Masticatory Efficiency of Thermoplastic Versus Conventional Acrylic Resin Mandibular Implant Overdenture With Bar/Clip Attachment

Abstract

Objectives: To evaluate the effects of different base materials of mandibular implant-supported overdenture with bar/clip attachment on masticatory efficiency. Materials and Methods: Twenty-four edentulous patients were selected to place two interforaminal mandibular implants with custom-made cast bars to retain overdentures made from two different base materials and divided into two groups: Group I was the patients with heat-cured acrylic resin overdentures, and Group II was the patients with thermoplastic base overdentures. Masticatory efficiency was tested using three food categories (carrots, bananas, and apples) and measured by four parameters. One-way analysis of variance (ANOVA) with a post hoc Tukey test was used at the chosen probability level p < 0.05. Results: Group II was more efficient than Group I with the carrots as the difference was statistically significant for two parameters: the number of chewing strokes until the mouth was free of food with p=0.018 and the number of swallows it takes for the mouth to be empty of food p ≤ 0.001. With apples, the significance was related to two parameters: how many chews there were before the first swallow p=0.053 and the number of swallows until the mouth was empty of food p ≤ 0.001. With bananas, the significance is related to two parameters, the number of swallows until the mouth was free of food with p ≤ 0.001 and the time in seconds until the mouth was free from food p=0.037. Conclusions: The overdentures made with the thermoplastic base material and supported with bar/clip attachments were more masticatory efficient than patients whose overdentures were made of the traditional acrylic resin. Trial Registration: This clinical study presentation has been registered and publicly figured at clinical trial.gov PRS for protocol registration and results system under ID NCT05877092 University and conducted following the CONSORT checklist.

Keywords: bar/clip attachment system; masticatory efficiency; thermoplastic overdenture.

Figure 1

X-ray showing two implants inserted within the interforaminal region of the patient's mandible.

Figure 2

A custom-made bar and clip on the cast to construct a metal cobalt–chromium bar and clip.

Figure 3

X-ray showing a customized cobalt–chromium metal bar and clip installed for the implants.

Figure 4

The mean values of the number of chewing cycles until the first swallow between the test groups.

Figure 5

Number of chewing strokes until the mouth is free from food.

Figure 6

Number of swallows until the mouth is free from food.

Figure 7

Time (in seconds) until the mouth is free from food.