Purpose: The occlusal force and occlusal contact area may be used to evaluate oral function following restoration of a missing tooth. This study aimed to monitor the initial changes in these factors after single molar implant restoration.

Materials and methods: Patients who underwent single implant restoration between December 2018 and September 2019 were recruited for this study. Occlusal force was measured before, immediately after, and 1 month after prosthesis placement. The occlusal contact area was evaluated immediately and 1 month after the placement. Data were grouped by sex, restored tooth, and restored side for analysis.

Results: In most groups, occlusal force was significantly increased 1 month after the placement compared with that before placement (P < .05), and the change was more significant in the first molar group than in the second molar group. There was a significant difference in the occlusal contact area of the implant prosthesis immediately and 1 month after placement when a thickness of 9 μm was used. The occlusal contact area of the natural tooth in the mesial side was significantly increased 1 month after placement (P < .05).

Conclusion: Occlusal force was significantly increased 1 month after implant restoration, and restoration of the first molar had the most significant effect on the occlusal force. Occlusal contact areas may differ according to the occlusal indicator used in the clinical setting because the changes were significant with only 0 to 9 μm.