Impact of Debridement Invasiveness on Attachment Gain After Antiinfective Periodontal Therapy
Phase: NA
Conditions: Periodontitis, Periodontal Attachment Loss, Periodontal; Lesion
Sponsor: Wuerzburg University Hospital

 
1 
Study protocol 
 
Effect of Influence of invasiveness of subgingival debridements on 
attachment gain after anti-infective periodontal therapy 
 (ATTGAIN16)  
V1.2 vom 16.3.2016 
 
 
 
 
 
Introduction 
The main issue of non-surgical as well as surgical periodontal therapy is the 
elimination of vital and mineralized bacterial biofilm by mechanical plaque removal. 
Particularly in the context of surgical periodontal therapy, the mechanical plaque 
removal is accompanied by the disposal of granulation tissue. 
Current studies, however, suggest that this may be a wrong approach, since the 
deeper, infra-alveolar soft tissue of periodontal lesions ≥ 5 mm probing depth seems 
to have a pronounced regenerative capacity after resolution of the periodontal 
inflammation4-6.  
The conventional manual instrumentation of the root surfaces with curettes or 
ultrasound scaler resolves the root cement in a layer thickness of on average 24 ± 18 
μm, respectively 20 ± 15 μm9. However, the opportunity of a regenerative 
Reattachment would be improved significantly by the retention the root cement. 
Therefore, the aim of any minimal invasive periodontal therapy is the elimination of 
the soft/vital bacterial biofilm with the least possible preservation of the existing 
cement layer with the disclaim of surgical approaches and the explicit elimination of 
granulation tissue. 
In this context the use of subgingival air polishing devices seems to be a promising 
option10 11. Various studies have confirmed the efficiency of subgingival air polishing 
devices for biofilm removal in a comparable magnitude to ultrasound scales or a 
combination of hand instruments and ultrasound scales11-13. By using a subgingival 
air polishing devices Bacterial plaque can be removed up to a pocket depth of 5 mm 

 
2 
without damaging the treated root surfaces14, 15. Also an alternative cleaning powder 
of smaller grain size based on the sugar alcohols Erythritols has been performed 
successfully in randomized clinical trials16, 17. 
 
 
 
 
 
 
Study objective 
This study aims to evaluate whether a two-stage anti-infective periodontal treatment 
strategy, comprising a minimally invasive removal of only soft microbial biofilms with 
an air polish in the first step and a debridement of subgingival dental calculus with 
air-scaler and abrasors in a second step, results in a greater reduction of the 
periodontal attachment level, than a single step strategy, with a sub and 
supragingival mechanical debridement of soft and mineralized bacterial biofilms at 
the same time. 
The study will be conducted with periodontal patients with deep infra-bony defects. 
 
 
Material und Methoden 
 
study population 
Patients of both sexes with untreated, severe chronic or aggressive periodontitis will 
be recruited for the study. 
 
inclusion criteria 
- at least 15 natural teeth still in situ 
- at least 1 tooth with periodontal pocket depths ≥ 6 mm and infra-alveolar bone 
defect 
- Age ≥ 18 years 
 
exclusion criteria 
- systematic perodontal therapy ≤ 12 months before the screening time  

 
3 
- need for antibiotic prophylaxis before dental care 
- untreated systemic diseases that interfere with periodontal healing (eg: uncontrolled 
diabetes mellitus). 
 
 
 
 
 
 
 
 
Study design 
 
1. Baseline examination and group assignment  
All patients who meet the inclusion criteria, will be informed about the study 
objectives and will give their written consent. 
 
The following parameters will be recorded at the beginning of the study on all teeth: 
 
1. Probing Attachment Level (PAL) 
(6 sites: mesiobuccal, buccal, distobuccal, mesiooral, oral, distooral) 
 
2. Probing Pocket Depth (PPD) 
 (6 sites: mesiobuccal, buccal, distobuccal, mesiooral, oral, distooral) 
 
3. Bleeding on probing (BoP) (6 measuring points / tooth) 
(6 sites: mesiobuccal, buccal, distobuccal, mesiooral, oral, distooral) 
 
4. Gingival Index (GI) 
(each 1 measuring point on the buccal tooth surfaces) 
 
5. Plaque Control Record (PCR) 
(4 measuring points: mesial, buccal, distal, oral) 
 
 

 
4 
Subsequently, microbial samples will be taken from the deepest gingival pocket per 
jaw quadrant with the help of sterile paper tips and stored in Eppendorf tubes at -20 
C until further analysis. 
 
After baseline examination, the study patients will be randomly assigned to the test or 
the control group with a computer-generated block randomization list. Randomization 
will be stratified for smokers and non-smokers. 
 
 
Antiinfective therapy 
 
The anti-infective therapy will be scheduled promptly within a maximum of 10 days 
after the Baseline Visit. 
 
Antiinfective therapy test group: 
All patients of the test group receive a supra- and subgingival removal of all tooth 
adherent soft bacterial biofilms in 1-2 sessions, but within 24 h, with a low-abrasive 
erythritol-based cleaning powder (Air-Flow Pulver Plus, EMS, Nyon, Switzerland). 
Only supra- and paragingival calculus will be dislodged with sonic / ultrasonic 
scalers. The presence of subgingival calculus will only be documented. However, an 
additional mechanical subgingival instrumentation of exposed root surfaces by f 
scaling and root planing to remove subgingival calculus will not be performed at this 
time. 
 
Antiinfective therapy control group: 
All patients of the control group receive a supra- and subgingival removal of all tooth 
adherent soft bacterial biofilms in 1-2 sessions within 24 h too, but by using hand 
scalers and curettes, sonic / ultrasonic scalers, rubber cup and polishing paste. 
In contrast to the test group, all exposed subgingival root surfaces will be 
instrumented to remove all adherent mineralized subgingival calculus. 
  
1. Reevaluation  
The 1st re-evaluation is scheduled 28 days (+ 7 days) after completion of anti-
infectious periodontal therapy.  

 
5 
PAL, PPD, BoP, GI, and PCR will be re-recorded on all teeth and for patients from 
the test and the control group and subgingival microbial samples of the deepest 
pockets in each quadrant will be taken again. Plaque will subsequently be visualized 
by staining. All patient gains oral hygiene instructions to improve the efficiency of 
domestic plaque control by appropriate brushing techniques and aids (dental floss / 
interdental brushes). 
All patients of in the test group, will receive a subgingival instrumentation using 
curettes or ultrasound scalers to subduct the subgingival calculus which just has 
been documented initially, but not removed. 
2. Reevaluation  
The 2nd reevaluation is scheduled 56 days (+7 days) after the 1st reevaluation visit. 
 
The parameters PAL, PPD, BoP, GI and PCR will be reassessed in all study patients 
again. Any remaining oral hygiene deficiencies will be rediscovered by staining, and 
oral hygiene instructions and suitable brushing techniques will be demonstrated 
again. Teeth persistent bleeding on probing during reevaluation visit will be 
subgingivally instrumented with curettes or ultrasound scalers in the control group. 
The test group will receive a subgingival air polish cleaning with the low-abrasive 
erythritol-based cleaning powder. 
 
Close out visit 
168 days ± 7 days after the first visit (84 days after the second reevaluation), the 
close out visit is scheduled. The parameters PAL, PPD, BoP, GI and PCR will be 
reassessed again and microbial samples from the deepest gingival pocket per 
quadrant will be taken again. 
 
 
Microbiological analyzes 
The collected pooled microbiological samples will be analyzed for the presence of the 
periodontitis-associated microorganisms Porphyromonas gingivalis, Tannerella 
forsythia, Treponema denticola and Aggregatibacter actinomycetemcomitans using a 
commercially available bacterial gene probe test (Carpegen Perio Diagnostik, 
Carpegen GmbH, Münster). It is also planned to carry out a total genome sequencing 
of the subgingival microbiome taken from the pockets on all collected microbial 
samples. 
 

 
6 
Statistical analysis 
 
Primary endpoint 
The primary endpoint of the study is the reduction of the probing attachment level 
(PAL) between baseline and the final study after 168 days. 
 
Secondary endpoints 
As secondary endpoints the pocket depth (PPD), bleeding on probing (BoP), the 
gingival index (GI), the plaque control record (PCR), and changes in the composition 
of the subgingival pocket microflora will be evaluated. 
 
 
Sample size 
Assuming an average reduction of an attachment level of -2.0 mm in the control 
group between baseline and second reevaluation and an assumed standard 
deviation of ± 0.6 mm, the difference between the test and control group is 0.6 mm 
for a test strength of 0.9 and an error probability of p≤0.05, a group size of 2 x 22 
patients is required. 
 
 
 
 
 

 
7 
References 
 
1. 
Renvert S, Persson GR. A systematic review on the use of residual probing 
depth, bleeding on probing and furcation status following initial periodontal therapy to 
predict further attachment and tooth loss. J Clin Periodontol 2002;29 Suppl 3:82-9; 
discussion 90-1. 
 
2. 
Grbic J, Lamster I. Risk indicators for future clinical attachment loss in adult 
periodontitis. Tooth and site variables. Journal of Periodontology 1992;63:262-69. 
 
3. Armitage G. Periodontal disease: diagnosis.  
Annals of Periodontology 1996;1:37-215. 
 
4. Gargiulo A, Wentz F, Orban B. Dimensions and relations of the dento-gingival 
junction in human. Journal of Periodontology 1961;32:261-67. 
 
5. Carnevale G. Fibre retention osseous resective surgery: a novel conservative 
approach for pocket elimination. Journal of Clinical Periodontology 2007;34:182-87. 
 
6. Lindhe J, Berglundh T, Ericsson I, Liljenberg B, Marinello C. Experimental 
breakdown of peri-implant and periodontal tissues. A study in the beagle dog.  
Clin Oral Implants Res 1992;3(1):9-16. 
 
7. Levine H, Stahl S. Repair following periodntal flap surgery with the retention of 
gingival fibres. Journal of Periodontology 1972;43(99-103). 
 
8. Carnevale G, Sterrantino S, di Febo G. Soft and hard tissue wound healing 
following tooth preparation to the alveolar crest. International Journal of Periodontics 
& Restorative Dentistry 1983;3:36-53. 
 
9. Rupf S, Brader I, Vonderlind D, et al. In vitro, clinical and microbiological 
evaluation of a linear oscillating device for scaling and root planing. Journal of 
Periodontology 2005;76:1942-49. 
 
10. Schwarz F, Bieling K, Venghaus S, et al. Infliuence of fluorescence-controlled 
Er:YAG laser radiation, the Vector system and hand instruments on periodontally 
diseased root surfaces in vivo. Journal of Clinical Periodontology 2006;33:200-08. 
 
11. Guentsch A, Preshaw PM. The use of a linear oscillating device in periodontal 
treatment: a review. J Clin Periodontol 2008;35(6):514-24. 
 
12. Hahn R. The Vector method: clinical application and scientific background (in 
german). Parodontologie 2000;1 (Special Issue):1-7. 
 
13. 
Horodko M, Bürklin T, Ratka-Krüger P, Raetzke P. Klinische Untersuchung zur 
Wirksamkeit eines neuen Ultraschallgerätes bei der nichtchirurgischen 
Parodontitistherapie. Parodontologie 2002;13:297. 
 
14. Petersilka GJ. Subgingival air-polishing in the treatment of periodontal biofilm 
infections. Periodontol 2000 2011;55(1):124-42. 
 

 
8 
15. 
Petersilka GJ, Bell M, Haberlein I, et al. In vitro evaluation of novel low 
abrasive air polishing powders. J Clin Periodontol 2003;30(1):9-13. 
 
16. Hagi TT, Hofmanner P, Eick S, et al. The effects of erythritol air-polishing powder 
on microbiologic and clinical outcomes during supportive periodontal therapy: Six-
month results of a randomized controlled clinical trial.  
Quintessence Int 2015;46(1):31-41. 
 
17. 
Hagi TT, Hofmanner P, Salvi GE, Ramseier CA, Sculean A. Clinical outcomes 
following subgingival application of a novel erythritol powder by means of air 
polishing in supportive periodontal therapy: a randomized, controlled clinical study. 
Quintessence Int 2013;44(10):753-61. 
 
18. 
Lange DE, Plagmann HC, Eenboom A, Promesberger A. Clinical methods for 
the objective evaluation of oral hygiene.  
Deutsche Zahnärztliche Zeitschrift 1977;32:44-47.