Adaptation of Complete Denture Base Fabricated by Conventional, Milling, and 3-D Printing Techniques: An In Vitro Study.

AIM: The aim of this study was to compare the adaptation of complete denture base (CDB) manufactured by three different techniques: conventional, milling, and three-dimensional (3-D) printing. MATERIALS AND METHODS: A master cast was duplicated to create 60 gypsum casts. Twenty casts (n = 20) were attributed to each group. In the computer-aided design and computer-aided manufacturing (CAD/CAM) groups (milling and 3-D printing), the 40 gypsum casts reserved for these two groups were scanned. An STL file was obtained and a master CDB was designed and then fabricated according to each technique. In the conventional group, a polyvinyl siloxane putty mold was obtained from the milled CDB, and this mold was used to fabricate 20 conventional denture bases by compression molding using the silicon-gypsum technique in a bronze flask. The inner surfaces of the obtained 60 CDB were scanned and superimposed over their corresponding master cast. Deviation analyses were calculated using digital subtraction technique. Five functional areas (posterior palatal seal, anterior border seal, crest of the ridge, maxillary tuberosities, and palate) were selected to evaluate the variations in CBD adaptation. RESULTS: Based on the results and color maps of all selected regions, milling technique offers the best adaptation. The crest of ridge in the conventional technique showed the least adaptation and the posterior palatal seal in the 3-D printing technique showed the best adaptation. CONCLUSION: Within the limitations of this study, the CAD/CAM fabrication techniques seem to offer better adaptation of CDB compared to the conventional fabrication technique. Milled CDBs presented the most homogeneous distribution of adaptation, yet the 3-D printing process seems a promising techniques that needs to be addressed and perfected. CLINICAL SIGNIFICANCE: The CAD/CAM technologies can help overcome many limitations related to conventional impressions and therefore should be well investigated to improve the edentulous patient's quality of life.

Evaluation of the Adaptation of Complete Dentures Fabricated Using Intraoral Scanning and Conventional Techniques.

AIM AND OBJECTIVE: This study aimed to digitally analyze the 3-dimensional variations existing between conventional impressions and intraoral scans made in edentulous maxillae. MATERIALS AND METHODS: Ten (n = 10) edentulous maxillae of patients seeking a maxillary complete denture were scanned using an intraoral scanner. The same participants were subject to the conventional impression procedure for the fabrication of maxillary complete dentures. The dentures' intaglio surfaces were scanned and superimposed over their corresponding IOS files with a 2-base best-fit alignment. Deviation analyses were calculated using the digital subtraction technique. Four anatomical regions were preselected to evaluate the deviations at these sites (posterior palatal seal, anterior border seal, the crest of the ridge and palate). RESULTS: Based on the results and color maps of all selected regions, the overall difference between the two scans [IOS and denture intaglio surface scanning (DISS)] was not significant. The IOS technique allowed for predictable outcomes of treatment compared to those observed with conventional impression. The palatal area seems to be the region with the least deviation, while the highest incidence of discrepancy was reported in the anterior border seal. CONCLUSION: Within the limitations of this study, the IOS technique allowed the capturing of intraoral tissues and their immediate interpretation and transfer to a designing software making the impression procedure faster and easier. CLINICAL SIGNIFICANCE: The computer-aided design (CAD)/computer-aided manufacturing (CAM) technologies can help overcome many limitations related to conventional impressions and therefore should be well investigated to improve the edentulous patient's quality of life.

Anomalias del tracto urinario superior diagnosticadas por ultrasonido en pacientes con hipospadias / Anomalias of upper urinary tract diagnostic by echosonography in patient with hypospadias

Se estudio una muestra de 34 pacientes con edades comprendidas entre 0 y 13 años, afectos de hipospadias y que fueron atendidos en la consulta de Cirugía Infantil del Hospital Central Universitario "Antonio María Pineda" de Barquisimeto, de enero a diciembre de 1991. A todos se les realizó estudio ecosonográfico renal como examen de rutina, y se corroboraron los resultados patológicos encontrados con urografía de eliminación: 17 pacientes (50 por ciento) eran menores de 3 años; 20 pacientes (58,82 por ciento) presentaron hipospadias peneana, siendo la penana media la más frecuente con 10 casos (29,41 por ciento). Se detectaron anomalías del tracto urinario superior en 3 casos (8,82 por ciento), porcentaje considerado como alto (1,2,11). Las anomalías encontradas fueron: doble sistema pielocalicial izquierdo (1 caso), agenesia renal derecha (1 caso) y riñon pélvico izquierdo (1 caso). Dos de las anomalías detectadas (66,66 por ciento) se presentaron en pacientes afectos de hipospadias peneana media, y una (33,33 por ciento) se presentó en un paciente con hopospadias penoescrotal. Este estudio nos revela la importancia del estudio ecosonográfico renal en los pacientes afectos de hipospadia