Three-dimensional finite element analysis of three internal tapered implant-abutment designs / Análise tridimensional de elementos finitos de três geometrias implante-abutment cônicos internos

ABSTRACT Objective: The aim of this study was to compare the stress distribution in internal tapered connection implants with different adaptation geometries submitted to oblique load simulation using the Finite Element Analysis (FEA) method. Methods: Three different internal tapered implant-abutment assemblies were modeled by varying only the diameter of the abutment body in the cone region. The dimensions of the implants were 4.0 mm in diameter and 13 mm in length. Oblique loads of 210 N angled 30 degrees to the long axis of the implant were applied to a hemispherical body positioned over the abutments simulating a dental crown. The stress generated by the implant-abutment assembly was analyzed by the FEA method using the von Mises criterion. Results: A higher concentration of stress in the coronal region (collar) and implant body on the opposite side of the load application was shown, as well as in the body region of the abutments and in the screw threads. The cervical region of the implants showed the highest von Mises stress values, the highest values being observed in G3 (1034 MPa), followed by G2 (841 MPa) and G1 (702 MPa). Conclusion: According to the results presented, it can be concluded that the stress distribution was more homogeneous and less concentrated in the G1 implant-abutment assembly. Therefore, the use of abutments with dimensions standardized by the implant manufacturer is recommended.

RESUMO Objetivo: O objetivo deste estudo foi comparar a distribuição de tensões em implantes de conexão cônica interna com diferentes geometrias de adaptação submetidos à simulação de carga oblíqua pelo método de Análise de Elementos Finitos (FEA). Métodos: Três diferentes conjuntos implante-pilar cônicos internos foram modelados variando apenas o diâmetro do corpo do pilar na região do cone. As dimensões dos implantes foram de 4,0 mm de diâmetro e 13 mm de comprimento. Cargas oblíquas de 210 N anguladas 30 graus em relação ao longo eixo do implante foram aplicadas sobre um corpo hemisférico posicionado sobre os pilares simulando uma coroa dentária. A tensão gerada pelo conjunto implante-pilar foi analisada pelo método FEA utilizando o critério de von Mises. Resultados: Foi evidenciada maior concentração de tensões na região coronal (colar) e corpo do implante no lado oposto da aplicação da carga, assim como na região do corpo dos pilares e nas roscas dos parafusos. A região cervical dos implantes apresentou os maiores valores de tensão de von Mises, sendo os maiores valores observados em G3 (1034 MPa), seguido de G2 (841 MPa) e G1 (702 MPa). Conclusão: De acordo com os resultados apresentados, pode-se concluir que a distribuição de tensões foi mais homogênea e menos concentrada no conjunto implante-pilar do G1. Portanto, recomenda-se o uso de pilares com dimensões padronizadas pelo fabricante do implante.

Peri-implant bone level assessment of early loaded dental implants submitted to different prosthetic protocols: a case report / Avaliação do nível ósseo peri-implantar de implantes dentários com carregamento antecipado submetidos a protocolos protéticos diferentes: relato de caso

Aim: The present split-mouth case report aims to describe the clinical and radiographic long-term outcomes of the implant rehabilitation of two mandibular premolars in which the digital workflow was used to apply different prosthetic protocols. Case description: A female 42-year-old patient with the absence of both mandibular second premolars was submitted to guided surgery for the placement of platform-switching Grand Morse connection implants. Digital workflow was used for implant and prosthetic planning, applying early loading protocol 21 days after surgery. The implant on the right side received the final abutment at the time of surgery (without loading), whereas the implant on the left side had a healing abutment placed, which was replaced by a temporary abutment and then by a final abutment. Two months after surgery, both implants had final ceramic restorations delivered. The patient was followed clinically and radiographically for 30 months, presenting excellent hard and soft tissue outcomes, with bone level changes lower than 2mm for both implants. Conclusion: The use of digital workflow and early loading, made the present implant-supported rehabilitation predictable, safe and time-efficient, resulting in total patient satisfaction. Peri-implant bone level was observed to be stable after early loading protocol for both platform-switching connection implants inserted, despite the prosthetic protocol applied.(AU)

Objetivo: O presente relato de caso de boca dividida tem como objetivo descrever os resultados clínicos e radiográficos a longo prazo da reabilitação com implante de dois pré-molares inferiores em que o fluxo de trabalho digital foi usado para aplicar os conceitos de "one abutment-one time" em uma das reabilitações e troca de componente no outro. Descrição do caso: Paciente do sexo feminino, 42 anos, com ausência de ambos os segundos pré-molares inferiores, foi submetida à cirurgia guiada para colocação de implantes de conexão Grand Morse plataforma-switching. Foi utilizado fluxo de trabalho digital para planejamento de implante e prótese, aplicando protocolo de carga antecipada 21 dias após a cirurgia. O implante do lado direito recebeu o componente protético definitivo no momento da cirurgia (sem carga), enquanto o implante do lado esquerdo recebeu um cicatrizador, que foi substituído por um pilar provisório e depois por um componente definitivo. Dois meses após a cirurgia, ambos os implantes tiveram restaurações cerâmicas finais entregues. A paciente foi acompanhada clínica e radiograficamente por 30 meses, apresentando excelentes resultados de tecidos duros emoles, com alterações do nível ósseo inferiores a 2mm para ambos os implantes. Conclusão: O fluxo de trabalho digital e carregamento precoce, tornou a presente reabilitação implantossuportada previsível, segura e eficiente em termos de tempo, resultando em total satisfação do paciente. O nível ósseo peri-implantar foi observado como estável após o protocolo de carregamento inicial para ambos os implantes de conexão plataforma-switching inseridos, independente do protocolo protético aplicado. (AU)

Clinical and radiographic outcomes of maxillary lateral incisors rehabilitation using Morse taper connection extra-narrow implants at 12-month follow-up: A case report.

Narrow-diameter implants (≤3.5 mm) have been proposed to address the challenge of implant placement in cases of insufficient bone quantity, thin alveolar crest, and small cervical diameter teeth replacement The aim of this study is to report one-year outcomes of extra-narrow implant rehabilitation of maxillary lateral incisors, due to agenesis, in a young adult that presented sites with reduced mesiodistal and buccolingual dimensions. A 26-year-old male patient in need of fixed-implant supported prostheses due to the absence of permanent maxillary lateral incisors and with limited space, was submitted to surgery to receive two 2.9 mm hybrid Morse taper connection implants with hydrophilic surfaces. Immediate loading was applied by means of insertion of provisional prostheses, which were replaced for all-ceramic prostheses 12 months after surgery. The 1 year follow-up showed clinical and radiographic success of extra-narrow implant rehabilitation. Also, both regions presented good evolution of peri-implant esthetics, as assesses using the pink esthetic score, with improvements at 4 months follow-up and reaching high scores 12 months after surgery. Although the prosthetic rehabilitation of maxillary lateral incisors is challenging due to limited space for the insertion of implants, the clinical case suggests that the use of extra-narrow Morse Taper implants with hybrid design and hydrophilic surface is a reliable alternative, presenting good outcomes regarding hard and soft tissue and it is a versatile solution or immediate loading procedure. Further studies are needed to confirm extra-narrow implant predictability.

Prospective Evaluation of Bone Remodeling in Full-Arch Rehabilitations with Morse Taper Implants: A Case Series Study with One-Year Follow-Up.

This case series study evaluated the survival, success rate and marginal bone remodeling of Morse taper hydrophilic implants placed for full-arch rehabilitations over a 1-year follow-up period. Ten patients in need of maxillary and/or mandibular full-arch rehabilitation were selected. Sixty-six Morse taper implants and sixty-six abutments were inserted. All implants were placed using a surgical flap approach without bone regeneration and were immediately loaded with definitive prostheses according to the passive fitting technique. The patients underwent clinical and radiographic follow-up at different postoperative periods: T0 = immediate (up to 1 month after surgery); T1 = 3-4 months after surgery; T2 = 6-8 months after surgery; and T3 = 1 year after surgery. The survival and success rate of the implants and the marginal bone remodeling were evaluated. Normal distribution of the outcomes was verified by Kolmogorov-Smirnov tests. Therefore, changes in vertical and horizontal marginal bone levels were assessed with paired t-tests. Results were considered significant for P < 0.05. Survival and success rates of 100% and 92.4%, respectively, were observed. Statistically significant vertical bone level changes were shown for all periods. From T0 to T3, there was a mean difference in vertical bone loss of -1.02 mm on the mesial surface and of -0.93 mm on the distal surface, for horizontal bone loss in the same period, it was observed mean changes of -0.14 mm on the mesial surface and -0.09 mm on the distal surface. This 1-year case series follow-up of immediate full-arch rehabilitation, using one-step hybrid passive fitting supported by four to six hydrophilic tapered implants, suggests predictability with high survival and success rates in edentulous patients.

Implant Osseointegration in Grafted Autogenous Bone Blocks Fixed with Screws and Cyanoacrylate-Based Adhesive: Histomorphometric and Micro-CT Analyses.

PURPOSE: To evaluate implant osseointegration in grafted autogenous bone blocks fixed with cyanoacrylate-based adhesive and screws. Also, grafted bone fixed either with an adhesive or screw was evaluated. MATERIALS AND METHODS: Two surgical defects in the parietal region of rabbits (n = 12) were performed in each animal. Autogenous bone blocks obtained were fixed anteriorly with a screw or cyanoacrylate-based adhesive. After 30 and 45 days of grafting procedures, implants were placed in bone blocks. Histomorphometric and microcomputed tomography (micro-CT) analyses of the implant area were performed at 30 days after implant surgery in the screw (n = 6) and adhesive (n = 6) groups. Histomorphometric analyses of bone-grafted areas were performed at 60 and 75 days in the screw (n = 6) and adhesive (n = 6) groups. Histomorphometric evaluations were carried out in implant and grafted bone areas. The micro-CT parameters evaluated were bone-to-implant contact, bone area fraction occupancy, bone volume fraction, trabecular thickness, trabecular separation, and trabecular number. RESULTS: No differences were observed in the micro-CT parameters for the screw and adhesive groups in all experimental periods. However, an increased quantity of immature bone volume was observed on the adhesive group in the grafted area after 75 days. The grafted area in the screw group (75 days) presented a decrease in the volume density of the immature bone compared with the screw group (60 days). There were no differences in both groups and experimental periods in soft tissue in the grafted area. CONCLUSION: No differences were observed in the osseointegration of implants placed in grafted autogenous bone blocks fixed with cyanoacrylate-based adhesive and screws. Therefore, osseointegration in autogenous bone fixed with cyanoacrylate-based adhesive is viable.

Retrospective Multivariate Clinical Analysis of 2707 Dental Implants with Hydrophilic and Hydrophobic Surfaces: Survival Rates after Up to 5 Years.

The aim of this retrospective study was to evaluate the long-term predictability of treatment using implants with hydrophobic and hydrophilic surfaces, according to clinical parameters and survival rates. Records from all patients who received dental implants between January 2013 and December 2014 at ILAPEO College were fully evaluated by two graduate dentists. Records with incomplete or unclear data were excluded from the study. The variables evaluated were demographic data, design of implants and prosthetic components, type of loading, data related to the patients' general health, and survival of implants and prostheses. The final retrospective sample comprised 776 patients with 2707 implants, with up to 5 years of follow-up. Survival rates of implants and prostheses were 97.93% and 98.77%, respectively. Implants with hydrophobic (97.87%) and hydrophilic (98.34%) surfaces exhibited similar survival rates. Considering the different types of loading, there was no statistically significant difference between loading protocols regarding implant survival rates. Unsuitable healing capacity, uncooperative and not motivated patient, loss of prosthesis, and peri-implant bone loss were confirmed statistically to be factors that may contribute to implant loss, according to hazard ratio and odds ratio. The present study showed similar and high overall survival rates for implant with both types of surfaces, in the long term. The surface treatment, implant model and loading protocol had no significant influence on implant loss. Therefore, the evaluated implant systems were able to offer a high predictability for both hydrophobic and hydrophilic implants.

Clinical and radiographic success of injection-molded 2-piece zirconia implants submitted to immediate loading: A 12-month report of two cases.

This case report describes the treatment of two patients who presented with single edentulous sites in the region of upper premolars and were rehabilitated through the placement of injection-molded 2-piece zirconia implants and immediate single crowns. Three months after surgery, definitive prostheses were confectioned through digital workflow. Both patients were followed for 12 months during which clinical and radiographic implant success were observed, concerning implant stability, absence of peri-implantitis signs, complete implant osseointegration, good marginal bone-level maintenance, and excellent soft tissue esthetics. No biological or mechanical complications were observed within this period.

Implant and prosthesis survival rates of full-arch immediate prostheses supported by implants with and without bicortical anchorage: Up to 2 years of follow-up retrospective study.

OBJECTIVES: To compare implant and prosthesis survival rates between full-arch immediate prostheses supported by 4 hydrophilic implants with bicortical anchorage and by 5 or 6 hydrophilic implants placed without bicortical anchorage. MATERIAL AND METHODS: The sample was retrospectively selected and comprised completely edentulous patients treated with full-arch immediate prostheses supported by Morse Taper hydrophilic implants. The selected patients were divided into four groups, according to the region of implant placement and type of anchorage. Differences in implant and prosthesis survival rates between groups, as well as the influence of bicortical anchorage on implant primary stability, were verified using Fisher's exact tests (significant at p < .05). RESULTS: The sample comprised 392 implants, 72 were placed in the maxilla with bicortical anchorage, and 85 were placed without. In the mandible, 140 implants were placed with and 95 were placed without bicortical anchorage. The follow-up period was up to 24 months. A 98.8% implant survival rate was observed for the group of implants placed without bicortical anchorage in the maxilla, and of 100% for the other groups. The overall implant survival rate was 99.7% (391 of 392 implants). Prosthesis survival rate was 100% for all groups. No differences were observed between groups with respect to implant and prosthesis survival rates. Significantly higher primary stability was observed for implants placed with bicortical anchorage in both jaws. CONCLUSION: Predictable results and high survival rates were achieved within the period evaluated by the present retrospective study, with immediate full-arch prostheses when only four hydrophilic implants are placed bicortically.

Simplificação da técnica para reabilitação de maxila atrófica com implantes zigomáticos com interface cônica interna e carregamento imediato: relato de caso / Simplification of the technique for rehabilitation of atrophic upper jaw with zygomatic implants with internal tapered interface and immediate loading: case report

A reabilitação de maxilas atróficas com implantes dentários é sempre um desafio, visto que o uso de enxertos ósseos é quase sempre necessário para estabilização dos implantes. Os implantes zigomáticos têm sido utilizados como uma opção viável ao uso de procedimentos de enxertia óssea anterior à cirurgia. A interface cônica interna apresenta gap reduzido entre implante e componente protético, mostrando resultados biológicos e estéticos satisfatórios a longo prazo. Este artigo tem como objetivo relatar a reabilitação protética imediata de uma maxila atrófica com implantes convencionais e zigomáticos com interface cônica interna como opção ao uso de enxertos ósseos prévios. Paciente com 47 anos de idade, do sexo masculino, apresentava maxila atrófica e usava uma prótese total superior. O paciente foi reabilitado com quatro implantes convencionais na região anterior e dois implantes zigomáticos cônicos internos instalados nos ossos zigomáticos. Os torques de instalação dos implantes ≥ 60 N.cm proporcionaram estabilidade primária ideal e uma prótese (protocolo) foi instalada imediatamente utilizando a técnica do assentamento passivo. O caso clínico apresentado mostrou que, após 1 ano, resultados precisos e estéticos são possíveis de alcançar com a instalação de implantes zigomáticos combinados com implantes convencionais para reabilitação de maxilas atróficas de forma imediata e sem utilização de enxerto ósseos prévios.

The rehabilitation of atrophic upper jaws with dental implants is always a challenge, since the use of bone grafts is almost always necessary to stabilize the implants. Zygomatic implants have been used as a viable option for the use of bone grafting procedures prior to surgery. The internal tapered interface presents a reduced gap between implant and prosthetic component, showing satisfactory long-term biological and aesthetic results. This article aims to report the immediate prosthetic rehabilitation of an atrophic upper jaw with conventional and zygomatic implants with an internal tapered interface as an option for the use of previous bone grafts. A 47-year-old male patient presented with an atrophic upper jaw and used an upper total prosthesis. The patient was rehabilitated with four conventional implants in the anterior region and two internal tapered zygomatic implants placed in the zygomatic bones. The implant placement torques ≥ 60 N.cm provided ideal primary stability and a prosthesis (protocol) was installed immediately using the passive fit technique. The clinical case presented showed that, after 1 year, accurate and aesthetic results are possible to achieve with the placement of zygomatic implants combined with conventional implants for the rehabilitation of atrophic upper jaws immediately and without the use of previous bone grafts.

Guided osteotomy and implants placed with free hands for double full arch rehabilitation with immediate prosthetic loading / Osteotomia guiada e implantes instalados com as mãos livres para reabilitação de arco duplo total com carga protética imediata

ABSTRACT Precise planning for dental implant placement requires appreciation of anatomical limitations and restorative purpose. Diagnosis can be made by complementary exams such as panoramic radiography and cone-beam computed tomography. The purpose of this study was to rehabilitate the upper and lower jaw of a patient with severe periodontal disease using a guided osteotomy and implants placed with free hands and Morse taper implants. The concept of guided surgery was used to prepare the alveolar bone to place eight implants, four implants in the upper jaw and four implants in the lower jaw, all have achieved a minimum torque of 60 Ncm. The modified suture technique was used to better stabilize the soft tissue around the mini conical abutments. The analogues were scanned by CAD/CAM for confection of the metallic structures of the bridges. On the third day, the upper and lower full arch prostheses were installed and simultaneous bilateral contacts were adjusted. After 12 months of patient follow-up, the implants and prostheses were in good condition of aesthetics and function, maintaining the success of the rehabilitation. Within the limitations of this clinical case, it can be concluded that the implants placed with free hands was facilitated by a previous guided osteotomy.

RESUMO O planejamento preciso para a instalação de implantes dentários requer a apreciação das limitações anatômicas e objetivos restaurativos. O diagnóstico pode ser feito por exames complementares, como radiografia panorâmica e tomografia computadorizada de feixe cônico. O objetivo deste estudo foi reabilitar, a mandíbula superior e inferior de um paciente com doença periodontal severa, utilizando uma osteotomia guiada e implantes cone Morse instalados com as mãos livres. O conceito de cirurgia guiada foi utilizado para preparar o osso alveolar para a instalação de oito implantes, quatro implantes no maxilar superior e quatro implantes no maxilar inferior, todos alcançando um torque mínimo de 60 Ncm. A técnica de sutura modificada foi utilizada para melhor estabilizar o tecido mole ao redor dos mini-pilares cônicos. Os abutments foram escaneados por CAD/CAM para confecção das estruturas metálicas das próteses dentárias. No terceiro dia, as próteses de arco superior e inferior foram instaladas e os contatos bilaterais simultâneos foram ajustados. Após 12 meses de acompanhamento do paciente, os implantes e próteses estavam em boas condições de estética e função, mantendo o sucesso da reabilitação. Dentro das limitações deste caso clínico, pode-se concluir que os implantes instalados com as mãos livres foram facilitados pelo uso prévio da osteotomia guiada.

Previsibilidade na Instalação Imediata de Implante Cone Morse pelo Planejamento Digital e Provisionalização Imediata: Relato de Caso / Predictability in Immediate Implant Placement of Morse Taper by Digital Planning and Immediate Provisionalization: Case Report

A instalação imediata de implantes em região estética é uma prática frequente, pois reduzir a remodelação óssea e tecidual. Os implantes com interface cone Morse apresentam resultados biológicos e estéticos satisfatórios a longo prazo, pois apresentam gap reduzido entre implante e componente protético e a interface fica distante do tecido ósseo. Este artigo tem como objetivo relatar a reabilitação estética de um incisivo central superior comprometido através da instalação de um implante cone Morse utilizando a técnica da cirurgia guiada com provisionalização imediata. Paciente com 40 anos de idade, do sexo masculino, apresentava incisivo central superior (#21) com tratamento endodôntico prévio, recessão gengival vestibular, escurecimento coronário e mobilidade. O caso clínico apresentado mostrou que, após 12 meses, resultados precisos e estéticos são possíveis de alcançar com a instalação de implantes em alvéolos pós-extração e instalação de um dente provisório imediato em regiões estéticas.

The immediate placement of implant in fresh sockets in the aesthetic area is a frequent practice as it reduces bone and tissue remodeling. Morse taper implants present satisfactory biological and aesthetic results in the long term, since they present a reduced gap between implant and prosthetic component and this interface is distant from bone. This article aims to report the aesthetic restoration of a compromised central upper incisor with the placement of a Morse taper implant using guided surgery with immediate provision. A 40-year-old male patient had a central upper incisor (#21) with previous endodontic treatment, vestibular gingival recession, coronary browning, and mobility. The clinical case presented showed that, after 12 months, precise and aesthetic results are possible to achieve with the placement of implants in post-extracting alveolus and installation of an immediate provisional tooth in esthetic regions.

Fracture Strength of Standard and Small Diameter Prosthetic Abutments for Full-Arch Implant-Supported Restorations.

This study tested the fracture strength of prosthetic abutments with different sizes and combinations to support a 5-implant milled framework with distal extension. Prosthetic abutments with different dimensions (4.8-mm diameter mini conical abutment and 3.5-mm diameter microconical abutment) were screwed to 5 threaded implants. The following groups were divided (n = 3): G1 with 5 miniconical abutments (standard size), G2 with 5 microconical abutments (small sized), G3 with a combination of 3 small sized abutments and 2 standard sized abutments, and G4 with a combination of 2 small sized abutments and 3 standard sized abutments. Standardized titanium frameworks for full-arch fixed dental prosthesis were milled with equidistant holes for each of the 5 implants and abutments. A loading point was selected at 18 mm away from both distal implants. A universal testing system was used for the fracture strength tests and load was applied at a crosshead speed of 0.5 mm/min on the previously described loading points until component fracture. Mean fracture strength for each group was statistically compared (α = 0.05). Prosthetic screws were the only fractured components for all tested groups. Mean fracture strength was: G1, 1130.22 N; G2, 1031.36 N; G3, 757.9 N; and G4 792.03 N (P < .05). All prosthetic abutments and combinations that were tested provide adequate fracture strength for clinical use. However, the combination of standard and small diameter abutments leads to lower fracture strength compared with when only standard sized prosthetic abutments were used, irrespective of the abutment diameter (4.8- or 3.5-mm).

Effect of different implant placement depths on crestal bone levels and soft tissue behavior: a randomized clinical trial.

OBJECTIVES: This randomized clinical trial analyzed crestal bone changes and soft tissue dimensions surrounding implants with an internal tapered connection placed in the mandible anterior region at different depths (equicrestal and subcrestal). MATERIALS AND METHODS: Eleven edentulous patients (five implants per patient) were randomly divided in a split-mouth design: G1, 28 equicrestal implants; and G2, 27 subcrestal implants. All implants were immediately loaded. Correlation between keratinized tissue width (KTW) and vertical mucosa thickness (MT) with soft tissue recession was analyzed. Intraoral radiographs were used to evaluate crestal bone changes. Patients were assessed immediately, 4-, and 8-months after implant placement. Rank-based ANOVA-type statistical test was used for comparison between groups (α = 0.05). RESULTS: Fifty-five implants (G1 = 28 and G2 = 27) were assessed in 11 patients. Implant survival rate was 100% for both groups. Both tested implant placement depths presented similar crestal bone loss (P > 0.05). Significant crestal bone loss for each group was found in the different measurement times (T4 and T8) (P < 0.05). Implant placement depths, KTW, and vertical MT had no effect on soft tissue recession (P > 0.05). CONCLUSIONS: Different implant placement depths do not influence crestal bone changes. Soft tissue behavior is not influenced by different implant placement depths or by the amount of keratinized tissue.

Estudo observacional retrospectivo sobre o índice de sobrevivência de implantes com superfície com aumento de molhabilidade / A retrospective observational study of the survival rate of implants with larger wettability surface

O propósito desse estudo foi avaliar, retrospectivamente, o índice de sobrevivência de implantes com tratamento de superfície para aumento de molhabilidade instalados em ambos os maxilares e submetidos ou não à carga imediata. Um total de 78 pacientes (17 homens e 61 mulheres), nos quais 182 implantes foram instalados, compuseram a amostra. Todos os implantes foram instalados em pacientes com diferentes situações clínicas, podendo ser reabilitações unitárias, parciais ou totais, nos cursos de pós-graduação do Instituto Latino Americano de Pesquisa e Ensino Odontológico (ILAPEO), entre 2011 e 2015. Cento e dezenove implantes (65,38%) foram instalados em maxila e 63 (34,61%) em mandíbula, sendo que em 156 (85,71%) foi aplicada carga imediata. O índice de sobrevivência total foi de 98,90% (180 implantes). Houve perda de apenas 2 implantes instalados em maxila. A perda foi constatada após 5 semanas em ambos os casos. Consideradas as características do estudo, a metodologia aplicada, o tamanho e as características da amostra, o tempo de acompanhamento, bem como a diversidade de variáveis daí decorrentes, parece aceitável concluir, com base nos resultados aqui encontrados e discutidos, que os implantes com tratamento de superfície com aumento de molhabilidade, ora observados, apresentaram altas taxas de sobrevivência dentro dos critérios estabelecidos neste estudo (AU).

The aim of this study was to evaluate, retrospectively, the survival rates of implants with surface treatment that increased wettability, installed in both jaws, and submitted or not to immediate loading. The sample was composed of 78 patients (17 men and 61 women), in which 182 implants were installed. All implants were installed by dentists in post-graduate courses of the Latin American Institute of Research and Dental Education (ILAPEO), between 2011 and 2015. One hundred and nineteen implants (65.38%) were installed in the maxilla and 63 (34.61%) in the mandible, and 156 (85.71%) was applied immediate load. The overall survival rate was of 98.90% (180 implants). Only 2 implants placed in the maxilla were lost, and in both cases the loss was noticed after 5 weeks. Considering the parameters of the study, the methodology, sample size and characteristics, follow-up period and diversity of the variables, it seems acceptable to conclude, based on the present discussed results, that the implants with surface treatment with increased wettability, presented high survival rates according to the criteria considered in this study (AU).

Marginal and internal fit of zirconia copings obtained using different digital scanning methods.

The objective of this study was to evaluate the marginal and internal fit of zirconia copings obtained with different digital scanning methods. A human mandibular first molar was set in a typodont with its adjacent and antagonist teeth and prepared for an all-ceramic crown. Digital impressions were made using an intraoral scanner (3Shape). Polyvinyl siloxane impressions and Type IV gypsum models were also obtained and scanned with a benchtop laboratory scanner (3Shape D700). Ten zirconia copings were fabricated for each group using CAD-CAM technology. The marginal and internal fit of the zirconia copings was assessed by the silicone replica technique. Four sections of each replica were obtained, and each section was evaluated at four points: marginal gap (MG), axial wall (AW), axio-occlusal edge (AO) and centro-occlusal wall (CO), using an image analyzing software. The data were submitted to one-way ANOVA and Tukey's test (α = 0.05). They showed statistically significant differences for MG, AO and CO. Regarding MG, intraoral scanning showed lower gap values, whereas gypsum model scanning showed higher gap values. Regarding AO and CO, intraoral digital scanning showed lower gap values. Polyvinyl siloxane impression scanning and gypsum model scanning showed higher gap values and were statistically similar. It can be concluded that intraoral digital scanning provided a lower mean gap value, in comparison with conventional impressions and gypsum casts scanned with a standard benchtop laboratory scanner.

Stress Over Implants of One-Piece Cast Frameworks Made With Different Materials.

This study aims to compare stress transmitted to implants and passive fit of one-piece cast frameworks fabricated with 3 different materials: commercially pure titanium (G1-CP Ti), cobalt-chromium alloy (G2-Co-Cr), and nickel-chromium-titanium alloy (G3-Ni-Cr-Ti). In total, 12 frameworks simulating bars for fixed prosthesis in a model with 5 implants were fabricated. The passive fit of the framework interface was measured using an optical microscope and the stresses transmitted to implants were measured using quantitative photoelastic analysis. Data were statistically analyzed by analysis of variance (ANOVA) and least significant difference (LSD) tests (α = 0.05). Mean and standard deviation values of passive fit and stress over implants are presented, respectively: G1 [472.49 (109.88) µm and 11.38 (9.23) KPa], G2 [584.84 (120.20) µm and 15.83 (9.30) KPa], and G3 [462.70 (179.18) µm and 16.39 (9.51) KPa]. For stress over implants, there were significant differences between G1, G2, and G3 (P = 0.035), being the lowest values for the G1. There were no significant differences for passive fit between G1 and G3 (P = 0.844), but both were statistically different from G2 (P = 0.028 and P = 0.035, respectively), which showed the worse results. It may be concluded that the stress over implants was affected by the tested materials. The CP Ti presented the best values for the evaluated items.

Marginal and internal fit of zirconia copings obtained using different digital scanning methods

Abstract The objective of this study was to evaluate the marginal and internal fit of zirconia copings obtained with different digital scanning methods. A human mandibular first molar was set in a typodont with its adjacent and antagonist teeth and prepared for an all-ceramic crown. Digital impressions were made using an intraoral scanner (3Shape). Polyvinyl siloxane impressions and Type IV gypsum models were also obtained and scanned with a benchtop laboratory scanner (3Shape D700). Ten zirconia copings were fabricated for each group using CAD-CAM technology. The marginal and internal fit of the zirconia copings was assessed by the silicone replica technique. Four sections of each replica were obtained, and each section was evaluated at four points: marginal gap (MG), axial wall (AW), axio-occlusal edge (AO) and centro-occlusal wall (CO), using an image analyzing software. The data were submitted to one-way ANOVA and Tukey's test (α = 0.05). They showed statistically significant differences for MG, AO and CO. Regarding MG, intraoral scanning showed lower gap values, whereas gypsum model scanning showed higher gap values. Regarding AO and CO, intraoral digital scanning showed lower gap values. Polyvinyl siloxane impression scanning and gypsum model scanning showed higher gap values and were statistically similar. It can be concluded that intraoral digital scanning provided a lower mean gap value, in comparison with conventional impressions and gypsum casts scanned with a standard benchtop laboratory scanner.

Immediate Loading of Edentulous Mandible With Prefabricated Bars: A Long-Term Study of 7 Years.

PURPOSE: To present clinical data from a 7-year follow-up study of edentulous mandibles rehabilitated according to an immediate loading protocol with prefabricated bars. MATERIALS AND METHODS: Forty-four implants were inserted in 11 patients and were evaluated by means of resonance frequency analysis (RFA) and clinical and radiographic examination. RESULTS: Ten patients returned for the 7-year evaluation and presented no implant loss. The stability measurements were performed immediately after implant placement (T0 = 64.5 ± 6.6 ISQ) and 1 year (T1 = mean 66.8 ± 4.2 ISQ), and 7 years (T7 = mean 62.8 ± 5.4) after being in function. The analysis of the RFA values showed a statistically significant decrease in implant stability after 7 years in function, although the final values are considered adequate for treatment success. Panoramic x-ray examination showed bone loss greater than the first thread in 10 implants. CONCLUSION: According to the obtained data, it can be concluded that immediate loading according to this protocol with prefabricated bars is a valid treatment option for edentulous patients providing sufficient long-term success.

Resources to achieve esthetics in anterior teeth / Recursos para se obter estética em áreas anteriores

As dentistry has evolved, the search for good esthetics has become increasingly frequent. Professionals must be constantly up-to-date regarding the latest advances. When a tooth is lost, there are several possible rehabilitation techniques. Adequate contour of the bone and gingiva is an essential factor if good esthetic results are to be achieved. In order to maintain the contour, techniques for immediate placement of implants, bone and gum grafting techniques and care in the correct establishment of the ideal position of the implant have been advocated. Sometimes dentists have to treat a patient whose implants have already been installed and are osseointegrated. This report was carried out in order to highlight the importance of understanding the information that is available to obtain appropriate gingival contours in such clinical conditions. A review of the literature was carried out on methods for obtaining gingival papilla and esthetics in the anterior maxilla, and on methods to construct a prosthesis for the clinical case described. The analysis of the outcome and of the degree of patient satisfaction suggests that the resources described can be successfully applied.

Devido às mudanças ocorridas pela evolução da Odontologia, a busca pela estética tem se tornado cada vez mais frequente. A constante atualização dos profissionais é uma necessidade. Quando ocorre a perda de um elemento dental, várias técnicas têm sido sugeridas para a correta reabilitação do mesmo. Manutenção do contorno ósseo e gengival já é um fator entendido como imprescindível para que a mesma possa ser alcançada. Em busca dessa manutenção de contorno, técnicas de posicionamentos imediatos de implantes, técnicas de enxertia óssea e/ou gengival e cuidados no correto estabelecimento da posição ideal do implante tem sido descritos. No entanto, alguns casos chegam para reabilitação com implantes já instalados e osseointegrados. Entendendo a importância de se conhecer os recursos descritos para obtenção de contornos gengivais adequados frente a essa condição clínica esse estudo foi idealizado. Foi realizada uma revisão de literatura e alguns dos métodos descritos para obtenção de papilas gengivais e estéticas em maxila anterior, assim como para confecção da prótese foram utilizados para resolução de um caso clínico que é apresentado. A análise do caso finalizado e a observação do grau de satisfação da paciente com o resultado alcançado permitem concluir que os recursos descritos são aplicáveis e permitem a otimização dos resultados.