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Objectives: To measure the efficiency of three cleaning modalities on two implant designs with similar diameters but different thread depths as well as the presence of titanium particles., Methods: Sixty dyed implants (30 × 4.8 apically tapered (ATAP) and 30 × 5.0 fully tapered (FTAP)) were fixed in plastic models. The horizontal bone defects were surrounded with porcine soft tissue. Three instrumentation modalities were used to clean for 150 s: Curette (CUR), ultrasonic scaler (US), and air powder waterjet device (APWJ) with erythritol powder. Afterward, implants were photographed and scanning electron microscopic (SEM) images were taken. Titanium in the soft tissues was quantified in dissolved samples and histologically confirmed., Results: For ATAP and FTAP implants, the percentage of the cleaned surface was 26.4 ± 3.0 and 17.1 ± 2.4% for CUR, 33.7 ± 3.8% and 28.1 ± 2.3% for US, and 45.5 ± 4.1% and 24.7 ± 3.8% for APWJ, respectively. SEM images showed significant implant surface changes, especially after instrumentation with CUR and US, whereas APWJ had little to no effect. Most titanium residues were found after cleaning ATAP implants with CUR (152.0 ± 75.5), followed by US (89.5 ± 73.8) and APWJ (0.3 ± 0.8). For the FTAP implants, respective values accounted for 129.5 ± 58.6 μg and 67.0 ± 14.4 μg for CUR and US, respectively. No titanium residues were detected on ATAP with APWJ., Conclusion: Based on in vitro data, erythritol-powered APWJ still appears to be the most efficient and gentle cleaning method. All three instruments, however, were found to have unprocessed areas depending on different implant designs, hence, clinical relevance for non-surgical approaches remains challenging and warrants further improvement., (© 2023 The Authors. Clinical Oral Implants Research published by John Wiley & Sons Ltd.)

Objectives: To assess the mechanical stability of implants after implantoplasty and thermocyclic loading, the residual thickness of the instrumented areas and neighbouring tooth injury due to implantoplasty., Materials and Methods: Using a phantom head simulator and maxillary model implants were subjected to an implantoplasty procedure. Thirty implants were randomly assigned to receive one of three instrumentation sequences. After instrumentation, injury on neighbouring teeth was assessed. Instrumented implants and non-instrumented controls were subjected to 1.2 million cycles of thermo-mechanical loading in a chewing machine. Afterwards, maximum fracture load for all implants and an additional five pristine control implants was tested., Results: Generally, damage of neighbour teeth was a frequent finding (33 ± 56% of all cases) with considerable inter-group differences. No considerable inter-group difference for the residual implant thickness was found for different areas assessed. No implant fractured during cyclic loading. Fracture load was reduced after cyclic loading of uninstrumented implants from 2,724 ± 70 N to 2,299 ± 127 N, and after implantoplasty to 1,737 ± 165 N, while no effect by the instrumentation sequence could be observed., Conclusions: Both implantoplasty and cyclic loading were shown to reduce the implants' maximum bending strength. Cyclic loading in a laboratory masticator, simulating a five-year equivalent of chewing, did not result in fractured implants. Since neighbouring tooth injury was assessed often, care should be taken with the selection of suitable instruments., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objective: To follow-up the radiographic changes in peri-implant bone of short (6 mm, test group) and long (10 mm, control group) single-unit implants five years after loading., Materials and Methods: Forty-three implants of the test and 44 implants of the control group could be reassessed from 96 originally included implants. Standardized areas of interest (AOI) were defined in the peri-implant bone at pre-defined locations at mid-length on both sides of the implants, and at the apex. An arbitrary mean grey scale value (GSV) was calculated for the AOI after brightness calibration of the radiographs. Changes for GSV were calculated and tested for possible inter- and intra-group differences using the Mann-Whitney and Wilcoxon tests., Results: The calculated intra-group differences between baseline and 5 years in the test group accounted for 2.4 ± 19.6 (i.e. slight brightening) and -6.2 ± 20.2 for the control group (i.e. slight shading), which resulted in a statistically significant difference in GSV change (p < .05). Crown-to-implant ratio was the only parameter showing an effect on GSV change (p = .001)., Conclusions: Assessing conventional radiographs, longer implants showed a slightly stronger change of radiopacity of the peri-implant bone (slight loss of density) than short ones (slightly enhanced density) after five years of loading., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objective: To test the accuracy of measurement of interproximal peri-implant bone defects at titanium (Ti) and zirconium dioxide (ZrO 2 ) implants by digital periapical radiography (PR) and cone beam computed tomography (CBCT)., Material and Methods: A total of 18 models, each containing one Ti and one ZrO 2 implant, were cast in dental stone. Six models each were allocated to following defect groups: A-no peri-implant defect, B-1 mm width defect, C-1.5 mm width defect. The defect width was measured with a digital sliding caliper. Subsequently, the models were scanned by means of PR and CBCT. Three examiners assessed the defect width on PR and CBCT. Wilcoxon signed-rank test and Wilcoxon rank sum test were applied to detect differences between imaging techniques and implant types., Results: For PR, the deviation of the defect width measurement (mm) for groups A, B, and C amounted to 0.01 ± 0.03, -0.02 ± 0.06, and -0.00 ± 0.04 at Ti and 0.05 ± 0.02, 0.01 ± 0.03, and 0.09 ± 0.03 at ZrO 2 implants. The corresponding values (mm) for CBCT reached 0.10 ± 0.11, 0.26 ± 0.05, and 0.24 ± 0.08 at Ti and 1.07 ± 0.06, 0.64 ± 0.37, and 0.54 ± 0.17 at ZrO 2 implants. Except for Ti with defect A, measurements in PR were significantly more accurate in comparison to CBCT (p ≤ 0.05). Both methods generally yielded more accurate measurements for Ti than for ZrO 2 ., Conclusions: The assessment of interproximal peri-implant defect width at Ti and ZrO 2 implants was more accurate in PR in comparison to CBCT. Measurements in CBCT always led to an overestimation of the defect width, reaching clinical relevance for ZrO 2 implants., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objectives: To assess the cleaning potential of commonly used implant debridement methods, simulating non-surgical peri-implantitis therapy in vitro., Materials and Methods: One-hundred-and-eighty dental implants were ink-stained and mounted in combined soft and hard tissue models, representing peri-implantitis defects with angulations of 30, 60, and 90° covered by a custom-made artificial mucosa. Implants were treated by a dental school graduate and a board-certified periodontist for 120 s with following instruments: Gracey curette, ultrasonic scaler, and an air powder abrasive device with a nozzle for sub-mucosal use utilizing glycine powder. All procedures were repeated 10 times for each instrumentation and defect morphology respectively. Images of the implant surface were taken. Areas with color remnants were planimetrically determined and their cumulative surface area was calculated. Results were tested for statistical differences using two-way anova and Bonferroni correction. Micro-morphologic surface changes were analyzed on scanning electron microscope (SEM) images., Results: The areas of uncleaned surfaces (%, mean ± standard deviations) for curettes, ultrasonic tips, and air abrasion accounted for 74.70 ± 4.89%, 66.95 ± 8.69% and 33.87 ± 12.59% respectively. The air powder abrasive device showed significantly better results for all defect angulations (P < 0.0001). SEM evaluation displayed considerable surface alterations after instrumentation with Gracey curettes and ultrasonic devices, whereas glycine powder did not result in any surface alterations., Conclusion: A complete surface cleaning could not be achieved regardless of the instrumentation method applied. The air powder abrasive device showed a superior cleaning potential for all defect angulations with better results at wide defects., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objectives: The microbial composition of peri-implantitis-associated biofilms may resemble that of periodontitis, with some distinctive differences, as identified by various conventional or molecular detection methods. Yet, the complete microbiome of peri-implantitis awaits further characterization. The present clinical study was undertaken with the aim to investigate the association of Spirochaetes, and the more recently identified phylum Synergistetes, with peri-implantitis., Materials and Methods: Submucosal biofilms were obtained from single sites of patients with peri-implantitis (n = 43) or individuals with peri-implant health (n = 41). The samples were analysed by fluorescence in situ hybridization (FISH) and epifluorescence microscopy, using 16S rRNA-based oligonucleotide probes for Synergistetes cluster A, subclusters A1 and A2, and Treponema groups I-III and IV., Results: Treponema group IV was barely detectable, whereas Treponema groups I-III were detected at low prevalence in health, but their prevalence and numbers were significantly increased in peri-implantitis by 48% and 2.4-log, respectively. Synergistetes cluster A was detected in half of the healthy sites, and its prevalence and numbers were significantly increased in peri-implantitis by 30% and 2.5-log, respectively. No quantitative differences were found between Synergistetes subclusters A1 and A2 numbers, as both increased by 2.8-log. Synergistetes cluster A displayed strong correlations with several clinical peri-implant parameters, but Treponema groups I-III only with probing pocket depth., Conclusion: The present clinical cross-sectional study demonstrates that Spriochaetes of the Treponema groups I-III, but not group IV, and Synergistetes of the cluster A are highly associated with peri-implantitis. Synergistetes cluster A appears to display a stronger association with peri-implantitis than Spirochaetes., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objectives: To investigate the cleaning efficacy of a mechanical and a hydrodynamic homecare device on biofilm-coated titanium surfaces with and without chlorhexidine., Material and Methods: Six-species biofilms were grown on 108 SLA-titanium discs, which were cleaned as follows: sonic toothbrush alone (i) or in combination with either a 0.2% chlorhexidine (ii) or a placebo gel (iii) and oral irrigator (hydrodynamic action) with water (iv) or combined with 0.2% chlorhexidine solution (v). Untreated samples served as control (vi). Biofilms were then harvested either immediately after treatment (study part A) or after a regrowth phase of 24 h (study part B) and colony-forming units (CFU) were assessed. Results were analysed using Whitney U-tests between the treatment groups. After the Bonferroni correction, the significance level was set at α = 0.0033., Results: The median CFU counts directly after instrumentation accounted - in ascending order (P-values in comparison with the control group A6 were <0.001 for all groups except for A3: P = 0.014) - 2.0E1 (A5), 1.1E5 (A4), 3.6E5 (A2), 3.3E5 (A1) and 6.8E6 (A3), respectively. The untreated control group showed the highest CFU counts: 1.8E7 (A6). After regrowth, the following CFU counts were measured in ascending order (all P-values <0.001 when compared to the control group B6 = 2.0E8): 1.6E2 (B5), 1.9E5 (B2), 1.4E7 (B4), 3.1E7 (B1) and 3.9E7 (B3)., Conclusions: An oral irrigator combined with 0.2% chlorhexidine is effective in reducing biofilms attached to rough titanium surfaces immediately after cleaning. Following a regrowth phase of 24 h, micro-organisms could be equally effective removed with a sonic toothbrush combined with 0.2% chlorhexidine and an oral irrigator with 0.2% chlorhexidine., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objectives: To assess the cleaning potential of three different instrumentation methods commonly used for implant surface decontamination in vitro, using a bone defect-simulating model., Materials and Methods: Dental implants were stained with indelible ink and mounted in resin models, which represented standardized peri-implantitis defects with different bone defect angulations (30, 60 and 90°). Cleaning procedures were performed by either an experienced dental hygienist or a 2nd-year postgraduate student. The treatment was repeated 20 times for each instrumentation, that is, with a Gracey curette, an ultrasonic device and an air powder abrasive device (PAD) with glycine powder. After each run, implants were removed and images were taken to detect color remnants in order to measure planimetrically the cumulative uncleaned surface area. SEM images were taken to assess micromorphologic surface changes (magnification 10,000 ×). Results were tested for statistical differences using two-way ANOVA and Bonferroni correction., Results: The areas of uncleaned surfaces (%, mean ± standard deviations) for curettes, ultrasonic tips, and airflow accounted for 24.1 ± 4.8%, 18.5 ± 3.8%, and 11.3 ± 5.4%, respectively. These results were statistically significantly different (P < 0.0001). The cleaning potential of the airflow device increased with wider defects. SEM evaluation displayed distinct surface alterations after instrumentation with steel tips, whereas glycine powder instrumentation had only a minute effect on the surface topography., Conclusion: Within the limitations of the present in vitro model, airflow devices using glycine powders seem to constitute an efficient therapeutic option for the debridement of implants in peri-implantitis defects. Still, some uncleaned areas remained. In wide defects, differences between instruments are more accentuated., (© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objectives: The study aimed to assess the accessibility of a glycine powder blasting device to implant surfaces in models imitating different peri-implantitis defects. The null hypothesis was that the device allows for complete surface decontamination in all defect types., Materials and Methods: Eighteen implants were dip-coated and placed in resin blocks with different defect morphologies. Vertical bone angulations of 90°, 60°, 30° and 15° were chosen and the implants were treated for 10 s using an air-flow device employing glycine powder. Once removed, photographs from the implants were taken in three directions: perpendicularly (90°) to the implant axis and with an angulation of 60° and 120°, the latter ones to assess the coronal and apical thread areas. The area with residual color represented areas, which were not accessible to the powder. This area was planimetrically assessed. Medians and inter-quartile ranges (IQR) of the percentage of uncleaned surfaces were calculated and nonparametric paired and unpaired statistical analyses were performed., Results: The median percentages (IQR in brackets) of uncleaned areas in the 90°, 60°, 30° and 15° defects were of 3%(A) (6), 8%(A) (4), 24%(B) (8), and 51%(C) (13), respectively (different superscript capital letters represent statistically significant differences; P < 0.0001). The upper aspects of the threads (coronal faces) were significantly better cleaned than the lower ones (P < 0.001). This finding was more pronounced in narrower defects., Conclusion: Although a complete surface decontamination could not be performed in any of the defects, the biggest part of the surface could be cleaned in the larger defects. Especially in narrow defects and under the threads, residually stained areas remain on the implant surfaces., (© 2012 John Wiley & Sons A/S.)