Early loading after 1 and 6 weeks for two unsplinted implants retaining mandibular overdentures does not compromise periimplant soft tissue health and marginal bone levels.

Aim of the study: This study was carried out to evaluate the effect of using ultra suction system on mandibular complete denture retention and on the rate of growth of candida albicans. Material and methods: Ten completely edentulous patients participated in this study. Each patient recived two dentures a conventional mandibular denture (D1 denture) constructed using heat cured acrylic resin and an ultra suction retained denture (D2 denture) which was constructed using heat cured acrylic resin with ultra suction system added to it. Patients were left to function with each denture set for a period one week, one month, three months respectivly during which they were recalled to test denture retention and to make microbilogical examination. Retention test was conducted using universal testing machine after pulling the denture from it's geographic centre. The collected records were recorded, tabulated and statistically analyzed for each denture using the paired t test. Results: The mean retention value for (D1 denture) were 3.66 ±1.07, 3.02±0.82, 4.07± 0.84 , 3.97 ± 0.99 at the baseline and after one week .one month ,three months respectively while for (D2 denture)values were 8. 01±2.80 , 8.35± 2.53, 8.72±2.19, 7.11±1.70 at the baseline and after one week .one month ,three months respectively. Statistical analysis of these data revealed a significance increase in the retention after application of ultra suction system. The mean values for microbilogy test were calculated using Chi square test at the base line and after three months of wearing dentures and after statically analyzing the results, it showed that statistically non-significant difference between conventional (D1) and ultra-suction (D2) denture (P=0.1286>0.05).

Aim of the study: The aim of this study was to assess the strains transferred by zirconia and metal resin-bonded attachments (RBAs) to the maxillary distal extension removable partial denture (RPD) supporting structures and compare them with the strains generated by the extracoronal attachment with full veneer retainers. Materials and Methods: Three identical partially edentulous models that were created with a 3D printing technology. The virtual models for the retainers and the three attachments were designed using digital software. Model (1): Zirconia resin-bonded attachment (ZRBA). Model (2): Metal resin-bonded attachment (MRBA). Model (3): Extracoronal attachment with full veneer metal ceramic retainer (ECFV). Using 3D printing technology, the wax patterns for the three types of attachments were printed, and the retainers were constructed and cemented on their models. This was followed by the fabrication of attachment-retained removable partial dentures on the three printed models. Each RPD was subjected to a compressive static load of 100N using a universal testing machine. Then the strain values were recorded. Results: On bilateral loading, there were significant differences in the recorded strains at the three strain gauge locations between RBAs and ECFV. At the SG-3 location, there was no significant difference between the strains generated by ZRBA and MRBA. During unilateral loading, the results revealed statistically significant differences between the three attachments at the loading and non-loading sides. Conclusion: With the limitations of this study, it can be concluded that, in distal extension maxillary RPD, there is no significant difference between the strains generated by zirconia and metal resin bonded attachments. While the extracoronal attachment with full veneer retainers applied less strains on RPD supporting structures than resin bonded attachments.

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Purpose:The purpose was to compare the clinical, radiographic, and prosthetic results of an All-On-Four maxillary hybrid prosthesis and a bar-clip retained maxillary overdenture after one year of follow-up in patients with mandibular hybrid prostheses. Materials and methods: Twelve participants with completely edentulous maxillae and mandibular hybrid prostheses were selected. Participants were randomly assigned to one of two groups: All-On-Four maxillary hybrid prosthesis group (HP) and bar-clip retained maxillary overdenture (BO) group. In the HP group, the patients received four maxillary implants in accordance with the All-On-Four concept. The implants were functionally loaded with maxillary fixed detachable hybrid prostheses. In the BO group, the patients received four parallel implants supporting bar-clip retained maxillary overdentures. Results: At 12 months, there were significant differences in gingival and plaque indices and probing depth between both groups for anteriorly placed implants. The plaque and gingival indices, and probing depth of the HP group were significantly greater than those of the BO group. For anterior implants, there was no difference in implant stability or marginal bone loss between the two prostheses. Group comparisons at the posteriorly placed implants revealed significant differences in plaque and gingival indices at 12 months. The total number of prosthetic complications required for the BO group was significantly higher than for the HP group. Conclusion: Within the limitations of this study, it was possible to conclude that, in patients with mandibular hybrid prostheses, both All-On-Four hybrid prostheses and bar-clip retained overdentures may be effectively utilized for rehabilitation of the edentulous maxilla using four implants since the clinical, radiological, and prosthetic outcomes were clinically acceptable and manageable. However, bar-clip retained overdentures may produce better clinical outcomes than All-On-Four hybrid prostheses, but they require more prosthetic maintenance.