Implant therapy is a commonly based method of replacing missing teeth. A range of physical, chemical, and biological modifications have been applied to the surface of titanium implants to improve their biological performance and osseointegration outcomes. Implant surface characteristics play an important function in several peri-implant cellular and molecular mechanisms. Clinicians are commonly placing dental implants with various surface roughness and modifications including plasma-sprayed, acid-etched, blasted, oxidized, hydroxyapatite-coated, or combinations of these procedures. Surface modifications are to facilitate early osseointegration and to ensure a long-term bone-to-implant contact without substantial marginal bone loss can be accomplished. It is apparent that different modifications have a range of beneficial effects, it is essential to consider at what time point and in what conditions these effects occur. This article reviews existing surface modification technologies of mainstream dental implants and the correlation between implant surface coatings and their performance of osseointegration or anti-bacterial ability it needs to be evaluated.
Objective: To evaluate the potential use of digital and reconstructed three-dimensional printed models as an alternative to conventional plaster models by assessing the accuracy of their linear measurements.
Methodology: Pre-treatment plaster models of 45 patients were selected from the archives of the Department of Orthodontics. Each physical plaster model was scanned and digitized using a three-dimensional (3D) laser surface scanning system (inEOS X5, Dentsply Sirona, Bensheim, Germany). The scanned STL files were later used to reconstruct models by 3D printing using Figure4® standalone 3D printer (3D systems, Rock Hill, South Carolina). Measurements of teeth 11 and 16, the transverse width of the upper jaw between the first molars (MM – intermolar width) and canines (CC – intercanine width) were done manually using a digital vernier caliper (Mitutoyo, Kawasaki, Japan), and the CAD Assistant software (Open cascade, Guyancourt, France). Intra examiner data, Intraobserver variability, and measurement accuracy were evaluated using Intraclass Correlation Coefficient (ICC) analysis was done using SPSS 20.0.
Results: The intraclass correlation coefficients were >0.8 indicating high reproducibility and reliability. Significant differences were found between the physical and the digital models but to a small proportion which were deemed not clinically relevant.
Conclusion: Both the digital models and reconstructed three-dimensional printed models using Figure4® technology were clinically permissible in terms of accuracy and reproducibility. The digital storage, transmission, and treatment planning in an environmentally friendly manner should promote digital over conventional records.
Introduction: Pheochromocytomas are catecholamine-secreting tumors arising from the chromaffin cells of the adrenal medulla. We describe an unusual case of pheochromocytoma located in the infrarenal area and associated with bilateral adrenal hyperplasia.
Case presentation: A 70-year-old patient was admitted for syncope, diaphoresis, and high blood pressure. Computed tomography showed a 73x70x72 mm retroperitoneal mass of the left infrarenal area. High levels of metanephrine and noradrenaline were found in the urine. A tumor resection was performed. A few days after surgery, the blood pressure suddenly decreased and could not be restored, resulting in the death of the patient. Histopathological examination of the surgical specimen revealed a proliferation of monotonous cells, with eosinophilic cytoplasm, round nuclei with prominent nucleoli arranged in clusters, and capsular and vascular invasion. The tumor cells expressed synaptophysin and chromogranin, without positivity for inhibin A or S100 protein. At the autopsy, both adrenal glands showed hyperplasia but unrelated to the tumor mass. The histological aspect, location, and immunophenotype indicated an ectopic infrarenal pheochromocytoma.
Conclusions: In patients with pheochromocytoma developed on ectopic adrenal tissue, clinical management might be difficult, and diagnosis can be sometimes established only based on post-mortem histopathological examination. Autopsy can be extremely useful in such cases with unexplained evolution.