The severity of human peri-implantitis lesions correlates with the level of submucosal microbial dysbiosis.

AIM: To cross-sectionally analyse the submucosal microbiome of peri-implantitis (PI) lesions at different severity levels. MATERIALS AND METHODS: Microbial signatures of 45 submucosal plaque samples from untreated PI lesions obtained from 30 non-smoking, systemically healthy subjects were assessed by 16s sequencing. Linear mixed models were used to identify taxa with differential abundance by probing depth, after correction for age, gender, and multiple samples per subject. Network analyses were performed to identify groups of taxa with mutual occurrence or exclusion. Subsequently, the effects of peri-implant probing depth on submucosal microbial dysbiosis were calculated using the microbial dysbiosis index. RESULTS: In total, we identified 337 different taxa in the submucosal microbiome of PI. Total abundance of 12 taxa correlated significantly with increasing probing depth; a significant relationship with lower probing depth was found for 16 taxa. Network analysis identified two mutually exclusive complexes associated with shallow pockets and deeper pockets, respectively. Deeper peri-implant pockets were associated with significantly increased dysbiosis. CONCLUSION: Increases in peri-implant pocket depth are associated with substantial changes in the submucosal microbiome and increasing levels of dysbiosis.

Correction: Pupil diameter differentiates expertise in dental radiography visual search.

[This corrects the article DOI: 10.1371/journal.pone.0223941.].

Pupil diameter differentiates expertise in dental radiography visual search.

Expert behavior is characterized by rapid information processing abilities, dependent on more structured schemata in long-term memory designated for their domain-specific tasks. From this understanding, expertise can effectively reduce cognitive load on a domain-specific task. However, certain tasks could still evoke different gradations of load even for an expert, e.g., when having to detect subtle anomalies in dental radiographs. Our aim was to measure pupil diameter response to anomalies of varying levels of difficulty in expert and student dentists' visual examination of panoramic radiographs. We found that students' pupil diameter dilated significantly from baseline compared to experts, but anomaly difficulty had no effect on pupillary response. In contrast, experts' pupil diameter responded to varying levels of anomaly difficulty, where more difficult anomalies evoked greater pupil dilation from baseline. Experts thus showed proportional pupillary response indicative of increasing cognitive load with increasingly difficult anomalies, whereas students showed pupillary response indicative of higher cognitive load for all anomalies when compared to experts.

Fixed Dental Prostheses and Single-Tooth Crowns Based on Ceria-Stabilized Tetragonal Zirconia/Alumina Nanocomposite Frameworks: Outcome After 2 Years in a Clinical Trial.

PURPOSE: This clinical trial tested bilayered restorations based on ceria-stabilized tetragonal zirconia/alumina frameworks veneered with feldspathic ceramic. MATERIALS AND METHODS: A total of 67 crowns and 40 fixed dental prostheses (FDPs) were luted in 57 patients with self-etching/self-adhesive composite resin cement. Dental status and integrity of restorations were evaluated at 2 weeks, 6 months, and then annually. RESULTS: A total of 66 crowns and 36 FDPs (88% posterior) survived for success rates of 93.4% for crowns and 89% for FDPs at 2 years. In particular, 11 cohesive ceramic chippings were observed in 5 crowns and 6 FDPs. CONCLUSION: The material allows excellent marginal adaptation. Susceptibility to veneering failures might be due to framework design and the necessities of esthetics.

Improving CT-Based PET Attenuation Correction in the Vicinity of Metal Implants by an Iterative Metal Artifact Reduction Algorithm of CT Data and Its Comparison to Dual-Energy-Based Strategies: A Phantom Study.

OBJECTIVE: The aim of this study was to evaluate the potential of iterative metal artifact reduction (IMAR) for the improvement of computed tomography (CT)-based position emission tomography (PET) attenuation correction in the vicinity of metal implants and compare it with dual-energy-based metal artifact reduction strategies. METHODS: A dedicated dental phantom was constructed consisting of a cylindrical tube filled with [18-F]FDG solution (5300 mL and 50.9 MBq) containing 2 artificial jaws with 1 nonprecious alloy fixed dental prosthesis and 3 single tooth crowns in the lower jaw.Computed tomography measurements of the phantom were acquired on a stand-alone dual-energy CT scanner equipped with IMAR capabilities. A series of 24 CT data sets were obtained using different scan parameters and monoenergetic extrapolation of dual-energy CT acquisitions with and without IMAR reconstruction.Position emission tomography measurements of the phantom were performed on a state-of-art PET/CT scanner. Position emission tomography data were reconstructed using all 24 previously acquired CT data sets.Relative errors in the quantification of activity concentrations using the different CT scanning and reconstruction parameters were quantified by placement of regions of interest within the phantom. RESULTS: Metal artifacts of different extent were observed in all CT data sets. A marked reduction in CT metal artifacts was observed using IMAR. In general, activity concentrations were overestimated/underestimated in areas of high/low-density metal artifacts, respectively.Relative errors in PET quantification ranged between -71% and +70% without IMAR. Using IMAR, these errors were reduced to a range between -40% and +12%. Averaged absolute values of relative PET quantification errors were 27% and 7% without and with the use of IMAR (P < 0.001), respectively. Iterative metal artifact reduction was superior compared with dual-energy-based metal artifact reduction strategies, and the combination of both strategies did not result in further significant improvement of PET quantification. CONCLUSIONS: The use of IMAR in PET/CT is a promising approach for markedly improving image quality and PET quantification in the vicinity of metal implants. Further clinical studies are necessary to assess the clinical performance of this algorithm in patients.

Zirconia-Based Anterior Resin-Bonded Single-Retainer Cantilever Fixed Dental Prostheses: A 15- to 61-Month Follow-Up.

PURPOSE: A total of 24 zirconia-based single tooth-retained restorations inserted in 18 patients were followed up for 15 to 61 months (mean: 35 months). MATERIALS AND METHODS: Recall consisted of dental and hygiene status as well as quality assessment and check for occlusal relationship. One patient was lost to follow-up. In the incuded patients, 15 central incisors, 3 canines, and 5 lateral incisors replaced 16 lateral incisors and 7 central incisors, mostly in the maxilla (n = 17). RESULTS: One retainer debonded, two pontics experienced incisal chip-offs, and one patient showed an orthodontic relapse. The success rate was estimated at 82.4%, with 100% survival at 36 months. CONCLUSION: Technical protocol and occlusal protection are crucial.

The performance of zirconium dioxide crowns: a clinical follow-up.

Thirty-two patients who had been treated with 71 computer-aided design/computer-assisted manufacture-fabricated Cercon crowns were followed to assess clinical performance by time-to-event analysis. Clinical examinations consisted of a complete dental and oral hygiene examination and a quality assessment by modified California Dental Association criteria. Four patients (6 crowns) were lost to follow-up; another 11 crowns had to be excluded from evaluation for comparability reasons. Six of 54 evaluated crowns experienced complications (P(C) = 11.1%) throughout a mean observation time of 21 months. Survival was estimated at 0.98 over 24 months. The good overall clinical performance was affected predominantly by technical complications of the veneering ceramic (P(TC) = 9.3%).