Are implants for life? Peri-implant soft and hard tissue stability
Unfortunately, implants are not for life. There is a high percentage of patients who experience implant loss and/or peri-implant infections. A systematic review published in 2012 found that 7.1% of implants were lost ten years after placement (Pjetursson et al. 2012). The speaker stated that a long-term clinical study by him and his group found that 4.3% of implants were lost, and implant loss seemed to be clustered in individuals (implant loss affected 10.3% of the patients). The overall survival rate after ten years was 95.7% (Roos-Jansåker et al. 2006).
“Unfortunately, implants are not for life.”
For the implants which do survive, a (highly varied) number have been reported to experience peri-implantitis (PI). A number of different figures have been reported in the literature:
- Atieh et al. 2013: 19% of patients experienced PI (10% of implants)
- Derks & Tomasi. 2015: 1–47% prevalence of PI, with a weighted mean prevalence of 22%
- Renvert et al. 2017: 14% PI prevalence, mostly confined to a few individuals
- Muñoz et al. 2018: 17% PI prevalence (with high heterogeneity), found in their recent meta-analysis
These variations between reported rates of PI may be due to differences in the defining criteria applied to PI and/or limitations within the studies. Despite the varying numbers reported in the literature, however, we can assume that around 15–20% of patients will experience peri-implantitis (especially smokers and periodontitis patients). From these studies, it can be concluded that implant loss and peri-implantitis tend to cluster within individuals.
How successful can PI treatment be? It is often hard to control the progression of infection; however, maintenance care can sometimes hinder/prevent progression. Sometimes, removal of the affected implant is the best option. An RCT analysing a resective approach aiming to reduce pocket depth was recently performed. The study found that only 45% of treated implants fulfilled the success criteria, although the authors noted that implants with a turned surface had a 79% success rate, and implants with a modified surface had only 34% (Carcuac et al. 2015).
“Sometimes, removal of the affected implant is the best option”
The regenerative approach for treating PI was also studied in a recently published RCT. Patients with three- or four-wall intra-osseous defects were treated with flap surgery and decontamination, with or without augmentation with xenograft. The results of the study were highly significant and favoured the use of biomaterials (Renvert et al. 2018).
To increase the longevity of implants, the speaker outlined his recommendations:
- periodontitis must be treated before implants are placed
- a smoking cessation programme should be offered to patients who smoke
- individuals with poor metabolic control and/or cardiovascular disease should be considered as ‘risk patients’
- prostheses must be designed with suitable accessibility for oral hygiene
- screw-retained prostheses should be used to facilitate maintenance
- the frequency of maintenance therapy should be decided on an individual basis