Effect of Height Differences on the Retention and Wear Behaviour of Ball Attachment System Over Mandibular Dual Implants

Abstract

Purpose of the study: To comparatively evaluate the effect of height differences on the retention and wear behaviour of ball attachment system over mandibular dual implants. Materials and methods: Two groups of twenty samples each containing polymerised master block of dual implant analogues at same height in Group 1 and dual implant analogues of different heights in Group 2 were fabricated along with ball abutments, nylon cap and metal housing. Qualitative analysis of samples for wear factor were carried out using stereomicroscope and quantitative analysis of retention force at baseline, 360, 720, 1080, 1440 insertion-removal cycles were determined using Universal testing machine. statistical analysis were carried out using independent ‘t’ test and paired sample ‘t’ test. Results: Group I test samples, the sample mean obtained at baseline, 360, 720,1080, and 1440 cycles were 24.73N, 23.49N, 22.46N, 21.07N, & 19.28N respectively. Group II test samples, the sample mean obtained at baseline, 360, 720,1080 & 1440 cycles were 27.13N 25.80N, 24.16N, 22.73N and 21.85N respectively. comparison of the mean retention force of the test samples at baseline, 360 (3 months), 720 (6 months), 1080 (9 months) and after 1440 (12months) insertion-removal cycles within Group 1 and Group II using Paired sample ‘t’-test was statistically significant at all levels. Conclusion: Retention force was found to be higher on dual implants placed at different heights in mandibular anterior region and is statistically significant and corroborated by the Lesser surface deformations of attachment system.