Occlusal contact was significantly increased 3 months after implant rehabilitation when compared to stage one (prior to implant rehabilitation). We assumed the reason was that some participant’s occlusion was worn down because the material of provisional restoration was resin. To observe the adaptation of masticatory function after rehabilitation with an immediately loaded implant-supported prosthesis, we compared the data of four stages (before and after implant surgery) using four tests (occlusal contact, approximate maximum bite force, masticatory efficiency, and recognition of hardness threshold). The present method was simple and acceptable for use in a clinical patient setting, as the specimens had characteristics similar to typical sweets that contain glucose. In a previous study, the present method for masticatory efficiency was validated and found to be comparable to a sieve method [40].

In this study, we measured occlusal contact and maximum bite during a 3-month follow-up period in patients with implant-supported prostheses. Generally, maximum bite force was increased after 3 months, with a positive correlation to occlusal contact, in accordance with the literature [41].

We found no differences regarding the masticatory efficiency of the specimen among the different time periods, even when bite force and occlusal contact area were significantly increased. Although the present sample is small, masticatory performance seemed to be influenced by the motivation of the participants, with more improvement immediately after implant treatment. However, that is mere surmise.

In the present study, there were no differences regarding the recognition of hardness threshold among the hardness levels at each stage. Edentulous patients with implant-supported dentures showed improved tactile discrimination ability and motor function in contrast to patients with complete dentures [42, 43] However, it is important to compare these results with those from patients with implant-supported prostheses in both jaws, lacking any kind of periodontal feedback. Trulsson [13] reported that the periodontal ligament had the highest sensitivity to changes in tooth load at low forces (below 1 N for anterior teeth and 4 N for posterior teeth). In dentate people, this may help in modulating the jaw muscles, especially when dealing with a rapid force build up, in relation to hard food.