Moatz Aly Ahmed, Emad. M. Agamy, Ahmed. F. Shawky And Amr. I. Badr ,

ABSTRACT
Since Their Introduction, Implant-retained Overdentures Have Represented A Feasible, Economical, And Highly Successful Treatment Option For Completely Edentulous Patients. Different Attachment Systems Have Been Effectively Used To Retain These Implant Overdentures, And Each System Has Advantages And Disadvantages. The Purpose Of This Study Was To Compare The Retentive Capabilities Of The Retention Sil Material And The Conventional Attachment Housing Of Locator Or Ball And Socket In Two Implant Retained Mandibular Overdenture And The Effect Of 3 Years Of Simulated Insertion And Removal.

Materials and Methods: An Acrylic Model Resembling Edentulous Mandible And Overdenture Were Constructed. Two Parallel Implant Analogues Were Inserted In The Canine Region. Two Attachment Systems Were Used With Their Prefabricated Matrices (Dentium Locator Clear And Dentium Ball Clear) Were Used; The Prefabricated Nylon Caps Were Replaced With Retention Sil Material. All Samples Were Subjected To 3240 Cycles Of Insertion And Removal To Simulate 3 Years Of Clinical Usage. The Universal Testing Machine Was Used To Record The Retentive Capabilities Of Different Attachment Systems.

Results: One-way ANOVA Followed By Tukey Post Hoc Test Was Used To Compare Between More Than Two Groups In Non-related Samples. There Was A Significant Difference In The Retention Capacity (p ?0.05) That Showed Higher Retention For Prefabricated Attachment Cap Materials Over The Retention Sil Material Where The Locator Attachment Showed The Highest Retention Value Either With Prefabricated Caps Or With Retention Sil Material.

Conclusions: From The Result Of This Study, It Can Be Concluded That: The Retentive Forces Of Implant Overdenture Stud Attachments Are Different And Should Be Considered During Attachment Selection. Prefabricated Attachment Matrices Give Higher Retentive Force Than Custom Made Matrices.