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.




Complete overdentures retained by mini implants.

Posted Dental Elf 10/03/2017

Complete DenturesWith the advances in preventative dentistry one consequence has been patients becoming edentulous later in life. Accepting and adapting to conventional complete denture can be extremely challenging both physically and psychologically. There is now good evidence to support implant supported mandibular overdentures (Feine et al., 2002) using standard implants.
The aim of this review was to evaluate the use of mini-implants (diameter <3mm) to retain complete over-dentures in terms of survival, marginal bone loss, satisfaction and quality of life (Lemos et al, 2016).


The review followed the PRISMA statement (Moher et al., 2009) and was registered with PROSPERO.  Searches were conducted in PubMed/Medline, Embase and the Cochrane Library database checking articles published up to September 2016. In addition, they conducted a hand search of high impact journals in the field of implant retained prosthodontics. The eligibility criteria were, randomised controlled trials (RCTS) or prospective studies published in English. Two reviewers independently selected studies for inclusion, abstracted data and assessed risk of bias using the Newcastle-Ottawa Scale. The primary outcome was the survival rates of the mini implants; and the secondary outcomes included marginal bone loss, satisfaction and quality of life with the mini implants when they were used for retaining overdenture prosthesis.


  • 24 studies (4 RCTs, 20 prospective observational studies).
  • Risk of bias scores were 6 papers scored 9/9, 2 scored 8/9, 2 scored 7/9, 13 scored 6/9 and one paper scored 5/9
  • A total of 2492 mini implants and 386 standard implants were placed in 896 patients.
  • Mean age 65.93
  • No formal meta-analysis was carried out
  • Primary outcomes
    • Mini implant survival rate of 92.32% over 1-7 years
    • Maxillary arch implants had a higher failure rate at 31.17%
  • Secondary outcomes
    • Marginal bone loss below 1.5mm
    • Overdenture prosthesis retained by mini implants exhibited a significant increase in retention, stability chewing, speaking, comfort, aesthetics and improvements in satisfaction/quality of life.
    • Overdenture survival 90.58%


The authors concluded

Within the limitations of this study, the present systematic review indicates that the use of mini implants for retaining overdenture prosthesis may be considered an alternative treatment, since it presents high survival rates of mini implants, acceptable marginal bone loss, and improvements in variables related to satisfaction and quality of life of patients.


This systematic review adopted elements of the PRISMA protocol and identified a good number of prospective studies. A risk of bias analysis was undertaken with the authors scoring 10 papers as low risk of bias and 14 at a high risk of bias. Their outcome measurements were a combination of quantitative and qualitative data. Unfortunately, there was no meta-analysis undertaken and the survival rates given were missing both confidence intervals and a time frame. A quick review of the quantitative data provided by the review authors in table 2 revealed the mode for patients per study was 30 and the mode for follow-up was I year. The two comparison systematic reviews (Dantas et al, 2014; Raghoebar et al, 2014) which the authors concurred with reference high survival rates had similar extremely short follow-up periods and small sample sizes. The results from this systematic review therefore need to be interpreted with extreme caution due to problems with the external validity of the primary research and the synthesis of that data within the review.


Primary Paper

Lemos CA, Verri FR, Batista VE, Júnior JF, Mello CC, Pellizzer EP. Complete overdentures retained by mini implants: A systematic review. J Dent. 2017 Feb;57:4-13. doi: 10.1016/j.jdent.2016.11.009. Review. PubMed PMID: 27888049.

Other references

Dantas Ide S, Souza MB, Morais MH, Carreiro Ada F, Barbosa GA. Success and survival rates of mandibular overdentures supported by two or four implants: a systematic review. Braz Oral Res. 2014;28:74-80. doi: 10.1590/S1806-83242013000600012. Review. PubMed PMID: 24402059.

Feine JS, Carlsson GE, Awad MA, Chehade A, Duncan WJ, Gizani S, Head T, Lund JP, MacEntee M, Mericske-Stern R, Mojon P, Morais J, Naert I, Payne AG, Penrod J,Stoker GT, Tawse-Smith A, Taylor TD, Thomason JM, Thomson WM, Wismeijer D. The McGill consensus statement on overdentures. Mandibular two-implant overdentures as first choice standard of care for edentulous patients. Montreal, Quebec, May 24-25, 2002. Int J Oral Maxillofac Implants. 2002 Jul-Aug;17(4):601-2. Review. PubMed PMID: 12182304.

Moher D, Liberati A, Tetzlaff J, Altman DG; PRISMA Group.. Preferred reportingitems for systematic reviews and meta-analyses: the PRISMA statement. PLoS Med.2009 Jul 21;6(7):e1000097. doi:10.1371/journal.pmed.1000097. PubMed PMID:19621072; PubMed Central PMCID: PMC2707599.

Raghoebar GM, Meijer HJ, Slot W, Slater JJ, Vissink A. A systematic review of implant-supported overdentures in the edentulous maxilla, compared to the mandible: how many implants? Eur J Oral Implantol. 2014 Summer;7 Suppl 2:S191-201. Review. PubMed PMID: 24977255.

Raghoebar, G. M., Meijer, H. J. A., Slot, W., Slater, J. J. R. and Vissink, A. (2014) ‘A systematic review of implant-supported overdentures in the edentulous maxilla, compared to the mandible: how many implants?’, European journal of oral implantology, 7 Suppl 2(November 2016), pp. S191-201.


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.