Single-tooth implants may have a high long-term success rate, representing the favorability and overwhelming positive prognosis of the treatment, according to a comprehensive follow-up study.

“The study shows that the crowns were mostly replaced for aesthetic reasons rather than technical failures,” noted lead study author Sargon Barkarmo, PhD.

Introduced in the 1960s as a strategy to support dental prostheses in fully and partially edentulous patients, dental implants have since become the standard treatment option for missing teeth—particularly single-tooth gaps. Since their more widespread use in the 1980s, single-tooth dental implants have seen advancements in abutment and crown design, materials, and mechanical issues such as rotation of the abutment screw.

Because single-tooth gaps are common in younger patients, commonly as a result of trauma or aplasia, this population requires long-term success. This need necessitates long follow-up periods to address any dental implant complications and confirm treatment efficacy.

Published in Clinical Implant Dentistry and Related Research, researchers analyzed the outcomes as well as the biological and technical complications of single-tooth dental implants among 16 patients who underwent treatment at the Brånemark Clinic in Gothenburg in Sweden between 1982 and 1985. They noted that the patients had a total of 23 implants, and 13 of them were available for clinical and radiographic examinations in the follow-up study.

After a follow-up of 38 to 40 years, the researchers found that 95.6% of dental implants and 60.9% of implant-supported crowns survived. Further, they observed marginal bone level changes of 0.9 ± 1.0 mm (range = –0.5 to 3.0 mm), a mean plaque index of 16.9% ± 11.6% (range = 1%–34%), and a mean probing depth of 3.8 ± 2.2 mm (range = 0.0–7.0 mm).

Although mucositis was identified among the study participants, there were few biological and technical complications and no instances of peri-implantitis. Nonetheless, a proportion of the implant-supported crowns had been replaced during the follow-up period for aesthetic purposes.

“It is impressive that the single-[tooth] implants function so well after such a long time,” noted co–study author Jan Kowar, PhD, also of the University of Gothenburg. “[T]he results show that the implants remain in place and that the bone loss around them is virtually unchanged after 40 years,” he concluded.

No conflicts of interest were reported.