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Made available in DSpace on 2021-06-25T10:45:02Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-05-01 The aim of this systematic review and meta-analysis was to evaluate studies comparing implant survival rates, marginal bone loss (MBL), and mechanical and biological complication rates between narrow-diameter implants (NDIs) and regular-diameter implants (RDIs) used for oral rehabilitation in the anterior region. The review was conducted according to the PRISMA checklist. Two independent reviewers performed a comprehensive search of the PubMed/MEDLINE, Embase, Scopus, and Cochrane Library databases for studies published until May 2020. A total of 843 implants (484 NDIs and 359 RDIs) were included. No significant difference in implant survival rate (risk difference (RD) 0.01, 95% confidence interval (CI) −0.01 to 0.03; P = 0.34), MBL (standardised mean difference −0.51 mm, 95% CI −1.29 to 0.26 mm; P = 0.19), mechanical complications (RD 0.01, 95% CI −0.02 to 0.04; P = 0.40), or biological complications (RD 0.01, 95% CI −0.09 to 0.11; P = 0.85) was found between the implant groups. Within the limitations of this study, it is concluded that NDIs are an effective alternative to RDIs due to similar survival rates, MBL, and mechanical and biological complication rates. However, future studies are highly encouraged due to the small number of interventional studies on this topic. Department of Dental Materials and Prosthodontics Aracatuba Dental School UNESP – Universidade Estadual Paulista Campus of Aracatuba Department of Dentistry Federal University of Juiz de Fora (UFJF) Campus Governador Valadares Governador Valadares Department of Prosthodontics Presidente Prudente Dental School University of the West of São Paulo (UNOESTE) Department of Dental Materials and Prosthodontics Aracatuba Dental School UNESP – Universidade Estadual Paulista Campus of Aracatuba

Made available in DSpace on 2018-12-11T17:21:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-01-01 Statement of problem: The decision to splint or to restore independently generally occurs during the planning stage, when the advantages and disadvantages of each clinical situation are considered based on the proposed treatment. However, clinical evidence to help clinicians make this decision is lacking. Purpose: The purpose of this systematic review and meta-analysis was to assess the marginal bone loss, implant survival rate, and prosthetic complications of splinted and nonsplinted implant restorations. Material and methods: This study was designed according to the Cochrane criteria for elaborating a systematic review and meta-analysis and adopted the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Also, this review was registered at the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42017080162). An electronic search in the PubMed/MEDLINE, Cochrane Library, and Scopus databases was conducted up to November 2017. A specific clinical question was structured according to the population, intervention, comparison, outcome (PICO) approach. The addressed focused question was “Should the restoration of adjacent implants be splinted or nonsplinted?” The meta-analysis was based on the Mantel-Haenszel and inverse variance methods to assess the marginal bone loss, implant survival, and prosthetic complications of splinted and nonsplinted implant restorations. Results: Nineteen studies were selected for qualitative and quantitative analyses. A total of 4215 implants were placed in 2185 patients (splinted, 2768; nonsplinted, 1447); the mean follow-up was 87.8 months (range=12-264 months). Quantitative analysis found no significant differences between splinted and nonsplinted restorations for marginal bone loss. The assessed studies reported that 75 implants failed (3.4%), of which 24 were splinted (99.1% of survival rate) and 51 were nonsplinted (96.5% of survival rate). Quantitative analysis of all studies showed statistically significant higher survival rates for splinted restorations than for nonsplinted restorations. Ceramic chipping, screw loosening, abutment screw breakage, and soft tissue inflammation were reported in the selected studies. The quantitative analysis found no statistically significant difference in the prosthetic complications of splinted and nonsplinted restorations. Conclusions: Within the limitations of this systematic review and meta-analysis, it was concluded that there was no difference in the marginal bone loss and prosthetic complications of splinted and nonsplinted implant restorations; this is especially true for restorations in the posterior region. However, splinted restorations were associated with decreased implant failure. Associate Professor Department of Prosthodontics Presidente Prudente Dental School University of Western São Paulo (UNOESTE) Adjunct Professor Department of Dental Materials and Prosthodontics Araçatuba Dental School São Paulo State University (UNESP) Doctoral student Department of Dental Materials and Prosthodontics Araçatuba Dental School São Paulo State University (UNESP) Graduate student Department of Dental Materials and Prosthodontics Araçatuba Dental School São Paulo State University (UNESP) Full Professor Department of Dental Materials and Prosthodontics Araçatuba Dental School (UNESP) Universidade Estadual Paulista Adjunct Professor Department of Dental Materials and Prosthodontics Araçatuba Dental School São Paulo State University (UNESP) Doctoral student Department of Dental Materials and Prosthodontics Araçatuba Dental School São Paulo State University (UNESP) Graduate student Department of Dental Materials and Prosthodontics Araçatuba Dental School São Paulo State University (UNESP) Full Professor Department of Dental Materials and Prosthodontics Araçatuba Dental School (UNESP) Universidade Estadual Paulista

This is an in silico study aimed to evaluate the biomechanical influence of different implant-abutment interfaces (external hexagon and Morse taper implants), retention systems (cement and screw retained), and restorative crowns (metal-ceramic and monolithic) using 3-dimensional finite element analysis (3D-FEA). Eight 3D models were simulated for the maxillary first molar area using InVesalius, Rhinoceros, and SolidWorks and processed using Femap and NEi Nastran software. Axial and oblique forces of 200 and 100 N, respectively, were applied on the occlusal surface of the prostheses. Microstrain and von Mises stress maps were used to evaluate the deformation (cortical bone tissue) and stress (implants/fixation screws/crowns), respectively, for each model. For both loadings, Morse taper implants had lower microstrain values than the external hexagon implants. The retention system did not affect microstrain on the cortical bone tissue under both loadings. However, the cemented prosthesis displayed higher stress with the fixation screw than the external hexagon implants. No difference was observed between the metal-ceramic and zirconia monolithic crowns in terms of microstrain and stress distribution on the cortical bone, implants, or components. Morse taper implants can be considered as a good alternative for dental implant rehabilitation because they demonstrated better biomechanical behavior for the bone and fixation screw as compared to external hexagon implants. Cement-retained prosthesis increased the stress on the fixation screw of the external hexagon implants, thereby increasing the risk of screw loosening/fracture in the posterior maxillary area. The use of metal-ceramic or monolithic crowns did not affect the biomechanical behavior of the evaluated structures.

The aim in the present study was to analyze the stress in the external hexagon implant (EH) in a situation of parafunction on three-unit implant-supported prostheses with and without the use of the acrylic occlusal device (AOD) using three-dimensional (3D) finite element analysis (FEA). Eight 3D models referring to the posterior maxilla with three EH supporting single and or splinted screwed metal-ceramic restoration and use of the AOD. AOD was modeled with a thickness of 2 mm. EHs were analyzed using von Mises criteria in the ANSYS 19.2 program. AOD showed to be effective in reducing stress in the EH. However, the use of the AOD was not effective enough to suggest the non-splinting of EH dental implant. The association of splinting and the use of an AOD in the posterior region of the maxilla may be an effective way to decrease the stress in the EH implant in a situation of parafunction. El objetivo em el presente estudio fue analizar la tensión en el implante de hexágono externo (HE) en una situación de parafunción en prótesis implantosoportadas de tres unidades con y sin el uso del dispositivo oclusal acrílico (DOA) utilizando tres dimensiones (3D) análisis de elementos finitos. Ocho modelos 3D referidos al maxilar posterior con tres HE que soportan la restauración metalocerámica atornillada y/o ferulizada y el uso del AOD. El DOA se modeló con un espesor de 2 mm. Los HE se analizaron utilizando los criterios de von Mises en el programa ANSYS 19.2. DOA demostró ser eficaz para reducir el estrés en el HE. Sin embargo, el uso del DOA no fue lo suficientemente eficaz como para sugerir la no ferulización del implante dental HE. La asociación de ferulización y el uso de un DOA en la región posterior del maxilar puede ser una forma eficaz de disminuir la tensión en el implante HE en una situación de parafunción. O objetivo no presente estudo foi analisar a tensão no implante de hexágono externo (HE) em situação de parafunção em próteses de três elementos implantossuportadas com e sem o uso do dispositivo oclusal de acrílico (DOA) por meio da análise de elementos finitos (AEF) tridimensional (3D). Oito modelos 3D simulados referentes à região posterior da maxila com três HE suportando próteses metalocerâmica unitária e/ou esplintada parafusada e uso de DOA. O DOA foi modelado com espessura de 2 mm. Os HEs foram analisados usando os critérios de von Mises no programa ANSYS 19.2. O DOA mostrou-se eficaz na redução da tensão no HE. No entanto, o uso do DOA não foi eficaz o suficiente para sugerir a não esplintagem do implante dentário HE. A associação de esplintagem e o uso de DOA na região posterior da maxila pode ser uma forma eficaz de diminuir a tensão no implante de HE em situação de parafunção.

Made available in DSpace on 2021-06-25T10:40:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Statement of problem: A consensus regarding the biomechanical effects of vertical bone loss in normal and osteoporotic bone tissue according to different implant-abutment interfaces is lacking. Purpose: The purpose of this finite element analysis study was to evaluate the effect of vertical bone loss (without bone loss; with 1.5-mm bone loss; with 3-mm bone loss; and with 4.5-mm bone loss) in normal and osteoporotic bone that received a Ø4×10-mm implant with different implant-abutment connections (external connection [external hexagon] and internal connection [Morse taper]) by using 3D finite element analysis. Material and methods: Sixteen 3D models were simulated. Axial and oblique forces of 200 N and 100 N, respectively, were applied on the occlusal surfaces of the prostheses. Maximum principal stress and microstrain were determined from the bone tissue of each model. von Mises stress analysis was used to evaluate the stress distribution in implants and prosthetic components (fixation screws, abutment, and crown). Results: The results showed higher stress concentrations in models with bone loss as increased vertical bone loss contributed to higher stress and microstrain in the bone tissue, regardless of the quality of bone and implant-abutment connection. Osteoporotic bone contributed to increase in microstrain in the trabecular bone. The internal connection showed lower stress than the external connection implants only in models without marginal bone loss. Furthermore, higher stress concentrations were observed in the implants and fixation screws in models with increased bone loss and external connection implants, mainly under oblique loading. Osteoporotic bone did not affect stress distribution in the implants and prosthetic components. Conclusions: Progressive bone loss contributed to higher stress in the bone tissue, implants, and prosthetic components. The osteoporotic bone affects only the microstrain in the trabecular bone, but not the stress in the implants and prosthetic components. The internal connection implants showed lower stress in the cortical bone only in models without bone loss, while external connection implants exhibited higher stress in the implants and screws under oblique loading. Adjunct Professor Division of Prosthodontics Department of Dentistry Federal University of Juiz de Fora (UFJF-GV) Associate Professor Department of Dental Materials and Prosthodontics Araçatuba Dental School Universidade Estadual Paulista (UNESP) Researcher Tridimensional Technology Division Renato Archer's Information Technology Center Department Prosthodontics Presidente Prudente Dental School University of the West of São Paulo (UNOESTE) PhD student Department of Dental Materials and Prosthodontics Araçatuba Dental School Universidade Estadual Paulista (UNESP) Titular Professor Department of Dental Materials and Prosthodontics Araçatuba Dental School Universidade Estadual Paulista (UNESP) Associate Professor Department of Dental Materials and Prosthodontics Araçatuba Dental School Universidade Estadual Paulista (UNESP) PhD student Department of Dental Materials and Prosthodontics Araçatuba Dental School Universidade Estadual Paulista (UNESP) Titular Professor Department of Dental Materials and Prosthodontics Araçatuba Dental School Universidade Estadual Paulista (UNESP) FAPESP: 2009/16164-7 FAPESP: 2015/24442-8 CNPq: 306288/2016-8

Made available in DSpace on 2020-12-12T02:22:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-01-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) The purpose of this systematic review was to compare computer-guided (fully guided) and freehand implant placement surgery in terms of marginal bone loss, complications, and implant survival. This review followed the PRISMA guidelines and was registered in the PROSPERO database (CRD42019135893). Two independent investigators performed the search of the PubMed/MEDLINE, Scopus, and Cochrane Library databases for studies published up to April 2020 and identified 1508 references. After a detailed review, only four studies were considered eligible. These studies involved a total of 154 patients with 597 dental implants and a mean follow-up period of 2.25 years. There was no difference between computer-guided surgery and freehand surgery in terms of the marginal bone loss (mean difference −0.11 mm, 95% confidence interval (CI) −0.27 to 0.04 mm; P = 0.16), mechanical complications (risk ratio (RR) 0.85, 95% CI 0.36–2.04; P = 0.72), biological complications (RR 1.56, 95% CI 0.42–5.74; P = 0.51), and implant survival rate (RR 0.53, 95% CI 0.11–2.43; P = 0.41). This meta-analysis demonstrated that both computer-guided and freehand surgeries yielded similar results for marginal bone loss, mechanical and biological complications, and implant survival rate. Department of Dental Materials and Prosthodontics Araçatuba Dental School UNESP – Universidade Estadual Paulista Araçatuba Department of Dental Materials and Prosthodontics Araçatuba Dental School UNESP – Universidade Estadual Paulista Araçatuba CNPq: 130794/2019-8

No consensus has been reached on the use of dental implants in human immunodeficiency virus (HIV)-positive patients. This systematic review evaluated dental implants in HIV-positive patients in terms of implant survival and success rates, marginal bone loss, and complications. The review was conducted according to the PRISMA checklist. Two independent reviewers performed a comprehensive search of the PubMed/MEDLINE, Scopus, and Cochrane Library databases for studies published until October 2017. Six studies were selected for review. In total, 821 implants were placed: 493 in 169 HIV-positive patients, and 328 in 135 HIV-negative patients. The mean duration of follow-up was 47.9 months. Weighted mean survival rate, success rate, and marginal bone loss values were calculated for the HIV-positive patients. Mean survival and success rates at the patient level (according to the number of patients) were 94.76% and 93.81%, respectively; when calculated at the implant level (according to the number of implants), these rates were 94.53% and 90.37%, respectively. Mean marginal bone loss was 0.83mm at the patient level and 0.99mm at the implant level. Thus, dental implants are suitable for the rehabilitation of HIV-positive patients with controlled risk factors and normal CD4+ cell counts.

Department of Dental Materials and Prosthodontics Aracatuba Dental School UNESP – Universidade Estadual Paulista

This study aimed to evaluate the stress distribution in bone tissue, in Morse tapper implants and components supporting a single crown in the maxillary anterior area, under different bone anchorages (conventional, bicortical and bicortical with nasal floor elevation) and implant lengths (8.5 mm, 10 mm and 11.5 mm) using 3D finite element analyses. Three 3D models including element #11 were simulated using software InVesalius, Rhinoceros 3D and SolidWorks. Bone block models were reconstructed from computed tomography and simulated the placement of one implant of 4 mm of diameter and lengths above mentioned, supporting cemented zirconia crown. The 3D models were processed by the finite element FEMAP and NeiNastran software, using a load of 178N were applied at 0º, 30º and 60º, considering the implant long axis. Results were visualized as the von Mises stress, maximum principal stress and microstrain maps. Bicortical bone anchorages showed lower stress and microstrain bone tissue when compared to conventional bone anchorage. However, no differences were observed between bicortical and nasal floor elevation. Regarding implants and components, the stress distribution was similar between models with little stress relief in the apical region of the implants for implants with conventional anchorage. The conclusion drawn from this study is that non-axial loading showed worse biomechanical behavior for bone tissue and implants/components. The bicortical techniques (bicortical and nasal floor elevation) should be preferred during the implant placement to reduce the stress and microstrain in the bone tissue. Este estudio tuvo como objetivo evaluar la distribución de tensiones en tejido óseo, en implantes Morse y componentes que sostienen una corona en la zona anterior maxilar, bajo diferentes anclajes óseos (convencional, bicortical y bicortical con elevación nasal) y longitudes de implante (8,5mm, 10mm y 11,5mm) utilizando análisis de elementos finitos 3D. Se simularon tres modelos 3D, incluido el elemento 11, utilizando el software InVesalius, Rhinoceros 3D y SolidWorks. Se reconstruyeron modelos de bloques óseos a partir de tomografía computarizada y se simuló la colocación de un implante de 4mm de diámetro y longitudes antes mencionadas, soportando la corona de circonio cementado. Los modelos 3D fueron procesados por el software de elementos finitos FEMAP y NeiNastran, utilizando una carga de 178N se aplicaron a 0º, 30º y 60º, considerando el eje largo del implante. Los resultados se visualizaron como el estrés de von Mises, el estrés principal máximo y microdeformación. Los anclajes óseos bicorticales mostraron menor tensión y microesfuerzo del tejido óseo en comparación con el convencional. No se observaron diferencias entre la elevación bicortical y del piso nasal. En cuanto a implantes y componentes, la distribución de tensiones fue similar entre modelos con escaso alivio de tensiones en la región apical de los implantes con anclaje convencional. llegamos a la conclusión de que es que la carga no axial mostró un peor comportamiento biomecánico para el tejido óseo y los implantes/componentes. Se deben preferir las técnicas bicorticales durante la colocación del implante para reducir la tensión y la microesfuerzo. O objetivo deste estudo foi avaliar a distribuição de estresse em implantes cone morse, no tecido ósseo e em coroas unitárias na região anterior da maxila, em diferentes ancoragens ósseas (convencional, bicortical e bicortical com levantamento de assoalho nasal) utilizando a metodologia de elementos finitos 3D variando o comprimento dos implantes (8.5mm, 10mm, 11,5mm). Três modelos 3D, incluindo o elemento #11, foram simulados usando o software InVesalius, Rhinoceros 3D e SolidWorks. Modelos de blocos ósseos foram reconstruídos a partir da tomografia computadorizada e simularam a instalação de um implante de 4mm de diâmetro e comprimentos acima mencionados, suportando coroa de zircônia cimentada. Os modelos 3D foram processados nos softwares de elementos finitos FEMAP e NeiNastran, utilizando uma carga de 178N foram aplicados a 0º, 30º e 60º, considerando o longo eixo do implante. Os resultados foram visualizados como mapas de tensão de von Mises, a tensão máxima principal e microdeformação. As ancoragens ósseas bicorticais apresentaram menor estresse e microdeformação do tecido ósseo quando comparadas à ancoragem óssea convencional. No entanto, não foram observadas diferenças entre a elevação bicortical e do assoalho nasal. Em relação aos implantes e componentes, a distribuição de tensões foi semelhante entre os modelos com pouco alívio de tensões na região apical dos implantes para ancoragem convencional. Concluímos cargas oblíquas apresentam pior comportamento biomecânico para tecido ósseo e implantes/componentes. As técnicas bicorticais (elevação bicortical e do assoalho nasal) devem ser preferidas durante a instalação do implante para reduzir o estresse e a microdeformação no tecido ósseo.

Statement of problem How the performance of dental implants is related to their occlusogingival placement, crestal or subcrestal, is unclear. Purpose The purpose of this systematic review and meta-analysis was to evaluate marginal bone loss, implant survival rate, and peri-implant soft tissue parameters between implants placed at the crestal and subcrestal bone level. Material and methods Two independent reviewers searched the PubMed/MEDLINE, Embase, and Cochrane Library databases for randomized clinical trials published up to September 2020. The meta-analysis was based on the Mantel-Haenszel and the inverse variance methods (α=.05). Results The search identified 928 references, and 10 studies met the eligibility criteria. A total of 393 participants received 709 implants, 351 at crestal bone levels and 358 at subcrestal bone levels. Meta-analysis indicated that crestal bone level implants showed similar marginal bone loss to that seen with subcrestal bone level implants (mm) (P=.79), independent of the subcrestal level (P=.05) and healing protocol (P=.24). The bone level implant placement did not affect the implant survival rate (P=.76), keratinized tissue (mm) (P=.91), probing depth (mm) (P=.70), or plaque index (%) (P=.92). Conclusions The evidence suggests that both approaches of implant placement are clinically acceptable in terms of peri-implant tissue parameters and implant-supported restoration survival.

Statement of problem A consensus on the clinical performance in dental implants placed with different insertion torques is lacking. Purpose The purpose of this systematic review and meta-analysis was to evaluate the effect of high insertion torque compared with regular or low torques during dental implant placement in terms of implant survival rate and marginal bone loss. Material and methods Two independent reviewers searched electronic databases for studies published until April 2019. The population, intervention, comparison, outcome (PICO) question was “Do patients who receive implants with a high torque (equal or higher than 50 Ncm) show similar implant survival rates and marginal bone loss as compared with those who receive implants with a regular or low torque (less than 50 Ncm)?”. The meta-analysis was based on the Mantel-Haenszel (MH) and the inverse variance (IV) methods (α=.05). Results The search yielded 6 articles, which included 389 patients (mean age: 55.28 years) who had received 651 dental implants (437 with high torque and 214 with low or regular torque). Most studies evaluated delayed loading, except 1 study that evaluated immediate implant loading (n=50 for each group). Low or regular insertion torque had a high failure rate (4.2%) compared with high insertion torque (1.1%), chiefly because of immediate loading. However, the meta-analysis indicated no significant difference between high- and regular- or low-torque implant placement in implant survival rate (P=.52, risk ratio [RR]: 0.51, 95% confidence interval [CI]: 0.06-4.06) and marginal bone loss (P=.30, mean difference [MD]: 0.15, 95% CI: -0.14 to 0.44). Conclusions A high insertion torque during implant placement does not affect implant survival rate or marginal bone loss. However, further research is recommended to reassess this clinical performance.

The objective of the present study was to analyze the stress and microstrain on cortical bone tissue caused by occlusal forces on three-unit implant-supported prostheses placed in the maxillary posterior region through varying configuration factors and implant lengths using 3D finite element analysis. Fifteen three-dimensional models were simulated with the support of the In Vesalius, SolidWorks 2016, and Rhinoceros 4.0 software programs. Each three-dimensional model included a maxillary bone block corresponding to the region from the 1st premolar to the 1st right molar with three EH implants measuring 4.0 mm in diameter, which supported the three-unit metal-ceramic screw-retained prosthesis through varying configuration factors (single-unit and splinted crowns: straight-line and tripod design) and implant lengths (10, 8.5, and 7 mm × Ø4 mm). The FEMAP 11.4.2 program was used to generate the finite element models in the pre- and post-processing phases. Bone tissue was analyzed using Maximum Principal Stress (MPa) and Microstrain (με) maps. The highest stress/microstrain values were observed in oblique loading. In addition, splinting associated with the offset configuration generated improved biomechanical behavior. Furthermore, the association of short implants with longer implants did not exhibit any biomechanical benefits. Moreover, a reduced implant length (i.e., 7 mm) generated unfavorable biomechanical behavior. Splinting was effective in reducing the stress/microstrain on cortical bone tissue, especially when associated with the offset configuration of the implants. Also, an increased implant length decreased the stress/microstrain in the bone tissue, and splinted short implants presented similar biomechanical behavior to short implants associated with longer implants. El objetivo del presente estudio fue analizar la tensión y microdeformación del tejido óseo cortical generada por las fuerzas oclusales sobre las prótesis de tres elementos implantosoportados, variando la unión y longitud de los implantes, instalados en la región posterior del maxilar. Quince modelos tridimensionales se simularon y cada modelo tridimensional consistió en un bloque óseo maxilar referido a la región de la 1ª PM a la 1ª M derecha, presentando tres implantes de hexágono externo (HE) de 4.0 mm de diámetro, soportando una prótesis metalocerámica atornillada, variando el factor unión (coronas unitarias y ferulizadas: rectas y en posición tripoide), longitud con implantes (10 mm, 8,5 mm y 7 mm Ø4 mm). El análisis del tejido óseo se realizó utilizando los mapas de Máxima Máxima Tensión (MPa) y Microdeformación (µε). Los mayores valores de la tensión/microdeformación se observaron en la carga oblicua. El entablillado asociado al posicionamiento del trípode generó un mejor comportamiento biomecánico. La asociación de implantes cortos con implantes más largos no ha demostrado un beneficio biomecánico. La reducción de la longitud del implante (7 mm) generó un comportamiento biomecánico desfavorable. La ferulización fue eficaz para reducir la tensión/microdeformación del tejido óseo cortical, especialmente cuando se asocia con el posicionamiento trípode de los implantes. El aumento de la longitud del implante disminuyó la tensión/microdeformación en el tejido óseo. Los implantes ferulizados cortos mostraron un comportamiento biomecánico similar al de los implantes cortos asociados con implantes más largos. O objetivo do presente estudo foi analisar a tensão e a microdeformação do tecido ósseo cortical geradas pelas forças oclusais sobre próteses de três elementos implantossuportadas, variando o fator união e comprimento dos implantes, instaladas na região posterior de maxila. Quinze modelos tridimensionais foram simulados com auxílio dos programas In Vesalius, SolidWorks 2016, Rhinoceros 4.0. Cada modelo tridimensional foi constituído de um bloco ósseo maxilar referente à região do 1º PM ao 1º M direito, apresentando três implantes do tipo hexágono externo (HE) de 4,0 mm de diâmetro, suportando prótese de três elementos metalocerâmica parafusada, variando o fator união (coroas unitárias e esplintadas: em linha reta e em posicionamento tripoidal), comprimento com implantes (10 mm, 8,5 mm e 7 mm de Ø4 mm). O programa FEMAP 11.4.2 foi utilizado para gerar os modelos de elementos finitos nas fases de pré- e pós-processamento. A análise do tecido ósseo foi feita utilizando os mapas de Tensão Máxima Principal (MPa) e Microdeformação (µε). Os maiores valores de tensão/microdeformação foram observados no carregamento oblíquo. A esplintagem associada ao posicionamento tripoidal gerou melhor comportamento biomecânico. A associação de implantes curtos com implante de maior comprimento não demonstrou benefício biomecânico. A redução do comprimento do implante (7 mm) gerou um comportamento biomecânico desfavorável. A esplintagem foi efetiva na redução de tensão/microdeformação do tecido ósseo cortical, principalmente quando associada ao posicionamento tripoidal dos implantes. O aumento do comprimento do implante diminuiu a tensão/microdeformação no tecido ósseo. Implantes curtos esplintados mostraram comportamento biomecânico similar a implantes curtos associados a implantes de maior comprimento.

Made available in DSpace on 2018-12-11T17:04:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-01-25 The aim of study was to evaluate the stress distribution in implant-supported prostheses and peri-implant bone using internal hexagon (IH) implants in the premaxillary area, varying surgical techniques (conventional, bicortical and bicortical in association with nasal floor elevation), and loading directions (0°, 30° and 60°) by three-dimensional (3D) finite element analysis. Three models were designed with Invesalius, Rhinoceros 3D and Solidworks software. Each model contained a bone block of the premaxillary area including an implant (IH, Ø4 × 10 mm) supporting a metal-ceramic crown. 178 N was applied in different inclinations (0°, 30°, 60°). The results were analyzed by von Mises, maximum principal stress, microstrain and displacement maps including ANOVA statistical test for some situations. Von Mises maps of implant, screws and abutment showed increase of stress concentration as increased loading inclination. Bicortical techniques showed reduction in implant apical area and in the head of fixation screws. Bicortical techniques showed slight increase stress in cortical bone in the maximum principal stress and microstrain maps under 60° loading. No differences in bone tissue regarding surgical techniques were observed. As conclusion, non-axial loads increased stress concentration in all maps. Bicortical techniques showed lower stress for implant and screw; however, there was slightly higher stress on cortical bone only under loads of higher inclinations (60°). Department of Dental Materials and Prosthodontics Aracatuba Dental School UNESP–Univ Estadual Paulista Department of Pediatric and Community Dentistry Aracatuba Dental School UNESP–Univ Estadual Paulista Department of Operative Dentistry School of Dentistry Federal University of Alfenas–UNIFAL-MG Department of Dental Materials and Prosthodontics Aracatuba Dental School UNESP–Univ Estadual Paulista Department of Pediatric and Community Dentistry Aracatuba Dental School UNESP–Univ Estadual Paulista

Made available in DSpace on 2018-12-11T17:02:25Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-11-17 The aim of this study was to assess stress/strain of different implant modeling simplifications by 3D-FEA. Three variation of external hexagon implant (Ã 3.75 Ã 10Â mm) supporting one molar crown were simulated: A (no threads); B (slightly threads simplification); C (original design). 200Â N (axial) and 100Â N (oblique) were applied. Cortical bone was evaluated by maximum principal stress and microstrain qualitatively and quantitatively (ANOVA and Tukey post hoc (pÂ

The aim of this study was to compare the values of bone-implant contact (BIC) and removal torque (RTQ) reported in different animal studies for titanium–zirconium (TiZr) and titanium (Ti) dental implants. This review has been registered at PROSPERO under number CRD42016047745. We undertook an electronic search for data published up until November 2017 using the PubMed/Medline, Embase, and The Cochrane Library databases. Eligibility criteria included in vivo studies, comparisons between Ti and TiZr implants in the same study, and studies published in English that evaluated BIC and RTQ. After inclusion criteria, 8 studies were assessed for eligibility. Of the 8 studies, 7 analyzed BIC outcome and 3 analyzed RTQ outcome. Among such studies, 6 studies were considered for meta-analysis of quantitative for BIC and 2 studies for RTQ. There was no significant difference for BIC analysis (P = .89; random ration [RR]: −0.21; 95% confidence interval [CI]: −3.14 to 2.72). The heterogeneity of the primary outcome studies was considered low (7.19; P = .21; I2: 30%). However, the RTQ analysis showed different results favoring the TiZr dental implants (P = .001; RR: 23.62; 95%CI: 9.15 to 38.10). Low heterogeneity was observed for RTQ (χ2: 1.25; P = .26; I2: 20%). Within the limitations of this study, there was no difference between TiZr and Ti alloys implants in terms of BIC. However, TiZr implants had higher RTQ than Ti alloys.

Made available in DSpace on 2018-12-11T17:19:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-01-01 No consensus has been reached regarding the influence of the flapless and open-flap surgical techniques on the placement of dental implants. This systematic review compared the effects of flapless implant placement and implant placement with elevation of the mucoperiosteal flap in terms of marginal bone loss, implant survival rate and complications rates. This review followed PRISMA guidelines and was registered in PROSPERO with the registration number CRD42017071475. Two independent reviewers performed a comprehensive search of the PubMed/MEDLINE, Scopus, and Cochrane Library databases for studies published until December 2017. The search identified 559 references. After a detailed review, 24 studies were assessed for eligibility. A total of 1025 patients who had received a total of 1873 dental implants were included. There were no significant differences between the flapless and open-flap surgical techniques in terms of implant survival rates (P = 0.34; risk ratio (RR): 1.36; confidence interval (CI): 0.72–2.56), marginal bone loss (P = 0.23; MD: −0.20; CI: −0.52–0.13), or complication rates (P = 0.67; RR: 1.10; CI: 0.70–1.73). The current meta-analysis showed that the implant survival rate, marginal bone levels, and complications of flapless surgery were similar to those of open-flap surgery over a mean follow-up period of 21.62 months. Department of Dental Materials and Prosthodontics Aracatuba Dental School Sao Paulo State University (UNESP) Department of Dental Materials and Prosthodontics Aracatuba Dental School Sao Paulo State University (UNESP)

Made available in DSpace on 2022-04-29T08:45:23Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-01-01 This study compared the survival rate of dental implants, amount of marginal bone loss, and rates of complications (biological and prosthetic) between short implants and long implants placed after maxillary sinus augmentation. This systematic review has been registered at PROSPERO under the number (CRD42017073929). Two reviewers searched the PubMed/MEDLINE, Embase, LILACS, and Cochrane Library databases. Eligibility criteria included randomized controlled trials, comparisons between short implants and long implants placed after maxillary sinus augmentation in the same study, and follow-up for >6 months. The Cochrane Collaboration's tool for assessing the risk of bias in randomized trials was used to assess the quality and risk of bias of the included studies. The search identified 1366 references. After applying the inclusion criteria, 11 trials including 420 patients who received 911 dental implants were considered eligible. No significant difference was observed in the survival rate [p = 0.86; risk ratio (RR): 1.08; 95% confidence interval (CI): 0.46-2.52] or in the amount of marginal bone loss (p = 0.08; RR: -0.05; 95%CI: -0.10 to 0.01). However, higher rates of biological complications for long implants associated with maxillary sinus augmentation were observed (p < 0.00001; RR: 0.21; 95%CI: 0.10-0.41), whereas a higher prosthetic complication rate for short implants was noted (p = 0.010; RR: 3.15; 95%CI: 1.32-7.51). Short implant placement is an effective alternative because of fewer biological complications and similar survival and marginal bone loss than long implant placement with maxillary sinus augmentation. However, the risk of mechanical complications associated with the prostheses fitted on short implants should be considered. Department of Dental Materials and Prosthodontics Aracatuba Dental School Universidade de São Paulo Department Prosthodontics Presidente Prudente Dental School Universidade do Oeste Paulista

Made available in DSpace on 2018-12-11T17:15:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-11-17 The aim of this study was to evaluate different materials for restoration of teeth without ferrule by three-dimensional (3D) finite element analysis (FEA). Five models simulating the maxillary central incisor and surrounding bone were simulated according to the type of post: glass fibre post (GFP) or cast metal post (CMP) with different alloys such as gold (Au), silver–palladium (AgPd), copper–aluminum (CuAl) and nickel–chromium (NiCr). Models were designed using Invesalius and Rhinoceros. FEAs were made using FEMAP and NeiNastran, with an applied axial force of 100 N and oblique occlusal load at 45°. Stress distribution among groups was analysed by two-way analysis of variance (ANOVA), followed by post-hoc Tukey’s test. The GFP showed the best stress distribution in the post, followed by CMP with Au, AgPd, CuAl and NiCr alloys, respectively (p .05). Under oblique load, the GFP generated the highest values of tension among the models, followed by the CMP with NiCr alloy than other models (p

A mordida aberta anterior é uma má oclusão caracterizada pela presença de um trespasse vertical negativo entre as bordas incisais dos dentes anteriores superiores e inferiores. A etiologia é multifatorial, entre eles estão à hereditariedade, hábitos de sucção digital e chupeta, interposição de língua e respiração bucal. Estes fatores tornam a má oclusão complexa, principalmente em relação a estabilidade, sendo necessário um tratamento multidisciplinar, envolvendo psicólogos, otorrinolaringologistas e fonoaudiólogos, para que o tratamento ortodôntico se torne mais preciso e eficiente, diminuindo o risco da instabilidade desta má oclusão. Na literatura há várias formas de tratamento, desde a utilização de aparelhos fixos mais complexos até tratamentos mais simples. O objetivo deste artigo foi descrever o tratamento estabelecido para um paciente com 13 anos de idade, apresentando uma mordida aberta anterior dentoalveolar, causada por hábito de sucção digital até os 9 anos de idade, que desencadeou uma interposição lingual e dificuldade de fonação adequada. O tratamento proposto foi uma ortodontia simples e efetiva por meio da extrusão dos dentes anteriores com o uso de elásticos intermaxilares, apoiados no aparelho ortodôntico fixo metálico pré-ajustado (Prescrição Andrews, slot 0.022”) e controle clínico mostrando estabilidade após 2 anos. O tratamento ortodôntico realizado foi satisfatório, porém é necessário destacar a importância da participação da fonoaudiologia para que houvesse estabilidade da oclusão e retorno das funções musculares à normalidade.Descritores: Má Oclusão; Ortodontia Corretiva; Fonoaudiologia; Ortodontia.

Statement of problem There is insufficient evidence to recommend the restorative material for implant-supported prostheses. Purpose The purpose of this systematic review and meta-analysis was to evaluate studies that compared ceramic and metal-ceramic restorations for implant-supported prostheses (within the same study to avoid indirect comparison) in terms of the mechanical and biological complication rates, prosthesis survival rate, and marginal bone loss. Material and methods Two independent reviewers performed a comprehensive search in databases (PubMed/MEDLINE, Web of Science, and Cochrane Library) for articles indexed until March 31, 2018. The search was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and methods were registered in the International Prospective Register of Systematic Reviews (PROSPERO). The focused question was “Do ceramic restorations have mechanical/biological complication rates, prosthesis survival rates, and marginal bone loss similar to those of metal-ceramic restorations?” Results The search identified 949 references. The interinvestigator agreement using kappa values was 0.87 for PubMed/MEDLINE, 0.93 for Scopus, and 1.0 for the Cochrane Library. After analysis, 12 studies were selected for qualitative and quantitative analysis. The mechanical complication rate did not differ between ceramic and metal-ceramic restorations (P=.89), independent of the type of prostheses (single crown: P=.63; fixed partial denture: P=.65). The biological complication rate was also not significantly different between ceramic and metal-ceramic restorations (P=.21). The prosthesis survival rate showed no significant differences between the 2 types of restorations (P=.56). Marginal bone loss was also similar for both types of restorations (P=.12). Conclusions This systematic review indicated that ceramic and metal-ceramic implant-supported prostheses have similar mechanical and biological complication rates, prosthesis survival rates, and marginal bone loss. Thus, both treatments are appropriate options for long-term rehabilitation treatment.