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This study aims at the controllability of acoustically manipulated non-contact aggregation of bi-particle. Based on the acoustic wave radiation model of the transducer and the acoustic wave interference theory, the mathematical model between the spatial levitation point and the phase of the phased array ultrasonic array unit is established. A double-sided phased array test system was developed and the phase calculation algorithm for independently manipulating bi-particle was optimized. The algorithm is capable of independently distributing the energy applied to each levitation point. Through simulation and experiment, the horizontally aggregation characteristics of two levitated particles are investigated, and a interesting relationship between particles aggregation and standing wave phase difference is revealed, which follows the law of "attraction in the same phase but repulsion in the opposite phase". By adjusting the tilt angle of the standing wave acoustic trap, the critical distance when particles to accelerate and collision is sharply reduced from 1.5λ to 0.5λ, which provides a new perspective and potential application path for acoustic manipulation technology.

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Synthetic aperture radar (SAR) image registration is an important process in many applications, such as image stitching and remote sensing surveillance. The registration accuracy is commonly affected by the presence of speckle noise in SAR images. When speckle noise is intense, the number of image features acquired by single-feature-based methods is insufficient. An SAR image registration method that combines nonlinear diffusion filtering, Hessian features and edge points is proposed in this paper to reduce speckle noise and obtain more image features. The proposed method uses the infinite symmetric exponential filter (ISEF) for image pre-processing and nonlinear diffusion filtering for scale-space construction. These measures can remove speckle noise from SAR images while preserving image edges. Hessian features and edge points are also employed as image features to optimize the utilization of feature information. Experiments with different noise levels, geometric transformations and image scenes demonstrate that the proposed method effectively improves the accuracy of SAR image registration compared with the SIFT-OCT, SAR-SIFT, Harris-SIFT, NF-Hessian and KAZE-SAR algorithms.

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China has a great wealth of lake resources over a great spatial extent and these lakes are highly sensitive to climate changes through their heat and water budgets. However, little is known about the changes in lake surface water temperature (LSWT) across China under the climate warming conditions over the past few decades. In this study, MODIS land surface temperature (LST) data were used to examine the spatial and temporal (diurnal, intra-annual, and inter-annual) variations in LSWT of China's lakes during 2001-2016. Our results indicated that 169 large lakes included in the study exhibited an overall increasing trend in LSWT, with an average rate of 0.26 °C/decade. The increasing rate of nighttime LSWT is 0.31 °C/decade, faster than that of daytime temperature (0.21 °C/decade). Overall, 121 (71.6%) lakes showed an increase in daytime temperature with a mean rate of 0.38 °C/decade, while the rest 48 (28.4%) lakes decreased in temperature with a mean rate of - 0.21 °C/decade. We also quantitatively analyzed the relationship of the lake surface temperature and diurnal temperature differences (DTDs) with geographical location, topography, and lake morphometry by utilizing multivariate regression analysis. Our analysis suggested that the geographical location (latitude and longitude) and topography (altitude) were primary driving factors in explaining the national lake water temperature variation (P < 0.001), which were also mediated by morphometric factors such as lake surface area and volume. Moreover, the diurnal lake temperature variations were significantly correlated with altitude, latitude, and lake surface area (R2 = 0.426, P < 0.001). Correlation analyses of LSWT trend and air temperature trend for each lake indicated that LSWT was positively correlated with air temperature in both daytime and nighttime for most lakes.

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The present study aimed to evaluate the accuracy and repeatability of morphological contour interpolation (MCI)-based semiautomatic segmentation method for volumetric measurements of bone grafts around dental implants. Three in vitro (one with a cylinder and two with a geometrically complex form) and four ex vivo models (peri-implant cylinder-shaped bone defect) were created for imitating implant placement with simultaneous guided bone regeneration (GBR) procedure. Cone beam computerized tomography (CBCT) scans of all models were obtained with the same parameters. For volumetric measurements, the actual volumes of bone grafts in models were assessed by computer-aided calculation and both manual and MCI-based methods were utilized as test methods. The accuracy of the methods was evaluated by comparing the measured value and the actual volume. The repeatability was assessed by calculating the coefficients of variation of repeated measurements. For the accuracy of three dimensional (3D) reconstructions, the computer-designed corresponding models were set as the reference and the morphological deviation of 3D surface renderings created by two methods were evaluated by comparing with reference. Besides, measurement time was recorded and a comparison between the two methods was performed. High accuracy of the MCI-based segmentation method was found with a discrepancy between the measured value and actual value never exceeding - 7.5%. The excellent repeatability was shown with coefficients of variation never exceeding 1.2%. The MCI-based method showed less measurement time than the manual method and its 3D surface rendering showed a lower deviation from the reference.

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Sargassum horneri is a habitat-forming species in the Northwest Pacific and an important contributor to seaweed rafts. In this study, 131 benthic samples and 156 floating samples were collected in the Yellow Sea and East China Sea (ECS) to test the effects of seaweed rafts on population structure and connectivity. Our results revealed high levels of genetic diversity in both benthic and floating samples based on concatenated mitochondrial markers (rpl5-rps3, rnl-atp9, and cob-cox2). Phylogenetic analyses consistently supported the existence of two lineages (lineages I and II), with divergence dating to c. 0.692 Mya (95% HPD: 0.255-1.841 Mya), indicating that long-term isolation may have occurred during the mid-Pleistocene (0.126-0.781 Mya). Extended Bayesian skyline plots demonstrated a constant population size over time in lineage I and slight demographic expansion in lineage II. Both lineages were found in each marginal sea (including both benthic and floating samples), but PCoA, FST , and AMOVA analyses consistently revealed deep genetic variation between regions. Highly structured phylogeographic pattern supports limited genetic connectivity between regions. IMA analyses demonstrated that asymmetric gene flow between benthic populations in the North Yellow Sea (NYS) and ECS was extremely low (ECS→NYS, 2Nm = 0.6), implying that high dispersal capacity cannot be assumed to lead to widespread population connectivity, even without dispersal barriers. In addition, there were only a few shared haplotypes between benthic and floating samples, suggesting the existence of hidden donors for the floating masses in the Chinese marginal seas.

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The descending duodenum is rarely involved in Schistosoma japonicum (S. japonicum) infection. Here, we report a case of acute Schistosoma infection, which presented with abdominal pain, abdominal distension and irregular fever. Tumor-like lesions were observed in the descending duodenum. Simultaneously, heterogeneity in hepatic perfusion was demonstrated by dynamic computed tomography scanning. Biopsy of the descending duodenum showed the deposition of Schistosoma eggs. Following administration of the antihelminthic drug praziquantel, the patient showed rapid clinical improvement. In conclusion, we report a patient with acute S. japonicum infection presenting as tumor-like lesions in the descending duodenum and heterogeneity of blood perfusion in liver parenchyma.

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The aim of the present study was to identify the peri-implant conditions (bleeding on probing (BOP), pocket probing depth (PPD), modified plaque index (mPI)) and marginal bone loss (MBL, marginal bone level change between follow-up and occlusal loading) around cemented and screw-retained posterior single crowns on tissue-level implants. The study was a retrospective cohort study with up to 4 years (mean 2.5 years) follow-up. Patients with either cemented or screw-retained crowns in posterior regions were included. Implant survival, technical complications, BOP, PPD, mPI, MBL, biologic complications (peri-implant mocositis and peri-implantitis) were evaluated. Mann-Whitney U test was used to test the difference between the screw-retained group (SG) and cemented group (CG). 176 patients (SG: 94, CG: 82) were included. The implant survival rates were 100% in SG and 98.8% in CG. Prosthetic screw loosening was found in 8 restorations (8.7%) at follow-up visit. Peri-implant mucositis rate was significantly higher in the SG group (42.1%) than that in the CG group (32.2%) (P = 0.04). Six patients (6.38%) in the screw-retained group and 5 patients (6.10%) in the cemented group were diagnosed with peri-implantitis, the difference did not reach statistical significance (P>0.05). No significant difference of PPD, mPI and MBL were found between two groups (P = 0.11, 0.13 and 0.08, respectively). High implant survival rates were achieved in both groups. Cemented single crowns on tissue-level implants showed comparable peri-implant conditions in comparison with two-piece screw-retained crowns. Well-designed prospective cohort or randomized controlled clinical trials with longer follow-up are needed to confirm the result.

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OBJECTIVE: The aim of this study was to evaluate the long-term survival, complications, peri-implant conditions, marginal bone loss, and patient satisfaction of fixed dental prostheses supported by narrow diameter implants (NDIs) in the posterior jaws. MATERIALS AND METHODS: This study was designed as a retrospective cohort study with a mean follow-up time of 10.1 years (SD: 2.5 years). Patients receiving NDIs in posterior jaw were reviewed. Implant survival, hardware complication, modified plaque index (mPI), peri-implant probing depth (PPD), percentage of bleeding on probing (BOP%), marginal bone loss (MBL), and patient satisfaction were evaluated. Log-rank test and t test were used to detect the influence of implant location and restoration type. RESULTS: Sixty-seven patients with 98 NDIs (Premolar site: 81, Molar site: 17, Single crowns: 33, Splinted restorations: 65) were included. The overall implant survival rates were 96.9% at implant level and 97.0% at patient level. Veneer chipping was the most common hardware complication. The veneer chipping rates were 19.4% at patient level and 18.4% at implant level. All patients showed acceptable oral hygiene. Thus, the average MBL was 1.19 mm at implant level and 1.15 mm at patient level. Eight implants (8.5%) and six patients (9.2%) were diagnosed with peri-implantitis. Fifty-eight patients (89.2%) were satisfied with the esthetics of the restorations, while 55 patients (84.6%) were satisfied with the function of the restorations. CONCLUSION: Narrow diameter implants could be a predictable treatment option in the long term. High survival rates, high patient satisfaction, acceptable complication rates and marginal bone loss could be achieved. Further long-term studies are needed to evaluate the predictability of NDIs in molar sites.

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PURPOSE: The aim of this review was to systematically appraise survival rates of implants placed using the osteotome technique with and without grafting in the published literature. MATERIALS AND METHODS: An electronic search was conducted to identify prospective and retrospective studies on osteotome sinus floor elevation published between January 1, 2000 and October 30, 2015. Studies were included that (1) involved use of the osteotome technique with or without grafting; (2) provided data regarding the implant survival rates, residual bone height (RBH), and grafting materials; and (3) reported mean follow-up of at least 1 year after functional loading and included a minimum of 10 patients. The mean weighted cumulative implant survival rates were used to compare the two treatment strategies-grafted or nongrafted. The influence of RBH and implant length on weighted cumulative implant survival was also evaluated. RESULTS: After search and evaluation of the literature according to the inclusion criteria, 34 studies involving 1,977 patients and 3,119 implants were included. Eighty-four out of 102 implant failures documented in the studies occurred within 1 year of functional loading. Statistically significant differences in the cumulative survival rates were found in the graft and nongraft groups (95.89% and 97.30%, respectively; P = .05). In the nongraft group, no statistically significant difference in the cumulative survival rate was found when implants were placed at RBH < 5 mm or ≥ 5 mm (95.04% and 97.63%, respectively; P = .12). In the graft group, however, a statistically significant difference was found when implants were placed at RBH < 5 mm or ≥ 5 mm (92.19% and 97.59%, respectively; P < .01). Significantly lower weighted mean cumulative implant survival rates were found in the shorter (< 8 mm) implant group than in the longer (≥ 8 mm) implant group (83.33% and 96.28%, respectively; P < .01). CONCLUSION: The cumulative survival rates were significantly higher in the nongraft group than in the graft group. Early failures (< 1 year functional loading) accounted for the vast majority of the implant failures. The cumulative survival rates in the graft group were significantly lower when the RBH was < 5 mm, while the cumulative survival rates in the nongraft group demonstrated no statistically significant difference based on RBH. Shorter (< 8 mm) implants demonstrated significantly lower cumulative survival rates than longer implants.

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OBJECTIVES: To test the reliability and validity of implant stability quotient (ISQ) values used for assessment of the condition of bone-to-implant interface in the osteotome sinus floor elevation (OSFE) model and to evaluate the influence of residual bone height (RBH) on ISQ values. MATERIAL AND METHODS: Forty-six Straumann(®) tissue-level SLA implants (Φ4.8 mm*8 mm, wide neck, standard plus) placed in 39 patients applying OSFE without grafting were included in the study. Patients were assigned to three groups based on the RBH with one implant per patient randomly chosen: (1) 2 ≤ RBH < 4 mm (n = 14); (2) 4 ≤ RBH < 6 mm (n = 15); (3) 6 ≤ RBH < 8 mm (n = 10). ISQ values were determined with Osstell ISQ(®) at 0, 2, 4, 8, 12, 16, and 20 weeks postoperation. The reliability of RFA measurements was tested by the degree of dispersion of ISQ values at each time point, and the validity was tested by linear correlation between ISQ and RBH. ISQ values were then compared among groups at all observed time points. RESULTS: The implants achieved a mean ISQ value of 63.6 immediately after surgery and reached a higher ISQ level of 70 after 20 weeks with a dip at 4 weeks. A higher degree of dispersion of ISQ values was observed immediately after surgery compared to the other time points. No significant correlations were found between RBH and ISQ values and no significant difference in ISQ values among groups at all the time points. CONCLUSION: Within the limits of the study, it may be implied that ISQ values are not able to assess the condition of bone-to-implant interface and the role of single RFA measurement in determining loading protocol is questionable.

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OBJECTIVE: To compare the prevalence and levels of six bacterial pathogens within the subgingival/submucosal microbiota at teeth versus implants with various clinical conditions. MATERIAL AND METHODS: Twenty-two Chinese were included. Four subgingival/submucosal sites were selected for microbiological sampling within each subject, that is, (1) healthy peri-implant tissues; (2) peri-implantitis [PPD ≥ 5 mm, presence of bleeding on probing (BOP) and confirmed radiographic bone loss]; (3) healthy gingiva; and (4) periodontitis (PPD ≥4 mm). Subgingival/submucosal plaque was sampled using paper points. Quantitative real-time polymerase chain reaction (q-PCR) was used to quantify six pathogens, including Porphyromonas gingivalis (P.g.), Treponema denticola (T.d.), Aggregatibacter actinomycetemcomitans (A.a.), Fusobacterium nucleatum (F.n.), Prevotella intermedia (P.i.), and Staphylococcus aureus (S.a.). Counts were log10-transformed. RESULTS: The most commonly detected species were S. a. and F. n., while A. a. and. P. i. had the lowest detection frequency. The detection frequencies of diseased tooth or implant sites for each of the six target species were either equal to or higher than the respective frequencies at the corresponding healthy sites. There were no statistically significant differences for any of the species or clinical sites (P > 0.05, Cochran's Q test). No statistically significant differences in the bacterial loads were found among the four clinical sites; with the exception of F. nucleatum. This was more abundant in periodontitis sites (P = 0.023, Friedman's 2-way anova). Both periodontal and peri-implant sites, irrespective of their health status, were revealed to harbor S. aureus cells. The log10-transformed loads of S. aureus were approximately 3.5 within each of the clinical sites (P = 0.232). This was the highest of the six species analyzed. CONCLUSIONS: Within the same subjects, putative periodontal pathogens were common to both periodontal and peri-implant sites irrespective of health status. The prevalence and levels of P. gingivalis and F. nucleatum were significantly associated with periodontitis, but not with peri-implantitis. A. actinomycetemcomitans was associated with both disease conditions, periodontitis and peri-implantitis, but not with either gingival or mucosal health.

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Bacterial taxa belonging to the phylum Synergistetes are commonly detected within diseased periodontal niches, but are rarely found within healthy oral sites. However, as they typically constitute a minor fraction of the oral microbiota, their precise distributions and disease-associations remain to be fully established. Here, we surveyed the Synergistetes taxa present within individual periodontal/subgingival and peri-implant/submucosal sites, within Chinese subjects (n = 18) affected by both peri-implantitis and periodontitis. Four individual, clinically-distinct sites were analyzed in each patient: healthy sulcus; periodontitis lesion; healthy peri-implant space; peri-implantitis lesion. We employed a clone library-based approach, using PCR-primers that specifically amplified ca. 650bp regions of the 16S rRNA gene from oral cluster A and B Synergistetes taxa. Twenty-one of the 72 sites (from 12/18 subjects) yielded Synergistetes 16S rRNA PCR products. Sequencing of cloned amplicon libraries yielded 1338 quality-filtered 16S rRNA sequences, which were assigned to 26 Synergistetes operational taxonomic units (OTUs; oral taxon SH01-SH26) using a 98.5% identity cut-off. We identified 25 Synergistetes oral cluster A OTUs (genus Fretibacterium; corresponding to Human Oral Taxon (HOT) numbers 358, 359, 360, 361, 362, 363, 452, and 453), and one oral cluster B OTU (Pyramidobacter piscolens oral taxon SH04, HOT-357). Three OTUs predominated: Fretibacterium oral taxon SH01 (HOT-360), Fretibacterium oral taxon SH02 (HOT-452), and Fretibacterium fastidiosum oral taxon SH03 (HOT-363). The Synergistetes community compositions within the respective periodontal and peri-implant sites were variable and complex, and no statistically-significant correlations could be established. However, the detection frequency of F. fastidiosum SH03 and Fretibacterium oral taxon SH01 were both positively associated with plaque index at healthy subgingival sites. Taken together, our results show that diverse Synergistetes populations inhabit both diseased and healthy periodontal and peri-implant niches, with considerable site-to-site variations in composition occurring within the same oral cavity.

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OBJECTIVE: The aim of this study was to assess the clinical success of dental implants placed in severely atrophic maxilla (residual bone height ≤4 mm) using transalveolar sinus floor elevation (TSFE) without grafting. Furthermore, the implant stability during the healing period was also evaluated. MATERIALS AND METHODS: Twenty five generally healthy patients with 37 Straumann(®) Standard Plus SLA implants were included in the study. After a modified Summers TSFE without grafting was performed, the smooth collar was embedded 0.5-1 mm beneath the cortical bone level. Follow-ups were conducted at 12, 36, and 60 months after crown placement. Implant survival rate, resonance frequency analysis (RFA), and clinical and radiographic parameters were evaluated. RESULTS: At 5-year follow-up, 35 implants fulfilled the survival criteria, representing a 5-year cumulative survival rate of 94.6% at implant level and 92% at subject level. The mean value of implant stability quotient (ISQ) ranged from 67.8 to 72.8, and the lowest values were reached at 4 weeks. No significant difference was found with the passage of time in modified plaque index (P = 0.92), pocket probing depth (P = 0.34), and modified bleeding index (P = 0.4). The average residual bone height was 2.81 mm (SD: 0.74 mm) in this study. The average crestal bone loss (CBL) significantly increased from 0.83 mm at 1-year examination to 1.47 mm at 3-year examination (P < 0.001). The average CBL remained stable at years 3 and 5 (1.47 vs. 1.54 mm, P = 0.083). CONCLUSION: According to the current evidence, it is feasible to place cylindrical implants in severely atrophic maxilla. High survival rate could be achieved following TSFE without grafting at least within 5-year follow-up.

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BACKGROUND: Nowadays, short dental implants are being increasingly applied in extremely resorbed posterior regions. The recent studies have indicated that short implants present a similar success rate to conventional implants. It is assumed that short implants can avoid additional surgical morbidity and are less technically demanding. However, high-quality evidence (≥ Ib: evidence from at least one randomized controlled trial) on comparing the clinical outcome of short implants and longer implants combined with osteotome sinus floor elevation (OSFE) technique is limited. METHODS/DESIGN: The proposed study is designed as a prospective single-center, three-arm parallel group, randomized controlled trial. We plan to enroll 150 patients in need of dental implant treatment in the posterior maxilla. The inclusion criteria include: age ≧ 18 years, partial edentulism in the posterior maxilla for at least 3 months from tooth loss, residual bone height ranging from 6 to 8 mm, sufficient bone width (≥ 6 mm) in the edentulous region. The patients will be divided into three groups according to a table of random numbers: group 1: short implants (6 mm) alone; group 2: short implants (8 mm) combined with osteotome sinus floor elevation (OSFE); group 3: standard implants (10 mm) combined with OSFE. The assignment will be concealed from the clinical operators until the beginning of implant surgery. The outcome examiners and patients will be kept blinded to the assignment. Implant survival rates, implant success rates, complications, resonance frequency analysis (RFA) measurements, marginal bone level, treatment time and patient-reported outcome (visual analogue scale for intraoperative discomfort and postoperative pain) will be recorded. Clinical re-evaluations will be performed at 12, 24, 36 and 60 months after crown placement. DISCUSSION: The results of the trial will support better decision-making for dental implant treatment in atrophic maxillary ridges. If favorable, the use of short implants may avoid adjunct procedures used for implant insertion, thus reducing operative time, complexity and postoperative discomfort. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT02350075 (registered on 17 February 2015).

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AIM: To evaluate implant stability and histological outcomes after osteotome sinus floor elevation (OSFE) procedure, and to compare new bone formation and implant osseointegration with and without grafting. MATERIAL AND METHODS: OSFE with simultaneous implant placement was conducted bilaterally on 6 Labrador dogs. Twenty-four implants were placed. The right side sinus (Group 1) was grafted with biphasic calcium phosphate (BCP), whereas the left side (Group 2) was left without any grafting materials. The animals were euthanized 8 and 24 weeks after surgery for histological and histomorphometric assessment. Bone-to-implant contact (BIC%), alveolar bone height (ABH), bone density (BD) and grafting material density (GMD) were measured. The implant stability (ISQ) was assessed using resonance frequency analysis (RFA) at implant placement and 1, 2, 4, 8, 12, 24 weeks after surgery. RESULTS: Endo-sinus new bone with direct contact to implant surface were observed in two groups at both time points. ABH showed no difference between groups at both time points. BIC% and BD in Group 2 (40.05%, 35.90%) was higher than those in Group 1 (23.30%,25.59%) at 24 weeks. Significant shrinkage of grafting material was seen in Group 1. The GMD in Group 1 at 8 weeks was 24.35%, while it dropped to 19.90% at 24 weeks. The changing pattern of ISQ for both groups were similar. CONCLUSIONS: Spontaneous new bone formation and better bone-to-implant contact were found for OSFE without grafting. The grafting material application during OSFE procedure showed no advantages in histological results.

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OBJECTIVE: The aim of the current review was to systematically appraise the esthetic outcome of soft tissue around single implant crowns following type 1 and type 3 implants placement in published dental literature. MATERIALS AND METHODS: A PubMed, Embase, and the Cochrane Central Register of Controlled Trials search up to March 2013 was conducted for articles published in the dental literature and limited to human trials with no language restricted. Furthermore, the reference lists of related articles were systematically screened, and additional manual searches were also performed. The primary outcome was pink esthetics score (PES). RESULTS: The electronic search in the database of PubMed, Embase, and the Cohrane Central Register of Controlled Trials resulted in the identification of 463 titles. These titles were initially screened by the two independent reviewers for possible inclusion. Screening the abstracts and titles led to 28 articles for future full-text consideration. From these articles, 18 studies were excluded. Manual search identified one article. After quality assessment, eight studies were included in this review. This review showed that no significant difference of PES index could be found between type 1 and type 3 implant placement. CONCLUSION: According to the current evidence, short-term esthetic outcomes of peri-implant soft tissue did not show significant difference following type 1 and type 3 implants placement with well-selected patients. However, caution should be taken for clinicians to extrapolate this result to all types of patients, as more randomized clinical trials are needed for long-term soft-tissue esthetic outcome in patients with high esthetic risk following type 1 implant placement. PES frequency, peri-implant condition and other risk factors for peri-implantitis are recommended to be reported for future studies.

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OBJECTIVE: The aim of this prospective study was to assess the esthetic outcome and alterations of peri-implant soft tissue using tissue-level implants. Furthermore, the influencing factors, including grafting and gingival biotype, of esthetic outcome of peri-implant soft tissue were also evaluated. MATERIALS AND METHODS: Of 38 patients with single missing anterior tooth in maxilla were treated with a Straumann (®) Standard Plus SLA implant. Bone augmentation was performed in 24 patients. Follow-up was conducted at 12 and 24 months after definitive crowns placement. Esthetic outcome using the pink esthetic score/white esthetic score (PES/WES) and clinical parameters were evaluated. RESULTS: The mean PES/WES value at baseline, 1-year, and 2-year examination was 13.79, 14.87, and 14.96. Significant improvement was found between baseline and 1-year examination (P < 0.01). And the improvement between 1-year and 2-year examination was not significant (P = 0.40). The mean PES changing value in patients with thick biotype was significantly higher than those with thin biotype at 2-year after definitive crowns placement (P = 0.03). Graft procedure had an unfavorable effect on mean PES value both at baseline and at follow-up (P < 0.01). No implants were lost at 2-year examination. Three patients experienced peri-implant infection. No significant difference was found with the passage of time in modified plaque index (mPI), probing pocket depth (PPD), and modified bleeding index (mBI). CONCLUSION: According to the present prospective clinical study, it can be concluded that it is feasible to use tissue-level implant to support single crowns in esthetic area. Favorable short-term esthetic outcome and stability of soft tissue around single implant crowns can be expected in patients with or without graft. However, graft procedures might have an unfavorable effect on the esthetic outcome. Gingival biotype can be considered as prognostic factor for esthetic outcome. RCTs with long-term follow-up are needed to provide evidence for the long-term stability of peri-implant soft tissue using tissue-level implant systems.

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AIM: To characterize the subgingival microbiota within a cohort of adult males (n = 32) naïve to oral hygiene practices, and to compare the composition of bacterial taxa present in periodontal sites with various probing depths. MATERIAL AND METHODS: Subgingival plaque samples were collected from single shallow pocket [pocket probing depth (PPD)≤3 mm] and deep pocket (PPD≥6 mm) sites from each subject. A polymerase chain reaction based strategy was used to construct a clone library of 16S ribosomal RNA (rRNA) genes for each site. The sequences of ca. 30-60 plasmid clones were determined for each site to identify resident taxa. Microbial composition was compared using a variety of statistical and bioinformatics approaches. RESULTS: A total of 1887 cloned 16S rRNA gene sequences were analysed, which were assigned to 318 operational taxonomic units (98% identity cut-off). The subgingival microbiota was dominated by Firmicutes (69.8%), Proteobacteria (16.3%), and Fusobacteria (8.0%). The overall composition of microbial communities in shallow sites was significantly different from those within deep sites (∫-Libshuff, p < 0.001). CONCLUSIONS: A taxonomically diverse subgingival microbiota was present within this cohort; however, the structures of the microbial communities present in the respective subjects exhibited limited variation. Deep and shallow sites contained notably different microbial compositions, but this was not correlated with the rate of periodontal progression.

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AIMS: To evaluate the clinical and radiographic results of dental implant placed using osteotome sinus floor elevation (OSFE) with and without simultaneous grafting. MATERIALS & METHODS: Forty-five patients were randomly assigned into two groups: Group1: OSFE with deproteinized bovine bone mineral (DBBM) mixed with autogenous bone chips, and Group2: OSFE without grafting. The endo-sinus bone gain (ESBG) was assessed on radiographs at 6, 12, 24, 36 months following surgery as primary outcome measurement. Implant survivals and marginal bone loss (MBL) were assessed as secondary outcome measurements. RESULTS: Twenty-one implants in Group1 and 20 implants in Group2 were analysed. The residual bone height (RBH) was 4.63 ± 1.31 mm in average (4.67 ± 1.18 mm for Group1 and 4.58 ± 1.47 mm for Group2). The 3-year cumulative survival rates of implants were 95.2% for Group1 and 95.0% for Group2. The ESBG in Group1 reduced from 5.66 ± 0.99 mm at 6 months to 3.17 ± 1.95 mm at 36 months, whereas the ESBG in Group2 increased from 2.06 ± 1.01 mm at 6 months to 3.07 ± 1.68 mm at 36 months. The MBL after 3 years was 1.33 ± 0.46 mm in Group1 and 1.38 ± 0.23 mm in Group2. CONCLUSIONS: OSFE and simultaneous implant installation with and without grafting both resulted in predictable results. The application of grafting materials has no significant advantage in terms of clinical success.

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OBJECTIVE: Aimed to evaluate the long-term clinical and radiographic outcomes of short implants supporting single crowns in the posterior regions. MATERIAL AND METHODS: A retrospective study design was adopted. The clinical and radiographic data of 231 short implants (intra-bony length ≤8 mm) supporting single crowns in 168 patients, were collected after 5-10 (mean 7.22) years' follow-up. Implant and prosthesis failures, peri-implant marginal bone loss, biological and technical complications were evaluated. The influence factors on implant failure were studied. RESULTS: In total 4 implants and 11 prostheses failed. The 10-year (5-year) cumulative survival rate was 98.3% (98.7%) for implant-based analysis and 97.6% (98.2%) for patient-based analysis. The short implants placed in type IV bone yielded more failures than in type I-III and presented a survival rate of 94.0%. The 10-year survival rate of the prostheses was 95.2%. The mean marginal bone loss between implant installation and the 10 years' follow-up visit was 0.63 ± 0.68 mm. The marginal bone loss between the first and 5th year was minimal (0.05 ± 0.10mm and not statistically significant). 18 (7.8%) implants were exposed to biological complications, whereas 29 (12.6%) implants were involved in technical complications. CONCLUSIONS: High survival rates for both the implants and the prostheses could be achieved after 5-10 years for short implants supporting single crowns, without severe marginal bone loss and complications. One may conclude that a single crown supported by a short implant is a predictable treatment modality. However, short implants in type IV bone sites should be applied with caution.

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