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Purpose: To test a newly introduced implant-abutment material combination against bacterial endotoxin leakage in a human whole blood assay., Materials and Methods: Two dental implant systems with internal connections and the following material combinations at the implant-abutment interface (IAI) were used (implant material/abutment material): yttrium-stabilized tetragonal zirconium dioxide (Y-TZP)/polyetherketoneketone (PEKK), and titanium (Ti/Ti). Test implants were inoculated with lipopolysaccharide (LPS) and sealed and submerged in human whole blood. Untreated implants served as the control groups. Changes in gene expression levels of inflammatory markers indicating LPS leakage were assessed after 1, 8, and 24 hours using quantitative real-time polymerase chain reaction., Results: In the Y-TZP/PEKK test group, a significant influence of the implant system (P < .001) on increases in gene expression indicating leakage were detected after 8 hours for TLR-4 and after 24 hours for interleukin 1-β and nuclear factor kappa-light-chain-enhancer of activated B-cells (NF-κB), indicating microleakage of LPS at the IAI. In the Ti/Ti test group, differences in gene expression were found only for NF-κB after 8 hours., Conclusion: The internal hexalobe IAI of two-piece dental implants fabricated from Y-TZP and PEKK do not prevent LPS molecular microleakage.

Objectives: To investigate the chewing efficiency and oral health-related quality of life of edentulous patients wearing complete dentures, successively supported by one, two, and three implants in the mandible., Methods: Thirteen (13) edentulous patients of at least 50 years of age received three implants in the mandible. After a conventional submerged healing period, the central implant was uncovered and connected to the denture base using a stud attachment. Two months later, chewing efficacy was evaluated, and the two lateral implants were uncovered and connected to the denture base. The central retention element was replaced by a short healing abutment with no connection to the denture base. Chewing efficiency was evaluated two months later. Afterward, the healing abutment of the central implant was replaced by a stud attachment and again connected to the denture base. Two months later, chewing efficacy was evaluated again. Oral health-related quality of life (OHRQoL) was measured at each recall visit using the summary score of the oral health impact profile. For statistical analysis of chewing efficacy, the changes from baseline (with no implants) to one, two, and three implants were used and tested by analysis of variance with repeated mesurements., Results: Chewing efficacy clearly increased after implant loading, with a significant increase when two implants were loaded (p ≤ .05), compared to the chewing efficacy with no implants. OHRQoL also significantly improved after implant loading., Conclusions: Within the limitations of the present clinical trial regarding the number of patients, chewing efficacy as well OHRQoL of edentulous patients improve after implant placement in the mandible, irrespective of the number of implants. The best chewing efficacy was achieved with two implants., (© 2022 The Authors. Clinical Oral Implants Research published by John Wiley & Sons Ltd.)

Objectives: This study aimed to demonstrate the effect of treating titanium-implant surfaces with plasma from two different sources on wettability and initial single-cell adhesion of human osteoblasts and to investigate whether aging affects treatment outcomes., Methods: Titanium disks with sandblasted and acid-etched (SLA) surfaces were treated with atmospheric pressure plasma (APP) and low-pressure plasma (LPP). For wetting behavior of the specimens after plasma treatment, the water contact angle was measured. The single-cell detachment force and amount of work of detachment of human osteoblasts were determined with single-cell force spectroscopy (SCFS). To evaluate the aging effect in APP-treated specimens, SCFS was conducted 10 and 60 min after treatment., Results: Significantly higher hydrophilicity was observed in the APP and LPP treatment groups than in the control group, but no significant difference was observed between the APP and LPP groups. No significant difference in cell-detachment force or work of detachment was observed, and there were no significant differences according to the conditioning mechanisms and storage time., Significance: Conditioning of the titanium surfaces with APP or LPP was not a significant influencing factor in the initial adhesion of the osteoblasts., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Objectives: The knowledge about the influence of dental treatment on health-related quality of life (HRQoL) is still limited. The aim of this multicenter randomized controlled clinical trial was to assess the effect of stabilizing an existing complete denture, by means of a single mandibular implant, on HRQoL. Furthermore, the impact of the loading protocol, i.e., immediate or delayed loading, in edentulous patients was evaluated., Methods: One hundred fifty-eight participants aged 60-89 years were randomly assigned to study group A (immediate loading; n = 81) and to group B (delayed loading; n = 78). All participants received a single midline implant in the mandible. The implants were either immediately loaded (group A) or after a closed healing period of 3 months (group B) by connecting the existing mandibular complete dentures to ball attachments. HRQoL was assessed with the Short Form-36 questionnaire of health (SF-36) at baseline, 4 months, and 24 months after implant loading., Results: Improvement of HRQoL by means of a single implant-retained mandibular overdenture could not be demonstrated after 4 and 24 months of implant loading. Furthermore, the application of two different loading protocols did not influence HRQoL ratings of study participants., Conclusion: The loading protocol is not a factor, influencing HRQoL in patients treated by a single midline implant in the edentulous mandible., Clinical Relevance: A single midline implant in the edentulous mandible, stabilizing a mandibular complete denture, cannot be recommended for improving HRQoL.

Microleakage has been discussed as a major contributing factor for inflammatory reactions at the implant-abutment connection. In previous studies, the tightness against corpuscular bodies (viable bacteria) has been successfully investigated under static and dynamic conditions. The aim of this study was to investigate the tightness against endotoxins of two implant systems (AstraTech and Ankylos) with conical internal connections under static conditions. The inner parts of eight implants of each system were inoculated with endotoxin. Implants were screwed together with the respective abutments and stored under isostatic conditions in a supernatant of pyrogen-free water for 168 h. Supernatant samples were taken after 5 min, 24 h, 72 h, and 168 h, and endotoxin contamination was determined by the amebocyte-lysate test. Only one implant in the AstraTech group showed no sign of endotoxin contamination after 168 h, while the other implants showed contamination after varying storage times, respectively. The implants in the Ankylos group showed endotoxin contamination after only 5 min of storage in the supernatant solution. The tested internal conical implant-abutment connections appear to be unable to prevent endotoxin leakage. In average, Astra implants showed a higher tightness than Ankylos implants.

Purpose: Implant-supported dental prostheses are based on the principle of osseointegration, and the success of dental implantation depends on adequate formation of this intimate bone-to-implant contact. The application of heat during the drilling procedure leads to a rise in intraosseous temperature at the prospective implant site, which may result in various complications. The purpose of the present study was to compare the ability of thermocouples and infrared thermography to detect changes in intraosseous temperature during dental implant site preparation. Materials and Methods: Standardized bovine costae bone blocks were used to simulate the cortical bone of the human mandible. Steel implant form drills with a diameter of 3.0 mm were used. Two types of irrigation systems were used (external cooling only and combined internal and external cooling). Drilling was performed at a constant speed (1,200 rpm). Changes in intraosseous temperature were evaluated using Type T Cu-CuNi thermocouples and an infrared thermography camera system at contact pressures of 5 and 20 N. Results: Infrared thermography detected significantly greater increases in intraosseous temperature (ΔT) than thermocouples for all tested combinations of cooling system and contact pressure (P ≤ .0001). Conclusion: These results suggest that thermography more accurately reflects intraosseous temperature changes during implant site preparation than thermocouples. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to investigate the precision of mechanical torque wrenches used for implants in dental offices.Materials and Methods: Mechanical torque wrenches (n = 138) with two functional designs and made by three manufacturers were tested by three groups of investigators. Potential influences on accuracy were tested. Relative deviations from targeted torque values and the precision of recorded torque values were analyzed.Results: Most abutment screws were tightened too tightly rather than too weakly. Differences were apparent in the influence of the functional design of torque wrenches on their precision. No significant correlation between absolute frequency of use and relative deviation or precision was detected. Investigators with different levels of experience exhibited significantly different deviations from targeted torque values.Conclusions: Average deviation from intended torque values, and levels of imprecision, are evidently not major problems in implant prosthetics; however, high torque values are a cause for concern. [ABSTRACT FROM AUTHOR]

Purpose A single implant can be placed to retain an overdenture in the edentulous mandible. This study aimed at the development of Oral Health-related Quality of Life comparing immediate and delayed implant loading, i.e., loading after 3 months of submerged healing. Methods In a randomized controlled trial, 158 participants received a single mandibular implant in the midline. Quality of life was measured using the summary score of the German 49-item Oral Health Impact Profile at baseline, one month after implant placement (direct loading group) as well as one and four months after loading. Results Mean scores at baseline were comparable. Four months after implantation, a decrease of mean scores was recognized for both groups, indicating a significantly enhanced quality of life after treatment. When comparing the groups after both 1 and 4 months of loading, quality of life was insignificantly higher in the delayed loading group (1 month: 42.1 vs. 32.3; 4 months: 33.6 vs. 27.7). For immediate loading, an insignificant tendency to an earlier improvement was recognized (Δ 1 month-baseline : 9.7, compared to Δ 1 month-baseline : 6.4). Conclusions The single mandibular implant concept was associated with a positive impact on quality of life. However, no statistically significant influence of implant loading on quality of life was found. [ABSTRACT FROM AUTHOR]