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OBJECTIVES: This study aimed to compare the success and survival rates of metal-ceramic crowns and composite resin restorations applied in root filled teeth that received a glass fiber post. METHODS: A prospective, randomized controlled trial, with equivalent parallel groups was designed. Eighty-two teeth were randomly allocated to the metal-ceramic or composite resin groups. Multivariate Cox regression analysis with shared frailty for patients and Kaplan-Meier curves were performed using success and survival rates (p<0.05). RESULTS: Seventy-five post-retained restorations (34 metal-ceramic crowns and 41 composite restorations) in 62 patients were analyzed. The median follow-up was 8.1 years [IQR 4.0-9.9]. Twenty-seven failures were observed. Twenty-two failures (81.5 %) were observed in the composite resin group, of which six (27.3 %) were not repairable. Five failures (18.5 %) were observed in the metal-ceramic crown group, of which three (66.6 %) were non-repairable. The cumulative success rate at 8 years was 85.0 % for crowns (AFR=1.31 %) and 43.2 % for composite resins (AFR=6.58 %), while the survival rate was 93.8 % for crowns (AFR=0.52 %) and 97.6 % for composite resins (AFR=0.20 %). Considering the success rates, adjusted multivariate Cox regression showed that composite resin had a Hazard Ratio of 5.07 (95 %CI, 1.99-12.89) greater than the metal-ceramic crown. No significant difference in the failure risk was observed when the survival rates were considered (HR=0.38, 95 %CI (0.10 - 1.44), p = 0.156). Co-variables did not affect the success and survival rates (p>0.05). CONCLUSIONS: Metal-ceramic crowns showed a higher success rate than composite restorations. The survival rates were similar, but composite restorations presented a higher need for repairs. CLINICAL SIGNIFICANCE: Post-retained composite restorations may need more reinterventions during the lifecycle, although more preservation of sound tooth structure is expected with a large restoration of resin post-and-core. These aspects have to be discussed with the patient for decision-making planning.

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INTRODUCTION: Long-term clinical success of non-splinted, posterior, and short implants still is unclear. This prospective cohort study reports the 10-year follow-up of 6-mm implants supporting single crowns in the posterior region, and patient-reported outcomes. METHODS: Baseline sample comprised 20 patients treated with 46 screw-retained crowns supported by 6-mm implants with moderately rough implant surface. Participants were recalled for a 10-year clinical follow-up to assess survival rates, biologic and mechanic conditions, quality of life (OHIP-14), and treatment satisfaction. Data were collected with clinical-radiographic exams and analyzed using descriptive and inferential statistics. RESULTS: Fourteen patients with 35 implant-crown units were examined after 127.6 ± 11.8 months. For the entire cohort period, 7/46 implants were lost (survival estimate: 77.7% at 133 months), and mechanic complications occurred in 14/46 units (survival estimate: 66.4% at 116 months). In the Cox models, "maximum occlusal force" had a significant effect for implant loss (p = 0.038) and for prosthetic screw loosening (p = 0.038); "arch" and "bruxism" were not significant. Peri-implant bone loss was 0.4 ± 0.6 mm at 10 years. For peri-implant bone level, "crown-to-implant ratio" (p < 0.001) and "time" (p = 0.001) were significant. Bone levels differed from baseline to 12, 48, and 120 months. Satisfaction VAS was 94.0 ± 7.9 mm and OHIP-14 was 2.3 ± 2.2. CONCLUSION: Single screw-retained crowns supported by 6-mm implants have an acceptable long-term clinical performance, with stable peri-implant bone levels after 10 years of function.

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OBJECTIVES: To evaluate the peri-implant tissue changes and esthetic outcomes of cemented and screw-retained crowns of single-tooth implants in the esthetic zone using zirconia abutments. MATERIAL AND METHODS: An electronic search was performed on nine databases. The risk-of-bias was assessed by the revised Cochrane risk-of-bias tool for randomized (RoB 2) and non-randomized (ROBINS-I) clinical trials. Marginal bone level change, soft tissue thickness, bleeding on probing, probing depth, survival rates of implants and crowns, complications, plaque and papilla indexes, and pink esthetic score data were extracted and analyzed. The certainty of evidence was accessed through the GRADE approach. RESULTS: Nine records were included and 7 were used in the meta-analyses. Screw-retained crowns presented greater marginal bone level change (MD -0.04 [-0.08, -0.00] p = 0.04, I2  = 0%) compared to cemented crowns up to 1-year. At 3 and 4 years no significant differences (p > 0.05) were observed. Soft tissue thickness did not differ between groups (p > 0.05). The bleeding on probing was higher in cemented group than in screw-retained crowns at 1-year (MD 0.17 [0.08, 0.27] p = 0.0005, I2  = 0%), at medium-term periods (3 and 4 years) no statistically significant differences (p > 0.05) were observed for this outcome. Probing depth, survival rates of implants and crowns, complications, and plaque index, as well as esthetic analysis using the papilla index and pink esthetic score did not differ statistically (p > 0.05) between both retention systems at short and medium-term periods. CONCLUSION: The connection system considering zirconia abutments presented no influence on peri-implant parameters and esthetics evaluation for medium-term periods (3 and 4 years).

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Abstract This in silico study evaluated the influence of the abutment collar height and implants length on the biomechanical behavior of morse taper single dental implants with different crown-to-implant ratio. Six virtual models were constructed (S11, M11, L11, S13, M13 and L13) by combining short (S: 2.5 mm), medium (M: 3.5 mm) or long (L: 4.5 mm) abutment collar heights with different implant lengths (11 or 13-mm). An upper central incisor of 11-mm height was constructed on top of each abutment. Each set was positioned in a virtual bone model and exported to analyze mathematically. A 0.60-mm mesh was created after convergence analysis and a 49 N load was applied to the cingulum of the crown at an angle of 45°. Load-generated stress distribution was analyzed in the prosthetic components according to von Mises stress criteria (σvM) and in the cortical and cancellous bone by means of shear stress (εmax). The use of longer collar abutments (L11) increased the stress on the abutment by 250% and resulted in 40% higher stresses on the screw and 92% higher cortical shear stresses compared to short collared abutments (S11). Increasing the implant length produced a slight stress reduction on cortical bone. Cancellous bone was not affected by the crown-to-implant ratio. Longer abutment collars concentrate stresses at the implant level and cortical bone by increasing the crown-to-implant ratio.

Resumo Este estudo avaliou a influência da altura da porção transmucosa do pilar protético com junção cone morse e do comprimento dos implantes no comportamento biomecânico coroas unitárias com diferentes proporção coroa-implante. Seis modelos virtuais (S11, M11, L11, S13, M13 e L13) foram construídos combinando pilares protéticos com transmucoso considerado: curto (S: 2,5 mm), médio (M: 3,5 mm) ou longo (L: 4,5 mm) com diferentes comprimentos de implantes (11 ou 13 mm). Um incisivo central superior de 11 mm de altura foi construído para cada pilar. Cada conjunto foi posicionado em um modelo de osso virtual e exportado para análise matemática. Uma malha de 0,60 mm foi criada após análise de convergência e uma carga de 49 N foi aplicada ao cíngulo da coroa em um ângulo de 45°. A distribuição de estresse gerada por carga foi analisada nos componentes protéticos de acordo com o critério de tensão de von Mises (σvM) e no osso cortical e medular por meio da tensão de cisalhamento (εmax). O uso de pilares com porção transmucosa mais longa (L11) aumentou a tensão no pilar protético em 250%, e resultou em tensões 40% maiores no parafuso e 92% no osso cortical em relação aos pilares com transmucoso curto (S11). O aumento do comprimento do implante produziu uma ligeira redução da tensão de cisalhamento no osso cortical. O osso medular não foi afetado pela relação coroa-implante. Pilares protéticos com porção transmucosa mais longa concentram tensões no implante e no osso cortical, quando a proporção coroa-implante é aumentada.

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OBJECTIVE: This in vitro study aimed to evaluate marginal and internal fit of single crowns produced from high-frequency ultrasound based digital impressions of teeth prepared with finish lines covered by porcine gingiva, in comparison with those obtained by optical scanners with uncovered finish lines. METHODS: Ten human teeth were prepared and forty zirconia crowns were fabricated from STL-datasets obtained from four dental scanners (n=10): extraoral CS2 (Straumann), intraoral Lava COS (3M), intraoral Trios (3Shape) and extraoral ultrasound scanner. The accuracy of the crowns was compared evaluating marginal and internal fit by means of the replica technique with measurements in four areas; P1: occlusal surface; P2: transition between occlusal and axial surfaces; P3: middle of axial wall; and P4: marginal gap. Restoration margins were classified according to their mismatch as regular, underextended or overextended. Kruskal-Wallis one-way ANOVA and Mann-Whitney U test were used to evaluate the differences between groups at p<0.05. RESULTS: The median value of marginal gap (P4) for Ultrasound (113.87µm) differed statistically from that of CS2 (39.74µm), Lava COS (41.98µm) and Trios (42.07µm). There were no statistical differences between ultrasound and Lava COS for internal misfit (P1-P3), however there were statistical differences when compared with the other two scanners (Trios and CS2) at P1 and P2. SIGNIFICANCE: The ultrasound scanner was able to make digital impressions of prepared teeth through porcine gingiva (P4), however with less accuracy of fit than that of conventional optical scanners without coverage of the finish lines. Where no gingiva was available (P1-P3), the ultrasound accuracy of fit was similar to that of at least one optical scanner (Lava COS).

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Este estudo avaliou os assentamentos marginal e interno em 4 áreas predeterminadas de coroas totais à base de dissilicato de lítio produzidas por 3 fluxos de trabalho distintos. Um modelo-mestre de titânio com um preparo para coroa total em um molar foi confeccionado. Foram produzidas 36 coroas totais à base de dissilicato de lítio. As coroas foram divididas em 3 grupos, de acordo com o fluxo de trabalho: Totalmente Convencional (TC): moldagem do modelo-mestre com polieter, vazagem com gesso tipo IV e confecção de 12 coroas (IPS e.max PRESS) no laboratório de prótese; Totalmente Digital (TD): escaneamento do modelo-mestre com a Bluecam™ e usinagem de 12 coroas totais (IPS e.max CAD™) no CEREC 3™; e Parcialmente Digital (PD): moldagem do modelo-mestre com polieter, vazagem com gesso tipo IV, escaneamento do modelo de gesso com a Bluecam™ e usinagem de 12 coroas totais (IPS e.max CAD™) no CEREC 3™. Para a avaliação do assentamento foi utilizada a técnica da réplica, onde a base leve do silicone de adição simulou um cimento. Duas réplicas por coroa total foram confeccionadas, gerando imagens de interfaces vestíbulo-palatal e mesio-distal sob magnificação de 50x. Quatro áreas foram definidas para a avaliação: Abertura Marginal (AM); Chanfro (CH); Parede Axial (PA); e Parede Oclusal (PO). Um software realizou a medição dos valores em toda a área demarcada, gerando aproximadamente 6.000 pontos de avaliação por interface. Os resultados foram estatisticamente analisados por meio dos testes One-Way-Anova e Scheafer's Post-Hoc, com grau de significância estabelecido em 5%. Todas os grupos testados no estudo apresentaram médias de valores clinicamente aceitáveis para os assentamentos marginal e interno. Não houve diferença significativa em AM, CH e PO entre os três grupos testados. Em PA, o grupo TC apresentou valores significativamente maiores do que PD e TD (p = 0,001). Os diferentes fluxos de trabalho, convencional ou digitais, aplicados neste estudo, foram capazes de prover adequados assentamentos marginal e interno, dentro dos valores clínicos estabelecidos para coroas totais à base de porcelana.

The aim of this study was to evaluate the marginal and internal fit of porcelain indirect restorations produced by three distinct workflows in four pre-determined interface areas. A titanium master model - simulating a full crown molar preparation - was built to this study. 36 lithium dissilicate full crowns coverage were produced. The restorations were divided in 3 groups, according to the workflow: Totally Conventional (TC), where a polieter impression of the master model was poured with type IV gypsum, and 12 full crown coverages (IPS e.max PRESS™) were produced in the dental technician; Totally Digital (TD), where the master model was scanned with the Bluecam™ and 12 full crown coverages (IPS e.max CAD™) were milled in the CEREC 3™; Partially Digital (PD), where a polieter impression of the master model was poured with type IV gypsum, with the Bluecam™ scanning the working model and the 12 full crown coverages (IPS e.max CAD™) being milled by the CEREC 3™. The replica technique, where the light body silicone simulate the cement, was used to evaluate the fit of the crowns. Two cross sectioned replicas per crown were obtained, generating images of the bucco-palatal and mesio-distal interfaces under 50x magnification. Four interface areas were choosen to the evaluation: Marginal Opening (AM); Chamfer (CH), Axial Wall (PA); and Occlusal Wall (PO). The hole interface area of each image was evaluated, generating approximately 6.000 points to be rated per interface. Results were statistical analyzed with one-way-Anova and Scheafer's post hoc with a 5% level of significance. All the 3 tested groups showed clinically acceptable mean values for marginal and internal fit. For the areas AM, CH and PO, similar results were found between the 3 groups. For the PA area, TC group showed significantely higher values than PD and TD groups (p = 0,001). The different workflows, conventional or digitals, used in this study were proven capable to present elegible marginal and internal fit, based on the accepted current values for porcelain full coverage crowns.

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Atualmente, os implantes são utilizados em diversos tipos de tratamento na reabilitação oral. Para manutenção da osseointegração, é essencial que o conjunto prótese/implante/osso seja submetido a forças às quais estejam aptos a suportar. Os diferentes tipos de desadaptações das infraestruturas das próteses sobre implantes são fatores que podem contribuir para o aumento das tensões na região peri-implantar. Este estudo teve como objetivo avaliar a influência das desadaptações angulares unilaterais na distribuição de tensões na região periimplantar de pilares tipo UCLA, no momento da pré-carga e carga axial. Infraestruturas de CoCr, confeccionadas utilizando-se pilares tipo UCLA, foram divididas em quatro grupos: Grupo A (adaptado), Grupo B, Grupo C e Grupo D (50, 100 e 200 μm de desadaptação unilateral angular por vestibular, respectivamente). Cada grupo foi representado por quatro infraestruturas (n=4). Quatro implantes (4.1mm/15mm) foram posicionados em uma matriz metálica, onde posteriormente foi vazado o poliuretano (PU), com função de simular o tecido ósseo. Quatro extensômetros (strain gauges) foram posicionados na região vestibular, distal, lingual e mesial de cada implante, para aferir a quantidade de deformação; cada grupo foi posicionado em seu respectivo implante. Foram realizados dois testes: o teste de pré-carga com um torque de 32Ncm e o teste de carga com uma força axial estática de 300N. Cada infraestrutura foi sujeita aos dois testes, por cinco vezes. Para análise estatística dos dados, foram utilizados ANOVA (dois critérios) e o teste de Tukey (p<0,05). Os resultados mostraram que os grupos A e B tiveram menos deformação da região peri-implantar em ambos os testes, quando comparados aos grupos C e D. A estatística também mostrou que o Grupo A apresentou melhor distribuição de tensões em sua região, peri-implantar quando comparado aos outros três grupos (p<0,05). Como conclusões, este estudo mostrou que as desadaptações influem...

Nowadays implants are used in several kinds of oral rehabilitation treatments. For the osseointegration maintenance it is important that crow/implant/bone are subjected to forces which are able to withstand. Different kinds of misfit on the crown frameworks are factors that could lead to an increase of strain around the implanted bone. This study aimed to evaluate the influence of the unilateral angular misfit in frameworks made of UCLA on the peri-implant strain distribution, subjected to preload and axial load. Frameworks made of chrome-cobalt were fabricated on UCLA abutments and divided in 4 groups: Group A (no misfit), Group B, Group C, Group D (50, 100, and 200 of unilateral angular misfit by buccal side, respectively). Each group was represented for 4 frameworks (n=4). Four implants (4.1mm/15mm) were positioned in a metallic matrix which was subsequently poured the polyurethane (PU) to simulate the bone. Four strain gauges were positioned on the buccal, distal, lingual and mesial sides of each implant to assess the amount of strain, each group was connected on its respectively implant. It was performed 2 tests: the preload test with a 32Ncm torque and the load test by applying an axial force of 300N. Each framework was subjected to the both test five times. To the statistics analysis ANOVA (2 ways) and Turkeys test were performed. The results showed that the Groups A and B presented less deformation when compared to Groups C and D. The statistics also showed that the Group A presented better distribution of strain on its peri-implant bone when compared to the other three groups (p<0,05). In conclusion this study showed that misfit had influence on the strain distribution on the peri-implant bone and that strain increased on the Groups C and D which presented higher levels of misfit.

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Atualmente, os implantes são utilizados em diversos tipos de tratamento na reabilitação oral. Para manutenção da osseointegração, é essencial que o conjunto prótese/implante/osso seja submetido a forças às quais estejam aptos a suportar. Os diferentes tipos de desadaptações das infraestruturas das próteses sobre implantes são fatores que podem contribuir para o aumento das tensões na região peri-implantar. Este estudo teve como objetivo avaliar a influência das desadaptações angulares unilaterais na distribuição de tensões na região periimplantar de pilares tipo UCLA, no momento da pré-carga e carga axial. Infraestruturas de CoCr, confeccionadas utilizando-se pilares tipo UCLA, foram divididas em quatro grupos: Grupo A (adaptado), Grupo B, Grupo C e Grupo D (50, 100 e 200 μm de desadaptação unilateral angular por vestibular, respectivamente). Cada grupo foi representado por quatro infraestruturas (n=4). Quatro implantes (4.1mm/15mm) foram posicionados em uma matriz metálica, onde posteriormente foi vazado o poliuretano (PU), com função de simular o tecido ósseo. Quatro extensômetros (strain gauges) foram posicionados na região vestibular, distal, lingual e mesial de cada implante, para aferir a quantidade de deformação; cada grupo foi posicionado em seu respectivo implante. Foram realizados dois testes: o teste de pré-carga com um torque de 32Ncm e o teste de carga com uma força axial estática de 300N. Cada infraestrutura foi sujeita aos dois testes, por cinco vezes. Para análise estatística dos dados, foram utilizados ANOVA (dois critérios) e o teste de Tukey (p<0,05). Os resultados mostraram que os grupos A e B tiveram menos deformação da região peri-implantar em ambos os testes, quando comparados aos grupos C e D. A estatística também mostrou que o Grupo A apresentou melhor distribuição de tensões em sua região, peri-implantar quando comparado aos outros três grupos (p<0,05). Como conclusões, este estudo mostrou que as desadaptações influem...

Nowadays implants are used in several kinds of oral rehabilitation treatments. For the osseointegration maintenance it is important that crow/implant/bone are subjected to forces which are able to withstand. Different kinds of misfit on the crown frameworks are factors that could lead to an increase of strain around the implanted bone. This study aimed to evaluate the influence of the unilateral angular misfit in frameworks made of UCLA on the peri-implant strain distribution, subjected to preload and axial load. Frameworks made of chrome-cobalt were fabricated on UCLA abutments and divided in 4 groups: Group A (no misfit), Group B, Group C, Group D (50, 100, and 200 of unilateral angular misfit by buccal side, respectively). Each group was represented for 4 frameworks (n=4). Four implants (4.1mm/15mm) were positioned in a metallic matrix which was subsequently poured the polyurethane (PU) to simulate the bone. Four strain gauges were positioned on the buccal, distal, lingual and mesial sides of each implant to assess the amount of strain, each group was connected on its respectively implant. It was performed 2 tests: the preload test with a 32Ncm torque and the load test by applying an axial force of 300N. Each framework was subjected to the both test five times. To the statistics analysis ANOVA (2 ways) and Turkeys test were performed. The results showed that the Groups A and B presented less deformation when compared to Groups C and D. The statistics also showed that the Group A presented better distribution of strain on its peri-implant bone when compared to the other three groups (p<0,05). In conclusion this study showed that misfit had influence on the strain distribution on the peri-implant bone and that strain increased on the Groups C and D which presented higher levels of misfit.

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El objetivo de esta investigación fue determinar la condición periodontal en prótesis fijas singulares (PFS) realizadas en la clínica odontológica Integral del Adulto I y II de la Universidad Mayor de Temuco entre los años 2007 y 2009. Se evaluaron 73 PFS mediante un examen clínico, realizadas en 41 pacientes. Se analizaron las variables: edad, sexo, pieza dentaria, año de atención, año académico en que se realizaron las PFS, material de las prótesis fijas; los parámetros periodontales evaluados en este estudio fueron edema y eritema, sangramiento y recesión gingival. La frecuencia de edema y eritema fue de 81 por ciento, el sangramiento lo encontramos en un 77 por ciento y la recesión gingival en un 27 por ciento. Las mujeres presentaron mayores problemas de los tejidos periodontales con un 85 por ciento de edema y eritema y un 81 por ciento de sangramiento. Las PFS realizadas en el 4to año académico presentaron un 55 por ciento de recesión gingival y las realizadas en el 5to año mostraron un 17 por ciento. En relación al año de atención en el que se realizaron las rehabilitaciones, las PFS realizadas en el año 2007 presentaron un 100 por ciento de inflamación, mientras que en los otros años (2008 y 2009) las PFS presentaron menos daño a nivel gingival. Las piezas más afectadas según la ubicación en la boca, fueron las posteriores con un 84 por ciento de edema y eritema. Respecto al material, las PFS que presentaron más problemas de edema y eritema fueron las de metal cerámica con un 82 por ciento. Del total de los 41 pacientes observados, la mayoría estaban satisfechos con su rehabilitación. Finalmente se puede concluir que no existió evidencia estadísticamente significativa para concluir que existe una asociación entre las variables edad, sexo, año de atención y las variables edema y eritema, sangramiento y recesión gingival. En cambio, si se encontró evidencia estadísticamente significativa entre el cuarto y quinto año académico/ durante el tiempo/...

The aim of this study was to determine the periodontal condition in fixed single prostheses made at Integral Adult Dental Clinic I and II of the Universidad Mayor in Temuco, between the years 2007 and 2009. Seventy-three fixed single prostheses were evaluated by clinical examination, made in 41 patients. Variables were analyzed: age, sex, tooth, year of care, year in which the fixed single prostheses were made, fixed single prostheses material; periodontal parameters evaluated in this study were edema and erythema, bleeding and gingival recession. Edema and erythema's frequency were 81 percent, bleeding in 77 percent and gingival recession in 27 percent. Women presented major problems in periodontal tissues with 85 percent of edema and erythema and 81 percent of bleeding. Fixed single prostheses made in 4th year showed 55 percent of gingival recession and the ones that were made in 5th year showed 17 percent. In relation to the year of care in which the rehabilitations were made, the fixed single prostheses made in 2007 showed 100 percent of inflammation, while in the other years (2008 and 2009) the fixed single prostheses showed less damage at gingival level. The most affected teeth according to the location in the mouth were the back ones with 84 percent of edema and erythema. Regarding material, the fixed single prostheses that showed more edema and erythema problems were the metal-ceramics with 82 percent. Of the total of the 41 patients observed, the majority was satisfied with their rehabilitation. Finally we can conclude that there was no statistically significant evidence to conclude that there is an association between the variables age, sex, year of care and the variables edema and erythema, bleeding and gingival recession. In contrast, if found statistically significant evidence between the 4th and 5th year/ during the time/ years in which the fixed single prostheses and the gingival recession were made.

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