Purpose: The objective of this study was radiographic assessment of the premolar teeth abutments alveolar bone resorption in mandibular Kennedy Class I removable partial denture (RPD) utilizing the broad stress distribution philosophy, either designed with multiple circlet clasp or compound Aker clasp.
Materials and methods: Twelve patients were enrolled for this study with upper completely edentulous arch against mandibular Kennedy Class I ridges posterior to the second premolar. The patients were divided into two groups according to the type of the clasp assembly design used, where the mandibular Kennedy Class I RPD was designed with multiple circlet clasp and compound Aker clasp assemblies for Groups I and II, respectively. The abutment alveolar bone resorption was evaluated radiographically after 1(st) 6, 2(nd) 6, and 12 months of mandibular Kennedy Class I RPD insertion.
Results: Second premolar abutment interdental alveolar bone resorption was significantly increased as compared to first premolar abutment along the interval periods of the study for Group I. The reverse was observed for Group II. Along the interval periods of the study, the alveolar bone resorption at the first premolar abutment of Group II was significantly increased compared to that of Group I while the reverse was observed when comparing the second premolar of Group I with that of Group II.
Conclusion: Compound Aker clasp is better than the multiple circlet clasp assembly as it reduces abutment alveolar bone resorption regards broad stress distribution philosophy is considered for distal extension cases.
Keywords: Broad stress distribution philosophy; changes of abutment alveolar bone height; mandibular Kennedy Class I.