Dental Implants prone to fracture

1
2039
Dental implants
Let’s hope it works.

Keren Shemtov-Yona, DDS, a dental researcher at the Technion-Israel Institute of Technology, has examined 100 discarded dental implants under a scanning electron microscope, and found that more than 60 per cent of the implants had cracks and other flaws.

In an article in the latest Journal of the Mechanical Behavior of Biomedical Materials, she has warned about the high rate of flaws in dental implants and their potential for fracturing.

She is not the first researcher from The Technion-Israel Institute of Technology to come to this conclusion. Two years ago, Dr Liran Levin, an assistant professor of periodontology at the Institute, reviewed 19 published studies that looked at either implant survival rates or tooth survival rates over at least 15 years. He found that about 4 per cent to 13 per cent of teeth not implanted were lost. None to 33 per cent of implants were lost. According to the U.S. National Institutes of Health, an implant is viewed as successful if it is functional for five years in 75 per cent of cases.

“This is one of the first reviews comparing the long-term survival of dental implants as opposed to properly treated and maintained teeth,” Dr Levin said at the time.

The reason, implants fail, Dr Levin suggested, is that far from preventing bone loss, implants may promote it by triggering a serious infection, different from normal gum disease, which slowly destroys the bone holding the implant in place, causing it to loosen.

“We’ve got a new man-made disease, peri-implantitis,” he told newspapers at the time.

Following this latest study, Dr Shemtev-Yona also wants to encourage dental implant manufacturers and dentists to find ways to reduce “metal fatigue” – the localized structural damage that occurs when a metal is subjected to repeated applied loads. Over time, metal fatigue causes many of the implant-related fractures.

“Extracting and replacing a broken dental implant is a complex surgical procedure,” she said. “The time has come for both the dental community and manufacturers to come to avoid unnecessary surgical procedures.”

The implants in the study were extracted from wearers not because they were broken, but because of progressive bone loss around the titanium post that anchors them in place. All appeared to be in perfect condition prior to analysis. However, upon inspection using x-ray and scanning electron microscopy, mechanical defects were revealed in 62 per cent of the implants.

“The implants were a random combination of two materials, titanium alloy (Ti-6Al-4v) and commercially pure titanium (CP-Ti),” explained Dr Shemtov-Yona. “The CP-Ti implants had more cracks than the titanium alloy.”

“Embedded particles appear to be linked to the generation of surface defects that evolve into full cracks,” she pointed out. The effect of time and the wear and tear of daily use may also contribute the potential for manufacturing flaws to develop into cracks and subsequently lead to the ultimate failure of the materials of which they are made.

“Also, every individual has both different chewing habits and oral environment. Mastication can cause a repeated loading, leading to degradation of the implant materials and metal fatigue,” she explained.

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1 COMMENT

  1. I wonder if certain manufacturers are immune to the same faults in this Study.
    Are their certain makers of implants that have a ideal/better surface.
    May have to dig out the paper to see if the study has the names of these ‘defective implants’.

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