Radiopaque Material Research Articles

430 CT Imaging Of Gadolinium And Iodine Doped Bioresorbable Vascular Scaffolds

Introduction: Radiographic visualization of vascular scaffolds provides potential advantages during initial deployment and follow-up assessments. However, bioresorbable scaffolds are typically not constructed from radiopaque materials and image interpretation is often complicated by adjacent vascular calcifications and iodinated intravascular contrast. One strategy to achieve fluoroscopic and CT-based visualization of bioresorbable polymeric scaffolds is to dope them with radiopaque additives. Gadolinium (Gd) and iodine (I) are potentially useful radiopaque dopants for polymeric bioresorbable scaffolds due to their established biocompatibility.

Lower jaw virtual reposition accuracy research

The aim is to study of the accuracy of the virtual reposition of the mandible (LF) by comparing the virtual and real position of the LF heads, as well as the analysis of factors contributing to the occurrence of errors. An experimental model of a human skull with a movable LF was made of radiopaque material. The resulting computed tomogram (CT) of the upper and lower jaws and temporomandibular joint (TMJ) was combined with dental scans of dental rows and CT scans and a report on the position of the heads of the LF was obtained. Then the LF was shifted to another position and this position was fixed. Optical bite recorders were obtained using an intraoral scanner. An experimental model with a fixed new position of the LF was placed in a tomograph and repeated CT was obtained. In the program, according to optical registers, a virtual reposition of the LF was carried out. The correspondence of the virtual and real position of the mandibular heads was compared. The absolute difference of glenoid fossa space between the actual and virtual reconstruction was 0.542±0.3354 mm in the anterior joint section (M±δ, M - average mean, δ - standard deviation); for the upper joint section - 0.309±0.2246 mm; and 0.260±0.1862 mm for the posterior section. The integral indicator of surface coincidence (q) when the virtual and actual position are directly compared was 0.296±0.1254 (s.u.). The total margin of error depends on the following factors: repeated scanning error (teeth arches and bite scans), repeated CBCT error, a combination of scan and CBCT error, a combination of teeth arch scan and bite scan error, error of TMJ separation. The latter two factors were the most significant.

Radiographic evaluation of a novel bone adhesive for maintenance of crestal bone around implants in canine oversized osteotomies.

A novel bone adhesive (tetracalcium phosphate and O-phospho-L-serine) has been developed as an osteoconductive, biodegradable bone-adherent material. The purpose of this study was to evaluate the maintenance of crestal bone/material level by standardized radiographs. This was a randomized, controlled, three arm, prospective study. Twenty-six mixed breed hound dogs were included in this study. Three implants were placed on either side of the mandible with either bone adhesive (BA), bovine bone mineral (BBM), or no biomaterial (negative control [NC]). Standardized periapical radiographs were taken immediately after implant placement and at every month up to 1 year. The vertical distance between the implant platform to the first radiopaque material on both the mesial and distal surfaces were measured and crestal bone/material level changes were analyzed. The crestal bone/material level adjacent to BA was stable and maintained throughout the study. There were statistically significant differences found between BA and NC in terms of maintenance of crestal bone levels at any given timepoint. This study demonstrated that BA maintained crestal bone levels and had a similar ability to maintain that level over 1 year compared with BBM.

3D-printing for the precision assessment of a new medical device

Additive manufacturing played a keyrole in investigating the precision of a recently-developed device that measures the elastic characteristics of the trabecular bone by simulating the application of loads on a virtual biopsy obtained from radiographic images of the proximal epiphyses in the patient’s hand fingers. The simulation results are combined in a Bone Structure Index (BSI), which has shown to be able to detect trabecular bone alterations due to osteoporosis or other pathological situations. In order to obtain a large number of measurements without having voluntary patients undergo unnecessary radiations, the precision assessment tests were carried out on a 3D-printed phantom hand, in which different mimicked trabecular structures (chips) were inserted. Each mimicked bone had a unique internal structure and density and was 3D-printed using radiopaque composite materials. Fifteen different chips were additively manufactured; 20 measurements were performed on each chip. BSI and BSI_T-score precision values were computed according to ISO 5725 and ISCD standards. For all the chips, no relationship was found between the mean [Formula: see text] and standard deviation [Formula: see text] of the measurements in each chip. The range of the 95% confidence interval ([Formula: see text]) was computed assuming the repeatability standard deviation [Formula: see text] as the known standard deviation of the measurement method (average of [Formula: see text] values): [Formula: see text], corresponding to [Formula: see text]. Least Significant Change was evaluated as well: [Formula: see text], corresponding to [Formula: see text]. The 95% confidence intervals are small when compared to the commonly-accepted diagnostic values, where a patient is classified as osteoporotic if T-score < −2.5, non-osteoporotic if T-score > -1 and osteopoenic if -2.5 < T-score < -1. The LSC results are in line with the requirements for the gold-standard osteoporosis diagnostic systems. Additive manufacturing made it possible to avoid irradiation of humans in this precision assessment.

Energy-Dispersive X-Ray Spectrometry Analysis and Radiopacity of Five Different Root Canal Sealers.

Root canal sealers should have optimum adhesion to the root dentin, low cytotoxicity, sufficient radiopacity and high dimensional stability, which depend mainly on their chemical composition. The aims of this study were to evaluate the chemical composition of Syntex (Cerkamed, Stalowa Wola, Poland), Adseal (Meta Biomed, Cheongju-si, Korea), Sealapex (SybronEndo, Scafati, Italy), MTA Fillapex (Angelus, Londrina, Brazil) and GuttaFlow Bioseal (Coltene/Whaledent, Altstätten, Switzerland) and to determine their radiopacity comparatively. Stainless steel molds with an inner diameter of 5 mm and a depth of 2 mm were constructed. Tested root-canal sealers were mixed and poured into the molds. Following setting, digital periapical radiographs of the specimens (n=12) were taken under standard exposure conditions and the mean gray-values of specimens were measured using a computer graphics program. Then the specimens were examined by scanning electron microscopy, and Energy-dispersive X-ray analysis was performed. The data were analyzed using One-way ANOVA followed by Holm-Sidak multi-comparison test (p = 0.05). Sealapex showed higher calcium peak than MTA Fillapex, GuttaFlow Bioseal, Adseal and Syntex sealers. MTA Fillapex contained a highest amount of tungstate. Sealapex presented the highest radiopacity value among the tested materials (p < 0.05), whereas MTA Fillapex was the least radiopaque material (p < 0.05). Each root canal sealer contains different compositions of radiopacifiers including bismuth oxide, calcium tungstate and zirconium oxide. The tested root canal sealers had radiopacity values above the ISO-specified limit. Sealapex was the most radiopaque root canal sealer followed by GuttaFlow Bioseal, Syntex, Adseal and MTA Fillapex.

Double visualization of root canal treatment with CBCT and microscope

In root canal retreatment, the outcome may not be always favorable in the standard procedure. Identification of the cause and direct approach to it may be a key point to success. A 58-year-old male patient visited Okaguchi dental clinic in Tokyo, Japan. His chief complaint was discomfort on the mandibular right second premolar. He had a slight percussion pain and sinus tract in this tooth. The dental X-ray showed a periapical lesion around the root canal-treated tooth. From CBCT images a radiopaque material was observed in periapical lesion. Gutta-percha was removed with ultrasonic files (Mani, Japan) and micro excavator (Seto, Japan) using microscope (Karl Zeiss, Germany). The radiopaque material in periapical lesion was also removed with micro excavator and it was gutta-percha. Root canal was filled with MTA (ProRoot MTA, USA). After treatment, all of his symptoms disappeared. At the 3-year follow-up, periapical lesion was completely healed. Clinicians usually treat blindly with hand or rotary files and 2-Dimensional X-ray. However, CBCT reveals more detailed information on the morphology and problems of the root canals. In this case, it was presumed that gutta percha outside the apical foramen also became an infection source. To perform all procedures visually, microscope, ultrasonic files and micro excavator were used. For the success of retreatment, it is important to identify the problem in each case and direct approach to it. Double visualization of endodontic treatment using CBCT and microscope is an ideal technique for root canal retreatment.

Microfluidic fabrication of imageable and resorbable polyethylene glycol microspheres for catheter embolization.

Radiopaque and degradable hydrogel microspheres have a range of potential uses in medicine including proper placement of embolic material during occlusion procedures, acting as inherently embolic materials, and serving as drug carriers that can be located after injection. Current methods for creating radiopaque microspheres are either unable to fully and homogeneously incorporate radiopaque material throughout the microspheres for optimal imaging capabilities, do not result in degradable or fully compressible microspheres, or require elaborate, time-consuming preparation. We used a simple one-step microfluidic method to fabricate imageable, degradable polyethylene glycol (PEG) microspheres of varying sizes with homogenous dispersion of barium sulfate-a biocompatible, high-radiopacity contrast agent. The imageability of the microspheres was characterized using optical microscopy and microcomputed tomography as a function of barium sulfate loading. Microspheres with 20%wt/vol barium sulfate had a mean CT attenuation value of 1,510 HU, similar to that of cortical bone, which should enable visualization with soft tissue. Compared with unloaded microspheres, barium sulfate-loaded ones saw an increase in gelation and degradation times and storage modulus and decrease in swelling. Imageable microspheres retained compressibility and were injectable via catheter. The developed radiopaque, degradable PEG microspheres have various potential uses for interventional radiologists and imaging laboratories.

En-face optical coherence tomography analysis of gold and silver nanoparticles in endodontic irrigating solutions: An in vitro study.

Optical coherence tomography (OCT) is a non-invasive, non-radioactive optical diagnostic method based on low-coherence interferometry, which achieves images with different orientation. In dentistry, its major advantage is represented by the localization and characterization of the smallest defects in hard dental tissues, dental materials and of the smallest details in dental anatomy (supplementary canals, recesses, isthmuses, or intra-radicular connections). The aim of the present in vitro study was to evaluate using c-scan en-face optical coherence tomography, the optical opacity, and the distribution inside the root canal lumen of several extracted human teeth of silver and gold nanoparticles from special irrigating solutions used in endodontic treatment. Twelve root canals from 5 human teeth were instrumented using the ProTaper Universal system after initial negotiation with hand K-files ISO no. 10 and rotary nickel-titanium PathFile instruments. An initial c-scan OCT analysis was performed for each sample to confirm that the root canal lumen was empty from radiopaque materials (Group 1). Teeth were first irrigated with NanoCare Plus (Group 2) and then with NanoCare Gold (Group 3) and C-scans were repeated after each irrigation method. The OCT investigation started at the tooth apex, at a depth of 1 mm from its tip. Subsequently, 100 slices of 10 microns were obtained from each root canal. Images were captured and then analyzed with ImageJ software to calculate the level of grey inside the root canal lumen. The highest values of grey were obtained in the samples irrigated with NanoCare Gold after NanoCare Plus (Group 3). The present study proved that both nanoparticles inserted in root canal irrigants were evidenced through OCT imagistic analysis due to their optical opacity, which allowed their highlighting in an empty root canal lumen, after the endodontic treatment was performed and the root canal was cleaned and shaped using specific protocols.

Post-pregnancy recurrent biliary colic with intraoperative diagnosis of limy bile syndrome.

IntroductionLimy bile syndrome (LBS) is an unusual condition in which gallbladder and/or bile ducts are filled with paste-like radiopaque material with a high calcium carbonate content. It can be rarely associated with PTH disorder and hypercalcemia.Presentation of caseA 35-year-old woman presented with epigastric and right hypochondrium pain since a few hours. Similar attacks occurred in the past months soon after a pregnancy with vaginal delivery. Laboratory findings were not significant. The abdominal ultrasound highlighted a micro-lithiasis of gallbladder without complications. Considering the recurrent biliary attacks, laparoscopic cholecystectomy was performed with intraoperative diagnosis of LBS. A subsequent endocrinological screening highlighted a normocalcemic hyperparathyroidism associated with Vitamin D deficiency, likely related to the recent pregnancy and not to LBS.DiscussionLBS is a rare condition with not clear etiology, frequently associated with cholelithiasis, of which it shares clinical presentation and potential complications. Diagnosis of LBS is based on abdominal X-ray/computed tomography scan, or it could be an intraoperative finding. The gold standard treatment is represented by laparoscopic cholecystectomy. The pregnancy with its related cholestatic phenotype could facilitate the LBS manifestation. An endocrinological screening should be performed to rule out a concomitant calcium metabolism disorder.ConclusionKnowledge of this rare condition could help general surgeons handle it properly.

A Radiolucent Electromagnetic Tracking System for Use with Intraoperative X-ray Imaging.

In recent times, the use of electromagnetic tracking for navigation in surgery has quickly become a vital tool in minimally invasive surgery. In many procedures, electromagnetic tracking is used in tandem with X-ray technology to track a variety of tools and instruments. Most commercially available EM tracking systems can cause X-ray artifacts and attenuation due to their construction and the metals that form them. In this work, we provide a novel solution to this problem by creating a new radiolucent electromagnetic navigation system that has minimal impact on -ray imaging systems. This is a continuation of our previous work where we showed the development of the Anser open-source electromagnetic tracking system. Typical electromagnetic tracking systems operate by generating low frequency magnetic fields from coils that are located near the patient. These coils are typically made from copper, steel, and other dense radiopaque materials. In this work, we explore the use of low density aluminum to create these coils and we demonstrate that the effect on X-ray images is significantly reduced as a result of these novel changes in the materials used. The resulting field generator is shown to give at least a 60% reduction in the X-ray attenuation in comparison to our earlier designs. We verify that the system accuracy of approximately 1.5 mm RMS error is maintained with this change in design.

Image in medicine: Cement pulmonary embolism

A 65-year-old woman was treated for vertebroplasty (cement injection). 24 hours after the procedure, she complains chest pain. A CT scan was performed which revealed on the same image section the presence of highly radiopaque material in a right basal segmental artery the density of which is strictly identical to that of the cement of the treated vertebra (yellow arrows). This cement pulmonary embolism canot be disolved by an anticoagulant treatment.

Clinching in In-situ CT – Experimental Study on Suitable Tool Materials

In lightweight design, clinching is a cost-efficient solution as the joint is created through localized cold-forming of the joining parts. A clinch point’s quality is usually assessed using ex-situ destructive testing methods. These, however, are unable to detect phenomena immediately during the joining process. For instance, elastic deformations reverse and cracks close after unloading. In-situ methods such as the force-displacement evaluation are used to control a clinching process, though deviations in the clinch point geometry cannot be derived with this method. To overcome these limitations, the clinching process can be investigated using in-situ computed tomography (in-situ CT). However, a clinching tool made of steel would cause strong artefacts and a high attenuation in the CT measurement, reducing the significance of this method. Additionally, when joining parts of the same material, the sheet-sheet interface is hardly detectable. This work aims at identifying, firstly, tool materials that allow artefact-reduced CT measurements during clinching, and, secondly, radiopaque materials that can be applied between the joining parts to enhance the detectability of the sheet-sheet interface. Therefore, both CT-suitable tool materials and radiopaque materials are selected and experimentally investigated. In the clinching process, two aluminium sheets with radiopaque material in between are clinched in a single-step (rotationally symmetric joint without cut section). It is shown that e.g. silicon nitride is suited as tool material and a tin layer is suitable to enhance the detectability of the sheet-sheet interface.

Pen cap in the urinary bladder: A rare type foreign body in the urinary bladder in a 16 years old female

Foreign body in the urinary bladder is a rare urological presentation and in most cases are due to self-insertion usually for autoerotic stimulation. We presented a case of 16 years old female who presented with history recurrent urinary tract infection for 6 months. After thoroughly work up she was diagnosed to have a pen cap in her urinary bladder. The foreign body in the urinary bladder was detected by abdominal ultrasound, Kidney, Ureter and Bladder (KUB) X-ray did not detect any abnormal radiopaque material in the area of the urinary bladder or upper tract. At cystoscopy, one pen cap was identified and removed successful.

Bone Temperature Variation Using a 3D-Printed Surgical Guide with Internal Irrigation

Bone overheating is a possible cause of implants early failure. When a surgical guide is used, the risk of heat injury is greater due to the reduced efficacy of the irrigation. The aim of this ex vivo study was to evaluate the effect of an additional built-in irrigation on bone temperature variation during implant osteotomy. Twelve bovine ribs were used. Cone beam computerized tomography (CBCT) was performed and a 3D-printed surgical guide with additional built-in irrigation tubes was produced for each rib. A total of 48 osteotomies were prepared, to compare the supplementary internal irrigation system (Group A) with external irrigation alone (Group B), no irrigation (Group C) and with free-hand surgery with external irrigation (Group D). Temperature was measured by three thermocouples placed at depths of 1.5, 7, and 12 mm. The largest temperature variation at each thermocouple showed median values of 3.0 °C, 1.9 °C, and 2.3 °C in Group 1; 2.3 °C, 1.7 °C, and 0.9 °C in Group 2; 3.2 °C, 1.6 °C, and 2.0 °C in Group 3; 2.0 °C, 2.0 °C, and 1.3 °C in Group 4, respectively. No differences were found among the four groups. In general, the highest temperature increase was observed with the use of the first drill (cortical perforator). Post-experimental CBCT revealed the presence of radiopaque material clogging the aperture of the internal irrigation channels. Additional internal irrigation was not found to significantly contribute to decrease bone temperature in this ex vivo setting.

Production and characterisation of new bioresorbable radiopaque Mg–Zn–Y alloy to improve X-ray visibility of polymeric scaffolds

For the medical diagnosis, radiopaque materials (RM) made from high specific gravity elements like Pt, Au, Ta, Iodine, Bromine are either attached or blended or coated on an implant to makes it detectable under X-ray/Fluoroscopy/CT-Scan. RM facilitate the surgeon in an operation theatre to position an implant during the surgery. Mainly, RM are non-degradable, thus in case of biodegradable implants, it may detach from the body and accumulate in vital organ cause serious health issue. Therefore, a new bioresorbable radiopaque material (BRM) was produced by alloying the high specific gravity elements Zn (35% w/w) and Y(4% w/w) with Mg metal. In this alloy, three main phases were identified, alpha Mg, Mg 7 Zn 3 and icosahedral quasicrystalline I-phase Mg 3 Zn 6 Y, which reinforce the Mg matrix. Hereafter, BRM was powdered to a size of less than 25microns and blended in different ratios with bioresorbable poly- l -lactic acid (PLLA) for fabricating PLLA/BRM bio-composite. BRM microparticles were uniformly distributed and interfacial bonded with the matrix. The X-ray was passed through bio-composite to capture µCT radiograph for evaluating linear attenuation co-efficient (µ) and optical density (OD). Thermal analysis reveals that BRM particles act as a nucleating site and enhance the crystallinity of the polymeric chain. During the In Vitro accelerated degradation study, the alkaline nature of BRM neutralise the acidity of PLLA and balance the pH of the body fluid to reduce the inflammatory reactions, but this compromises the stability of the polymer as it increases the decomposition rate.

Intrinsically radiopaque biomaterial assortments: a short review on the physical principles, X-ray imageability, and state-of-the-art developments.

X-ray attenuation ability, otherwise known as radiopacity of a material, could be indisputably tagged as the central and decisive parameter that produces contrast in an X-ray image. Radiopaque biomaterials are vital in the healthcare sector that helps clinicians to track them unambiguously during pre and post interventional radiological procedures. Medical imaging is one of the most powerful resources in the diagnostic sector that aids improved treatment outcomes for patients. Intrinsically radiopaque biomaterials enable themselves for visual targeting/positioning as well as to monitor their fate and further provide the radiologists with critical insights about the surgical site. Moreover, the emergence of advanced real-time imaging modalities is a boon to the contemporary healthcare systems that allow to perform minimally invasive surgical procedures and thereby reduce the healthcare costs and minimize patient trauma. X-ray based imaging is one such technologically upgraded diagnostic tool with many variants like digital X-ray, computed tomography, digital subtraction angiography, and fluoroscopy. In light of these facts, this review is aimed to briefly consolidate the physical principles of X-ray attenuation by a radiopaque material, measurement of radiopacity, classification of radiopaque biomaterials, and their recent advanced applications.

S1427 Lime-A-Way: Limy Bile Syndrome Complicated by Biliary Obstruction

INTRODUCTION: Limy bile syndrome (LBS), also known as milk of calcium bile, is a rare disorder of unclear etiology, characterized by the accumulation of thick, paste-like radiopaque calcium salts in the gallbladder and common bile duct (CBD). It is prevalent in 0.1% of patients that undergo cholecystectomies and can lead to life-threatening complications, necessitating early recognition. We report a case of this rare clinical entity presenting with obstructive jaundice and causing debilitating abdominal pain and chronic cholecystitis. CASE DESCRIPTION/METHODS: A 51-year-old man with no past medical history presented with 4 months of worsening sharp, post-prandial right upper quadrant abdominal pain and nausea. Vital signs were normal. Physical exam was notable for scleral icterus, jaundice, tenderness to palpation in the right upper quadrant of his abdomen and negative Murphy’s sign. Laboratory data was notable for AST 195 U/L, ALT 520 U/L, alkaline phosphatase 186 U/L, total bilirubin 6.2 mg/dL (conjugated 2.8/unconjugated 0.9). Abdominal ultrasound showed CBD dilation to 10 mm without gallstones. Abdominal CT showed a dilated CBD and densely hyperattenuating material along the inferior gallbladder wall and within the CBD (Figure 1). Given the absence of stones, the diagnosis of LBS was suspected. He underwent ERCP with sphincterotomy and copious amounts of thick paste-like sludge was swept from the duct, confirming the diagnosis of LBS (Figures 2, 3). His symptoms and biochemical abnormalities resolved rapidly following ERCP, and he underwent laparoscopic cholecystectomy with pathology confirming chronic cholecystitis. DISCUSSION: LBS is a rare disorder with poorly defined pathogenesis. Abnormalities in calcium metabolism, variable gallbladder pH and gallbladder stasis are factors that may cause calcium salt precipitation. Most patients present with biliary colic or cholecystitis. LBS can also present as incidental radiopaque shadows below the liver on abdominal x-rays in asymptomatic individuals. The identification of these calcifications should prompt further investigation with ultrasound and CT to distinguish LBS from other calcifying pathologies such as porcelain gallbladder in which gallbladder wall calcification is demonstrated as opposed to radiopaque material within the gallbladder itself. Timely recognition of this rare syndrome and early cholecystectomy is crucial as it can lead to complications such as biliary obstruction, cholangitis, biliary pancreatitis and cholecystitis.Figure 1.: CT showing hyperattenuating material along the inferior gallbladder wall.Figure 2.: EGD showing thick paste-like sludge.Figure 3.: ERCP images.

Measurements of the gingival papillae architecture using cone-beam computed tomography in young Chinese adults.

BackgroundThe aim of this study was to measure the morphology of interdental papillae (IP) in maxillary anterior teeth using cone-beam computed tomography (CBCT).MethodsTwenty-seven periodontally healthy subjects with 135 IP were evaluated by means of periodontal examination and a CBCT scan with an elastomeric matrix containing radiopaque material in position. According to the status of tooth contact and presence of IP, subjects were categorized into three groups: open contact point, complete papillae, and deficient papillae group. The papillae height (PH), facial-lingual thickness (FLT), and interdental distance (IDD) were measured. Data was analyzed with the significance level at α = 0.05.ResultsThe mean PH values were 4.17 ± 0.51 mm, 3.99 ± 0.61 mm, and 3.99 ± 0.62 mm, for the open contact group, complete papilla, and deficient papilla group, respectively. The PH values of the recorded sites among central incisors, lateral incisors, and canine were 4.13 ± 0.56 mm, 3.87 ± 0. 63 mm, and 4.07 ± 0.58 mm, respectively. No statistically significant differences of the PH values were determined between the above three tested groups as well as between the different sites (p > 0.05). The IDD values obtained from the complete papilla group were significantly lower than the other tested groups (p < 0.05).ConclusionThe contact point condition of upper anterior sextants may not influence the presence and dimension of the IP in periodontally healthy subjects.

Comparison of the Accuracy of Image Registration Methods for Merging Optical Scan and Radiographic Data in Edentulous Jaws.

The image registration of optical scans to radiographic images is essential for performing computer-guided implant surgery. This study aimed to evaluate the effect of different image matching conditions on the accuracy of image registration for computer-guided implant surgery in completely edentulous jaws. The optical scan image of a completely edentulous study model was registered to the respective cone-beam computed tomography data using three different image matching conditions: small point (SP), large point (LP), and entire surface (ES). For the SP and LP groups, gutta-percha markers (1.0 and 3.0 mm in diameter) were attached to a base template, and a radiopaque impression material was relined on the intaglio surface of template in the ES group. Image registration was performed by 20 operators in the images obtained from each group at an interval of 2 weeks (n = 20 in each group), and the registration accuracy was assessed by calculating the aligned position of the edentulous arch image. One-way analysis of variance with Tukey post hoc tests was used to compare the results among the groups (α = 0.05). The mean registration error was significantly larger in the SP group (0.52 ± 0.19 mm) than in the LP group (0.29 ± 0.08 mm) and ES group (0.27 ±0.06 mm) (F = 24.689, p < 0.001). No difference was found between the LP and ES groups. The image matching discrepancy was more homogeneously distributed on the arch in the ES group than in the other groups. The accuracy of image registration is affected by the size of the congruent area shown in the optical scan and radiographic images. The entire surface-based matching method is more accurate as compared to the small point-based matching method in the image registration for implant planning in full edentulous jaws.

Detection of Vascular Pathways of Oral Mucosa Influencing Soft- and Hard Tissue Surgeries by Latex Milk Injection.

In this methodological study, the purpose was to visualize the macroscopic vascular pathway of the oral mucosa. Corpses were injected and fixed with Thiel's solution for embalming to keep the natural color, fresh texture, and elasticity of the tissues. Latex milk injection is a technique used to stain blood vessels. A combination of Thiel's embalming method and latex milk injection allows surgeons to work on a raw specimen and identify the distribution and anastomosis of vessels macroscopically in the oral mucosa for flap/incision design in periodontal and maxillofacial surgeries. The latex milk contains radiopaque material that enables clinicians to visualize the pathway of the blood vessels radiographically. A step-by-step protocol is described for the correct adjustment of Thiel embalming and latex milk injection. The combined application of both methods allows the clinician to understand anatomical structures practically. As a result, proper incisions and flaps can be designed, which prevents neurovascular damage, intraoperative bleeding, and postoperative morbidity during patient surgery.