Antibiotic therapy as an adjunct to scaling and root planing in smokers


It has long been established that smoking is a significant modifying factor in the progression of periodontal disease and eventual tooth loss (Dietrich et al. 2015; Zeng et al. 2014). The established treatment of periodontal disease is based on the elimination of pathogens through subgingival scaling and root planing (SRP), if periodontal disease remains following this initial ‘hygienic phase’ then treatment can be repeated with the addition of systemic antibiotics too good effect (Keestra et al. 2014; Rabelo et al. 2015). Thus, the aim of this study is to conduct a systematic review and meta-analysis to evaluate the effectiveness of systemic antibiotic therapy associated with periodontal treatment in smokers.


This review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement with the focused question; “Do adjunctive antimicrobials improve the clinical outcome of non-surgical therapy (scaling and root planing [SRP]) in the treatment of periodontitis in smokers?”

The following inclusion criteria were applied:  Randomized controlled clinical trials; studies published in English; studies with smoker patients (at least 10 cigarettes per day for at least five years) diagnosed with chronic periodontitis; patients without significant systemic diseases ; aged between 30 and 70 years; not receive periodontal treatment in the last six months; used systemic antibiotic therapy associated with periodontal treatment; present the results of the test and control groups, and  assessments of clinical periodontal parameters such as probing depth (PD), bleeding on probing (BOP) and clinical attachment level (CA). Exclusion criteria were local antibiotic therapy and trials not published in English.

Two researchers independently selected and screened the articles. Data bases were searched from July 1994 to August 2016. The included databases were MEDLINE, Cochrane Controlled Clinical Trial Register, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, CINAHL, Science Direct, and ISI Web of Knowledge, Scopus, and manually searched relevant specialist journals. Quality assessment was undertaken using the Jadad scale.


The systematic Search found 3 papers out of 68 which fulfilled the inclusion criteria for meta-analysis. On the JADAD risk of bias assessment only 8/30 studies were evaluated as high quality.

Meta-analysis results (Primary outcomes)

Mean Difference Probing Depth (p = 0.0359   MD -0.32,   95% CI -0.50 – -0.14)
Mean Difference Clinical Attachment level (p = 0.0161   MD -0.22,   95% CI -0.39 – -0.06)
Mean Difference Bleeding on Probing (p = 0.446     MD -0.04,   95% CI -0.13– 0.06)

 Author’s Conclusion

“The results of our meta-analysis reveal the clinical benefits of systemic antibiotics as an adjunct to the non-surgical periodontal treatment of smokers. These clinical improvements, although statistically significant, appeared to be of little clinical relevance.”


In the discussion, the author goes to considerable length to explain the effectiveness for the adjunctive use of antibiotics in the periodontal treatment of smokers and to their credit also the lack of clinical relevance. There are three important points to be made here:

  • The degree of precision in the published mean difference of this paper is 0.005mm. The maximum precision possible with a standard periodontal probe is 0.5mm, and in the surgery the measurements are mostly taken as whole numbers. Mosteller described the issue this way:

“The number of significant figures gives a hint of accuracy. For example, 98.2o has three significant figures and might be regarded as correct to within 0.05o (One should not count on this level of accuracy.) Therefore, in these ambiguous circumstances, the author should tell what degree of accuracy is intended, as nearly as possible”(Mosteller 1992)


  • It is not an uncommon finding in primary research that the test groups and the trials time-frame are far too small to derive any precise/useful statistical results; this is something authors need to be addressed at the planning and protocol registration stage.


  • Additionally in the primary research the subjects continued to smoke throughout the duration of the trial, therefore it is hardly surprising there is no improvement in the results, the damaging effect of the smoking drowning out the benefit of the antibiotics. It is generally accepted that tobacco smoking remains the leading single risk to health in high-income North America and Western Europe by quite a large margin. (Lim et al. 2012).


Primary Paper

Assem, N.Z. et al., 2017. Antibiotic therapy as an adjunct to scaling and root planing in smokers: a systematic review and meta-analysis. Brazilian Oral Research, 31, pp.1–15. Available at:

Additional references

Dietrich, T. et al., 2015. Smoking, Smoking Cessation, and Risk of Tooth Loss: The EPIC-Potsdam Study. Journal of dental research, 94(10), pp.1369–75.

Keestra, J.A.J. et al., 2014. Non-surgical periodontal therapy with systemic antibiotics in patients with untreated chronic periodontitis: A systematic review and meta-analysis. Journal of Periodontal Research, (32), pp.689–706.

Lim, S.S. et al., 2012. A comparative risk assessment of burden of disease and injury attributable to 67 risk factors and risk factor clusters in 21 regions, 1990-2010: A systematic analysis for the Global Burden of Disease Study 2010. The Lancet, 380(9859), pp.2224–2260.

Mosteller, F., 1992. Writing about numbers. In Medical uses of statistics. Boston: NEJM Books, pp. 375–89.

Rabelo, C.C. et al., 2015. Systemic antibiotics in the treatment of aggressive periodontitis. A systematic review and a Bayesian Network meta-analysis. Journal of Clinical Periodontology, 42(7), pp.647–657.

Zeng, J. et al., 2014. Reexamining the Association Between Smoking and Periodontitis in the Dunedin Study With an Enhanced Analytical Approach. Journal of Periodontology, 85(10), pp.1390–1397. Available at:





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.