Alternative Method to Evaluate the Adaptation of Implant-Supported Multi-Unit Prosthetic Frameworks.
Various methods to evaluate the adaptation of dental prostheses are available; however, only a few of these methods assess the adaptation of the framework as a whole. This study aimed to propose an alternative method to evaluate the adaptation of implant-supported multi-unit Co-Cr alloy frameworks.MATERIALS AND METHODS
A four-unit framework supported by two implants was designed using a computer. Six dots with a diameter of 0.2 mm were designed randomly using 3Shape software on the abutment surface of the framework for measurement. Then, Co-Cr frameworks were fabricated via the milled and selective laser melting (SLM) techniques (n = 10 for each technique). They were subsequently scanned and exported as files in stereolithography format. The distances between two dots roughly along 3D directions were measured in both the designed framework and fabricated frameworks. The differences in distances were calculated. The adaptation of the frameworks was also evaluated using the impression replica method. The data were compared and statistically analyzed via t-test.RESULTS
The average difference of the distances between the designed and milled frameworks was 0.046 ± 0.057 mm when evaluated using the new method. This result was significantly different from that between the designed and SLM frameworks (0.073 ± 0.048 mm, p < 0.05). The average marginal gap width of the milled frameworks was 44.44 ± 8.61 μm when evaluated using the impression replica method. This result was also significantly different from that of the SLM frameworks (57.31 ± 7.97 μm, p < 0.05).CONCLUSIONS
The new method can evaluate the adaptation of implant-supported multi-unit frameworks, thereby making assessments more effective and comprehensive when it is combined with the traditional impression replica technique.