Purpose: To evaluate the effect of extracoronal attachment retainer unit with and without incorporation of lingual bracing arm on vertical alveolar bone height changes of abutment teeth in mandibular distal extension removable partial dentures.
Materials and Methods: Eight patients were chosen for this study with maxillary completely edentulous arch opposed to mandibular distal extension ridges posterior to second premolar teeth. The patients were randomly and equally divided into two groups; (group I) received extracoronal attachment removable partial dentures with lingual bracing arm incorporated in the retainer unit and (group II) received extracoronal attachment removable partial dentures without lingual bracing arm. For each group, the abutment vertical alveolar bone height changes were evaluated radiographically at time, after 6 and after 12 months of RPD insertion.
Results:
No significant difference was noticed when comparing group I&II regarding crestal alveolar bone resorption along interval periods of the study.
Conclusion: lingual stabilizing arm is not obligatory for augmentation of bracing in extracoronal attachment distal extension RPD when abutment teeth have available occlusoginigival height.