Effect of the Mucosal Thickness on the Stress Distribution of Implant Retained Mandibular Over-Denture with Resilient Telescopic Attachment (in Vitro Study)

الملخص

The aim of this study was to evaluate the effect of mucosal thickness on stress distribution around implant retained
mandibular over-denture with resilient telescopic attachment. This in-vitro study was done on a three standard
educational edentulous mandibular model. According to the mucosal thickness divided into three groups, each
group had one standard model with two implants. Two implants were placed in the canine region. Tapered telescopic
attachment with occlusal convergence of 0.03 mm was attached to each implant fixture. For each group three different
mucosal thicknesses were used which are (one, two, three-mm respectively) layer of poly ethylene vacuumed sheet
was placed on the models to acts as a spacer and replaced with polyvinyl siloxane impression material to simulate
the resilient edentulous ridge mucosa. An experimental acrylic resin denture was conventionally fabricated on the
model. Four strain gauges were attached to each implant to measure the strain on the implants. By using universal
testing machine unilateral load applied to the occlusal surface of the right first molar region. The micro strain was
measured at the four sides of the implant (mesial, distal, buccal and lingual) at loading and non-loading sides. The
data was collected and statistically analyzed by two-way ANOVA.
The results of this study showed greatest strain with 1 mm mucosal thickness at different sites measurement
(lingual= 63.12) in loading side and with 2 mm mucosal thickness (Lingual= -9.37) in the non-loading side and
the greatest strain with 3 mm mucosal thickness at different sites measurement (mesial= 5.62) in the loading side.
The stress was lowest with 3 mm mucosal thickness in the mesial and distal sides. For all sites for loading side was
associated with greater strain then non loading side for all the groups.
The peri-implant stress reduced as the thickness of the mucosa covered the residual ridge increase, when resilient
telescopic attachment is used with implant supported over-denture.