Peri-implantitis: lack of high quality studies for surgical regenerative treatment

implant astra

Implant treatment has a well-established body of evidence supporting its long-term success and efficacy. Following in the shadow of this success however we now have the problem of peri-implantitis, characterised by inflammation and degeneration of the hard and soft tissues surrounding the implant and eventually leading to its loss from the jaw bone. Various techniques have been advocated to treat this infection taking its origins from periodontal treatment such as non-surgical, surgical and regenerative procedures.

The purpose this study was to systematically review the literature on the surgical regenerative treatment of the peri-implantitis and to determine an effective therapeutic predictable option for its clinical management.


The review followed the PRISMA statement  (Moher et al. 2009) the protocol was also registered on the International Prospective Register of Systematic Reviews (PROSPERO) database. Searches were carried by two independent researchers using Ovid MEDLINE, PubMed, Embase, and Dentistry and Oral Sciences Source. Databases were searched from January 2006 to March 2016 and restricted to English, manual searches were also carried out in the relevant major journals. Inclusion criteria were: Human prospective and retrospective observational studies involving at least one surgical regenerative treatment method for peri-implantitis. Minimum sample size was 10 implants with no less than 12 months follow-up. Excluded studies included animal and in vitro studies, patients with uncontrolled systemic disease that put the implant at risk and ceramic or coated implants. Quality appraisal was carried out by two independent reviewers using the Cochrane Collaboration tool for assessing risk of bias in randomised trials (Higgins JPT et al. 2011)


  • From 883 records only 18 fulfilled the inclusion criteria. This included 8 prospective clinical studies, seven case series and three randomised clinical trials (RCT’s). A total of 528 patients with 713 implants were treated.
  • 2 studies were at low risk of bias, 1 moderate, and 3 high. The remainder were classified as unclear.
Total mean radiological bone level change +2.97 mm (95% CI 1.58 to 2.35)
·       Mean radiological bone level + membrane +1.86 mm (95% CI 1.36 to 2.36)
·       Mean radiological bone level – membrane +2.12 mm (95% CI 1.46 to 2.78)
·       Mean radiological bone level submerged +2.17 mm (95% CI 1.87 to 2.47)
·       Mean radiological bone level non-submerged +1.91 mm (95% CI 1.44 to 2.39)
Total mean probing depth change -2.78 mm (95% CI 2.31 to 3.25)
·       Mean probing depth change + membrane -2.88 mm (95% CI 2.31 to 3.45)
·       Mean probing depth change – membrane -2.60 mm (95% CI 1.90 to 3.30)
·       Mean probing depth change submerged -2.68 mm (95% CI 1.71 to 3.64)
·       Mean probing depth change non-submerged -2.77 mm (95% CI 2.23 to 3.30)
Total mean bleeding on probing change -55% (95% CI 45.2 to 64.4)



The authors concluded: –

Within the limits of this systematic review, surgical regenerative treatment is a predictable option in managing peri-implantitis and improving clinical parameters of peri-implant tissues. There is no fundamental advantage of membrane use for bone graft coverage or submergence of the healing site on the final outcome of peri-implant defect regeneration. Due to the limited number of randomised clinical trials, at the time there is a lack of scientific evidence in the literature regarding the superiority of the regenerative versus non-regenerative surgical treatment


There are a few points to mention in relation to this well conducted review. Firstly, there is a lack of high quality studies with only 2 out of the 18 fulfilling the criteria and how this might influence the overall meta-analysis (this is commonly missed out in dental related systematic reviews, even though it is one of the PRISMA criteria the authors mention they adhere to). PRISMA has since been updated (Moher et al. 2015).   Secondly, the risk of bias tool is designed for RCT’s (3/18) and there was no mention of using one of the tools specifically designed for non-randomised observational studies (Sterne et al. 2016; Wells 2013).

Finally, the author concludes that surgical regenerative treatment is a predictable option for the treatment of peri-implantitis but fails to mention how well or poorly this performs against standard non-regenerative debridement of the lesion. The reason I mention this is that a second paper was published by members of the same team, in the same institution, in the same month that could have shed some light on clinical effectiveness (Ramanauskaite et al. 2016).

First Posted on the National Elf Service


Primary paper

Daugela P, Cicciù M, Saulacic N. Surgical Regenerative Treatments for Peri-Implantitis: Meta-analysis of Recent Findings in a Systematic Literature Review. J Oral Maxillofac Res. 2016 Sep 9;7(3):e15. eCollection 2016 Jul-Sep. Review. PubMed PMID: 27833740; PubMed Central PMCID: PMC5100640.

Other references

Original review protocol on PROSPERO

Higgins JP, Altman DG, Gøtzsche PC, Jüni P, Moher D, Oxman AD, Savovic J, Schulz KF, Weeks L, Sterne JA; Cochrane Bias Methods Group; Cochrane Statistical Methods Group. The Cochrane Collaboration’s tool for assessing risk of bias in randomised trials. BMJ. 2011 Oct 18;343:d5928.

Sterne JA, Hernán MA, Reeves BC, et al. ROBINS-I: a tool for assessing risk of bias in non-randomised studies of interventions. BMJ. 2016 Oct 12;355:i4919. doi: 10.1136/bmj.i4919. PubMed PMID: 27733354; PubMed Central PMCID: PMC5062054.

Wells, G.A., 2013. Newcastle Ottawa scale Coding Manual for Case-Control Studies. The Ottawa Hospital Research Institute.

Ramanauskaite A, Daugela P, Faria de Almeida R, Saulacic N. Surgical Non-Regenerative Treatments for Peri-Implantitis: a Systematic Review. J Oral Maxillofac Res. 2016 Sep 9;7(3):e14. eCollection 2016 Jul-Sep. Review. PubMed PMID: 27833739; PubMed Central PMCID: PMC5100639.




The Holy-Mouth-Men (Body Rituals of the Nacirema by H.Miner)

I love this research paper published  in American Anthropologist, vol 58, June 1956. pp. 503-507. 

Cosmetic Dentistry 1914
African Cosmetic Dentistry 1914 ( Pitt-Rivers Museum)

“In the hierarchy of magical practitioners, and below the medicine men in prestige, are specialists whose designation is best translated as “holy-mouth-men.” The Nacirema have an almost pathological horror of and fascination with the mouth, the condition of which is believed to have a supernatural influence on all social relationships. Were it not for the rituals of the mouth, they believe that their teeth would fall out, their gums bleed, their jaws shrink, their friends desert them, and their lovers reject them. They also believe that a strong relationship exists between oral and moral characteristics. For example, there is a ritual ablution of the mouth for children which is supposed to improve their moral fiber.

The daily body ritual performed by everyone includes a mouth-rite. Despite the fact that these people are so punctilious[4] about care of the mouth, this rite involves a practice which strikes the uninitiated stranger as revolting. It was reported to me that the ritual consists of inserting a small bundle of hog hairs into the mouth, along with certain magical powders, and then moving the bundle in a highly formalized series of gestures[5].

In addition to the private mouth-rite, the people seek out a holy-mouth-man once or twice a year. These practitioners have an impressive set of paraphernalia, consisting of a variety of augers, awls, probes, and prods. The use of these items in the exorcism of the evils of the mouth involves almost unbelievable ritual torture of the client. The holy-mouth-man opens the client’s mouth and, using the above mentioned tools, enlarges any holes which decay may have created in the teeth. Magical materials are put into these holes. If there are no naturally occurring holes in the teeth, large sections of one or more teeth are gouged out so that the supernatural substance can be applied. In the client’s view, the purpose of these ministrations[6] is to arrest decay and to draw friends. The extremely sacred and traditional character of the rite is evident in the fact that the natives return to the holy-mouth-men year after year, despite the fact that their teeth continue to decay.

It is to be hoped that, when a thorough study of the Nacirema is made, there will be careful inquiry into the personality structure of these people. One has but to watch the gleam in the eye of a holy-mouth-man, as he jabs an awl into an exposed nerve, to suspect that a certain amount of sadism is involved. If this can be established, a very interesting pattern emerges, for most of the population shows definite masochistic tendencies. It was to these that Professor Linton referred in discussing a distinctive part of the daily body ritual which is performed only by men. This part of the rite includes scraping and lacerating the surface of the face with a sharp instrument. Special women’s rites are performed only four times during each lunar month, but what they lack in frequency is made up in barbarity. As part of this ceremony, women bake their heads in small ovens for about an hour. The theoretically interesting point is that what seems to be a preponderantly masochistic people have developed sadistic specialists.

Methodological Quality of Consensus Guidelines in Implant Dentistry (Faggion et al. 2017)

Clinicians rely heavily on consensus guidelines when they develop treatment protocols for their patients. The idea is that the most experienced clinicians and academics meet and systematically develop what they feel is best practice in their particular field. Health care providers and regulators then rely on this distillation of knowledge, experience and evidence in their decision making. A systematic review of guideline quality in peer-reviewed medical literature was conducted in 1999  and found only a 43% adherence to reporting standards (Shaneyfelt et al. 1999). In 2003, a generic tool was created by the AGREE (Appraisal of Guidelines, REsearch and Evaluation) collaboration to create “common standards to improve the quality process and reporting of guideline development” (Cluzeau et al. 2003). With use the protocol evolved into AGREE II (Brouwers et al. 2010) which is made up of 23 items in 6 domains:

  1. Scope and Purpose
  2. Stakeholder Involvement
  3. Rigour of Development
  4. Clarity of Presentation
  5. Applicability
  6. Editorial Independence

The research question reference consensus guidelines in implant dentistry was: “Do consensus guidelines published in high ranked implant journals meet the requirements proposed in the AGREE II instrument? A secondary objective was to evaluate whether the inclusion of systematic reviews conducted to support the consensus guidelines improved their methodological quality.


Two authors (KA,MA) independently searched and evaluated consensus guidelines from the 6 highest impact implant dentistry journals (assigned by Journal Citation Reports) and Medline database via PubMed. The search was limited to May 2009 – February 2016 in line with the publication of AGREE II. Reasons for papers to be excluded was recorded.

Four authors (KA,TA,LM,MA), following assessor training then independently applied the AGREE II tools to the consensus guidelines as described in the user’s manual. Domain scores were presented as median percentages of the maximum possible with their respective interquartile ranges. Domain scores were divided into consensus guidelines, and consensus guidelines with systematic reviews.


  • From an initial 258 publications 27 consensus guidelines fulfilled the inclusion criteria of which 19 was included for comparison
  • The journals were: Clinical Oral Implants Research (COIR), Clinical Implant Dentistry and Related Research (CIDRR), European Journal of Oral Implants (EJOI), The International Journal of Oral and Maxillofacial Implants (JOMI), Journal of Oral Implantology, and Implant Dentistry.
  • 26 guidelines were developed after meetings in Europe.
  • The European Association of Osseointigration (EAO) developed the most guidelines (n=9)
  • The number of authors ranged from 2-27 (median, 9)

Primary Outcomes

AGREE II Domains Consensus guidelines only.

Median is % of maximum score

Consensus guidelines plus systematic reviews.


Domain 4 (Clarity of presentation) Median, 75; (IQR 15.30) Median, 84.70;(IQR, 9.80).
Domain 1 (Scope and Purpose) Median, 69.40; (IQR, 36.20). Median, 79.20; (IQR, 73)
Domain 2 (Stakeholder Involvement) Median, 41.70; (IQR, 17.70) Median, 76.40; (IQR,18.10)
Domain 6 (Editorial Independence) Median, 41.7 ;(IQR, 83.30) Median, 56.30 (IQR, 34.40)
Domain 3 (Rigour of Development) Median, 30.70; (IQR, 26.50) Median, 50 (IQR,44.40)
Domain 5 (Applicability) Median, 26;(IQR, 12.50) Median, 26; (IQR, 20.80)

Conclusion (the author concluded)

“Methodological improvement of consensus guidelines published in major implant dentistry journals is needed. The findings of the present study may help researchers to better develop consensus guidelines in implant dentistry, which will improve the quality and trust of information needed to make proper clinical decisions”.


For the clinician in practice placing or restoring on dental implants this is a very important paper and goes a long way in explaining the disjoint between what is presented on the international conference circuit and what we see in day-day practice.

To help with interpreting the authors data I have modified it slightly to present the data as median with 95% confidence intervals and place the meta-analysis it in a forest plot.

The first chart show the AGREE II scores relating to the consensus guidelines that did not include the use of systematic reviews. The highest scoring domains were Domain 4. (Clarity of Presentation) and Domain 1. (Scope and Purpose) which score in the 70’s. There is a gap and the next four Domains in rank order are; 6. (Editorial Independence), 2. (Stakeholder Involvement), 3. (Rigour of Development) and lastly 6. (Applicability). These narrative guidelines therefore only fulfil 50% of the AGREE II criteria.

Agree II narr

The second chart show a meta-analysis comparing the narrative guideline scores compared with the consensus guidelines + systematic reviews, and there is roughly a 9% improvement bringing the score up to 60% compliance with AGREE II.

Forest plot

What becomes obvious however is that 18% improvement came out of Domain 3. (Rigour of Development) but 34% from Domain 6. (Editorial Independence). Going back then to the meta-analysis of consensus guidelines + systematic reviews the improvement has been weak and polarises the results.

Agree II SR

From a clinicians point of view what options do we have available to us to improve consensus guidelines?


  • Domains 1 (Scope and Purpose) and 4 (Clarity of Presentation) are good, we know what questions to ask and how to present them.
  • Domain 6 (Editorial Independence) is improving but there still needs to be more clarity over the editorial independence from funding bodies and conflicts of interest from the funding bodies and authors.
  • Domain 3. (Rigour of Development) More effort needs to be spent in this area as is is the foundation on which the guidelines are built, based on validated systematic methods for assessing and analysing the relevant primary research. Analysis also needs to include health benefits, side effects and complications. The guidelines should also be externally validated prior to publication.
  • Domain 2 (Stakeholder Involvement) at present is dominated by University professors and private practitioners with strong academic connections. This area would benefit from the views of clinicians working outside of specialist practice, health care providers, funders and patient groups.
  • Domain 6. (Applicability) is the weakest domain, this may be in part due to the lack of input at the stakeholder level . For clinicians in practice, and their patients cost implications are a major barrier to applying guideline recommendations.


 Primary paper

Faggion, C.M.J. et al., 2017. Methodological Quality of Consensus Guidelines in Implant Dentistry. PloS one, 12(1), p.e0170262. Available at:

 Other references

Brouwers, M.C. et al., 2010. AGREE II: Advancing guideline development, reporting and evaluation in health care. Journal of Clinical Epidemiology, 63(12), pp.1308–1311.

Cluzeau, F. et al., 2003. Development and validation of an international appraisal instrument for assessing the quality of clinical practice guidelines: the AGREE project. Quality & safety in health care, 12(1), pp.18–23. Available at:

Shaneyfelt, T.M., Mayo-Smith, M.F. & Rothwangl, J., 1999. Are guidelines following guidelines? JAMA: The Journal of the American Medical Association, 281(20), pp.1900–1905.