Digital occlusal analysis of pre and post single posterior implant restoration delivery: A pilot study

Abstract

Objectives: The purposes of this study were to analyze the effects of single posterior implant restorations delivery on the redistribution of bite force and to evaluate the changes in occlusal force distribution of prostheses and potential influencing factors on occlusion variation at different stages.

Materials and methods: Thirty-two single posterior restorations in 30 participants (18 women and 12 men aged 27 to 75 years) were placed into either a unilateral single-tooth defect (n = 17) or on either side of a bilateral teeth defects (n = 15). The bite force (%) of the prostheses, teeth and segments at the maximum intercuspation position (MIP) was evaluated using a T-scan at 5 stages (pre-placement, immediately following placement, and 2 weeks, 3 months, and 6 months post-placement).

Results: The occlusal force of implant-supported prostheses was significantly (P = .000) lower than those of the control natural teeth at the baseline, then no significant difference was found with that of the mesial teeth at 3 months, and finally it was significantly (P = .000) lower than that of the distal teeth at 6 months; meanwhile, it significantly (P = .008) increased by a mean of 2.04 times from 2 weeks (3.39 ± 2.61%) to 3 months (6.90 ± 4.77%), whereas no significant difference (P = .900) was found from 3 months (6.90 ± 4.77%) to 6 months (7.31 ± 4.60%). In addition, the bite force of the posterior segment on the restored side of both unilateral and bilateral gaps was significantly (P = .013,.001) improved by 3.31% and 6.83%, respectively, although the discrepancy in bite force significantly (P = .039) increased from an initial 3.52% to 5.02% for subjects with bilateral defects, accompanying increases in the proportion (15.38%) of the level III bilateral bite force deviation (P >.05).

Conclusions: Bite force and masticatory ability can be improved with the immediate delivery of a single posterior implant restoration. The bite force distributed on the implant prosthesis inevitably increases after placement of implant prostheses, a routine follow-up and occlusal evaluation are strongly needed.

Fig 1. Research flow chart.

Fig 2. Percentage and proportion of the bite force between contralateral same teeth and implant restorations (immediately following crown insertion).

Fig 3. High density of the bite force on implant crown (16) from T-scan (inserted immediately).

Red arrows indicate 2D and 3D images of the high density of occlusal contact.

Fig 4. Changes in the average bilateral bite force (before treatment vs immediately following restoration).

Fig 5. T-scan images of the occlusal force distribution before and after placement of restoration.

Red arrows reflect the center of bite force (red and white diamond icon). (A) Unilateral one missing: pre- 46 implant restoration insertion; (B) Unilateral one missing: post- 46 implant restoration immediate insertion; (C) Bilateral missing: pre- 36 implant restoration insertion; (D) Bilateral missing: post- 36 implant restoration immediate insertion.

Fig 6. Changes in the bilateral force deviation (before treatment vs immediately following restoration).

Fig 7. Comparison of the bite force distributed on implant restorations and teeth at different stages.

Fig 8. Changes in the average bite force distributed on the teeth and implant crowns over time.

Fig 9. T-scan images of the bite force distribution on implant and teeth in different stages.

(A) Post- 46 immediate insertion; (B) 2 weeks (final torque); (C) 3 months; (D) 6 months.

Fig 10. Diagram of the stepwise regression model of force changes at 3 and 6 months.

(A)ΔChanges in force (T1-T2): the amounts of changes in bite force of implant between 2 weeks and 3 months; (B)ΔChanges in force (T1-T3): the amounts of changes in bite force of implant between 2 weeks and 6 months.