The aim of this study was to evaluate the indirect/closed maxillary floor elevation technique for the insertion of osseointegrated implants to support fixed prostheses clinically. Thirty-one patients (19 female, 12 male) with a mean age of 62 +/- 9 years were selected for this study. All patients needed implants in the posterior maxillary region to support osseointegrated prosthesis. Forty-seven implants were inserted using the indirect/closed sinus floor elevation method, and another 31 implants were placed in the same individuals as intra-individual control. No augmentation material was used along with implantation. The mean bone height before sinus lift was 9.78 +/- 1.68 mm (minimum 5.6 mm), and for controls it was 15.62 +/- 3.44 mm. The average length of the implants used was 12.00 +/- 1.70 mm, whereas for controls it was 13.39 +/- 1.60 mm. The patients were recalled for periodic checkups every 6 months, and the radiographic controls were made every 12 months. One control fixture failed after uncovering; 77 implants were loaded, and 5 of them failed (2 controls and 3 of the sinus lift group) between 3 and 59 months following loading. One hundred nineteen months after surgery (112 months following loading), the censored survival rate (Kaplan-Meier) was 93.6% for sinus lift implants and 90.3% for controls. The crestal bone level changes were not significant either before loading or after loading for both sinus lift and control implants. None of the remaining implants showed any signs of mobility or peri-implant disease, and none of the patients exhibited sinus problems during the entire observation period.
INTRODUCTION:A direct link was found between surface roughness, the accumulation of plaque and the adherence of microorganisms concerning acrylic resins. However, the surface properties of the new thermoplastic materials remain questionable especially after using the conventional finishing and polishing techniques. Studying surface properties of each material makes the recommendation of the proper techniques easier. OBJECTIVES: This in vitro study intended to compare three types of denture base materials in regarding to the effect of different polishing techniques on their surface roughness. MATERIALS AND METHODS: 36 specimens were incorporated in this study. 12 specimens were in each group. 3 groups were formed: Group A: Heat cured Polymethylmethacrylate (PMMA). Group B: Thermoplastic Polyamides. Group C: Thermoplastic Acetal. Dimensions of specimens were (20×20×3 mm) with projection at the side. Statistical analysis was carried out using two way analysis of variance (ANOVA). Statistical significance was defined at P≤0.05. RESULTS: Technique no. 1 showed a high significant value in compared to technique no.2 for polishing the tested materials. CONCLUSIONS: PMMA was the highest affected group followed by thermoplastic acetal and the last affected group was thermoplastic polyamide. Prepolishing rubberizing with rubber bur improves the polishing procedure. RESULTS: Remarkable improvement in the histology and the ultrastructure of the alveolar bone of rats in Group III was observed. Moreover, hematological values revealed significant decrease in the inflammatory condition of rats with induced RA after fish oil treatment. CONCLUSIONS: Rheumatoid arthritis is an important risk factor for alveolar bone loss. The treatment of the RA induced rats with fish oil not only prevented the alveolar bone resorption and stimulated new bone formation, but also reduced relatively the level of rheumatoid factor in the blood.
Objective: In the present study, the 3D finite element method was used to investigate the effect of crown material on stress distribution in the bone surrounding immediately loaded single dental. Materials & Methods: A 3D Finite Element model of mandibular first premolar was constructed to evaluate the performance of seven crown materials with different degree of stiffness (Porcelain, zirconium, Porcelain fused to gold, pure titanium, titanium alloy, Poly methyl methacrylate, and Polyether ether ketone PEEK). The model was constructed using Solid Works version 2010 software. The model simulated also a cement layer between the implant abutment and the crown (Virolink II, Vivadent). An axial static occlusal force of 200 N was applied to eight points in each functional cusp. The three-dimensional (3D) FE model was analyzed by ABAQUS/CAE version 6.10 software. Results: The results of this study indicated that among all crown materials the maximum von Mises stress values was observed in porcelain crown design (345.390 MPa).The highest von Mises stresses were found in the abutments for all models. In implants, the greatest stress was concentrated on the cervical region. PMMA and PEEK crown designs transferred less stress to abutment and screw. In all models, von Mises stresses increased in the coronal third of cortical bone in which the maximum von Mises stresses observed in the implantcortical interface. Conclusions: Using more rigid material for the superstructure of an implant supports prosthesis did not have any effect on the stress values and stress distribution at the bone tissue surrounding implant. However, in the abutment, cement and crown structure, stress distributions and localizations were affected by the material's rigidity. More clinical studies are needed to evaluate the survival rate of these materials.
Objective: To compare accuracy of surgical guided implant produced by intraoral scanner and desktop scanner in partially edentulous patients. Material and methods:Ten individuals with partial dentures were chosen for implant insertion. Eight bilateral instances and two unliteral cases totaling 42 implants were implanted in 4 men and 6 females, with a mean age of 47 years (42-55 years) included. Patients were split into two equal groups at random (n = 21 each): group one Surgical guide manufactured using intra oral digital impression. while group two Surgical guide manufactured using model cast scanning by desktop scanner. a pre cone beam CT scan was done and post CBCT was done after implant placement with the same parameters of pre CBCT. Superimposition of CBCT scans was made. The linear and angular deviations of placed implants were measured. Results:The mean 3D angle, platform, apical, and vertical deviations in the intraoral scan group were 2.5°, 0.7 mm, 1.1 mm, and 0.6 mm, respectively. While the average 3D angular, platform, apical, and vertical deviations for the desktop scanner group were, respectively, 2.6°, 0.1mm, 1.1mm, and 1.1mm. Conclusion:both scanning protocols have comparable effect on apical , coronal , vertical and angular deviations of placed implants, although intraoral scanner shows less vertical deviation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.