Analysis of implants with laser irradiated surface and silicate deposition

Objectives: the purpose of this study was to evaluate the surfaces of commercially pure titanium (cpTi) implants surface modified by laser beam (LS), by laser beam associated with sodium silicate deposition (SS) and compare them with surfaces modified by dual-acid etched (AS) and with machined surface (MS). Methods: thirty rabbits received two implants each (one for each tibia). After 30, 60 and 90 days postoperative, the implants were removed by reverse torque for biomechanical analysis and surfaces were analyzed by scanning electron microscopy (SEM) and X-ray energy dispersive spectroscopy (EDS). Results: the mean values of reverse torque at 30, 60 and 90 days postoperative were respectively 24.60, 43.60 e 60.40 N.cm to MS, 43.00, 68.20 e 63.80 N.cm to AS group, 59.80, 76.60 e 78.00 N.cm to LS group and 63.00, 75.40 e 76.60 N.cm to SS group. At 30 days, LS and SS groups showed statistically significant difference (p<0.05) compared to the other groups. At 60 days, LS and SS groups showed statistically significant difference (p<0.05) when compared to MS. Conclusions: it was concluded that SL and SS implants' biomechanical and topographical properties increased bone-implant interaction when compared to the AS and MS implants.

Efeito da aplicação de filmes de carbono tipo diamante por plasma no destorque de pilares de implantes com conexões cônicas internas

Pós-graduação em Odontologia Restauradora - ICT

Efeito da administração de alendronato, a longo prazo, sobre as propriedades mecânicas do tecido ósseo, sua reparação e mineralização ao redor de implantes osseointegráveis. Estudo em ratas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desenvolvimento de parafuso de interferência bioabsorvível para cirurgia de joelho em PLDL (poli ácido lático) e compósito PLDL + βTCP (beta trifosfato de cálcio)

Pós-graduação em Engenharia Mecânica - FEB

Carbono tipo diamante em componentes de implantes dentários: avaliação das propriedades antimicrobianas e de adesão de Escherichia coli

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência dos parâmetros de projeto em um motor a combustão interna

This paper discusses the influence of the design parameters in the operation and construction of an internal combustion engine. A theoretical analysis was developed using a standard crank-connecting rod-piston to verify the behavior of the stresses generated in the combustion and transformed into rotational energy of the crank shaft. Design parameters directly influence not only the final result of the characteristics of power and torque, but how the engine must be built to withstand different loads. The choice of parameters of a combustion engine is directly linked with the application of the engine and the final result expected of it function

Relationship between the surface chemical composition of implants and contact with the substrate

The purpose of the study was to use scanning electron microscopy and energy dispersive x-ray spectrometry to assess possible morphologic and chemical changes after performing double-insertion and pullout tests of implants of different shapes and surface treatments. Four different types of implants were used—cylindrical machined-surface implants, cylindrical double-surface–treated porous implants, cylindrical surface-treated porous implants, and tapered surface-treated porous implants—representing a total of 32 screws. The implants were inserted into synthetic bone femurs, totaling 8 samples, before performing each insertion with standardized torque. After each pullout the implants were analyzed by scanning electron microscopy and energy dispersive x-ray spectrometry using a universal testing machine and magnified 35 times. No structural changes were detected on morphological surface characterization, only substrate accumulation. As for composition, there were concentration differences in the titanium, oxygen, and carbon elements. Implants with surface acid treatment undergo greater superficial changes in chemical composition than machined implants, that is, the greater the contact area of the implant with the substrate, the greater the oxide layer change. In addition, prior manipulation can alter the chemical composition of implants, typically to a greater degree in surface-treated implants.

Effect of splinting in accuracy of two implants impression techniques

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Reabilitação estético-funcional sobre implantes agulhados e endósseos

This report shows the resolution of a case study whose aim was promote the aesthetic and functional rehabilitation of upper left hemi-arch over endosseous and needle implant prostheses. To improve the position of the needle implants, we performed the bucco-palatal bending of needles splinting them with composite resin; we removed the screwed implant prosthesis in the regions of the premolars (24 and 25) and molar (26). The mini-abutments of the last two implants were replaced, and in the first premolar and canine, we used cemented abutments due to implant angulation having planned soldering because of implant size and contact with one needle implant that could interfere with intimate contact bone/implant damaging biomechanics. Pick-up impressions were performed with an open tray, using a retractor cord in the needle implants and respective transfer copings. Therefore, models were related on semi-adjustable articulator after a face-bow recording and interocclusal indexes. After working cast fabrication and try-in of infra-structures, these were adjusted and related into the articulator again. Then, after ceramic build-up, adjustments, finishing, and torque, chemically-activated resin cement was applied on units 21 to 24. At the end of the case, we concluded that a good aesthetic and functional rehabilitation depends on thorough knowledge of techniques for each clinical situation.

Comparação dos parâmetros de força e propriocepção entre indivíduos com e sem instabilidade funcional de tornozelo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo das microdeformações geradas ao redor de implantes de hexágono externo, sob a aplicação de cargas axiais e não axiais em pilares protéticos retos e angulados

Pós-graduação em Odontologia Restauradora - ICT

Avaliação do reparo ósseo na interface osso/implante em ratas com osteoporose induzida tratadas com raloxifeno ou alendronato: análise histométrica, imunoistoquímica, por epifluorescência e biomecânica

Pós-graduação em Odontologia - FOA

Raloxifene enhances peri-implant bone healing in osteoporotic rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Healing of implants installed in over- or under-prepared sites: an experimental study in dogs

ObjectiveTo study bone healing at implants installed with different insertion torques.Material and methodsIn six Labrador dogs, all mandibular premolars and first molars were extracted. After 4months of healing, flaps were elevated, and two implant sites were prepared at each side of the mandible. In the right side of the mandible, the distal sites were prepared conventionally, while the mesial sites were over-prepared by 0.2mm. As a consequence, a final insertion torque of similar to 30Ncm at the distal and a minimal insertion torque close to 0Ncm at the mesial sites were obtained. In the left sides of the mandible, however, the recipient sites were underprepared by 0.3mm resulting in an insertion torque of 70Ncm at both implants. Cover screws were applied, and flaps sutured to fully submerge the experimental sites. After 4months, the animals were sacrificed and ground sections obtained for histological evaluation.ResultsThe mineralized bone-to-implant contact was in the range of 55.2-62.1%, displaying the highest value at implants with similar to 30Ncm insertion torque and the lowest value at the implant sites with close to 0Ncm insertion torque. No statistically significant differences were revealed. Bone density was in the range of 43.4-54.9%, yielding the highest value at implants with 70Ncm insertion torque and the lowest at the implant sites with close to 0Ncm insertion torque. The difference between the sites of similar to 30Ncm and the corresponding 70Ncm insertion torque reached statistical significance.ConclusionsSimilar amounts of osseointegration were obtained irrespective of the insertion torque applied. Moreover, implants installed in sites with close to 0Ncm insertion torque may properly osseointegrate as well.

Early loading of 6-mm-short implants with a moderately rough surface supporting single crowns: a prospective 5-year cohort study

AimTo evaluate prospectively the clinical and radiographic outcomes after 5years of early loading of 6-mm implants with a moderately rough (SLActive((R))) surface supporting single crowns in the posterior regions.Material and methodsThirty-five consecutive patients received 40 SLActive((R)) (Straumann) 6-mm implants with a diameter of 4.1mm (n=19) or 4.8mm (n=21). Insertion torque and resonance frequency analysis (RFA) were measured at implant installation. RFA was also measured at abutment connection. SynOcta abutments were tightened with 35Ncm after 6weeks of healing, and single porcelain fuse to metal crowns was cemented within 1week. Implant survival rate and marginal bone loss were evaluated at various time intervals until 5years after loading. The clinical crown/implant ratio was calculated as well.ResultsTwo of 40 implants were lost before loading (incorporation rate 95%), and no further implant loss or technical complications were encountered during the 5-year follow-up period. A mean marginal bone loss of 0.70.6mm was found after 5years of function. The clinical crown/implant ratio increased with time from 1.6 at the delivery of the prosthesis to 2 after 5years of loading.ConclusionSix millimeter implants with a SLActive((R)) moderately rough surface supporting single crowns in the posterior region and loaded after 6-7weeks maintained full function for at least 5year with low marginal bone resorption.