Trueness and tissue surface adaptation assessment of digital versus conventional mandibular implant-assisted complete overdenture

Purpose Evaluation of trueness and tissue surface adaptation of digital versus conventional mandibular implant-assisted complete overdenture (IACO). Materials and methods Two implants were installed in the inter foraminal region of an epoxy resin model, which was scanned and saved as a Standard Tessellation Language (STL) file. The reference model with the implants was duplicated into 20-stone models. All models were scanned and the STL files were saved for digitally designed 20 IACOs. Half of them were fabricated by three-dimensional (3D) printing technology and considered as group I (the digital group). The other half were fabricated by the conventional pack and press technique and considered as group II (the conventional group). To evaluate the trueness, all IACOs were scanned and superimposed to the STL files of the original design by digital software. By using the same software, the gap between the intaglio surface of the scanned IACOs and the reference model was measured to evaluate the tissue surface adaptation. Results The statistical analysis by using t test revealed a highly significant difference between the two groups with less mean deviation value of the digital group with a P value less than 0.001. There is a significant difference between the two groups with P value of 0.035 at the implant region in the digital group. The overall adaptation between the two groups showed a significant difference with less mean deviation value of the digital group with a P value of 0.041. Conclusion The digital group has better trueness and adaptation than the conventional group. Despite the gap in the implant area in the digital group, the overall fit of the digital group is better. Clinical implications Three-dimensional printing technology can achieve an acceptable fit and good retention. Digital technology and implant dentistry provide great hope for complete edentulism, especially in those with a completely edentulous mandibular arch. Digital implant-assisted complete overdentures showed better fit than conventional ones.