The purpose of this study was to evaluate the amount of released of silver and copper oxide nanoparticles when they were incorporated in heat cured acrylic resin denture, chemical cured soft liner, and cream type adhesive. Material and methods:A total number of 240 samples were prepared, 80 denture base samples, 80 liner, and 80 adhesives, and 10 samples from each material were free from nanoparticles that act as a control. The remaining samples were divided into two groups: (Group I) contained denture base, liner and adhesive samples modified with copper-oxide nanoparticles concentration by (0.1%, 0.3%, and 0.5%, 10 sample each), and (Group II) has the same number of samples but modified with same silver nanoparticles concentrations. The samples were placed in distilled water for one week and the amount of release was measured by spectrophotometer. The recordings data were analyzed using Two-way repeated measures Analysis of Variance (ANOVA) to compare between the three groups as well as to study the effect of time within each group. Bonferroni's post-hoc test was used for pair-wise comparisons. P< 0.05 was considered.Results: Release was higher in denture adhesive followed by denture liner and denture base respectively in the two groups. The amount of release increased with increasing nanoparticles concentration in denture base and adhesive but not in denture liner. There was no significant difference between Group I, and Group II. Conclusion:Nanoparticle release was affected by the type of prosthetic material, nanoparticle concentration, but not nanoparticles type.

Purpose: To evaluate the effect of incorporation of 0.1%, 0.3%, and 0.5% concentrations of titanium oxide, aluminum oxide, and silica nanoparticles in the heat-cured acrylic resin denture base on the peel bond strength to a silicone denture liner. Methods: A total number of 100 heat-cured acrylic resin samples were prepared and classified into a control group and three groups according to the type of nanoparticle. Each group was classified into three subgroups according to the concentration of the nanoparticle (n=10). A Silicone based-soft liner was added over the acrylic resin specimens, and the peel bond strength was measured using the peeling bond strength test at an angle of 90°. Statistical analysis was done using a Two-way ANOVA test for interactions between peel bond strength and the different nanoparticle materials and their concentrations. Results: Two-way ANOVA showed that the three nanoparticles and different concentrations did not affect the peel bond strength. Conclusion: The nanoparticles in this study were not effective in increasing peel bond strength at the studied concentrations.

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Aim: This clinical study was conducted to evaluate the bone height changes around implant in implant supported complete mandibular overdenture. Subjects and methods: Twelve completely edentulous patients were selected for this study controlled from any systemic or local disease that may contraindicate implant placement. History taking, extra and intraoral examination, and radiographic evaluation were done for each patient. Preoperative cone beam computerized tomography (CBCT) was done for each to determine bone height and width. Each patient received two implants in the interforaminal area of mandible, three months later lower denture was converted into mandibular overdenture by picking up the metal house into the denture. The Radiographic evaluation for the marginal bone loss was done using Digital panoramic X-ray film from the apex of the implant to most coronal points of bone attachment mesially and distally. The bone height was calculated by subtraction of it from original bone length, and the average length of both mesial and distal sites was calculated. All evaluations were done at the time of implant placement, three months, six months, twelve, eighteen and twenty-four months of implant placement. One-way ANOVA with post hoc turkey test was used for multiple time comparison. Results: Significant bone height occur for comparisons between any follow up times more than 6 months, except between 3 and 12 months follow up. Conclusion: Significant peri-implant bone height changes occur in mandibular implant supported overdentures that increases with time.

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