Search

Purpose: To investigate how well an implant stability quotient (ISQ) represents resonance frequency. Materials and Methods: Benchtop experiments on standardized samples that replicated a mandibular premolar site were conducted to correlate an ISQ value and a resonance frequency to synthetic bone density and an incremental insertion torque; then, a frequency spectrum analysis was performed to check the validity of the resonance frequency analysis (RFA). Brånemark Mk III implants (4 × 11.5 mm; Nobel Biocare) were placed in Sawbones test models of five different densities (40, 30, 40/20, 20, and 15 PCF). An incremental insertion torque was recorded during implant placement. To perform stability measurements, the test models were partially clamped in a vise (unclamped volume: 10 × 20 × 34 mm). A MulTipeg (Integration Diagnostics) was attached to the implants, and a Penguin (Integration Diagnostics) RFA measured ISQ. Simultaneously, the MulTipeg motion was monitored via a laser Doppler vibrometer and processed by a spectrum analyzer to obtain the resonance frequency. Tightness of the clamp was adjusted to vary the resonance frequency. A statistical analysis produced a linear correlation coefficient (R) among the measured ISQ, resonance frequency, and incremental insertion torque. Results: The resonance frequency had high correlation to the incremental insertion torque (R = 0.978), confirming the validity of using RFA for this study. Measured ISQ data were scattered and had low correlation to the resonance frequency (R = 0.214) and the incremental insertion torque (R = 0.386). The spectrum analysis revealed the simultaneous presence of multiple resonance frequencies. Conclusions: For the designed benchtop tests, resonance frequency does indicate implant stability in view of Sawbones density and incremental insertion torque. However, ISQ measurements do not correlate to the resonance frequency and may not reflect the stability when multiple resonance frequencies are present simultaneously. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the clinical and radiographic results of simultaneous implant placement using transcrestal sinus floor elevation (TSFE) with and without enamel matrix derivative (EMD) application. Materials and Methods: Twenty-four patients were randomly assigned into two groups: The EMD+TSFE group (n = 13 patients, 20 implants) received TSFE with EMD application, and the TSFE group (n = 11 patients, 20 implants) received TSFE without EMD application. The patients were recalled at 3 (T3) and 12 (T12) months postsurgery. The residual bone height (RBH), implant protrusion length (IPL), peri-implant sinus bone level (SBL), endo-sinus bone gain (ESBG), and implant stability (ISQ) were measured. Multivariate regressions were performed for the groups. Results: At T3, the ESBG was 3.72 ± 0.85 mm in the EMD+TSFE group and 3.10 ± 0.05 mm in the TSFE group, and there were statistically significant differences (P < .05). However, there were no statistically significant differences in ESBG at T12 between the groups (P > .05). ISQ values did not show a statistical difference between the groups at T1 and T3, but at T3 in the TSFE+EMD group, there was a statistical increase in the intragroup evaluation compared to the TSFE group. Conclusions: The use of EMD in TSFE procedures is effective in new bone formation at the apical part of the implant during the early healing period, but in the long term, no significant difference was shown between cases in which EMD was or was not used in terms of new bone formation and primary and secondary stabilization. [ABSTRACT FROM AUTHOR]

Purpose: To determine the relationship between bone loss that occurs during the peri-implantitis process and variations in implant stability using resonance frequency analysis (RFA) measurement methods. Materials and Methods: Forty selftapping implants were placed in cow ribs, and study scenarios were established according to the affected implant side and bone loss depth (n = 10 implants per group): Case 1 = bone loss on one side (vestibular); Case 2 = bone loss on two opposite sides (buccal and lingual); Case 3 = bone loss on two adjacent sides (buccal and mesial); and Case 4 = foursided bone loss (circumferential). For each group of 10 implants, first a bone loss of 0 mm was evaluated, then 4-mm defects (simulating 1/3 of bone loss) were created and evaluated, and finally 8-mm defects (simulating 2/3 of bone loss) were created and evaluated. Osteotomy measurements were made with a periodontal probe. For each implant, RFA was measured by the same operator using the Beacon system (Osstell). Results: The initial implant stability quotient (ISQ) values of the 40 implants exceeded 70, reflecting an average of 73 in the buccolingual (VL) and 74.8 in the mesiodistal (MD) directions. ISQ measurements in the 10 implants in which bone dehiscence was performed on the vestibular aspect reflected a decrease in ISQ values as bone loss increased. When generating bone loss in two opposite sides (buccal and lingual), a greater decrease in ISQ values was observed when 2/3 of the implant were affected. The average VL ISQ measurement was less than 70 when at sites with 2/3 of bone loss. Conclusions: When bone loss occurs on only one side of the implant, the ISQ values decrease, but the implant maintains good stability. The same occurs when two opposite sides of the implant are affected, as the unaffected side has the least decrease in ISQ value. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the long-term predictability of simplifying mandibular overdenture treatment using single-stage surgery and immediate prosthetic loading of a single implant to provide a more affordable treatment option. Materials and Methods: A total of 29 patients with a mean age of 68 years with problematic mandibular dentures were treated. A single implant (Brånemark System Mklll TiUnite, Nobel Biocare) was placed into the mandibular midline for primary stability. A ball attachment was placed, and the retentive cap was incorporated into the existing denture. The patients were recalled at 3 and 12 months and at 3, 5, 10, and 15 years. Clinical assessments, radiographs, and resonance frequency analysis were recorded. All complications, failures, maintenance, and reasons for failure to follow-up were noted. Visual analog scale (VAS) questionnaires were used to record patient satisfaction (ANOVA; P < .05). Results: One implant did not achieve sufficient primary stability to be immediately loaded and was treated with a two-stage delayed loading protocol. Of the 28 patients receiving immediately loaded implants, 14 patients were available for follow-up at 15 years. Implant survival remained at 100% throughout the study. Patient satisfaction was high, with a significant increase in all comfort and functional parameters (P values ranged from < .001 to .07) throughout the 15-year period. Conclusions: These 15-year results indicate that immediate loading of a single oxidized surface implant used to retain a mucosa-borne overdenture is a safe, reliable, and cost-effective treatment with high levels of patient satisfaction long term. [ABSTRACT FROM AUTHOR]

Background: The long-term success of dental implants largely depends on achieving primary stability, previously described as crucial to obtaining osseointegration and immediate loading protocol requirements. Implant thread depths seem to be one of the key factors influencing primary stability, particularly in low-density bone. Insertion torque (IT) and resonance frequency analysis (RFA) are considered the most reliable tests to assess primary stability. The aim of this work was to evaluate how different thread depths of commercially available dental implants affect primary stability in low-density D3 bone. Materials and Methods: An in vitro study was carried out between February 2024 and March 2024. Twenty-four dental implants were divided into four groups (six implants each) according to their thread depths (Group A: 4 mm, Group B: 4.5 mm, Group C: 5 mm, Group D: 5.5 mm) and were inserted in D3-type artificial bone blocks. The main outcome variables were the IT and the Implant Stability Quotient (ISQ) measured in four different areas of the implant (buccal, lingual, mesial, and distal) with an Osstel® ISQ reader. Descriptive and inferential analyses of the data were performed, and the significance value was set at 5%. Results: A total of 24 implants were analyzed. The highest IT values were obtained in Group D, with a mean of 54.03 Ncm (standard deviation (SD) = 8.99), while the lowest measurements were observed in Group A (mean = 25.12; SD: 2.96 N.cm). The mean ISQ values were consistently higher in Group D for each analyzed area, with a mean of 70.13 N.cm (SD = 1.12). Conclusions: Taking into consideration the limitations of this in vitro study, greater thread depths seem to increase the primary stability of dental implants placed in soft bone. Furthermore, a positive correlation was observed between all IT and ISQ values, regardless of the thread depth. [ABSTRACT FROM AUTHOR]

In an ultrasonic system, a piezoelectric transducer (PT) is a key component and contains a piezo element inside. In order to design and operate a system that uses a piezo element for its intended purpose, resonance analysis of the piezo element and an equivalent circuit analysis of the output stage of the ultrasonic system generator are required. Due to the characteristics of the equivalent circuit, a piezo element has multiple resonance points. Therefore, the system must be operated at the corresponding frequency by tracking the resonance frequency that suits the purpose of the system. In this study, the mechanical resonance frequency of the piezo element was analyzed and a method for operating the system at the corresponding frequency was studied. In order to operate a piezo element, a voltage-type inverter is used to apply a high-frequency AC (Alternating Current). Then, an L C filter is inserted into the output stage of the inverter, and the piezo element is finally located at the output stage of the L C filter. Therefore, when designing an L C filter, a design is required to optimize the performance of the piezo element. In this paper, we analyzed the resonance of a piezo element and the equivalent circuit of the generator output stage of an ultrasonic system for effective operation of an ultrasonic system. In addition, we proposed a method to estimate the characteristics of the entire mechanical resonance frequency range of a piezo element by using an LSTM (Long Short-Term Memory) model suitable for analyzing the nonlinear characteristics of a piezo element. The study on estimating the mechanical resonance frequency of a piezo element using an LSTM model was verified through MATLAB 2021b simulation and ultrasonic system experiments. [ABSTRACT FROM AUTHOR]

Background and Objectives: The aim of this study was to clinically evaluate the primary and secondary stability of dental implants with different macrodesigns using resonance frequency analysis and to determine whether implant design and length influence implant stability. Materials and methods: This study included 48 healthy patients receiving dental implants, and a pre-implant planning protocol was used, which involved detailed bone analysis, clinical examinations, and Cone beam computed tomography (CBCT) analysis. The implants were of various types and dimensions (Alpha-Bio Tec (Israel), DFI, SPI, and NEO), and the surgical procedures were performed using standard methods. Implant stability was measured using resonance frequency analysis (RFA) immediately after placement and after 3, 6, and 12 months. The total number of implants placed in all patients was 96. Results: The average primary stability value for 10 mm SPI implants placed in the maxilla was 68.2 ± 1.7 Implant Stability Quotient (ISQ) units, while for 10 mm NEO implants, it was 74.0 ± 0.9. The average primary stability value for a 10 mm DFI implant placed in the mandible was 72.8 ± 1.2 ISQ, while for a 10 mm NEO implant placed in the mandible, it was 76.3 ± 0.8 ISQ. Based on the Friedman ANOVA test, the differences in the stability measurements for the 10 mm and 11.5 mm SPI implants and for the 10 mm and 11.5 mm NEO implants in the maxilla on day 0 and after 3, 6, and 12 months were significant at p < 0.05. Similarly, based on the Friedman ANOVA test, the differences in the stability measurements for the 10 mm and 11.5 mm DFI implants and for the 10 mm and 11.5 mm NEO implants in the mandible on day 0 and after 3, 6, and 12 months were significant at p < 0.05 (p = 0.00000). Conclusions: Universal tapered implants of the NEO type stood out as the optimal choice, as they provided statistically significantly higher primary stability in both soft and hard bone types compared to other implants. The implant length did not significantly affect this stability. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to analyze and compare three-dimensional volumetric bone changes and stability of simultaneously placed dental implants following sinus augmentation using deproteinized human demineralized tooth matrix (dpDTM) and deproteinized bovine bone mineral (DBBM). Methods: Twenty-four patients who required lateral maxillary sinus floor augmentation with simultaneous dental implant placement were randomly assigned to receive either dpDTM (n = 12) or DBBM (n = 12). Cone-beam computed tomography and resonance frequency analysis of implant stability were conducted immediately after surgery and 6 months postoperatively. Changes in the graft sinus floor and graft height volumes in the sagittal and coronal views, along with the implant stability quotient (ISQ), were analyzed and compared. Results: Volumetric graft alteration was comparable between dpDTM (120.33 ± 77.48 mm3) and DBBM (108.51 ± 65.15 mm3) (p = 0.690). Reduction in the average graft height was also comparable: dpDTM group ranged from − 0.59 to − 0.93 mm and the DBBM group ranged from − 0.55 to − 0.82 mm (p > 0.05) at most examined levels. However, greater reduction in the mesial-graft height occurred in the dpDTM group (− 1.08 ± 0.70 mm vs. −0.58 ± 0.39 mm, p = 0.04). The ISQ values increased similarly in both groups to reach 70 at 6 months. Conclusion: dpDTM demonstrated comparable stability in graft volume and height during the healing process compared to DBBM and could serve as a viable alternative to DBBM for sinus floor augmentation with simultaneous implant placement. [ABSTRACT FROM AUTHOR]

The aim of this study was to find in the literature data on the relationship between implant surface roughness and implant stability achieved, from the time of placement to three months afterward, to help us to know what type of surface roughness is more favorable to guarantee implant stability and osseointegration. A systematic review was conducted in accordance with the PRISMA 2020 (Preferred Reporting Items for Systematic Review and Meta-analysis) statement, and the protocol was registered on the Open Science Framework. The specific inclusion and exclusion criteria were selected using the PICOS framework. The databases Medline (PubMed), Scopus, the Web of Science and The Cochrane Library were searched up to October 2023. The selection of studies and data extraction were conducted by two independent reviewers. The review included a total of 11 studies. A total of 1331 dental implant placements were identified. Two of the eleven selected studies were on humans in vivo, eight were on animals in vivo, and one was on animals in vitro. A statistically significant correlation between surface roughness and implant stability as measured by resonance frequency analysis (RFA) was not identified in ten of the eleven selected studies. It appears that there is no correlation between primary stability and the degree of implant roughness. However, there appears to be a correlation between the roughness of the implant and the degree of osseointegration, as indicated by bone-implant contact values. This correlation is more closely related to secondary stability. The great methodological variability makes it difficult to compare data and draw conclusions, so it would be desirable to agree on a common methodology to help draw appropriate conclusions from published studies. [ABSTRACT FROM AUTHOR]

Background: The long-term success of dental implants largely depends on achieving primary stability, previously described as crucial to obtaining osseointegration and immediate loading protocol requirements. Implant thread depths seem to be one of the key factors influencing primary stability, particularly in low-density bone. Insertion torque (IT) and resonance frequency analysis (RFA) are considered the most reliable tests to assess primary stability. The aim of this work was to evaluate how different thread depths of commercially available dental implants affect primary stability in low-density D3 bone. Materials and Methods: An in vitro study was carried out between February 2024 and March 2024. Twenty-four dental implants were divided into four groups (six implants each) according to their thread depths (Group A: 4 mm, Group B: 4.5 mm, Group C: 5 mm, Group D: 5.5 mm) and were inserted in D3-type artificial bone blocks. The main outcome variables were the IT and the Implant Stability Quotient (ISQ) measured in four different areas of the implant (buccal, lingual, mesial, and distal) with an Osstel® ISQ reader. Descriptive and inferential analyses of the data were performed, and the significance value was set at 5%. Results: A total of 24 implants were analyzed. The highest IT values were obtained in Group D, with a mean of 54.03 Ncm (standard deviation (SD) = 8.99), while the lowest measurements were observed in Group A (mean = 25.12; SD: 2.96 N.cm). The mean ISQ values were consistently higher in Group D for each analyzed area, with a mean of 70.13 N.cm (SD = 1.12). Conclusions: Taking into consideration the limitations of this in vitro study, greater thread depths seem to increase the primary stability of dental implants placed in soft bone. Furthermore, a positive correlation was observed between all IT and ISQ values, regardless of the thread depth.

Adequate implant primary stability is a key factor to obtain osseointegration and can be measured at insertion by insertion torque (IT) and at different timepoints with resonance frequency analysis (RFA), expressed as an implant stability quotient (ISQ). This retrospective study investigated the correlation between ISQ and IT at implant insertion. All patients who were eligible for this single-cohort retrospective clinical trial were treated with an immediate implant. IT parameters were recorded at implant insertion, and ISQ values were recorded at insertion and at 2-, 4-, and 12-month follow-ups. The study comprised 23 patients who received 32 implants. The mean IT value was 46.87 ± 9.66 Ncm (range: 25 to 65 Ncm), and the mean ISQ value at implant insertion was 71.45 ± 4.24 (range: 63 to 78); these values showed a statistically significant correlation (P < .0001). According to the present data and considering the implant design used in this trial, there is a statistically significant and positive correlation between IT and ISQ values. Thus, ISQ can be used as a reliable method to measure implant stability over time. [ABSTRACT FROM AUTHOR]

Purpose: To compare the stability of short vs standard (ie, regular-length) implants in the edentulous mandible. Materials and Methods: In this prospective clinical study, 20 patients with edentulous mandibles received four implants each--two short implants (4 mm) in the region of the first molar and two standard implants (= 10 mm) in the interforaminal region. Implant stability was assessed using resonance frequency analysis immediately after implant placement and at the day of the abutment connection after 3 months of healing in order to provide an implant stability quotient (ISQ). Results: Implant stability in the two implant groups at placement (ISQ: short 66.2; standard 68.2) and at abutment connection (ISQ: short 74.9; standard 75.7) did not differ substantially or statistically significantly (both P > .05). Findings did not change after statistically controlling for potential confounders such as bone quality and bone crest width. At abutment connection, 95% of the short and 97.5% of the standard implants demonstrated sufficient stability for conventional loading (P > .05). Conclusions: Short dental implants demonstrate similar primary and secondary stability compared to standard implants and seem to be a promising treatment option for rehabilitation of patients with edentulous mandibles. [ABSTRACT FROM AUTHOR]

Purpose: To determine the optimal implant diameter under limited bone width by comparing the effects of implants with different diameters on implant stability, peri-implant bone stability, and osseointegration. In addition, to evaluate the reliability of resonance frequency analysis (RFA) in detecting osseointegration and marginal bone level (MBL). Materials and Methods: Mandibular premolars and first molars of seven beagle dogs were extracted. After 8 weeks, their mandibular models and radiographic information were collected to fabricate implant templates. Implant sites were randomly divided into three groups according to diameter: Ø3.3, Ø4.1, and Ø4.8 mm. Implant stability quotient (ISQ) measurement and radiographic evaluation were performed after surgery (baseline) and at 4, 8, and 12 weeks. Three dogs were euthanized at 4 weeks to observe osteogenesis and implant-tissue interface biology. Four dogs were euthanized at 12 weeks to observe osseointegration. Hard tissue sections were prepared to analyze osteogenesis (fluorescence double labeling) and osseointegration (methylene blue-acid fuchsin staining). Results: At baseline and at 4, 8, and 12 weeks, the ISQ values of Ø4.1- and Ø4.8-mm implants did not differ (P > .05), but both had higher values than the Ø3.3-mm implants (P < .05). The mean marginal bone resorption (MBR) associated with Ø3.3-, Ø4.1-, and Ø4.8-mm implants was 0.65 ± 0.58 mm, 0.37 ± 0.28 mm, and 0.73 ± 0.37 mm, respectively. The buccal MBR of Ø4.8-mm implants was significantly higher than that of Ø4.1-mm implants (P < .05). The bone-to-implant contact (BIC) percentage at 12 weeks did not differ for any group (P > .05). The correlation coefficients between the ISQ and MBL of the Ø3.3-, Ø4.1-, and Ø4.8-mm implants were -0.84 (P < .01), -0.90 (P < .001), and -0.93 (P < .001), respectively, while that between the ISQ and BIC was 0.15 (P > .05). Conclusions: During the early healing stage, the performance of Ø4.1- and Ø4.8-mm implants in terms of implant stability was better than that of Ø3.3-mm implants. Implant diameter may not influence BIC percentage. RFA can be used to evaluate implant stability and MBL but is not suitable to assess the degree of osseointegration. [ABSTRACT FROM AUTHOR]

Purpose: To compare the osseointegration process of the titanium dental implants with five different surface characteristics--sandblasted, sandblasted and acid-etched, hyaluronic acid--coated (HYA), hydroxyapatite-coated (HA), and machined--in an experimental sheep model at 1- and 3-month examinations. Materials and Methods: One hundred sixty dental implants were placed in the left and right tibias of 16 sheep. Five experimental groups were designed. Eight animals (80 implants) were used for biomechanical tests of reverse torque analysis and resonance frequency analysis (RFA). Eight of them (80 implants) were used for the evaluation of bone-to-implant contact (BIC) percentage in histomorphometric analysis. Forty of 80 implants (8 implants for each group) were used at 1-month examinations, and the remaining 40 (8 implants for each group) implants were used at 3-month examinations in the biomechanical test group and histomorphometric examination group, separately. Results: Intergroup analysis at the 3-month followup showed that the increase in the implant stability quotient (ISQ) value was statistically significant for only the HYA group (P < .05). According to ISQ values at 1 and 3 months, group HYA showed statistically higher values at the 1 and 3-month examinations (P < .05). Groups HYA and HA had statistically higher reverse torque values than other groups at the 1-month examination (P < .05). At the 3-month evaluation, the HYA group showed significantly higher reverse torque values compared to other groups (P < .05). The BIC values of the sandblasted and acid-etched, HYA, and HA groups were significantly higher than the sandblasted and machined groups at the 1- and 3-month examinations (P < .05). The BIC value for the HA group showed decreased value at the 3-month examination compared to the 1-month examination (P < .05). Conclusion: The RFA, reverse torque, and histomorphometric analysis at 1- and 3-month examinations show that dental implants coated with HYA may have increased potential for osseointegration compared to dental implants with sandblasted, sandblasted and acid-etched, machined, and HA-coated surfaces. [ABSTRACT FROM AUTHOR]

Purpose: To determine the biologic and biomechanical effects of two implant drilling protocols on the cortical bone around implants subjected to immediate loading. Materials and Methods: A total of 48 implants were inserted into the mandibles of six sheep following one of two drilling protocols: undersized preparation (US; n = 24) and nonundersized preparation (NUS; n = 24). Immediately after implant insertion, an abutment was placed on each implant and 36 implants were subjected to 10 sessions of dynamic vertical loads (1,500 cycles, 1 Hz) of 25 N or 50 N. Insertion torque value (ITV) was recorded at implant installation. Resonance frequency analysis (RFA) was measured at implant insertion and at each loading session. Fluorochrome was administered at day 17, and the animals were euthanized after 5 weeks. The removal torque values (RTVs) were measured, and samples underwent histomorphometric, μCT (microcomputed tomography), and fluorescence image acquisition analyses. The bone volume density (BV/TV), bone-to-implant contact (BIC), bone area fraction occupancy (BAFO), and fluorochrome stained bone surface (MS) were calculated. A linear mixed model analysis was performed, and Pearson paired correlation was calculated. Results: Five implants from the NUS group failed, with a mean ITV of 8.8 Ncm and an RFA value of 57. The mean ITVs for US group and NUS group were 80.5 (± 14) Ncm and 45.9 (± 25) Ncm, respectively (P < .001). No differences were noted in the RFA values from the time of implant insertion until the end of the study. No differences in RTV, BV/TV, BAFO, or MS were observed between the groups. Intense new bone formation took place in the NUS group implants that were subjected to load. Conclusions: Undersized preparation of cortical bone ensured a greater BIC compared to a nonundersized preparation. Moreover, this study demonstrated that immediate loading did not interfere with the osseointegration process, but loading induced intense new bone formation in the NUS group. It is not recommended to immediately load the implants when the clinically perceived primary stability is lower than an ITV of 10 Ncm and an RFA value of 60. [ABSTRACT FROM AUTHOR]

Resonance frequency analysis (RFA) is valuable for assessing implant status. In a previous investigation, acetabular cup fixation was assessed using laser RFA and the pull‐down force was predicted in an in vitro setting. While the pull‐down force alone is sufficient for initial fixation evaluation, it is desirable to evaluate the bone strength of the foundation for subsequent fixation. Diminished bone quality causes micromotion, migration, and protracted osseointegration, consequently elevating susceptibility to periprosthetic fractures and failure of ingrained trabecular bone. Limited research exists on the evaluation of bone mineral density (BMD) around the cup using RFA. For in vivo application of laser RFA, we implemented the sweep pulse excitation method and engineered an innovative laser RFA device having low laser energy and small dimensions. We focused on a specific frequency range (2500–4500 Hz), where the peak frequency was presumed to be influenced by foundational density. Quantitative computed tomography with a phantom was employed to assess periprosthetic BMD. Correlation between the resonance frequency within the designated range and the density around the cup was evaluated both in the laboratory and in vivo using the novel laser RFA device. The Kruskal–Wallis test showed robust correlations in both experiments (laboratory study: R = 0.728, p < 0.001; in vivo study: R = 0.619, p < 0.001). Our laser RFA system can assess the quality of bone surrounding the cup. Laser RFA holds promise in predicting the risk of loosening and might aid in the decision‐making process for additional fixation through screw insertion. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate primary stability of a new dental implant design in low-density bone sites, compare it with another implant design previously studied in the same bone density, and explore possible correlations between primary stability parameters. Materials and Methods: The study was carried out on fresh humid bovine bone classified as type III. The test group consisted of 30 DS Prime Taper implants (PT), and the control group consisted of 30 Astra Tech EV implants (EV). All the implants were inserted according to the protocol provided by the manufacturer. After placement, variable torque work (VTW), peak insertion torque (pIT), and resonance frequency analysis (RFA) were recorded. Results: Mann-Whitney test showed that the mean VTW and pIT were significantly higher in the test group PT compared to the control group EV; furthermore, statistical analysis showed that the mean RFA was slightly higher in the control group EV but without reaching statistical significance. Pearson correlation analysis showed a very strong positive correlation between pIT and VTW values in both groups; furthermore, it showed a positive correlation between pIT and RFA values and between VTW and RFA values again in both groups. Conclusion: The results showed that the novel tapered implants were able to reach good primary stability in low-density bone sites and that this was superior to parallel-walled implants when measured with VTW and pIT. Moreover, a statistically significant correlation was found between the three methods used to measure implant primary stability. [ABSTRACT FROM AUTHOR]

Accurate detection of implant loosening is crucial for early intervention in total hip replacements, but current imaging methods lack sensitivity and specificity. Vibration methods, already successful in dentistry, represent a promising approach. In order to detect loosening of the total hip replacement, excitation and measurement should be performed intracorporeally to minimize the influence of soft tissue on damping of the signals. However, only implants with a single sensor intracorporeally integrated into the implant for detecting vibrations have been presented in the literature. Considering different mode shapes, the sensor's position on the implant is assumed to influence the signals. In the work at hand, the influence of the position of the sensor on the recording of the vibrations on the implant was investigated. For this purpose, a simplified test setup was created with a titanium rod implanted in a cylinder of artificial cancellous bone. Mechanical stimulation via an exciter attached to the rod was recorded by three accelerometers at varying positions along the titanium rod. Three states of peri-implant loosening within the bone stock were simulated by extracting the bone material around the titanium rod, and different markers were analyzed to distinguish between these states of loosening. In addition, a modal analysis was performed using the finite element method to analyze the mode shapes. Distinct differences in the signals recorded by the acceleration sensors within defects highlight the influence of sensor position on mode detection and natural frequencies. Thus, using multiple sensors could be advantageous in accurately detecting all modes and determining the implant loosening state more precisely. [ABSTRACT FROM AUTHOR]

Magnetic resonance imaging (MRI) is widely used in clinical care and medical research. The signal‐to‐noise ratio (SNR) in the measurement affects parameters that determine the diagnostic value of the image, such as the spatial resolution, contrast, and scan time. Surgically implanted radiofrequency coils can increase SNR of subsequent MRI studies of adjacent tissues. The resulting benefits in SNR are, however, balanced by significant risks associated with surgically removing these coils or with leaving them in place permanently. As an alternative, here the authors report classes of implantable inductor–capacitor circuits made entirely of bioresorbable organic and inorganic materials. Engineering choices for the designs of an inductor and a capacitor provide the ability to select the resonant frequency of the devices to meet MRI specifications (e.g., 200 MHz at 4.7 T MRI). Such devices enhance the SNR and improve the associated imaging capabilities. These simple, small bioelectronic systems function over clinically relevant time frames (up to 1 month) at physiological conditions and then disappear completely by natural mechanisms of bioresorption, thereby eliminating the need for surgical extraction. Imaging demonstrations in a nerve phantom and a human cadaver suggest that this technology has broad potential for post‐surgical monitoring/evaluation of recovery processes. [ABSTRACT FROM AUTHOR]

Resonance is commonly used for in situ measurement of the dynamic elastic modulus to evaluate the strength of concrete samples. Many researchers are also exploring the application of this convenient measurement technology for safety monitoring. Nevertheless, the presence of cracks and variations in curing conditions within samples can impact the resonance frequency range, potentially leading to potential inaccuracies in measurements. In order to improve the measurement accuracy of resonance frequency, this study introduces the Generalized S-Transform (GST) algorithm for measuring the dynamic elastic modulus, which utilizes its high time-frequency resolution to scan the power peak-point in non-stationary and transient excitation signals to determine the resonance frequency. For concrete materials with lower consistency, the experimental results verify the high accuracy of this algorithm in measuring resonance frequency compared with Fast Fourier Transform (FFT). This provides a reference for using the algorithm to measure the dynamic elastic modulus in civil engineering applications, such as buildings and bridges. [ABSTRACT FROM AUTHOR]

Objective: Recent years have seen a rise in the usage of dental implants to restore lost teeth. The stability of a dental implant is the main factor in determining its success. Implant stability is influenced by various factors. Several approaches have been employed clinically to evaluate stability at different time intervals. One non-invasive way to assess implant stability is by resonance frequency analysis. Utilizing the resonance frequency analysis method, this study seeks to understand how implant length and diameter affect primary and secondary stability. Methods: The current prospective study was conducted in the Prosthodontics Department of Institute of Dentistry, CMH Lahore Medical College. The duration of the study was six months. A total of 90 implants of sizes 4.5 x 8.5 mm and 4 x 10mm were placed. Resonance frequency measurements were recorded using OsstellTM AB device for primary stability at implant insertion and at 12 weeks for secondary stability. All the measurements were carried out by only one of the researchers to minimize inter-observer bias. Results: The average primary stability was 70.33±6.60, and the average secondary stability was 71.43±5.44. The data was stratified for age, gender, and implant site, and the mean primary and secondary stability of both sizes didn't show any statistically significant differences. Conclusion: Without forfeiting implant stability, both implant sizes (4 x 10mm and 4.5 x 8.5mm) can be used interchangeably, depending on available space and anatomical constraints. [ABSTRACT FROM AUTHOR]

The goal of the current work is to analyse the Zn scaffold porosity effects on its corrosion behavior. Organized porous network structure (OPNS) zinc samples with varying porosity were manufactured by a newly developed rapid tooling approach that combined 3D printing and microwave sintering. The outcomes of the OPNS Zn samples were also compared to the dense zinc sample. For the corrosion analysis, porous and dense zinc samples electrochemical corrosion testing were conducted in SBF electrolyte at 37 °C. The zinc samples morphological study was accessed by scanning electron microscopy (SEM). It was confirmed by the findings of the morphological study that the Zn samples contained randomly distributed micropores and designed or organized macropores. The zinc sample corrosion behavior in SBF was analyzed by potentiodynamic (PD) polarisation and electrochemical impedance spectroscopy (EIS) curves. In addition, an electrical equivalent circuit (EEC) model was developed using the EIS experimental data to establish an understanding of the corrosion behavior of Zn samples. Overall corrosion testing results demonstrate that the diffusion mechanism had an impact on the corrosion mechanism of Zn samples and diffusion mechanism during electrochemical reaction supported by the porosity of the sample. The Zn samples corrosion rate was found to be minimum for the dense sample (0.14 mm y−1), while it was maximum for the highest porosity OPNS Zn sample (0.66 mm y−1). The present study corrosion rate of Zn samples was comparable with the required value for bone implants. [ABSTRACT FROM AUTHOR]

This review discusses the role of diagnostic measures in the lifelong management of periodontal disease and peri‐implant complications. After active treatment, these conditions require regular monitoring of the supporting structures of teeth and dental implants to assess bone and soft tissue health over time. Several clinical measures have been developed for the routine assessment of periodontal and peri‐implant tissues, including periodontal and peri‐implant probing, bleeding on probing, intraoral radiography, biomarker analysis, and microbiological testing. This review highlights the evolution of diagnostic practices, integrating traditional methods with emerging technologies such as resonance frequency analysis and ultrasound imaging to provide a holistic view of peri‐implant health assessment. In addition to objective measurements, patient risk factors are considered. The goals of periodontal and peri‐implant maintenance are to control disease activity and stabilize tissues through supportive care, which includes diagnostic measures at follow‐up visits. This enables clinicians to monitor treatment outcomes, assess health status, and detect recurrence or progression early through routine evaluation, allowing additional interventions, including adjustment of supportive therapy intervals, to further improve and maintain periodontal and peri‐implant stability over time. [ABSTRACT FROM AUTHOR]

In the present study, anatomical assessment of zygomaticofacial foramina (ZFFs) and zygomatic canals communicating with ZFFs were performed using cadaver micro-computed tomography images. It was suggested that all ZFFs were located above the jugale (Ju)-zygomaxillare (Zm) line, which is the reference line connecting the Ju and Zm, and most were located in the zygomatic body area (ZBA). The anteroposterior position of the ZFF in the ZBA was within a middle to posterior region and was most often located slightly posteriorly in males and closer to the middle of the region in females. The mean distance from the Ju-Zm line to the ZFF in the ZBA was 12.36 mm (standard deviation [SD] 1.52 mm) in males and 11.48 mm (SD 1.61 mm) in females. In zygomatic canals communicating with ZFFs, most zygomatic canals were type I canals, communicating from the zygomaticoorbital foramen and harboring the zygomaticofacial nerve, and the others were type II canals, communicating from the zygomaticotemporal foramen and located near the posterior margin of the frontal process. These results provide useful anatomical information for preventing nerve injury during surgical procedures for zygomatic implant treatment. [ABSTRACT FROM AUTHOR]

The evolution of the secondary vortex arrangement around a foil, performing heaving and pitching motion, is numerically examined for a range of phase offsets (90 ° ≤ ϕ ≤ 270°) and reduced frequency (0.32 ≤ S t c ≤ 0.56), at a Reynolds number of 8000. The wake is dominated by two distinct systems of secondary hairpin-like structures. The first vortex system is associated with an elliptic instability, prompted by the paired primary and secondary leading edge vortices (LEV), which remains persistent within the entire range of Stc. However, the growth of the second system is more closely associated with undulations of the primary LEV at S t c ≥ 0.40, which amplifies as it sheds downstream of the trailing edge. The characteristic presence of the first system is directly linked to the growth of the secondary LEV, formed due to the large-scale interactions under localized adverse pressure gradients. These features promote a streamwise flow compression in neighboring regions of the primary LEV. Subsequently, the stability of these wake arrangements is evaluated using dynamic mode decomposition technique, which identifies a neutrally stable state at the fundamental forcing frequency and its harmonics. However, an increase in the modulus of the first three modes, as Stc increases, coincides with stronger three-dimensionality in the wake. The fundamental mode characterizes the roller undulations, while subsequent modes reveal that the two systems of secondary hairpin-like structures are closely associated with the harmonics of forcing frequency. [ABSTRACT FROM AUTHOR]

The peaked cochlear tonotopic response does not show the typical phenomenology of a resonant system. Simulations of a 2 D viscous model show that the position of the peak is determined by the competition between a sharp pressure boost due to the increase in the real part of the wavenumber as the forward wave enters the short-wave region, and a sudden increase in the viscous losses, partly counteracted by the input power provided by the outer hair cells. This viewpoint also explains the peculiar experimental behavior of the cochlear admittance (broadly tuned and almost level-independent) in the peak region. [ABSTRACT FROM AUTHOR]

Objective: To develop tools for predicting velopharyngeal competence (VPC) based on auditory-perceptual assessment and its correlation with objective measures of velopharyngeal orifice area. Design: Methodological study. Participants and Methods: Sixty-two patients with repaired cleft palate, aged 6 to 45 years, underwent aerodynamic evaluation by means of the pressure-flow technique and audiovisual recording of speech samples. Three experienced speech-language pathologists analysed the speech samples by rating the following resonance, visual, and speech variables: hypernasality, audible nasal air emission, nasal turbulence, weak pressure consonants, facial grimacing, active nonoral errors, and overall velopharyngeal competence. The correlation between the perceptual speech variables and velopharyngeal orifice area estimates was analysed with Spearman's correlation coefficient. Two statistical models (discriminant and exploratory) were used to predict VPC based on the orifice area estimates. Sensitivity and specificity analyses were performed to verify the clinical applicability of the models. Results: There was a strong correlation between VPC (based on the orifice area estimates) and each speech variable. Both models showed 88.7% accuracy in predicting VPC. The sensitivity and specificity for the discriminant model were 92.3% and 97.2%, respectively, and 96.2% and 94.4% for the exploratory model. Conclusion: Two predictor models based on ratings of resonance, visual, and speech variables and a simple calculation of a composite variable, SOMA (Eng. "sum"), were developed and found to be efficient in predicting VPC defined by orifice estimates categories based on aerodynamic measurements. Both tools may contribute to the diagnosis of velopharyngeal dysfunction in clinical practice. [ABSTRACT FROM AUTHOR]

This article discusses a modified surgical technique for transcrestal sinus floor elevation, which is used to increase the available bone height for dental implant placement in the maxillary sinus. The technique involves using trephines and osteotomes to create controlled fractures in the maxillary sinus floor, allowing for the placement of dental implants. The article presents a case study in which this technique was successfully used in a patient with extreme maxillary atrophy. The authors highlight the key factors that increase the reliability of the technique and reduce the risk of complications. Overall, this modified technique could be a suitable approach for transcrestal sinus floor elevation in cases of extreme maxillary atrophy with residual bone heights between 2 and 4 mm. [Extracted from the article]

Non-invasive objective implant stability measurements are needed to determine the appropriate timing of prosthetic fitting after implant placement. We compared the early implant stability results obtained using resonance frequency analysis (RFA) and damping capacity analysis (DCA) depending on the implant length and bone density. Total 60, 4.0 mm diameter implants of various lengths (7.3 mm, 10 mm, and 13 mm) were used. In Group I, low-density bone was described using 15 PCF (0.24 g/cm3) polyurethane bone blocks, and in Group II, 30 PCF (0.48 g/cm3) polyurethane bone blocks were used to describe medium density bone. RFA was performed using an Osstell® Beacon+; DCA was performed using Anycheck®. Measurements were repeated five times for each implant. Statistical significance was set at P <0.05. In Group I, bone density and primary implant stability were positively correlated, while implant length and primary implant stability were positively correlated. In Group II, the implant stability quotient (ISQ) and implant stability test (IST) values in did not change significantly above a certain length. Primary implant stability was positively correlated with bone density and improved with increasing implant length at low bone densities. Compared with the Osstell® Beacon+, the simplicity of Anycheck® was easy to use and accessible. [ABSTRACT FROM AUTHOR]

Background/Objective: To ensure that implants are able to support prosthetic rehabilitation, a stable and functional union between the bone and the implant surface is crucial to its stability and success. To increase bone volume and density and excel bone-implant contact, a novel drilling method, called osseodensification (OD), was performed. To assess the effectiveness of the osseodensification drilling protocol versus the conventional surgical technique on implant stability. Methods: Bone Level Tapered Straumann implants were placed side-by-side with both OD and subtractive conventional drilling (SD) in 90 patients from CESPU—Famalicão clinical unit. IT was measured using a manual torque wrench, and the Implant stability quotient (ISQ) value was registered using the Osstell® IDX. Results: According to the multifactorial ANOVA, there were statistically significant differences in the mean IT values due to the arch only (F(1.270) = 4.702, p-value = 0.031 < 0.05). Regarding the length of the implant, there were statistically significant differences in the mean IT in the OD group (p = 0.041), with significantly lower mean IT values for the Regular implants compared to the Long. With respect to the arch, the analyses of the overall ISQ values showed an upward trend in both groups in the maxilla and mandible. High levels of IT also showed high ISQ values, which represent good indicators of primary stability. Conclusions: OD does not have a negative influence on osseointegration compared to conventional subtractive osteotomy. [ABSTRACT FROM AUTHOR]

Harmonic resonance is caused by harmonic source matching resonance frequency and presents the characteristics of decentralization and whole network in modern grids. The current resonance suppression methods mainly focus on reducing the harmonic source, and are suitable for single‐site and small‐scale grids. This paper presents a new method for suppressing parallel resonance at system level. The holistic harmonic resonance is suppressed by reducing the harmonic impedance. In addition, new resonances are prevented by weakening the coupling between resonance and non‐resonance frequencies. The resonance modal analysis and resonance frequency shift (RFS) are employed to optimize harmonic impedance. Simulation results indicate that the capacitance parameter has higher sensitivity and is theoretically more suitable for RFS. Considering the accuracy of modal frequency sensitivity, a variable‐limit genetic algorithm for iteration is proposed. The validity of the proposed method was verified using an IEEE 14‐bus test network. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effect of two different insertion speeds at eight different insertion torque values ranging from 25 to 60 during implantation in a dense polyurethane (PU) D1 bone model on the placement condition and removal torque of dental implants. In this study, 50 pcf single-layer PU plates were used. In the study, a total of 320 implant sockets were divided into two groups, Group 1 (30 rpm) and Group 2 (50 rpm), in terms of insertion speed. Group 1 and Group 2 were divided into eight subgroups with 25, 30, 35, 40, 45, 50, 55 and 60 torques. There were 20 implant sockets in each subgroup. During the implantations, the implant placement condition and removal torque values were assessed. There was a statistically significant difference between the 30 and 50 rpm groups in terms of overall implant placement condition (p < 0.01). It was found that the removal torque values at 50 rpm were statistically significantly higher than those at 30 rpm (p < 0.01). This study showed that in dense D1 bone, the minimum parameters at which all implants could be placed at the bone level were 50 torque at 30 rpm and 40 torque at 50 rpm. [ABSTRACT FROM AUTHOR]

The voltage‐source virtual synchronous generator is a grid‐forming type power electronic control technology and is able to support converters that have the ability of inertial, primary frequency and voltage regulation. Firstly, the authors build the small‐signal model of the voltage‐source virtual synchronous generator and conventional converters, compare and analyse the characteristics of the high‐frequency resonance modes, the results show that the voltage‐source virtual synchronous generator has almost the same high‐frequency resonance characteristics as the conventional converter. Secondly, the different control parameters and power grid strength that affect the high‐frequency resonance characteristic are analysed with eigenvalue, and the mechanism of voltage‐source VSG that caused high‐frequency resonance is derived. The leading factor that causes high‐frequency resonance is power grid strengths, and the authors proposed introducing virtual impedance into the front‐end channel of the current inner loop control strategy to suppress resonance for the voltage‐source virtual synchronous generator based on the theoretical analysis with the small‐signal model and eigenvalue analysis. In addition, the electromagnetic transient simulation model and RT‐LAB controller‐in‐loop platform are built, and the simulation and experiment results indicate the effectiveness of the virtual impedance control strategy. [ABSTRACT FROM AUTHOR]

Background: Osseointegration is critical for the success of dental implants. Surface modifications of dental implants play a crucial role in enhancing osseointegration and implant stability. This in-vitro study aims to evaluate the influence of various surface modifications on dental implant stability. Materials and Methods: Dental implants with different surface modifications were prepared and subjected to in-vitro testing. Surface modifications included sandblasting, acid etching, and plasma spraying. Implant stability was assessed using resonance frequency analysis (RFA) and pull-out tests. Statistical analysis was performed to compare the stability of implants with different surface modifications. Results: The results showed that implants with sandblasted and acid-etched surfaces exhibited significantly higher stability compared with those with only a machined surface. The mean RFA values for sandblasted and acid-etched implants were 75 ± 5 and 80 ± 6, respectively, whereas machined implants recorded a mean RFA value of 60 ± 4. Similarly, pull-out tests demonstrated higher maximum tensile strengths for sandblasted and acid-etched implants compared with machined implants. Conclusion: Surface modifications, such as sandblasting and acid etching, significantly enhance dental implant stability in vitro. These modifications promote better osseointegration, which is crucial for the long-term success of dental implants in clinical practice.

Purpose: To investigate the effects of injectable platelet-rich fibrin (i-PRF) on implant stability. Materials and Methods: A total of 40 implants (BEGO Semados RS/RSX implants, BEGO Implant System) were surgically placed in 15 patients between the ages of 25 and 67 years who had mandibular edentulous areas. After the implant sockets were prepared with the appropriate protocol, i-PRF was applied to the implant surface and socket with the help of a 5-cc sterile syringe in the study group, and implants were placed without i-PRF in the control group. In the research process, the resonance frequency analysis (RFA) method was used to measure implant stability. The implant stability quotient (ISQ) values were determined during the time of the operation and at the first, second, and fourth weeks. Results: The results obtained after the stability measurement periods showed that the decrease in the mean ISQ values in the control group was statistically significant in the first week. Evaluations made in the following weeks were not statistically significant. The study group showed an increase in ISQ values during the measurement periods, and the increases in the second and fourth weeks were statistically significant. Conclusion: I-PRF had positive effects on early implant stability, and i-PRF can be safely used in dental implant surgery and promotes bone healing around dental implants. [ABSTRACT FROM AUTHOR]

Objective: The aim of the study was to assess the long-term prognosis of short implants (5 to 6 mm) placed in the posterior region of the atrophic mandible. Method and materials: The study included 81 patients with severe vertical atrophy of the bone in the posterior region. The patients had 248 short implants (5 to 6 mm) implants placed in the mandibular posterior region and 256 implants with length greater than 10 mm in the mandibular anterior region. Analysis of implant and prosthesis failures, cumulative survival rate, and marginal bone loss was determined at 1 year and 5 years of follow-up (58 ± 7 months). Results: Mean marginal bone loss after 1 year of prosthetic loading was 0.74 mm for short implants and 0.72 mm for implants with length greater than 10 mm; after 5 years of prosthetic loading this was 1.27 mm for short implants and 1.31 mm for implants with length greater than 10 mm. Of 248 short implants (5 to 6 mm), six failed: four due to peri-implantitis and two due to lack of osseointegration (early rejection). Of 256 implants with length greater than 10 mm, five failed: three due to peri-implantitis and two due to lack of osseointegration (early rejection). On average, over the observation period (58 ± 7 months), the 5-year cumulative implant survival rate was 97.8% in short implants, and 98.1% in longer implants; the prosthesis cumulative survival rate was 98.2%. Conclusions: Based on the results, it was concluded that the prognosis of the use of short implants for prosthetics in the posterior resorbed mandible can be considered favorable and reasonable. [ABSTRACT FROM AUTHOR]

Background: The influence of dental implant length and diameter on primary stability in various bone densities is not well understood. Aim: To in vitro study the effect of length and diameter on resonance frequency analysis (RFA), insertion torque (IT) and displacement (DP) measurements of dental implants in different implant site densities. Materials and methods: Dental implants of four different diameters (Ø 3.5, 4.0, 4.5 and 5.0 mm) and three different lengths (7, 11 and 15 mm) (Neoss Ltd, Harrogate, UK) were placed in polyurethane blocks of three different densities (Sawbones Europe AB, Malmö, Sweden). The primary stability was assessed by RFA (ISQ) (Osstell, Osstell AB, Gothenburg, Sweden) and insertion torque measurements (ITmax in N cm) (iChiropo™, Bien‐Air Dental SA, Bienne, Switzerland). In addition, the blocks were mounted in a rig and a lateral force of 25 N cm was applied to the implants and the DP was measured in μm with a micrometer gauge placed on the opposite side of the load transducer. Statistical analyses using linear and quadratic models were applied. Results: Implant length, diameter and block density were found to be significant independent predictors of RFA, ITmax, and DP measurements. Implant length had a strong effect, while the effect of diameter in general was subtle, particularly in the softest block. Conclusions: Implant length affects primary stability more than implant diameter in polyurethane blocks of uniform density along the whole length of the tested implants. [ABSTRACT FROM AUTHOR]

The approach employed for the site preparation of the dental implant is a variable factor that affects the implant's primary stability and its ability to integrate with the surrounding bone. The main objective of this in vitro study is to evaluate the influence of different techniques used to prepare the implant site on the primary stability of the implant in two different densities of artificial bone. Materials and Methods: A total of 150 implant sites were prepared in rigid polyurethane blocks to simulate two distinct bone densities of 15 pounds per cubic foot (PCF) and 30 PCF, with a 1-mm-thick simulated cortex. The implant sites were equally distributed among piezoelectric surgery (PES), traditional drills (TD), and black ruby magnetic mallet inserts (MM). Two methods have been employed to evaluate the implant's primary stability, Osstell and micro-tomography. Results: In the present study, we observed significant variations in the implant stability quotient (ISQ) values. More precisely, our findings indicate that the ISQ values were generally higher for 30 PCF compared to 15 PCF. In terms of the preparation technique, PES exhibited the greatest ISQ values, followed by MM, and finally TD. These findings corresponded for both bone densities of 30 PCF (PES 75.6 ± 1.73, MM 69.8 ± 1.91, and TD 65.8 ± 1.91) and 15 PCF (PES 72.3 ± 1.63, MM 62.4 ± 1.77, and TD 60.6 ± 1.81). By utilizing Micro-CT scans, we were able to determine the ratio of the implant occupation to the preparation site. Furthermore, we could calculate the maximum distance between the implant and the wall of the preparation site. The findings demonstrated that PES had a higher ratio of implant to preparation site occupation, followed by TD, and then the MM, at a bone density of 30 PCF (PES 96 ± 1.95, TD 94 ± 1.88, and MM 90.3 ± 2.11). Nevertheless, there were no statistically significant differences in the occupation ratio among these three approaches in the bone density of 15 PCF (PES 89.6 ± 1.22, TD 90 ± 1.31, and MM 88.4 ± 1.17). Regarding the maximum gap between the implant and the site preparation, the smallest gaps were seen when TD were used, followed by MM, and finally by PES, either in a bone density 15 PCF (PES 318 ± 21, TD 238 ± 17, and MM 301 ± 20 μm) or in a bone density 30 PCF (PES 299 ± 20, TD 221 ± 16, and MM 281 ± 19 μm). A statistical analysis using ANOVA revealed these differences to be significant, with p-values of < 0.05. Conclusion: The outcomes of this study indicate that employing the PES technique and osteo-densification with MM during implant insertion may enhance the primary stability and increase the possibility of early implant loading. [ABSTRACT FROM AUTHOR]

This article discusses a study that used Energy Dispersive X-ray Spectrometry (EDS) to examine the osseointegration of orthodontic mini-implants. The results indicate the presence of newly formed bone on the mini-implants' surfaces, highlighting the importance of osseointegration for successful orthodontic treatment. Another article explores the use of EDS and SEM analysis to study the osseointegration of mini-implants, comparing the elemental composition of unused and used mini-implants with alveolar bone. The study finds evidence of osseointegration and suggests that untreated mini-implants can achieve stability for orthodontic treatment without causing bone damage. Additionally, a document provides a list of references on various aspects of mini-implants, including migration, complications, bone quality, survival rates, and stability. The references also cover factors that can affect mini-implant success, such as bone morphology, surface treatment, size, site, and placement angle, as well as biomaterials, nanotechnology, and wound healing. [Extracted from the article]

This work studies variations of ionospheric total electron content (TEC) during four distinct solar eclipse events over the Ethiopia region. Dual‐frequency global positioning system (GPS) data obtained from UNAVCO over Addis Ababa (9.036°N, 38.76°E) and Bahir Dar (11.6°N, 37.34°E) stations are used to examine the ionospheric variability during two annular solar eclipses on 15 January 2010 and 1 September 2016, a partial solar eclipse on 4 January 2011, and a hybrid solar eclipse (the eclipse path starts out as annular but later changes to total) on 3 November 2013. The results show a significant decrease in TEC values during the occurrence of the solar eclipses. Specifically, the TEC values are reduced to −20% and −10% during the annular eclipse on 15 January 2010, −33% and −38% during the partial solar eclipse on 4 January 2011, −26% and −24% during the annular solar eclipse on 1 September 2016, over the Addis Ababa and Bahir Dar stations, respectively. There is only minimal change in TEC of −8% and −9% at Addis Ababa and Bahir stations, respectively, during the 3 November 2013 solar eclipse even if the obstruction rate is high over the study area. Furthermore, the study shows that the spatial gradient of TEC reduction varies at different locations, which is attributed to the distinct amount of reduction in solar radiation reaching the Earth's surface, resulting in reduced photo‐ionization. Overall, this study provides insightful information about the behavior of the ionospheric TEC during solar eclipses over Ethiopia and emphasizes the use of dual‐frequency GPS data in tracking the variations of the TEC. Key Points: The ionospheric total electron content (TEC) variation due to four solar eclipse events over Ethiopia region was studied for the first timeSolar eclipses lowered the value of TEC up to 38% during various eclipse events over Addis Ababa and Bahir Dar stations in EthiopiaThe rate of reduction of TEC was found to depend on path of eclipse, magnitude, local time, and location of the station [ABSTRACT FROM AUTHOR]

The present study aims to assess the feasibility of implant rehabilitation in kidney-transplanted patients. Patients with kidney transplantation included in periodontal supportive care and at least one year of dialysis with mono- or partial edentulism were eligible for this study. Histomorphometric evaluation of the harvested bone was matched with radiological bone assessment. Implant stability was also monitored with resonance frequency analysis and insertion torque value. Fixed cemented prostheses have been delivered after conventional loading protocol. Supportive periodontal therapy has been administered. Eleven patients (9 males and 2 females) were included. The mean age was 58.1 ± 9.9 years. A total of 17 implants were inserted and analyzed. Mean ITV was 39.3 ± 23.8 Ncm. The mean primary stability (implant stability quotient) at T0 was 71.7 ± 10.5, whereas the mean secondary stability at T1 was 73.0 ± 7.3. The minimum follow-up was 62 months, with a maximum of 84 months (7 years) reached by 4 patients. Fourteen out of 15 implants were in function at a 5-year follow-up (survival rate: 93.3%). Two implants showed peri-implantitis. Seventeen bone samples were collected (13 in the mandible and 4 in the maxilla). The mean percentage of marrow spaces and lamellar bone was 41.6% and 58.4%, respectively. Class 3, according to Misch classification, was found as the mean value of radiological bone density. It can be concluded that implant-supported rehabilitation in kidney-transplanted patients is possible. Adequate periodontal maintenance allows implant rehabilitation in kidney-transplanted patients with long-term sufficient survival rates. [ABSTRACT FROM AUTHOR]

Background: The reduced treatment time of dental implants with immediate loading protocol is an appealing solution for dentists and patients. However, there remains a significant risk of early peri-implant bone response following the placement of immediately loaded implants, and limited information is available regarding loading directions and the associated in vivo characteristics of peri-implant bone during the early stages. This study aimed to investigate the effects of immediate loading directionality on the expression of mechanical sensing protein PIEZO1 and the healing process of peri-implant bone in the early stage. Methods: Thirty-two implants were inserted into the goat iliac crest models with 10 N static lateral immediate loading applied, followed by histological, histomorphological, immunohistochemical, X-ray microscopy and energy dispersive X-ray spectroscopy evaluations conducted after 10 days. Results: From evaluations at the cellular, tissue, and organ levels, it was observed that the expression of mechanical sensing protein PIEZO1 in peri-implant bone was significantly higher in the compressive side compared to the tensile side. This finding coincided with trends observed in interfacial bone extracellular matrix (ECM) contact percentage, bone mass, and new bone formation. Conclusions: This study provides a novel insight into the immediate loading directionality as a potential influence factor for dental implant treatments by demonstrating differential effects on the mechanical sensing protein PIEZO1 expression and related early-stage healing processes of peri-implant bone. Immediate loading directions serve as potential therapeutic influence factors for peri-implant bone during its early healing stage. [ABSTRACT FROM AUTHOR]

Polyether ether ketone (PEEK) has excellent chemical stability, x-ray transmittance, and elastic modulus close to human cortical bone, which can effectively reduce the stress shielding effect. Therefore, PEEK can be used as a commonly used medical bone implant material to repair damaged bones. However, due to its low surface free energy, PEEK has a certain degree of biological inertness. Surface modification methods are urgently needed to improve this problem. Laser surface texturing is expected to improve the biological inertia of PEEK materials. In this study, an ultraviolet laser with a wavelength of 355 nm was used to construct textures on the surface of PEEK materials. By biomimetic design on the surface of PEEK materials, textures similar in depth and width to the surface topography of natural bones were processed. We explore the specific improvement of corrugated texture, single line texture, and orthogonal texture on PEEK material performance, aiming at improving the service performance of PEEK material and creating conditions for better service of PEEK material in vivo. Through the evaluation of PEEK surface contact angle, friction and wear properties, and biocompatibility, the research results show that laser surface texture treatment can improve many service properties of PEEK materials. [ABSTRACT FROM AUTHOR]

This paper presents an analysis of various split-ring resonator (SRR) configurations coupled with coplanar waveguides (CPW). Three distinct resonant structures are presented, namely, the S-shaped split-ring resonator (S-SRR), the conventional split-ring resonator (SRR), and a pair of SRR. Among the examined resonant structures, it is observed that the S-SRR exhibits the smallest electrical size with the corresponding resonant frequency of 1.37 GHz, while the conventional SRR has the largest electrical size with the corresponding resonant frequency of 3.34 GHz. On the other hand, the resonant frequency of a dual SRR is 2.37 GHz. However, the transmission coefficient of a dual SRR is -11.43 dB, which is higher than S-SRR (-10.02 dB) and SRR (-8.18 dB). Furthermore, this study extends the analysis between a square dual SRR and a circular dual SRR with retained area. The square SRR demonstrates a lower resonance frequency (2.23 GHz) relative to its circular counterpart (2.37 GHz). The comparison also shows that the transmission coefficient of the square configuration is -13.88 dB, which is higher than its circular counterpart (-11.43 dB). The realization of a barcode application is achieved by loading multiple S-shaped split ring resonators (S-SRRs) with varying geometric parameters adjacently onto the transmission line. By individually rotating each of these S-SRRs, it becomes possible to alter the notch magnitude, thereby positioning it within a specific designated range corresponding to a particular code. In the case of a configuration involving rotations of (0°, 45°, 90°, 0°, 45°, 90°), this approach results in the creation of a barcode denoted as "100 010 000 100 011 000". This methodology enables the encoding of information in the form of distinctive resonant responses, providing a versatile and compact means of realizing barcode applications. [ABSTRACT FROM AUTHOR]

Here, the results of a phase 1/2 single-arm trial (NCT03744026) assessing the safety and efficacy of blood-brain barrier (BBB) disruption with an implantable ultrasound system in recurrent glioblastoma patients receiving carboplatin are reported. A nine-emitter ultrasound implant was placed at the end of tumor resection replacing the bone flap. After surgery, activation to disrupt the BBB was performed every four weeks either before or after carboplatin infusion. The primary objective of the Phase 1 was to evaluate the safety of escalating numbers of ultrasound emitters using a standard 3 + 3 dose escalation. The primary objective of the Phase 2 was to evaluate the efficacy of BBB opening using magnetic resonance imaging (MRI). The secondary objectives included safety and clinical efficacy. Thirty-three patients received a total of 90 monthly sonications with carboplatin administration and up to nine emitters activated without observed DLT. Grade 3 procedure-related adverse events consisted of pre syncope (n = 3), fatigue (n = 1), wound infection (n = 2), and pain at time of device connection (n = 7). BBB opening endpoint was met with 90% of emitters showing BBB disruption on MRI after sonication. In the 12 patients who received carboplatin just prior to sonication, the progression-free survival was 3.1 months, the 1-year overall survival rate was 58% and median overall survival was 14.0 months from surgery. Recent work indicates that drug delivery to the brain can be improved through disruption of the blood brain barrier using low intensity pulsed ultrasound. Here, the authors report a phase I/II clinical trial investigating the combination of a nine-emitter implantable ultrasound device and carboplatin in patients with recurrent glioblastoma. [ABSTRACT FROM AUTHOR]

Objective: To evaluate patient safety, implants survival and implant stability of the bisphosphonate (zoledronate) as a coating on dental implants in patients requiring oral rehabilitation in the posterior maxilla. Materials and Methods: In this multicenter, double‐blind, randomized controlled study, 62 patients were randomized to receive either zoledronate‐coated or uncoated control implants in the premolar or molar area of the maxilla, using a one stage‐protocol. Due to dropouts and exclusion 49 patients completed the study. The implants were examined by resonance frequency analysis (RFA) using an implant stability quotient (ISQ) scale at the time of insertion, and at 8 weeks, and after 12 weeks prior to prosthetic restoration. Radiographs were taken prior to surgery, directly after insertion, and during the follow‐up at 12 weeks, 6 months, and 1 year to analyze changes in marginal bone levels (MBL). Finally, all complications and adverse effects (AE) were observed and recorded. Results: Out of 62 included patients, 49 patients completed the study. No AE were reported by patients receiving zoledronate‐coated implants. There was no statistically significant difference between the zoledronate‐coated or uncoated implant groups when comparing ISQ levels at insertion and after 12 weeks of healing, the mean of the ISQ values demonstrated a change of 4.64 (95% confidence interval: 15.46; 5.79, p = 0.43) between the two groups. At 8‐ and 12‐weeks, ISQ values remained stable (range 62–70). Radiographic analysis showed no statistically significant difference in MBL between the two implant groups after 1 year of loading neither at the mesial side (p = 0.99) or the distal side (p = 0.97). MBL for coated implants were 0.57 mm at the mesial side and 0.46 mm at the distal side. For the uncoated implants, MBL was 0.48 mm at the mesial side and 0.47 mm at the distal side. Conclusion: The zoledronate‐coated dental implants are safe to use in a one‐stage surgery protocol in patients requiring oral rehabilitation in the posterior maxilla, after 1 year of loading. There were no statically significant changes in implant stability and marginal bone levels measured by intraoral radiographs in comparison to uncoated control implants. [ABSTRACT FROM AUTHOR]

The propagation of elastic vibrations in rock samples in compression and under impacts to failure is investigated experimentally. Under impacts, a signal of acceleration was recorded in the samples, and the spectral density was calculated to determine velocities of elastic vibrations. It is found that under increasing load up to a pre-failure value, the P- and S-wave velocities grow, and the S-wave velocity increases by more than 50%. The acoustic Q-factor rises by 70%. The energy of the microseismic emission under pre-failure loads is two times higher than under low loads, and the high-amplitude spectral components generated under pre-failure loading are reflective of large discontinuities being formed. [ABSTRACT FROM AUTHOR]

Combining periodic layered structure with three-dimensional cylindrical local resonators, a hybrid metastructure with improved wave isolation ability was designed and investigated through theoretical and numerical approaches. The metastructure is composed of periodic rubber layers and concrete layers embedded with three-dimensional resonators, which can be freely designed with multi local resonant frequencies to attenuate vibrations at required frequencies and widen the attenuation bandgap. The metastructure can also effectively attenuate seismic responses. Compared with layered rubber-based structures, the metastructure has more excellent wave attenuation effects with greater attenuation and wider bandgap. [ABSTRACT FROM AUTHOR]

Bone density at the implant site is correlated to the success of osseointegration. The objective of this in vitro study was to evaluate the efficacy of osseodensification burs in increasing bone density using a solid polyurethane foam block model. The osseodensification burs kit was used to perform 48 osteotomies on a rigid polyurethane foam test ground. Burs were utilized on a TMM2 implant motor for data collection. The osteotomies were divided into two study groups (A and C) in which implant sites, extended 12 and 14 mm deep, respectively, were prepared using the drills to a compaction rotation; two control groups, B and D, represented the osteotomies for which the drills were used in cutting direction. A 3.8 × 12 mm conical implant was inserted into each site; for each implant, data were collected on the peak torque (Cp), mean torque (Cm), and integral depth curve (I). The implants underwent resonance frequency analysis (RFA) to assess the implant stability quotient (ISQ). Correlation analysis was performed between I, Cm, Cp and ISQ. One-way analysis of variance (ANOVA) was used to identify statistically significant differences between groups. Group C, representing osteotomies prepared at 14 mm with osseodensification burs, showed a significantly higher value for each parameter. Implants at sites obtained with osteocondensation drills and prepared at greater depth for autologous particle grafting showed significant increases in each implant stability parameter. [ABSTRACT FROM AUTHOR]