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This study aimed to assess the effects of splinting in 3-unit implant-supported prostheses with varying the splinting factor, length of the implant, and the diameter of the 1°molar (1°M) implant on cortical bone tissue (CBT). Twelve 3D models were simulated, which represented the posterior maxillary with 3 implants, supporting 3-unit FDP varying the splinting factor (single-unit crowns, splinted crowns straight-line and offset implant configuration [OIC]), length of the implant (7mm and 8,5mm), and the diameter of the 1°M (Ø4 mm and Ø5 mm). The CBT was analyzed by maximum principal stress and microstrain maps. The increase in implant diameter improved the biomechanical behavior of rehabilitation. The increase of the implant diameter in the 1°M associated with OIC generated the best biomechanical behavior for CBT. The splinting was effective in decreasing stress and microstrain, mainly when associated with OIC and implant diameter of Ø5 in the 1°M. The effect of increasing the diameter of the implant referring to the 1°M for single-unit crowns was more effective than the effect of the splinting of implants with Ø4 mm in straight-line. The diameter and splinting factors showed to be more important than implant length to reduce the stress and microstrain on CBT.

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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.

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No consensus has been reached regarding the best occlusal scheme for making complete dentures. Thus, the purpose of this systematic review was to compare bilateral balanced occlusion (BBO) with other occlusal schemes (canine guidance, lingualised occlusion and zero degree) in complete dentures. The schemes were compared in terms of quality of life/satisfaction and masticatory performance. Two independent reviewers performed a comprehensive search of studies published in or before October 2017 using the PubMed/MEDLINE, Scopus and Cochrane Library databases. The search was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The focused question was: "In conventional complete denture, is BBO better than lingualised occlusion, canine guidance and zero degree in terms of quality of life, patient satisfaction and masticatory performance/muscle activity?" Seventeen studies were selected for analysis. In total, there were 492 patients with a mean age of 64.78 years and a mean follow-up duration of 2.96 months (range: 1-6 months). All studies compared BBO with the other occlusal schemes. Eleven studies evaluated the influence of the occlusal scheme designs on quality of life and satisfaction, and 8 studies evaluated masticatory performance and muscle activity between BBO and the other occlusion schemes. The present systematic review indicated that BBO does not confer better quality of life/satisfaction or masticatory performance and muscle activity. Thus, lingualised occlusion can be considered a predictable occlusal scheme for complete dentures in terms of quality of life/satisfaction and masticatory performance, while canine guidance can be used to reduce muscular activity.

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There is currently no consensus regarding the survival rate of osseointegrated implants in patients with osteoporosis. A systematic review with meta-analysis was performed to evaluate the survival rate of implants in such patients. The PubMed/MEDLINE, Web of Science, Cochrane Library, and SciELO databases were used to identify articles published up to September 2016. The systematic review was performed in accordance with PRISMA/PICO requirements and the risk of bias was assessed (Australian National Health and Medical Research Council scale). The relative risk (RR) of implant failure and mean marginal bone loss were analyzed within a 95% confidence interval (CI). Fifteen studies involving 8859 patients and 29,798 implants were included. The main outcome of the meta-analysis indicated that there was no difference in implant survival rate between patients with and without osteoporosis, either at the implant level (RR 1.39, 95% CI 0.93-2.08; P=0.11) or at the patient level (RR 0.98, 95% CI 0.50-1.89; P=0.94). However, the meta-analysis for the secondary outcome revealed a significant difference in marginal bone loss around implants between patients with and without osteoporosis (0.18mm, 95% CI 0.05-0.30, P=0.005). Data heterogeneity was low. An increase in peri-implant bone loss was observed in the osteoporosis group. Randomized and controlled clinical studies should be conducted to analyze possible biases.

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The aim of this systematic review and meta-analysis was to compare the survival rate of the implants and the peri-implant tissue changes associated with implants inserted in fresh extraction sockets and those inserted in healed sockets. This review has been registered at PROSPERO under the number CRD42016043309. A systematic search was conducted by two reviewers independently in the databases PubMed/MEDLINE, Embase, and the Cochrane Library using different search terms; articles published until November 2016 were searched for. The searches identified 30 eligible studies. A total of 3,049 implants were installed in a total of 1,435 patients with a mean age of 46.68 years and a minimum of 6 months of follow-up. The survival rate of delayed implants (98.38%) was significantly greater than immediate implants (95.21%) (p=.001). For the marginal bone loss (p=.32), implant stability quotients values (p=.44), and pocket probing depth (p=.94) there was no significant difference between the analysed groups. The immediate implants placed in fresh sockets should be performed with caution because of the significantly lower survival rates than delayed implants inserted in healed sockets.

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This systematic review evaluated the effect on bone formation and implant survival of combining platelet-rich plasma (PRP) with bone grafts in maxillary augmentation. A comprehensive review of articles listed in the PubMed/MEDLINE, Embase, and Cochrane Library databases covering the period January 2000 to January 2015 was performed. The meta-analysis was based on bone formation for which the mean difference (MD, in millimetres) was calculated. Implant survival was assessed as a dichotomous outcome and evaluated using the risk ratio (RR) with 95% confidence interval (CI). The search identified 3303 references. After inclusion and exclusion criteria were applied, 17 studies were selected for qualitative analysis and 13 for quantitative analysis. A total of 369 patients (mean age 51.67 years) and 621 maxillary sinus augmentations were evaluated. After the data analysis, additional analyses were performed of the implant stability quotient, marginal bone loss, and alveolar bone height measured by MD. The results showed no significant difference in implant stability (P=0.32, MD 1.00, 95% CI -0.98 to 2.98), marginal bone loss (P=0.31, MD 0.06, 95% CI -0.05 to 0.16), alveolar bone height (P=0.10, MD -0.72, 95% CI -1.59 to 0.14), implant survival (P=0.22, RR 1.95, 95% CI 0.67-5.69), or bone formation (P=0.81, MD -0.63, 95% CI -5.91 to 4.65). In conclusion, the meta-analysis indicates no influence of PRP with bone graft on bone formation and implant survival in maxillary sinus augmentation.

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The retaining screw of the implant-supported dental prosthesis is the weakest point of the crown/implant system. Furthermore, crown height is another important factor that may increase the lever arm. Therefore, the aim of this study was to assess the stress distribution in implant prosthetic screws with different heights of the clinical crown of the prosthesis using the method of three-dimensional finite element analysis. Three models were created with implants (3.75 mm × 10 mm) and crowns (heights of 10, 12.5 and 15 mm). The results were visualised by means of von Mises stress maps that increased the crown heights. The screw structure exhibited higher levels of stresses in the oblique load. The oblique loading resulted in higher stress concentration when compared with the axial loading. It is concluded that the increase of the crown was damaging to the stress distribution on the screw, mainly in oblique loading.

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