Tag: pubmed

Int J Oral Maxillofac Implants. 2022 Nov-Dec;37(2):356-364. doi: 10.11607/jomi.9022.

ABSTRACT

PURPOSE: To determine clinical parameters, histologic features, and radiographic linear bone width changes of regenerated bone using different biomaterials for ridge preservation following tooth extraction.

MATERIALS AND METHODS: For this pilot study, five patients were grafted with anorganic bovine bone and collagen plus recombinant human platelet-derived growth factor-BB (rhPDGF-BB), five patients were grafted with anorganic bovine bone and collagen alone, and five patients did not receive any biomaterial (control) after tooth extraction. Clinical, histologic, and radiographic evaluations were carried out 4 months postextraction.

RESULTS: Differences in terms of buccolingual width were found when comparing the control group to the group grafted with anorganic bovine bone and collagen plus rhPDGF-BB (P = .012). No statistical differences were observed between the groups in terms of mineralized or nonmineralized tissue formation or in terms of the number of osteoblasts or osteocytes per mm2 after 4 months of healing. Interestingly, the number of vessels in the grafted area was found to be significantly different among the three groups (P = .005). The number of Musashi-1 positive cells was also different among groups, both in the mineralized and the nonmineralized areas of the grafted bone (P = .024 and .005, respectively).

CONCLUSION: Anorganic bovine bone with bovine collagen is an efficient biomaterial to avoid postextraction resorption of the alveolar ridge. The addition of rhPDGF-BB appears to improve the biologic features of the newly formed bone and decrease bone resorption; further studies are needed for confirmation.

PMID:35476865 | DOI:10.11607/jomi.9022

Int J Oral Maxillofac Implants. 2022 Mar-Apr;37(2):339-345. doi: 10.11607/jomi.9329.

ABSTRACT

PURPOSE: To evaluate the use of a new resin metal opaquer on the surface of titanium abutments, in combination with two luting agents, and its effect on the retentive strength of implant-supported zirconia copings.

MATERIALS AND METHODS: Sixty customized titanium abutments were designed and fabricated with virtual design software and a milling machine. Thirty abutment specimens were coated with metal opaquers, and the others were not coated. Then, the titanium abutments were fitted into the implant analogs, and the abutment-implant analog complexes were embedded in acrylic resin blocks. Sixty CAD/CAM-fabricated zirconia copings were seated on the abutments and secured with glassionomer cement or self-adhesive resin cement. The specimens were stored in 100% humidity for 1 hour and artificial saliva for 23 hours at 37°C before thermocycling for 5,000 cycles of 5°C to 55°C with a 30-second dwell time. The retentive strength was measured using a pull-out test with a universal testing machine. The dislodgment forces were statistically analyzed via two-way analysis of variance (ANOVA). The failure modes were evaluated and categorized by examining the fracture surface.

RESULTS: The metal opaquer material had a significant negative effect on retention of zirconia copings. The nonopaquer titanium abutments showed significantly (P < .05) higher retentive strength than the metal opaquer abutments. Comparing the cements, the retentive strength values of self-adhesive resin cement were significantly higher than those of glass-ionomer cement. The metal opaquer groups exhibited mostly mixed-type failures, a combination of adhesive failures and cohesive failures, whereas the nonopaquer groups showed mostly adhesive-type failures.

CONCLUSION: The titanium abutments coated with the new metal opaquer material resulted in a reduction of retentive strength. Self-adhesive resin cements exhibited significantly higher retention than glass-ionomer cements.

PMID:35476863 | DOI:10.11607/jomi.9329

Int J Oral Maxillofac Implants. 2022 Mar-Apr;37(2):329-338. doi: 10.11607/jomi.9374.

ABSTRACT

PURPOSE: The scarce standard therapeutic protocols for the management of peri-implant diseases results in the empirical application of therapeutic modalities. The objective of this study was to carry out a survey to analyze the therapeutic trends of professionals with different academic backgrounds and levels of expertise.

MATERIALS AND METHODS: An exploratory cross-sectional internet-based study survey of board-certified members of the American Academy of Periodontology (AAP) and the European Federation of Periodontology (EFP) was conducted. To assess the therapeutic trends, four clinical vignettes representing different scenarios of peri-implant biologic complications were provided to the participants. Differences in practice patterns were determined using chi-square test and Student t test or analysis of variance (ANOVA) test for qualitative variables.

RESULTS: A total of 268 members of the AAP and EFP completed the survey. A significant difference in preferred treatment plan was found between EFP and AAP periodontists, resective therapy being the treatment of choice by the majority of the former (41.2%) and regenerative therapy by the latter (48.9%; P < .001). Overall, 48.1% of experts did not consider any intervention for the management of mucositis. Antibiotic prescriptions differed among groups, with statistical significance in each clinical case, and the explantation criteria were inconsistent and differed significantly among groups.

CONCLUSION: Substantial variations exist concerning the decision-making to manage peri-implant diseases and conditions.

PMID:35476862 | DOI:10.11607/jomi.9374

Int J Oral Maxillofac Implants. 2022 Mar-Apr;37(2):e41-e49. doi: 10.11607/jomi.9197.

ABSTRACT

PURPOSE: Titanium and zirconium wear are discussed in the literature as contributing factors for mechanical complications. The purpose of this study was to evaluate if current implant designs present visible clinical evidence of surface damage after insertion and removal in dense bone and if these changes are comparable in titanium and zirconia implants.

MATERIALS AND METHODS: For this experimental in vitro and pilot study, four implant systems were evaluated. Astra Tech Implants (Dentsply Sirona), Nobel Biocare Implants (Nobel Biocare), Straumann Implants (Institut Straumann), and Zeramex Implants (Dentalpoint). Six implants of each group with similar lengths (between 10 and 11 mm) and diameters (between 4.0 and 4.5 mm) were used. Protocols for implant bed preparations in dense bovine bone disks represented type II bone density. The implants were inserted and removed to evaluate the changes experienced by their surfaces using a magnification compatible with 5× magnification of the clinical setting. The presence or absence of damage and type of damage were evaluated at the coronal, middle, and apical regions at higher magnification. The Cochran Q test for binary dichotomous samples was used for statistical comparisons.

RESULTS: All the groups showed surface changes; titanium implants showed abrasion at the threads’ flanks, and zirconia implants showed microfractures at the tip of the threads.

CONCLUSION: Due to the insertion and removal of titanium and zirconia implants in dense bone, the flanks and tips of the implant threads will develop visible surface damage.

PMID:35476861 | DOI:10.11607/jomi.9197

Int J Oral Maxillofac Implants. 2022 Mar-Apr;37(2):320-327. doi: 10.11607/jomi.9406.

ABSTRACT

PURPOSE: To determine the effect of 0.7- and 2.4-mm transmucosal abutment height titanium bases on the crestal bone stability and peri-implant soft tissue condition of bone-level implants with platform switching in patients with vertically thick soft tissues.

MATERIALS AND METHODS: Sixty bone-level platform-switched implants were placed in the molar and premolar regions of both arches in 60 patients. All epicrestally inserted nonsubmerged implants had a 4.1-mm diameter and, after osteointegration, were randomly allocated into two groups: (1) the short group, with a titanium base of 0.7-mm transmucosal abutment height, and (2) the high group with a 2.4-mm height. Monolithic zirconia restorations were fabricated for all implants. Parallel intraoral radiographs were obtained after the delivery of restorations (T1) and after 1 year (T2). Crestal bone levels and peri-implant soft tissue conditions were calculated for each implant. The significance level was set at α = .05.

RESULTS: After 1 year, 55 patients were evaluated, with a mean bone loss of 0.6 ± 0.51 mm (median: 0.71, range: 0 to 2.09 mm) in the short group (23 patients) and 0.45 ± 0.59 mm (median: 0.65, range: 0 to 2.12 mm) in the high group (22 patients), showing no significant difference between groups (P = .168). A significant increase in marginal bone height was noted between the T1 and T2 time points in the short and high (P = .029 and .001, respectively) groups. The peri-implant soft tissue health parameters did not show statistically significant differences.

CONCLUSION: Crestal bone stability after 1 year of follow-up around epicrestally placed platform-switched implants is not influenced by transmucosal abutment height, if the vertical soft tissue thickness is ≥ 3 mm.

PMID:35476860 | DOI:10.11607/jomi.9406

Int J Oral Maxillofac Implants. 2022 Mar-Apr;37(2):250-269. doi: 10.11607/jomi.9286.

ABSTRACT

PURPOSE: The exposure of nonresorbable membranes following alveolar bone augmentation is one of the most frequently occurring complications. This review aimed to investigate the treatments that can be adopted to manage the exposure of polytetrafluoroethylene-based membranes (PTFE-ms) and titanium meshes (TMs) and their outcomes.

MATERIALS AND METHODS: Two independent reviewers electronically and manually searched the EMBASE, PubMed/MEDLINE, Scopus, and Cochrane bibliographic databases to retrieve pertinent articles available between January 2000 and March 2021. Only human studies describing the type of treatment and the soft tissue outcome following exposure of PTFE-ms or TMs were included.

RESULTS: Overall, 11 articles in the PTFE-ms group and 24 in the TM group were included for data analysis. Results indicated that, in both groups, two distinct therapeutic strategies are mostly applied in case of exposure, namely, pharmacologic and mechanical treatments. Other options have been identified seldomly. Statistically significant evidence of an association between the type of barrier membrane and the exposure rate (28.7% vs 38.5% for TMs and PTFE-ms, respectively; P = .019) and between the type of exposed device and the treatment outcome in terms of removal rate following therapy (11.9% and 44.4% for TMs and PTFE-ms, respectively; P < .001) was noted.

CONCLUSION: In both groups, chlorhexidine applications and meticulous plaque control may lead to improved healing conditions after exposure. Surgical removal of the exposed portion can be considered to promote secondary intention healing. The beneficial effects of systemic antibiotics could not be demonstrated in the management of the exposure but should be evaluated in case of graft infection.

PMID:35476854 | DOI:10.11607/jomi.9286

PLoS One. 2022 Apr 27;17(4):e0266060. doi: 10.1371/journal.pone.0266060. eCollection 2022.

ABSTRACT

The reason for the existence of adversarial samples is still barely understood. Here, we explore the transferability of learned features to Out-of-Distribution (OoD) classes. We do this by assessing neural networks’ capability to encode the existing features, revealing an intriguing connection with adversarial attacks and defences. The principal idea is that, “if an algorithm learns rich features, such features should represent Out-of-Distribution classes as a combination of previously learned In-Distribution (ID) classes”. This is because OoD classes usually share several regular features with ID classes, given that the features learned are general enough. We further introduce two metrics to assess the transferred features representing OoD classes. One is based on inter-cluster validation techniques, while the other captures the influence of a class over learned features. Experiments suggest that several adversarial defences decrease the attack accuracy of some attacks and improve the transferability-of-features as measured by our metrics. Experiments also reveal a relationship between the proposed metrics and adversarial attacks (a high Pearson correlation coefficient and low p-value). Further, statistical tests suggest that several adversarial defences, in general, significantly improve transferability. Our tests suggests that models having a higher transferability-of-features have generally higher robustness against adversarial attacks. Thus, the experiments suggest that the objectives of adversarial machine learning might be much closer to domain transfer learning, as previously thought.

PMID:35476838 | DOI:10.1371/journal.pone.0266060

PLoS One. 2022 Apr 27;17(4):e0267495. doi: 10.1371/journal.pone.0267495. eCollection 2022.

ABSTRACT

BACKGROUND: Previous studies proposed possible applications of spectral-domain optical coherence tomography (SD-OCT) measurements in prognosticating pathologies observed in overweight/obesity, including ocular, vascular, and neurologic consequences. Therefore, we conducted a systematic review and meta-analysis to investigate the changes in the in SD-OCT measurements of the patients with higher body mass index (BMI) compared to normal weight individuals.

MATERIALS AND METHODS: We conducted a systematic search on PubMed, Scopus, and Embase. The search results underwent two-phase title/abstract and full-text screenings. We then analyzed SD-OCT measurements differences in patients with high BMI and controls, and performed meta-regression, sub-group analysis, quality assessment, and publication bias assessment. The measurements included macular thickness, cup to disc ratio, ganglion cell-inner plexiform layer (GC-IPL) and its sub-sectors, RNFL and peripapillary RNFL (pRNFL) and their sub-layers, and choroidal thickness and its sub-sectors.

RESULTS: 19 studies were included in this meta-analysis accounting for 1813 individuals, 989 cases and 824 controls. There was an overall trend towards decreased thickness in high BMI patients, but only two measurements reached statistical significance: temporal retinal nerve fiber layer (RNFL) (Standardized mean difference (SMD): -0.33, 95% confidence interval (CI): -0.53 to -0.14, p<0.01) and the choroidal region 1.0 mm nasal to fovea (SMD: -0.38, 95% CI: -0.60 to -0.16, p<0.01).

CONCLUSION: Some ocular layers are thinner in patients with higher BMI than the controls. These SD-OCT measurements might correlate with adverse events related to increased body weight and have prognostic abilities. As SD-OCT is a robust, rapid and non-invasive tool, future guidelines and studies are needed to evaluate the possibility of their integration into care of the patients with obesity.

PMID:35476846 | DOI:10.1371/journal.pone.0267495

PLoS One. 2022 Apr 27;17(4):e0267578. doi: 10.1371/journal.pone.0267578. eCollection 2022.

ABSTRACT

OBJECTIVE: To assess the levels of stress, burnout, and job satisfaction among mental healthcare professionals in Jeddah City, Saudi Arabia.

METHODS: A cross-sectional study was conducted on mental healthcare professionals in Jeddah between January 2017 and October 2018. Sociodemographic characteristics and levels of stress, burnout, and job satisfaction were assessed using the Perceived Stress Scale-14 (PSS-14), Maslach Burnout Inventory (MBI), and Job Satisfaction Scale (JSS). Descriptive statistics were used. Independent sample t-test, one-way ANOVA, Mann-Whitney, and Kruskal-Wallis tests were conducted to assess for effects of demographic variables on the perceived stress score, emotional exhaustion (EE) score, depersonalization (DP) score, professional accomplishment (PA) score, and the job satisfaction score (JSS).

RESULTS: A total of 107 participants were included (50.5% men; 49.5% women) with response rate of 79.2%. Prevalence of stress was 56.1%. High levels of emotional exhaustion and depersonalization were present among 41 (38.3%) and 26 (24.3%) of the respondents, respectively, while high score of low personal accomplishment were present among 61 (57%) respondents. In terms of job satisfaction, 25 (23.4%) were satisfied and 74 (69.2%) were indecisive. Male participants’ emotional exhaustion score (27±12) was significantly higher than females (22 ±10), (t(105) = 1.99, p-value = 0.049). Also, participants with a monthly income above SR 20,000 had significantly higher total job satisfaction (p-value = 0.041).

CONCLUSIONS: Our findings suggest rates of stress and burnout among mental health professionals that warrant attention, with less than one-quarter of the participants being satisfied with their jobs. Further studies are needed to expand the findings and to explore the contributing factors. Additionally, interventions should be established by authorities to address the increasing rates of stress and burnout.

PMID:35476815 | DOI:10.1371/journal.pone.0267578

PLoS One. 2022 Apr 27;17(4):e0267291. doi: 10.1371/journal.pone.0267291. eCollection 2022.

ABSTRACT

BACKGROUND: MicroRNAs (miRNAs) are frequently deregulated in various types of cancer. While antisense oligonucleotides are used to block oncomiRs, delivery of tumour-suppressive miRNAs holds great potential as a potent anti-cancer strategy. Here, we aim to determine, and functionally analyse, miRNAs that are lowly expressed in various types of tumour but abundantly expressed in multiple normal tissues.

METHODS: The miRNA sequencing data of 14 cancer types were downloaded from the TCGA dataset. Significant differences in miRNA expression between tumor and normal samples were calculated using limma package (R programming). An adjusted p value < 0.05 was used to compare normal versus tumor miRNA expression profiles. The predicted gene targets were obtained using TargetScan, miRanda, and miRDB and then subjected to gene ontology analysis using Enrichr. Only GO terms with an adjusted p < 0.05 were considered statistically significant. All data from wet-lab experiments (cell viability assays and flow cytometry) were expressed as means ± SEM, and their differences were analyzed using GraphPad Prism software (Student’s t test, p < 0.05).

RESULTS: By compiling all publicly available miRNA profiling data from The Cancer Genome Atlas (TCGA) Pan-Cancer Project, we reveal a small set of tumour-suppressing miRNAs (which we designate as ‘normomiRs’) that are highly expressed in 14 types of normal tissues but poorly expressed in corresponding tumour tissues. Interestingly, muscle-enriched miRNAs (e.g. miR-133a/b and miR-206) and miRNAs from DLK1-DIO3 locus (e.g. miR-381 and miR-411) constitute a large fraction of the normomiRs. Moreover, we define that the CCCGU motif is absent in the oncomiRs’ seed sequences but present in a fraction of tumour-suppressive miRNAs. Finally, the gain of function of candidate normomiRs across several cancer cell types indicates that miR-206 and miR-381 exert the most potent inhibition on multiple cancer types in vitro.

CONCLUSION: Our results reveal a pan-cancer set of tumour-suppressing miRNAs and highlight the potential of miRNA-replacement therapies for targeting multiple types of tumour.

PMID:35476804 | DOI:10.1371/journal.pone.0267291