Comparing volumetric and biological aspects of 3D-printed interim restorations under various post-curing modes

Purpose@#This study aims to compare the volumetric change, degree of conversion (DOC), and cytotoxicity of 3D-printed restorations post-cured under three different conditions. Materials and Methods: 3D-printed interim restorations were post-cured under three different conditions and systems: 5 min, 30 min, and 24 h. Three-unit and six-unit fixed dental prostheses (n = 30 for each case) were printed; ten specimens from each group were post-cured and then scanned to compare their volumetric changes. Root-mean-squared (RMS) values of the data were acquired by superimposing the scanned files with original files.Thirty disk-shaped specimens were printed to evaluate the DOC ratio. Fourier transform infrared spectroscopy was used to compare the DOCs of 10 specimens from each group. Human gingival fibroblasts were used to measure the cell viability of every specimen (n = 7). The data from this experiment were employed for one-way analysis of variance and Tukey’s post-hoc comparisons. @*Results@#Differences between the three-unit restorations were statistically insignificant, regardless of the post-curing conditions. However, for the six-unit restorations, a high RMS value was acquired when the post-curing duration was 30 min. The average DOC was approximately 56 - 62%; the difference between each group was statistically insignificant. All the groups exhibited cell viability greater than 70%, rendering them clinically acceptable. @*Conclusion@#The post-curing conditions influenced the volume when the length of the restoration was increased. However, this deviation was found to be clinically acceptable. Additionally, postcuring did not significantly influence the DOC and cytotoxicity of the restorations.

Comparing volumetric and biological aspects of 3D-printed interim restorations under various post-curing modes

Purpose@#This study aims to compare the volumetric change, degree of conversion (DOC), and cytotoxicity of 3D-printed restorations post-cured under three different conditions. Materials and Methods: 3D-printed interim restorations were post-cured under three different conditions and systems: 5 min, 30 min, and 24 h. Three-unit and six-unit fixed dental prostheses (n = 30 for each case) were printed; ten specimens from each group were post-cured and then scanned to compare their volumetric changes. Root-mean-squared (RMS) values of the data were acquired by superimposing the scanned files with original files.Thirty disk-shaped specimens were printed to evaluate the DOC ratio. Fourier transform infrared spectroscopy was used to compare the DOCs of 10 specimens from each group. Human gingival fibroblasts were used to measure the cell viability of every specimen (n = 7). The data from this experiment were employed for one-way analysis of variance and Tukey’s post-hoc comparisons. @*Results@#Differences between the three-unit restorations were statistically insignificant, regardless of the post-curing conditions. However, for the six-unit restorations, a high RMS value was acquired when the post-curing duration was 30 min. The average DOC was approximately 56 - 62%; the difference between each group was statistically insignificant. All the groups exhibited cell viability greater than 70%, rendering them clinically acceptable. @*Conclusion@#The post-curing conditions influenced the volume when the length of the restoration was increased. However, this deviation was found to be clinically acceptable. Additionally, postcuring did not significantly influence the DOC and cytotoxicity of the restorations.

Fabrication of closed hollow obturator for hard palate defect patient undergone maxillectomy / 대한치과보철학회지

Maxillectomy is performed to remove the tumor in the palate, maxillary sinus, buccal mucosa or nasal cavity. The resection range depends on the size and the extent of the tumor and it affects speech production or cause nasal regurgitation during feeding. Obturator can occlude an opening such as an oro-nasal fistula and protect the defect area. Successful reconstrucion of the patient's oral cavity who have gone over the maxillectomy is a difficult task. The condition and number of teeth, the remaining support area, and the extent of the defect area have a great influence on manufacturing the obturator. If these factors are disadvantageous, the prognosis of the prosthesis is uncertain. The final obturator must have a sufficient retention in the patient's oral cavity and must not irritate the surrounding tissue and support area where the resection was performed.In this case, a 55 year old female went through the maxillectomy and the only 3 teeth remained. And the retention of the maxillary prosthesis seems to be poor. So that, we fabricated the closed hollow obturator which has reduced weight compared to the conventional obturator. Consequently the closed hollow obturator can give better sealing and the adaptation.

Full mouth rehabilitation on the patient with deep bite and posterior bite collapse using re-establishment of occlusal vertical dimension / 대한치과보철학회지

The loss of posterior support and the abnormal jaw relation can cause pathologic findings. If deep bite patients with multiple missing teeth, can not have the stable posterior contact, the mandible moves posteriorly, and consequently the overjet and overbite get worse. And when the mandibular irregular occlusal plane is corrected, it is easier to have the bilateral balanced occlusion with the maxilla. So the treatment goal is to give proper posetrior support and establish appropriate anterior guidance, and ultimately provide improved mastication and esthetics recovery. In this case, a 68 year old man, having deep bite without posterior support was evaluated by the vertical dimesion decision flow-chart. An available prosthetic height, anterior occlusal relation such as overjet, overbite and the esthetic part such as facial height and the cephalometric analysis are the factors to be considered.