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A similar number used the TLD for implant placement and abutment screw tightening. Screw-tightening protocols varied. Preload was not understood by the majority of those surveyed.
Dentistry does not appear to adhere to the protocols and standards recommended by other industries that also rely on screw-fastening mechanisms and TLDs. Further education and training appears to be warranted in this area of implant dentistry to reduce the risks of screw-associated complications.
Dentistry does not appear to adhere to the protocols and standards recommended by other industries that also rely on screw-fastening mechanisms and TLDs. Further education and training appears to be warranted in this area of implant dentistry to reduce the risks of screw-associated complications.
The purpose of this study was to evaluate in vitro the accuracy of different splinting techniques using transfers combined with different tray types.
The research group fabricated a maxillary master cast with four implants and a passive metallic bar on this master cast. For the impression techniques, 48 casts were used with six different impression techniques (1) metal tray with resin splinted transfers, (2) metal tray with metal and resin splinted transfers, (3) plastic tray with resin splinted transfers, (4) plastic tray with metal and resin splinted transfers, (5) multifunctional guide with resin splinted transfers, and (6) multifunctional guide with metal and resin splinted transfers (n = 8) using polyvinyl siloxane impression material. This study used a passive metallic bar to measure the malalignment between the framework and the analogs (A, B, C, and D) in 2D and 3D. The master and experimental casts were scanned with a contact scanner to compare the accuracy in 3D impression techniques. Discrepancfunctional guide, respectively, in the z-axis and the combination between the xz-axes. The bonding technique of the transfers with metal and acrylic resin presents better results in the 3D analysis for the multifunctional guide impressions.
The evaluation methods for the accuracy impression technique presented different results between them. There was no difference in vertical malalignments (2D), but in 3D, the bonding with metal and acrylic resin presented better results than the bond with only acrylic resin when using the plastic tray and multifunctional guide, respectively, in the z-axis and the combination between the xz-axes. The bonding technique of the transfers with metal and acrylic resin presents better results in the 3D analysis for the multifunctional guide impressions.
Clinical cases have shown that pterygoid implants are a successful alternative solution for the rehabilitation of atrophic posterior maxillae; however, little research on the biomechanical behavior has been produced. This study created 3D models of pterygoid implant-supported prostheses and compared the stress and strain distributions in the pterygoid implants and surrounding bone using finite element analysis.
Three-dimensional models of a standardized human skull, pterygoid implants, and conventional dental implants were created using Simpleware, based on microcomputed tomography (micro-CT) and CBCT images. Six constructs with varying implant positions and numbers were designed to simulate various clinical scenarios for patients with complete maxillary edentulism. Finite element volume meshes were created and exported to ABAQUS, where the modulus of elasticity and Poisson ratio were assigned for each respective structure. Two load scenarios were simulated with conditions as follows (1) 150-N axial loadiAdditional concern should be placed on the crestal bone of the premolar region and the implant-abutment connections of the pterygoid implants, since these locations had the highest recorded values.
Pterygoid implants decreased the stress and strain level in the surrounding bone for all cases studied. Additional concern should be placed on the crestal bone of the premolar region and the implant-abutment connections of the pterygoid implants, since these locations had the highest recorded values.
To assess the effects of grade IV titanium ultrasonic tip instrumentation on different grade IV titanium implant surfaces and compare the decontamination of different implant surfaces using chlorhexidine, blue laser, or ozone.
Profilometry and energy-dispersive x-ray spectroscopy (EDS) analyses were performed on smooth, laser-micropatterned, and sandblasted grade IV titanium sample disks before (t
) and after (t
) ultrasonic instrumentation with an ultrasonic grade IV titanium tip. Samples were also incubated with a Streptococcus sanguinis culture. Each surface type was then treated with chlorhexidine, blue laser, or ozone (three test groups + control group). Scanning electron microscopy (SEM) images were taken after bacterial growth and after decontamination.
After ultrasonic instrumentation, surface roughness (R
) decreased on sandblasted and micropatterned surfaces, whereas it remained substantially unvaried on the smooth surface. SEM images revealed that the laser-micropatterned structure remained substantially unvaried after instrumentation. EDS revealed a minimal quantity of carbon and iron, found in the laser-treated and sandblasted group at t0. A minimal quantity of aluminum and oxygen was found on the sandblasted surface at t
and t
. Ozone therapy achieved the highest decontaminating effect, regardless of implant surface topography.
Among the alternative therapies to ultrasonic instrumentation with titanium tips, ozone appears to be effective regardless of the type of implant surface; it can be used for the decontamination treatment of implants without altering the surface structure.
Among the alternative therapies to ultrasonic instrumentation with titanium tips, ozone appears to be effective regardless of the type of implant surface; it can be used for the decontamination treatment of implants without altering the surface structure.
To review the evidence from the clinical outcomes of immediately loaded implants with fixed prostheses in edentulous maxillae.
An electronic search was performed in PubMed/MEDLINE, Embase, and Cochrane to identify studies investigating the outcome of implants subjected to immediate loading with fixed dental prostheses in edentulous maxillae. Only clinical studies with more than 10 patients and a mean follow-up time of more than 12 months were included. Meta-analysis was utilized to compare the clinical outcomes between immediately loaded implants and conventionally loaded implants. For immediately loaded implants, a cumulative implant survival rate (ISR) was weighted by the duration of follow-up and number of implants. The weighted marginal bone loss (MBL) was also assessed.
A total of 33 studies (16 retrospective studies and 17 prospective studies) were included, which involved 2,635 patients and 12,480 implants. Meta-analysis did not reveal a significant difference of ISR or MBL between the two loading groups. For immediately loaded implants, the weighted cumulative ISR was 95.53% (median 97.50%) with a mean follow-up of 46.07 months (SD 30.92). Fourteen studies reported on the MBL of implants, and the mean MBL was 1.19 mm (SD 0.88) with a mean period of 57.70 months (SD 32.56). The results should be interpreted with caution due to the lack of randomized controlled trials (RCTs) and the heterogeneity of the data.
Despite the lack of RCTs, immediate implant loading with a fixed prosthesis in the edentulous maxilla seems to be a reliable treatment alternative with a high ISR, when appropriate inclusion/exclusion criteria are followed.
Despite the lack of RCTs, immediate implant loading with a fixed prosthesis in the edentulous maxilla seems to be a reliable treatment alternative with a high ISR, when appropriate inclusion/exclusion criteria are followed.
To evaluate the formation of reactive oxygen species in human leukocytes promoted by bone substitutes that are different in origin and morphology used for jawbone tissue regeneration.
This preclinical prospective randomized crossover study involved 10 subjects, from whom venous blood samples were taken. Leukocytes were separated and standardized. Sixty experimental samples consisted of leukocytes incubated with allogeneic, xenogeneic, or alloplastic bone substitutes at different bone weights (12.5 and 25 mg). The control samples consisted only of incubated leukocytes. Reactive oxygen species were quantitatively determined with the fluorimetric method. Statistical analysis was carried out using SPSS 23 software.
The highest average reactive oxygen species values were obtained in the allogeneic bone substitute group (P < .05), while the xenogeneic bone substitute group and control group presented equal reactive oxygen species formation rates (P > .05). A proportional difference (P < .05) of reactive oxygen species emission was obtained between different masses of bone substitute in the samples.
Allogeneic and alloplastic bone substitutes affect leukocytes and promote reactive oxygen species emission. Xenogeneic bone substitute presents no leukocyte stimulation and maintains anti-inflammatory conditions. Larger bone substitute mass provokes greater oxidative stress.
Allogeneic and alloplastic bone substitutes affect leukocytes and promote reactive oxygen species emission. Xenogeneic bone substitute presents no leukocyte stimulation and maintains anti-inflammatory conditions. Larger bone substitute mass provokes greater oxidative stress.
To evaluate the abutment removal torque and the morphologic aspects of wear in frictional Morse taper connections after axial loading with or without biofilm immersion.
Thirty sets of Morse taper implants and prosthetic abutments were divided into six groups based on the number of mechanical loading cycles and immersion in biofilm derived from human saliva without load, without biofilm; without load, with biofilm; 100,000 cycles of load, without biofilm; 100,000 cycles of load, with biofilm; 500,000 cycles of load, without biofilm; and 500,000 cycles of load, with biofilm. Mechanical loading was applied at a force of 80 ± 15 N with a frequency of 2 Hz for 100,000 or 500,000 cycles. After removal torque evaluation, the internal surface of the implants was evaluated by scanning electron microscopy and optical profilometer. The results were statistically analyzed at a significance level of P = .05.
Overall, the removal torque increased for samples submitted to loading (100,000 cycles of load, without biofi connections, although more studies are recommended to support this affirmation. Oral biofilm did not interfere with the presence of wear areas along the internal surface of Morse taper implants but increased the roughness values.
Cyclic mechanical load on the frictional implant-abutment connection of Morse taper implants increased the removal torque of abutments. The findings of this research suggest that the presence of biofilm can potentially increase the removal torque in frictional Morse taper connections, although more studies are recommended to support this affirmation. Oral biofilm did not interfere with the presence of wear areas along the internal surface of Morse taper implants but increased the roughness values.
