RETENTION AND CHEWING EFFICIENCY OF TWO DIFFERENT DISTRIBUTIONS OF FOUR MINI-DENTAL IMPLANT IN MANDIBULAR IMPLANT RETAINED OVERDENTURES

Purpose: The purpose of this research was to study the effect of two different distribution of four mini-dental implant retaining mandibular overdenture on it’s retention and patient chewing efficiency.
Materials and methods: Twelve completely edentulous male patients were selected from department of Prosthodontics, Faculty of Dentistry; Suez Canal University. Patients received maxillary complete dentures opposing implant retained mandibular overdentures with four mini dental implant .The patients were randomly classified into two equal groups according to mini dental implant’s distribution. Group I : in which patients received four mini dental implants placed equally in the intrforaminal region. GroupΙΙ : in which patients received four mini dental implants, in the canine and the first molar regions in each side of the arch Clinical evaluation A-Mandibular overdenture retention . A- digital forcemeter device was used to measure mandibular overdenture retention. B- Chewing efficiency (Masticatory performance) Six chewing efficiency records were made for each patient as follows: 3 times periods at (one, two & three) months for the two types of (hard& soft) food The data obtained were reported in the form of mean values of both the chewing times and number of chewing strokes. Then chewing velocity (stroke/sec) were calculated. These data were recorded and statistically analyzed.
Results: The results of this study showed that there was increase in mean values of chewing efficiency of hard and soft food for both groups in favor to group II with non statistical significant difference between both groups except after three months in masticatory performance. Also there was increase in mean values of mandibular overdenture retention for both groups in favor to group II with highly statistical significant difference during all observation periods at (p≤0.01).
Conclusion: Within the limitations of this study, it may be concluded that wide distribution of immediately loaded mini-dental implants used in mandibular overdentures through posterior placement beyond the interforaminal area results in favorable response in terms of increased denture retention. This positively reflected on the patient comfort with increased his self confidence and psychological acceptance consequently, improves oral function and chewing efficiency.