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BACKGROUND: For over three decades, digital technologies have been used in Implant Dentistry, beginning with the introduction of planning software for Static Computer-Assisted Implant Surgery (S-CAIS). During this time, this field has witnessed the emergence of diverse methodologies and a proliferation of technological advancements. Today, S-CAIS is a widely adopted procedure for the placement of dental implants in both partially and fully edentulous patients, with Dynamic Computer-Assisted Surgery (D-CAIS) and Robotic-Assisted Implant Surgery (RAIS) rapidly gaining attention among dental professionals. The continuous advancements in this arena are not merely indicative of technological progress; they represent a steadfast dedication to refining precision, enhancing efficiency, and fostering innovation with the goal of optimizing patient outcomes in dental implantology. AIMS: The purpose of the following review is to meticulously examine the spectrum of digital technologies available and to describe their protocols, advantages, and shortcomings as well as to evaluate their accuracy in implant surgery in patients with complete edentulism. MATERIALS AND METHODS: A scoping review was performed following the Joanna Briggs Institute (JBI) protocols, leveraging the population, concept, and context (PCC) framework to construct the research question and determine the inclusion and exclusion criteria. RESULTS: Two hundred and sixty-seven records were identified for screening. After applying all the screening criteria, 41 articles were included for review and qualitative data analysis. DISCUSSION: S-CAIS, D-CAIS, and RAIS were identified as the main technologies for computer assisted implant surgery. Their applications, characteristics, protocols and levels of accuracy were compared and described. CONCLUSION: Taking into consideration the limitations of this study, S-CAIS appears to be the most applied and validated technology in implant surgery for fully edentulous patients followed by D-CAIS and RAIS being these last two promising initiatives in the field. Despite having similar levels of accuracy, the overall comparison showed a slightly higher values in RAIS followed by D-CAIS and S-CAIS.
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Implantação Dentária Endóssea , Boca Edêntula , Cirurgia Assistida por Computador , Humanos , Cirurgia Assistida por Computador/métodos , Boca Edêntula/cirurgia , Implantação Dentária Endóssea/métodos , Tecnologia Digital , Procedimentos Cirúrgicos Robóticos/métodos , Implantes DentáriosRESUMO
OBJECTIVE: This in-vitro study assessed the influence of two intraoral scanning (IOS) protocols on the accuracy (trueness and precision) of digital scans performed in edentulous arches. METHODS: Twenty-two abutment-level master casts of edentulous arches with at least four implants were scanned repeatedly five times, each with two different scanning protocols. Protocol A (IOS-A) consisted of scanning the edentulous arch before inserting the implant scan bodies, followed by their insertion and its subsequent digital acquisition. Protocol B (IOS-B) consisted of scanning the edentulous arch with the scan bodies inserted from the outset. A reference scan from each edentulous cast was obtained using a laboratory scanner. Trueness and precision were calculated using the spatial fit analysis, cross-arch distance, and virtual Sheffield test. Statistical analysis was performed using generalized estimating equations (GEEs). Statistical significance was set at α = .05. RESULTS: In the spatial fit test, the precision of average 3D distances was 45 µm (±23 µm) with protocol IOS-A and 25 µm (±10 µm) for IOS-B (p < .001), and the trueness of average 3D distances was 44 µm (±24 µm) with protocol IOS-A and 24 µm (±7 µm) for IOS-B (p < .001). Cross-arch distance precision was 59 µm (±53 µm) for IOS-A and 41 µm (±43 µm) for IOS-B (p = .0035), and trueness was 64 µm (±47 µm) for IOS-A and 50 µm (±40 µm) for IOS-B (p = .0021). Virtual Sheffield precision was 286 µm (±198 µm) for IOS-A and 146 µm (±92 µm) for IOS-B (p < .001), and trueness was 228 µm (±171 µm) for IOS-A and 139 µm (±92 µm) for IOS-B (p < .001). CONCLUSIONS: The IOS-B protocol demonstrated significantly superior accuracy. Placement of scan bodies before scanning the edentulous arch is recommended to improve the accuracy of complete-arch intraoral scanning.
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Imageamento Tridimensional , Humanos , Técnicas In Vitro , Imageamento Tridimensional/métodos , Implantes Dentários , Desenho Assistido por Computador , Arcada Edêntula/diagnóstico por imagem , Modelos Dentários , Arco Dental/diagnóstico por imagem , Arco Dental/anatomia & histologiaRESUMO
OBJECTIVE: To provide technical and clinical recommendations for implementing a digital workflow in Static Computer-Aided Implant Surgery in the anterior maxilla. CLINICAL CONSIDERATIONS: An optimal 3D implant position is crucial for achieving satisfying results in implant rehabilitation in the esthetic area. Due to its complexity, implant placement in the esthetic zone should be executed with precision and predictability. Static Computer-Aided Implant Surgery requires thorough planning and detailed attention to every step of the digital workflow protocol. CONCLUSIONS: Implant positioning in the esthetic zone using Static Computer-Aided Implant Surgery is a technique-sensitive procedure that requires precise execution of each step. This approach ensures accurate prosthetically driven 3D implant placement and prevents potential errors that could lead to inaccurate positioning. CLINICAL SIGNIFICANCE: The proper implementation of Static Computer-Aided Implant Surgery may increase the level of agreement between the planned and definitive implant 3D positions in the esthetic zone, thus enhancing the esthetic outcomes of implant rehabilitation.
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Implantes Dentários , Cirurgia Assistida por Computador , Estética Dentária , Implantação Dentária Endóssea/métodos , Cirurgia Assistida por Computador/métodos , Maxila/cirurgia , Computadores , Desenho Assistido por Computador , Tomografia Computadorizada de Feixe CônicoRESUMO
OBJECTIVE: This study aims to report the implant survival rate of dental implants of partially dentate patients in the anterior mandible and the potential risk indicators for implant failure. MATERIALS AND METHODS: Patients with implant-supported restorations of single or multiple teeth in the anterior mandible restored with fixed partial implant-supported restorations were evaluated. Patient demographic data, implant placement timing, and loading protocol, biological and/or technical complications at the time of the last clinical and radiographic follow-up visit were registered. Survival rate, success rate, and potential risk indicators for implant failure were calculated. RESULTS: A total of 108 patients and 186 implants with a mean follow-up period of 5.48 years (0.1-11.34 years) were included. The 11.3-year cumulative survival rate was 90.9%. Immediate implant placement (OR = 2.75) (p = .08) and immediate implant loading (OR = 8.8) (p = .02*) indicated a higher risk of failure than late implant placement or loading. When combining both categories (type 1A), an OR = 10.59 (p = .04*) for implant failure was found compared to category 4C. Implants placed following static-computer-assisted implant surgery (S-CAIS) showed less risk of failure compared to freehand implant placement (OR = 0.18; 95% CI: 0.02-1.37) (p = .09). CONCLUSIONS: The survival rate of implants placed in the anterior mandible was considerably low (90.9%). S-CAIS, late placement, and conventional loading are protective factor against implant failure in the anterior mandible.
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Implantes Dentários , Carga Imediata em Implante Dentário , Humanos , Implantação Dentária Endóssea/métodos , Estudos Retrospectivos , Falha de Restauração Dentária , Prótese Dentária Fixada por Implante , Planejamento de Prótese Dentária , Carga Imediata em Implante Dentário/métodos , Mandíbula/cirurgia , SeguimentosRESUMO
OBJECTIVES: The aim of this study was to review available evidence for Type 1A (immediate implant placement and immediate loading) of single tooth replacement in the maxillary esthetic zone. MATERIALS AND METHODS: An electronic search was conducted utilizing the databases of MEDLINE, Embase, and Cochrane to identify publications reporting on the outcomes of Type 1A for single tooth replacement in the maxillary esthetic zone. The success and survival rates of the included articles were reported, which were further categorized according to the clinical criteria reported in Type 1A. Mean survival rates were univariately compared between risk groups and additionally between studies published before and since 2012 using bias-corrected and study size-weighed bootstrap tests. A study time-correcting meta-analysis was then performed to obtain an overall effect for the study pool. RESULTS: A total of 3118 publications were identified in the search, with a total of 68 articles included. A mean number of implants per study were 37.2 and mean follow-up was 2.8 years. All the included studies utilizing Type 1A report highly selective inclusion and exclusion criteria. Univariate risk group comparison determined that studies before 2012 report a significantly lower mean survival rate (difference of -1.9 percentage points [PP], 95% CI: [-0.3, -4.0], p = .02), facial gap dimension had an impact on survival rates (+3.1 PP [0.2, 5.3] for width >2 mm, p = .04), as well as presence of endodontic infection (+2.6 PP [0.9, 5.1], p = .004). CONCLUSIONS: Type 1A has a high survival rate in studies reporting strict patient and site selection criteria. Further research is required to assess esthetic and functional success with Type 1A treatments.
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Implantes Dentários , Humanos , Seleção de Pacientes , Estética Dentária , Bases de Dados FactuaisRESUMO
OBJECTIVES: The aim of this study was to assess the following PIO question: In adult patients treated with an indication for single tooth extraction in the maxillary esthetic zone (15-25), what is the influence of an immediate implant placement and immediate loading protocol on the clinical performance (primary aim) and esthetic outcomes (secondary aim) focusing on investigations published after 2010. MATERIAL AND METHODS: An electronic search in Medline (PubMed), the Cochrane Central Register of Controlled Trials, and EMBASE databases up to April 2022 was performed to identify clinical studies investigating the outcome of single implants subjected to immediate placement with immediate restoration/loading (Type 1A). RESULTS: Sixty-three studies (10 randomized controlled trials, 28 prospective and 25 retrospective cohort studies) were included with a follow-up ranging from 12 to 96 months. One thousand nine hundred sixty-one implants reported survival rates of 99.2 (98.6-99.5) % at 1 year, 97.5 (95.9-98.4) % after 3 years, and 95.8 (93.3-97.4) % after 5 years; 1064 immediately loaded restorations presented survival rates of 98.9 (97.8-99.5) % after 1 year, 96.8 (93.6-98.4) % after 2 years, and 94.8 (89.6-97.4) % after 5 years. Comparing baseline to 12-month data using the Hedges' g effect size (95% CI), papilla height presented an overall effect size of -0.71 (-1.25, -0.1) mm, midfacial recession change of -0.15 (-0.66, 0.36) mm, and a 0.82 (0.37, 1.28) gain in PES. CONCLUSIONS: Immediate implant placement and immediate loading can be considered a predictable and safe treatment option for single maxillary anterior restorations with adequate survival rates and favorable esthetics outcomes for up to 5 years.
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Implantes Dentários , Adulto , Humanos , Estudos Prospectivos , Estudos Retrospectivos , Estética Dentária , Bases de Dados FactuaisRESUMO
OBJECTIVES: Working Group 5 was convened to discuss and find consensus on the topics of implant placement and loading protocols associated with single missing teeth in the anterior maxilla (aesthetic zone). Consensus statements, clinical recommendations, patient perspectives and future research suggestions were developed and presented to the plenary for discussion and approval. MATERIALS AND METHODS: Two systematic reviews were developed and submitted prior to the conference. The group considered in detail the systematic reviews and developed statements, clinical recommendations, patient perspectives and future research suggestions based on the findings of the reviews and experience of group members. Definitive versions were developed after presentation to and discussion by the plenary. RESULTS: Five consensus statements were developed and approved from each systematic review. Twelve clinical recommendations were developed by the group based on both reviews and experience. Three patient perspectives were developed, and five suggestions made for future research. CONCLUSIONS: Based on the findings of the systematic reviews and experience of group members, the Type 1A protocol (immediate placement and immediate loading), when utilized in the anterior maxilla under favorable conditions, is considered predictable and is associated with high survival rates. The procedure is considered clinically viable and is associated with aesthetic outcomes, although surgical, technical, and biological complications can occur.
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Implantes Dentários , Perda de Dente , Humanos , Consenso , Guias de Prática Clínica como Assunto , Revisões Sistemáticas como AssuntoRESUMO
BACKGROUND: Several studies reported cognitive reserve (CR) as an important factor in promoting healthy aging within a non-clinical aging population. AIMS: The main goal of the present study is to investigate the link between higher levels of CR and more effective emotion regulation. In more detail, we examine the association between a number of CR proxies and the habitual use of two emotion regulation strategies, cognitive reappraisal and emotional suppression. METHODS: Three hundred and ten older adults aged between 60 and 75 (mean = 64.45, SD = 4.37; 69.4% female) joined this cross-sectional study by filling out self-report measures of CR and emotion regulation.² RESULTS: Reappraisal and suppression use were correlated. Practicing different leisure activities constantly over many years, being more original and having a higher education promoted more frequent use of cognitive reappraisal. These CR proxies were also significantly related to suppression use, even though the percentage of variance explained was lower. DISCUSSION AND CONCLUSIONS: Exploring the role played by the cognitive reserve on different emotion regulation techniques can be useful in understanding which variables predict the use of antecedent-focused (reappraisal) or response-focused (suppression) emotion regulation strategies in aging individuals.
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Reserva Cognitiva , Regulação Emocional , Humanos , Feminino , Idoso , Masculino , Reserva Cognitiva/fisiologia , Estudos Transversais , Emoções/fisiologia , Envelhecimento/psicologiaRESUMO
The duration of interaction events in a society is a fundamental measure of its collective nature and potentially reflects variability in individual behavior. Here we performed a high-throughput measurement of trophallaxis and face-to-face event durations experienced by a colony of honeybees over their entire lifetimes. The interaction time distribution is heavy-tailed, as previously reported for human face-to-face interactions. We developed a theory of pair interactions that takes into account individual variability and predicts the scaling behavior for both bee and extant human datasets. The individual variability of worker honeybees was nonzero but less than that of humans, possibly reflecting their greater genetic relatedness. Our work shows how individual differences can lead to universal patterns of behavior that transcend species and specific mechanisms for social interactions.
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Comportamento Animal/fisiologia , Variação Biológica Individual , Modelos Biológicos , Comportamento Social , Interação Social , Animais , Abelhas/fisiologia , Conjuntos de Dados como Assunto , Ensaios de Triagem em Larga Escala , Humanos , Individualidade , Fatores de TempoRESUMO
Anthropogenic changes create evolutionarily novel environments that present opportunities for emerging diseases, potentially changing the balance between host and pathogen. Honey bees provide essential pollination services, but intensification and globalization of honey bee management has coincided with increased pathogen pressure, primarily due to a parasitic mite/virus complex. Here, we investigated how honey bee individual and group phenotypes are altered by a virus of concern, Israeli acute paralysis virus (IAPV). Using automated and manual behavioral monitoring of IAPV-inoculated individuals, we find evidence for pathogen manipulation of worker behavior by IAPV, and reveal that this effect depends on social context; that is, within versus between colony interactions. Experimental inoculation reduced social contacts between honey bee colony members, suggesting an adaptive host social immune response to diminish transmission. Parallel analyses with double-stranded RNA (dsRNA)-immunostimulated bees revealed these behaviors are part of a generalized social immune defensive response. Conversely, inoculated bees presented to groups of bees from other colonies experienced reduced aggression compared with dsRNA-immunostimulated bees, facilitating entry into susceptible colonies. This reduction was associated with a shift in cuticular hydrocarbons, the chemical signatures used by bees to discriminate colony members from intruders. These responses were specific to IAPV infection, suggestive of pathogen manipulation of the host. Emerging bee pathogens may thus shape host phenotypes to increase transmission, a strategy especially well-suited to the unnaturally high colony densities of modern apiculture. These findings demonstrate how anthropogenic changes could affect arms races between human-managed hosts and their pathogens to potentially affect global food security.
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Abelhas/virologia , Dicistroviridae/metabolismo , Interações Hospedeiro-Patógeno/fisiologia , Animais , Criação de Abelhas/métodos , Abelhas/genética , Comportamento Animal , Colapso da Colônia/epidemiologia , Vírus de DNA/genética , Vírus de DNA/metabolismo , Dicistroviridae/genética , Dicistroviridae/patogenicidade , Transmissão de Doença Infecciosa/veterinária , Ácaros/genética , Polinização , RNA de Cadeia Dupla , Comportamento Social , VirulênciaRESUMO
OBJECTIVE: To describe a strategy using digital technologies for improving the diagnosis, treatment planning, and surgical execution of patients with excessive gingival display (EGD) due to altered passive eruption (APE). CLINICAL CONSIDERATIONS: An important component for successful patient's management is to fulfill their esthetic expectations whilst delivering predictable and long-term therapeutic outcomes. To achieve this goal in patients with excessive gingival display due to altered passive eruption, it is essential to perform an accurate diagnosis and to communicate to the patient the expected customized results using digital technologies. Computer-aided designed and manufactured multifunctional anatomical prototypes (MAPs) may contribute to these purposes. Additionally, they can guide the surgical crown lengthening procedure or serve as a reference during the surgical guide fabrication providing information of the required anatomical landmarks. CONCLUSIONS: This novel strategy protocol for diagnosis, communication, and treatment management of patients with excessive gingival display follows functional and biological principles within the frame of a digital workflow, which improves the diagnostic capabilities, enhances communication, and guides the surgical treatment as shown in the 12 months follow-up of the reported case. CLINICAL SIGNIFICANCE: Developing a virtual patient by combining multiple digital data sets including cone-beam computed tomography (CBCT), intra-oral scans and digital photography, supports the clinician and the patient to achieve a comprehensive diagnosis and to better communicate the expected results to the patient. Furthermore, this digital treatment exercise based on anatomical and biological principles will facilitate the surgical precision and the achievement of successful outcomes, thus fulfilling the patient needs and expectations.
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Estética Dentária , Dente , Humanos , Gengiva , Coroa do Dente , GengivectomiaRESUMO
A method is described for the verification and correction of a digital scan of a complete arch implant-supported prosthesis for a completely edentulous patient. The technique provides an efficient way to integrate a highly accurate and precise scan of an implant index cast with a digital intraoral implant scan by using a computer-aided design and computer-aided manufacturing (CAD-CAM) software program. This method allows dental professionals to validate and, if necessary, correct the implant positions in the scan without the need for a conventional impression.
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Implantes Dentários , Boca Edêntula , Humanos , Materiais para Moldagem Odontológica , Técnica de Moldagem Odontológica , Prótese Dentária Fixada por Implante , Desenho Assistido por ComputadorRESUMO
Removal of cement-retained complete arch implant-supported zirconia restorations can be challenging. A predictable and minimally invasive technique combining cone beam computed tomography (CBCT) and intraoral scans with a virtual implant planning software program is described to identify the location of the screw access channels during the retrieval, thus minimizing damage to the existing restoration and allowing reuse.
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Adverse social experience affects social structure by modifying the behavior of individuals, but the relationship between an individual's behavioral state and its response to adversity is poorly understood. We leveraged naturally occurring division of labor in honey bees and studied the biological embedding of environmental threat using laboratory assays and automated behavioral tracking of whole colonies. Guard bees showed low intrinsic levels of sociability compared with foragers and nurse bees, but large increases in sociability following exposure to a threat. Threat experience also modified the expression of caregiving-related genes in a brain region called the mushroom bodies. These results demonstrate that the biological embedding of environmental experience depends on an individual's societal role and, in turn, affects its future sociability.
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Encéfalo , Corpos Pedunculados , Animais , Abelhas/genética , Encéfalo/fisiologia , Expressão Gênica , Corpos Pedunculados/metabolismo , Rede SocialRESUMO
OBJECTIVES: Registration of intra-oral surface scans to cone beam computer tomography (CBCT) is critical in the digital workflow for static computer-aided implant surgery (sCAIS). This study aimed to assess the impact of CBCT field of view (FoV) on the precision of digital intra-oral scan registration. MATERIALS AND METHODS: Cone beam computer tomography data and intra-oral scans from 20 patients were included. Small FoV CBCT's were created by digitally segmenting a large FoV into three sextants. Virtual implant planning was performed. Digital intra-oral scans were repeatedly registered onto their corresponding large and small FoV CBCT datasets. The distances and angulations between the matching implant positions of each repeated registration were used to determine the precision of the registration process. Wilcoxon Signed Rank Paired Tests were used to compare the differences between large FoV and small FoV. The threshold for statistical significance was set at p = .05. RESULTS: Differences in 3D implant position based on the registration precision between small FoV and large FoV present at both the implant entry point (0.37 ± 0.25 mm vs 0.35 ± 0.23 mm, p = .482) and implant tip (0.49 ± 0.34 mm vs 0.37 ± 0.24 mm, p < .001). Differences in overall angular precision were observed between small FOV and large FoV (1.43 ± 1.36° vs 0.51 ± 0.38°, p < .001). CONCLUSION: CBCT with a small FoV is accompanied by greater precision errors in intra-oral scan registration. However, when sufficient well-distributed teeth are visible in small FoV CBCT, the precision of digital intra-oral scan registration appears to be within clinically acceptable limits for sCAIS.
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Tomografia Computadorizada de Feixe Cônico , Implantação Dentária , Boca , Cirurgia Assistida por Computador , Humanos , Implantação Dentária/métodos , Boca/diagnóstico por imagemRESUMO
This clinical report describes a completely digital workflow for the rehabilitation of the maxillary and mandibular arches with implant-supported fixed interim prostheses. Computer-assisted implant planning was used to fabricate a multifunctional surgical template for the guided placement of transitional and endosteal dental implants. Advantages of this technique include the integration of a completely digital workflow into the production of a virtual diagnostic tooth arrangement for edentulous patients, the planning of implant placement as per a restorative-driven approach, and the delivery of implant-supported fixed interim prostheses.
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Implantes Dentários , Prótese Dentária Fixada por Implante , Desenho Assistido por Computador , Implantação Dentária Endóssea , Planejamento de Prótese Dentária , Dentição , Humanos , Fluxo de TrabalhoRESUMO
A method for the digital articulation of complete arch digital implant scans using the implant abutment prosthetic interfaces is described. This technique provides an effective and efficient method for articulating digital scans without the need for matching soft tissue references or fiduciary markers. This allows for a streamlined workflow with fewer intraoral scans and can provide a precise replication of the intaglio surface and emergence profile of an existing restoration.
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Static computer assisted implant surgery (s-CAIS) is an integral part of the digital workflow in implant dentistry and provides the link between the virtual planning environment and surgical field. The accuracy of s-CAIS is influenced by many cumulative factors including the fit of the template which is related to the manufacturing process. This critical review provides an overview of the current research on additively manufactured surgical implant guides.
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Implantes Dentários , Cirurgia Assistida por Computador , Desenho Assistido por Computador , Implantação Dentária EndósseaRESUMO
OBJECTIVES: This study aimed to determine whether distally angulating an implant is a successful strategy to avoid the maxillary sinus and the need for bone augmentation, while increasing the anterior-posterior (A-P) implant distribution in the edentulous maxilla. MATERIALS AND METHODS: In 115 patients with edentulous maxillae, virtual implant planning was performed utilizing cone-beam computer tomographs. Axial (8 mm length) and tilted (12 mm length) dental implants with 30-degree and 45-degree angulation were virtually positioned to avoid entering the maxillary sinus, while maximizing A-P distribution. Measurements were made between the tilted and axial implants to assess the change in A-P distribution of implants at the implant and abutment levels. RESULTS: Forty-seven sites (20.4%) were not able to have either treatment modality with insufficient bone for implant placement. Axial implants were placed more distally than 45-degree and 30-degree tilted implants in 24% and 42% of sites, respectively. The average change in A-P spread measured at the implant level, for 30- and 45-degree tilted implants was -0.25 mm (95% CI -0.76, 0.26) and 1.9 mm (95% CI 1.4, 2.3), respectively. When measured from the center of each multi-unit abutment the average increase in A-P distances for tilted implants appears larger in the 30-degree and 45-degree groups by 0.97 mm and 1.74 mm, respectively compared to measurements at the implant level. CONCLUSIONS: Angulating 12 mm implants provides a limited increase in A-P distribution of implants in edentulous rehabilitation in most situations. In certain patients, the use of 8mm axial implants may provide a greater A-P spread.
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Implantes Dentários , Arcada Edêntula , Tomografia Computadorizada de Feixe Cônico Espiral , Implantação Dentária Endóssea , Planejamento de Prótese Dentária , Prótese Dentária Fixada por Implante , Seguimentos , Humanos , Arcada Edêntula/diagnóstico por imagem , Arcada Edêntula/cirurgia , Maxila/diagnóstico por imagem , Maxila/cirurgiaRESUMO
PURPOSE: The ability to maintain an absolute, submaximal torque level during fatiguing contractions is controlled, in part, by the recruitment of larger motor units. These motor units are commonly identified based on greater action potential peak-to-peak amplitude values. It is unclear, however, if motor unit action potential (MUAP) amplitude values during low torque, fatiguing contractions reach similar levels as those observed during non-fatigued, high torque contractions. To establish a clearer understanding of motor unit control during fatigue, we compared MUAP amplitude during 50 and 80% maximum voluntary contraction (MVC) torque contractions and at the beginning, middle, and end of a 30% MVC fatigue protocol. METHODS: Eleven untrained men (mean age = 24 years) performed isometric contractions at 50 and 80% MVC, followed by repeated contractions at 30% MVC. Surface electromyographic (EMG) signals were detected from the vastus lateralis and decomposed to quantify the peak-to-peak amplitude of individual MUAPs. A two-level multilevel model was estimated, allowing examination of simultaneous measures of MUAP amplitude within participants and controlling for the dependence between measures within participants. RESULTS: Results from the multilevel analyses suggested that there were not statistically significant differences in MUAP amplitude between 80% MVC and end fatigue. Separate repeated-measures analyses of variance indicated that there were not statistically significant mean differences in greatest MUAP or surface EMG amplitude between 80% MVC and end fatigue. CONCLUSIONS: MUAP and surface EMG amplitude values during a 30% MVC fatiguing protocol appear to be comparable to those observed during a non-fatigued 80% MVC condition.