Relative Placement Research Articles

Structure-Photochemical Function Relationships in the Photobasicity of Aromatic Heterocycles Containing Multiple Ring Nitrogen Atoms.

Photobases are compounds that become more basic when promoted to an excited electronic state. Previous experimental and computational studies have demonstrated that several quinoline and quinoline-derived compounds are strong photobases (pKa* > 14). Moreover, the strength of photobasicity was shown to depend strongly on the identity and position of the substituent group(s), with the strongest photobases having multiple electron-donating substituents on a fused benzene ring as opposed to the ring containing the photobasic nitrogen atom. These electron-donating substituents build up electron density on one side of the molecule that shifts onto the nitrogen-containing ring in the electronic transition. This shift in electron density produces an increase in negative charge on the ring nitrogen atom responsible for the photobasicity. In this paper, we expand on our previous investigation to study the effect of an additional ring nitrogen atom on photobasicity in aromatic heterocycles. In particular, we consider how the thermodynamic driving force for excited-state protonation can be tuned by changing the relative placement of the ring nitrogen atoms and varying the position and number of electron-donating substituents. In the set of 112 molecules screened, we identified 42 strong photobases with generally comparable pKa* but lower vertical excitation energies than the quinoline derivatives with only a single ring nitrogen atom. We additionally explored photobasicity in substituted azaindole and carboline derivatives, identifying 76 strongly photobasic compounds with pKa* as large as 22.6 out of the 155 compounds that we considered. Overall, this work provides new insights into the design principles necessary to develop next-generation photocatalysts that employ photobasicity.

Void Growth and Interaction in a Structural Aluminum Alloy: Experiments and Theory

The problem of void growth and interaction is of importance to understanding the mechanics of failure in metals exhibiting ductility. In this work, the growth and interaction of voids in 6061-T6 aluminum were studied experimentally. Specifically, holes of varying numbers and relative placement were investigated for their normalized area growth with applied displacement. Flat dog-bone specimens were carefully drilled in their gauge area with no (zero) holes, one hole, and two holes (arranged vertically or horizontally) for experimentation after polishing. The growth of holes, captured by video recordings, exhibited exponential behavior and was influenced greatly by the number and arrangement of holes with the horizontal voids growing the fastest and the vertical ones growing the slowest. Also, the ensuring deformation of the sample was studied using load-displacement curves, pictography and videography, SEM imaging and Atomic Force Microscopy (AFM). The methods revealed that although the major part failure is due to large crack formation, it was preceded by intense dislocation slip activity and the formation of micro cavities. Also, the AFM quantified the three-dimensional nature of crystal or grain deformation and how it is greatly influenced by distance and location from the hole. Lastly, theoretical understanding of hole growth was offered.

Recent advances on the synthesis of flavans, isoflavans, and neoflavans

AbstractHeterocyclic compounds are the omnipresent structural cores comprising many natural and pharmaceutical products of biological significance. Significantly, heterocyclic compounds are widely distributed in nature, and also have applications in agrochemicals, sanitizers, as dyestuff, as copolymers, etc. Among heterocyles, flavonoids are a class of compounds that are highly interesting and constitute many natural products. In general, all flavanoids contains a basic core of C6‐C3‐C6 of phenyl‐benzopyran backbone. The relative placement of the phenyl group on to the benzopyran core makes further classification into flavanoids, isoflavanoids and neoflavanoids. Flavans (2‐aryl chroman) are subclass of anthoxanthanes exhibits a broad spectrum of biological properties such as anti‐inflammatory, anti‐oxidant, and anti‐malarial properties. Some representative naturally occurring products possessing flavan core are apigenin, luteolin, tangeretin, scutellarein, etc. On the other hand, some of the notable isoflavan‐based natural products are glabridin and (S)‐(−)‐equol. Glabridin is isolated from Licorice roots, which regulates paraoxonase (PON2) levels. While the simple isoflavan (S)‐(−)‐equol, is produced from soy isoflavone intake. Also, natural products such as dalbergichromene, centchroman, and (+)‐myristinin A possess neoflavan (4‐aryl‐3,4‐dihydro‐2H‐chromenes) core structure. Owing to their broad biological and pharmacological properties, synthetic chemists are fascinated in developing new routes toward their synthesis. As a result, a decent number of reports have been established in the literature. Thus, for the past 5 years of time frame, many new methodologies have been witnessed, for the synthesis of various flavan systems. This review emphasizes most of the significant methods on accomplishing flavans, isoflavans and neoflavans and also focused on their applications to the synthesis of relevant natural as well as biologically active products.

Predictors and rates of prior endoscopic tattoo localization amongst individuals undergoing elective colorectal resections for benign and malignant lesions

Appropriate tattooing of suspicious lesions during colonoscopy is critical for surgical planning. However, variability exists in tattoo placement, technique, and reporting. Our aim is to determine the rates and predictors of tattoo placement, tattoo location in relation to the lesion, and localization accuracy during lower endoscopy for individuals undergoing elective colorectal resections. We performed a retrospective chart review on all patients undergoing elective colorectal resections for benign and malignant neoplasms between 2007 and 2017 at a high volume Canadian tertiary centre. Patient demographics, endoscopic, and tumour-related characteristics were collected. Multivariable logistic regression analysis was used to identify predictors of tattoo localization. Of the 1062 patients identified, laparoscopic resection occurred in 59% of patients. 57% of patients underwent tattooing for tumour localization at index endoscopy. Tattoos were placed distal (27%), both proximal and distal (4%), and just proximal (2%) to the lesion. However, in the majority of cases the tattoo location was not documented (67%). On multivariate analysis, patients who had lesions located in the transverse colon (OR: 1.93, 95% CI 1.04-3.59), had surgery performed after 2010 (2011-2014: OR: 1.88, 95% CI 1.31-2.68; 2015-2017: OR: 2.87, 95% CI 1.93-4.26), underwent laparoscopic resections (OR: 1.69, 95% CI 1.22-2.33), and had their index endoscopy performed in an urban setting (OR: 5.92, 95% CI 3.23-10.87), were at higher odds of having a tattoo placed at index endoscopy. Endoscopic tattoo placement and location in relation to the lesion varies widely, with reports containing suboptimal documentation. Lesion location and laparoscopic procedures were significant predictors of tattoo placement. This study highlights the need for standardized tattooing practices and reporting amongst endoscopists. One of the focus of quality improvement efforts should be educational initiatives for rural endoscopists.

Finding the bird’s wings: Dimensions of factional conflict on Twitter

Intra-party politics has long been neglected due to lacking data sources. While we have a good understanding of the dynamics of ideological competition between parties, we know less about how individuals or groups inside parties influence policy, leadership selection and coalition bargaining. These questions can only be answered if we can place individual politicians and sub-party groups like factions on the same dimensions as in inter-party competition. This task has been notoriously difficult, as most existing measures either work on the party level, or are in other ways determined by the party agenda. Social media is a new data source that allows analyzing positions of individual politicians in party-centered systems, as it is subject to limited party control. I apply canonical correspondence analysis to account for hierarchical data structures and estimate multidimensional positions of the Twitter accounts of 498 Members of the German Bundestag based on more than 800,000 tweets since 2017. To test the effect of intra-party actors on their relative ideological placement, I coded the faction membership of 247 Twitter users in the Bundestag. I show that Twitter text reproduces party positions and dimensions. Members of factions are more likely to represent their faction’s positions, both on the cultural and the economic dimension.

Intragastric balloon placement in the treatment of overweight and obesity: Experience at a Mexican referral center

Introduction and aimIntragastric balloon therapy is a temporary, minimally invasive method for inducing weight loss. Any balloon with a volume of 400 ml induces satiety and delayed gastric emptying. The aim of the present study was to demonstrate its safety and efficacy. Materials and methodsWe analyzed the safety and effectiveness of balloon placement in relation to weight loss in 128 patients. Subgroups were compared through the Student’s t test, ANOVA test, and the chi-square test, depending on the type of variable and the number of groups evaluated. Statistical significance was set at a p ≤ 0.05 to evaluate weight loss. ResultsMean weight loss after balloon therapy was 10.7 kg, with only 2 cases of complications due to oral feeding intolerance. Mean length of time with the balloon was 8 months. There were no complications after 6 months, but no further weight loss either (p = 0.540). Final weight loss versus initial weight loss was significant (p = 0.000). There was greater weight loss in the group that attended the bimonthly control appointments than in the group that did not: 12.7 kg vs. 7.26 kg (p = 0.000). ConclusionsThe rates of the adverse events of intolerance and complications were very low in our study, compared with results in the literature (1.6% vs. 4.7% and 0% vs. 3%, respectively). Intragastric balloon placement had better results when the patients attended the control appointments. Intragastric balloon therapy is a safe and efficacious method for reducing weight in patients with overweight and obesity.

Towards describing scenes by animals: Pigeons' ordinal discrimination of objects varying in depth.

The perception of a complex scene requires visual mechanisms that include identifying objects and their relative placement in depth. To examine apparent depth perception in birds, we tested four pigeons with a novel multiple-sequential-choice procedure. We created 3D-rendered scene stimuli containing three objects located at different apparent depths based on a variety of pictorial cues and placed small circular target response areas on them. The pigeons were trained to sequentially choose among the multiple response areas to report the object closest in apparent depth (ordinal position; front then middle object). After the pigeons learned this sequential depth discrimination, their use of three different monocular depth cues (occlusion, relative size, height in field) was tested, and their flexibility evaluated using three novel objects. In addition to the contribution to understanding apparent depth perception in birds, the use of more flexible open-ended choice discriminations, as employed here, has considerable promise for creating informative production-like tasks in nonverbal animals.

Trends of Implant Placement in Relation to Crestal Bone Level in a Private Dental Institute

Dental implants provide a strong foundation for fixed or removable prosthetic teeth that are made to match natural dentition. It has become an ideal method of oral rehabilitation after missing natural dentition has been recognised as a reliable tool for dental reconstruction and aesthetics. Marginal bone loss is characterized by a reduction in bone loss is characterized by a reduction in bone level both vertically and horizontally. The levels at which dental implants are placed include sub-crystal, equi-crestal, and supra-crestal. The crestal levels affect bone height significantly. Failure to do so will lead to peri-implant bone loss which will affect the implant function and ultimately implant failure. A retrospective study was conducted based on a university setting. 615 patients with 1141 implant sites were reviewed from June 2019 to March 2020. Excel tabulation and SPSS analysis were done for data analysis. There was a statistically significant difference between the variables that included tooth region, crestal relation and site (jaw)—[p-value<0.05] The most common crestal relation of implant placement is equi-crestal implant placement. The assessment of trends of implant placement in relation to crestal bone level shows that equi-crestal implant is the most preferred crestal relation of implant placement in Saveetha Dental College.

Bud Powell’s Improvising and the Aesthetics of Bebop Rhythm

ABSTRACT This article explores the ways in which Bud Powell’s improvising embodies and contributes to the aesthetics of bebop rhythm. Special attention is paid to the relationship between Powell’s music and the textural developments of the rhythm section, especially advances in jazz drumming and the underlying harmonic rhythm as temporal reference. Topics include asymmetry of phrase placement and structure in relation to meter and cyclic form, irregular accents and left-hand “bombs,” beat-one avoidance and negative accents, harmonic displacement, phrasing “over the barline,” and cross-rhythmic groupings.

Ultrasonic augmentation in pool boiling heat transfer over external surfaces: A review

Boiling heat transfer is known for high heat fluxes at relatively small temperature differences. However, over the decades, technological innovations have demanded further augmentation in heat fluxes associated with boiling. Among the various active and passive methods, use of ultrasonic waves in boiling liquid has emerged as a proven technique for the required heat transfer improvement as demonstrated by a number of researchers. The present article reviews the application of ultrasonic waves in enhancing the heat transfer in various regimes of pool boiling. It has been found that the use of ultrasonic field is more promising in case of sub-cooled boiling as compared to saturated condition. Along with ultrasonic field of lower frequency and higher power, the usage of various passive techniques of surface improvement such as micro channel, surface topology, nano coatings etc. leads to further augmentation of heat transfer. Also, the relative placement of heating surface in ultrasonic wave field must be considered inevitably while designing an ultrasonic field assisted pool boiling system. It requires further investigations to conduct more parametric studies such as effect of pressure along with the usage of ultrasonic waves during sub- cooled boiling. Also during ultrasonic assisted pool boiling, various nano fluids can be tested for improving the heat transfer characteristics particularly in the saturated nucleate boiling regime.

Very few sites can reshape the inferred phylogenetic tree.

The history of animal evolution, and the relative placement of extant animal phyla in this history is, in principle, testable from phylogenies derived from molecular sequence data. Though datasets have increased in size and quality in the past years, the contribution of individual genes (and ultimately amino acid sites) to the final phylogeny is unequal across genes. Here we demonstrate that removing a small fraction of sites strongly favoring one topology can produce a highly-supported tree of an alternate topology. We explore this approach using a dataset for animal phylogeny, and create a highly-supported tree with a monophyletic group of sponges and ctenophores, a topology not usually recovered. Because of the high sensitivity of such an analysis to gene selection, and because most gene sets are neither standardized nor representative of the entire genome, researchers should be diligent about making intermediate analyses available with their phylogenetic studies. Effort is needed to ensure these datasets are maximally informative, by ensuring all genes are systematically sampled across relevant species. From there, it could be determined whether any gene or gene sets introduce bias, and then deal with those biases appropriately.

The communicative function of adjective-noun order in English

The problem undertaken here is to account for the relational placement in English of words traditionally known as adjectives and nouns. Two distinct orders are examined as signals of discrete meanings: one where the characterizing word is preposed to the characterized word, as in long hair, and the other where it is postposed, as in hair long. Distribution of the two signals in attested text is accounted for under the hypothesis that an Assertion of Characterization is made weaker or stronger, respectively, through this word order. With these meanings, a writer draws a distinction between Characterization the writer assumes the reader will receive as uncontested and so requires weaker Assertion and Characterization which is selected out of an array of particularly relevant possibilities and so requires stronger Assertion.

Feasibility Study of an Automated Assembly Process for Ultrathin Chips.

This paper presents a feasibility study of an automated pick-and-place process for ultrathin chips on a standard automatic assembly machine. So far, scientific research about automated assembly of ultrathin chips, with thicknesses less than 50 µm, is missing, but is necessary for cost-effective, high-quantity production of system-in-foil for applications in narrow spaces or flexible smart health systems applied in biomedical applications. Novel pick-and-place tools for ultrathin chip handling were fabricated and a process for chip detachment from thermal release foil was developed. On this basis, an adhesive bonding process for ultrathin chips with 30 µm thickness was developed and transferred to an automatic assembly machine. Multiple ultrathin chips aligned to each other were automatically placed and transferred onto glass and polyimide foil with a relative placement accuracy of ±25 µm.

Monitoring coastal morphology: the potential of low‐cost fixed array action cameras for 3D reconstruction

AbstractThe combination of structure‐from‐motion with multi‐view stereo (SfM‐MVS) photogrammetry has become an increasingly popular method for the monitoring and three‐dimensional (3D) reconstruction of coastal environments. Climate change is driving the potential for increased coastal landward retreat meaning geomorphological monitoring using methods such as SfM‐MVS has become essential for detecting and tracking impacts. SfM‐MVS has been well‐researched with a variety of platforms and spatial and temporal resolutions using mainly rectilinear digital cameras in coastal settings. However, there has been no assessment of the potential of fixed multi‐camera arrays to monitor landward retreat or on the significance of camera placement in relation to the scene. This study presents an innovative method of image acquisition using a purpose‐built camera grid and GoPro© action camera to evaluate the combined effects of camera height, obliqueness and overlap at a site of known landward retreat. This approach examines the effect of camera placement on scene reconstruction to aid the design of a multi‐camera array. SfM‐MVS dense point clouds display millimetre accuracy when compared to equivalent terrestrial laser scans and strong image network geometry with internal precision estimates of < 3 mm. Comparable point cloud reconstruction can be achieved with a small number of images stationed in appropriate positions. Initial results show as few as five images positioned at a cliff to camera ratio of 3:4.18 and camera obliqueness of 40° can provide reconstruction in the range of millimetres (mean error of 4.79 mm). These findings illustrate the importance of camera placement when using multiple cameras and aid the design of a low‐cost, fixed multi‐camera array for use at sites of small‐scale landward retreat. © 2020 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd

Unravelling the Chemistry of the [Cu(4,7-Dichloroquinoline)2Br2]2 Dimeric Complex through Structural Analysis: A Borderline Ligand Field Case

Large dark prismatic crystals (P 1 ¯ ) consisting of closely packed centrosymmetric [Cu(4,7-dichloroquinoline)2]2Br4 binuclear units are formed when 4,7-dichloroquinoline (DCQ, C9H5NCl2) binds copper(II). Cu2+ adopts a strongly distorted square pyramidal coordination geometry, perturbed by electrostatic interactions with two axial μ–Br ligands acting as highly asymmetric bridges. It is shown that, as electronic states of ligands are higher in energy than the metal ones, antibonding orbitals bear significant ligand-like character and electronic charge is partially transferred from inner-sphere coordinated halogen atoms to copper. Overall, the title compound sits on the Hoffman’s border between main group and transition chemistry, with non-negligible contributions of the ligands to the frontier orbitals. The relative energy placement of metal and ligand states determines an internal redox process, where the metal is slightly reduced at the expense of partial oxidation of the bromide ligands. In fact, the crystal structure is partially disordered due to the substitution of some penta-coordinated Cu(II) centers with tetra-coordinated Cu(I) ions. The geometry of the complex is rationalized in terms of electrostatic-driven distortions from an ideal octahedral prototype. Implications on the reactivity of Cu(II)–quinoline complexes are discussed.

Stenting the ureteroneocystostomy reduces urological complications in kidney transplantation: a noninferiority randomized controlled trial, SPLINT trial.

The role of ureteral stents in living-donor kidney transplantation remains uncertain. In this randomized controlled trial (SPLINT), we compared urological complications in living-donor kidney transplantations performed with or without stents. We included 200 consecutive patients that received living-donor kidney transplantations at the Erasmus MC, University Medical Center, Rotterdam. Patients (124 males, 76 females, mean age 54±13) were randomized for suprapubic externalized single J stents (N=100) or no stent (N=100). The primary outcome was the probability of a percutaneous nephrostomy insertion (PCN) during a 12-month follow-up. To assess whether no stenting is noninferior to stenting, we allowed the probability of a PCN to increase by at most 5% (this is the noninferiority margin). Baseline characteristics were comparable between groups. In the no-stent group, there were more PCN insertions, 14% (95% CI 4.3-23.7%); urinary leakages, 12% (95% CI 5.4-21.3%); and surgical re-interventions because of urological complications, 8% (95% CI 1.5-14.5%). The stent group had more hematuria, 26% (95% CI 13.1-38.9%); and graft rejections, 15% (95% CI 2.7-27.3%). Patients in both groups had similar mean GFRs at several time points. Besides a better Euro-Qol-5D in the no-stent group at 2 and 6weeks postoperative, similar quality of life was reported based on SF-36 and Euro-Qol-5D scores. In this trial, noninferiority has not been demonstrated for no-stent placement in relation to the number urological complications.

A Comparison of Complications and Clinical and Radiologic Outcome Between the Mini-open Prepsoas and Mini-open Transpsoas Approaches for Lumbar Interbody Fusion

Systematic review and meta-analysis. To compare complication rates and clinical and radiologic outcome between the mini-open prepsoas and mini-open transpsoas approaches for lateral lumbar interbody fusion. Both approaches are believed to be safe with similar complication rates. Previous studies suggest that the rate of neurological injury might be higher in the transpsoas group, whereas visceral or vascular injury might be more frequent in the prepsoas group. A systematic review of the literature was performed. Data were extracted from original publications up until December 26, 2018. Evidence was extracted from well-designed case-control or cohort studies and sorted in 2 groups, the prepsoas and transpsoas approaches. A meta-analysis was performed using a random-effects model (I statistic >50% for all analyses). A total of 115 studies included data of 13,260 patients, 2450 in the prepsoas group and 10,810 in the transpsoas group. Demographics for prepsoas versus transpsoas group were (N-weighted means): age 61.9 versus 60.9 years; %female sex 53% versus 63%, levels fused 1.4 versus 2.6, blood loss 52.4 versus 122.3 mL, and operating time 125.1 versus 200.7 min. The following statistically significant differences in complication rates between prepsoas and transpsoas approaches were found: transient psoas weakness or thigh/groin numbness 4% versus 26% [95% confidence interval (CI): 11%-17%], motor neural injury 0.4% versus 1.3% (95% CI: 16%-62.3%); no statistically significant differences were found for: major vascular injury 2% versus 1% (95% CI: 1.04%-2.31%), kidney or ureter injury 0.04% versus 0.08% (95% CI: 0.057%-5.2%), injury pleural/peritoneal structures 0.6% versus 0.2% (95% CI: 0.89%-6.58%), cage subsidence 5% versus 4% (95% CI: 0.9%-1.97%), surgical site infection 1% versus 1% (95% CI: 0.57%-1.66%), abdominal wall pseudohernia 1% versus 1% (95% CI: 0.07%-21.22%), sympathetic chain injury 5% versus 0% (95% CI: 0.34%-97.86%), and directly procedure-related death 0.04% versus 0% (95% CI: 0.127%-76.8%). Pooled mean perioperative changes between prepsoas and transpsoas approaches were: segmental sagittal Cobb angle 3.07 versus 1.99 degrees; foraminal height 2 versus 6.96 mm. The prepsoas had fewer complications than the transpsoas approach. Furthermore, the prepsoas approach showed superior restoration of segmental lordosis, whereas foraminal height restoration was superior with the transpsoas approach. This could be explained by the differences in location of the interbody device placement in relation to the center of rotation of the spine between the 2 surgical techniques.

Effects of training on truck drivers\u2019 interaction with cyclists in a right turn

With encounters between trucks and cyclists still being a major safety issue and physical as well as technological improvements far from ubiquitous implementation, training truck drivers in anticipatory driving to improve their interaction with cyclists may be a way forward. After a baseline drive in an urban environment, truck drivers inexperienced with urban driving received a dedicated training on anticipatory driving, followed by another drive along the same route several weeks later. The drivers were also interviewed about their opinion about the training. The drivers’ behaviour changed from before to after training, resulting in a better speed management in general, and a more intensive monitoring of the cyclists. There were also some improvements with respect to the placement in relation to the cyclist, but this effect was limited mainly because truck drivers performed well already before the training. The observed results correspond well to the opinions and feelings about the training that were reported by the drivers in the interview. Thus, driver training can possibly be one contributor to an increase in safety in urban areas.

Is There an Optimal Recovery Step Landing Zone Against Slip-Induced Backward Falls During Walking?

Recovery stepping in response to forward slips has the potential to not only rebuild the base of support to prevent backward falling, but also provide extra limb support to prevent downward falling. Hence, recovery stepping is often necessary for fall prevention following an unexpected slip. However, less is known about whether recovery foot placement could affect the likelihood of recovery following a slip. The purpose of this study was to determine whether there is an optimal recovery landing zone within which older adults have a higher likelihood of recovery. 195 participants experienced a novel, unannounced forward slip while walking on a 7-m walkway. The center of mass (COM) stability (computed from its position and velocity), vertical limb support (computed from change in hip kinematics), and recovery limb joint moments (computedfrom joint kinematics and ground reaction force) in the sagittal plane were analyzed. The results showed that a longer distance between recovery foot landing position and the projected COM position at recovery foot touchdown (relative recovery step placement) was conducive to stability improvement but adverse to limb support enhancement, and vice versa for a shorter distance. Relative recovery step placement could predict the recovery likelihood with an accuracy of 67.3%, and the recovery rate was greater than 50% when the distance between recovery foot and COM is less than 0.3 × foot length. This study also found more posterior stepping could be attributed to insufficient ankle plantar flexor and hip flexor moments in the pre-swing phase, while more anterior stepping was induced by insufficient hip and knee extensor moments in the following swing phase.

Accuracy of static computer-assisted implant placement in anterior and posterior sites by clinicians new to implant dentistry: in vitro comparison of fully guided, pilot-guided, and freehand protocols

BackgroundOne of the challenges encountered by clinicians new to implant dentistry is the determination and controlling of implant location. This study compared the accuracy of fully guided (FG) and pilot-guided (PG) static computer-assisted implant placement (sCAIP) protocols against the conventional freehand (FH) protocol for placing single anterior and posterior implants by recently introduced clinicians to implant dentistry.Material and methodsTen clinicians new to implant dentistry inserted one anterior (central incisor) and one posterior (first molar) implants per protocol in training maxillary models. The FG protocol involved drilling and implant placement through the guide, while the PG protocol controlled the pilot drilling only. The FH implant placement was completed without the aid of any guide. A total of 30 models were used, and 60 implants were inserted. The implant vertical, horizontal neck, horizontal apex, and angle deviations from planned positions were calculated.ResultsThe FG protocol provided the most accurate implant placement in relation to horizontal neck (0.47 mm–0.52 mm), horizontal apex (0.71 mm–0.74 mm), and angle deviations (2.42o–2.61o). The vertical deviation was not significantly different among the different protocols. The PG protocol was generally similar to the FH protocol with a horizontal neck deviation of 1.01 mm–1.14 mm, horizontal apex deviation of 1.02 mm–1.35 mm, and angle deviation of 4.65o–7.79o. The FG protocol showed similarity in the accuracy of the anterior and posterior implants. There was a tendency for inferior accuracy for posterior implants compared with anterior implants for the PG and FH protocols.ConclusionsIn the hands of recently introduced clinicians to implant dentistry, it appears that the accuracy of the FG protocol was superior to the other protocols and was not influenced by the position of the implants. The PG and FH protocols showed inferior accuracy for posterior implants compared with anterior implants.