RESUMO
This paper is aimed to present a biomaterials perspective in implant therapy that fosters improved bone response and long-term biomechanical competence from surgical instrumentation to final prosthetic rehabilitation. Strategies to develop implant surface texturing will be presented and their role as an ad hoc treatment discussed in light of the interplay between surgical instrumentation and implant macrogeometric configuration. Evidence from human retrieved implants in service for several years and from in vivo studies will be used to show how the interplay between surgical instrumentation and implant macrogeometry design affect osseointegration healing pathways, and bone morphologic and long-term mechanical properties. Also, the planning of implant-supported prosthetic rehabilitations targeted at long-term performance will be appraised from a standpoint where personal preferences (eg, cementing or screwing a prosthesis) can very often fail to deliver the best patient care. Lastly, the acknowledgement that every rehabilitation will have its strength degraded over time once in function will be highlighted, since the potential occurrence of even minor failures is rarely presented to patients prior to treatment.
Assuntos
Implantes Dentários , Materiais Biocompatíveis , Implantação Dentária Endóssea , Planejamento de Prótese Dentária , Prótese Dentária Fixada por Implante , Humanos , OsseointegraçãoRESUMO
The aim of this study was to evaluate the accuracy in volumetric measurements obtained on an experimental model using an intraoral scanner and a gravimetric method. Three identical partial dentate maxillary acrylic models with three fabricated alveolar defects, in anterior and posterior regions, were scanned using an intraoral scanner (20 scans/defects). The defects differed in terms of size and distance of neighbouring teeth. As references, replicas of each defect were created using a dimensional stable silicone impression material. After measuring the mass of each replica, the volume was calculated by dividing the mass of each replica by the density of the impression material. The defects had a volume, according to the gravimetric method, ranging from 40.5 to 143.7 mm3. The scans were imported to metrology software for analyses. Accuracy was determined in terms of trueness and precision. The mean trueness for all defect types was 0.168 mm3 (SD 0.691, range 2.82). There was no statistical significant difference between the mean trueness for all defects measured (p = 0.910). The mean precision for all defect types was 0.147 mm3 (SD 0.524, range 2.86). There were no statistical significant differences between the dental models in regard to mean precision (p = 0.401), however, there were statistical significant differences between defects in position 1 and 2 (p = 0.002) and 1 and 3 (p = 0.001). Based on the findings of this study, the intraoral scanner utilized in the current study presented an acceptable level of accuracy when measuring volume of defects.
Assuntos
Desenho Assistido por Computador , Técnica de Moldagem Odontológica , Materiais para Moldagem Odontológica , Imageamento Tridimensional , Modelos DentáriosRESUMO
OBJECTIVE: The aim of this study was to investigate the extent of cortical bone remodeling between two different drilling protocols by means of histomorphometric, µ-CT, and biomechanical analyses. MATERIAL AND METHODS: A total of 48 implants were inserted into the mandible of six sheep following two drilling protocols: Group A (Test, n = 24), undersized preparation; Group B (Control, n = 24), non-undersized preparation. The animals were euthanatized to obtain 5 and 10 weeks of implantation time. Removal torque (RTQ) was measured on 12 implants of each group and the peri-implant bone was µ-CT scanned. Bone volume density (BV/TV) was calculated in pre-determined cylindrical volumes, up to 1.5 mm from implant surface. Non-decalcified histology was prepared on the remaining 12 implants from each group, where total bone-to-implant contact (totBIC) and newly-formed BIC (newBIC) was measured. Bone Area Fraction Occupancy (BAFO) was determined in pre-determined areas up to 1.5 mm from implant surface. Paired sample t test or Wilcoxon signed-rank test was used to investigate differences between the groups. RESULTS: Group A presented significantly increased RTQ value at 5 weeks, while no difference was observed at 10 weeks. Group B presented increased BV/TV value at 5 weeks. Both groups showed comparable values for totBIC at both time-points. However, Group A presented significantly lower newBIC at 5 weeks. Higher BAFO was observed in Group B at 5 weeks. CONCLUSIONS: Implants inserted into undersized sites has an increased biomechanical performance, but provoked major remodeling of the cortical bone during the early healing period compared to non-undersized preparations. After 10 weeks, no difference was observed.
Assuntos
Osso Cortical/cirurgia , Implantação Dentária Endóssea/métodos , Mandíbula/cirurgia , Animais , Fenômenos Biomecânicos , Remodelação Óssea , Osso Cortical/anatomia & histologia , Osso Cortical/diagnóstico por imagem , Feminino , Mandíbula/anatomia & histologia , Mandíbula/diagnóstico por imagem , Osseointegração , Ovinos , Torque , Microtomografia por Raio-XRESUMO
PURPOSE: To evaluate the antifungal activity and mechanical properties of a novel antifungal tissue conditioner containing Juncus powder. MATERIALS AND METHODS: Juncus powder was mixed with GC tissue conditioner at concentrations of 2.5%, 5.0%, and 10.0% by mass. The cylindrical specimens of Juncus-mixed tissue conditioner (dimensions: 10 mm in diameter and 2 and 6 mm in height for antimicrobial and mechanical tests, respectively) were prepared. The specimens placed on the bottom of the 24-well tissue culture plate were cultured with Candida albicans CAD1 for 2 and 4 days. The proliferation of the C. albicans in the wells was determined by measuring the optical density of fungal culture, and the surface of the specimens were also observed by scanning electron microscopy (SEM). To assess the mechanical properties of the specimens, the fluidity and hardness of Juncus-mixed tissue conditioner were measured using the methods certified according to ISO 10139-1. RESULTS: Juncus-mixed tissue conditioner significantly exhibited growth inhibitory effect in a Juncus concentration-dependent manner after both 2- and 4- day cultures. SEM observation showed that the amount of C. albicans on Juncus-mixed specimens drastically decreased, and biofilm formation was markedly inhibited. Moreover, both mechanical properties were found to be within the ranges regulated and specified by ISO. CONCLUSION: These findings demonstrated that the tissue conditioner including Juncus powder has a significant growth inhibitory effect against C. albicans, and it is suggested that the application of Juncus-mixed tissue conditioner may prevent denture stomatitis and oral candidiasis in denture wearers.
Assuntos
Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Magnoliopsida , Extratos Vegetais/farmacologia , Condicionamento de Tecido Mole Oral/métodos , Biofilmes/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Técnicas In Vitro , Microscopia Eletrônica de VarreduraRESUMO
OBJECTIVES: Titanium-zirconium (TiZr) has been proposed as a mechanically stronger alternative to commercially pure titanium for oral and orthopaedic implants. However, not much is known on the osseointegration kinetics of TiZr surfaces. In this study, we aimed to identify the genetic response of bone around TiZr implants compared to pure Ti. MATERIAL AND METHODS: Microtextured and hydrophilic TiZr implants (tests) and cpTi implants grade IV (controls) were placed in the tibia of 30 New Zealand white rabbits. At 2, 4 and 12 weeks, the implants were subjected to removal torque test (RTQ). The expression of a panel of genes involved in the process of osseointegration was measured in the bone around the test and control implants by means of quantitative real-time polymerase chain reaction (PCR) and compared to the control samples. RESULTS: The controls yielded statistically significant higher RTQ at 4 weeks, but the RTQ of the tests had a larger increase between 4 and 12 weeks, when both groups reached similar values. The gene expression analysis showed that all selected markers for bone formation, bone remodelling and cytokines were significantly upregulated around TiZr implants after 2 weeks. After 4 weeks of healing, two bone formation markers were significantly more expressed in the test samples, while at 12 weeks, the expression of all genes was similar in the two groups. CONCLUSIONS: TiZr implants showed comparable biomechanical outcomes to cpTi up to 12 weeks of healing. However, at early healing stages, they showed a significant upregulation of osteogenesis and osteoclastogenesis markers.
Assuntos
Implantes Dentários , Planejamento de Prótese Dentária , Osseointegração/fisiologia , Titânio , Zircônio , Animais , Feminino , Teste de Materiais , Coelhos , Transdução de Sinais , Fatores de Tempo , Titânio/química , Zircônio/químicaRESUMO
It has been suggested that surface modification with a thin hydroxyapatite (HA) coating enhances the osseointegration of titanium implants. However, there is insufficient information about the biological processes involved in the HA-induced response. This study aimed to investigate the inflammatory cell response to titanium implants with either amorphous or crystalline thin HA. Human mononuclear cells were cultured on titanium discs with a machined surface or with a thin, 0.1 µm, amorphous or crystalline HA coating. Cells were cultured for 24 and 96 h, with and without lipopolysaccharide (LPS) stimulation. The surfaces were characterized with respect to chemistry, phase composition, wettability and topography. Biological analyses included the percentage of implant-adherent cells and the secretion of pro-inflammatory cytokine (TNF-α) and growth factors (BMP-2 and TGF-ß1). Crystalline HA revealed a smooth surface, whereas the amorphous HA displayed a porous structure, at nano-scale, and a hydrophobic surface. Higher TNF-α secretion and a higher ratio of adherent cells were demonstrated for the amorphous HA compared with the crystalline HA. TGF-ß1 secretion was detected in all groups, but without any difference. No BMP-2 secretion was detected in any of the groups. The addition of LPS resulted in a significant increase in TNF-α in all groups, whereas TGF-ß1 was not affected. Taken together, the results show that thin HA coatings with similar micro-roughness but a different phase composition, nano-scale roughness and wettability are associated with different monocyte responses. In the absence of strong inflammatory stimuli, crystalline hydroxyapatite elicits a lower inflammatory response compared with amorphous hydroxyapatite.
Assuntos
Implantes Dentários , Durapatita/química , Inflamação , Lipopolissacarídeos/química , Animais , Proteína Morfogenética Óssea 2/metabolismo , Linhagem Celular , Materiais Revestidos Biocompatíveis/química , Cristalização , Citocinas/metabolismo , Ensaio de Imunoadsorção Enzimática , Humanos , Leucócitos Mononucleares/citologia , Teste de Materiais , Camundongos , Monócitos/citologia , Osseointegração/efeitos dos fármacos , Células RAW 264.7 , Propriedades de Superfície , Titânio/química , Fator de Crescimento Transformador beta1/metabolismo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Obtaining ideal prosthetic framework design is at times hindered by anatomical limitations in the posterior region that might increase the risk for zirconia restoration fracture. Modification such as increasing the bulk thickness especially in the connector region could result in strengthening the zirconia framework. Three-unit zirconia fixed partial dentures replacing mandibular molars were fabricated using the following two techniques: CAD/CAM technology and manual copy milling. Modified framework with unveneered full thickness connectors were designed and fabricated with the aforementioned methods. Conventional frameworks (0.5 mm thick with rounded 3 mm connectors) served as control (N = 20). After cementation on epoxy dies, the frameworks were loaded to fracture in a universal testing machine. Fractured surfaces were prepared for examination using scanning electron microscopy. Statistical analysis revealed significant differences in fracture resistance between conventional and modified framework design for both fabrication techniques tested. SEM examination indicated that critical crack originated at the tensile surface of the connectors for conventional frameworks. The critical crack for modified frameworks occurred on the axial wall of the abutments. The modification of the zirconia framework design presented significant improvement of the fracture resistance compared to the conventional design.
Assuntos
Falha de Restauração Dentária , Planejamento de Dentadura , Prótese Parcial Fixa , Zircônio/química , Dente Pré-Molar , Desenho Assistido por Computador , Materiais Dentários/química , Análise do Estresse Dentário , Humanos , Técnicas In Vitro , Mandíbula , Microscopia Eletrônica de Varredura , Dente MolarRESUMO
INTRODUCTION: Contamination during surgery negatively influences the prognosis of orthopaedic implants; however, it has not been proven whether contamination influences the success of dental implant treatment. The aim of the systematic review was to investigate if there exists evidence in the literature whether contamination of dental implants during surgery affects osseointegration and clinical success. MATERIALS AND METHODS: Four data bases were used for the literature search. Primary studies and reviews regarding both clinical and preclinical research were eligible. Rating of the summarized quality of the evidence was performed. RESULTS: Five preclinical studies were included. Because of the estimated high risk of bias in all included studies and extensive differences in study design between the included studies, meta-analysis was not performed and no reliable aggregated data could be extracted. CONCLUSIONS: It is suggested that the scientific evidence with regard to the current topic is insufficient. Further controlled studies are warranted.
Assuntos
Implantação Dentária Endóssea/microbiologia , Infecção da Ferida Cirúrgica/etiologia , Implantação Dentária Endóssea/efeitos adversos , Implantes Dentários/efeitos adversos , Implantes Dentários/microbiologia , Humanos , Infecção da Ferida Cirúrgica/microbiologiaRESUMO
PURPOSE: Based on the current evidence, the effect of implant macrogeometry has a significant influence on osseointegration. Thus, this study evaluated histomorphometrically and histologically the bone response to acid-etched in comparison to grit-blasted/acid-etched (GB) and machined control (C) surfaced implants possessing identical macrogeometry placed in high-density bone. MATERIALS AND METHODS: Implant surface topography of the 3 different surfaced implants has previously been characterized. The macrogeometry of the implants were conical, and healing chambers were created in the cortical regions. The 3 groups were placed in the external mandibular body of adult male sheep (n = 5). After 6 weeks in vivo, all samples were retrieved for histologic observation and histomorphometry (eg, bone-to-implant contact [BIC] and bone area fraction occupancy [BAFO]). RESULTS: No statistical difference was observed for BIC and for BAFO, although there was a tendency that the mean values for BAFO was higher for the textured surface groups. CONCLUSIONS: It is suggested that the effect of surface topography is minimal in high-density bone and osseointegration seemed to be macrogeometry dependent.
Assuntos
Corrosão Dentária/métodos , Implantes Dentários , Mandíbula/cirurgia , Osseointegração/fisiologia , Condicionamento Ácido do Dente , Animais , Densidade Óssea , Interface Osso-Implante , Implantação Dentária Endóssea , Planejamento de Prótese Dentária , Carneiro Doméstico , Propriedades de SuperfícieRESUMO
OBJECTIVE: To evaluate in vitro the sealing capability at the prosthetic connection interface of 2 conometric systems. MATERIALS AND METHODS: Two conometric systems with the same design and different material were used, for a total of 24 samples. Each sample was assembled by a tapered abutment and respective coping. In group A, the copings were made of gold, whereas in group B they were made of PEEK. Three µL of mix bacterial suspension (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Fusobacterium nucleatum species) was inoculated into the abutment screw hole, and the coping was inserted on the abutment. Samples were immersed into culture tubes and incubated for 24, 48, and 72 hours into anaerobic conditions. Visual evaluation of turbidity was performed at each time point. Qualitative-quantitative assessment using real-time polymerase chain reaction was performed at 72 hours. Any difference between the groups was checked by means of Fisher exact test. RESULTS: Microbial leakage occurred in both groups, and there was no statistically significant difference between groups. Microbial concentration resulted in a presence inferior to 1 × 10 copies/µL in all positive assemblies. CONCLUSIONS: Because of the low bacterial count, it can be concluded that a minimal bacterial infiltration may be allowed by conometric interfaces for prosthetic connection.
Assuntos
Dente Suporte , Implantes Dentários/microbiologia , Infiltração Dentária/microbiologia , Aggregatibacter actinomycetemcomitans , Dente Suporte/efeitos adversos , Projeto do Implante Dentário-Pivô/efeitos adversos , Fusobacterium nucleatum , Humanos , Técnicas In Vitro , Porphyromonas gingivalisRESUMO
AIM: To investigate how osseointegration is affected by different nano- and microstructures. The hypothesis was that the surface structure created by dual acid treatment (AT-1), applied on a reduced topography, might achieve equivalent biomechanical performance as a rougher surface treated with hydrofluoric acid (HF). MATERIALS AND METHODS: In a preclinical rabbit study, three groups (I, II, and III) comprised of test and control implants were inserted in 30 rabbits. The microstructures of the test implants were either produced by blasting with coarse (I) or fine (II) titanium particles or remained turned (III). All test implants were thereafter treated with AT-1 resulting in three different test surfaces. The microstructure of the control implants was produced by blasting with coarse titanium particles thereafter treated with HF. The surface topography was characterized by interferometry. Biomechanical (removal torque) and histomorphometric (bone-implant contact; bone area) performances were measured after 4 or 12 weeks of healing. RESULTS: Removal torque measurement demonstrated that test implants in group I had an enhanced biomechanical performance compared to that of the control despite similar surface roughness value (Sa ). At 4 weeks of healing, group II test implants showed equivalent biomechanical performance to that of the control, despite a decreased Sa value. Group III test implants showed decreased biomechanical performance to that of the control. CONCLUSIONS: The results of the present study suggest that nano- and microstructure alteration by AT-1 on a blasted implant might enhance the initial biomechanical performance, while for longer healing time, the surface interlocking capacity seems to be more important.
Assuntos
Implantação Dentária Endóssea/métodos , Implantes Dentários , Planejamento de Prótese Dentária , Osseointegração , Animais , Fenômenos Biomecânicos , Remoção de Dispositivo , Feminino , Ácido Fluorídrico , Implantes Experimentais , Nanoestruturas , Ácido Oxálico , Coelhos , Propriedades de Superfície , Tíbia , Titânio/química , TorqueRESUMO
OBJECTIVES: When implants are inserted, the initial implant stability is dependent on the mechanical stability. To increase the initial stability, it was hypothesized that bone condensation implants will enhance the mechanical stability initially and that the moderately rough surface will further contribute to the secondary stability by enhanced osseointegration. It was further hypothesized that as the healing progresses the difference in removal torque will diminish. In addition, a 3D model was developed to simulate the interfacial shear strength. This was converted to a theoretical removal torque that was compared to the removal torque obtained in vivo. MATERIAL AND METHODS: Condensation implants, inducing bone strains of 0.015, were installed into the left tibia of 24 rabbits. Non-condensation implants were installed into the right tibia. All implants had a moderately rough surface. The implants had an implantation time of 7, 28, or 84 days before the removal torque was measured. The interfacial shear strength at different healing time was estimated by the means of finite element method. RESULTS: At 7 days of healing, the condensation implant had an increased removal torque compared to the non-bone-condensation implant. At 28 and 84 days of healing, there was no difference in removal torque. The simulated interfacial shear strength ratios of bone condensation implants at different implantation time were in line with the in vivo data. CONCLUSIONS: Moderately rough implants that initially induce bone strain during installation have increased stability during the early healing period. In addition, the finite element method may be used to evaluate differences in interlocking capacity.
Assuntos
Remodelação Óssea , Implantes Dentários , Animais , Implantação Dentária Endóssea/métodos , Remoção de Dispositivo , Análise de Elementos Finitos , Coelhos , Resistência ao Cisalhamento , Propriedades de Superfície , Tíbia , TorqueRESUMO
BACKGROUND: One of the crucial aspects in guided bone regeneration is the space maintenance. This is normally created by a membrane, which should primarily be accepted by the surrounding tissues without causing any adverse reactions. The impact of surface topography, biological acceptance as well as permeability of these membranes has been carefully discussed in the literature. PURPOSE: The purpose of this study was to evaluate histologically the bone forming properties inside of hollow hydroxyapatite space-maintaining devices with different inner surfaces and different permeabilities in an animal calvaria model in vivo. MATERIALS AND METHODS: A total of 36 hollow domes with three different designs made of hydroxyapatite were surgically attached to the skulls of rabbits. Group 1 had a moderately rough inner surface. Group 2 had a smooth inner surface. Group 3 had the same properties as Group 1 but had macroscopic holes on the top. The domes were left to heal for 12 weeks and were then processed for undecalcified ground sectioning. Histological evaluations were performed using a light microscope and scanning electron microscopy. The bone-implant contact (BIC) percentage along the device was calculated. RESULTS: The median percentage of BIC was higher for Group 1 compared with Group 2 (P = 0.004). Group 1 produced a larger median BIC compared with Group 3 (P < 0.0001). CONCLUSIONS: Within the limits of this preclinical study, these findings suggest that a moderately rough inner surface of a ceramic membrane along with a non-permeable device produces more bone than a smooth inner surface.
Assuntos
Regeneração Óssea , Durapatita , Regeneração Tecidual Guiada/métodos , Membranas Artificiais , Propriedades de Superfície , Animais , Materiais Biocompatíveis , Microscopia Eletrônica de Varredura , Coelhos , Crânio/cirurgiaRESUMO
PURPOSE: To understand the bone modeling/remodeling process of functionally loaded implants by observing the alignment of the biological apatite (BAp) c-axis. MATERIALS AND METHODS: Commercially available titanium implants with TiO2 grit-blasted surfaces were placed in the fourth premolar and the first molar of the beagle dog and were functionally loaded with casted crowns and were compared to the non-loaded controls. After being killed, the samples were subjected to histological observation and to a microbeam x-ray diffraction (µXRD) analysis with a transmission optical system to evaluate the preferential BAp c-axis alignment. RESULTS: The non-loaded group presented mostly nonoriented BAp c-axis around the implant, whereas for the loaded group, preferential alignment of BAp c-axis was observed along the loading direction of the implant suggesting that the Bap aligned itself based on the direction of the functional mechanical loading. CONCLUSION: The µXRD revealed that the c-axis orientation was perpendicular to the implant thread working against the functional loaded direction, which may contribute in designing an optimal implant macrogeometry.
Assuntos
Apatitas/uso terapêutico , Remodelação Óssea , Implantação Dentária Endóssea/métodos , Animais , Materiais Biocompatíveis/uso terapêutico , Interface Osso-Implante/patologia , Implantes Dentários , Cães , Feminino , Titânio , Suporte de Carga , Difração de Raios X/métodosRESUMO
PURPOSE: To compare the bone bonding capabilities of 2 different surface treatments at an early healing period. Titanium alloy (Ti6Al4V) custom-made rectangular plates (1.4 × 2.4 × 4 mm) were either dual acid etched (Ti6Al4V-DAE) or DAE/nanotextured blasted (Ti6Al4V-NTB). MATERIALS AND METHODS: Implants were placed in the distal femurs of 10 Wistar rats and were allowed to heal for 9 days. After euthanasia, the bone immediately proximal and distal to the implant was removed to test the bone bonding force with a universal testing machine. Ultrastructure of the bone/implant interface was assessed by scanning electron microscopy. RESULTS: Ti6Al4V-NTB samples exhibited significantly greater bond strength than Ti6Al4V-DAE samples. Morphologically, the Ti6Al4V-NTB surfaces presented intimate interaction with bone, whereas little interaction between the Ti6Al4V-DAE surface and bone was observed. CONCLUSION: The results of this study indicated a significant increase in bone bonding for the DAE/nanotextured blasted surface, which is suggested to be the outcome of the nanotexturing.
Assuntos
Colagem Dentária/métodos , Implantação Dentária/métodos , Condicionamento Ácido do Dente/métodos , Ligas , Animais , Fêmur/cirurgia , Masculino , Nanotecnologia/métodos , Osseointegração , Ratos , Ratos Wistar , Propriedades de Superfície , Resistência à Tração , Titânio/uso terapêuticoRESUMO
PURPOSE: To investigate the causes for internal implant fractures, which is suggested to be one of the reasons for marginal bone loss. MATERIALS AND METHODS: From a 14-year database of 6051 implants, 10 single implant vertical fractures were identified and the abutments were all castable abutments. The abutments presented contamination and irregularities at the internal connecting areas. The hypothesis was that perfect fit was disturbed by laboratory polishing procedures, and finite element analysis (FEA) using overcorrected and undercorrected castable abutment models were created and tested against a perfect fit model. RESULTS: The results from the FEA presented that both overcorrected and undercorrected models presented nonuniform excessive plastic strain distribution in the neck portion of the implants where clinically an implant fracture was noted. CONCLUSIONS: The results suggested that laboratory procedures could induce plastic strain of the implant-abutment complex, which increases the risk of fracture.
Assuntos
Implantes Dentários/efeitos adversos , Dente Suporte/efeitos adversos , Projeto do Implante Dentário-Pivô , Falha de Restauração Dentária , Análise do Estresse Dentário , Análise de Elementos Finitos , HumanosRESUMO
OBJECTIVES: The objective of this histologic study was to determine the effect of three drilling protocols (oversized, intermediate, and undersized) on biologic responses to a single implant type at early healing periods (2 weeks in vivo) in a beagle dog model. MATERIALS AND METHODS: Ten beagle dogs were acquired and subjected to surgeries in the tibia 2 weeks before euthanasia. During surgery, each dog received three Unitite implants, 4 mm in diameter by 10 mm in length, in bone sites drilled to 3.5, 3.75, and 4.0 mm in final diameter. The insertion torque was recorded during surgery, and bone-to-implant contact (BIC), and bone area fraction occupied (BAFO) measured from the histology. Each outcome measure was compared between treatment conditions with the Wilcoxon signed-rank test. Bonferroni-corrected statistical significance was set to 95%. RESULTS: Insertion torque increased as an inverse function of drilling diameter, as indicated by significant differences in torque levels between each pair of conditions (P = 0.005). BIC and BAFO levels were highest and statistically similar in the recommended and undersized conditions and significantly reduced in the oversized condition (P < 0.01). CONCLUSIONS: Reduced drilling dimensions resulted in increased insertion torque (primary stability). While BIC and BAFO were maximized when drilling the recommended diameter hole, only the oversized hole resulted in evidence of statistically reduced integration.
Assuntos
Implantação Dentária Endóssea/métodos , Implantes Dentários , Torque , Animais , Remodelação Óssea , Cães , Modelos Animais , CicatrizaçãoRESUMO
Endosteal dental implants have been utilized as anchors for dental and orthopedic rehabilitations for decades with one of the highest treatment success rates in medicine. Such success is due to the phenomenon of osseointegration where after the implant surgical placement, bone healing results into an intimate contact between bone and implant surface. While osseointegration is an established phenomenon, the route which osseointegration occurs around endosteal implants is related to various implant design factors including surgical instrumentation and implant macro, micro, and nanometer scale geometry. In an implant system where void spaces (healing chambers) are present between the implant and bone immediately after placement, its inherent bone healing pathway results in unique opportunities to accelerate the osseointegration phenomenon at the short-term and its maintenance on the long-term through a haversian-like bone morphology and mechanical properties.
Assuntos
Implantação Dentária Endóssea/métodos , Implantes Dentários , Osseointegração/fisiologia , Cicatrização/fisiologia , Animais , Remodelação Óssea/fisiologia , Materiais Revestidos Biocompatíveis/química , Materiais Dentários/química , Planejamento de Prótese Dentária , Módulo de Elasticidade/fisiologia , Humanos , Osteogênese/fisiologia , Propriedades de Superfície , Fatores de TempoRESUMO
PURPOSE: The aim of the review was to compare the long-term clinical success of minimally and moderately rough dental implants in terms of differences in marginal bone loss and survival. MATERIALS AND METHODS: The pertinent literature was searched by using the PubMed database and requesting major manufacturers to provide reports of their commercially available dental implant systems. Clinical reports meeting the following criteria were reviewed: results of at least 5 years of follow-up, availability of baseline and follow-up radiographs including intraoral radiographs, and availability of marginal bone loss measurements from the baseline to the end of the follow-up period (5 years or more). All the recorded data were analyzed statistically. RESULTS: Seventy-one of 1202 articles met the inclusion criteria. Maxillary moderately rough implants were found to have significantly higher long-term survival rates than maxillary minimally rough implants; no such difference was noticed in the mandible. Significant marginal bone loss occurred around all the implants in the first year but stabilized thereafter, indicating the absence of progressive bone loss. CONCLUSION: The dental implant systems commercially available today have good long-term clinical success in terms of survival and marginal bone loss.
Assuntos
Implantes Dentários , Perda do Osso Alveolar , Implantação Dentária Endóssea/efeitos adversos , Falha de Restauração Dentária , Seguimentos , Humanos , Fatores de Tempo , Resultado do TratamentoRESUMO
PURPOSE: The aim of this study was to report the outcomes of a treatment option of immediate loading with intraoral welding on only 4 implants for the restoration of patients with maxillary edentulism. MATERIALS AND METHODS: Seventeen consecutive patients were rehabilitated with 2 parallel and 2 tilted implants in the maxilla. Immediately after implant placement, angulated abutments were screwed on the implants to create better parallelism among the implants; thereafter, a titanium bar was intraorally welded to the welding pins to create a superstructure that rigidly splinted the implants. A fixed full-arch durable prosthesis was delivered on the same day of the surgery. The patients were followed for 26.5 months on average. RESULTS: During the follow-up time, 2 implants were lost giving an implant survival rate of 97%. Nonetheless, all the prostheses remained in function and the prosthetic success was 100%. CONCLUSIONS: The rehabilitation of the edentulous maxilla with an immediately loaded full-arch prosthesis, obtained through intraoral welding on only 4 implants, is a functionally and esthetically successful treatment.