Re-submission to Journal of Clinical Periodontology
Title
A randomized controlled trial on immediate surgery versus root planing in patients with
advanced periodontal disease: a cost-effectiveness analysis
Running title
Cost-effectiveness of periodontal treatment alternatives
Keywords
Periodontitis, randomized controlled trial, surgery, scaling and root planing, costeffectiveness, azithromycin
Authors
Seyed Reza Miremadi, Hugo De Bruyn, Harold Steyaert, Katrijn Princen, Mehran Moradi
Sabzevar, Jan Cosyn
Affiliations and Institutions
Miremadi SR1, De Bruyn H1,2, Steyaert H1, Princen K1, Sabzevar MM3, Cosyn J1,3
1
University of Ghent, Faculty of Medicine and Health Sciences, Dental School, Department of
Periodontology and Oral Implantology, De Pintelaan 185, B-9000 Ghent, Belgium
2
Malmö University, Faculty of Odontology, Department of Prosthodontics, 205 06 Malmö,
Sweden
3
Free University of Brussels (VUB), Faculty of Medicine and Pharmacy, Dental Medicine,
Laarbeeklaan 103, B-1090 Brussels, Belgium
Contact address corresponding author
Seyed Reza Miremadi
University of Ghent, Faculty of Medicine and Health Sciences, Dental School, Department of
Periodontology and Oral Implantology, De Pintelaan 185, B-9000 Ghent, Belgium
E-mail: resa.miremadi@ugent.be
Conflict of interest and source of funding statement
The authors declare that they have no conflicts of interest. This study was supported by
departmental funds.
Clinical relevance
Scientific rationale for the study: Studies focusing on cost-effectiveness of periodontal
treatment are scarce. Yet, considering the limitations in individual and social economic
resources, an economic assessment of different treatment modalities is an important issue.
Principal findings: Immediate surgery and SRP, both followed by re-debridement and
systemic azithromycin at 6 months, were equally effective in terms of clinical outcome.
Surgery was significantly more expensive than SRP, but proved more beneficial in terms of
supportive care and the need for systemic antibiotics.
Practical implications: Surgery yields higher cost than SRP, but may reduce the need for
supportive care and systemic antibiotics.
ABSTRACT
Aim: To compare immediate surgery to scaling and root planing (SRP) in the treatment of
advanced periodontal disease focusing on the prevalence of residual sites and costeffectiveness (1); to evaluate the adjunctive effects of azithromycin in a second treatment
phase (2).
Materials and methods: Thirty-nine patients (18 males, 21 females; mean age: 54.6)
received oral hygiene instructions and were randomly allocated to surgery (n=19) or SRP
(n=20). Patients with residual pockets (≥6 mm) at 6 months received re-debridement of these
sites and systemic azithromycin. Treatment groups were followed up to 12 months and
evaluated in terms of clinical response parameters and cost-effectiveness. Chair-time was
used to assess the financial impact of treatment.
Results: Both treatment arms were equally effective in terms of clinical outcome
demonstrating less than 1 % residual pockets at 12 months. Surgery imposed an extra 746
Euro on the patient up to 6 months when compared to SRP. At 12 months, 46 Euro of this
amount could be offset as a result of a reduced need for supportive care. Only 6 patients in the
surgery group needed systemic antibiotics, whereas 14 patients in the SRP needed such
additional treatment.
Conclusions: Although 700 Euro could be saved on average by performing SRP instead of
surgery, the latter significantly reduced the need for supportive care and systemic antibiotics.
Introduction
The treatment of chronic periodontitis aims at arresting the inflammatory process of the
disease through subgingival biofilm removal (Heitz-Mayfield et al., 2002). This can be
performed using non-surgical and surgical approaches leading to significant clinical
improvements, provided the patient maintains an adequate oral hygiene throughout the
treatment and the maintenance phase (Lindhe and Nyman, 1975, Axelsson and Lindhe, 1981).
The choice of the treatment approach can be a matter of debate. The traditional treatment
concept includes plaque control measures and non-surgical scaling and root planing (SRP)
followed by surgical re-treatment where indicated. A number of reasons can motivate this
staged treatment concept. For one thing, peroperative conditions may be more favorable when
marginal inflammation has subsided after non-surgical debridement. On the other hand,
surgical treatment is usually needed in patients with advanced periodontal disease and
therefore surgery without non-surgical pre-treatment could be considered valuable in these
patients. Hence, the primary objective of the present clinical study was to compare the clinical
outcome of immediate surgery to traditional SRP in patients with advanced periodontal
disease focusing on residual or poorly responding sites and cost-effectiveness. The research
hypothesis was that surgery would result in less residual sites when compared to SRP, yet at
significantly higher cost.
Residual sites are usually treated by means of systemic antibiotics when all mechanical
approaches have failed. Azithromycin seems a promising drug because of a number of
reasons. First, it has a relatively long half-life, allowing a once daily administration of 500mg
during 3 days, hereby reducing the likelihood of noncompliance (Foulds et al., 1990). Second,
azithromycin demonstrates limited adverse effects (Oteo et al., 2010). At least in a number of
clinical studies, azithromycin significantly improved the outcome of non-surgical SRP in the
treatment of periodontitis (Smith et al., 2002, Haffajee et al., 2007, Gomi et al., 2007), yet its
potentially additional value in the management of residual sites remains to be investigated.
Hence, the secondary objective was to evaluate the clinical outcome of adjunctive use of
azithromycin to non-surgical re-treatment of residual sites.
Materials and Methods
Patient Sample
A prospective, monocentre, single-masked, randomized controlled 12-month study was
conducted in adult patients with generalized advanced chronic periodontitis. Patients were
recruited between January 2009 and August 2009 at the specialist clinic of the Department of
Periodontology of the University of Ghent, Belgium. The study was conducted in accordance
with the Helsinki declaration of 1975 as revised in 2008 and the protocol was approved by the
ethical committee of the University Hospital of Ghent. Inclusion and exclusion criteria were
as follows.
Inclusion criteria
-
At least 35 years old
-
At least 20 teeth present
-
At least one site per quadrant with probing pocket depth (PPD) ≥6 mm, bleeding on
probing (BoP) and bone loss surpassing one third of the root length as assessed on
peri-apical radiographs
-
Signed informed consent
Exclusion criteria
-
Systemic disease
-
Subgingival instrumentation within 2 years prior to the study
-
Use of antibiotics within 6 months prior to the study
-
Compromised medical condition implying the need for prophylactic use of antibiotics
-
Subjects wearing removable prostheses or undergoing orthodontic therapy
-
Pregnancy or lactating female candidates
-
Confirmed or suspected intolerance to macrolides
Patients who used systemic antibiotics during follow-up beyond the study protocol were
excluded from that moment on. Third molars and sites adjacent to teeth that were extracted
prior to or in the course of periodontal therapy were excluded. Such exclusion was carried out
due to the recession of soft tissue occurring subsequent to extraction, which could bias the
analysis of clinical attachment level.
Screening and randomization
After screening, baseline data were recorded by one examiner (S.R.M.) who also performed
all registrations at subsequent timepoints. At baseline, full-mouth peri-apical radiographs
were taken. On the basis of these radiographs and clinical measurements, the prognosis of
each tooth was determined and teeth irrational to treat were extracted before or in the course
of periodontal treatment. Group allocation was based on a computer-generated list using
simple randomization provided by a study team member who was not clinically involved in
the study (J.C.). According to the list, patients were assigned to one of the two treatment
groups; scaling and root planing or surgery (figure 1). During the study period, the examiner
who performed the measurements was blinded to the type of treatment.
All treatment procedures were carried out by two periodontists (H.S. and K.P.) and surgical
procedures were supervised by the same clinician (I.W.). One month prior to baseline
registration, all patients were given meticulous instructions regarding self-performed oral
hygiene measures. This included manual toothbrushing along with interdental cleaning (TePe
toothbrushes and interdental brushes, TePe Munhygienprodukter AB
, Malmö, Sweden).
Two weeks afterwards as well as at all other timepoints (baseline, 3, 6 and 12 months), oral
hygiene was evaluated and reinforced, if necessary.
Group “scaling and root planing”
Patients allocated to this group received SRP using an ultrasonic device (Satelec P5
Newtron®, Acteon group, Bilbao, Spain) and manual curettes. The treatment was carried out
in 2 sessions (right side, left side) under local anesthesia with 1 week in between. There was
no time limitation imposed and the endpoint of treatment was reached when a smooth
calculus-free root surface was achieved as deemed by the clinician. Patients were provided
with a prescription of paracetamol 500mg. At 3 months, supragingival plaque and calculus
were removed, if spotted. Teeth were polished at each visit using rubber cups and a lowabrasive polishing paste (Zircate® prophy paste, Dentsply, Milford, DE, USA). Patients
showing residual pockets ≥6 mm deep at the 6 month re-assessment, were additionally treated
by means of systemic azithromycin (500mg, per os, once daily for 3 days) in conjunction to
non-surgical re-debridement of these sites. Other patients did not receive additional active
therapy. All patients were invited at 12 months to assess the final clinical outcome. Residual
pocket at 12 months underwent re-debridement.
Group “Surgery”
Patients allocated to this group received open flap debridement (access flap at all sites,
osseous re-contouring, soft tissue reposition) using an ultrasonic device (Satelec P5
Newtron®, Acteon group, Bilbao, Spain) and manual curettes. The treatment was performed
in 4 sessions (quadrant basis) with 1 week in between. Osseous surgery was done in the sense
of eliminating or reducing intra-osseous defects, hereby restoring a physiologic bone
architecture. If necessary, soft tissue was thinned out for better adaptation. There was no time
limitation imposed. Polylactic sutures (Vicryl Rapide, Ethicon, Johnson & Johnson, NJ,
United States) were used to obtain wound closure and these were removed after 7 days.
Patients were provided with a prescription of paracetamol 500mg. The follow-up of these
patients was identical to the follow-up of patients allocated to the SRP group (see above).
Again, patients with residual pockets received additional treatment at 6 months on the basis of
non-surgical re-debridement and systemic azithromycin. Residual pocket at 12 months
underwent re-debridement.
(Here approximately Figure 1 please)
Examinations
At baseline, 6 and 12 months, the following clinical recordings were sequentially registered
by the same clinician (S.R.M.).
1- Probing pocket depth (PPD) measured at 6 sites per tooth (mesial, central, distal; orally and
buccally) using a manual probe (CP15 UNC, Hu-Friedy, Chicago, IL, United States). At
follow-up, pockets ≤3mm in depth were defined as “closed” and pockets ≥6mm were defined
as “residual”.
2- Bleeding on probing (BoP) registered 15 seconds following pocket probing. A
dichotomous score (0: no bleeding; 1: bleeding) was given. The gathered data were
subsequently transformed into percentage of bleeding sites.
3- Plaque index (PI) (Quigley & Hein, 1962) measured at six sites per tooth (mesial, central,
distal; orally and buccally) following the application of a plaque disclosing agent (Svenska®,
Svenska Dental Instrument AB, Upplands, Väsby, Sweden). The scores ranged from 0 to 5.
4- Clinical attachment level (CAL) calculated for each site as the sum of PPD and gingival
recession (recession was given a positive value, overgrowth a negative one).
5- Patient discomfort was assessed using a VAS score (ranging from “no pain” to “extremely
intolerable pain”) one week after each treatment session in a separate room without clinicians
being present. The total number of painkillers taken by the patient after each treatment session
was also noted.
The breakdown of chair-time and cost is presented in table 1. The actual chair-time relating to
the first active treatment phase was recorded for each patient. The chair-time and associated
cost for all other visits were estimated based on the standard time schedule imposed by the
administration of the University Hospital. Residual pockets and cost-effectiveness were
considered as primary outcome variables, while others were considered as secondary.
(Here approximately Table 1 please )
Calibration session
The clinician (S.R.M.) who performed all clinical recordings was calibrated prior to the start
of the study. Four patients suffering from chronic periodontitis were enrolled for this purpose.
Duplicate measurements (n=489) for PI, PPD and CAL were collected with an interval of 30
minutes between the first and the second recording.
Sample size calculation
Calculations were based on data from a randomized controlled study comparing different
types of periodontal therapy in patients with advanced periodontal disease (Cosyn et al.,
2007). Based on a mean difference in PPD of 0.5mm between the groups at 6 months,
standard deviations of 0.55 mm for both groups, an alpha error of 5% and statistical power of
80%, a sample size of 15 patients per group was found. To compensate for drop-outs, 20
patients were included in the SRP group and 20 in the surgery group.
Statistical analysis
Data analysis was performed using the patient as the experimental unit. Data from all patients
were utilized, as an intention-to-treat analysis was conducted. Intra-examiner repeatability on
PI, PPD and CAL was evaluated using Spearman’s correlation coefficient. Mean values were
calculated for all continuous variables and frequency distributions were constructed for
categorical variables. The Mann-Whitney test was used to compare groups in terms of age,
mean number of teeth per patient (overall and split up into molars and teeth with furcation
involvement), mean baseline PPD (full-mouth and per stratum), mean baseline CAL (fullmouth and per stratum), mean baseline PI (full-mouth), mean baseline BOP (full-mouth),
mean chair-time , mean cost, mean VAS scores and the percentage of closed and residual
pockets. The Fisher’s exact test was used to compare the number of drop-outs and
males/females between the groups. PPD, CAL, PI and BOP alterations were evaluated using
repeated measures ANOVA with the patient as a random factor and the group and time as
fixed factors. The level of significance was set at 0.05.
Results
Forty patients were initially recruited; yet, 1 patient withdrew from the study prior to
treatment. Of the 39 patients undergoing treatment, 35 patients completed the 12-month
follow-up period. A description of the patient sample is given in table 2. Three patients
dropped out due to lack of compliance with the scheduled appointments and 1 patient
withdrew from the study after the first flap operation due to “intolerable pain” as described by
the patient. As can be seen in table 1, there were no significant differences between the groups
at baseline in terms of drop-outs, gender, age, smoking habits, number of teeth and degree of
periodontal destruction (p≥0.061). An individual smoking more than 5 cigarettes per day was
considered a smoker. Intra-examiner repeatability on PI, PPD and CAL was satisfying
(Spearman’s correlation coefficients ≥0.851; p<0.001).
(Here approximately table 2 please)
Results up to 6-months
Closed and residual pockets
At the 6-month reassessment, on average 77.3%±14.0 of the pockets in the SRP group were ≤
3mm deep and were considered “closed” by definition, whilst in the surgery group 88.8%±8.3
of the pockets were “closed”. At the same time point, 8.6%±9.4 of the pockets in the SRP
group were ≥ 6mm and were considered “residual” by definition. In the surgery group this
amounted to 1.0%±1.8. The differences between the groups in terms of both “closed” and
“residual” pockets were statistically significant at 6 months (p<0.001) (fig. 2).
(Here approximately Figure 2 please)
Cost-effectiveness
Chair-time was significantly longer for surgery than for SRP (315 min vs. 441 min, p<0.001)
and resulted in 7.6% less residual pockets at 6 months as already described (Table 3). This
difference in chair-time corresponded to a disparity in cost of 746 Euro in favor of SRP.
Hence, the ICER at 6 months amounted to 98, meaning an extra 98 Euro would be spent on
average by the patient to achieve 1% extra reduction in the proportion of residual pockets.
(Here approximately Table 3 please)
Probing pocket depth (PPD) alterations
Initially, there were no significant differences between the groups with respect to PPD
(p=0.663). Baseline mean full-mouth PPD was 3.7±0.7mm for the SRP group and 3.6±0.5 for
the surgery group. At 6 months, both groups showed significant reduction compared to
baseline with mean full-mouth PPD of 2.9±0.6mm for the SRP group and 2.7±0.3mm for the
surgery group (p<0.001), yet a significant treatment-time interaction could not be
demonstrated (p=0.100). PPD data were also analyzed on the basis of different pocket depth
strata, defined as follows: shallow (≥ 3mm), medium (4-5mm) and deep (≥6mm). All strata
followed a similar course as full-mouth PPD demonstrating a significant time effect
(p<0.001), yet a significant treatment-time interaction could not be demonstrated (p≥0.082)
(Table 4).
CAL alterations
Initially, there were no significant differences between the groups in terms of CAL (p=0.325)
as mean full-mouth CAL was 5.0±1.0mm for the SRP group and 4.7±0.6 for the surgery
group. At 6 months, both groups showed significant reduction compared to baseline with
mean full-mouth CAL of 4.9±0.2mm for the SRP group and 4.4±0.1mm for the surgery group
(p<0.001), without any significant treatment-time interaction (p=0.811). CAL data were also
analyzed on the basis of different pocket depth strata. All strata followed a similar course as
full-mouth CAL demonstrating a significant time-effect (p<0.001). No significant treatmenttime interaction could be established (p≥0.081) (Table 4).
(Here approximately Table 4 please)
PI and BOP alterations
There were no significant differences between the groups at baseline with regard to PI values,
pointing to 1.1±0.4 and 1.3±0.5 for SRP and surgery, respectively. At 6 months, a significant
reduction was observed in both groups as PI amounted to 0.7±0.4 and 0.7±0.4 for SRP and
surgery, respectively (p<0.001). A significant treatment-time interaction could not be
demonstrated (p=0.317).
No significant differences were found between the groups at baseline in terms of BOP
(p=0.694), pointing to 70.1%±22.0 and 68.0%±22.9 for SRP and surgery, respectively. At 6
months, both groups demonstrated a significant reduction in BOP (p<0.001) as BOP values
amounted to 21.9%±12.6 and 15.9%±2.9 for SRP and surgery, respectively. No significant
treatment-time interaction was found (p=0.903).
Patient discomfort
The mean VAS score for the SRP group was 40±19, while it amounted to 43±32 for the
surgery group. The difference between the groups was not statistically significant (p=0.780).
The mean number of painkillers taken by the patients in the SRP group was comparable to the
amount taken by patients in the surgery group (p=0.272) pointing to 10.6 and 7.5,
respectively.
6-to 12-month results
Closed and residual pockets
As shown in figure 2, 14 patients out of 17 in the SRP group showed residual pockets at 6
months, while in the surgery group 6 patients out of 18 met this criterion. At the 12-month reassessment, the 14 patients of the SRP group who received the second phase of treatment,
showed significant improvements compared to the 6-month re-assessment in terms of fullmouth PPD, CAL and BOP. Similar observations were found for the 6 patients of the surgery
group who received the second phase of treatment. The percentage of “closed” and “residual”
pockets also showed significant improvements between 6 and 12 months in both groups,
finally pointing to 87.4±5.0% and 1.0±1.8%, respectively for the SRP group (p<0.001). In the
surgery group, the percentage of “closed” and “residual” pockets were 91.0±8.0% and
1.0±1.2% at study termination, respectively (p≤0.027).
When comparing the groups with each other in terms of the percentage of residual and closed
pockets at study termination, there were no statistically significant differences (p≥0.130).
Cost-effectiveness
As can be seen in table 3, chair-time and associated cost between 6 and 12 months were
statistically significantly lower for the surgery group compared to SRP. That is, 27 minutes on
average could be saved by surgery corresponding to a cost saving of 45 Euro. Yet, this cost
saving could not offset the higher initial cost of surgery when calculating the total cost of up
to 12 months (1445 Euros vs. 745 Euros, p<0.001). This is especially important since the
outcome in the proportion of residual pockets was very low and similar after 1 year in both
groups (< 1%).
Discussion
In this randomized controlled trial, surgery as initial treatment was compared to SRP in
patients with advanced periodontal disease. Both therapies were effective in reducing PPD,
CAL and BOP, which is in accordance with a number of studies (Lindhe et al., 1984,
Pihlstrom et al., 1984, Ramfjord et al., 1987, Badersten et al., 1990, Serino et al., 2001). At
least in terms of mean changes up to 6 months, surgery performed equally well as SRP.
Interestingly, Serino and co-workers (2001) evaluated the outcome of immediate surgery
versus SRP in single-rooted teeth and demonstrated significantly more PPD and CAL
reduction following surgical treatment, particularly in deep pockets. Although this could not
be confirmed in this study, frequency distributions on residual and closed sites did reveal
significant disparities between the groups with surgery delivering 7.6% less residual pockets
than SRP. This finding illustrates that the assessment of clinical effectiveness on the basis of
mean values can be misleading as residual pockets might be overlooked in the shadow of
calculating such mean values. However, the prevalence of residual sites is imperative as these
have been shown to be at risk for additional attachment loss, which in turn increases the risk
for tooth loss (Claffey and Egelberg, 1995, Matuliene et al., 2008).
In the present study, surgery took significantly more time than SRP. Consequently, surgery
imposed significantly higher cost on the patient than SRP, thereby confirming our research
hypothesis. Calculation revealed that patients undergoing surgical treatment would need to
pay on average an extra 746 Euro up to 6 months for delivering 7.6% less residual pockets
than SRP. This difference could be reduced to 700 Euro at 12 months since surgery reduced
the need for supportive treatment. Considering the fact that both treatment modalities were
equally effective in the end in terms of residual pockets (< 1%), one could question the costeffectiveness of surgery. On the other hand, surgery reduced the need for antibiotic therapy by
more than half (6 vs. 14 patients). This is important as it lowers the risk for antibiotic
resistance and its associated cost for society.
To the best of our knowledge there are no comparable studies on cost-effectiveness of
periodontal therapy in the literature. Economic assessment of periodontal treatment can be
approached from different angles using cost-effectiveness, cost-utility or cost-benefit analyses
(Antczak-Bouckoms and Weinstein, 1987, Gaunt et al., 2008). A cost-utility analysis was
performed by Antczak-Bouckoms and Weinstein (1987) using an index called “qualityadjusted tooth years” (QATY). They concluded that SRP imposed lower cost on the patient
than surgical alternatives, while maximizing expected QATYs. However, the study was
criticized for not taking the maintenance phase into account (Kraal, 1988). In addition, it
seems that the side effects of treatment alternatives were heavily weighted, hereby somewhat
overshadowing the clinical effectiveness of therapy. Despite the fact that our results also
showed higher cost for surgery, the present study cannot be compared to the study of
Antczak-Bouckoms and Weinstein (1987). For one thing, we performed a cost-effectiveness
analysis, while Antczak-Bouckoms and Weinstein (1987) assessed cost-utility. Furthermore,
well-defined and generally accepted success criteria to which cost can be related, would be
needed for an unbiased comparison. Tooth loss can be considered an ideal variable for the
assessment of periodontal treatment effectiveness in the long term (Serino et al., 2001,
Rosling et al., 2001). However, short-term studies can only adopt surrogate variables such as
residual sites.
In the current trial, a second phase of treatment commenced for patients with residual sites at
6 months due to the ethical obligation of limiting ongoing disease. Azithromycin was chosen
for this purpose given earlier promising results in the context of periodontal therapy (Smith et
al., 2002, Gomi et al., 2007). The combination of SRP and systemic azithromycin led to
significant improvements in PPD, CAL, BOP and the percentage of residual pockets.
A number of limitations must be considered when interpreting the results of the present study.
First, a model for cost assessment was used in this study, which may compromise the external
validity of research findings. In this respect, variability in terms of surgical skills and
associated chair-time and variability in the charge for certain care, may have a substantial
impact on final treatment cost. In addition, one should take into account that chair-time for
aftercare was estimated in this study based on the standard time schedule imposed by the
administration of the University Hospital. Second, elucidating the exact effects of
azithromycin on the final outcome might be complicated considering no placebo was used in
this trial. On the other hand, repeated SRP has been shown to be of little value (Badersten et
al., 1984), and therefore a relevant impact of Azithromycin seems realistic.
In conclusion, immediate surgery and SRP, both followed by re-debridement and systemic
azithromycin at 6 months, were equally effective in terms of clinical outcome demonstrating
less than 1 % residual pockets at 12 months. Surgery imposed an extra 746 Euro on the
patient up to 6 months when compared to SRP. At 12 months, 46 Euro of this amount could
be offset as a result of a reduced need for supportive care. Although the final cost disparity of
700 Euro remains discernible, surgery reduced the need for antibiotic therapy by more than 50
%.
Acknowledgements
The authors wish to thank Mrs. Iris Wyn for her valuable contribution to this study.
References
Antczak-Bouckoms, A. A. & Weinstein, M. C. (1987) Cost-effectiveness analysis of periodontal disease
control. J Dent Res 66, 1630-1635.
Axelsson, P. & Lindhe, J. (1981) The significance of maintenance care in the treatment of periodontal
disease. J Clin Periodontol 8, 281-294.
Badersten, A., Nilveus, R. & Egelberg, J. (1984) Effect of nonsurgical periodontal therapy. III. Single
versus repeated instrumentation. J Clin Periodontol 11, 114-124.
Badersten, A., Nilveus, R. & Egelberg, J. (1990) Scores of plaque, bleeding, suppuration and probing
depth to predict probing attachment loss. 5 years of observation following nonsurgical
periodontal therapy. J Clin Periodontol 17, 102-107.
Claffey, N. & Egelberg, J. (1995) Clinical indicators of probing attachment loss following initial
periodontal treatment in advanced periodontitis patients. J Clin Periodontol 22, 690-696.
Cosyn, J., Wyn, I., De Rouck, T. & Sabzevar, M. M. (2007) Subgingival chlorhexidine varnish
administration as an adjunct to same-day full-mouth root planing. I. Clinical observations. J
Periodontol 78, 430-437. doi:10.1902/jop.2007.060221.
Foulds, G., Shepard, R. M. & Johnson, R. B. (1990) The pharmacokinetics of azithromycin in human
serum and tissues. J Antimicrob Chemother 25 Suppl A, 73-82.
Gaunt, F., Devine, M., Pennington, M., Vernazza, C., Gwynnett, E., Steen, N. & Heasman, P. (2008)
The cost-effectiveness of supportive periodontal care for patients with chronic periodontitis.
J Clin Periodontol 35, 67-82. doi:CPE1261 [pii]
10.1111/j.1600-051X.2008.01261.x.
Gomi, K., Yashima, A., Nagano, T., Kanazashi, M., Maeda, N. & Arai, T. (2007) Effects of full-mouth
scaling and root planing in conjunction with systemically administered azithromycin. J
Periodontol 78, 422-429. doi:10.1902/jop.2007.060247.
Haffajee, A. D., Torresyap, G. & Socransky, S. S. (2007) Clinical changes following four different
periodontal therapies for the treatment of chronic periodontitis: 1-year results. J Clin
Periodontol 34, 243-253. doi:CPE1040 [pii]
10.1111/j.1600-051X.2006.01040.x.
Heitz-Mayfield, L. J., Trombelli, L., Heitz, F., Needleman, I. & Moles, D. (2002) A systematic review of
the effect of surgical debridement vs non-surgical debridement for the treatment of chronic
periodontitis. J Clin Periodontol 29 Suppl 3, 92-102; discussion 160-102. doi:012 [pii].
Kraal, J. H. (1988) Cost-effectiveness analysis of periodontal disease control. J Dent Res 67, 611.
Lindhe, J. & Nyman, S. (1975) The effect of plaque control and surgical pocket elimination on the
establishment and maintenance of periodontal health. A longitudinal study of periodontal
therapy in cases of advanced disease. J Clin Periodontol 2, 67-79.
Lindhe, J., Westfelt, E., Nyman, S., Socransky, S. S. & Haffajee, A. D. (1984) Long-term effect of
surgical/non-surgical treatment of periodontal disease. J Clin Periodontol 11, 448-458.
Matuliene, G., Pjetursson, B. E., Salvi, G. E., Schmidlin, K., Bragger, U., Zwahlen, M. & Lang, N. P.
(2008) Influence of residual pockets on progression of periodontitis and tooth loss: results
after 11 years of maintenance. J Clin Periodontol 35, 685-695. doi:CPE1245 [pii]
10.1111/j.1600-051X.2008.01245.x.
Oteo, A., Herrera, D., Figuero, E., O'Connor, A., Gonzalez, I. & Sanz, M. (2010) Azithromycin as an
adjunct to scaling and root planing in the treatment of Porphyromonas gingivalis-associated
periodontitis: a pilot study. J Clin Periodontol 37, 1005-1015. doi:CPE1607 [pii]
10.1111/j.1600-051X.2010.01607.x.
Pihlstrom, B. L., Oliphant, T. H. & McHugh, R. B. (1984) Molar and nonmolar teeth compared over 6
1/2 years following two methods of periodontal therapy. J Periodontol 55, 499-504.
Ramfjord, S. P., Caffesse, R. G., Morrison, E. C., Hill, R. W., Kerry, G. J., Appleberry, E. A., Nissle, R. R. &
Stults, D. L. (1987) 4 modalities of periodontal treatment compared over 5 years. J Clin
Periodontol 14, 445-452.
Rosling, B., Serino, G., Hellstrom, M. K., Socransky, S. S. & Lindhe, J. (2001) Longitudinal periodontal
tissue alterations during supportive therapy. Findings from subjects with normal and high
susceptibility to periodontal disease. J Clin Periodontol 28, 241-249.
Serino, G., Rosling, B., Ramberg, P., Socransky, S. S. & Lindhe, J. (2001) Initial outcome and long-term
effect of surgical and non-surgical treatment of advanced periodontal disease. J Clin
Periodontol 28, 910-916. doi:281003 [pii].
Smith, S. R., Foyle, D. M., Daniels, J., Joyston-Bechal, S., Smales, F. C., Sefton, A. & Williams, J. (2002)
A double-blind placebo-controlled trial of azithromycin as an adjunct to non-surgical
treatment of periodontitis in adults: clinical results. J Clin Periodontol 29, 54-61. doi:290109
[pii].
Table 1. Chair-time and cost calculation algorithm
Baseline up to 6 months
Baseline diagnosis (60’, 100€)
Initial treatment (SRP: 100€/h, Surgery: 200€/h)
3 months: supragingival plaque control (30’, 50€)
6 months: re-evaluation (30’, 50€)
6 to 12-month analysis
6 months: supportive treatment (30’, 50€) + supplement of 15’
and 25€ per quadrant with residual pockets
12 months: re-evaluation (30’, 50€)
12 months: supportive treatment (30’, 50€) + supplement of 15’
and 25€ per quadrant with residual pockets
Table 2. Overview of the study population at baseline
Treatment groups
SRP
Surgery
Total
No. of
Enrolled
20
20-1*
39
patients
Drop-out
3
1
4
p=0.322
Gender (male/female)
9/11
9/10
18/21
p=0.560
Mean age (range)
Smoker
57.7(35.0-
51.2(35.0-
54.6(35.0-79.0)
79.0)
75.0)
p=0.061
5
5
10
p=0.600
Mean number of teeth /
24.7 (22-28)
25.4 (22-30)
patient (range)
Mean number of molars /
p=0.259
5.9 (4-8)
6.2 (4-8)
patient (range)
Mean number of teeth with
25.0
6.0
p=0.408
4.4 (3-6)
4.5 (3-6)
4.4
p=0.678
furcation involvement /
patient (range)
Mean full-mouth PPD (±
3.7 (± 0.7)
3.6 (± 0.5)
p=0.663
SD)
Mean full-mouth CAL (±
5.0 (± 1.0)
4.7 (± 0.6)
4.8 (± 0.9)
p=0.325
SD)
Mean full-mouth PI (± SD)
3.6 (± 0.6)
1.1±0.4
1.3±0.5
1.19 (± 0.6)
p=0.191
Mean full-mouth BOP (±
SD)
* 1 patient was never treated
SD Standard deviation
70.1% (±
22.0)
68.0% (± 22.9)
69.9% (± 22.1)
p=0.694
Table 3. Chair-time and estimated imposed cost on the patient for the two treatment arms
Chair-time
up to 6
months
Cost up to 6
months
Chair-time 612 months
Cost 6 -12
months
Total cost up
to 12 months
SRP group
315 (240360)
525 (400600)
131 (90-150)
219 (150250)
745 (625850)
Surgery
group
441 (400480)
1271 (12001400)
104 (90-165)
174 (150275)
1445 (12501650)
Inter-group
p-value
p<0.001
p<0.001
p=0.002
p=0.002
p<0.001
Mean (range)
Table 4. The evolution of PPD and CAL through the first 6 months of the study for each
pocket depth stratum (± Standard deviation)
Timepoint
Outcome variable
PPD (shallow
pockets)
PPD (medium
pockets)
PPD (deep
pockets)
CAL (shallow
pockets)
CAL (medium
pockets)
CAL (deep
pockets)
Inter-group
p-value
Baseline
3 months
6 months
SRP: 2.7±0.4
Surgery:
2.6±0.2
SRP: 4.2±0.3
Surgery:
4.4±0.3
SRP: 6.3±0.7
Surgery:
6.2±0.6
SRP: 4.1±0.8
Surgery:
3.6±0.7
SRP: 5.8±0.9
Surgery:
5.6±0.5
SRP: 7.9±1.1
Surgery:
7.3±0.7
SRP: 2.4±0.2
Surgery: 2.3±0.2
SRP: 2.4±0.2
Surgery: 2.3±0.2
p=0.193
SRP: 3.0±0.3
Surgery: 2.8±0.3
SRP: 3.0±0.3
Surgery: 2.8±0.2
p=0.082
SRP: 3.3±0.6
Surgery: 3.0±0.3
SRP: 3.4±0.6
Surgery: 3.0±0.3
p=0.449
SRP: 4.0±0.8
Surgery: 3.7±0.7
SRP: 4.0±0.8
Surgery: 3.8±0.7
p=0.081
SRP: 5.3±0.9
Surgery: 5.1±0.5
SRP: 5.4±0.9
Surgery: 5.1±0.5
p=0.133
SRP: 6.8±1.0
Surgery: 6.1±0.5
SRP: 6.9±1.0
Surgery: 6.1±0.5
p=0.577
Figure Legends:
Figure 1: The study flowchart
Figure 2: Evolution of the periodontal health of the study population during the study period