Emergence Angle Research Articles

Effect of Emergence Angle on Acoustic Transmission in a Shallow Sea

In this study, the effect of the emergence angle of a source array on acoustic transmission in a typical shallow sea is simulated and analyzed. The formula we derived for the received signal based on the Normal Mode indicates that the signal is determined by the beamform on the modes of all sources and the samplings of all modes at the receiving depth. Two characteristics of the optimal emergence angle (OEA) are obtained and explained utilizing the aforementioned derived formula. The observed distributions of transmission loss (TL) for different sources and receivers are consistent with the obtained characteristics. The results of this study are valuable for the development and design of active sonar detection.

Association of crown emergence angle and profile with dental plaque and inflammation at dental implants.

The shape of implant restorations is critical for function and aesthetics. It may also be important in peri-implant tissue health preservation. This study aimed to associate the restorative contour of a single crown with marginal dental plaque accumulation, tissue inflammation and probing depths. Subjects with a single screw-retained implant restoration were clinically examined. The presence of dental biofilm, tissue inflammation and probing pocket depths were the dependent variables. The emergence angle, profile and depth of the mucosal tunnel were measured on superimposed digital scans of the crown soft-tissue complex, the removed crown mounted on an analogue and the soft tissue. One hundred twenty two subjects (46.7% female, 68.9% never smokers, 77% with treated periodontitis and 52.5% participating in regular supportive peri-implant care) were examined. The emergence angles at the mucosal margin were 15.3 ± 9.4°, 12.7 ± 8.5°, 31.3 ± 11.8° and 19.2 ± 9.8° for the mesial, distal, vestibular and oral aspects of the crowns. The largest emergence profile angles were observed on the vestibular aspect (74.6% of cases), reaching a maximum of 61.7°, and profiles were convex in 59% of cases. Generalized estimating equations indicated that the site-specific platform-level emergence angle and profile and depth of the mucosal tunnel were significantly associated with the presence of detectable plaque accumulation (p < .01) and bleeding on probing (p < .02). Subtle variations in the shape of the restorative crown are associated with biofilm accumulation and mucosal inflammation. These findings are important for 3D implant planning/positioning and preservation of peri-implant tissue health.

The 3D emergence profile on implant-supported restorations: A method for evaluating restorative angles.

Emerging evidence indicates that the emergence profile and subsequent restorative angle play a crucial role in clinical outcomes and can potentially affect the development and progression of peri-implant diseases. However, the traditional evaluation of the emergence profile and angle has been limited to mesial and distal sites using periapical x-rays, without considering the buccal sites. To describe a novel 3D method to estimate the emergence profile and restorative angles around single implant-supported crowns including buccal sites. A total of 30 implant-supported crowns (11 molars, 8 premolars, 8 central incisors and 1 canine) were extra-orally scanned using an intraoral scanner and the STL files produced were imported into a 3D software. The crown/abutment interface of each crown was delineated, and apico-coronal lines were automatically drawn following the shape of the crown. Three reference points were defined on the apico-coronal lines at the transition edge of the biological (BC) and the esthetic zone (EC) and the resulting angles were then calculated. The reliability of the measurements (2D and 3D) were assessed using the intraclass correlation coefficient (ICC). In anterior restorations, the mean angle of the esthetic zone amounted to 162 ± 14° at mesial sites, to 140 ± 10° at buccal sites and to 163 ± 11° at distal sites. The corresponding angles at the biological zones, amounted to 155 ± 13° at mesial sites, 139 ± 15° at buccal sites and 157 ± 5° at distal sites. In posterior restorations, the mean angle of the esthetic zone amounted to 162 ± 12° at mesial sites, to 157 ± 13 at buccal sites and to 162 ± 11 at distal sites. The corresponding angles at the biological zone, amounted to 158 ± 8 at mesial sites, 150 ± 15° at buccal sites and 156 ± 10 at distal sites. The ICC for all measurements ranged between 0.77 and 0.99 indicating a good intra-examiner reliability. Within the limitations of the present study, the 3D analysis seems to be a reliable and applicable method for the quantitative evaluation of the emergence profile in daily practice. Future randomized clinical trials are needed to assess whether a 3D analysis with the ensuing the emergence profile serves as a predictor for clinical outcomes. The development and implementation of a 3D workflow will provide technicians and dentists with the ability to assess the restorative angle of implant-supported restorations during the provisional phase and the final restoration. This approach may help achieve an aesthetically pleasing restoration while minimizing potential clinical complications.

Directional light output enhancement of scintillators by mixed-scale microstructures based on soft-X-ray interference lithography and self-assembly

In this paper, we have successfully demonstrated that the directional control of the light output of the scintillator can be achieved by mixed-scale microstructures which integrate photonic crystals on the wavelength scale and microlens arrays on the micrometer scale. Compared to the reference sample, the mixed-scale microstructures can enhance the light output of the scintillator by 3.07-fold at the emergence angle of 35°. This enhancement in the light output exhibits both azimuthal angle and wavelength dependence. Our hybrid simulation and experimental characterization explain the physical mechanism behind the enhanced directional light output. This method holds potential for application in radiation detection systems and other light-emitting devices requiring directional light output.

Splinting or Nonsplinting Adjacent Implants? A Retrospective Study Up to 15 Years: Part II-Success and Survival Rate Analysis.

To analyze the success and survival of splinted and nonsplinted implants. A total of 423 patients (n = implants: 888) were included in the study. The success and survival of implants for 15 years were analyzed using a multivariable Cox regression model, and the significant effect of the splinting of prostheses and other risk factors were evaluated. The cumulative success rate was 34.2%: 33.2% in nonsplinted (NS) and 34.8% in splinted implants (SP). The cumulative survival rate was 92.9% (94.1%, NS; 92.3%, SP). Whether to splint was not related to the success and survival of implants. The smaller the implant diameter, the lower the survival rate. The crown length and implant length were significantly associated only with NS implants: The longer the crown length and the shorter the implant length, the greater the risk of implant failure. The emergence angle (EA) and the emergence profile (EP) had a significant effect on only the SP implants: EA3 showed a higher risk than EA1, and EP2 and EP3 had a higher risk of implant failure. Crown length and implant length affected only the nonsplinted implants: The higher the crown length and the shorter the implant length, the greater the risk of implant failure. A significant effect for emergence contour was found only in SP implants: the implants restored with prostheses with EA ≥ 30 degrees on both the mesial and distal sides, and convex EP on at least one side had higher risks of failure. Int J Oral Maxillofac Implants 2023;38:443-450. doi: 10.11607/jomi.10054.

Reflectance spectra of mascagnite and salammoniac minerals with varying viewing geometry

We analyse the quantitative effects of viewing geometry variations on the near-infrared reflectance spectra of mascagnite-(NH4)2SO4 and salammoniac-NH4Cl samples. Bi-directional reflectance spectra are collected in the 1–4.2 μm range considering a set of 3 incidence (i) angles (i = 0°; 30°; 60°) and 9 emergence (e) angles between −70° and 70° at room temperature and computed with respect to the normal direction. The NH4+ overtone and combinations bands located at ∼1.09, 1.32, 1.62, 2.04, 2.2 and 3.05 μm are experimentally investigated. The bidirectional reflectance spectra of these samples show significant variations with the observation geometry in terms of reflectance values, spectral slope, and absorption bands parameters. The band positions remain essentially unchanged by varying the incident and emergence angles. On the other hand, bands' area and depth show the highest variability for i ≥ 30° and e greater than ±40°(up to a factor 2.3 in relative mean variation). The area and depth parameters of these bands show a dual behaviour: (i) for the weak-medium spectral features below 2 μm the area and depth decrease as the phase angle increases. (ii) The strong spectral features above 2 μm increase their values only at phase angles above 90°, but also at low phase angles for high incidences, i ≥ 30°. This behaviour is linked both to the non-linear radiative transfer in particulate media and to the way the band depth and area are defined, relative to the local continuum. We observe important dependence (up to ∼60% relative mean variation) of band depth and area on the incidence angle, up to 60°, compared to moderate variation with emergence angles (up to ∼20% relative mean variation). Furthermore, the ∼3 μm features becomes more saturated at ±70° emergence angles. A general trend of spectral bluing with change in observation geometry is observed. The current dataset is a contribution in the framework of present and future space missions focused on understanding the nature and quantification of ammonium-bearing minerals on icy bodies. The NH4+ − bearing minerals identification could provide information on: (i) ocean/brine compositions, (ii) possible explanations of geological phenomena and (iii) implications for biological activity.

Association of prosthetic angles of the Implant Supracrestal Complex with peri-implant tissue mucositis.

The aim of this study was to investigate the association of the Mucosal Emergence Angle (MEA) with peri-implant tissue mucositis. Forty-seven patients with 103 posterior bone level implants underwent clinical and radiographic examination. Three-dimensional data from Cone Bean Computer Tomography and Optica Scan were transposed. Three angles were defined: MEA, Deep Angle (DA) and Total Angle (TA) and measured at six sites for each implant. There was a significant correlation between MEA and Bleeding on Probingfor all sites with an overall odds ratio of odd ratio1.07 (95% confidence interval [CI] 1.05-1.09, p < 0.001). Sites with MEA ≥ 30°, 40°, 50°, 60°, and 70° had a higher risk for bleeding with an odds ratio of 3.1, 5, 7.5, 11.4 and 33.55, respectively. When all 6 sites of an implant prostheses had MEA ≥ 40°, the risk of having bleeding at all 6 sites was 9.5 times higher (95%CI 1.70-52.97, p = 0.010). Maintaining MEA no wider than 30°-40° is advisable, while the aim should be to keep this angle as narrow as clinically feasible.Registered in Thai Clinical Trials Registry: http://www.thaiclinicaltrials.org/show/TCTR20220204002.

Influence of implant restorative emergence angle and contour on peri-implant marginal bone loss: A systematic review and meta-analysis.

Implant restorative emergence angle and profile may have a negative impact on peri-implant marginal bone level and may increase the risk of developing peri-implantitis. However, the role of these prosthetic features on peri-implant health is still unclear. The aim of this systematic review and meta-analyses was to evaluate the long-term outcomes of implant restorations with an emergence angle of >30° in comparison to those with ≤30° in terms of changes in peri-implant marginal bone level, periodontal parameters, and prevalence rate of peri-implantitis. Electronic databases were searched to identify observational studies that compared implant restorations with an emergence angle of >30° to those with ≤30°. The risk of bias was assessed using the Cochrane Collaboration's Risk of Bias tool. Four studies with 912 dental implants in 397 participants were included in the present review. Of these, 455 implants had restorations with an emergence angle of >30°, while the remaining implants had restorative emergence angle of ≤30°. The follow-up time varied between 3.8 and 10.9 years. Implant restorations with an emergence angle of ≤30° were associated with less changes in peri-implant marginal bone level compared to those with emergence angle of >30°. The difference, however, was not statistically significant (mean difference 0.80; 95% confidence interval (CI) -0.13 to 1.72; p = 0.09). In platform-matched implants, the difference between the two groups was statistically significant in favor of implant restorations with emergence angle of ≤30°. In terms of emergence profile, implant restorations with convex profile had significantly higher rate of peri-implantitis (57.8%) compared to implant restorations with concave or straight profile (21.3%) (risk ratio 2.32; 95% CI 1.12-4.82; p = 0.02). Within the limitation of this review, implant restorations with an emergence angles of >30° or ≤30° seem to have no significant influence on peri-implant marginal bone level. Platform-matched implants with an emergence angle of ≤30° may have positive effects on the peri-implant marginal bone level changes, but the evidence support is of low to moderate certainty.

Infrared All-Dielectric Metasurface Beam Splitter Based on Transflective Structures

Beam splitters are widely applied in various optical systems as a common beam-splitting device. The conventional stereoscopic and flat-type beam splitters greatly limit the packaging and integration of optical systems due to their large size and restricted emitting direction. Recently, beam-splitting devices made of various transmissive or reflective metasurfaces have shown the potential to overcome these challenges. However, in optical systems such as machine vision, these single-ended beam splitters increase the design complexity of the signal feedback link due to the limitation of the beam-splitting path direction. Here, we proposed and numerically simulated a transflective all-dielectric metasurface beam splitter by applying incompletely transmissive structural designs to the metasurface and using the transmission phase modulation mechanism. It can realize the beam separation for arbitrarily polarized incident light on the same side of the normal at both transmissive and reflective ends with a single-layer unit cell arrangement structure and has a similar emergence angle. The results reveal that at 1550 nm, the angular tolerance bandwidth is about 32°, the total splitting efficiency is over 90%, and the splitting ratio is approximately 1:1. After comparison and verification of simulation results, this transflective metasurface beam splitter is hopeful to be applied in new compact optical systems that require real-time signal feedback, such as coaxial light sources and photoelectric sensing.

The apparent focal depth, emergence angle, and take-off angle of seismic wave measured by YRY-4-type borehole strainmeter as one kind of strain seismograph

Introduction: In theory, the observation objects and principles of strain seismograph and traditional pendulum seismograph are different, and the characteristics of observed signals should also be dissimilar. The observation results of pendulum seismograph show that seismic waves in inhomogeneous media will undergo refraction, reflection, and attenuation. Then, what signal characteristics can be detected by strain seismograph is great significance for understanding and explaining the observation results.Methods: Using YRY-4 type four-gauge borehole strainmeter as one kind of strain seismograph to detect the strain tensor change of the plane seismic wave emitted from the surface, a five-site strain seismograph observation network was built in Shanxi Province, with continuous observation for 2 years at a sampling rate of 100 Hz. In this paper, two local events occurring in the area covered by the strain seismograph observation network are taken as examples. We systematically studied the characteristics of seismic wave signals recorded by strain seismographs at five sites, inverted for the focal depth of the two local earthquakes and the relationship between the wave velocity and the wave velocity gradient of the focal depth, and calculated the apparent focal depth, the emergence angle and the take-off angle of seismic waves.Results: These results show stable uniqueness and apparent regularity, especially since the inverted focal depths are basically consistent with the seismic solutions based on those traditional pendulum seismographs. The observations from this study show that the strain seismograph can be used as an effective supplement to the pendulum seismograph.Discussion: In the future, we will continue to study the rupture process and focal mechanism of moderate-strong earthquakes and teleseismic earthquakes by combining two kinds of observations.

Implant connection and abutment selection as a predisposing and/or precipitating factor for peri-implant diseases: A review.

Peri-implant mucosal integration is becoming a critical aspect for long term implant health and can be triggered the selection of implant components. The aim of this review is therefore to investigate the evidence concerning implant connection and abutment characteristics (abutment materials, design, handling) as predisposing or precipitating factor for peri-implant mucositis and peri-implantitis. Although the evidence that these features can directly predispose/precipitate peri-implant diseases is limited, there are -few- studies showing a potential role of the implant connection, trans-mucosal configuration, and handling in the development of early bone loss and/or peri-implantitis.With bone level implants, conical internal connections (with inherent platform switching) might be preferred over internal flat-flat and external connections to decrease the risk of early bone loss and potentially the risk of peri-implant disease. Moreover, there is a trend suggesting moving the prosthetic interface coronally (to the juxta-mucosal level) as soon as possible to reduce the number of disconnections and to limit the risk of cements remnants. This can be achieved by choosing a tissue-level implant or to place a trans-mucosal abutment (one abutment-one time approach) to optimize the peri-implant soft tissue seal. In absence of evidence for the biocompatibility regarding several restorative materials, biocompatible materials such as titanium or zirconia should be preferred in the trans-mucosal portion. Finally, longer implants (≥2mm) with an emergence angle below 30° seem more favourable.It should however be noted that some of this information is solely based on indirect information (such as early bone loss) and more research is needed before making firm recommendations about abutment choice.

Asymmetric ranging algorithm based on signal emergence angle for underwater wireless sensor network

Asymmetric ranging algorithm based on signal emergence angle for underwater wireless sensor network

Association between Peri-Implant Soft Tissue Health and Different Prosthetic Emergence Angles in Esthetic Areas: Digital Evaluation after 3 Years' Function.

The aim of the present retrospective study was to assess peri-implant soft tissue health for implants restored with different prosthetic emergence profile angles. Patients were treated with implants supporting fixed dentures and were followed for 3 years. Buccal emergence angle (EA) measured at 3 years of follow-up visits (t1) were calculated for two different groups: Group 1 (153 implants) for restorations with angle between implant axis and prosthetic emergence angle from ≥30°, and Group 2 (67 implants) for those with angle ≤30°, respectively. Image J software was used for the measurements. Moreover, peri-implant soft tissue parameters such as pocket probing depth (PPD), plaque index (PI) and gingival index (GI) were assessed, respectively. A total of 57 patients were included in the analysis and a total of 220 implants were examined. Mean (±SD) EA in Groups 1 and 2 was 46.4 ± 12.2 and 24.5 ± 4.7 degrees, respectively. After 3 years of follow-up, a PPD difference of 0.062 mm (CI95% -0.041 mm; 0.164 mm) was calculated between the two groups and was not statistically significant (p = 0.238). Similar results were found for PI (OR = 0.78, CI95% 0.31; 1.98, p = 0.599). Furthermore, GI scores of 2 and 3 were found for nine implants (5.9%) in Group 1, and for five implants in Group 2 (7.5%). A non-significant difference (p = 0.76) was found. Peri-implant soft-tissue health does not seem to be influenced by EA itself, when a proper emergence profile is provided for implant-supported reconstructions in anterior areas.

Screening of Coronary Artery Origin by Echocardiography: Definition of Normal (and Abnormal) Take-Off by Standard Echocardiographic Views in a Healthy Pediatric Population.

Background: Echocardiographic screening of anomalous coronary artery origin is of increasing interest for children participating in sport activities. However, criteria to define normal coronary artery origins in children are poorly defined. Thus, the aim of the present investigation is to define the normal origin and angle of emergence of coronary arteries by echocardiography in healthy children. Materials and methods: The distances of the left main and right coronary artery (LMCA, RCA) origins from the aortic annulus were measured in the parasternal long-axis view (LAX). The angle of coronary artery emergence was measured in the parasternal short-axis view (SAX). Results: A total of 700 healthy subjects (mean age: 9.53 ± 5.95 years; range: 1 day–17.98 years) were prospectively enrolled. The distance of the RCA and LMCA from the aortic annulus correlated with body surface area, and nomograms (Z-scores) were generated. The RCA origin was below the sinotubular junction (STJ) in 605 patients (86.43%), at the STJ in 66 patients (9.43%), and above the STJ in 29 patients (4.14%). The LMCA origin was below the STJ in 671 patients (95.86%), at the STJ in 12 patients (1.71%), and above the STJ in 17 patients (2.43%). With respect to the RCA, an emergence angle < 18.5° in the SAX predicted a high take-off. with a sensitivity of 98.3% and a specificity of 93.1% (AUC 0.998). With respect to the LMCA, an emergence angle > 119.5° in the SAX predicted a high take-off, with a sensitivity of 70.6% and a specificity of 82.4% (AUC 0.799). Conclusion: This study establishes nomograms for LMCA and RCA origin in standard echocardiographic projections in healthy children.

Prosthetic emergence angle in different implant sites and their correlation with marginal bone loss: A retrospective study

Background/purposeThe impact of prosthetic contour on peri-implant health has attracted increasing attention. This study aimed to evaluate the emergence angles in different implant sites and analyze the correlation between emergence angle and marginal bone loss (MBL). Materials and methodsSingle-crown implants with at least 5 years of follow-up were investigated in this retrospective study. Emergence angles and MBL were measured via digital radiography. The differences in emergence angles in different implant sites were analyzed using a one-way analysis of variance. Mann–Whitney U test was used to analyze the differences in MBL between groups (emergence angle> 30° and ≤30°), and Spearman's rank analysis was used to analyze the correlation between emergence angle and MBL. ResultsA total of 502 single-crown implants were included. For the mean mesial and distal emergence angles of different implant sites, the anterior position were 21.67 ± 10.80 (°) and 22.48 ± 12.78 (°), and the premolar were 26.29 ± 12.78 (°) and 24.30 ± 10.07 (°), and the molar were 34.53 ± 13.27 (°) and 34.48 ± 13.58 (°) respectively. The emergence angles of molar implant sites were significantly greater than those of anterior and premolar (P < 0.001). The Mann–Whitney U test and Spearman's rank analysis revealed that there was no correlation between emergence angle and MBL. ConclusionThere were significant differences in the emergence angles at different implant sites. However, when considering factors such as different sites or types of implants, there was no correlation between emergence angle and MBL, and more comprehensive research should be conducted in the future.

Soft tissue phenotype modification impacts on peri-implant stability: a comparative cohort study.

Soft tissue phenotype modification (STPM) could be performed to maintain peri-implant health. Therefore, the aim of the study was to analyze tissue alteration around implants following soft tissue phenotype modification during implant uncovering surgery. Patients who had STPM (either pouch roll or modified roll technique) during implant second-stage surgery with at least 12-month follow-up were included. Clinical and radiographic parameters including mucosal tissue thickness (MTT), recession (REC), keratinized mucosa width (KMW), probing pocket depth (PPD), marginal bone loss (MBL), emergence profile, and emergence angle were extracted from 2-week, 2-month, and 12-month visits after second-stage surgery. Twenty-eight patients with 33 implants that fulfilled the inclusion criteria were included. After soft tissue phenotype modification, at 2weeks, REC was negatively correlated to mean MTT at mid-buccal site (r = - 0.41, p = 0.018) and borderline correlated at mid-lingual site (r = - 0.343, p = 0.051). Stable KMW was maintained from 2weeks to 12months with minimal shrinkage rate (3 ~ 14%). MBL change was limited (0.24 ~ 0.47mm) after STPM. All implants had shallow PPD (≤ 3mm) with the absence of bleeding on probing. Emergence angle at the mesial side, however, was significantly correlated to surgical techniques, which indicated pouch roll technique would have 6.96 degrees more than modified roll technique (p = 0.024). Soft tissue phenotype modification, either pouch roll or modified roll technique, during uncovering surgery resulted in favorable clinical outcomes. Thin mucosal tissue thickness and pouch roll technique are the factors related to more recession at 2weeks. Pouch roll technique could influence the restorative design by having a wide emergence angle at the mesial side. Modified and pouch roll techniques during uncovering surgery were viable methods to yield favorable peri-implant health, while the preciseness of pouch roll technique was required to avoid mucosal recession and inadequate restorative design.

Morphology of Peri-Implant Tissues Around Permanent Prostheses With Various Emergence Angles Following Free Gingival Grafting.

To analyze the tissue morphology around implant-supported prostheses by digital technology and to evaluate the effect of prosthetic contours on the changes in tissues following the free gingiva graft procedure. A total of 53 implants in 32 patients receiving free gingiva grafts were selected. These had previously presented insufficient keratinized mucosa width (KMW). At the follow-up visits (mean: 16.66 ± 9.97 months), the implant position and tissue condition were documented with an oral scanner. Vertical soft tissue thickness (VT), measured from the implant-abutment connection to the marginal tissues, and horizontal soft tissue thickness (HT), at the level of the platform, were calculated. The VT, HT, and emergence angle (EA) of prostheses were assessed by 3Shape analyzing software. The final KMW was measured by clinical assessment. Marginal bone loss (MBL) was calculated in the follow-up bitewing radiographs. The mean VT in the study was 2.65 ± 0.75 mm at the mid-buccal sites, 3.74 ± 1.22 mm at the mesial, 3.16 ± 1.08 mm at the distal, and 2.53 ± 0.92 at the mid-lingual aspects. The mid-buccal HT was 1.45 ± 0.53 mm while the mid-lingual was 1.05 ± 0.43 mm (p = 0.008). Interestingly, prostheses with mid-buccal EA 30° exhibited slightly lower VT, but higher HT, than the ones with EA 30°. Prostheses with proximal EA > 30° displayed slightly more MBL, compared to prostheses with EA 30°. The mean KMW was 4.08 ± 1.10 mm. Free gingival grafting is a predictable treatment approach to augmenting soft tissue 3-dimensionally. Prostheses with EA 30° were preferable for preserving the maximal VT and maintaining crestal bone stability.

Depth of mucosal tunnel in peri-implant health during 12-month follow-up in patients with controlled periodontitis.

The association between thickness of peri-implant mucosa, known as mucosal tunnel (MT) and related clinical parameters in bone-level implants has not been investigated. Posterior implants, in patients with controlled periodontitis, were evaluated at different time intervals: during uncovering surgery (T0 ), 2-month after uncovering surgery (T2M ) and 12-month after placement (T12M ). Clinical parameters including vertical soft tissue height (VSTH), MT, tooth-implant discrepancy of bone level (DBL), pocket depth (PD), peri-implant marginal bone loss (MBL), emergence profile and emergence angle (EA) were collected, and the correlation were assessed at different time points. Forty-two patients with 60 implants were recruited, and 81.7% of the patients were Stage III-IV, Grade B-C generalized periodontitis. MT presented no significant difference in PD, VSTH, and MBL. Periodontitis Grade C and absence of bone regeneration were significant predictors for deep MT (>3mm), and 5.850 less EA at mesial side of implants (p=0.02).The regression of analysis implied the increase of DBL 1mm would cause 0.26mm deeper MT, 1.7 times higher risk of having deep MT (p=0.041; OR=1.731; 95% CI:1.02-2.93) and 2.1 times higher risk of having circumferential PD>4mm (p=0.019; OR=2.1; 95% CI:1.13-3.92). In bone-level implants, a correlation between MT and clinical parameters at 12-month follow-up was not found. However, history of periodontitis Grade C, absence of bone regeneration and tooth-implant discrepancy of bone level might define the depth of MT. Additionally, the depth of MT played a critical role in determining restorative design.

Implant-abutment emergence angle and profile in relation to peri-implantitis: A systematic review.

StatementThe aim of this systematic review is to analyze literature regarding the relationship between the implant‐abutment emergence angle (EA) and implant emergence profile (EP) and the prevalence of peri‐implantitis.MethodsPubMed and the Cochrane Library were searched for studies from initiation up to April 2022. Studies describing the EA and EP in association with peri‐implantitis were considered eligible for this review and selected for inclusion in this review if implant groups with wide and narrow EA and different EP types were described.ResultsSearches in PubMed and the Cochrane Library led to 1116 unique titles and the inclusion of three studies. These concerned 168–349 implants. Two studies presented the mean prevalence of peri‐implantitis which was 16.7% and 24.8% at the implant level. Both studies showed a significant relationship between peri‐implantitis in bone‐level implant groups with an EA above 30° compared to implants with an EA below 30°. A third study presented marginal bone loss which tended to be smaller when the EA was around 20°–40°. In one of the three included studies, the prevalence of peri‐implantitis was significantly higher if implants had a convex EP compared to a concave or straight EP. Another study showed a significantly higher prevalence of peri‐implantitis in implants with a convex EP compared to other EP types, if combined with an EA above 30°.ConclusionsThree eligible studies were found. Reported associations should therefore be considered with caution. Synthesis suggests an association between a larger EA (>30°) and a higher prevalence of peri‐implantitis or marginal bone loss compared to a smaller EA (<30°). A convex EP may also be associated with a higher prevalence of peri‐implantitis. However, causality remains a question.

Rotational Positioning of One-piece Implants in Computer-Guided Flapless Surgery and Immediate Loading Using the All-on-4 Concept

The aim of this clinical application is to assess the procedure of simultaneous insertion and rotational positioning of the one-piece implant (implant + Multi-Unit-Abutment) in order to achieve the right emergence angle of the abutment using reference points on the surgical guide. This clinical procedure is particularly useful in cases of immediate loading using the All-on-4 concept. The case is designed through dedicated software by virtually inserting the implants in the optimal position with respect to the prosthesis and the bone situation. The program automatically determines the position of the bushing and virtual modeling, printing and gluing of the bushing to the surgical guide are performed. The procedure ensures correct integrated Multi-Unit-Abutment rotational positioning done in one movement using both implant contra-angle or manual insertion. Results are appreciable both for the precision of the abutment emergence angles for prosthetic long-term biomechanical stability and for the absence of bacterial microfiltration in the abutment/implant interface. The clinical sequence is easy for the surgeon and time-saving. The surgeon is less stressed-out and the time needed is much less than standard procedure with Multi-Unit-Abutments screwing. This is facilitated by the reference points on the bushing. At the same time, further scientific evidence is needed and also the procedure must be integrated with the drilling undersized protocol for achieving the proper primary stability for All-on-4 immediate loading purposes. We think that this application needs clinical attention for reducing chair-time and stress-related procedures.