Over the years I have noticed sometimes after placing and restoring implantsâespecially on lower posterior areasâthat the proximal contacts seemed to open up over time or have an area that allowed for food impaction.
After a recent post on Spear Talk, the discussion forum of Spear Education now available with a free Basic Membership, I found out that I wasnât the only one that has noticed this occurring over time. After reading the threadÂ and a few papers posted on the discussion forum, hereâs what I learned from two different articles:
- Somewhere between 34-43 percent, on average, of interproximal contacts will be lost between an implant supported fixed dental restoration and an adjacent tooth; the longer the period of observation (10 years) showed a higher rate (43 percent) of interproximal contact lost
- Fifty-two percent of the contacts are lost on Mesial vs. 16 percent on the Distal
- There are more contacts lost on the lower/mandibular arch (49.2 percent) vs. upper arch (31.8 percent)
There are a lot of thoughts or theories as to why this occurs including mesial drifting and interproximal wear over time leading to tooth movement and to the teeth drifting or shifting.
So how do we manage it going forward? Well, there are some thoughts on making some of the implant support restorations retrievable via screw-retention. This way when the contact opens up over time, the restoration can be removed; a proximal contact area is added back and then the restoration is placed back into position.
The bottom line is, when we do an implant support restoration we need to advise our patients that one of the long-term risks is shifting teeth and a space being created between the implant and adjacent tooth.
1. Byun S-J,Â Heo S-M,Â Ahn S-G,Â Chang M.Â Analysis of proximal contact loss between implant-supported fixed dental prostheses and adjacent teeth in relation to influential factors and effects. A cross-sectional study.Â Clin. Oral Impl. Res.Â 00,Â 2014;Â 1â6.,3,
2. Koori, Hidehiro; Morimoto, Keizo; Tsukiyama, Yoshihiro; Koyano, Kiyoshi. Statistical Analysis of the Diachronic Loss of Interproximal Contact Between Fixed Implant Prostheses and Adjacent Teeth. International Journal of Prosthodontics . 2010, Vol. 23 Issue 6, p535-540.
Jeff Lineberry, DDS, FAGD, Spear Visiting Faculty, Contributing Author. [ www.jefflineberrydds.com ]Â