALYSIS
The implant surfaces were once again analyzed under SEM in the portion of the area marked on the cervical, middle and apical thirds, with the same magnifications and velocity.
The synthetic bone blocks were analyzed in the areas of the screw thread, using EDS, with the aim of studying the presence of particles and detritus.
3 - Results
The visual analysis of the scanning electron microscope images showed a differential qualitative pattern in the groups selected for this study.
For the Scanning Electron Microscope (SEM) analysis, a voltage acceleration of 15kV was used with magnifications of 2000x and 3000x and an ambient temperature of 16°C. In addition, Energy Dispersive Spectroscopy (EDS) was performed on several polyurethane blocks in order to examine with greater precision potential particles of debris, carrying out a mapping of the titanium nanoparticles.
The SEM images of the implants with acid-etched and dual acid-etched surface treatment did not exhibit any significant alterations over the entire surface, post-insertion (Figures 1a, 1b, 2a and 2b).
Figure 1a – Neodent – Acid-etched; region of the body, pre-inserted with whole
surface layer (2000x).
Figure 1b – Neodent – Acid-etched; region of the body, post-inserted, surface layer
Figure 2a – SIN – Dual acid-etched; region of the body, pre-inserted with whole surface layer (2000x).
Figure 2b – SIN – Dual acid-etched; region of the body, post-inserted, surface layer
maintained (2000x).
The SEM images of the anodized implants exhibited significant alterations in surface integrity after implant insertion. (Figures 3a, 3b, 3c and 3d).
Figure 3a – Conexão – anodized; platform region, pre-inserted with whole surface
layer (2000x).
Figure 3b – Conexão – anodized; platform region, post-inserted with removal of part
Figure 3c – Conexão – anodized; region of the body, post-inserted with removal of a
part of the surface layer (2000x).
Figure 3d – Conexão – anodized; apex region, post-inserted with removal of part of
the surface layer (2000x).
The EDS mapping was carried out on three synthetic bone blocks, one block per implant. No metal particles were detected in the synthetic bone blocks of the implants treated with acid-etching and dual acid-etching. However, titanium nanoparticles were found in the synthetic bone block where anodized implants had been installed. A higher concentration of particles was observed in the region of the thread crests (Figures 4a and 4b).
Figures 4a and 4b - EDS images (a) titanium nanoparticles were found in the
synthetic bone blocks where the anodized implants had been installed. (b) The scale of the chemical elements present (4000x).
4 - Discussion
The bone remodeling process maintains the mechanical integrity of the bone implant system. The interaction between bone resorption and bone formation is important for an understanding of the changes that occur in the bone around the implant, which are potentially responsible for the system’s mechanical stability.13
The present study demonstrated that some surface treatments may release metal particles into the bone. Damage to the TiO2 oxide layer, corrosion and dissolution of metal ions into the oral region may affect the integration of the bone tissue and implant, and are considered factors that contribute to bone integration failure.14
The presence of titanium particle residue may stimulate local and systemic cell reactions. Chemokines, such as IL-8, MCP-1, MIP-1a, amongst others, are released by acute and chronic inflammatory cells. These chemokines normally amplify the inflammatory response.15
The debris released in a single implant installation is at such a low level that it is unlikely to cause a problem, however the implants that fail release more titanium particles than can be monitored through the lymphatic nodules.16
The primary stability of an implant is a prerequisite for bone healing2,17 and various techniques based on the alteration of implant surfaces have been tested over recent years.18 The success of any osseointegration is related to the topography of
the implant surface.19 A rough surface topography provides a larger area for bone anchorage than a smooth surface.18
In this study, the uniformity of the implant surface was studied using scanning electron microscopy prior to the installation of the implants and this acted as a control in the analysis of the surfaces studied, as is the case in other studies.20,14
Dual acid-etching produces a roughness that favors an increase in the area of contact between the bone and implant. The function of the initial acid-etching is to alter the micromorphology and the second permits the formation of a uniform, more stable surface.21 The roughness of any surface plays an important role in implant behavior given the interactions with the mediated proliferation/differentiation of cells, synthesis of the extracellular matrix and cell morphology.22
SEM images of the acid-etched and dual acid-etched implant surfaces showed no significant change in surface integrity, post-insertion. The studies by SALERNO et al., 201519 and SRIDHAR et al., 201614, corroborate these findings, stating that no relevant changes occurred in the surface topography of the implants, post-installation.
Treatment via anodization has become a favorite option in clinical use as it incorporates calcium and phosphate into the titanium oxide, increasing the osteoblast response and, consequently, accelerating the healing process. This treatment causes a significant alteration in the morphology of the implant surface, since the titanium oxide grows in the shape of tiny volcanoes of varying sizes and heights, thereby causing an increase in roughness.21 The findings of the present study confirm this assertion. Figures 3a, 3b, 3c and 3d exhibit a surface with small pits that
vary in size and height, providing a large area of contact between the bone and implant.
The SEM images, after the insertion of the implants using anodized surface treatment, showed significant alterations in surface integrity, losses and cracks, as shown in the study by MINTS et al., 2014.20
Several studies have stated that the mechanical forces involved in the process of implant installation do not result in premature exfoliation of the surface’s oxide layer.14,23 It was not possible to confirm this assertion in the present study nor in a separate study that showed surfaces that were susceptible to breaking on installation.20,15-16
The EDS mapping was performed on three blocks of synthetic bone, one for each type of surface inserted. No metallic particles were detected in the blocks of synthetic bone that had been in contact with acid-etched and dual acid-etched implants.
The elementary composition of the implant surface mainly consists of titanium (Ti), oxygen (O) and carbon (C).14 In this study, nanoparticles of titanium (Ti), oxygen (O) and carbon (C) were found in blocks of synthetic bone of the anodized implants. A higher concentration of particles was observed in the area of the thread crest. In the blocks associated with the acid-etched and dual acid-etched implants, only oxygen (O) and carbon (C) nanoparticles were found.
A separate in vitro study reported damage as a result of the process of insertion into the implant surfaces (fabricated in the in-house laboratory) in synthetic bone, stating that alterations could only be found, with any degree of clarity, in the
surfaces of the anodized implants. The oxide layer thickness was stripped away, mainly at the tops of the crests and the apical region, associated with loose titanium particles.20 This corroborates the data found in the current study using commercial implants.
In this research study, there was a significant loss of anodized surface, however this loss may not be significant in terms of the osseointegration process. One study concluded that anodized, acid-etched surfaces behaved similarly with regard to primary and secondary stability when the implants installed in the posterior mandibular region were not subjected to immediate or premature loads.24
Studies show that polyurethane-based synthetic bone can simulate studies with implants inserted into trabecular bone.25 The American Society for Testing and Materials (ASTM)26 approves the use of the polyurethane block in the study of osseointegrated implants (ASTM F543, 2007), even where the synthetic bone possesses an internal geometry different from that of natural bone in terms of trabecular distribution, size and shape. This material is being increasingly used by researchers.27
Other studies, such as that of SRIDHAR, 2016,14 MINTS et al., 2014,20 TABASSUM et al., 2010,17 and CALVERT et al., 2010,27 used synthetic polyurethane blocks of bone to test osseointegrated implants. TABASSUM et al.17 and MINTS et al.20 opted to use 30 grade PFBS blocks with a density of 0.48 g/cm3, which are similar to bone type 3 or 4.28 The present study used 40 pcf synthetic bone with a density of 0.7 – 0.75g/cm³, similar to bone density types 1 and 2 28
similar to the type of bone in the mandibular, according to the classification of MISCH, 2008.11
Clinical monitoring studies are needed in order to test the hypothesis that loose particles in the bone can cause complications.
5 - CONCLUSIONS
Based on the methodology employed, on the experimental conditions and in accordance with the proposal, the following conclusion may be drawn:
It is legitimate to state that some of the implant surfaces tested in this study exhibited damage as a result of the insertion process.
Implants receiving acid-etching and dual acid-etching treatment did not demonstrate significant alterations.
Surface changes were found in the anodized implants, mainly at the thread crests, associated with loose titanium particles found in the synthetic bone blocks.
ACKNOWLEDGMENTS
The authors declare to have no conflict of interest regarding this study.
6- REFERENCES
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3 Elias, CN et al. Diferentes superfícies dos implantes dentários. In: III Congresso Latino Americano de Órgãos Artificiais e Biomateriais, 2004,Campinas.
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4 - CONCLUSÕES
Com base na metodologia aplicada, nas condições experimentais e em conformidade com a proposição, conclui-se que:
É licito afirmar que algumas superfícies de implantes testados neste estudo, demonstraram danos como resultados do processo de inserção.
Implantes com tratamento de ataque ácido e duplo ataque ácido não apresentaram mundaças significativas.
Alterações de superfície foram encontradas nos implantes anodizados, principalmente nas cristas das roscas, associadas com partículas de titânio soltas encontradas nos blocos de osso artificial.
