Reports & Studies

Is implant maintenance important?

Monika Riedl

Dental implants require the same maintenance as natural teeth

DGI derives recommendation from the new classification scheme for periodontitis and peri-implantitis

‘Dental implants require the same maintenance as natural teeth – if not more. This prevents the inflammatory processes that can cause the loss of the artificial tooth root.’ This recommendation for implant patients issued by the German Society for Implantology (DGI) is derived from the new international classification scheme for periodontal diseases, which has recently been published.

For the first time, the classification also classifies diseases of the peri-implant tissues. As the DGI explains on the website idw online, the basis for the classification was provided by an international team of experts led by the president of the DGI, Dr Frank Schwarz of Frankfurt University Hospital.

Preserve the improved quality of life provided by implants

It is estimated that dentists in Germany place one million dental implants per year to close tooth gaps. This means that trimming of healthy neighbouring teeth to provide anchorage for a bridge, for example, can be avoided. Numerous studies have shown that most patients who have this type of restoration are satisfied and that their oral-health-related quality of life improves after treatment.

Nonetheless, the tissue around a dental implant can become inflamed, just as it can around natural teeth. As a group of Swedish researchers found out in a large follow-up study of almost 600 implant patients 9 years after treatment, almost a third of patients had peri-implant inflammation of the mucosa – a condition referred to by dentists as mucositis. In 45% of these patients, this inflammation had already spread to the jawbone – the bony tissue around the implant was reduced by more than half a millimetre. The diagnosis? ‘Peri-implantitis’.

Diagnosis of peri-implantitis

Inflammation of the mucosa (mucositis) is caused by dental plaque. If oral hygiene is poor, this plaque builds up on implant-supported restorations in exactly the same way it builds up on natural teeth. ‘If this plaque is thoroughly removed and the patient’s oral hygiene improves, this inflammation heals within a few weeks’, says DGI president Prof. Dr Frank Schwarz of Frankfurt University Hospital. If, however, the patient’s oral hygiene does not change and the inflammation remains untreated, it can progress and spread to the lower tissues.

It was previously thought that the complication of peri-implantitis could only occur many years after implantation. Experts now know that the disease can start at an earlier stage – two to three years after implantation.

The tissue is then visibly inflamed, and the existing periodontal pockets have grown deeper and bleed even on gentle examination with a probe. The recession of the bone can be seen on X-rays.

Prophylaxis is particularly important

The best way of treating peri-implantitis is not yet clear. Various concepts are being trialled at specialist centres. The only thing experts agree on so far is that the effectiveness of non-surgical treatments is usually limited.

And that is why prophylaxis is so important to the long-term success of implant treatment. ‘Patients who have chronic periodontitis, poor plaque control and no regular oral hygiene after implant treatment have an increased risk of peri-implantitis’, stresses DGI president Schwarz. ‘Regular follow-up examinations at the dentist and professional tooth cleanings are also important, and the frequency of these can be adapted according to the individual risk of the patient.’ It can therefore be a problem if implants are positioned during treatment in such a way that they impede home oral hygiene and dental aftercare – this is the experts’ message to their colleagues who place implants.

The classification scheme for peri-implant diseases is part of the new classification for periodontal diseases that has now been published in the specialist journals of the American Academy of Periodontology and European Federation of Periodontology. The publication is available as a special edition of the Journal of Clinical Periodontology at Wiley Online Library.

Conclusions regarding peri-implantitis in the new classification

For the first time, the new classification of periodontal diseases (which was presented at the EuroPerio9 conference in Amsterdam on 22 June 2018) includes peri-implant diseases and classifies them according to the clinical phenotypes of peri-implant health, peri-implant mucositis and peri-implantitis.

This classification is based on a publication about peri-implantitis that was published by a group of international co-authors led by DGI president Prof. Dr Frank Schwarz. Based on comprehensive reviews of the literature, the team of authors came to the following conclusions about peri-implantitis:

1) Peri-implantitis is a pathologic condition that occurs in the peri-implant tissues. It is characterized by inflammation in the peri-implant soft tissue and progressive bone loss.

2) The histopathologic and clinical factors that cause peri-implant mucositis to progress to peri-implantitis are not yet fully understood.

3) The onset of peri-implantitis can occur at an early stage during follow-up. The disease progresses in a non-linear and accelerating pattern.

4a) Tissue sites affected by peri-implantitis exhibit clinical signs of inflammation and increased probing depths compared with baseline measurements.

4b) Histologically, lesions in peri-implantitis sites are often larger than those in periodontitis sites.

4c) Surgical access to peri-implantitis sites often reveals a circumferential pattern of bone loss.

5a) There is strong evidence that patients with chronic periodontitis, poor plaque control and no regular oral hygiene after implant treatment have an increased risk of peri-implantitis. Data identifying smoking and diabetes as potential risk factors or indicators for peri-implantitis are inconclusive.

5b) There is some limited evidence to link peri-implantitis to other factors such as the post-restorative presence of submucosal cement, a lack of peri-implant keratinized mucosa, and positioning of implants that impairs oral hygiene and maintenance.

6) There is some evidence that progressive crestal bone loss around implants seldom occurs in the absence of clinical signs of soft tissue inflammation.

Article updated and factors added on 27 June 2018.

Cover photo: Prof. Frank Schwarz