Biological complications may result in higher abutment loss in tooth- and implant-supported fixed dental prostheses compared with technical complications.
With advances in the surface characteristics of fixed dental restorations, newer implants are typically considered more reliable than previous implants—with 5-year survival rates for metal-ceramic implant-supported fixed dental prostheses of over 98%. However, certain prostheses may be susceptible to hardware complications such as ceramic chipping, occlusal screw loosening, and loss of retention.
Tooth-supported prostheses may be indicated in patients with surgical procedure contraindications caused by medical health issues, pharmaceutical contraindications, and insufficient bone volume to perform implant-based procedures. Tooth- and implant-supported fixed dental prostheses offer aesthetic treatment alternatives over removable partial dentures following comprehensive periodontal treatment and come with heightened proprioception and masticatory function, maximum bite force, and food comminution. These prostheses often have long-term positive prognoses if patients adhere to the maintenance program.
In a study, published in Clinical Oral Implants Research, investigators clinically and radiographically reexamined the long-term survival and complication outcomes of fixed dental prostheses placed in 40 patients between 1978 and 2002. Reexaminations took place between August 2019 and September 2020. The investigators divided the 223 reconstructions into four groups: tooth-supported single crowns, implant-supported single crowns, tooth-supported fixed dental prostheses, and implant-supported fixed dental prostheses. They used Kaplan-Meier functions to model the likelihood of complications.
The investigators then observed the patients for technical and biological complications. Technical complications included chipping, loss of retention, ceramic and/or framework fracture, fracture of the implant, and fracture of the abutment screw. In contrast, biological complications included dental caries at the abutment teeth, periodontitis, peri-implantitis, and horizontal or vertical fracture of the abutment tooth.
After a follow-up of 25 years, they found that the survival rates were 84% (95% confidence interval [CI] = 77%–92%) for tooth-supported single crowns, 63% (95% CI = 51%–79%) for tooth-supported fixed dental prostheses, 87% (95% CI = 71%–100%) for implant-supported single crowns, and 64% (95% CI = 34%–100%) for implant-supported fixed dental prostheses.
The most prevalent biological complications included carious lesions (10.6%), periodontitis (7.9%), and peri-implantitis (6.8%). The investigators noted that 20.2% and 10.8% of the patients experienced chipping and loss of retention, the most prevalent technical complications.
No conflicts of interest were disclosed.
