Search Results (145)

Achieving the appropriate primary stability for immediate or early loading in areas with low-density bone, such as the posterior maxilla, is challenging. A three-dimensional (3D) stabilization implant design featuring a tapered body with continuous cutting flutes along the length of the external thread form, with a combination of curved and linear geometric surfaces on the thread’s crest, has the capacity to enhance early biomechanical and osseointegration outcomes compared to implants with traditional buttressed thread profiles. Commercially available implants with a buttress thread design (TP), and an experimental implant that incorporated the 3D stabilization trimmed-thread design (TP 3DS) were used in this study. Six osteotomies were surgically created in the ilium of adult sheep (N = 14). Osteotomy sites were randomized to receive either the TP or TP 3DS implant to reduce site bias. Subjects were allowed to heal for either 3 or 12 weeks (N = 7 sheep/time point), after which samples were collected en bloc (including the implants and surrounding bone) and implants were either subjected to bench-top biomechanical testing (e.g., lateral loading), histological/histomorphometric analysis, or nanoindentation testing. Both implant designs yielded high insertion torque (ITV ≥ 30 N⋅cm) and implant stability quotient (ISQ ≥ 70) values, indicative of high primary stability. Qualitative histomorphological analysis revealed that the TP 3DS group exhibited a continuous bone–implant interface along the threaded region, in contrast to the TP group at the early, 3-week, healing time point. Furthermore, TP 3DS’s cutting flutes along the entire length of the implant permitted the distribution of autologous bone chips within the healing chambers. Histological evaluation at 12 weeks revealed an increase in woven bone containing a greater presence of lacunae within the healing chambers in both groups, consistent with an intramembranous-like healing pattern and absence of bone dieback. The TP 3DS macrogeometry yielded a ~66% increase in average lateral load during pushout testing at baseline (T = 0 weeks, p = 0.036) and significantly higher bone-to-implant contact (BIC) values at 3 weeks post-implantation (p = 0.006), relative to the traditional TP implant. In a low-density (Type IV) bone model, the TP 3DS implant demonstrated improved performance compared to the conventional TP, as evidenced by an increase in baseline lateral loading capacity and increased BIC during the early stages of osseointegration. These findings indicate that the modified implant configuration of the TP 3DS facilitates more favorable biomechanical integration and may promote more rapid and stable bone anchorage under compromised bone quality conditions. Therefore, such improvements could have important clinical implications for the success and longevity of dental implants placed in regions with low bone density. Full article

The rapid increase in plastic production and consumption has intensified research into human exposure to micro- and nanoplastics (MNPs) and their health effects. This study quantitatively assessed MNP internal exposure levels in non-invasive human samples, focusing on the four most common types of MNPs (≥300 nm): polyethylene terephthalate (PET), polypropylene (PP), low-density polyethylene (LDPE), and polystyrene (PS). Urine samples from 18 volunteers (4 males, 14 females) were analyzed using pyrolysis–gas chromatography–mass spectrometry (Py-GC/MS) with P(E-¹³C₂) as an internal standard. The study developed a straightforward yet effective analytical approach for quantifying MNPs in biological fluids. MNPs were detected in all urine samples, with concentrations ranging from 0.098 to 0.986 μg/mL and an average concentration of 0.268 ± 0.235 μg/mL. LDPE, 0.074 μg/mL (interquartile range: 0.030–0.243 μg/mL), was the most abundant polymer, accounting for 67.72% of the total MNPs, followed by PS at 21.17%, while PP and PET accounted for 7.06% and 4.05%, respectively. The results also suggest that drinking water type may serve as a distinct source of MNPs in urine. This study provides novel evidence on MNP (≥300 nm) internal exposure in humans and the influence of drinking habits, highlighting the application prospects of this method in assessing the potential health risks of MNPs. Full article

Background: Wettability of dental implant surfaces is a key factor in the osteointegration process. This study aimed to evaluate the effect of a new hydrophilic surface on implant stability in posterior maxilla rehabilitations. Materials and Methods: A 6-month, single-center, parallel-group clinical trial following STROBE guidelines was reported. Implant Stability Quotient (ISQ) changes were compared between implants with a moderately rough surface (MultiNeO CS, Alpha-Bio Tec, Israel, Control Group–CG) and those with the same surface and, in addition, nano-scale roughness and hydrophilic properties (MultiNeO NH CS, Alpha-Bio Tec, Israel, Test Group–TG) placed using a crestal sinus lift technique. ISQ values at bucco-lingual (ISQBL) and mesio-distal (ISQMD) sides were measured at insertion (t0), 4 months (t4), and 6 months (t6). Repeated measures ANOVA (RMA) was performed for statistical evaluation. Results: The study included 35 participants (18 TG, 17 CG). Mean ISQBL0 was 69.45 (SD = 12.62), increasing to 71.72 (SD = 6.74) at t4 and 75.21 (SD = 4) at t6. ISQMD0 mean was 67.54 (SD = 12.54), rising to 72.32 (SD = 6.90) at t4 and 75.67 (SD = 4.60) at t6. No statistically significant differences were found between groups, though TG showed a significant increase in ISQBL at t6 vs. t4 and ISQMD at t6 vs. t0. One-way ANOVA revealed no significant variations between mean ISQ differences over time. Conclusion: Both groups exhibited an increasing ISQ trend, but no significant differences were observed between t4–t0 and t6–t4 periods. Further research is required to assess the impact of hydrophilia on early loading, osteointegration, and long-term outcomes. Full article

Objectives: We wished to compare the primary and secondary stability of dental implants with a progressive design (PL) versus a conventional thread design (SL) across various clinical settings. Methods: A total of 100 implants (50 PL and 50 SL) were placed in 62 patients. The stability of the implants was assessed using a resonance frequency analysis (RFA) at the time of placement (T1) and 20 weeks postoperatively before prosthetic loading (T2). Bone density was measured in Hounsfield units (HU) using cone-beam computed tomography (CBCT). The ISQ values were recorded for each group and anatomical region, including both inter- and intragroup comparisons over time. Results: Both implant designs showed a significant increase in stability during the healing period. At T1, the ISQ values were comparable between groups (SL: 71.3 ± 8.6; PL: 71.1 ± 8.7). At T2, the ISQ values increased significantly in both groups (SL and PL: p < 0.01), with no statistically significant difference in the degree of the gain in stability. The ISQ values were generally lower in the maxilla compared to those in the mandible. In the posterior mandible, the SL implants demonstrated a greater increase in stability compared to that with the PL implants. A strong positive correlation between the HU and ISQ values was observed for both groups (SL: r = 0.95; PL: r = 1.00), without reaching statistical significance. Conclusions: While the progressive thread design aims to enhance the primary stability, it did not outperform the conventional design in this study. Both implant types proved effective in achieving stable and predictable clinical outcomes. Full article

This study investigates the influence of wave-climate datasets derived from in situ measurements and reanalysis models on predictive modelling accuracy for coastline evolution, focusing on the IJmuiden coastal stretch in The Netherlands. By analyzing wave parameters, sediment dynamics, and nourishment interventions, the research evaluates the performance of a numerical model in simulating shoreline changes over a 40-year period. Using the LTC (Long-Term Configuration) model, scenarios incorporating artificial sand nourishment volumes of 200,000 m³/year and 250,000 m³/year were tested against conditions without nourishment. The results highlighted the critical role of significant wave height, direction, and dataset variability in sediment accretion and erosion patterns. Datasets from in situ measurements (Measured-YM6) and reanalysis sources (ERA5, AENWS-WPR, and AENWS-WPR North) demonstrate variable performance, with ERA5 proving to be the most reliable under both nourished and non-nourished scenarios. The findings emphasize the importance of integrating high-resolution wave datasets into numerical models to improve predictions, optimize nourishment strategies, and enhance coastal resilience against erosion. The study underscores the necessity of nourishment interventions to mitigate sediment loss, stabilize shorelines, and support sustainable coastal-management practices in the face of climate change. Full article

This study aimed to utilize finite element analysis (FEA) to evaluate the primary stability of Cyroth dental implants (AoN Implants Srl, Grisignano di Zocco, Italy) under various biomechanical conditions, including different implant inclinations (0°, 15°, and 20°) and bone densities (D3 and D4). By comparing these results with those obtained from in vitro tests on polyurethane blocks, the study sought to determine whether FEA could provide stability information more quickly and efficiently than in vitro methods. The research involved correlating dental implant micro-mobility with the implant stability quotient (ISQ) using FEA to simulate the mechanical behavior of implants and the surrounding bone tissue. Additionally, the study assessed the error in ISQ value detection by comparing FEA results with in vitro tests on polyurethane blocks conducted under the same experimental conditions. Both the FEA simulations and in vitro experiments demonstrated similar trends in ISQ values. For the D3 bone block simulated by FEA, the difference from the in vitro test was only 1.27%, while for the D2 bone, the difference was 2.86%. The findings also indicated that ISQ increases with implant inclination and that bone quality significantly affects primary stability, with ISQ decreasing as bone density diminishes. Overall, this study showed that ISQ evaluation for dental implants can be effectively performed through FEA, particularly by examining micro-movements. The results indicated that FEA and in vitro polyurethane testing yielded comparable outcomes, with FEA providing a faster and more cost-effective means of assessing ISQ across various clinical scenarios compared to in vitro testing. Full article

Background: The physicochemical changes of the surface aim to improve cell adhesion, proliferation, and differentiation, that is, better biological interaction with the cells and, consequently, with the peri-implant tissues. In the present study, implants with the same macrogeometry were compared in vitro and in vivo, but with two different surfaces: micro-rough and a new micro-nano-rough surface. Materials and Methods: A total of 90 implants were used, 10 of which were used for in vitro surface characterization (n = 5 per group) through scanning electron microscopy (SEM), atomic force microscopy (AFM), and surface roughness measurements. For in vivo tests, 80 implants (n = 40 per group) were used in 20 rabbits (n = 2 implants per tibia). Two experimental groups were created: a control group, where the implants had a surface treated by sandblasting with titanium oxide microparticles, and a test group, where the implants were sandblasted using the same process as the previous group plus acid conditioned. The implant stability quotient (ISQ) was measured by resonance frequency (initially and at both euthanasia times). Animals were euthanized 3 and 5 weeks after implantation (n = 10 animals per time). Ten samples from each group at each time point were evaluated by removal torque (RTv). Another ten samples from each group were evaluated histologically and histomorphometrically, measuring the percentage of bone-to-implant contact (%BIC) and the bone area fraction occupancy (%BAFO). Results: In vitro, it was possible to observe a more homogeneous surface for the test group compared to the control group. ISQ values showed statistical differences at both 3 and 5 weeks (test > control). For RTv, the values were: 44.5 ± 4.25 Ncm (control group) and 48.6 ± 3.17 Ncm (test group) for the time of 3 weeks; 64.3 ± 4.50 Ncm (control group) and 76.1 ± 4.18 Ncm (test group) at 5 weeks. The %BIC and %BAFO values measured in both groups and at both times did not show significant differences (p > 0.05). Conclusions: The higher removal torque and ISQ values presented in the samples from the test group compared to the control group indicate that there was an acceleration in the mineralization process of the newly formed bone matrix. Full article

Background: Immediate post-extraction dental implants are increasingly popular, but ensuring primary stability and managing peri-implant tissues remain challenging. Implant macro-design significantly impacts stability and osseointegration. This study used Cone-beam Computed Tomography (CBCT) to evaluate changes in alveolar bone following immediate placement of two implant designs, System 2P and Dura-Vit 3P, which feature semi-conical microgeometry and apical self-tapping portions for improved stability and bone regeneration. Methods: With a 1:1 allocation ratio, the current investigation was a two-arm parallel group randomized clinical trial. Patients qualified if they required immediate dental replacements with adequate buccal bone support. Two types of implants were placed: System 2P (cylindrical shape) and Dura-Vit 3P (more conical shape, with a particular architecture of threads). Following the intervention, CBCT was performed both immediately (T1) and six months later (T2). Measurements of CBCT horizontal bone level at apical, medial, and bevel height on the palatal/lingual and vestibular sides as well as the buccal vertical gap were the primary results. Complications, implant stability quotient (ISQ), and torque insertion were evaluated. The Mann–Whitney test was used to determine time-based differences within each group, while the Wilcoxon test was used to estimate differences between groups. The impact of baseline marginal gap dimension and gingival biotype was estimated using multiple regressions. Results: Thirty patients were recruited and randomized to treatments, with two lost to follow-up. One System 2P implant failed and two patients of the Dura-Vit 3P group dropped out. At T1, the Dura-Vit 3P group exhibited a lower mean insertion torque and a higher ISQ than the System 2P group. Furthermore, the Dura-Vit 3P group showed lower bone reduction compared to System 2P at horizontal and vertical measurements with significant differences for the vestibular and palatal base and medial level (p-values < 0.05). Regression models indicated a positive effect of thick biotypes on gap filling and dimensional bone reduction. No complications were observed in both groups. Conclusions: The Dura-Vit 3P implant exhibits high primary stability when inserted in post-extraction sites. Furthermore, this kind of implant stimulates higher bone stability on both the palatal and buccal side when compared to the System 2P implant. The present findings support the evidence that the macro-design of the Dura-Vit 3P implant promotes increased primary stability and reduces bone loss. Full article

Primary dental implant stability is critical to enable osseointegration. We assessed the primary stability of our newly designed dental implant. We used the calf rib bone animal model. Our implant has an outside tapered screw with two inside barrettes that deploy with a second screw situated at the implant’s crown. We used ten calf ribs with III/IV bone density and inserted ten implants per rib. We deployed the barrettes in the calf rib’s transversal direction to support against the nearby cortical bone. We measured the primary implant’s stability with resonance frequency analysis and collected the Implant Stability Quota (ISQ) in the transverse and longitudinal calf rib planes before (PRE) and after (POS) deploying the barrette. The mean ISQ was PRE 84.00 ± 3.56 and POS 84.73 ± 4.53 (p = 0.84) in the longitudinal plane and PRE 81.80 ± 2.74 and POS 83.53 ± 4.53 (0.27) in the transverse plane. The barrettes’ insertion increases our dental implant primary stability by 11% in the transverse plane and 2% in the longitudinal plane. Our dental implant ISQ values are in the higher range than those reported in the literature and reflect high primary stability after insertion. The barrette deployment improves the dental implant’s primary stability, particularly in the direction in which it deploys (transverse plane). Full article

Objectives: This retrospective cohort study aimed to compare and evaluate the 1-year stability of two Korean implant brands, Osstem and Toplan, both treated with alumina- sandblasting and acid- etching (SA) surface modification. Methods: This retrospective analysis evaluated patients with American Society of Anesthesiologists grade I or II, >20 years, with alveolar bone volume suitable for implant placement, who received immediate or delayed placement after extraction, and with Osstem (n = 57) or Toplan (n = 87) implants. The insertion torque value (ITV) measured on the day of implant placement and the implant stability quotient (ISQ) measured on the day of implant placement, 1 month post-surgery, and 2–3 months after implantation were analyzed. Results: Both implants had significantly increased ISQs over time, and the ISQs did not significantly differ between Osstem and Toplan implants at any time point. Osstem implants showed significantly higher ISQs in D2 than in D3 bone, and in the mandible than in the maxilla at all time points. Toplan implants with diameters >4.0 mm showed higher initial ISQs. Osstem implants showed a significant correlation between ITV and ISQ on the day of placement (r = 0.349, p < 0.01) but not at later time points. For Toplan implants, no significant correlation was confirmed between ITV and ISQ at any time point. At the 1-year follow-up, both implants were still providing functional service. Conclusions: Osstem and Toplan implants with SA surface treatment showed a high level of stability for 1 year, and no significant difference in stability was observed between the two implants. Both implants are considered clinically reliable products. Full article

Background/Objectives: Primary stability is an important factor for dental implant success, and a high insertion torque (IT) is recommended in cases where an immediate load is required or desired. At the same time, some authors have claimed that it can interfere with bone-to-implant healing. This study aimed to compare the survival rates of implants inserted with different torques in full-arch cases, with or without immediate load, with up to 2-year follow-up. Methods: This study included subjects who required full-arch rehabilitation with implants. All cases were planned for the placement of four implants on each arch and were divided into groups according to the IT and had implant stability quotient (ISQ) measurements taken periodically for up to 2 years. Results: No implant was lost during this period, and no significant differences in peri-implant bone loss were observed. The paired t-test was performed to determine the association between ISQ and IT. Conclusions: The results suggest that initial torques higher than 75 Ncm may not be harmful to the stability of implants placed for full-arch rehabilitation, at least during the study period. Further clinical studies with longer follow-up periods are necessary to confirm these results. Full article

This study aimed to evaluate the biomechanical performance of two truncated cone implant designs in maxillary sinus lift (MSL) procedures using polyurethane laminas. A total of 128 implants were used. Polyurethane laminas were divided into two groups based on thickness (1 and 3 mm) and two subgroups based on density (20 and 30 pounds per cubic foot, PCF). Each subgroup tested two implants (Sinus-plant and Sinus Lift Concept: SLC), resulting in 8 experimental conditions and 16 implants per condition. The insertion torque (IT), removal torque (RT), and implant stability quotient (ISQ) were measured. SLC implants achieved significantly higher IT and RT across all tested conditions (p < 0.0001), reporting the highest values at the 30 PCF/3 mm lamina (IT: 34.09 ± 0.32 Ncm; RT: 32.15 ± 0.29 Ncm) and the lowest at the 20 PCF/1 mm lamina (IT: 11.86 ± 0.22 Ncm; RT: 10.28 ± 0.22 Ncm). Additionally, SLC implants achieved significantly higher ISQ values, ranging from around 61 to 48 ISQ. Notably, this difference was not significant at the 20 PCF/3 mm lamina, highlighting that bone density may play a more critical role than thickness for SLC implants. This study simulated the clinical condition of achieving primary stability even with extreme maxillary bone thickness. The findings indicate that while both implant designs can be utilized in MSL procedures, the SLC is particularly effective in scenarios with limited bone thickness and density, potentially allowing for simultaneous MSL, implant placement, and healing screw application. Full article

Background and Objectives: Dental implants are a reliable solution for tooth loss; however, systemic conditions like osteoporosis and diabetes, which affect bone quality, healing, and stability, underline the importance of understanding their impact on enhanced outcomes. This study evaluated the comparative effects of osteoporosis and diabetes on dental implant stability over 12 months, utilizing objective implant mobility and stability measures. Materials and Methods: This prospective cohort study involved 50 patients, divided into 21 with type 2 diabetes and 29 with osteoporosis, with implant stability assessed at 6 and 12 months using Osstell ISQ and Periotest M devices and statistical analysis identifying differences between groups and time intervals at a significance level of p < 0.05. Results: At 6 months, the osteoporosis group showed higher initial stability (mean ISQ: 67.04 ± 5.42) compared to the diabetes group (mean ISQ: 62.10 ± 5.46; p = 0.0215)), and by 12 months, both groups showed significant improvements in ISQ scores (osteoporosis: 68.93 ± 4.83; diabetes: 65.79 ± 3.87), with Periotest values indicating more significant reductions in implant mobility, particularly in diabetic patients (osteoporosis: −3.34 ± 1.59; diabetes: −2.81 ± 1.44; p = 0.0001). Conclusions: Osteoporosis and diabetes significantly impact implant stability through distinct osseointegration pathways, emphasizing the need for personalized treatment plans to improve patient outcomes. Full article

Background/Objectives: Dry eye disease (DED) significantly impairs quality of life, affecting physical, social, and psychological well-being, as well as reducing workplace productivity. While lutein and zeaxanthin supplements have been shown to improve ocular health, existing research often overlooks the efficacy of lower dosages and shorter durations of supplementation. This study investigated the effects of combined supplementation with lutein, zeaxanthin, and elderberries in 110 voluntary participants through a randomized controlled trial. Methods: Participants took 6 mg of lutein and 1 mg of zeaxanthin, along with 100 mg elderberry extract once daily for a duration of 20 days. Ocular health was assessed using the Ocular Surface Disease Index (OSDI), while immune status was evaluated with the Immune Status Questionnaire (ISQ). Results: Results showed that combined supplementation significantly (p < 0.05) reduced the OSDI scores in the intervention group from 38.15 ± 11.14 to 18.26 ± 5.57, reflecting a 52.2% reduction. A similar trend was observed with the Visual Analog Scale (VAS), indicating significant (p < 0.05) improvement from 5.31 ± 1.62 to 6.73 ± 1.74, equivalent to a 26.7% improvement. Although the intervention group showed a 15.9% improvement in ISQ scores by the study’s end, this was not significantly different from the placebo group, suggesting that higher dosages or longer durations may be needed to observe a meaningful effect. Additionally, findings from the Food Frequency Questionnaire revealed that the average dietary intake of lutein and zeaxanthin among participants was only 663.49 µg, equating to just 5.5% of the suggested optimal daily intake. This low consumption is concerning, as it is inversely correlated with the risk of ocular diseases. Conclusions: Collectively, these findings support the use of combined supplementation as an adjuvant approach to improving ocular health. Full article

Background: This study aimed to evaluate the primary stability, according to the insertion torque value (ITV) and resonance frequency analysis (RFA), of dental implants placed in standardized blocks of bone quality equivalent to type II-A bone, using three surgical undersized protocols of 0.2 mm, 0.5 mm, and 0.8 mm, considering different dental implant diameters and lengths. Methods: One hundred and twenty dental implants (DIs) of different diameters (3.5, 3.8, 4.5, and 5.0 mm) and lengths (8.5, 10.0, 11.5, 13.0, and 15.0 mm) placed in polyurethane blocks equivalent to type II-A bone, according to the Lekholm and Zarb classification modified by Rosas et al., were examined with three surgical protocols of under-milling of 0.2, 0.5, and 0.8 mm. The ITV and the RFA were the determinants of primary stability, and their respective values were recorded as Ncm and the implant stability quotient (ISQ) immediately after the placement of the DIs. These were evaluated according to each surgical insertion protocol, length, and diameter of the DI under a multivariate analysis model (MANOVA). Statistical significance was set at p < 0.05. Results: It was observed that the average of the ITV was significantly higher when a 0.8 mm under-milling protocol was used (63.2 ± 14.9 Ncm) (p < 0.001). However, the ITV was significantly lower when a 0.2 mm under-milling protocol was used (25.1 ± 8.3 Ncm) (p < 0.001). On the other hand, the ISQ did not present significant differences (p = 0.166) when comparing the 0.2 (67.6 ISQ ± 5.4 ISQ), 0.5 (65.8 ISQ ± 3.4 ISQ), and 0.8 (65.7 ISQ ± 4.0 ISQ) under-milling protocols in the evaluation of the primary stability of the dental implant. The multivariate effect size (ηp² = 0.639) indicated that the variability detected in the insertion torque and the ISQ, at the same time, was explained by 63.9% (p < 0.001) due only to the compression protocol, while the implant diameter explained this variability by 27.0% (ηp² = 0.270) (p < 0.001) and the implant length only significantly explained this variability by 12.1% (ηp² = 0.121) (p = 0.030). Finally, any interaction between the compression protocol, implant diameter, and length did not influence insertion torque variability or the ISQ (p > 0.05). Conclusions: It can be concluded that when the surgical protocol for subpreparation is optimal according to the prepared bone bed, regardless of the diameter or length of the dental implant used, primary stability was assured according to the ITV and the RFA in 63.9%. This finding allows us to recommend carrying out a correct analysis of bone quality in order to subsequently select the most appropriate surgical protocol for the subpreparation of the bone bed to achieve better primary stability of the dental implant. Full article