Functional Relining Versus Digital Altered Cast of Selective Pressure Impression Techniques Using Digitally Fabricated Distal Extension Frameworks: Peri-abutment Bone Height Changes (part 1)

Aim of the study: To estimate the impact of using two various impression techniques on peri-abutment bone height changes in mandibular Kennedy Class I partially edentulous patients using digitally fabricated distal extension frameworks (3D printed).Materials and Methods:A total of twenty patients with mandibular Kennedy Class I partially edentulous arches were involved in this study from the outpatient clinic at the Faculty of Dentistry, Mansoura University. Patients were rehabilitated with maxillary complete dentures and mandibular removable partial dentures fabricated on digitally constructed framework (3D printed) using two different impression techniques. Functional relining impression technique and digital altered cast of targeted pressure impression technique. Peri-abutment bone height changes were examined at insertion ,6months and 12 months after insertion employing cone beam CT.Results:There was a statistically insignificant difference in peri-abutment bone loss among functional relining group and digital altered cast group, these results suggest that both fabrication methods yielded similar amounts of peri-abutment bone loss over time. However, when examining the progression within each group, paired t-tests displayed a statistically significant rise in bone loss from T0 to T12 (p-values ≤0.05), indicating a progressive pattern of abutment bone resorption independent of the fabrication method.Conclusion: Considering the limitation of this research, it is evident that, when fabricating removable partial dentures with distal extension bases, the digital altered cast impression technique proves to be a promising approach, demonstrating similar outcomes to functional relining in preserving the alveolar bone surrounding abutment teeth.