Extra-oral assessment of conventional and CAD-CAM complete denture appearance by dental professionals and CRDP wearers: A randomized survey.

INTRODUCTION: Complete removable dental prostheses' (CRDPs) appearance may vary between conventional and contemporary CAD-CAM manufacturing techniques. OBJECTIVES: The aim of this randomized survey was to analyze appreciation of CRDPs, manufactured with different techniques, by dental professionals and elder CRDP wearers. METHODS: Four participant groups, comprised of undergraduate students (n=10), postgraduate residents (n=10), dental technicians (n=10) and elder CRDP wearers (n=10), evaluated the appearance of maxillary CRDPs manufactured by six different techniques: three conventional methods 1. flask-pack-press (FP), 2. Injection-molded (IM), 3. intrinsically colored natural gingiva finish before injection-molded (NG) and three CAD-CAM methods 4. milled base with bonded prefabricated teeth (M), 5. fully milled including milled teeth (FM) and 6. rapid-prototyped including printed teeth (P). A randomized, blinded survey included 18 pairwise comparative assessments and 12 individual judgements of the CRDPs on general appearance as well as pink and white aspects. Statistical analyses included parametric- and nonparametric tests as well as linear regression models; the level of statistical significance was set at p<.05. RESULTS: NG was preferred by the professional groups but not by the elder CRDP wearers (p<.05). P was scored lowest by all four participant groups (p<.05). CRDP wearers' ratings were less severe and within a narrower range. The ratings of the two CAD-CAM milled CRDPs (M and FM) were ranked closer to FP and IM); the order of preference was different depending on the participant groups. CONCLUSIONS: The findings of this study revealed marked differences in the assessment of CRDP appearances between dental professionals and older CRDP wearers. CLINICAL SIGNIFICANCE: A shared and informed approach to decision making concerning the CRDP appearance might foster denture acceptance and treatment success.

Histomorphological assessment of isolated abdominal organs after targeted perfusion with the contrast agent Angiofil® in postmortem computed tomography angiography.

The current literature about histological alterations and artefacts associated with postmortem computed tomography angiography (PMCTA) is scarce and limited to qualitative research. The aim of this study was to describe and quantify histological alterations and artefacts in histologic specimens of the inner organs. The spleen, the liver, the kidneys and the pancreas were eviscerated in the course of standard forensic autopsy, followed by manual arterial and venous perfusion of the organs with the lipophilic contrast agent Angiofil®. Computed tomography (CT) of the organ packages was executed to evaluate if the perfusion with Angiofil® was sufficient. The CT scans revealed a good delineation of the vessel trees up to the organ periphery, suggesting a sufficient perfusion. Tissue samples were taken before and after perfusion, stained with hematoxylin-eosin (H&E) and examined by using microscopy. Native and perfused specimens were assessed on the basis of a qualitative rating scale in regard to the integrity of the cells, the tissue architecture and induced alterations. Subsequently the observed differences before and after perfusion with Angiofil® were analyzed quantitatively. While the liver, spleen and kidneys could be evaluated, further microscopic examinations of the pancreatic tissue were not possible due to vast autolytic changes. On the cellular level no changes in the liver, spleen and kidneys were observed after administering Angiofil®. While the tissue architecture of these organs remained intact, a significant blood volume displacement occurred. As a consequence, tissue with hypoemic or normal blood state demonstrated congestion. Further, optically empty spaces emerged regularly in the vessels and the parenchyma of each organ as a surrogate for the lipophilic contrast agent. With a few exceptions an adequate perfusion up to the microscopic level was observed. Following the results of this investigation, CT-controlled manual injection of Angiofil® into isolated organs may be an alternative to the generalized in situ application of contrast agents in the course of PMCTA. It is of eminent importance to know the artefacts induced by an Angiofil® injection in order to avoid a misinterpretation or a masking of findings. Thus, a collection of native tissue specimens has to be done before contrast agent application.