Transport Properties in Multicomponent Systems Containing Cyclodextrins and Nickel Ions.

In this work, we propose a comprehensive experimental study of the diffusion of nickel ions in combination with different cyclodextrins as carrier molecules for enhanced solubility and facilitated transport. For this, ternary mutual diffusion coefficients measured by Taylor dispersion method are reported for aqueous solutions containing nickel salts and different cyclodextrins (that is, α-CD, ß-CD, and γ-CD) at 298.15 K. A combination of Taylor dispersion and other methods, such as UV-vis spectroscopy, will be used to obtain complementary information on these systems. The determination of the physicochemical properties of these salts with CDs in aqueous solution provides information that allows us to understand solute-solvent interactions, and gives a significant contribution to understanding the mechanisms underlying diffusional transport in aqueous solutions, and, consequently, to mitigating the potential toxicity associated with these metal ions. For example, using mutual diffusion data, it is possible to estimate the number of moles of each ion transported per mole of the cyclodextrin driven by its own concentration gradient.

Effects of resource availability and interspecific interactions on Arctic and red foxes' winter use of ungulate carrion in the Fennoscandian low-Arctic tundra.

In the Arctic tundra, predators face recurrent periods of food scarcity and often turn to ungulate carcasses as an alternative food source. As important and localized resource patches, carrion promotes co-occurrence of different individuals, and its use by predators is likely to be affected by interspecific competition. We studied how interspecific competition and resource availability impact winter use of carrion by Arctic and red foxes in low Arctic Fennoscandia. We predicted that the presence of red foxes limits Arctic foxes' use of carrion, and that competition depends on the availability of other resources. We monitored Arctic and red fox presence at supp lied carrion using camera traps. From 2006 to 2021, between 16 and 20 cameras were active for 2 months in late winter (288 camera-winters). Using a multi-species dynamic occupancy model at a week-to-week scale, we evaluated the use of carrion by foxes while accounting for the presence of competitors, rodent availability, and supplemental feeding provided to Arctic foxes. Competition affected carrion use by increasing both species' probability to leave occupied carcasses between consecutive weeks. This increase was similar for the two species, suggesting symmetrical avoidance. Increased rodent abundance was associated with a higher probability of colonizing carrion sites for both species. For Arctic foxes, however, this increase was only observed at carcasses unoccupied by red foxes, showing greater avoidance when alternative preys are available. Supplementary feeding increased Arctic foxes' carrion use, regardless of red fox presence. Contrary to expectations, we did not find strong signs of asymmetric competition for carrion in winter, which suggests that interactions for resources at a short time scale are not necessarily aligned with interactions at the scale of the population. In addition, we found that competition for carcasses depends on the availability of other resources, suggesting that interactions between predators depend on the ecological context.

Rehabilitation of full-arch edentulism with fixed or removable dentures retained by root-form dental implants: A systematic review of outcomes and outcome measures used in clinical research in the last 10 years.

AIM: To evaluate outcome measures, methods of assessment, and analysis in clinical studies on the rehabilitation of full-arch edentulism with implant-supported fixed or removable prostheses. MATERIALS AND METHODS: A protocol-oriented search was conducted in MEDLINE via PubMed, EMBASE, and Cochrane Library (PROSPERO registration CRD42021265179) from 1 January 2011 to 27 July 2021 to identify longitudinal studies reporting on the rehabilitation of edentulous patients with implant-supported prostheses. The primary aim of this study was the collection of all objectively reported outcomes in each study. Secondary aims included the description of the methods of assessment and analytical methods. Risk of bias was applied according to the study design (randomized controlled trial, cohort study, or descriptive pre-post study). Individual study data were extracted into an outcomes matrix. Outcomes were grouped into domains and descriptively analysed. A network diagram was generated to establish relationships between domains. The present review follows the PRISMA statement. RESULTS: The screening and selection processes resulted in the identification of 491 publications, corresponding to 421 different studies (cohorts of patients). Only 24% of the studies reported the use of EQUATOR network guidelines. Implant failure/survival was the most reported outcome (270 studies), but the criterion to determine implant failure and/or survival was frequently not described or was ambiguous. Implant success was much less frequently reported (88) and was based on several heterogenous composite definitions. Marginal bone levels (233 studies), technical complications (158), and clinical outcomes (150), including peri-implant soft tissue and implant stability assessment, were also frequently reported. Patient-reported outcome measures (PROMs) (145) and function-based outcomes (40) were predominantly reported in isolation from other outcomes and most frequently in removable restorations. While quality of life was evaluated using valid instruments, patient satisfaction was evaluated based on a common sense concept of satisfaction. Economic outcomes were under-reported (13). CONCLUSIONS: There is great heterogeneity in the criteria to define implant failure or survival and implant success, which prevents the comparison of rates across studies. Even though studies frequently report multiple outcomes, PROMs are usually reported in isolation from other outcomes. It would be valuable to have a set of core outcome variables and standardized methods of measurement for future studies.

Scientific rationale for study: Consistent data on the outcomes of treatments for full-arch edentulism are fundamental for establishing high-quality clinical practices with effective impact on patients' lives. Principal findings: Despite the increasing number of studies assessing the rehabilitation of full-arch edentulism with implant-supported prostheses, there has been little adherence to reporting guidelines (EQUATOR network), resulting in high variability regarding the type of outcomes reported. The clinical performance of these restorations has been mostly evaluated using clinician-oriented and patient-reported outcomes. Assessment methods are frequently not described and vary across studies. Practical implications: It would be valuable to have a set of core outcome variables and standardized methods of measurement for future studies.

Rehabilitation of full-arch edentulism with fixed or removable dentures retained by root-form dental implants: A systematic review of outcomes and outcome measures used in clinical research in the last 10 years.

AIM: To evaluate outcome measures, methods of assessment, and analysis in clinical studies on the rehabilitation of full-arch edentulism with implant-supported fixed or removable prostheses. MATERIALS AND METHODS: A protocol-oriented search was conducted in MEDLINE via PubMed, EMBASE, and Cochrane Library (PROSPERO registration CRD42021265179) from 1 January 2011 to 27 July 2021 to identify longitudinal studies reporting on the rehabilitation of edentulous patients with implant-supported prostheses. The primary aim of this study was the collection of all objectively reported outcomes in each study. Secondary aims included the description of the methods of assessment and analytical methods. Risk of bias was applied according to the study design (randomized controlled trial, cohort study, or descriptive pre-post study). Individual study data were extracted into an outcomes matrix. Outcomes were grouped into domains and descriptively analysed. A network diagram was generated to establish relationships between domains. The present review follows the PRISMA statement. RESULTS: The screening and selection processes resulted in the identification of 491 publications, corresponding to 421 different studies (cohorts of patients). Only 24% of the studies reported the use of EQUATOR network guidelines. Implant failure/survival was the most reported outcome (270 studies), but the criterion to determine implant failure and/or survival was frequently not described or was ambiguous. Implant success was much less frequently reported (88) and was based on several heterogenous composite definitions. Marginal bone levels (233 studies), technical complications (158), and clinical outcomes (150), including peri-implant soft tissue and implant stability assessment, were also frequently reported. Patient-reported outcome measures (PROMs) (145) and function-based outcomes (40) were predominantly reported in isolation from other outcomes and most frequently in removable restorations. While quality of life was evaluated using valid instruments, patient satisfaction was evaluated based on a common sense concept of satisfaction. Economic outcomes were under-reported (13). CONCLUSIONS: There is great heterogeneity in the criteria to define implant failure or survival and implant success, which prevents the comparison of rates across studies. Even though studies frequently report multiple outcomes, PROMs are usually reported in isolation from other outcomes. It would be valuable to have a set of core outcome variables and standardized methods of measurement for future studies.

Seasonality, density dependence, and spatial population synchrony.

Studies of spatial population synchrony constitute a central approach for understanding the drivers of ecological dynamics. Recently, identifying the ecological impacts of climate change has emerged as a new important focus in population synchrony studies. However, while it is well known that climatic seasonality and sequential density dependence influences local population dynamics, the role of season-specific density dependence in shaping large-scale population synchrony has not received attention. Here, we present a widely applicable analytical protocol that allows us to account for both season and geographic context-specific density dependence to better elucidate the relative roles of deterministic and stochastic sources of population synchrony, including the renowned Moran effect. We exemplify our protocol by analyzing time series of seasonal (spring and fall) abundance estimates of cyclic rodent populations, revealing that season-specific density dependence is a major component of population synchrony. By accounting for deterministic sources of synchrony (in particular season-specific density dependence), we are able to identify stochastic components. These stochastic components include mild winter weather events, which are expected to increase in frequency under climate warming in boreal and Arctic ecosystems. Interestingly, these weather effects act both directly and delayed on the vole populations, thus enhancing the Moran effect. Our study demonstrates how different drivers of population synchrony, presently altered by climate warming, can be disentangled based on seasonally sampled population time-series data and adequate population models.

Diffusion of Vanadium Ions in Artificial Saliva and Its Elimination from the Oral Cavity by Pharmacological Compounds Present in Mouthwashes.

In this study, diffusion coefficients of ammonium vanadate at tracer concentrations in artificial saliva with and without sodium fluoride, at different pH values, were measured using an experimental model based on the Taylor dispersion technique. Ternary mutual diffusion coefficients (D11, D22, D12, and D21) for four aqueous systems {NH4VO3 (component 1) + ß-cyclodextrin (ß-CD) (component 2),} {NH4VO3 (component 1) + ß-cyclodextrin (HP-ß-CD) (component 2)}, {NH4VO3 (component 1) + sodium dodecyl sulphate (SDS) (component 2)} and {NH4VO3 (component 1) + sodium hyaluronate (NaHy) (component 2)} at 25.00 °C were also measured by using the same technique. These data showed that diffusion of ammonium vanadate was strongly affected in all aqueous media studied. Furthermore, a significant coupled diffusion of this salt and ß-CD was observed through the non-zero values of the cross-diffusion coefficients, D12, allowing us to conclude that there is a strong interaction between these two components. This finding is very promising considering the removal, from the oral cavity, of vanadium resulting from tribocorrosion of Ti-6Al-4V prosthetic devices.

Effect of Cobalt and Chromium Ions on the Chlorhexidine Digluconate as Seen by Intermolecular Diffusion.

Metal ions such as cobalt (II) and chromium (III) might be present in the oral cavity, as a consequence of the corrosion of Co-Cr dental alloys. The diffusion of such metal ions into the organism, carried by saliva, can cause health problems as a consequence of their toxicity, enhanced by a cumulative effect in the body. The effect of the chlorhexidine digluconate, which is commonly used in mouthwash formulations, on the transport of these salts is evaluated in this paper by using the Taylor dispersion technique, which will allow an assessment of how the presence of chlorhexidine digluconate (either in aqueous solution or in a commercial formulation) may affect the diffusion of metal ions. The ternary mutual diffusion coefficients of metal ions (Co and Cr) in the presence of chlorhexidine digluconate, in an artificial saliva media, were measured. Significant coupled diffusion of CoCl2 (and CrCl3) and chlorhexidine digluconate is observed by analysis of the non-zero values of the cross-diffusion coefficients, D12 and D21. The observed interactions between metal ions and chlorhexidine digluconate suggest that the latter might be considered as an advantageous therapeutic agent, once they contribute to the reduction of the concentration of those ions inside the mouth.

Clinical and radiographic performance of self-locking conical connection implants in the posterior mandible: Five-year results of a two-centre prospective study.

OBJECTIVE: This prospective study aims to assess the 5-year clinical performance of implants with internal conical connection and platform-switched abutments in the posterior mandible. MATERIAL AND METHODS: Healthy adults missing at least two teeth in the posterior mandible and with a natural tooth mesial to the implant site received two or three adjacent implants. After a transmucosal healing period single crown restorations were cemented on platform-switched abutments. Changes in marginal bone levels were investigated in standardized periapical radiographs from surgery and loading (baseline) to 60-months post-loading. RESULTS: Twenty-four patients received 52 implants. Bone remodelling took place between surgery and loading (mean:-0.5, SD:±0.4 mm). From loading to 60 months, there was a mean bone change of 0.27 (SD:±0.47 mm) which stabilized 24 months after prosthesis delivery (mean:0.2, SD:±0.46 mm). 71.7% of all implants presented bone preservation at 60 months irrespective of the initial insertion depth. Two implants were lost after 5 years and the success rate was 95.1%. Patient enquiry revealed high satisfaction. CONCLUSION: Internal conical connection implants with platform-switched abutments presented a high success rate and preservation of marginal bone levels at the implant shoulder after 5 years of loading.

5-Aza-2'-deoxycytidine induces a greater inflammatory change, at the molecular levels, in normoxic than hypoxic tumor microenvironment.

Hypoxia is associated with tumor aggressiveness and poor prognosis, including breast cancer. Low oxygen levels induces global genomic hypomethylation and hypermethylation of specific loci in tumor cells. DNA methylation is a reversible epigenetic modification, usually associated with gene silencing, contributing to carcinogenesis and tumor progression. Since the effects of DNA methyltransferase inhibitor are context-dependent and as there is little data comparing their molecular effects in normoxic and hypoxic microenvironments in breast cancer, this study aimed to understand the gene expression profiles and molecular effects in response to treatment with DNA methyltransferase inhibitor in normoxia and hypoxia, using the breast cancer model. For this, a cDNA microarray was used to analyze the changes in the transcriptome upon treatment with DNA methyltransferase inhibitor (5-Aza-2'-deoxycytidine: 5-Aza-2'-dC), in normoxia and hypoxia. Furthermore, immunocytochemistry was performed to investigate the effect of 5-Aza-2'-dC on NF-κB/p65 inflammation regulator subcellular localization and expression, in normoxia and hypoxia conditions. We observed that proinflammatory pathways were upregulated by treatment with 5-Aza-2'-dC, in both conditions. However, treatment with 5-Aza-2'-dC in normoxia showed a greater amount of overexpressed proinflammatory pathways than 5-Aza-2'-dC in hypoxia. In this sense, we observed that the NF-κB expression increased only upon 5-Aza-2'-dC in normoxia. Moreover, nuclear staining for NF-κB and NF-κB target genes upregulation, IL1A and IL1B, were also observed after 5-Aza-2'-dC in normoxia. Our results suggest that 5-Aza-2'-dC induces a greater inflammatory change, at the molecular levels, in normoxic than hypoxic tumor microenvironment. These data may support further studies and expand the understanding of the DNA methyltransferase inhibitor effects in different tumor contexts.

Recommendations for Implant-Supported Full-Arch Rehabilitations in Edentulous Patients: The Oral Reconstruction Foundation Consensus Report.

The tasks of Working Groups 1 to 6 at the 4th Consensus Meeting of the Oral Reconstruction Foundation were to elucidate clinical recommendations for implant-supported full-arch rehabilitations in edentulous patients. Six systematic/narrative reviews were prepared to address the following subtopics: (1) the influence of medical and geriatric factors on implant survival; (2) the prevalence of peri-implant diseases; (3) the influence of material selection, attachment type, interarch space, and opposing dentition; (4) different interventions for rehabilitation of the edentulous maxilla; (5) different interventions for rehabilitation of the edentulous mandible; and (6) treatment choice and decision-making in elderly patients. Consensus statements, clinical recommendations, and implications for future research were determined based on structured group discussions and plenary session approval.

Different Interventions for Rehabilitation of the Edentulous Maxilla with Implant-Supported Prostheses: An Overview of Systematic Reviews.

PURPOSE: To synthesize evidence derived from systematic reviews (SRs) on different interventions for rehabilitation of the edentulous maxilla with implant-supported restorations. MATERIALS AND METHODS: A protocol-oriented search was established to address the PICO question: What is the current evidence regarding rehabilitation of the edentulous maxilla with different implant-supported prostheses in terms of implant and prosthesis survival? The primary outcomes were implant and prosthesis survival rates evaluated from SRs of clinical studies including adult patients with complete edentulism of the maxilla and comparing different implant-supported rehabilitation strategies. Methodologic quality of the SRs was assessed with the AMSTAR-2 tool. RESULTS: The final selection process led to the inclusion of 36 SRs that were grouped as: (1) addressing maxillae with sufficient bone to place implants; (2) addressing maxillae with insufficient bone to place implants; and (3) comparing different types of prosthesis, number of implants, patient-reported outcomes, and economic evaluations. The literature describes four or more implants as suitable for full-arch fixed prostheses and implant-supported overdentures; in both cases, the overall survival rate is > 95%. Mini-implants present very high short-term failure rates (> 30%). Poor description of technical complications, adjustments, and maintenance and corresponding costs precluded a cost-effectiveness analysis. CONCLUSION: No implant-supported rehabilitation of the edentulous maxilla (fixed or removable) should be supported on fewer than four implants. A one-piece full-arch fixed dental prosthesis can be supported by a minimum of two anterior axial plus two posterior distally tilted implants or by six to eight axial implants symmetrically distributed through the posterior and anterior regions of the arch. Four to six implants is the advised number to support an overdenture. The use of mini-implants in the maxilla is inadvisable.

Incorporating capture heterogeneity in the estimation of autoregressive coefficients of animal population dynamics using capture-recapture data.

Population dynamic models combine density dependence and environmental effects. Ignoring sampling uncertainty might lead to biased estimation of the strength of density dependence. This is typically addressed using state-space model approaches, which integrate sampling error and population process estimates. Such models seldom include an explicit link between the sampling procedures and the true abundance, which is common in capture-recapture settings. However, many of the models proposed to estimate abundance in the presence of capture heterogeneity lead to incomplete likelihood functions and cannot be straightforwardly included in state-space models. We assessed the importance of estimating sampling error explicitly by taking an intermediate approach between ignoring uncertainty in abundance estimates and fully specified state-space models for density-dependence estimation based on autoregressive processes. First, we estimated individual capture probabilities based on a heterogeneity model for a closed population, using a conditional multinomial likelihood, followed by a Horvitz-Thompson estimate for abundance. Second, we estimated coefficients of autoregressive models for the log abundance. Inference was performed using the methodology of integrated nested Laplace approximation (INLA). We performed an extensive simulation study to compare our approach with estimates disregarding capture history information, and using R-package VGAM, for different parameter specifications. The methods were then applied to a real data set of gray-sided voles Myodes rufocanus from Northern Norway. We found that density-dependence estimation was improved when explicitly modeling sampling error in scenarios with low process variances, in which differences in coverage reached up to 8% in estimating the coefficients of the autoregressive processes. In this case, the bias also increased assuming a Poisson distribution in the observational model. For high process variances, the differences between methods were small and it appeared less important to model heterogeneity.

Immediate versus early loading protocols of titanium-zirconium narrow-diameter implants for mandibular overdentures in edentulous patients: 1-year results from a randomized controlled trial.

OBJECTIVES: The purpose of this randomized clinical trial was to compare immediate and early loading protocols for mandibular overdentures with two-splinted narrow-diameter implants in thin, non-augmented residual ridge situations. MATERIAL AND METHODS: Each edentulous patient received two implants in the interforaminal region. If primary stability after implant placement was achieved, patients were randomized either to the immediate (48 hr post-surgery) or the early (2 weeks after surgery) loading group. In prosthetic rehabilitation, a bar prosthetic system with a titanium bar was used. Implant survival, success rates, and radiographic changes at the crestal bone level were evaluated after 1 year, and patient satisfaction was recorded at 1 and 6 months post-surgery. RESULTS: Twenty-four patients with a mean age of 67 ± 9 years were included. One patient passed away after 11 months due to treatment-independent reasons. In the 24 implants of the immediate loading group, the mean bone level change from surgery/loading to the first-year evaluation was 0.32 ± 0.80 mm (p = .066). Regarding the early group (22 implants), the mean bone level change from loading to 1 year was 0.34 ± 0.69 mm (p = .048). After 1 year, no differences could be detected between groups (p = .91) with a mean difference of 0.02 mm (95% CI: [-0.42, 0.47]). The mean implant survival and success rates were 100% for both groups. Patient satisfaction was high; however, at 6 months, there was a difference between groups regarding the ability to chew. CONCLUSIONS: Both loading protocols for mandibular overdentures supported by two-splinted narrow-diameter implants were successful at the 1-year follow-up.

Peri-implant marginal bone loss reduction with platform-switching components: 5-Year post-loading results of an equivalence randomized clinical trial.

AIM: To compare the clinical performance and marginal bone levels of implants restored with platform-switching (PS) or platform-matching (PM) abutments. MATERIALS AND METHODS: Adult patients missing two or more adjacent teeth in the posterior mandible received 2-4 CAMLOG SCREW-LINE implants and were randomly allocated to the PM or PS group, receiving the corresponding prosthetic components from surgery onwards. Implants were conventionally loaded with single cemented crowns. Patients were followed annually for 5 years. Outcome measures were marginal bone level changes, implant survival, performance of the prosthetic components and clinical parameters plaque index, sulcus bleeding index and pocket probing depth. RESULTS: Thirty-three patients received 72 implants in the PM group, and thirty-five patients received 74 implants in the PS group. Sixty patients attended the final appointment, 31 had received PS components and 29 had received PM components with 65 and 63 implants, respectively. Global survival rate was 96.6% with no differences between groups (p = 0.647). After 5 years of functional loading, PS restored implants presented 0.23mm (95% CI: [0.03, 0.43], p = 0.025) lower marginal bone level changes. The two groups were declared non-equivalent. CONCLUSION: Patients requiring implant supported restorations in healed bounded or free end edentulous gaps of the mandible benefit from the use of PS components in terms of peri-implant marginal bone level maintenance, though it may not be clinically noticeable.

Influence of implant neck and abutment characteristics on peri-implant tissue health and stability. Oral reconstruction foundation consensus report.

OBJECTIVE: The aim of this consensus meeting was to assess the influence of implant neck and abutment characteristics on peri-implant tissue health and stability. MATERIAL AND METHODS: Group and plenary discussions were based on two systematic reviews focusing on the effect of titanium implants with different collar designs/surface modifications and the abutment material on the stability of marginal bone levels (MBLs), peri-implant health, and survival rates. RESULTS: The changes in MBLs were not influenced by the abutment material and were also similar at one- and two-piece implants after one year of loading. Rough collar implants improved MBLs in comparison to machined collar implants. Additional modifications of the collar had no beneficial clinical effect on MBLs. Titanium abutments were associated with significantly higher increases in bleeding on probing when compared with zirconia abutments. CONCLUSION: MBLs are mainly influenced by the microstructure (i.e., rough surfaced) of the implant neck. Consensus statements and specific recommendations for future research were elaborated during the consensus meeting.

Titanium dental implants with different collar design and surface modifications: A systematic review on survival rates and marginal bone levels.

AIM: The aim of this study was to compare clinical and radiographic outcomes of dental implants with different neck characteristics. METHODS: A protocol-oriented search aimed at the question: "In patients subjected to tooth replacement with screw-type dental implants does the modification of the implant neck macro- or microgeometry contribute to the improvement of survival rates and maintenance of the peri-implant marginal bone levels?" Primary outcomes were survival and marginal bone level (MBL) changes evaluated on randomized controlled trials with >10 participants and follow-up >1 year. Risk of bias was evaluated using the Cochrane Collaboration's tool. The review follows the PRISMA statement. RESULTS: Forty-three studies compared: (a) One- versus two-piece implants (N = 7); (b) Two-piece implants with different neck characteristics (machined and rough collars, microthreads, LASER microtexturing) (N = 21); (c) Two-piece implants with macrogeometry modifications (tapering, back-tapering, and scalloping) (N = 6). One- and two-piece implants showed similar survival (RR = 0.45, 95% CI: [0.12, 1.66], p = 0.23) and MBL changes (WMD = 0.09 mm, 95% CI: [-0.27, 0.45], p = 0.64) at 1-year post-loading. Machined collar implants have higher risk of early failure than rough collar implants (RR = 3.96, 95% CI: [1.12, 13.93], p = 0.03) and 0.43 mm higher bone resorption (95% CI: [0.0, 0.86], p = 0.05). Microthreads (WMD = 0.07 mm, 95% CI: [-0.01, 0.15], p = 0.10) and LASER microtexturing (WMD = 0.15 mm, 95% CI: [-0.35, 0.65], p = 0.56) do not reduce bone resorption. Scalloped implants have 1.26 mm higher resorption (95% CI: [0.72, 2.00], p < 0.001). CONCLUSIONS: One- and two-piece implants have similar survival and MBL changes. Rough collar implants have lower MBL changes than machined collar implants. Additional modifications to rough collars are irrelevant.

10-year outcomes with immediate and early loaded implants with a chemically modified SLA surface.

The aim of this study was to evaluate long-term outcomes in a 10-year follow-up study of patients who previously completed a 3-year multicenter randomized controlled trial of immediate and early loading of dental implants with a hydrophilic and chemically active surface (SLActive) in the posterior maxilla or mandible. The patients received implants to replace at least one missing tooth, with provisional restoration on the day of surgery (immediate loading) or 28 to 34 days later (early loading). Implant survival, change in crestal bone level, and patient satisfaction were evaluated. In total, 56 patients (with 72 implants) were available after 10 years and fulfilled the criteria for the radiographic bone level evaluation. The mean crestal bone level change from implant surgery to 10 years was -2.00 ± 1.19 mm and -1.37 ± 1.06 mm in the immediate and early groups, respectively. The corresponding change between 5 to 6 months' post-surgery (permanent fixed restoration placement) and 10 years was -1.25 ± 0.99 mm and -0.89 ± 1.11 mm in the immediate and early groups. After the initial remodeling phase (5 to 6 months) where the depth of implant placement had an influence on the initial bone remodeling, no significant differences between the two treatment groups were detected. Mean implant survival was 97.6% (98.2% and 97.1% in the immediate and early loading groups, respectively). Implants with the SLActive surface show successful long-term outcomes following immediate or early loading in posterior maxillae and mandibles.

Effect of round curvature of anterior implant-supported zirconia frameworks: finite element analysis and in vitro study using digital image correlation.

Two groups of 4-unit zirconia frameworks were produced by CAD/CAM to simulate the restoration of an anterior edentulous gap supported by 2 implant-abutment assemblies. Group 1 comprised straight configuration frameworks and group 2 consisted of arched frameworks. Specimens were made with the same connector cross-section area and were cemented and submitted to static loads. Displacements were captured with two high-speed photographic cameras and analysed with video correlation system. Frameworks and the implant-abutment assembly were scanned and converted to 3DCAD objects by reverse engineering process. A specimen of each group was veneered and the corresponding 3D geometry was similarly obtained after scanning. Numerical models were created from the CAD objects and the FE analysis was performed on the zirconia frameworks and on the FPDs bi-layered with porcelain (veneered frameworks). Displacements were higher for the curved frameworks group, under any load. The predicted displacements correlated well with the experimental values of the two framework groups, but on the straight framework the experimental vertical displacements were superior to those predicted by the FEA. The results showed that the round curvature of zirconia anterior implant-supported FPDs plays a significant role on the deformation/stress of FPDs that cannot be neglected neither in testing nor in simulation and should be considered in the clinical setting.

Effect of intentional abutment disconnection on the micro-movements of the implant-abutment assembly: a 3D digital image correlation analysis.

BACKGROUND: Implant-abutment assembly stability is critical for the success of implant-supported rehabilitation. The intentional removal of the prosthetic components may hamper the achievement of the essential stability due to preload reduction in the screw joint and implant-screw mating surface changes. OBJECTIVE: To evaluate the effect of intentional abutment disconnection and reconnection in the stability of internal locking hex implants and corresponding abutments using the method of 3D digital image correlation. MATERIAL AND METHODS: Ten conical shape and internal hexagon connection implants were embedded in acrylic resin and assembled to prosthetic abutments with 30 Ncm torque and assigned to two groups: group 1 - tested for static load-bearing capacity at 30° off-axis for two times and group 2 - underwent intentional disconnection and reconnection between tests. Micro-movements were captured with two high-speed photographic cameras and analyzed with video correlation system in three spacial axes U, V and W. Screw abutment and internal implant thread morphology was observed with a field-emission scanning electron microscopy. RESULTS: After the intentional disconnection of the abutment, group 2 showed generally higher maximum displacements for U and V directions. Under 50N load, mean difference was 24.7 µm (P = 0.008) for U direction and -7.7 µm (P = 0.008) for V direction. No significant differences were found for maximum and minimum displacements in the W direction. Mean displacement of the speckle surface presented was statistically different in the two groups (P = 0.016). SEM revealed non-homogenous screw surfaces with scoring on group 2 plus striations and debris in the implant threads. CONCLUSION: Micro-movements were higher for the group submitted to intentional disconnection and reconnection of the abutment, particularly under average bite forces.

Effect of geometry on deformation of anterior implant-supported zirconia frameworks: An in vitro study using digital image correlation.

PURPOSE: To evaluate the effect of geometry on the displacement and the strain distribution of anterior implant-supported zirconia frameworks under static load using the 3D digital image correlation method. METHODS: Two groups (n=5) of 4-unit zirconia frameworks were produced by CAD/CAM for the implant-abutment assembly. Group 1 comprised five straight configuration frameworks and group 2 consisted of five curved configuration frameworks. Specimens were cemented and submitted to static load up to 200N. Displacements were captured with two high-speed photographic cameras and analyzed with video correlation system in three spacial axes U, V, W. Statistical analysis was made using the nonparametric Mann-Whitney test. RESULTS: Up to 150N loads, the vertical displacements (V axis) were statistically higher for curved frameworks (-267.83±23.76µm), when compared to the straight frameworks (-120.73±36.17µm) (p=0.008), as well as anterior displacements in the W transformed axis (589.55±64.51µm vs 224.29±50.38µm for the curved and straight frameworks), respectively (p=0.008). The mean von Mises strains over the surface frameworks were statistically higher for the curved frameworks under any load. CONCLUSION: Within the limitations of this in vitro study, it is possible to conclude that the geometric configuration influences the deformation of 4-unit anterior frameworks under static load. The higher strain distribution and micro-movements of the curved frameworks reflect less rigidity and increased risk of fractures associated to FPDs.