El-Khamisy NE1, Habib AH2, El- Mekawy NE3, Emera RM 3
1BDS, MSD, Senior Teaching Assistant of Removable Prosthodontics, Faculty of Dentistry, Mansoura University, Egypt.
2BDS, MSD, PhD, Professor of Removable Prosthodontics, Faculty of Dentistry, Mansoura University, Egypt.
3BDS, MSD, PhD, Associate Professor of Removable Prosthodontics, Faculty of Dentistry, Mansoura Universiry, Egypt.
Abstract:
Objectives: Evaluation of Computer Aided Design/Computer Aided Manufacturing (CAD/CAM) versus traditional fabricated distal extension removable partial dentures (RPDs) regarding passivity, changing of the alveolar bone height (radiographically) and mobility of the abutment teeth.
Materials and methods: Within patient cross over study was carried out on six patients were selected for this study with maxillary complete edentulous arch against mandibular distal extension ridges posterior to first premolar teeth. Half of the patients were used metallic CAD-CAM RPDs for the first 12 months, and half of the patients were used removable partial dentures that was fabricated by conventional lost wax technique. In the second 12 months, after rest period of 2 months cross matching of the patients was done. Patients who had received metallic CAD-CAM RPDs were received metallic removable partial dentures that was fabricated by conventional technique and the patients who had received metallic removable partial dentures that was fabricated by conventional technique were received metallic CAD-CAM RPDs.
After manufacturing of each metallic frameworks and before delivery of the dentures to the patients, the passivity was evaluated. The abutment teeth alveolar bone height changes were evaluated radiographically immediately after insertion, after 6 and 12 months of denture insertion using Corel Draw 11 system. Abutment teeth mobility was evaluated using Periotest device immediately after insertion, 6 and 12 for each type of the manufactured dentures.
Results: Group I (conventionally fabricated RPDs) recorded significant higher gaps between RPD components and supporting tissue in mm and lower percentage of contact than Group II (CAD/CAM RPDs) at different sites of measurements. There was no significant difference between group I (Conventionally RPDs) and group II (CAD/CAM RPDs) at both observation times (6 and 12 months) regarding abutment teeth mobility. Abutment mobility after 12 months was significantly higher than mobility after 6 months for group I i.e mobility increased with advance of time for group I only. There was a significant difference in abutment crestal bone loss between groups at distal sites only (Mann Whitney test, p < .05); as group I recorded significant higher bone loss than group II at both observation times for distal sites only.
Conclusion:CAD/ CAM RPD frameworks recorded significantly higher fit than conventionally fabricated RPD frameworks. The lingual bar major connector showed significantly higher gap than other RPD framework components for both groups (Conventional and CAD-CAM). CAD/CAM RPDs showed insignificant abutment mobility and significant lower crestal bone loss than conventionally fabricated RPDs.